WorldWideScience

Sample records for experiments simulating igscc

  1. Winning the battle against IGSCC

    International Nuclear Information System (INIS)

    Riccardella, P.C.; Giannuzzi, A.J.; Childs, W.J.

    1992-01-01

    Intergranular stress corrosion cracking (IGSCC) in austenitic stainless steel piping began to be a widespread problem in Boiling Water Reactors (BWRs) in 1974. Now utility-sponsored research efforts through EPRI, the NRC and the nuclear steam supply vendor in the USA, have produced significant progress in understanding the causes of IGSC. These research projects have also yielded remedial measures which have been effective in reducing or eliminating the problem in both new and most operating BWRs. (author)

  2. The electrochemistry of IGSCC mitigation

    International Nuclear Information System (INIS)

    Macdonald, D.D.

    2002-01-01

    A brief review is presented of the electrochemical mitigation of intergranular stress corrosion cracking (IGSCC) in watercooled reactor heat transport circuit structural materials. Electrochemical control and mitigation is possible because of the existence of a critical potential for intergranular stress corrosion cracking and due to the feasibility of modifying the environment to displace the corrosion potential to a value that is more negative than the critical value. However, even in cases where the corrosion potential cannot be displaced sufficiently in the negative direction to become more negative than the critical potential, considerable advantage is accrued, because of the roughly exponential dependence of the crack growth rate on potential. The most important parameters in affecting electrochemical control over the corrosion potential and crack growth rate are the kinetic parameters (exchange current densities and Tafel constants) for the redox reactions involving the principal radiolysis products of water (O 2 , H 2 H 2 O 2 ), external solution composition (concentrations of O 2 , H 2 O 2 , and H 2 ), flow velocity, and the conductivity of the bulk environment. The kinetic parameters for the redox reactions essentially determine the charge transfer impedance of the steel surface, which is shown to be one of the key parameters in affecting the magnitude of the coupling current and hence the crack growth rate. The exchange current densities, in particular, are amenable to control by catalysis or inhibition, with the result that surface modification techniques are highly effective in controlling and mitigating intergranular stress corrosion cracking in reactor coolant circuit materials. (orig.)

  3. Simulated experiments

    International Nuclear Information System (INIS)

    Bjerknes, R.

    1977-01-01

    A cybernetic model has been developed to elucidate some of the main principles of the growth regulation system in the epidermis of the hairless mouse. A number of actual and theoretical biological experiments have been simulated on the model. These included simulating the cell kinetics as measured by pulse labelling with tritiated thymidine and by continuous labelling with tritiated thymidine. Other simulated experiments included steady state, wear and tear, painting with a carcinogen, heredity and heredity and tumour. Numerous diagrams illustrate the results of these simulated experiments. (JIW)

  4. Evaluation of the IGSCC(Intergranular Stress Corrosion Cracking) resistance of inconel alloys by static potential method in high temperature and high pressure environment

    International Nuclear Information System (INIS)

    Maeng, Wan Young; Nam, Tae Woon

    1997-01-01

    Inconel alloys which have good high temperature mechanical properties and corrosion resistance have been used extensively as steam generator tube of nuclear power plants. There have been some reports on the intergranular stress corrosion cracking (IGSCC) failure problems in steam generator tubes of nuclear reactors. In order to evaluate the effects of heat treatment and composition on the IGSCC behavior of inconel alloys in simulated nuclear reactor environment, four different specimens (inconel 600 MA, 600 TT, 690 MA and 690 TT) were prepared and tested by eletrochemical method. Static potential tests for stressed C-ring type inconel specimens were carried out in 10% NaOH solution at 300 deg C (75 atm). It was found that IGSCC was initiated in inconel 600 MA specimen, but the other three specimens were not cracked. Based on the gradients of corrosion current density of the four specimens as a function of test time, thermally treated alloys show better IGSCC resistance than mull-annealed alloys, and inconel 690 TT has better passivation characteristic than inconel 600 MA. Inconel 690 TT shows clear periodic passivation that indicates good SCC resistance. The good IGSCC resistance of inconel 690 TT is due to periodic passivation characteristics of surface layer. (author)

  5. The electrochemistry of IGSCC mitigation in BWR coolant circuits

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, D.D. [Center for Electrochemical Science and Technology, The Pennsylvania State Univ., University Park, PA (United States)

    2002-07-01

    A brief review is presented of the electrochemical mitigation of IGSCC in water-cooled reactor heat transport circuit structural materials. Electrochemical control and mitigation is possible, because of the existence of a critical potential for IGSCC and by the feasibility of modifying the environment to displace the corrosion potential (ECP) to a value that is more negative than the critical value. However, even in cases where the ECP cannot be displaced sufficiently in the negative direction to become more negative than the critical potential, considerable advantage is accrued, because of the roughly exponential dependence of crack growth rate on potential. The most important parameters in affecting electrochemical control over the ECP and crack growth rate are the kinetic parameters (exchange current densities and Tafel constants) for the redox reactions involving the principal radiolysis products of water (O{sub 2}, H{sub 2}, H{sub 2}O{sub 2}), external solution composition (concentrations of O{sub 2}, H{sub 2}O{sub 2}, and H{sub 2}), flow velocity, and the conductivity of the bulk environment. The kinetic parameters for the redox reactions essentially determine the charge transfer impedance of the steel surface, which is shown to be one of the key parameters in affecting the magnitude of the coupling current and hence the crack growth rate. The exchange current densities, in particular, are amenable to control by catalysis or inhibition, with the result that surface modification techniques are highly effective in controlling and mitigating IGSCC in reactor coolant circuit materials. (authors)

  6. Laguna Verde U2 NPP / reactor vessel shroud IGSCC susceptibility assessment and its inspections results

    International Nuclear Information System (INIS)

    Fernandez, G.

    2006-01-01

    This paper shows the IGSCC behavior in Laguna Verde Unit 1 and 2. LVNPP 1 and 2 have identical material and structural designs as well as a similar operational water chemistry and neutron fluency conditions. However, IGSCC behavior in core shroud welds are strongly depending on fabrication and construction residual stresses conditions for each of them. (author)

  7. Effect of chemical compositions and heat treatment on IGSCC resistance for strain hardened low carbon austenitic stainless steels in oxygenated water

    International Nuclear Information System (INIS)

    Yonezawa, T.; Kanasaki, H.; Fujimoto, K.; Taneike, M.; Ooki, S.; Sueishi, Y.; Tezuka, H.; Takamori, K.; Suzuki, S.

    2011-01-01

    In order to develop the highly resistant alternative materials to intergranular stress corrosion cracking (IGSCC) for the non-sensitized and strain hardened low carbon austenitic stainless steel in oxygenated water, the effects of chemical compositions and heat treatment conditions on the IGSCC resistance and stacking fault energy (SFE) values were studied for 33 laboratory melted steels and commercial type 310S stainless steel. The IGSCC resistance for test materials was compared by the maximum crack length, average crack length and cracked area in fatigue pre-cracked CT specimens after SCC test in oxygenated high temperature water. SFE values for these test materials were measured by the transmission electron microscopy on the width of isolated extended dislocations under g-3g weak beam condition for thin foils taken from the test materials, in this study. From these experiments, the effects of the chromium, molybdenum, nitrogen, silicon and manganese contents on the SCC resistance for non-aged materials were not so pronounced in this study. It is strongly suggested that the SFE value is a key parameter for the IGSCC resistance of the aged or non-aged and strain hardened low carbon austenitic stainless steels. (authors)

  8. Simulation - modeling - experiment; Simulation - modelisation - experience

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    After two workshops held in 2001 on the same topics, and in order to make a status of the advances in the domain of simulation and measurements, the main goals proposed for this workshop are: the presentation of the state-of-the-art of tools, methods and experiments in the domains of interest of the Gedepeon research group, the exchange of information about the possibilities of use of computer codes and facilities, about the understanding of physical and chemical phenomena, and about development and experiment needs. This document gathers 18 presentations (slides) among the 19 given at this workshop and dealing with: the deterministic and stochastic codes in reactor physics (Rimpault G.); MURE: an evolution code coupled with MCNP (Meplan O.); neutronic calculation of future reactors at EdF (Lecarpentier D.); advance status of the MCNP/TRIO-U neutronic/thermal-hydraulics coupling (Nuttin A.); the FLICA4/TRIPOLI4 thermal-hydraulics/neutronics coupling (Aniel S.); methods of disturbances and sensitivity analysis of nuclear data in reactor physics, application to VENUS-2 experimental reactor (Bidaud A.); modeling for the reliability improvement of an ADS accelerator (Biarotte J.L.); residual gas compensation of the space charge of intense beams (Ben Ismail A.); experimental determination and numerical modeling of phase equilibrium diagrams of interest in nuclear applications (Gachon J.C.); modeling of irradiation effects (Barbu A.); elastic limit and irradiation damage in Fe-Cr alloys: simulation and experiment (Pontikis V.); experimental measurements of spallation residues, comparison with Monte-Carlo simulation codes (Fallot M.); the spallation target-reactor coupling (Rimpault G.); tools and data (Grouiller J.P.); models in high energy transport codes: status and perspective (Leray S.); other ways of investigation for spallation (Audoin L.); neutrons and light particles production at intermediate energies (20-200 MeV) with iron, lead and uranium targets (Le Colley F

  9. Human Simulated Diving Experiments.

    Science.gov (United States)

    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. Simulation - modeling - experiment

    International Nuclear Information System (INIS)

    2004-01-01

    After two workshops held in 2001 on the same topics, and in order to make a status of the advances in the domain of simulation and measurements, the main goals proposed for this workshop are: the presentation of the state-of-the-art of tools, methods and experiments in the domains of interest of the Gedepeon research group, the exchange of information about the possibilities of use of computer codes and facilities, about the understanding of physical and chemical phenomena, and about development and experiment needs. This document gathers 18 presentations (slides) among the 19 given at this workshop and dealing with: the deterministic and stochastic codes in reactor physics (Rimpault G.); MURE: an evolution code coupled with MCNP (Meplan O.); neutronic calculation of future reactors at EdF (Lecarpentier D.); advance status of the MCNP/TRIO-U neutronic/thermal-hydraulics coupling (Nuttin A.); the FLICA4/TRIPOLI4 thermal-hydraulics/neutronics coupling (Aniel S.); methods of disturbances and sensitivity analysis of nuclear data in reactor physics, application to VENUS-2 experimental reactor (Bidaud A.); modeling for the reliability improvement of an ADS accelerator (Biarotte J.L.); residual gas compensation of the space charge of intense beams (Ben Ismail A.); experimental determination and numerical modeling of phase equilibrium diagrams of interest in nuclear applications (Gachon J.C.); modeling of irradiation effects (Barbu A.); elastic limit and irradiation damage in Fe-Cr alloys: simulation and experiment (Pontikis V.); experimental measurements of spallation residues, comparison with Monte-Carlo simulation codes (Fallot M.); the spallation target-reactor coupling (Rimpault G.); tools and data (Grouiller J.P.); models in high energy transport codes: status and perspective (Leray S.); other ways of investigation for spallation (Audoin L.); neutrons and light particles production at intermediate energies (20-200 MeV) with iron, lead and uranium targets (Le Colley F

  11. Grain boundary chromium concentration effects on the IGSCC and IASCC of austenitic stainless steels

    International Nuclear Information System (INIS)

    Bruemmer, S.M.; Arey, B.W.; Charlot, L.A.

    1993-08-01

    Comparisons are made between grain boundary composition and intergranular stress corrosion cracking (IGSCC) of 304 and 309 austenitic stainless steels in high-temperature water environments. Chromium depletion had the dominant effect on cracking resistance with the extent of IG cracking controlled by the interfacial chromium concentration. The minimum chromium concentration required to promote cracking was a function of the applied strain rate during slow-strain-rate tensile tests in 288 C air-saturated water. Depletion from bulk levels of 18 wt% to ∼13.5 wt% Cr at grain boundaries prompted 100% IG cracking at a strain rate of 1 x 10 -6 s -1 , while embrittlement was observed with only a slight depletion to ∼17 wt% at 2 x 10 -7 s -1 . Insights into critical interfacial compositions promoting IGSCC are discussed in reference to cracking of irradiated stainless steel nuclear reactor core components

  12. Monte Carlo simulation of experiments

    International Nuclear Information System (INIS)

    Opat, G.I.

    1977-07-01

    An outline of the technique of computer simulation of particle physics experiments by the Monte Carlo method is presented. Useful special purpose subprograms are listed and described. At each stage the discussion is made concrete by direct reference to the programs SIMUL8 and its variant MONTE-PION, written to assist in the analysis of the radiative decay experiments μ + → e + ν sub(e) antiνγ and π + → e + ν sub(e)γ, respectively. These experiments were based on the use of two large sodium iodide crystals, TINA and MINA, as e and γ detectors. Instructions for the use of SIMUL8 and MONTE-PION are given. (author)

  13. Bridging experiments, models and simulations

    DEFF Research Database (Denmark)

    Carusi, Annamaria; Burrage, Kevin; Rodríguez, Blanca

    2012-01-01

    understanding of living organisms and also how they can reduce, replace, and refine animal experiments. A fundamental requirement to fulfill these expectations and achieve the full potential of computational physiology is a clear understanding of what models represent and how they can be validated. The present...... of biovariability; 2) testing and developing robust techniques and tools as a prerequisite to conducting physiological investigations; 3) defining and adopting standards to facilitate the interoperability of experiments, models, and simulations; 4) and understanding physiological validation as an iterative process...... that contributes to defining the specific aspects of cardiac electrophysiology the MSE system targets, rather than being only an external test, and that this is driven by advances in experimental and computational methods and the combination of both....

  14. Laboratory results gained from cold worked type 316Ti under simulated PWR primary environment

    International Nuclear Information System (INIS)

    Devrient, B.; Kilian, R.; Koenig, G.; Widera, M.; Wermelinger, T.

    2015-01-01

    Beginning in 2005, intergranular stress corrosion cracking (IGSCC) of barrel bolts made from cold worked type 316Ti (German Material No. 1.4571 K) was observed in several S/KWU type PWRs. This mechanism was so far less understood for PWR primary conditions. Therefore an extended joint research program was launched by AREVA GmbH and VGB e.V. to clarify the specific conditions which contributed to the observed findings on barrel bolts. In the frame of this research program beneath the evaluation of the operational experience also laboratory tests on the general cracking behavior of cold worked type 316Ti material, which followed the same production line as for barrel bolt manufacturing in the eighties, with different cold work levels covering up to 30 % were performed to determine whether there is a specific susceptibility of cold worked austenitic stainless steel specimens to suffer IGSCC under simulated PWR primary conditions. All these slow strain rate tests on tapered specimens and component specimens came to the results that first, much higher cold work levels than used for the existing barrel bolts are needed for IGSCC initiation. Secondly, additional high active plastic deformation is needed to generate and propagate intergranular cracking. And thirdly, all specimens finally showed ductile fracture at the applied strain rates. (authors)

  15. Assessment of susceptibility of Type 304 stainless steel to intergranular stress corrosion cracking in simulated Savannah River Reactor environments

    International Nuclear Information System (INIS)

    Ondrejcin, R.S.; Caskey, C.R. Jr.

    1989-01-01

    Intergranular stress corrosion cracking (IGSCC) of Type 304 stainless steel rate tests (CERT) of specimens machined was evaluated by constant extension from Savannah River Plant (SRP) decontaminated process water piping. Results from 12 preliminary CERT tests verified that IGSCC occurred over a wide range of simulated SRP envirorments. 73 specimens were tested in two statistical experimental designs of the central composite class. In one design, testing was done in environments containing hydrogen peroxide; in the other design, hydrogen peroxide was omitted but oxygen was added to the environment. Prediction equations relating IGSCC to temperature and environmental variables were formulated. Temperature was the most important independent variable. IGSCC was severe at 100 to 120C and a threshold temperature between 40C and 55C was identified below which IGSCC did not occur. In environments containing hydrogen peroxide, as in SRP operation, a reduction in chloride concentration from 30 to 2 ppB also significantly reduced IGSCC. Reduction in sulfate concentration from 50 to 7 ppB was effective in reducing IGSCC provided the chloride concentration was 30 ppB or less and temperature was 95C or higher. Presence of hydrogen peroxide in the environment increased IGSCC except when chloride concentration was 11 ppB or less. Actual concentrations of hydrogen peroxide, oxygen and carbon dioxide did not affect IGSCC. Large positive ECP values (+450 to +750 mV Standard Hydrogen Electrode (SHE)) in simulated SRP environments containing hydrogen peroxide and were good agreement with ECP measurements made in SRP reactors, indicating that the simulated environments are representative of SRP reactor environments. Overall CERT results suggest that the most effective method to reduce IGSCC is to reduce chloride and sulfate concentrations

  16. Mechanical Contact Experiments and Simulations

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, P; Zhang, W.

    2011-01-01

    Mechanical contact is studied under dynamic development by means of a combined numerical and experimental investigation. The experiments are designed to allow dynamical development of non-planar contact areas with significant expansion in all three directions as the load is increased. Different....... The overall investigation serves for testing and validating the numerical implementation of the mechanical contact, which is one of the main contributions to a system intended for 3D simulation of resistance welding. Correct modelling of contact between parts to be welded, as well as contact with electrodes......, is crucial for satisfactory modelling of the resistance welding process. The resistance heating at the contact interfaces depends on both contact area and pressure, and as the contact areas develop dynamically, the presented tests are relevant for assessing the validity and accuracy of the mechanical contact...

  17. Nuclear waste repository simulation experiments

    International Nuclear Information System (INIS)

    Rothfuchs, T.; Wieczorek, K.; Feddersen, H.K.; Staupendahl, G.; Coyle, A.J.; Kalia, H.; Eckert, J.

    1986-12-01

    This document is the third joint annual report on the Cooperative German-American 'Brine Migration Tests' that are in progress at the Asse salt mine in the Federal Republic of Germany (FRG). This Government supported mine serves as an underground test facility for research and development (R and D)-work in the field of nuclear waste repository research and simulation experiments. The tests are designed to simulate a nuclear waste repository to measure the effects of heat and gamma radiation on brine migration, salt decrepitation, disassociation of brine, and gases collected. The thermal mechanical behavior of salt, such as room closure, stresses and changes of the properties of salt are measured and compared with predicted behavior. This document covers the following sections: Issues and test objectives: This section presents issues that are investigated by the Brine Migration Test, and the test objectives derived from these issues; test site: This section describes the test site location and geology in the Asse mine; test description: A description of the test configuration, procedures, equipment, and instrumentation is given in this section; actual test chronology: The actual history of the test, in terms of the dates at which major activities occured, is presented in this section. Test results: This section presents the test results observed to data and the planned future work that is needed to complete the test; conclusions and recommendations: This section summarizes the conclusions derived to date regarding the Brine Migration Test. Additional work that would be useful to resolve the issues is discussed. (orig.)

  18. Recent trends in the mitigation of the IGSCC through modifications in the water chemistry of BWR reactors; Tendencias recientes en la mitigacion del IGSCC mediante modificaciones en la quimica del agua de reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A.; Robles, E.F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    During the last years, the Nuclear Power stations had been that to adequate or to modify the parameters and operational conditions, attempting to maintain and to safeguard the integrity and functionality of its components and systems, as well as the personnel safety involved in its operation. In a Boiling water reactor (BWR), the chemical control of the water, constitutes one of the fundamental aspects to get a sure and reliable operation, having as main objectives: (a) The protection of the reactor vessel, of the structural materials of the same one and of the pipes and components of those recirculation systems against the Intergranular stress corrosion phenomena (IGSCC); (b) To guarantee the integrity of the nuclear fuel minimizing the corrosion phenomena in the fuel elements; and (c) The reduction of the operational dose of the personnel involved directly in the operation and maintenance by means of the control of the activated corrosion products. (Author)

  19. Simulation strategies for the LHC ATLAS experiment

    CERN Document Server

    Buckley, A; The ATLAS collaboration

    2010-01-01

    The ATLAS experiment, operational at the new LHC collider, is fully simulated using the Geant4 tool. The simulation program has been built within the ATLAS common framework Athena. The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for large-scale production of events on the LHC Computing Grid. This simulation requires many components, from the generators that simulate particle collisions, through packages simulating the response of the various detectors and triggers. All of these components come together under the ATLAS simulation infrastructure. The latest developments went into the direction to better represent the reality of the detector in all the possible details. The latest developments provide increased functionality and robustness. The full process is constantly monitored and profiled. Increased performance guarantee the best use of available resources without any degradation in the quality and accuracy of the simulation itself. In the presentation emphasis is...

  20. Labotratory Simulation Experiments of Cometary Plasma

    OpenAIRE

    MINAMI, S.; Baum, P. J.; Kamin, G.; White, R. S.; 南, 繁行

    1986-01-01

    Laboratory simulation experiment to study the interaction between a cometary plasma and the solar wind has been performed using the UCR-T 1 space simulation facility at the Institute of Geophysics and Planetary Physics, the University of California, Riverside. Light emitting plasma composed of Sr, Ba and/or C simulating cometary coma plasma is produced by a plasma emitter which interacts with intense plasma flow produced by a co-axial plasma gun simulating the solar wind. The purpose of this ...

  1. Recent trends in the mitigation of the IGSCC through modifications in the water chemistry of BWR reactors

    International Nuclear Information System (INIS)

    Diaz S, A.; Robles, E.F.

    2003-01-01

    During the last years, the Nuclear Power stations had been that to adequate or to modify the parameters and operational conditions, attempting to maintain and to safeguard the integrity and functionality of its components and systems, as well as the personnel safety involved in its operation. In a Boiling water reactor (BWR), the chemical control of the water, constitutes one of the fundamental aspects to get a sure and reliable operation, having as main objectives: (a) The protection of the reactor vessel, of the structural materials of the same one and of the pipes and components of those recirculation systems against the Intergranular stress corrosion phenomena (IGSCC); (b) To guarantee the integrity of the nuclear fuel minimizing the corrosion phenomena in the fuel elements; and (c) The reduction of the operational dose of the personnel involved directly in the operation and maintenance by means of the control of the activated corrosion products. (Author)

  2. Mechanical Contact Experiments and Simulations

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, P; Zhang, W.

    2011-01-01

    . The overall investigation serves for testing and validating the numerical implementation of the mechanical contact, which is one of the main contributions to a system intended for 3D simulation of resistance welding. Correct modelling of contact between parts to be welded, as well as contact with electrodes...... geometries and different materials are analyzed including contact between dissimilar materials. The numerical implementation is performed with a finite element computer program based on the irreducible flow formulation, and contact between deformable objects is modelled by applying the penalty method......, is crucial for satisfactory modelling of the resistance welding process. The resistance heating at the contact interfaces depends on both contact area and pressure, and as the contact areas develop dynamically, the presented tests are relevant for assessing the validity and accuracy of the mechanical contact...

  3. Operator training and the training simulator experience

    International Nuclear Information System (INIS)

    Mills, D.

    The author outlines the approach used by Ontario Hydro to train operators from the day they are hired as Operators-in-Training until they are Authorized Unit First Operators. He describes in detail the use of the simulator in the final year of the authorization program, drawing on experience with the Pickering NGS A simulator. Simulators, he concludes, are important aids to training but by no means all that is required to guarantee capable First Operators

  4. Understanding homelessness using a simulated nursing experience.

    Science.gov (United States)

    Barry, Charlotte D; Blum, Cynthia Ann; Eggenberger, Terry L; Palmer-Hickman, Candice L; Mosley, Rebecca

    2009-01-01

    Students have an opportunity to understand the full experience of being homeless using simulated community nursing situations with a high-fidelity simulator. The Community Nursing Practice Model provides a context for using this innovative teaching strategy to enable students to respond holistically to the needs of the homeless.

  5. Screening Experiments for Simulation : A Review

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2007-01-01

    This article reviews so-called screening in simulation; i.e., it examines the search for the really important factors in experiments with simulation models that have very many factors (or inputs). The article focuses on a most efficient and effec- tive screening method, namely Sequential

  6. Improving Investment Decisions with Simulated Experience

    OpenAIRE

    Bradbury, Meike A. S.; Hens, Thorsten; Zeisberger, Stefan

    2017-01-01

    We apply a new and innovative approach to communicating risks associated with financial products that should support investors in making better investment decisions. In our experiments, participants are able to gain "simulated experience” by random sampling of a previously described return distribution. We find that simulated experience considerably improves participants' understanding of the underlying risk-return profile and prompts them to reconsider their investment decisions and to choos...

  7. Simulation of integrated beam experiment designs

    International Nuclear Information System (INIS)

    Grote, D.P.; Sharp, W.M.

    2004-01-01

    Simulation of designs of an Integrated Beam Experiment (IBX) class accelerator have been carried out. These simulations are an important tool for validating such designs. Issues such as envelope mismatch and emittance growth can be examined in a self-consistent manner, including the details of injection, accelerator transitions, long-term transport, and longitudinal compression. The simulations are three-dimensional and time-dependent, and begin at the source. They continue up through the end of the acceleration region, at which point the data is passed on to a separate simulation of the drift compression. Results are be presented

  8. COMPASS Simulation for PHEBUS FPT-3 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jun Ho; Kim, Jongtae; Park, Rae-Jun; Son, Donggun; Kim, Dong Ha [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The objective of this paper is to assess the core degradation modeling in COMPASS code by simulating the PHEBUS FPT3 experiment. For the comparison purpose, the numerical simulation by using MELCOR 2.1 have also conducted for the FPT3 experiment. Consequently, COMPASS results of PHEBUS FPT3 have been compared with the experimental data and MELCOR results. For the purpose of COMPASS code validation, the numerical simulation for PHEBUS FPT3 experiment has been conducted. The temperature of the main component has been secured by using COMPASS code for a fuel, cladding, control rod and surrounding structure. And they are compared with that of experimental data as well as MELCOR simulation results. MELCOR are showing that an oxidational reaction starts a little bit earlier time and has the slightly higher value of the accumulated hydrogen mass, while COMPASS code predicts the slightly lower value of the accumulated hydrogen mass.

  9. SIMULATED ANIMAL EXPERIMENTS IN TEACHING AND RESEARCH

    Directory of Open Access Journals (Sweden)

    Chirag B. Mistry, Shreya M. Shah, Jagatkumar D. Bhatt

    2015-07-01

    Full Text Available Animal experiments are of paramount importance in the pre-clinical screening of new chemical entity. On the other hand, various regulatory guidelines for animal experiments are becoming more stringent in the face of worldwide protests by animal rights activists. Moreover, simulated animal experiments’ softwares are being developed and they can be implemented in the postgraduate and graduate students’ curriculum for demonstration of standard physiological and pharmacological principles compared to real time animal experiments. In fact, implementation of virtual experiment will decrease hand on experience of animal experiments among medical students, but after medical graduation, animal experiment is lest utilized during their day to day clinical practice. Similarly, in case of postgraduate pharmacology curriculum, computer based virtual animal experiments can facilitate teaching and learning in a short span of time with various protocols, without sacrificing any animal for already established experimental outcomes.

  10. Screening Experiments for Simulation: A Review

    OpenAIRE

    Kleijnen, J.P.C.

    2007-01-01

    This article reviews so-called screening in simulation; i.e., it examines the search for the really important factors in experiments with simulation models that have very many factors (or inputs). The article focuses on a most efficient and effec- tive screening method, namely Sequential Bifurcation. It ends with a discussion of possible topics for future research, and forty references for further study.

  11. Simulations for the Frankfurt Funneling Experiment

    CERN Document Server

    Thibus, Jan

    2005-01-01

    Beam simulations for the Frankfurt Funneling Experiment are done with RFQSim and FUSIONS. RFQSim is a particle dynamic program to compute macro particle bunches in the 6D phase space through a RFQ accelerator. Behind the RFQ the simulation software FUSIONS calculates both beam lines through a r.f. funneling deflector. To optimise beam transport of existing and new funneling deflector structures FUSIONS is presently being developed. The status of the development of FUSIONS and the results will be presented.

  12. A simulation program for the VIRGO experiment

    International Nuclear Information System (INIS)

    Caron, B.; Dominjon, A.; Flaminio, R.; Marion, F.; Massonet, L.; Morand, R.; Mours, B.; Verkindt, D.; Yvert, M.

    1994-07-01

    Within the VIRGO experiment a simulation program is developed providing an accurate description of the interferometric antenna behaviour, taking into account all sources of noise. Besides its future use as a tool for data analysis and for the commissioning of the apparatus, the simulation helps finalizing the design of the detector. Emphasis is put at the present time on the study of the stability of optical components implied in the global feedback control system of the interferometer. (author). 5 refs., 4 figs

  13. Erosion products in disruption simulation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Safronov, V.; Arkhipov, N.; Bakhtin, V.; Barsuk, V.; Kurkin, S.; Mironova, E.; Toporkov, D.; Vasenin, S.; Zhitlukhin, A. [Troitsk Inst. for Innovation and Fusion Research, Troisk, Moscow region (Russian Federation); Arkhipov, I. [Inst. of Physical Chemistry, Russian Academy of Science, Moscow (Russian Federation); Werle, H.; Wuerz, H. [Forschungszentrum Karlsruhe (Germany)

    1998-07-01

    Erosion of divertor materials under tokamak disruption event presents a serious problem of ITER technology. Erosion restricts the divertor lifetime and leads to production of redeposited layers of the material retaining large amount of tritium, which is a major safety issue for future fusion reactor. Since ITER disruptive heatloads are not achievable in existing tokamaks, material erosion is studied in special simulation experiments. Till now the simulation experiments have focused mainly on investigation of shielding effect and measurement of erosion rate. In the present work the properties of eroded and redeposited graphite are studied under condition typical for hard ITER disruption. (author)

  14. Simulations of the DAXUMM and DAX Experiments

    Science.gov (United States)

    Sutherland, Gerrit; Biss, Matthew

    2017-06-01

    The U.S. Army Research Laboratory uses small-scale experiments to determine explosive properties (detonation pressure and velocity) using a minimal amount of material. The disk acceleration experiment (DAX) uses an end detonated cylindrical explosive charge in which a velocity of a thin metal plate affixed to the opposing end is measured with a photonic Doppler velocimeter. In contrast, the disk acceleration experiment utilizing minimal material (DAXUMM) uses a centrally detonated mostly spherical charge with a flat region formed on the sphere. Like the DAX, a thin metal plate is affixed to the flat region. From methods of Lorenz and Biss features of the velocity records can be used to determine detonation pressure and velocities. Simulations are presented that show the following. First, simulations predict the differences in the plate velocity histories between the two configurations and will be compared to experiments. Second, the simulations predict the response of each test if a non-ideal explosive (large reaction zone) is used. The presence of a large reaction zone is speculated to affect the velocity histories. Finally, the simulations will predict the effect of unfilled or filled voids (mineral oil) adjacent to the metal plate. Such voids are speculated to be present during some experiments and to have altered results.

  15. MHD simulation of plasma compression experiments

    Science.gov (United States)

    Reynolds, Meritt; Barsky, Sandra; de Vietien, Peter

    2017-10-01

    General Fusion (GF) is working to build 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 plasmas formed by coaxial helicity injection in a series of experiments called PCS (Plasma Compression, Small). We simulate the PCS experiments using the finite-volume MHD code VAC. The single-fluid plasma model includes temperature-dependent resistivity and anisotropic heat transport. The time-dependent curvilinear mesh for MHD simulation is derived from LS-DYNA simulations of actual field tests of liner implosion. We will discuss how 3D simulations reproduced instability observed in the PCS13 experiment and correctly predicted stabilization of PCS14 by ramping the shaft current during compression. We will also present a comparison of simulated Mirnov and x-ray diagnostics with experimental measurements indicating that PCS14 compressed well to a linear compression ratio of 2.5:1.

  16. Pattern recognition model to estimate intergranular stress corrosion cracking (IGSCC) at crevices and pit sites of 304 SS in BWR environments

    International Nuclear Information System (INIS)

    Urquidi-Macdonald, Mirna

    2004-01-01

    Many publications have shown that crack growth rates (CGR) due to intergranular stress corrosion cracking (IGSCC) of metals is dependent on many parameters related to the manufacturing process of the steel and the environment to which the steel is exposed. Those parameters include, but are not restricted to, the concentration of chloride, fluoride, nitrates, and sulfates, pH, fluid velocity, electrochemical potential (ECP), electrolyte conductivity, stress and sensitization applied to the steel during its production and use. It is not well established how combinations of each of these parameters impact the CGR. Many different models and beliefs have been published, resulting in predictions that sometimes disagree with experimental observations. To some extent, the models are the closest to the nature of IGSCC, however, there is not a model that fully describes the entire range of observations, due to the difficulty of the problem. Among the models, the Fracture Environment Model, developed by Macdonald et al., is the most physico-chemical model, accounting for experimental observations in a wide range of environments or ECPs. In this work, we collected experimental data on BWR environments and designed a data mining pattern recognition model to learn from that data. The model was used to generate CGR estimations as a function of ECP on a BWR environment. The results of the predictive model were compared to the Fracture Environment Model predictions. The results from those two models are very close to the experimental observations of the area corresponding to creep and IGSCC controlled by diffusion. At more negative ECPs than the potential corresponding to creep, the pattern recognition predicts an increase of CGR with decreasing ECP, while the Fracture Environment Model predicts the opposite. The results of this comparison confirm that the pattern recognition model covers 3 phenomena: hydrogen embrittlement at very negative ECP, creep at intermediate ECP, and IGSCC

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

    Science.gov (United States)

    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.

  18. Experience with simulator training for emergency conditions

    International Nuclear Information System (INIS)

    1987-12-01

    The training of operators by the use of simulators is common to most countries with nuclear power plants. Simulator training programmes are generally well developed, but their value can be limited by the age, type, size and capability of the simulator. Within these limits, most full scope simulators have a capability of training operators for a range of design basis accidents. It is recognized that human performance under accident conditions is difficult to predict or analyse, particularly in the area of severe accidents. These are rare events and by their very nature, unpredictable. Of importance, therefore, is to investigate the training of operators for severe accident conditions, and to examine ways in which simulators may be used in this task. The International Nuclear Safety Advisory Group (INSAG) has reviewed this field and the associated elements of human behaviour. It has recommended that activities are concentrated on this area. Initially it is encouraging the following objectives: i) To train operators for accident conditions including severe accidents and to strongly encourage the development and use of simulators for this purpose; ii) To improve the man-machine interface by the use of computer aids to the operator; iii) To develop human performance requirements for plant operating staff. As part of this work, the IAEA convened a technical committee on 15-19 September 1986 to review the experience with simulator training for emergency conditions, to review simulator modelling for severe accident training, to examine the role of human cognitive behaviour modelling, and to review guidance on accident scenarios. A substantial deviation may be a major fuel failure, a Loss of Coolant Accident (LOCA), etc. Examples of engineered safety features are: an Emergency Core Cooling System (ECCS), and Containment Systems. This report was prepared by the participants during the meeting and reviewed further in a Consultant's Meeting. It also includes papers which were

  19. Guiding Simulations and Experiments using Continuation

    DEFF Research Database (Denmark)

    When applying continuation of periodic solutions to high-dimensional finite element models one might face a dilemma. The mesh resolution and thus the dimension N of the model are typically chosen such that a given computer system can store the information necessary to perform one integration step...... for dimension N, but not for larger dimensions. In other words, a model is usually implemented as a carefully derived implicit integration scheme tailored for numerically stable simulations with the highest spacial resolution admitted by the computational power available. On the other hand, stable numerical...... developed method of control based continuation allows the continuation of periodic solutions without a reduction of the model resolution, and even directly in physical experiments. Moreover, both a simulation as well as an experiment can run asynchronously from the actual continuation method, which...

  20. Experiments and Numerical Simulations of Electrodynamic Tether

    Science.gov (United States)

    Iki, Kentaro; Kawamoto, Satomi; Takahashi, Ayaka; Ishimoto, Tomori; Yanagida, Atsushi; Toda, Susumu

    As an effective means of suppressing space debris growth, the Aerospace Research and Development Directorate of the Japan Aerospace Exploration Agency (JAXA) has been investigating an active space debris removal system that employs highly efficient electrodynamic tether (EDT) technology for orbital transfer. This study investigates tether deployment dynamics by means of on-ground experiments and numerical simulations of an electrodynamic tether system. Some key parameters used in the numerical simulations, such as the elastic modulus and damping ratio of the tether, the spring constant of the coiling of the tether, and deployment friction, must be estimated, and various experiments are conducted to determine these values. As a result, the following values were obtained: The elastic modulus of the tether was 40 GPa, and the damping ratio of the tether was 0.02. The spring constant and the damping ratio of the tether coiling were 10-4 N/m and 0.025 respectively. The deployment friction was 0.038ν + 0.005 N. In numerical simulations using a multiple mass tether model, tethers with lengths of several kilometers are deployed and the attitude dynamics of satellites attached to the end of the tether and tether libration are calculated. As a result, the simulations confirmed successful deployment of the tether with a length of 500 m using the electrodynamic tether system.

  1. Experiments and DEM Simulations of Granular Ratcheting

    OpenAIRE

    Zorzi Gianluca; Artoni Riccardo; Gabrieli Fabio

    2017-01-01

    In this work we studied the effect of cyclic loading on a granular packing by means of numerical simulations and experiments. A confined packing of glass beads was prepared and one of the walls was moved cyclically with a prescribed amplitude of the order of the particle diameter. Different amplitudes were tested, and their effect on the free surface evolution, the force transmitted to the moving wall and the displacement patterns in the material was characterized. Discrete numerical simulati...

  2. Simulation of the Phebus FPT1 experiment

    International Nuclear Information System (INIS)

    Amador G, R.; Nunez C, A.; Angel M, E. Del

    2003-01-01

    The present work describes the pattern of the denominated installation Phebus developed and used by the National Commission of Nuclear Security and Safeguards for their participation in the International Standard Problem ISP-46, organized by the Nuclear Energy Agency (NEA). The exercise consisted on the simulation of the denominated experiment Phebus FPT1 carried out in the experimental installation Phebus located in the Institut de Protection et de Surete Nucleaire of France. The experiment Phebus FP1 had as objective to evaluate the capacity of different computer codes to model in integral form the physical processes that are carried out during a severe accident in a pressurized water reactor (PWR), from the degradation of the core until the late stage with the formation of a pool of fused material, hydrogen production, liberation and transport of fission products, phenomena in the contention and chemistry of the iodine. The CNSNS uses the version bi of the SCDAPSIM code developed by the company Innovative Software Systems to simulate the International Standard Problem 46. The obtained results showed that the code is able to predict the thermohydraulic part of the experiment, however the same thing doesn't happen to the parameters related with the one fused of the fuel. (Author)

  3. A second simulated criticality accident dosimetry experiment

    CERN Document Server

    Adams, N

    1973-01-01

    This experiment was undertaken to facilitate training in criticality dose assessment by UKAEA and BNFL establishments with potential criticality hazards. Personal dosemeters, coins, samples of hair, etc. supplied by the seven participating establishments were attached to a man-phantom filled with a solution of sodium nitrate (simulating 'body-sodium'), and exposed to a burst of radiation from the AWRE pulsed reactor VIPER. The neutron and photon doses were each several hundred rads. Participants made two sets of dose assessments. The first, made solely from the evidence of their routine dosemeters the activation of body-sodium and standard monitoring data, simulated the initial dose assessment that would be made before the circumstances of a real incident were established. The second was made when the position and orientation of the phantom relative to the reactor and the shielding (20 cm of copper) between the reactor core and the phantom were disclosed. Neutron and photon dose assessments for comparison wit...

  4. Simulation experiments and solar wind sputtering

    International Nuclear Information System (INIS)

    Griffith, J.E.; Papanastassiou, D.A.; Russell, W.A.; Tombrello, T.A.; Weller, R.A.

    1978-01-01

    In order to isolate the role played by solar wind sputtering from other lunar surface phenomena a number of simulation experiments were performed, including isotope abundance measurements of Ca sputtered from terrestrial fluorite and plagioclase by 50-keV and 130-keV 14 N beams, measurement of the energy distribution of U atoms sputtered with 80-keV 40 Ar, and measurement of the fraction of sputtered U atoms which stick on the surfaces used to collect these atoms. 10 references

  5. Simulation of a complete inelastic neutron scattering experiment

    DEFF Research Database (Denmark)

    Edwards, H.; Lefmann, K.; Lake, B.

    2002-01-01

    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...

  6. Plasma temperature measurements in disruption simulated experiment

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, N.I. [Troitsk Inst. for Innovation and Fusion Research (Russian Federation); Bakhtin, V.P. [Troitsk Inst. for Innovation and Fusion Research (Russian Federation); Safronov, V.M. [Troitsk Inst. for Innovation and Fusion Research (Russian Federation); Toporkov, D.A. [Troitsk Inst. for Innovation and Fusion Research (Russian Federation); Vasenin, S.G. [Troitsk Inst. for Innovation and Fusion Research (Russian Federation); Wurz, H. [Kernforschungszentrum Karlsruhe, INR (Germany); Zhitlukhin, A.M. [Troitsk Inst. for Innovation and Fusion Research (Russian Federation)

    1995-12-31

    Results are reported of experiments to measure the temporal and spatial distributions of a temperature and radiation of a near surface plasma cloud appearing in the disruption simulated experiments. These measurements are needed to verificate the different numerical models of vapor shielding layer which appears to arise near the divertor plates surface and prevents them from the bulk of the incoming energy. Experiments with graphite and tungsten samples were carried out at the 2MK-200 plasma facility. Long CUSP trap was used as a source of high temperature deuterium plasma with a power density W = 10 MW/cm{sup 2} and time duration t = 20 mcs. Laser scattering, space and time resolved soft x-ray spectroscopy was employed to measure the plasma cloud temperature and radiation. The different behaviour of shielding layer parameters was shown for a graphite and tungsten samples. For a tungsten the sharp boundary existed between the incoming deuterium plasma and the thin layer of ablated material plasma and the strong gradient of electron temperature took place in this zone. For a graphite this boundary was broadened at the distance and the main part of the screening layer consisted of the mixture of the incoming deuterium and ablated carbon plasma. (orig.).

  7. Designing solar thermal experiments based on simulation

    International Nuclear Information System (INIS)

    Huleihil, Mahmoud; Mazor, Gedalya

    2013-01-01

    In this study three different models to describe the temperature distribution inside a cylindrical solid body subjected to high solar irradiation were examined, beginning with the simpler approach, which is the single dimension lump system (time), progressing through the two-dimensional distributed system approach (time and vertical direction), and ending with the three-dimensional distributed system approach with azimuthally symmetry (time, vertical direction, and radial direction). The three models were introduced and solved analytically and numerically. The importance of the models and their solution was addressed. The simulations based on them might be considered as a powerful tool in designing experiments, as they make it possible to estimate the different effects of the parameters involved in these models

  8. Amorphous nanoparticles — Experiments and computer simulations

    International Nuclear Information System (INIS)

    Hoang, Vo Van; Ganguli, Dibyendu

    2012-01-01

    The data obtained by both experiments and computer simulations concerning the amorphous nanoparticles for decades including methods of synthesis, characterization, structural properties, atomic mechanism of a glass formation in nanoparticles, crystallization of the amorphous nanoparticles, physico-chemical properties (i.e. catalytic, optical, thermodynamic, magnetic, bioactivity and other properties) and various applications in science and technology have been reviewed. Amorphous nanoparticles coated with different surfactants are also reviewed as an extension in this direction. Much attention is paid to the pressure-induced polyamorphism of the amorphous nanoparticles or amorphization of the nanocrystalline counterparts. We also introduce here nanocomposites and nanofluids containing amorphous nanoparticles. Overall, amorphous nanoparticles exhibit a disordered structure different from that of corresponding bulks or from that of the nanocrystalline counterparts. Therefore, amorphous nanoparticles can have unique physico-chemical properties differed from those of the crystalline counterparts leading to their potential applications in science and technology.

  9. Experiments and DEM Simulations of Granular Ratcheting

    Directory of Open Access Journals (Sweden)

    Zorzi Gianluca

    2017-01-01

    Full Text Available In this work we studied the effect of cyclic loading on a granular packing by means of numerical simulations and experiments. A confined packing of glass beads was prepared and one of the walls was moved cyclically with a prescribed amplitude of the order of the particle diameter. Different amplitudes were tested, and their effect on the free surface evolution, the force transmitted to the moving wall and the displacement patterns in the material was characterized. Discrete numerical simulations were also carried out with the specific purpose of evaluating the effect of the particle shape on the dynamics of the system. The displacement amplitude of the moving wall was shown to increase the maximum force experienced at the end of the compressive phase of the wall movement; the angularity of the particles had a similar effect. Force-wall displacement curves displayed a peculiar hysteretic behavior. The evolution of the system towards an asymptotic state was shown to be faster for spheres than for angular particles; the latter displayed an interesting long-time evolution of the force-displacement paths which deserves deeper investigations.

  10. Experiments and DEM Simulations of Granular Ratcheting

    Science.gov (United States)

    Zorzi, Gianluca; Artoni, Riccardo; Gabrieli, Fabio

    2017-06-01

    In this work we studied the effect of cyclic loading on a granular packing by means of numerical simulations and experiments. A confined packing of glass beads was prepared and one of the walls was moved cyclically with a prescribed amplitude of the order of the particle diameter. Different amplitudes were tested, and their effect on the free surface evolution, the force transmitted to the moving wall and the displacement patterns in the material was characterized. Discrete numerical simulations were also carried out with the specific purpose of evaluating the effect of the particle shape on the dynamics of the system. The displacement amplitude of the moving wall was shown to increase the maximum force experienced at the end of the compressive phase of the wall movement; the angularity of the particles had a similar effect. Force-wall displacement curves displayed a peculiar hysteretic behavior. The evolution of the system towards an asymptotic state was shown to be faster for spheres than for angular particles; the latter displayed an interesting long-time evolution of the force-displacement paths which deserves deeper investigations.

  11. Background simulation for the COBRA-experiment

    Energy Technology Data Exchange (ETDEWEB)

    Quante, Thomas [TU Dortmund, Institut fuer Physik (Germany); Collaboration: COBRA-Collaboration

    2015-07-01

    COBRA is a next-generation experiment searching for neutrinoless double beta (0νββ) decay using CdZnTe semiconductor detectors. The main focus is on {sup 116}Cd, with a Q-value of 2813.5 keV well above the highest dominant naturally occurring gamma lines. By measuring the half-life of the 0νββ decay, it is possible to clarify the nature of the neutrino as either Dirac or Majorana particle and furthermore to determine the effective Majorana mass. COBRA is currently in the demonstrator phase to study possible background contributions and gain information about the longterm stability of the used detectors. For this purpose a demonstrator array made up of 64 Cadmium-Zinc-Telluride (CdZnTe) semiconductor detectors in coplanar grid configuration was designed and realised at the Gran Sasso Underground laboratory (LNGS) in Italy. Simulations of the whole demonstrator setup are ongoing to reproduce the measured spectra for each detector. This is done in two steps. The first uses the Geant4 based framework VENOM for tracking and energy deposition inside each detector. Detector effects like the energy resolution and electron trapping have to be applied in the second step. The used detector geometry has to be verified against calibration measurements. This talk gives an overview of the current simulation status.

  12. Herbicide Persistence in Seawater Simulation Experiments.

    Directory of Open Access Journals (Sweden)

    Philip Mercurio

    Full Text Available 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

  13. Herbicide Persistence in Seawater Simulation Experiments

    Science.gov (United States)

    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

  14. Augmented Visual Experience of Simulated Solar Phenomena

    Science.gov (United States)

    Tucker, A. O., IV; Berardino, R. A.; Hahne, D.; Schreurs, B.; Fox, N. J.; Raouafi, N.

    2017-12-01

    The Parker Solar Probe (PSP) mission will explore the Sun's corona, studying solar wind, flares and coronal mass ejections. The effects of these phenomena can impact the technology that we use in ways that are not readily apparent, including affecting satellite communications and power grids. Determining the structure and dynamics of corona magnetic fields, tracing the flow of energy that heats the corona, and exploring dusty plasma near the Sun to understand its influence on solar wind and energetic particle formation requires a suite of sensors on board the PSP spacecraft that are engineered to observe specific phenomena. Using models of these sensors and simulated observational data, we can visualize what the PSP spacecraft will "see" during its multiple passes around the Sun. Augmented reality (AR) technologies enable convenient user access to massive data sets. We are developing an application that allows users to experience environmental data from the point of view of the PSP spacecraft in AR using the Microsoft HoloLens. Observational data, including imagery, magnetism, temperature, and density are visualized in 4D within the user's immediate environment. Our application provides an educational tool for comprehending the complex relationships of observational data, which aids in our understanding of the Sun.

  15. Effective assimilation of global precipitation: simulation experiments

    Directory of Open Access Journals (Sweden)

    Guo-Yuan Lien

    2013-07-01

    Full Text Available Past attempts to assimilate precipitation by nudging or variational methods have succeeded in forcing the model precipitation to be close to the observed values. However, the model forecasts tend to lose their additional skill after a few forecast hours. In this study, a local ensemble transform Kalman filter (LETKF is used to effectively assimilate precipitation by allowing ensemble members with better precipitation to receive higher weights in the analysis. In addition, two other changes in the precipitation assimilation process are found to alleviate the problems related to the non-Gaussianity of the precipitation variable: (a transform the precipitation variable into a Gaussian distribution based on its climatological distribution (an approach that could also be used in the assimilation of other non-Gaussian observations and (b only assimilate precipitation at the location where at least some ensemble members have precipitation. Unlike many current approaches, both positive and zero rain observations are assimilated effectively. Observing system simulation experiments (OSSEs are conducted using the Simplified Parametrisations, primitivE-Equation DYnamics (SPEEDY model, a simplified but realistic general circulation model. When uniformly and globally distributed observations of precipitation are assimilated in addition to rawinsonde observations, both the analyses and the medium-range forecasts of all model variables, including precipitation, are significantly improved as compared to only assimilating rawinsonde observations. The effect of precipitation assimilation on the analyses is retained on the medium-range forecasts and is larger in the Southern Hemisphere (SH than that in the Northern Hemisphere (NH because the NH analyses are already made more accurate by the denser rawinsonde stations. These improvements are much reduced when only the moisture field is modified by the precipitation observations. Both the Gaussian transformation and

  16. Simulation of a complete inelastic neutron scattering experiment

    CERN Document Server

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

    2002-01-01

    A simulation of an inelastic neutron scattering experiment on the high-temperature superconductor La sub 2 sub - sub x Sr sub x CuO sub 4 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. (orig.)

  17. Simulation of Stochastic Loads for Fatigue Experiments

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Brincker, Rune

    1989-01-01

    A simple direct simulation method for stochastic fatigue-load generation is described in this paper. The simulation method is based on the assumption that only the peaks of the load process significantly affect the fatigue life. The method requires the conditional distribution functions of load...... ranges given the last peak values. Analytical estimates of these distribution functions are presented in the paper and compared with estimates based on a more accurate simulation method. In the more accurate simulation method samples at equidistant times are generated by approximating the stochastic load...... process by a Markov process. Two different spectra from two tubular joints in an offshore structure (one narrow banded and one wide banded) are considered in an example. The results show that the simple direct method is quite efficient and results in a simulation speed of about 3000 load cycles per second...

  18. Simulation of Stochastic Loads for Fatigue Experiments

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Brincker, Rune

    1989-01-01

    process by a Markov process. Two different spectra from two tubular joints in an offshore structure (one narrow banded and one wide banded) are considered in an example. The results show that the simple direct method is quite efficient and results in a simulation speed of about 3000 load cycles per second......A simple direct simulation method for stochastic fatigue-load generation is described in this paper. The simulation method is based on the assumption that only the peaks of the load process significantly affect the fatigue life. The method requires the conditional distribution functions of load...... ranges given the last peak values. Analytical estimates of these distribution functions are presented in the paper and compared with estimates based on a more accurate simulation method. In the more accurate simulation method samples at equidistant times are generated by approximating the stochastic load...

  19. Simulation of Stochastic Loads for Fatigue Experiments

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Brincker, Rune

    process by a Markov process. Two different spectra from two tubular joints in an offshore structure (one narrow banded and one wide banded) are considered in an example. The results show that the simple direct method is quite efficient and is results in a simulation speed at about 3000 load cycles per......A simple direct simulation method for stochastic fatigue load generation is described in this paper. The simulation method is based on the assumption that only the peaks of the load process significantly affect the fatigue life. The method requires the conditional distribution functions of load...... ranges given the last peak values. Analytical estimates of these distribution functions are presented in the paper and compared with estimates based on a more accurate simulation method. In the more accurate simulation method samples at equidistant times are generated by approximating the stochastic load...

  20. Experiment Simulation Configurations Used in DUNE CDR

    Energy Technology Data Exchange (ETDEWEB)

    Alion, T. [Univ. of South Carolina, Columbia, SC (United States); Black, J. J. [Univ. of Warwick, Coventry (United Kingdom); Bashyal, A. [Oregon State Univ., Corvallis, OR (United States); Bass, M. [Univ. of Oxford (United Kingdom); Bishai, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cherdack, D. [Colorado State Univ., Fort Collins, CO (United States); Diwan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Djurcic, Z. [Argonne National Lab. (ANL), Argonne, IL (United States); Evans, J. [Univ. of Manchester (United Kingdom); Fernandez-Martinez, E. [Madrid Autonama Univ. (Spain); Fields, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Fleming, B. [Yale Univ., New Haven, CT (United States); Gran, R. [Univ. of Minnesota, Duluth, MN (United States); Guenette, R. [Univ. of Oxford (United Kingdom); Hewes, J. [Univ. of Manchester (United Kingdom); Hogan, M. [Colorado State Univ., Fort Collins, CO (United States); Hylen, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Junk, T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kohn, S. [Univ. of California, Berkeley, CA (United States); LeBrun, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lundberg, B. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Marchionni, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Morris, C. [Univ. of California, Berkeley, CA (United States); Papadimitriou, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rameika, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rucinski, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Soldner-Rembold, S. [Univ. of Manchester (United Kingdom); Sorel, M. [Spanish National Research Council (CSIC), Valencia (Spain). Univ. of Valencia (UV), Inst. de Fisica Corpuscular; Urheim, J. [Indiana Univ., Bloomington, IN (United States); Viren, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Whitehead, L. [Univ. of Houston, TX (United States); Wilson, R. [Colorado State Univ., Fort Collins, CO (United States); Worcester, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zeller, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-06-30

    The LBNF/DUNE CDR describes the proposed physics program and experimental design at the conceptual design phase. Volume 2, entitled The Physics Program for DUNE at LBNF, outlines the scientific objectives and describes the physics studies that the DUNE collaboration will perform to address these objectives. The long-baseline physics sensitivity calculations presented in the DUNE CDR rely upon simulation of the neutrino beam line, simulation of neutrino interactions in the far detector, and a parameterized analysis of detector performance and systematic uncertainty. The purpose of this posting is to provide the results of these simulations to the community to facilitate phenomenological studies of long-baseline oscillation at LBNF/DUNE. Additionally, this posting includes GDML of the DUNE single-phase far detector for use in simulations. DUNE welcomes those interested in performing this work as members of the collaboration, but also recognizes the benefit of making these configurations readily available to the wider community.

  1. Simulation of containment atmosphere stratification experiment using local instantaneous description

    International Nuclear Information System (INIS)

    Babic, M.; Kljenak, I.

    2004-01-01

    An experiment on mixing and stratification in the atmosphere of a nuclear power plant containment at accident conditions was simulated with the CFD code CFX4.4. The original experiment was performed in the TOSQAN experimental facility. Simulated nonhomogeneous temperature, species concentration and velocity fields are compared to experimental results. (author)

  2. Factor screening in simulation experiments : Review of sequential bifurcation

    NARCIS (Netherlands)

    Kleijnen, Jack P.C.; Axelopoulos, C.; Goldsman, D.; Wilson, J.R.

    2009-01-01

    Factor screening means searching for the most important factors (or inputs) among the many factors that may be varied in an experiment with a real or a simulated system. This chapter gives a review of Sequential Bifurcation (SB), which is a screening method for simulation experiments in which many

  3. Simulation Strategies for the ATLAS Experiment at LHC

    CERN Document Server

    Rimoldi, A; The ATLAS collaboration

    2011-01-01

    The ATLAS experiment, operational at the new LHC collider, is fully simulated using the Geant4 tool. The simulation program has been built within the ATLAS common framework Athena. The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for large-scale production of events on the LHC Computing Grid. This simulation requires many components, from the generators that simulate particle collisions, through packages simulating the response of the various detectors and triggers. All of these components come together under the ATLAS simulation infrastructure. The latest developments went into the direction to better represent the reality of the detector in all the possible details. The latest developments provide increased functionality and robustness. The full process is constantly monitored and profiled. Increased performance guarantee the best use of available resources without any degradation in the quality and accuracy of the simulation itself. In the presentation emphasis is...

  4. EBW simulation for MAST and NSTX experiments

    International Nuclear Information System (INIS)

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

    2005-01-01

    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

  5. 3D Coulomb balls: experiment and simulation

    International Nuclear Information System (INIS)

    Arp, O; Block, D; Bonitz, M; Fehske, H; Golubnychiy, V; Kosse, S; Ludwig, P; Melzer, A; Piel, A

    2005-01-01

    Spherically symmetric three-dimensional charged particle clusters are analyzed experimentally and theoretically. Based on accurate molecular dynamics simulations ground state configurations and energies with clusters for N ≤ 160 are presented which correct previous results of Hasse and Avilov [Phys. Rev. A 44, 4506 (1991)]. A complete table is given in the appendix. Further, the lowest metastable states are analyzed

  6. Dynamic System Simulation of the KRUSTY Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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.

  7. Comparison of laboratory and field experience of PWSCC in Alloy 182 weld metal

    Energy Technology Data Exchange (ETDEWEB)

    Scott, P.; Meunier, M.-C.; Steltzlen, F. [AREVA NP, Tour AREVA, Paris La Defense (France); Calonne, O.; Foucault, M. [AREVA NP, Centre Technique, Le Creusot Cedex (France); Combrade, P. [ACXCOR, Saint Etienne (France); Amzallag, C. [EDF, SEPTEN, Villeurbanne (France)

    2007-07-01

    Laboratory studies of stress corrosion cracking of the nickel base weld metal, Alloy 182, in simulated PWR primary water suggest similar resistance to crack initiation and somewhat enhanced propagation rates relative to wrought Alloy 600. By contrast, field experience of cracking in the primary circuits of PWRs shows in general much better performance for Alloy 182 relative to Alloy 600 than would be anticipated from laboratory studies. This paper endeavours to resolve this apparent conundrum. It draws on the conclusions of recent research that has focussed on the role of surface finish, particularly cold work and residual stresses resulting from different fabrication processes, on the risk of initiating IGSCC in nickel base alloys in PWR primary water. It also draws on field experience of stress corrosion cracking that highlights the important role of surface finish for crack initiation. (author)

  8. Experiences on dynamic simulation software in chemical engineering education

    DEFF Research Database (Denmark)

    Komulainen, Tiina M.; Enemark-rasmussen, Rasmus; Sin, Gürkan

    2012-01-01

    Commercial process simulators are increasing interest in the chemical engineer education. In this paper, the use of commercial dynamic simulation software, D-SPICE® and K-Spice®, for three different chemical engineering courses is described and discussed. The courses cover the following topics......: basic chemical engineering, operability and safety analysis and process control. User experiences from both teachers and students are presented. The benefits of dynamic simulation as an additional teaching tool are discussed and summarized. The experiences confirm that commercial dynamic simulators...

  9. Rolling motion: experiments and simulations focusing on sliding friction forces

    International Nuclear Information System (INIS)

    Onorato, P.; Malgieri, M.; De Ambrosis, A.

    2015-01-01

    The paper presents an activity sequence aimed at elucidating the role of sliding friction forces in determining/shaping the rolling motion. The sequence is based on experiments and computer simulations and it is devoted both to high school and undergraduate students. Measurements are carried out by using the open source Tracker Video Analysis software, while interactive simulations are realized by means of Algodoo, a freeware 2D-simulation software. Data collected from questionnaires before and after the activities, and from final reports, show the effectiveness of combining simulations and Video Based Analysis experiments in improving students’ understanding of rolling motion.

  10. Nursing students' experiences with high-fidelity simulation.

    Science.gov (United States)

    Najjar, Rana Halabi; Lyman, Bret; Miehl, Nick

    2015-03-19

    Research has revealed the effectiveness of simulation for facilitating student development of self-efficacy, knowledge, clinical judgment, and proficiency in technical skills. This grounded theory study was conducted to describe the experience of nursing students in high-fidelity simulation and develop a model which explicates the experience of nursing students in simulation. Focus group interviews were conducted with three cohorts of students enrolled in a baccalaureate nursing program who experienced simulation four to twelve times per academic year. Five prominent themes emerged during analysis Emotional Processing; Anxiety; Making Connections; Fidelity; and Learning. The Simulation Learning Model - Student Experience (SLM-SE) was developed to illustrate the student's multi-dimensional experience of learning through high-fidelity simulation. Findings from this study suggest that students are better equipped to learn through increasing confidence and experience, continued reflection-on action and enhanced peer-to-peer interaction. Recommendations for future research include developing strategies to optimize students' experiences for learning in simulation.

  11. Stress Corrosion Crack Growth of Alloy 52M in Simulated PWR Primary Water

    Science.gov (United States)

    Toloczko, M. B.; Olszta, M. J.; Bruemmer, S. M.

    Crack-growth experiments have been performed on five different alloy 52M welds in simulated PWR primary water at 350°C or 360°C. The alloy 52M test matrix included V-groove and narrow-gap welds, an overlay on alloy 182, and an inlay on alloy 82. For the overlay and inlay materials, crack growth rates are reported only on the alloy 52M weld well beyond the dilution zone. In one of the narrow gap welds, the crack path was oriented to pass through a distribution of pre-existing weld cracks and their influence on stress-corrosion behavior is evaluated. Intergranular stress corrosion cracking (IGSCC) is observed in several alloy 52M welds, however propagation rates remain below 5x10-9 mm/s in all cases. Comparisons will be made to our previous SCC measurements on alloy 152 and 52 welds.

  12. The simulation for the ATLAS experiment Present status and outlook

    CERN Document Server

    Rimoldi, A; Gallas, M; Nairz, A; Boudreau, J; Tsulaia, V; Costanzo, D

    2004-01-01

    The simulation program for the ATLAS experiment is presently operational in a full OO environment. This important physics application has been successfully integrated into ATLAS's common analysis framework, ATHENA. In the last year, following a well stated strategy of transition from a GEANT3 to a GEANT4-based simulation, a careful validation programme confirmed the reliability, performance and robustness of this new tool, as well as its consistency with the results of previous simulation. Generation, simulation and digitization steps on different sets of full physics events we retested for performance. The same software used to simulate the full the ATLAS detector is also used with testbeam configurations. Comparisons to real data in the testbeam validate both the detector description and the physics processes within each subcomponent. In this paper we present the current status of ATLAS GEANT4 simulation, describe the functionality tests performed during its validation phase, and the experience with distrib...

  13. Finite element simulation of exfoliation experiments

    International Nuclear Information System (INIS)

    Nutt, G.L.

    1992-01-01

    We previously reported bond strength measurements of metal/ceramic interfaces using shock waves to separate the bond by spallation. The technique relies on interpretation of the free surface velocity of a metal film as it is spalled from its substrate. A number of questions have been raised concerning the details of the interaction of the shock and interface. We provide answers by numerically modeling the experiments. We rederive the relationship between the maximum stress at the bond interface and the free surface velocity of the metal overlayer. We compare the analytical result with numerical calculations based on less restrictive assumptions, thereby supporting the analysis. We illustrate important design considerations of the experiment with numerical calculation and in the process, evaluate the effect of the artificial damping on the numerical results

  14. Radioactive source simulation for half-life experiment

    International Nuclear Information System (INIS)

    Wanitsuksombut, Warapon; Decthyothin, Chanti

    1999-01-01

    A simulation of radioactivity decay by using programmable light source with a few minutes half-life is suggested. A photodiode with digital meter label in cps is use instead of radiation detector. Both light source and photodiode are installed in a black box to avoid surrounding room light. The simulation set can also demonstrate Inverse Square Law experiment of radiation penetration. (author)

  15. Radioactive source simulation for half-life experiment

    Energy Technology Data Exchange (ETDEWEB)

    Wanitsuksombut, Warapon; Decthyothin, Chanti [Office of Atomic Energy for Peace, Chatuchak, Bangkok (Thailand)

    1999-09-01

    A simulation of radioactivity decay by using programmable light source with a few minutes half-life is suggested. A photodiode with digital meter label in cps is use instead of radiation detector. Both light source and photodiode are installed in a black box to avoid surrounding room light. The simulation set can also demonstrate Inverse Square Law experiment of radiation penetration. (author)

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

    Science.gov (United States)

    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…

  17. Magnetic processes in astrophysics theory, simulations, experiments

    CERN Document Server

    Rüdiger, Günther; Hollerbach, Rainer

    2013-01-01

    In this work the authors draw upon their expertise in geophysical and astrophysical MHD to explore the motion of electrically conducting fluids, the so-called dynamo effect, and describe the similarities and differences between different magnetized objects. They also explain why magnetic fields are crucial to the formation of the stars, and discuss promising experiments currently being designed to investigate some of the relevant physics in the laboratory. This interdisciplinary approach will appeal to a wide audience in physics, astrophysics and geophysics. This second edition covers such add

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

    Science.gov (United States)

    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.

  19. INTERNATIONAL EXPERIENCE OF THE ECONOMIC SIMULATION SOFTWARE USAGE IN EDUCATION

    Directory of Open Access Journals (Sweden)

    Dmytro Antoniuk

    2016-03-01

    Full Text Available The article describes the research of foreign business simulation usage experience within courses of MBA programs, higher education institutions, as a part of scientific researches and also as a platform for competitions and championships. Development of the information and communication technologies that causes decrease of business simulation purchasing, development and support expenses, gives a chance to expect business simulations usage spreading and expanding to the other potential usage domains. Business simulation development and usage area dynamics enables to conduct tendencies analysis of the market and work out the hypothesis regarding potential new business simulations usage areas. Additionally, business simulation market leaders’ products and services development and adjustments observation is proved to be possible and necessary. Exact business simulations usage examples at the foreign higher education institutions and business schools are described. Systematization of the studied and described business simulations has been performed. Besides, business simulations are proved to be effective for complementing traditional teaching methods and supporting the different domain specialists’ economic competencies development. Foreign experience of the business simulation usage may help to build the basement for the implementation of this learning and scientific research tool at the educational and scientific institution in Ukraine

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

    Science.gov (United States)

    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.

  1. Transport simulations of ohmic ignition experiment: IGNITEX

    International Nuclear Information System (INIS)

    Uckan, N.A.; Howe, H.C.

    1987-12-01

    The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large, and anomalous radiation and alpha losses and/or other enhanced transport losses (eta/sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

  2. Transport simulations of ohmic ignition experiment: IGNITEX

    International Nuclear Information System (INIS)

    Uckan, N.A.; Howe, H.C.

    1987-01-01

    The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large (≤2), and anomalous radiation and alpha losses and/or other enhanced transport losses (/eta//sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters (aB 0 2 /q* /approximately/ IB 0 , etc.) are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

  3. Experiences with linear solvers for oil reservoir simulation problems

    Energy Technology Data Exchange (ETDEWEB)

    Joubert, W.; Janardhan, R. [Los Alamos National Lab., NM (United States); 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.

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

    Science.gov (United States)

    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.

  5. Simulations of the Ondine experiment with the solitude code

    International Nuclear Information System (INIS)

    Gouard, P.; Gardelle, J.

    1992-11-01

    A new version of the SOLITUDE code, including an axial magnetic field and a cylindrical waveguide, is presented. It allows to simulate the ONDINE experiment at CESTA and to study the effects and behaviour of an actual electron beam in a Free Electron Laser amplifier experiment

  6. Simulation of the Quench-06 experiment with Scdapsim

    International Nuclear Information System (INIS)

    Angel M, E. del; Nunez C, A.; Amador G, R.

    2003-01-01

    The present work describes the pattern of the called Quench installation developed and used by the National Commission of Nuclear Security and Safeguards (CNSNS) for their participation in the International Standard Problem 45 (ISP), organized by the Nuclear Energy Agency (NEA). The exercise consisted on the simulation of the denominated experiment Quench-06 carried out in the experimental installation Quench located in the Forschungszentrum laboratory in Karlsruhe, Germany. The experiment Quench-06 consisted on simulating the sudden and late injection of water in a fuel assemble for a pressurized reactor (PWR). The CNSNS uses the version bd of the SCDAPSIM code developed by the company Innovative Software Systems (ISS) to simulate this experiment. The obtained results showed that the code is able to predict the experiment partially when overestimating the hydrogen production and of the partial fused of some fuel pellets, but predicting correctly the damage in the shroud. (Author)

  7. Impact of detector simulation in particle physics collider experiments

    Science.gov (United States)

    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.

  8. Rationalization of foundry processes on the basis of simulation experiment

    Directory of Open Access Journals (Sweden)

    S. Kukla

    2008-10-01

    Full Text Available The paper presents results of research obtained on the basis of simulation experiment, whose aim was to analyze the performance of cast iron foundry. A simulation model of automobile industry foundry was made. The course of the following processes was analyzedin a computer model: preparation of liquid cast iron, forming and filling the moulds, cooling and stamping the castings, cleaning andfinishing treatment. The sheets of multi-criterion evaluation were prepared, where criteria and variants were assessed by meansof subjective point evaluation and fuzzy character evaluation. The paper presents an analysis example of finishing activities of castings realized in foundry on traditional machines and efficient presses and in cooperation. On the basis of reports from a simulation experiment information was achieved related to activities’ duration, load of accessible resources, the problems of storage and transport, bottle necks in the system and appearing queues in from of workplaces. The research used a universal modelling and simulation packet for productionsystems - ARENA.

  9. Rainfall simulation experiments in the Southwestern USA using the Walnut Gulch rainfall simulator

    Science.gov (United States)

    The dataset contains hydrological, erosion, vegetation, ground cover, and other supplementary information from 272 rainfall simulation experiments conducted on 23 semi-arid rangeland locations in Arizona and Nevada between 2002 and 2013. On 30% of the plots simulations were conducted up to five time...

  10. Full scope simulator commissioning and training experience at Cernavoda NPP

    International Nuclear Information System (INIS)

    Balan, M.

    2000-01-01

    The paper presents the experience gained during commissioning and the initial use of the CANDU training full-scope simulator for operation personnel at Cernavoda NPP. The full-scope simulator as an integral part of the training programs that take place in Cernavoda Nuclear Training Department (CNTD), is mainly used for the development of operational skills, knowledge and attitudes required to operate the plant in a safe and efficient manner. (author)

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

    Directory of Open Access Journals (Sweden)

    P. P. Crooker

    2008-09-01

    Full Text Available 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.

  12. Effectiveness of Integrated Simulation and Clinical Experiences Compared to Traditional Clinical Experiences for Nursing Students.

    Science.gov (United States)

    Curl, Eileen D; Smith, Sheila; Ann Chisholm, Le; McGee, Leah Anne; Das, Kumar

    2016-01-01

    The focus of this research study was the evaluation of the effectiveness of using high-fidelity simulations to replace 50 percent of traditional clinical experiences in obstetrics, pediatrics, critical care, and mental health nursing. Increasing student admissions to nursing programs require additional clinical learning opportunities to accommodate extra students. Three schools with associate degree nursing programs partnered to identify, implement, and evaluate a creative solution to this dilemma. The resulting quasi-experimental study investigated if substituting half of the conventional clinical experiences with simulations was as effective as traditional clinical activities in obstetrics, pediatrics, mental health, and critical care. One hour of simulation counted for two hours of clinical time. RESULTS Findings indicated combining simulations with conventional clinical experiences resulted in significantly higher scores on the pre-graduation exit exam than traditional clinical experiences alone. Findings have implications for articulation and basic students in associate degree nursing programs.

  13. Wedge Experiment Modeling and Simulation for Reactive Flow Model Calibration

    Science.gov (United States)

    Maestas, Joseph T.; Dorgan, Robert J.; Sutherland, Gerrit T.

    2017-06-01

    Wedge experiments are a typical method for generating pop-plot data (run-to-detonation distance versus input shock pressure), which is used to assess an explosive material's initiation behavior. Such data can be utilized to calibrate reactive flow models by running hydrocode simulations and successively tweaking model parameters until a match between experiment is achieved. Typical simulations are performed in 1D and typically use a flyer impact to achieve the prescribed shock loading pressure. In this effort, a wedge experiment performed at the Army Research Lab (ARL) was modeled using CTH (SNL hydrocode) in 1D, 2D, and 3D space in order to determine if there was any justification in using simplified models. A simulation was also performed using the BCAT code (CTH companion tool) that assumes a plate impact shock loading. Results from the simulations were compared to experimental data and show that the shock imparted into an explosive specimen is accurately captured with 2D and 3D simulations, but changes significantly in 1D space and with the BCAT tool. The difference in shock profile is shown to only affect numerical predictions for large run distances. This is attributed to incorrectly capturing the energy fluence for detonation waves versus flat shock loading. Portions of this work were funded through the Joint Insensitive Munitions Technology Program.

  14. Simulated learning environment experience in nursing students for paediatric practice.

    Science.gov (United States)

    Mendoza-Maldonado, Yessy; Barría-Pailaquilén, René Mauricio

    2018-03-24

    The training of health professionals requires the acquisition of clinical skills in a safe and efficient manner, which is facilitated by a simulated learning environment (SLE). It is also an efficient alternative when there are limitations for clinical practice in certain areas. This paper shows the work undertaken in a Chilean university in implementing paediatric practice using SLE. Over eight days, the care experience of a hospitalized infant was studied applying the nursing process. The participation of a paediatrician, resident physician, nursing technician, and simulated user was included in addition to the use of a simulation mannequin and equipment. Simulation of care was integral and covered interaction with the child and family and was developed in groups of six students by a teacher. The different phases of the simulation methodology were developed from a pedagogical point of view. The possibility of implementing paediatric clinical practice in an efficient and safe way was confirmed. The experience in SLE was highly valued by the students, allowing them to develop different skills and abilities required for paediatric nursing through simulation. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

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

    Science.gov (United States)

    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.

  16. Simulations of the magnetic properties experiment on Mars Exploration Rovers

    International Nuclear Information System (INIS)

    Gunnlaugsson, H. P.; Worm, E. S.; Bertelsen, P.; Goetz, W.; Kinch, K.; Madsen, M. B.; Merrison, J. P.; Nornberg, P.

    2005-01-01

    We present some of the main findings from simulation studies of the Magnetic Properties Experiment on the Mars Exploration Rovers. The results suggest that the dust has formed via mechanical breakdown of surface rocks through the geological history of the planet, and that liquid water need not have played any significant role in the dust formation processes.

  17. Simulation experiments for maximising the availability of a ...

    African Journals Online (AJOL)

    Overall availability of a chemical process is of critical importance in industry. In this paper we evaluate the process design factors that infuence the availability of a new chemical production facility by performing computer experiments on a stochastic simulation model. Experimental designs commonly used in the Design and ...

  18. Simulation with GOTHIC of experiments Oxidation of fuel in Air

    International Nuclear Information System (INIS)

    Martinez-Murillo Mendez, J. C.

    2012-01-01

    In the present work has been addressed for the first time la simulation with the GOTHIC code, experiments oxidation and ignition of SFP in phase 1. This work represents a solid starting point for analysis of specific degradation of fuel in the pools of our facilities.

  19. ANALYSIS OF WELDED POLYPROPYLENE STRUCTURES: COMBINATION OF EXPERIMENTS AND SIMULATIONS

    Directory of Open Access Journals (Sweden)

    Theresa Distlbacher

    2016-02-01

    Full Text Available The effect of joining by extrusion welding on the tensional stiffness and strength of a Polypropylene copolymer was analysed. Short-term and creep tests with laboratory specimens were conducted. Welded joint sub-components were simulated with the finite element method and the results were validated by experiments.

  20. New simulation capability for gamma ray mirror experiments

    Energy Technology Data Exchange (ETDEWEB)

    Descalle, Marie-Anne [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ruz-Armendariz, Jaime [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, Todd [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brejhnolt, Nicolai [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pivovaroff, Michael [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    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.

  1. Optimising electron microscopy experiment through electron optics simulation.

    Science.gov (United States)

    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.

  2. Comparison of GPU-Based Numerous Particles Simulation and Experiment

    International Nuclear Information System (INIS)

    Park, Sang Wook; Jun, Chul Woong; Sohn, Jeong Hyun; Lee, Jae Wook

    2014-01-01

    The dynamic behavior of numerous grains interacting with each other can be easily observed. In this study, this dynamic behavior was analyzed based on the contact between numerous grains. The discrete element method was used for analyzing the dynamic behavior of each particle and the neighboring-cell algorithm was employed for detecting their contact. The Hertzian and tangential sliding friction contact models were used for calculating the contact force acting between the particles. A GPU-based parallel program was developed for conducting the computer simulation and calculating the numerous contacts. The dam break experiment was performed to verify the simulation results. The reliability of the program was verified by comparing the results of the simulation with those of the experiment

  3. Simulation of sodium boiling experiments with THERMIT sodium version. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Huh, K.Y.

    1982-05-01

    Natural and forced convection experiments (SBTF and French) are simulated with the sodium version of the thermal-hydraulic computer code THERMIT. Simulation is done for the test section with the pressure-velocity boundary condition and subsequently extended to the whole loop. For the test section simulation, a steady-state and transient calculations are performed and compared with experimental data. For the loop simulation, two methods are used, a simulated 1-D loop and an actual 1-D loop. In the simulated 1-D loop analysis, the vapor density is increased by one hundred and two hundred times to avoid the code failure and the results still showed some of the important characteristics of the two-phase flow oscillation in a loop. A mathematical model is suggested for the two-phase flow oscillation. In the actual 1-D loop, only the single phase calculation was performed and turned out to be nearly the same as the simulated 1-D loop single phase results.

  4. Simulation of Physical Experiments in Immersive Virtual Environments

    Science.gov (United States)

    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.

  5. Simulation of the BGO-OD experiment at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, Russell [University of Bonn, Physikalisches Institut, Bonn (Germany); Collaboration: BGO-OD-Collaboration

    2011-07-01

    The goal of the BGO Open-Dipole (BGO-OD) project is the systematic investigation of the photoproduction of mesons off the nucleon. These processes are related to the structure of both the mesons and the baryons involved in reactions typical of low-energy hadronic physics. In order to fully understand and accurately interpret the results of the BGO-OD experiment it will be necessary to have a full detector and reaction simulation so that effects from detector resolution and acceptance can be accounted for in the final results. The simulation of the BGO-OD will be be undertaken with the Explora Virtual Monte-Carlo (VMC) software framework. This allows for one common user code to be implemented under Geant4, Geant3 and Fluka. The simulation software is also an analysis tool and such flexibility will be key to an efficient final analysis of the data from the BGO-OD experiment. Presented here are current status of the simulation software for the BGO-OD project and the relevant geometry of the BGO-OD, including the central BGO rugby ball detector with the dual-layer Multiwire Proportional Chambers (MWPCs) and the forward spectrometer, consisting of a large dipole magnet, tracking detectors and the Time-of-Flight walls. Simulation of the magnetic field will also be covered.

  6. Simulations of Validation Platform Experiments by the PSI-Center

    Science.gov (United States)

    Nelson, B. A.; Akcay, C.; Glasser, A. H.; Hansen, C. J.; Jarboe, T. R.; Kim, C. C.; Marklin, G. J.; Milroy, R. D.; Shumlak, U.; Sovinec, C. R.; O'Bryan, J. B.; Held, E.; Ji, J.-Y.; Lukin, V. S.

    2012-10-01

    The Plasma Science and Innovation Center (PSI-Center - http://www.psicenter.org) assists collaborating validation platform experiments with extended MHD simulations. Collaborators include the Bellan Plasma Group (Caltech), CTH (Auburn U), FRX-L (Los Alamos National Laboratory), HIT-SI (U Wash - UW), LDX (M.I.T.), MST & Pegasus (U Wisc-Madison), PHD (UW), PFRC (PPPL), SSX (Swarthmore College), TCS (UW), and ZaP (UW). Modifications have been made to the NIMROD, HiFi, and PSI-Tet codes to specifically model these experiments, including mesh generation/refinement, appropriate boundary conditions (external fields, insulating BCs, etc.), and kinetic and neutral particle interactions. The PSI-Center is planning to add neutrals to NIMROD. When implemented in NIMROD, these results will be compared to the neutral particle physics in the 2D version of HiFi. Coaxial helicity injection BCs will be specified in HiFi to simulate the Caltech co-planar experiment, for verification with previous and ongoing NIMROD simulations. Results from these simulations, as well as an overview of the PSI-Center status will be presented.

  7. Drift Chambers Simulations in BM@N Experiment

    Directory of Open Access Journals (Sweden)

    Fedorišin Ján

    2016-01-01

    Full Text Available Drift chambers constitute an important part of the tracking system of the BM@N experiment designed to study the production of baryonic matter at the Nuclotron energies. GEANT programming package is employed to investigate the drift chamber response to particles produced in relativistic nuclear collisions of C+C nuclei, which are simulated by the UrQMD and LAQGSM Monte Carlo generators. These simulations are combined with the first BM@N experimental data to estimate particle track coordinates and their errors.

  8. Applications of simulation experiments in LMFBR core materials technology

    International Nuclear Information System (INIS)

    Appleby, W.K.

    1976-01-01

    The development of charged particle bombardment experiments to simulate neutron irradiation induced swelling in austenitic alloys is briefly described. The applications of these techniques in LMFBR core materials technology are discussed. It is shown that use of the techniques to study the behavior of cold-worked Type-316 was instrumental in demonstrating at an early date the need for advanced materials. The simulation techniques then were used to identify alloying elements which can markedly decrease swelling and thus a focused reactor irradiation program is now in place to allow the future use of a lower swelling alloy for LMFBR core components

  9. A system for designing and simulating particle physics experiments

    International Nuclear Information System (INIS)

    Zelazny, R.; Strzalkowski, P.

    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 greater, integrated software environment for the design of particle physics experiments, their monitoring and data processing. (orig.)

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

    International Nuclear Information System (INIS)

    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.

    2004-01-01

    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

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

    Science.gov (United States)

    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

  12. Dynamics of cell aggregates fusion: Experiments and simulations

    Science.gov (United States)

    Thomas, Gilberto L.; Mironov, Vladimir; Nagy-Mehez, Agnes; Mombach, José C. M.

    2014-02-01

    Fusion of cell tissues is an ubiquitous phenomenon and has important technological applications including tissue biofabrication. In this work we present experimental results of aggregates fusion using adipose derived stem cells (ADSC) and a three dimensional computer simulation of the process using the cellular Potts model with aggregates reaching 10,000 cells. We consider fusion of round aggregates and monitor the dimensionless neck area of contact between the two aggregates to characterize the process, as done for the coalescence of liquid droplets and polymers. Both experiments and simulations show that the evolution of this quantity obeys a power law in time. We also study quantitatively individual cell motion with the simulation and it corresponds to an anomalous diffusion.

  13. Virtual Reality Simulation of the International Space Welding Experiment

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. Agglomeration processes in carbonaceous dusty plasmas, experiments and numerical simulations

    International Nuclear Information System (INIS)

    Dap, S; Hugon, R; De Poucques, L; Bougdira, J; Lacroix, D; Patisson, F

    2010-01-01

    This paper deals with carbon dust agglomeration in radio frequency acetylene/argon plasma. Two studies, an experimental and a numerical one, were carried out to model dust formation mechanisms. Firstly, in situ transmission spectroscopy of dust clouds in the visible range was performed in order to observe the main features of the agglomeration process of the produced carbonaceous dust. Secondly, numerical simulation tools dedicated to understanding the achieved experiments were developed. A first model was used for the discretization of the continuous population balance equations that characterize the dust agglomeration process. The second model is based on a Monte Carlo ray-tracing code coupled to a Mie theory calculation of dust absorption and scattering parameters. These two simulation tools were used together in order to numerically predict the light transmissivity through a dusty plasma and make comparisons with experiments.

  16. Simulations of ICC Experiments by the PSI-Center

    Science.gov (United States)

    Nelson, Brian; Glasser, A. H.; Jarboe, T. R.; Kim, C. C.; Marklin, G. J.; Lowrie, W.; Meier, E. T.; Milroy, R. D.; Shumlak, U.; Sovinec, C. R.; O'Bryan, J. B.; Held, E.; Ji, J.-Y.; Lukin, V. S.

    2011-10-01

    The Plasma Science and Innovation Center (PSI-Center - http://www.psicenter.org) assists collaborating innovative confinement concept (ICC) experiments with extended MHD simulations. Collaborators include the Bellan Plasma Group (Caltech), CTH (Auburn U), FRX-L (Los Alamos National Laboratory), HIT-SI (U Wash - UW), LDX (M.I.T.), MST & Pegasus (U Wisc-Madison), PHD (UW), PFRC (PPPL), SSX (Swarthmore College), TCS (UW), and ZaP (UW). Modifications have been made to the NIMROD, HiFi, and PSI-Tet codes to specifically model these ICC experiments, including mesh generation/refinement, appropriate boundary conditions (external fields, insulating BCs, etc.), and kinetic and neutral particle interactions. Interfaces of these codes to the powerful 3-D visualization program, VisIt (http://www.llnl.gov/visit) have been developed and implemented. Results from these simulations, as well as an overview of the Interfacing Group status will be presented.

  17. Stream-simulation experiments for waste-repository investigations

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1980-01-01

    The potential for radionuclide migration by groundwater flow from a breached-water repository depends on the leaching process and on chemical changes that might occur as the radionuclide moves away from the repository. Therefore, migration involves the interactions of leached species with (1) the waste and canister, (2) the engineered barrier, and (3) the geologic materials surrounding the repository. Rather than attempt to synthesize each species and study it individually, another approach is to integrate all species and interactions using stream-simulation experiments. Interactions identified in these studies can then be investigated in detail in simpler experiments

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

    Energy Technology Data Exchange (ETDEWEB)

    Odyniec, G.; Cebra, D.; Christie, W.; Naudet, C.; Schroeder, L.; Wilson, W. [Lawrence Berkeley Lab., CA (United States); Liko, D. [Institut fur Hochenenergiephysik, Vienna, (Austria); Cramer, J.; Prindle, D.; Trainor, T. [Univ. of Washington, Seattle (United States); Braithwaite, W. [Univ. of Arkansas, Little Rock (United States)

    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.

  19. Optimising electron microscopy experiment through electron optics simulation

    International Nuclear Information System (INIS)

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

    2017-01-01

    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 300 kV 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. - Highlights: • Using dedicated electron optics software, we calculate full electrons trajectories inside a modern transmission electron microscope. • We have determined how to deal with multi-scale electron optics elements like high voltage cold field emission source. • W • e have succeed to model both weak and strong magnetic lenses whether in saturated or unsaturated conditions as well as electrostatic biprism and magnetic deflectors. • We have applied this model

  20. Simulation of Extreme Arctic Cyclones in IPCC AR5 Experiments

    Science.gov (United States)

    2014-05-15

    Final Technical Report: "Simulation of Extreme Arctic Cyclones in IPCC AR5 Experiments" PI: Stephen Vavrus Nelson Institute Center for Climatic ...cyclones and identify changes in the characteristics of these storms caused by greenhouse-forced climate change to present. OBJECTIVES These goals...emerge in the interior Arctic Ocean, especially over regions where sea ice loss exposes open water. However, this change is not effected by the

  1. Optimising electron microscopy experiment through electron optics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Y. [CEMES-CNRS, 29 Rue Jeanne Marvig, 31055 Toulouse France (France); Hitachi High-Technologies Corporation, 882, Ichige, Hitachinaka, Ibaraki 312-8504 (Japan); Gatel, C.; Snoeck, E. [CEMES-CNRS, 29 Rue Jeanne Marvig, 31055 Toulouse France (France); Houdellier, F., E-mail: florent.houdellier@cemes.fr [CEMES-CNRS, 29 Rue Jeanne Marvig, 31055 Toulouse France (France)

    2017-04-15

    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 300 kV 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. - Highlights: • Using dedicated electron optics software, we calculate full electrons trajectories inside a modern transmission electron microscope. • We have determined how to deal with multi-scale electron optics elements like high voltage cold field emission source. • W • e have succeed to model both weak and strong magnetic lenses whether in saturated or unsaturated conditions as well as electrostatic biprism and magnetic deflectors. • We have applied this model

  2. An Alternative Approach to Simulating an Entire Particle Erosion Experiment

    Directory of Open Access Journals (Sweden)

    Dirk Spaltmann

    2018-03-01

    Full Text Available Solid particle erosion affects many areas, such as dust or volcanic ash in areo-engines. The development of protective materials and surface engineering is costly and time consuming. A lot of effort has been placed into the advancement of models to speed up this process. Finite element or discrete element-based models are quite successful in predicting single or multiple impacts. However, they reach their limit if an entire erosion experiment is to be simulated. Therefore, in the present work, an approach is presented which combines various aspects of the former models with probability considerations. It is used to simulate the impact of more than one billion Alumina particles onto a steel substrate. This approach permits the simulation of an entire erosion experiment on an average PC (i5-2520M CPU@2.5 GHz processor, 4 GB main memory within about six hours. The respective predictions of wear scar and impact-mass/mass-loss curve are compared to the real experiment.

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

    Science.gov (United States)

    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).

  4. Simulating the Long-Distance Propagation of Intense Beams in the Paul Trap Simulator Experiment

    CERN Document Server

    Gilson, Erik P; Davidson, Ronald C; Efthimion, Philip; Majeski, Richard; Startsev, Edward

    2005-01-01

    The Paul Trap Simulator Experiment (PTSX) makes use of a compact Paul trap configuration with quadrupolar oscillating wall voltages to simulate the propagation of intense charged particle beams over distances of many kilometers through magnetic alternating-gradient transport systems. The simulation is possible because of the similarity between the transverse dynamics of particles in the two systems. One-component pure cesium ion plasmas have been trapped that correspond to normalized intensity parameters s < 0.8, where s is the ratio of the square of the plasma frequency to twice the square of the average transverse focusing frequency. The PTSX device confines the plasma for hundreds of milliseconds, which is equivalent to beam propagation over tens of kilometers. Results are presented for experiments in which the amplitude of the oscillating confining voltage waveform has been modified as a function of time. A comparison is made between abrupt changes in amplitude and adiabatic changes in amplitude. T...

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

    Science.gov (United States)

    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

  6. Simulations of Laboratory Astrophysics Experiments using the CRASH code

    Science.gov (United States)

    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.

  7. Burn control simulation experiments in JT-60U

    International Nuclear Information System (INIS)

    Shimomura, K.; Tsutsui, H.; Takenaga, H.

    2006-01-01

    Fusion reactors need to be operated in steady state to be economically competitive. In a burn phase, however, the plasma pressure and heating power are strongly coupled through alpha-particle heating. This strong coupling could easily cause a thermal excursion and finally trigger a disruption without burn control. Hence, burn control simulation experiments were conducted in ELMy H-mode plasmas and reversed shear (RS) plasmas with an internal transport barrier (ITB) in JT-60U. In a subignition simulation scheme, two NB groups were used, where one simulates alpha-particle heating and the other simulates external heating. For the alpha-particle heating simulation, the heating power proportional to the DD neutron yield rate was injected using a real time control system. And the diamagnetically measured stored energy was feedback controlled by external heating to achieve a quasi-steady state. Without burn control both in ELMy H-mode and in RS plasmas, the positive feedback between the neutron yield rate and the heating power was triggered and eventually the plasma disrupted by reaching a beta limit. With burn control in ELMy H-mode or in RS plasmas, where the stored energy was controlled to be constant, the positive feedback was not triggered and the neutron yield rate was kept at a nearly constant value. As another burn control actuator, fueling with a multiple pellet injector will be applied to plasmas with improved confinement. The experimental results are compared with numerical simulation with a 1.5-dimensional time-dependent transport analysis code, TOPICS, and an orbit following Monte-Carlo code, OFMC, to evaluate beam-thermal reaction rates and to estimate optimal burn control gains. (author)

  8. PSI-Center Simulations of Validation Platform Experiments

    Science.gov (United States)

    Nelson, B. A.; Akcay, C.; Glasser, A. H.; Hansen, C. J.; Jarboe, T. R.; Marklin, G. J.; Milroy, R. D.; Morgan, K. D.; Norgaard, P. C.; Shumlak, U.; Victor, B. S.; Sovinec, C. R.; O'Bryan, J. B.; Held, E. D.; Ji, J.-Y.; Lukin, V. S.

    2013-10-01

    The Plasma Science and Innovation Center (PSI-Center - http://www.psicenter.org) supports collaborating validation platform experiments with extended MHD simulations. Collaborators include the Bellan Plasma Group (Caltech), CTH (Auburn U), FRX-L (Los Alamos National Laboratory), HIT-SI (U Wash - UW), LTX (PPPL), MAST (Culham), Pegasus (U Wisc-Madison), PHD/ELF (UW/MSNW), SSX (Swarthmore College), TCSU (UW), and ZaP/ZaP-HD (UW). Modifications have been made to the NIMROD, HiFi, and PSI-Tet codes to specifically model these experiments, including mesh generation/refinement, non-local closures, appropriate boundary conditions (external fields, insulating BCs, etc.), and kinetic and neutral particle interactions. The PSI-Center is exploring application of validation metrics between experimental data and simulations results. Biorthogonal decomposition is proving to be a powerful method to compare global temporal and spatial structures for validation. Results from these simulation and validation studies, as well as an overview of the PSI-Center status will be presented.

  9. IPROP simulations of the GAMBLE II proton transport experiment

    International Nuclear Information System (INIS)

    Welch, D.R.

    1993-01-01

    The author has simulated the proton transport of the 6-kA, 1-MV GAMBLE II experiment using a modified version of the IPROP particle-in-cell code. IPROP now uses a hybrid model in which plasma electrons are divided into high-energy macro particle and thermal-fluid components. This model includes open-quotes knock-onclose quotes bound-electron collision and runaway sources for high-energy electrons. Using IPROP, the authors has calculated net currents in reasonable agreement with the experiment ranging from 5-11% of the total current in pressures from 0.25-4 torr helium. In the simulations, the pinch current sample by the 1.5-cm beam was 2-3 times larger than the net current at 4 cm radius. The attenuation of net current at larger radii was the result of a highly-conductive energetic component of plasma electrons surrounding the beam. Having benchmarked IPROP against experiment, the author has examined higher-current ion beams with respect to possible transport for inertial confinement fusion

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Combining Experiments and Simulations Using the Maximum Entropy Principle

    DEFF Research Database (Denmark)

    Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten

    2014-01-01

    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...... 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....... 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....

  12. Satellite hole formation during dewetting: experiment and simulation

    CERN Document Server

    Neto, C; Seemann, R; Blossey, R; Becker, J; Grün, G

    2003-01-01

    The dewetting of thin polymer films on solid substrates has been studied extensively in recent years. These films can decay either by nucleation events or by spinodal dewetting, essentially only depending on the interface potential describing the short- and long-range intermolecular interactions between the interfaces and the initial film thickness. Here, we describe experiments and simulations concerned with the decay of polystyrene thin films. The rupture of the film occurs by the formation of a correlated pattern of holes ('satellite holes') along the liquid rims accumulating at the channel borders. The development of this complex film rupture process, which is neither simply spinodal nor nucleation dewetting, can be mimicked precisely by making use of a novel simulation code based on a rigorous mathematical treatment of the thin film equation and on the knowledge of the effective interface potential of the system. The conditions that determine the appearance and the position of the satellite holes around ...

  13. Experiments and Simulations of a Spinner-Flask Bioreactor

    Science.gov (United States)

    Sucosky, Philippe; Osorio, Diego; Neitzel, G. Paul

    2001-11-01

    Spinner-flask bioreactors are used for the culture of living tissues; specifically, we investigate a configuration used for producing articular cartilage. Laboratory measurements are made in a model spinner flask employing index-of-refraction matching and particle-image velocimetry to determine mean-flow and turbulence quantities for a time-periodic turbulent flow; the periodicity of the flow requires the use of phase-locked ensemble averaging. Companion numerical simulations have been performed using the commercial package Fluent. The stir-bar region is handled with a separate, moving grid. Results to be presented from both experiment and simulation are in reasonably good agreement with one another. Suggestions for the improvement of both approaches will be discussed, along with the implications of the results for cartilage growth in spinner flasks.

  14. Simulations of MATROSHKA experiments at ISS using PHITS

    CERN Document Server

    Sihver, L; Puchalska, M; Reitz, G

    2010-01-01

    Concerns about the biological effects of space radiation are increasing rapidly due to the perspective 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 preparation 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 radiation 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 experiment MATROSHKA (MTR), which is an anthropomorphic phantom containing over 6000 radiation detecto...

  15. Comparison of simulation with experiment in an RFQ

    International Nuclear Information System (INIS)

    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

  16. The TESS [Tandem Experiment Simulation Studies] computer code user's manual

    International Nuclear Information System (INIS)

    Procassini, R.J.

    1990-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Williams B

    2016-03-01

    Full Text Available Brett Williams,1 Chloe Abel,1 Eihab Khasawneh,2 Linda Ross,1 Tracy Levett-Jones31Department of Community Emergency Health & Paramedic Practice, Monash University, Frankston, Victoria, Australia; 2Faculty of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, Jordan; 3School of Nursing and Midwifery, The University of Newcastle, Callaghan, New South Wales, AustraliaBackground: 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.Objective: This study aimed to compare simulation satisfaction among paramedic students from universities in Australia and Jordan.Methods: 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.Results: 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.Conclusion: 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

  18. Simulations, Diagnostics and Recent Results of the VISA II Experiment

    CERN Document Server

    Andonian, G; Pellegrini, C; Reiche, S; Rosenzweig, J B; Travish, G

    2005-01-01

    The VISA II experiment entails use of a chirped beam to drive a high gain SASE FEL. The output radiation is diagnosed with a modified frequency resolved optical gating (FROG) technique. Sextupoles are implemented to correct the lonigtudinal aberrations affecting the high energy spread chirped beam during transport to the undulator. The double differential energy spectrum is measured with a pair of slits and a set of gratings. In this paper, we report on start-to-end simulations, radiation diagnostics, as well as intial experimental results; experimental methods are described.

  19. Colloids dragged through a polymer solution: Experiment, theory, and simulation.

    Science.gov (United States)

    Gutsche, Christof; Kremer, Friedrich; Krüger, Matthias; Rauscher, Markus; Weeber, Rudolf; Harting, Jens

    2008-08-28

    We present microrheological measurements of the drag force on colloids pulled through a solution of lambda-DNA (used here as a monodisperse model polymer) with an optical tweezer. The experiments show a drag force that is larger than expected from the Stokes formula and the independently measured viscosity of the DNA solution. We attribute this to the accumulation of DNA in front of the colloid and the reduced DNA density behind the colloid. This hypothesis is corroborated by a simple drift-diffusion model for the DNA molecules, which reproduces the experimental data surprisingly well, as well as by corresponding Brownian dynamics simulations.

  20. The single-beam funnel demonstration: Experiment and simulation

    International Nuclear Information System (INIS)

    Johnson, K.F.; Sander, O.R.; Bolme, G.O.; Gilpatrick, J.D.; Guy, F.W.; Marquardt, J.H.; Sandoval, D.; Yuan, V.; Saadatmand, K.

    1991-01-01

    Accelerator concepts for heavy-ion fusion and for the transmutation of nuclear waste require small-emittance, high-current beams. Such applications include funnels in which high-current, like-charged particle beams are interlaced to double the beam current. The first experimental demonstration confirming the beam dynamics of the funnel principle (with contained emittance growth) was recently completed at Los Alamos National Laboratory. A single leg of a prototype 5-MeV, H - funnel was successfully tested. This single-beam demonstration explored physics issues of a two-beam funnel. The experiment contained elements for emittance control, position control, and rf-deflection. Diagnostics allowed measurement of beam intensity, position and angle centroids, energy and phase centroids, transverse and longitudinal phase-space distributions. Results of the experiment will be presented along with comparisons to simulations

  1. An experiment teaching method based on the Optisystem simulation platform

    Science.gov (United States)

    Zhu, Jihua; Xiao, Xuanlu; Luo, Yuan

    2017-08-01

    The experiment teaching of optical communication system is difficult to achieve because of expensive equipment. The Optisystem is optical communication system design software, being able to provide such a simulation platform. According to the characteristic of the OptiSystem, an approach of experiment teaching is put forward in this paper. It includes three gradual levels, the basics, the deeper looks and the practices. Firstly, the basics introduce a brief overview of the technology, then the deeper looks include demoes and example analyses, lastly the practices are going on through the team seminars and comments. A variety of teaching forms are implemented in class. The fact proves that this method can not only make up the laboratory but also motivate the students' learning interest and improve their practical abilities, cooperation abilities and creative spirits. On the whole, it greatly raises the teaching effect.

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

    Science.gov (United States)

    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

  3. Chaos in reversed-field-pinch plasma simulation and experiment

    International Nuclear Information System (INIS)

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

    1994-01-01

    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 Poincare 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 computer code, which models global RFP dynamics, and the dissipative trapped-electron-mode 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 that the experimental system is very high dimensional with properties similar to noise. Nonlinear noise reduction is unsuccessful at extracting an underlying deterministic system

  4. Shocked materials at the intersection of experiment and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kadau, Kai [Los Alamos National Laboratory

    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.

  5. A simulation of the San Andreas fault experiment

    Science.gov (United States)

    Agreen, R. W.; Smith, D. E.

    1974-01-01

    The San Andreas fault experiment (Safe), which employs two laser tracking systems for measuring the relative motion of two points on opposite sides of the fault, has been simulated for an 8-yr observation period. The two tracking stations are located near San Diego on the western side of the fault and near Quincy on the eastern side; they are roughly 900 km apart. Both will simultaneously track laser reflector equipped satellites as they pass near the stations. Tracking of the Beacon Explorer C spacecraft has been simulated for these two stations during August and September for 8 consecutive years. An error analysis of the recovery of the relative location of Quincy from the data has been made, allowing for model errors in the mass of the earth, the gravity field, solar radiation pressure, atmospheric drag, errors in the position of the San Diego site, and biases and noise in the laser systems. The results of this simulation indicate that the distance of Quincy from San Diego will be determined each year with a precision of about 10 cm. Projected improvements in these model parameters and in the laser systems over the next few years will bring the precision to about 1-2 cm by 1980.

  6. Shocked materials at the intersection of experiment and simulation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Wireless Power Transfer Protocols in Sensor Networks: Experiments and Simulations

    Directory of Open Access Journals (Sweden)

    Sotiris Nikoletseas

    2017-04-01

    Full Text Available Rapid technological advances in the domain of Wireless Power Transfer pave the way for novel methods for power management in systems of wireless devices, and recent research works have already started considering algorithmic solutions for tackling emerging problems. In this paper, we investigate the problem of efficient and balanced Wireless Power Transfer in Wireless Sensor Networks. We employ wireless chargers that replenish the energy of network nodes. We propose two protocols that configure the activity of the chargers. One protocol performs wireless charging focused on the charging efficiency, while the other aims at proper balance of the chargers’ residual energy. We conduct detailed experiments using real devices and we validate the experimental results via larger scale simulations. We observe that, in both the experimental evaluation and the evaluation through detailed simulations, both protocols achieve their main goals. The Charging Oriented protocol achieves good charging efficiency throughout the experiment, while the Energy Balancing protocol achieves a uniform distribution of energy within the chargers.

  8. The World Climate Exercise: Is (Simulated) Experience Our Best Teacher?

    Science.gov (United States)

    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

  9. Two-phase simulation of a variable rate infiltration experiment

    Science.gov (United States)

    Luvisotto, V.; Manoli, G.; Cainelli, O.; Bellin, A.; Marani, M.; Putti, M.

    2012-04-01

    Flow and transport processes in unsaturated soils are typically modeled through Richards' equation with retention and hydraulic conductivity curves obtained under static and stationary conditions, respectively. This model is commonly applied to quantify infiltration at the hillslope scale under strongly varying rainfall intensity, which leads to varying infiltration rates. To our knowledge detailed laboratory experiments reproducing this situation in large columns of length comparable with the soil thickness in Alpine hillslopes are lacking. In the present work we analyze and model variable rate infiltration experiments performed in a sand column accurately instrumented with tensiometers and TDR probes. Previous analyses revealed that data collected during transient experiments are not falling within the main wetting and drying curves obtained with careful analysis under static conditions. On the other hand, as expected, the same retention curves were able to reproduce with high accuracy experiments conducted under quasi-static conditions. As a consequence, the Richards' model was unable to reproduce the pressure distribution along the column during transient experiments conducted with variable rainfall rates. These findings have important consequences, e.g. for the prediction of runoff production and hill-slope stability. We propose that this discrepancy may be due to the influence of air flow on water pressure which is expected to be much higher under variable rainfall conditions when rapid saturation of the top soil may limit air to escape from above. In the present work, we numerically investigated this hypothesis using a two-phase air-water flow model. The numerical solver is based on a linear FEM-based pressure-pressure formulation where accurate mass balance is preserved by careful choice of spatial and temporal discretization of the nonlinear terms. The pressure-pressure formulation is chosen to ensure proper implementation of the pressure-based boundary

  10. Simulation experiments for radiologic inspection inside a nuclear reactor

    Science.gov (United States)

    Wei, W.; Murphy, R. V.; Sonnenburg, D. K.

    1996-02-01

    Experiments were performed in a gamma cell to simulate radiologic inspection inside a CANDU nuclear power reactor. Radiation in the gamma cell is similar, both in magnitude and directions, to that in a shut down CANDU reactor. The inspection consists of detecting garter spring spacers used to maintain the gap between pressure tubes and calandria tubes in CANDU reactors. A shielding head made of tungsten alloy was placed inside a pressure tube. A glass scintillator was used as the gamma radiation detector. The scintillation light travelled through a fiber-optic light guide to the radiation-free environment outside the gamma cell, where the light was detected by a light sensor. Earlier experiments used a high-resolution CCD (charge coupled device) camera to capture images transferred through a high-resolution fiberscope. Later experiments used silicon photodiodes to measure the intensity of the light transferred through a fiber bundle that was made in-house. The light intensity approach was found to be more suitable for the detection of garter springs. The removal of the garter spring resulted in an immediate increase in the intensity of the scintillation light. Experimental results in the gamma cell show great promise for constructing a real-time garter spring detection tool for use in CANDU reactors.

  11. A teaching experience using a flight simulator: Educational Simulation in practice

    Directory of Open Access Journals (Sweden)

    Sergio Ruiz

    2014-09-01

    Full Text Available The use of appropriate Educational Simulation systems (software and hardware for learning purposes may contribute to the application of the “Learning by Doing” (LbD paradigm in classroom, thus helping the students to assimilate the theoretical concepts of a subject and acquire certain pre-defined competencies in a more didactical way. The main objective of this work is to conduct a teaching experience using a flight simulation environment so that the students of Aeronautical Management degree can assume the role of an aircraft pilot, in order to allow the students understanding the basic processes of the air navigation and observe how the new technologies can transform and improve these processes. This is especially helpful in classroom to teach the contents of the Single European Sky ATM Research (SESAR programme, an European project that introduces a new Air Traffic Management (ATM paradigm based on several relevant technological and procedural changes that will affect the entire air transportation system in the short and medium term. After the execution of several activities with a flight simulator in the classroom a short test and a satisfaction survey have been requested to the students in order to assess the teaching experience.

  12. A Facility for Long-Term Mars Simulation Experiments: The Mars Environmental Simulation Chamber (MESCH)

    Science.gov (United States)

    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 N2 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°C), low atmospheric pressure (5 10 mbar), and a gas composition like that of Mars during long-term experiments.

  13. External individual monitoring: experiments and simulations using Monte Carlo Method

    International Nuclear Information System (INIS)

    Guimaraes, Carla da Costa

    2005-01-01

    In this work, we have evaluated the possibility of applying the Monte Carlo simulation technique in photon dosimetry of external individual monitoring. The GEANT4 toolkit was employed to simulate experiments with radiation monitors containing TLD-100 and CaF 2 :NaCl thermoluminescent detectors. As a first step, X ray spectra were generated impinging electrons on a tungsten target. Then, the produced photon beam was filtered in a beryllium window and additional filters to obtain the radiation with desired qualities. This procedure, used to simulate radiation fields produced by a X ray tube, was validated by comparing characteristics such as half value layer, which was also experimentally measured, mean photon energy and the spectral resolution of simulated spectra with that of reference spectra established by international standards. In the construction of thermoluminescent dosimeter, two approaches for improvements have. been introduced. The first one was the inclusion of 6% of air in the composition of the CaF 2 :NaCl detector due to the difference between measured and calculated values of its density. Also, comparison between simulated and experimental results showed that the self-attenuation of emitted light in the readout process of the fluorite dosimeter must be taken into account. Then, in the second approach, the light attenuation coefficient of CaF 2 :NaCl compound estimated by simulation to be 2,20(25) mm -1 was introduced. Conversion coefficients C p from air kerma to personal dose equivalent were calculated using a slab water phantom with polymethyl-metacrilate (PMMA) walls, for reference narrow and wide X ray spectrum series [ISO 4037-1], and also for the wide spectra implanted and used in routine at Laboratorio de Dosimetria. Simulations of backscattered radiations by PMMA slab water phantom and slab phantom of ICRU tissue-equivalent material produced very similar results. Therefore, the PMMA slab water phantom that can be easily constructed with low

  14. Rainfall simulation experiments in the southwestern USA using the Walnut Gulch Rainfall Simulator

    Science.gov (United States)

    Polyakov, Viktor; Stone, Jeffry; Holifield Collins, Chandra; Nearing, Mark A.; Paige, Ginger; Buono, Jared; Gomez-Pond, Rae-Landa

    2018-01-01

    This dataset contains hydrological, erosion, vegetation, ground cover, and other supplementary information from 272 rainfall simulation experiments conducted on 23 semiarid rangeland locations in Arizona and Nevada between 2002 and 2013. On 30 % of the plots, simulations were conducted up to five times during the decade of study. The rainfall was generated using the Walnut Gulch Rainfall Simulator on 2 m by 6 m plots. Simulation sites included brush and grassland areas with various degrees of disturbance by grazing, wildfire, or brush removal. This dataset advances our understanding of basic hydrological and biological processes that drive soil erosion on arid rangelands. It can be used to estimate runoff, infiltration, and erosion rates at a variety of ecological sites in the Southwestern USA. The inclusion of wildfire and brush treatment locations combined with long-term observations makes it important for studying vegetation recovery, ecological transitions, and the effect of management. It is also a valuable resource for erosion model parameterization and validation. The dataset is available from the National Agricultural Library at search/type/dataset" target="_blank">https://data.nal.usda.gov/search/type/dataset (DOI: https://doi.org/10.15482/USDA.ADC/1358583).

  15. Aerodynamics of ski jumping: experiments and CFD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Meile, W.; Reisenberger, E.; Brenn, G. [Graz University of Technology, Institute of Fluid Mechanics and Heat Transfer, Graz (Austria); Mayer, M. [VRVis GmbH, Vienna (Austria); Schmoelzer, B.; Mueller, W. [Medical University of Graz, Department for Biophysics, Graz (Austria)

    2006-12-15

    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. (orig.)

  16. Aerodynamics of ski jumping: experiments and CFD simulations

    Science.gov (United States)

    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.

  17. Linking Well-Tempered Metadynamics Simulations with Experiments

    Science.gov (United States)

    Barducci, Alessandro; Bonomi, Massimiliano; Parrinello, Michele

    2010-01-01

    Abstract Linking experiments with the atomistic resolution provided by molecular dynamics simulations can shed light on the structure and dynamics of protein-disordered states. The sampling limitations of classical molecular dynamics can be overcome using metadynamics, which is based on the introduction of a history-dependent bias on a small number of suitably chosen collective variables. Even if such bias distorts the probability distribution of the other degrees of freedom, the equilibrium Boltzmann distribution can be reconstructed using a recently developed reweighting algorithm. Quantitative comparison with experimental data is thus possible. Here we show the potential of this combined approach by characterizing the conformational ensemble explored by a 13-residue helix-forming peptide by means of a well-tempered metadynamics/parallel tempering approach and comparing the reconstructed nuclear magnetic resonance scalar couplings with experimental data. PMID:20441734

  18. Experiences using DAKOTA stochastic expansion methods in computational simulations.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Color film spectral properties test experiment for target simulation

    Science.gov (United States)

    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.

  20. Social Network Mixing Patterns In Mergers & Acquisitions - A Simulation Experiment

    Directory of Open Access Journals (Sweden)

    Robert Fabac

    2011-01-01

    Full Text Available In the contemporary world of global business and continuously growing competition, organizations tend to use mergers and acquisitions to enforce their position on the market. The future organization’s design is a critical success factor in such undertakings. The field of social network analysis can enhance our uderstanding of these processes as it lets us reason about the development of networks, regardless of their origin. The analysis of mixing patterns is particularly useful as it provides an insight into how nodes in a network connect with each other. We hypothesize that organizational networks with compatible mixing patterns will be integrated more successfully. After conducting a simulation experiment, we suggest an integration model based on the analysis of network assortativity. The model can be a guideline for organizational integration, such as occurs in mergers and acquisitions.

  1. First experience of vectorizing electromagnetic physics models for detector simulation

    Energy Technology Data Exchange (ETDEWEB)

    Amadio, G. [Sao Paulo State U.; Apostolakis, J. [CERN; Bandieramonte, M. [Catania Astrophys. Observ.; Bianchini, C. [Mackenzie Presbiteriana U.; Bitzes, G. [CERN; Brun, R. [CERN; Canal, P. [Fermilab; Carminati, F. [CERN; Licht, J.de Fine [U. Copenhagen (main); Duhem, L. [Intel, Santa Clara; Elvira, D. [Fermilab; Gheata, A. [CERN; Jun, S. Y. [Fermilab; Lima, G. [Fermilab; Novak, M. [CERN; Presbyterian, M. [Bhabha Atomic Res. Ctr.; Shadura, O. [CERN; Seghal, R. [Bhabha Atomic Res. Ctr.; Wenzel, S. [CERN

    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. Simulations and experiments of self-associating telechelic polymer solutions

    Energy Technology Data Exchange (ETDEWEB)

    Cass, M J; Heyes, D M [Division of Chemical Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom); Blanchard, R-L; English, R J [Centre for Water Soluble Polymers, North East Wales Institute of Higher Education, Plas Coch Campus, Mold Road, Wrexham LL11 2AW (United Kingdom)], E-mail: d.heyes@surrey.ac.uk, E-mail: englishr@newi.ac.uk

    2008-08-20

    A Brownian dynamics computer simulation study of a highly coarse-grained model of telechelic associating polymers has been carried out. In a critical concentration range the model produces the so-called 'loops-to-bridges' transition, thought to exist in the experimental systems, in which the two hydrophobic groups are in different micelles, thereby forming a highly interconnected, ultimately percolating, network. The fraction of bridged polymers produced by the model correlates well with the experimental viscosity at corresponding concentrations. The distribution of micelle sizes compares favorably with the predictions of the Meng-Russell free energy theory. The mean cluster size scales well with volume occupancy according to a simple mean-field theory. The stress relaxation function is a stretched exponential at short times and not too high concentrations but develops a longer time plateau in the percolation region, both in agreement with experiment. New experimental data for the concentration dependence of the self-diffusion coefficient, viscosity, elastic modulus and relaxation time of telechelic associative polymers are presented, which show broad qualitative agreement with the simulation data.

  3. Numerical simulation of the Perrin-like experiments

    Science.gov (United States)

    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 langr2rang = 2Dt, where the diffusion constant D is expressed by the mass and geometry of a particle, the viscosity of a liquid and the average effective time between consecutive collisions of the tracked particle with liquid molecules. The latter allows us to make a simulation of the Perrin experiment and to verify in the detailed study the influence of the statistics on the expected theoretical results. To avoid the problem of small statistics causing departures from the diffusion law we introduce in the second part of the paper the idea of the so-called artificially increased statistics (AIS), and we prove that, within this method of experimental data analysis, one can confirm the diffusion law and get a good prediction for the diffusion constant even if trajectories of just a few particles immersed in a liquid are considered.

  4. Theory and Simulation of an Inverse Free Electron Laser Experiment

    Science.gov (United States)

    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.

  5. Simulation in computer forensics teaching: the student experience

    OpenAIRE

    Crellin, Jonathan; Adda, Mo; Duke-Williams, Emma; Chandler, Jane

    2011-01-01

    The use of simulation in teaching computing is well established, with digital forensic investigation being a subject area where the range of simulation required is both wide and varied demanding a corresponding breadth of fidelity. Each type of simulation can be complex and expensive to set up resulting in students having only limited opportunities to participate and learn from the simulation. For example students' participation in mock trials in the University mock courtroom or in simulation...

  6. Experience producing simulated events for the DZero experiment on the SAM-Grid

    Energy Technology Data Exchange (ETDEWEB)

    Garzoglio, G.; Terekhov, I.; /Fermilab; Snow, J.; /Langston U.; 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.

  7. CLARREO shortwave observing system simulation experiments of the twenty-first century: Simulator design and implementation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Transient Simulation of the Multi-SERTTA Experiment with MAMMOTH

    Energy Technology Data Exchange (ETDEWEB)

    Ortensi, Javier [Idaho National Lab. (INL), Idaho Falls, ID (United States); Baker, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Yaqi [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schunert, Sebastian [Idaho National Lab. (INL), Idaho Falls, ID (United States); deHart, Mark [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-07-11

    This work details the MAMMOTH reactor physics simulations of the Static Environment Rodlet Transient Test Apparatus (SERTTA) conducted at Idaho National Laboratory in FY-2017. TREAT static-environment experiment vehicles are being developed to enable transient testing of Pressurized Water Reactor (PWR) type fuel specimens, including fuel concepts with enhanced accident tolerance (Accident Tolerant Fuels, ATF). The MAMMOTH simulations include point reactor kinetics as well as spatial dynamics for a temperature-limited transient. The strongly coupled multi-physics solutions of the neutron flux and temperature fields are second order accurate both in the spatial and temporal domains. MAMMOTH produces pellet stack powers that are within 1.5% of the Monte Carlo reference solutions. Some discrepancies between the MCNP model used in the design of the flux collars and the Serpent/MAMMOTH models lead to higher power and energy deposition values in Multi-SERTTA unit 1. The TREAT core results compare well with the safety case computed with point reactor kinetics in RELAP5-3D. The reactor period is 44 msec, which corresponds to a reactivity insertion of 2.685% delta k/k$. The peak core power in the spatial dynamics simulation is 431 MW, which the point kinetics model over-predicts by 12%. The pulse width at half the maximum power is 0.177 sec. Subtle transient effects are apparent at the beginning insertion in the experimental samples due to the control rod removal. Additional difference due to transient effects are observed in the sample powers and enthalpy. The time dependence of the power coupling factor (PCF) is calculated for the various fuel stacks of the Multi-SERTTA vehicle. Sample temperatures in excess of 3100 K, the melting point UO$_2$, are computed with the adiabatic heat transfer model. The planned shaped-transient might introduce additional effects that cannot be predicted with PRK models. Future modeling will be focused on the shaped-transient by improving the

  9. Simulation of signal and background processes for collider experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, S.

    2008-10-08

    In this thesis new theoretical tools for the accurate simulation of scattering processes at present and future collider experiments have been developed. Special emphasis has thereby to be given to multi-particle/multi-jet final states that often constitute signals for interesting (new) physics. Considering final states with a number of hard jets, there seems to be enough evidence that the traditional simulation tools HERWIG and PYTHIA cannot fully accomplish their description. Starting from a 2{yields}2 core process, they account only for soft and collinear QCD emissions through parton-shower models. Only recently, theoretical prescriptions have been found to consistently combine tree-level matrix-element calculations with the existing parton-shower algorithms. The gain of such methods is that phase-space regions covered by hard and by soft parton kinematics are simultaneously well described. In Chapter 2 of this thesis the working principles of such prescriptions have been discussed with special attention being paid to the merging scheme implemented in the SHERPA Monte Carlo. To consistently match QCD higher-order calculations (at one-loop or tree-level) with parton showers, a good analytical control over the perturbative terms present in the latter is required. This has triggered the demand for improved parton-shower models that facilitate the inclusion of exact matrix elements. In this line a completely new shower algorithm has been presented in Chapter 3. It is based on the Catani-Seymour dipole subtraction formalism, a universal method for calculating arbitrary processes at next-to-leading order in QCD. The splitting kernels used in the shower are justified approximations of the Catani-Seymour dipole functions. The kinematics of the individual splittings is accomplished such that exact four-momentum conservation can be ensured for each single branching. Accordingly, the shower can be stopped and started again at each intermediate stage of the evolution. The

  10. The INAF/IAPS Plasma Chamber for ionospheric simulation experiment

    Science.gov (United States)

    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

  11. LABORATORY EXPERIMENTS TO SIMULATE CO2 OCEAN DISPOSAL

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Modelling, simulation and experiment of the spherical flexible joint stiffness

    Directory of Open Access Journals (Sweden)

    S. Li

    2018-02-01

    Full Text Available The spherical flexible joint is extensively used in engineering. It is designed to provide flexibility in rotation while bearing vertical compression load. The linear rotational stiffness of the flexible joint is formulated. The rotational stiffness of the bonded rubber layer is related to inner radius, thickness and two edge angles. FEM is used to verify the analytical solution and analyze the stiffness. The Mooney–Rivlin, Neo Hooke and Yeoh constitutive models are used in the simulation. The experiment is taken to obtain the material coefficient and validate the analytical and FEM results. The Yeoh model can reflect the deformation trend more accurately, but the error in the nearly linear district is bigger than the Mooney–Rivlin model. The Mooney–Rivlin model can fit the test result very well and the analytical solution can also be used when the rubber deformation in the flexible joint is small. The increase of Poisson's ratio of the rubber layers will enhance the vertical compression stiffness but barely have effect on the rotational stiffness.

  13. A simulation experiment of photochemical reactions in the mesosphere

    Science.gov (United States)

    Fugono, N.

    1975-01-01

    An ionospheric simulation experiment has been performed in a large vacuum chamber. The chamber is filled with NO and other gases including N2, O2, CO2, NH3 and H2O in the pressure range of 0.01 torr. A lamp which produces photons at 1236- and 1165-A by means of microwave discharge in krypton is utilized as an ionization source. In addition to 30+ large quantities of the water cluster ions 55+, H3O(+).(H2O)2, 73+, H3O(+).(H2O)3 and 91+, H3O(+).(H2O)4 were observed when nitric oxide and water were present. This closely approximates the condition of the terrestrial D region. After long periods of UV irradiation 74+ and 104+ ions grow in intensity. These ions are tentatively identified as NO(+).N2O and NO(+).NO.N2O. In addition the series 18+, 36+, 54+, and 72+ is detected which can be labeled NH4(+), NH4(+).(H2O), NH4(+).(H2O)2 and NH4(+).(H2O)3. These same species of ions are observed with the introduction of ammonia into the chamber. Presumably both N2O and NH3 are products of the photolysis.

  14. Simulations: Capturing the Experience of the Real Thing.

    Science.gov (United States)

    Wehrenberg, Stephen B.

    1986-01-01

    Explains why simulation is a particularly useful teaching device in areas in which it is important to tie together cognitive skills and motor skills into total performance. Discusses the many forms simulation can take in soft skills training and how simulations can shape perspectives. (CT)

  15. Current experience with nuclear power plant simulators and analysers

    International Nuclear Information System (INIS)

    Drozd, A.

    1998-01-01

    Topics of a Specialist Meeting are presented on Simulators and Plant Analyzers: Current Issues in Nuclear Power Plant Simulation (Espoo, Finland). They dealt with the need for maintaining expertise, training and education, control rooms and operator support tools, simulators as tools for plant safety analysis. The major conclusions of the payers and the meeting are discussed. (R.P.)

  16. Magnetic separation in microfluidic systems using microfabricated electromagnets - Experiments and simulations

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Hansen, Ole; Bruus, Henrik

    2005-01-01

    We present experiments and simulations of magnetic separation of magnetic beads in a microfluidic channel. The separation is obtained by microfabricated electromagnets. The results of our simulations using FEMLAB and Mathematica are compared with experimental results obtained using our own...

  17. Simulation of water hammer experiments using RELAP5 code

    International Nuclear Information System (INIS)

    Kaliatka, A.; Vaisnoras, M.

    2005-01-01

    The rapid closing or opening of a valve causes pressure transients in pipelines. The fast deceleration of the liquid results in high pressure surges upstream the valve, thus the kinetic energy is transformed into the potential energy, which leads to the temporary pressure increases. This phenomenon is called water hammer. The intensity of water hammer effects will depend upon the rate of change in the velocity or momentum. Generally water hammer can occur in any thermal-hydraulic systems and it is extremely dangerous for the thermal-hydraulic system since, if the pressure induced exceeds the pressure range of a pipe given by the manufacturer, it can lead to the failure of the pipeline integrity. Due to its potential for damage of pipes, water hammer has been a subject of study since the middle of the nineteenth century. Many theoretical and experimental investigations were performed. The experimental investigation of the water hammer tests performed at Fraunhofer Institute for Environmental, Safety and Energy Technology (UMSICHT) [1] and Cold Water Hammer experiment performed by Forschungszentrum Rossendorf (CWHTF) [2] should be mentioned. The UMSICHT facility in Oberhausen was modified in order to simulate a piping system and associated supports that are typical for a nuclear power plant [3]. The Cold water hammer experiment is interesting and instructive because it covers a wide spectrum of particularities. One of them is sub-cooled water interaction with condensing steam at the closed end of the vertical pipe at room temperature and corresponding saturation pressure [4]. In the paper, the capabilities of RELAP5 code to correctly represent the water hammer phenomenon are presented. Paper presents the comparison of RELAP5 calculated and measured at UMSICHT and CWHTF test facilities pressure transient values after the fast closure (opening) of valves. The analyses of rarefaction wave travels inside the pipe and condensation of vapour bubbles in the liquid column

  18. Rheology of dense granular chute flow: simulations to experiments

    Directory of Open Access Journals (Sweden)

    Bharathraj S

    2017-01-01

    Full Text Available Granular chute flow simulations reveal an interesting transition from a random disordered structure to an ordered one with hexagonally ordered sheets of spherical particles, when the base roughness is modulated. Two types of base roughness are considered. The first is a fixed base, where glued spherical particles form the base, and the base roughness is varied by changing the ratio of diameters of the base and flowing particles. In the second sinusoidal base, a smooth wall with sinusoidal height variation is used; the amplitude and wavelength of the base modulation determine the base roughness. The transition is studied as a function of these roughness parameters. For the fixed base, there is a critical base particle diameter below which ordered states are observed. For the sinusoidal base, the critical amplitude increases linearly with the wavelength at lower wavelengths, reaches a maximum depending on the height of the flowing layer, and then decreases as the wavelength is further increased. There is flow for angles of inclination from 15 ° ≤ θ ≤ 25 ° for the ordered state and 20 ° ≤ θ ≤ 25 ° for the disordered state. Flow confinement by sidewalls also influences the rheology of the system and we see that the ordering is induced by the sidewalls as well. Experiments on chute flow at low angles indicate the presence of two types of rheology depending on the system height. A transition is observed from an erodible base configuration, where a dead zone at the bottom supports a free surface reposing at the top, to a Bagnold rheology with considerable slip at the bottom.

  19. A benchmark on computational simulation of a CT fracture experiment

    International Nuclear Information System (INIS)

    Franco, C.; Brochard, J.; Ignaccolo, S.; Eripret, C.

    1992-01-01

    For a better understanding of the fracture behavior of cracked welds in piping, FRAMATOME, EDF and CEA have launched an important analytical research program. This program is mainly based on the analysis of the effects of the geometrical parameters (the crack size and the welded joint dimensions) and the yield strength ratio on the fracture behavior of several cracked configurations. Two approaches have been selected for the fracture analyses: on one hand, the global approach based on the concept of crack driving force J and on the other hand, a local approach of ductile fracture. In this approach the crack initiation and growth are modelized by the nucleation, growth and coalescence of cavities in front of the crack tip. The model selected in this study estimates only the growth of the cavities using the RICE and TRACEY relationship. The present study deals with a benchmark on computational simulation of CT fracture experiments using three computer codes : ALIBABA developed by EDF the CEA's code CASTEM 2000 and the FRAMATOME's code SYSTUS. The paper is split into three parts. At first, the authors present the experimental procedure for high temperature toughness testing of two CT specimens taken from a welded pipe, characteristic of pressurized water reactor primary piping. Secondly, considerations are outlined about the Finite Element analysis and the application procedure. A detailed description is given on boundary and loading conditions, on the mesh characteristics, on the numerical scheme involved and on the void growth computation. Finally, the comparisons between numerical and experimental results are presented up to the crack initiation, the tearing process being not taken into account in the present study. The variations of J and of the local variables used to estimate the damage around the crack tip (triaxiality and hydrostatic stresses, plastic deformations, void growth ...) are computed as a function of the increasing load

  20. Simulation Experiment Description Markup Language (SED-ML) Level 1 Version 3 (L1V3).

    Science.gov (United States)

    Bergmann, Frank T; Cooper, Jonathan; König, Matthias; Moraru, Ion; Nickerson, David; Le Novère, Nicolas; Olivier, Brett G; Sahle, Sven; Smith, Lucian; Waltemath, Dagmar

    2018-03-19

    The creation of computational simulation experiments to inform modern biological research poses challenges to reproduce, annotate, archive, and share such experiments. Efforts such as SBML or CellML standardize the formal representation of computational models in various areas of biology. The Simulation Experiment Description Markup Language (SED-ML) describes what procedures the models are subjected to, and the details of those procedures. These standards, together with further COMBINE standards, describe models sufficiently well for the reproduction of simulation studies among users and software tools. The Simulation Experiment Description Markup Language (SED-ML) is an XML-based format that encodes, for a given simulation experiment, (i) which models to use; (ii) which modifications to apply to models before simulation; (iii) which simulation procedures to run on each model; (iv) how to post-process the data; and (v) how these results should be plotted and reported. SED-ML Level 1 Version 1 (L1V1) implemented support for the encoding of basic time course simulations. SED-ML L1V2 added support for more complex types of simulations, specifically repeated tasks and chained simulation procedures. SED-ML L1V3 extends L1V2 by means to describe which datasets and subsets thereof to use within a simulation experiment.

  1. Exploring Students' Flow Experiences in Business Simulation Games

    Science.gov (United States)

    Buil, I.; Catalán, S.; Martínez, E.

    2018-01-01

    Business simulation games are a motivational and engaging tool for teaching business management. However, relatively little is known about what factors contribute to their success. This study explores the role of flow experienced while using business simulation games. Specifically, this research investigates the influence of challenge, skills,…

  2. Simulation framework and XML detector description for the CMS experiment

    CERN Document Server

    Arce, P; Boccali, T; Case, M; de Roeck, A; Lara, V; Liendl, M; Nikitenko, A N; Schröder, M; Strässner, A; Wellisch, H P; Wenzel, H

    2003-01-01

    Currently CMS event simulation is based on GEANT3 while the detector description is built from different sources for simulation and reconstruction. A new simulation framework based on GEANT4 is under development. A full description of the detector is available, and the tuning of the GEANT4 performance and the checking of the ability of the physics processes to describe the detector response is ongoing. Its integration on the CMS mass production system and GRID is also currently under development. The Detector Description Database project aims at providing a common source of information for Simulation, Reconstruction, Analysis, and Visualisation, while allowing for different representations as well as specific information for each application. A functional prototype, based on XML, is already released. Also examples of the integration of DDD in the GEANT4 simulation and in the reconstruction applications are provided.

  3. Application of 2-D Simulations to Z-Pinch Experiment Design and Analysis

    International Nuclear Information System (INIS)

    Peterson, D.L.; Bowers, R.L.; Matuska, W.; Chandler, G.A.; Deeney, C.; Derzon, M.S.; Matzen, M.K.; Mock, R.C.; Nash, T.J.; Sanford, T.W.L.; Spielman, R.B.; Struve, K.W.

    1998-01-01

    The successful 2-D simulations of z-pinch experiments (reproducing such features as the measured experimental current drive, radiation pulse shape, peak power and total radiated energy) can lead to a better understanding of the underlying physics in z-pinch implosions and to the opportunity to use such simulations in the analysis of experimental data and in the design of new experiments. Such use has been made with LANL simulations of experiments on the Sandia Saturn and Z accelerators. Applications have included ''vacuum'' and ''dynamic'' hohlraum experiments; variations in mass, radius and length; and ''nested'' array configurations. Notable examples include the explanation of the power/length results in reduced length pinches and the prediction of the current best power and pulsewidth nested array experiment. Examples of circumstances where the simulation results do not match the experiments will be given along with a discussion of opportunities for improved simulation results

  4. NPP training simulators in Hungary experience in development and utilization

    International Nuclear Information System (INIS)

    Janosy, J.S.

    1996-01-01

    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

  5. Determining material parameters using phase-field simulations and experiments

    DEFF Research Database (Denmark)

    Zhang, Jin; Poulsen, Stefan O.; Gibbs, John W.

    2017-01-01

    A method to determine material parameters by comparing the evolution of experimentally determined 3D microstructures to simulated 3D microstructures is proposed. The temporal evolution of a dendritic solid-liquid mixture is acquired in situ using x-ray tomography. Using a time step from these data...... as an initial condition in a phase-field simulation, the computed structure is compared to that measured experimentally at a later time. An optimization technique is used to find the material parameters that yield the best match of the simulated microstructure to the measured microstructure in a global manner...

  6. Simulations of the Ondine experiment with the solitude code; Simulations de l`experience Ondine a l`aide du code solitude

    Energy Technology Data Exchange (ETDEWEB)

    Gouard, P.; Gardelle, J.

    1992-11-01

    A new version of the SOLITUDE code, including an axial magnetic field and a cylindrical waveguide, is presented. It allows to simulate the ONDINE experiment at CESTA and to study the effects and behaviour of an actual electron beam in a Free Electron Laser amplifier experiment.

  7. Blast Load Simulator Experiments for Computational Model Validation Report 3

    Science.gov (United States)

    2017-07-01

    establish confidence in the simulation results specific to their intended use. One method for providing experimental data for computational model...walls, to higher blast pressures required to evaluate the performance of protective construction methods . Figure 1. ERDC Blast Load Simulator (BLS... Instrumentation included 3 pressure gauges mounted on the steel calibration plate, 2 pressure gauges mounted in the wall of the BLS, and 25 pressure gauges

  8. Statistics for comparison of simulations and experiments of flow of blood cells*

    Directory of Open Access Journals (Sweden)

    Bachratá K.

    2017-01-01

    Full Text Available In this article we propose statistical method for comparison of simulation and real biological experiments of elastic objects moving in fluid. Our work is focused on future optimization of microfluidic devices used for capture of circulating tumor cells from blood samples. Since the design optimization using biological experiments is both time consuming and expensive, in silico experiments with a broad spectrum of complex and computationally simulations are intensely performed. Necessary verification if simulation models, hitherto mainly realised by comparision of individual cells properties must be extended to more complex simulations. We present our first results with characteristics designed for this purpose.

  9. Low energy and low fluence helium implantations in tungsten: Molecular dynamics simulations and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pentecoste, L. [GREMI, UMR7344 CNRS Université d’Orléans BP6744, 45067 Orléans Cedex 2 (France); Brault, P., E-mail: pascal.brault@univ-orleans.fr [GREMI, UMR7344 CNRS Université d’Orléans BP6744, 45067 Orléans Cedex 2 (France); Thomann, A.-L., E-mail: anne-lise.thomann@univ-orleans.fr [GREMI, UMR7344 CNRS Université d’Orléans BP6744, 45067 Orléans Cedex 2 (France); Desgardin, P. [CEMHTI, UPR3079 CNRS, 1D Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2 (France); Lecas, T. [GREMI, UMR7344 CNRS Université d’Orléans BP6744, 45067 Orléans Cedex 2 (France); Belhabib, T.; Barthe, M.-F.; Sauvage, T. [CEMHTI, UPR3079 CNRS, 1D Avenue de la Recherche Scientifique, 45071 Orléans Cedex 2 (France)

    2016-03-15

    300 eV Helium implantation process into tungsten at 300 K has been studied with molecular dynamic simulations (MD). Predicted retention doses were compared to that obtained from experiments performed in equivalent conditions. A saturation phenomenon of the helium retention was evidenced for a number of impinging He atoms and a retention dose similar in both, experiments and simulations. From MD simulations it is learnt that observed Helium diffusion, formation and coalescence of clusters are the phenomena leading to the flaking of the substrate. These processes could explain the saturation of the Helium retention observed experimentally at low energies. - Highlights: • MD simulations give He retention rate decreasing with increasing incident He number. • MD simulations reveal He saturation level in W close to experiments. • MD simulations show W flaking due to He accumulation. • MD simulations show stratification phenomena of the He depth distribution in W.

  10. Shower library technique for fast simulation of showers in calorimeters of the H1 experiment

    International Nuclear Information System (INIS)

    Raičević, N.; Glazov, A.; Zhokin, A.

    2013-01-01

    Fast simulation of showers in calorimeters is very important for particle physics analysis since shower simulation typically takes significant amount of the simulation time. At the same time, a simulation must reproduce experimental data in the best possible way. In this paper, a fast simulation of showers in two calorimeters of the H1 experiment is presented. High speed and good quality of shower simulation is achieved by using a shower library technique in which the detector response is simulated using a collection of stored showers for different particle types and topologies. The library is created using the GEANT programme. The fast simulation based on shower library is compared to the data collected by the H1 experiment

  11. Fourth Convection and Moisture Experiment ER2 MODIS Airborne Simulator

    Data.gov (United States)

    National Aeronautics and Space Administration — The Convection And Moisture EXperiment (CAMEX) 4 focused on the study of tropical cyclone (hurricane) development, tracking, intensification, and landfalling impacts...

  12. Simulating the Beam-line at CERN's ISOLDE Experiment

    CERN Document Server

    McGrath, Casey

    2013-01-01

    Maximizing the optical matching along portions of the ISOLDE beam-line and automating this procedure will make it easier for scientists to determine what the strengths of the electrical elds of each beam-line element should be in order to reduce particle loss. Simulations are run using a program called MAD-X, however, certain issues were discovered that hindered an immediate success of the simulations. Specifically, the transfer matrices for electrostatic components like the switchyards, kickers, and electric quadrupoles were missing from the original coding. The primary aim of this project was to design these components using AutoCAD and then extract the transfer matrices using SIMION. Future work will then implement these transfer matrices into the MAD-X code to make the simulations of the beam-line more accurate.

  13. An obstetric simulation experience in an undergraduate nursing curriculum.

    Science.gov (United States)

    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.

  14. Transverse ratchet effect and superconducting vortices: simulation and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dinis, L; Parrondo, J M R [Grupo Interdisciplinar de Sistemas Complejos (GISC) and Departamento de Fisica Atomica, Nuclear y Molecular, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Perez de Lara, D; Gonzalez, E M; Vicent, J L [Departamento de Fisica de Materiales, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Anguita, J V [Instituto de Microelectronica de Madrid, Consejo Superior de Investigaciones CientIficas, Tres Cantos E-28760 (Spain)], E-mail: ldinis@fis.ucm.es

    2009-07-15

    A transverse ratchet effect has been measured in magnetic/superconducting hybrid films fabricated by electron beam lithography and magnetron sputtering techniques. The samples are Nb films grown on top of an array of Ni nanotriangles. Injecting an ac current parallel to the triangle reflection symmetry axis yields an output dc voltage perpendicular to the current, due to a net motion of flux vortices in the superconductor. The effect is reproduced by numerical simulations of vortices as Langevin particles with realistic parameters. Simulations provide an intuitive picture of the ratchet mechanism, revealing the fundamental role played by the random intrinsic pinning of the superconductor.

  15. Use of simulators in operative dental education: experience in ...

    African Journals Online (AJOL)

    Background: Though the use of simulators in operative dentistry is not new, the teaching and learning practices that take place during clinical sessions in skills laboratories are rarely reported. This study was designed to determine the current practices relating to teaching and learning of dental clinical skills in southern ...

  16. Computer Simulations for Lab Experiences in Secondary Physics

    Science.gov (United States)

    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…

  17. Event-based Simulation Model for Quantum Optics Experiments

    NARCIS (Netherlands)

    De Raedt, H.; Michielsen, K.; Jaeger, G; Khrennikov, A; Schlosshauer, M; Weihs, G

    2011-01-01

    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

  18. Enhancing Lean Manufacturing Learning Experience through Hands-On Simulation

    Science.gov (United States)

    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…

  19. Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation

    Science.gov (United States)

    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.

  20. Good experiences with interactive temporal bone surgical simulator

    DEFF Research Database (Denmark)

    Andersen, Steven A W; Mikkelsen, Peter Trier; Noe, Karsten Ostergaard

    2014-01-01

    time. In a multilingual user interface the integrated tutor function provides stepwise instructions during drilling through an intuitive, volumetric approach. A censor function draws on metrics derived from the simulator to provide instant and summary feedback for the user. The VES can be downloaded...

  1. Audio-haptic interaction in simulated walking experiences

    DEFF Research Database (Denmark)

    Serafin, Stefania

    2011-01-01

    In this paper an overview of the work conducted on audio-haptic physically based simulation and evaluation of walking is provided. This work has been performed in the context of the Natural Interactive Walking (NIW) project, whose goal is to investigate possibilities for the integrated and interc...

  2. Use of simulators in operative dental education: experience in ...

    African Journals Online (AJOL)

    Abstract: Background: Though the use of simulators in operative dentistry is not new, the teaching and learning practices that take place during clinical sessions in skills laboratories are rarely reported. This study was designed to determine the current prac- tices relating to teaching and learning of dental clinical skills in ...

  3. Utilization of the Nursing Process to Foster Clinical Reasoning During a Simulation Experience

    Directory of Open Access Journals (Sweden)

    Amanda Lambie

    2015-11-01

    Full Text Available Nursing practice includes complex reasoning and multifaceted decision making with minimal standardized guidance in how to evaluate this phenomenon among nursing students. Learning outcomes related to the clinical reasoning process among novice baccalaureate nursing students during a simulation experience were evaluated. Nursing process records were utilized to evaluate and foster the development of clinical reasoning in a high-fidelity medical-surgical simulation experience. Students were unable to describe and process pertinent patient information appropriately prior to the simulation experience. Students’ ability to identify pertinent patient cues and plan appropriate patient care improved following the simulation. The learning activity afforded a structured opportunity to identify cues, prioritize the proper course of nursing interventions, and engage in collaboration among peers. The simulation experience provides faculty insight into the students’ clinical reasoning processes, while providing students with a clear framework for successfully accomplishing learning outcomes.

  4. MODIS Airborne Simulator Terra-aqua eXperiment 2002

    Data.gov (United States)

    National Aeronautics and Space Administration — The Terra-aqua eXperiment 2002 (TX-2002) was conducted from the former Kelly AFB in San Antonio, Texas from November 20 to December 13, 2002 to assess MODerate...

  5. Development of a helicon ion source: Simulations and preliminary experiments

    Science.gov (United States)

    Afsharmanesh, M.; Habibi, M.

    2018-03-01

    In the present context, the extraction system of a helicon ion source has been simulated and constructed. Results of the ion source commissioning at up to 20 kV are presented as well as simulations of an ion beam extraction system. Argon current of more than 200 μA at up to 20 kV is extracted and is characterized with a Faraday cup and beam profile monitoring grid. By changing different ion source parameters such as RF power, extraction voltage, and working pressure, an ion beam with current distribution exhibiting a central core has been detected. Jump transition of ion beam current emerges at the RF power near to 700 W, which reveals that the helicon mode excitation has reached this power. Furthermore, measuring the emission line intensity of Ar ii at 434.8 nm is the other way we have used for demonstrating the mode transition from inductively coupled plasma to helicon. Due to asymmetrical longitudinal power absorption of a half-helix helicon antenna, it is used for the ion source development. The modeling of the plasma part of the ion source has been carried out using a code, HELIC. Simulations are carried out by taking into account a Gaussian radial plasma density profile and for plasma densities in range of 1018-1019 m-3. Power absorption spectrum and the excited helicon mode number are obtained. Longitudinal RF power absorption for two different antenna positions is compared. Our results indicate that positioning the antenna near to the plasma electrode is desirable for the ion beam extraction. The simulation of the extraction system was performed with the ion optical code IBSimu, making it the first helicon ion source extraction designed with the code. Ion beam emittance and Twiss parameters of the ellipse emittance are calculated at different iterations and mesh sizes, and the best values of the mesh size and iteration number have been obtained for the calculations. The simulated ion beam extraction system has been evaluated using optimized parameters such

  6. Track Simulation and Reconstruction in the ATLAS experiment

    CERN Document Server

    Salzburger, Andreas; Elsing, Markus

    The reconstruction and simulation of particle trajectories is an inevitable part of the analysis strate- gies for data taken with the ATLAS detector. Many aspects and necessary parts of a high-quality track reconstruction will be presented and discussed in this work. At first, the technical realisation of the data model and the reconstruction geometry will be given; the reconstruction geometry is charac- terised by a newly developed navigation model and an automated procedure for the synchronisation of the detailed simulation geometry description with the simplified reconstruction geometry model, which allows a precise description of the tracker material in track reconstruction. Both components help the coherent and fast integration of material effects in a newly established track extrapolation package, that is discussed in the following. The extrapolation engine enables a highly precise trans- port of the track parameterisation and the associated covariances through the complex magnetic field and the detec...

  7. Transport phenomena in RTP: experiment and numerical simulations

    Science.gov (United States)

    Thyagaraja, A.; de Baar, M. R.; Knight, P.; Hogeweij, G. M. D.; Min, E.

    2002-11-01

    CUTIE (a computer model to simulate saturated 2 fluid electromagnetic global turbulence) is used to simulate the transition from an Ohmic to an RTP (circular cross-section, R=0.72m, a=0.16 m) type-D discharge. This is a discharge with dominant, off-axis ECH in which steady state hollow temperature profiles are observed. The dynamics of the q-profile, the bootstrap current, the turbulence drive terms, the E × B flow and the dynamo terms will be followed. The numerical results will be compared with the experimental observations. In particular, we will show that CUTIE positions the barriers near simple rational q values, naturally generates advective transport to support off-axis maxima in Te and produces off-axis MHD events similar to what has been observed in RTP.

  8. Simulations and experiments on polarization squeezing in optical fiber

    DEFF Research Database (Denmark)

    Corney, J.F.; Heersink, J.; Dong, R.

    2008-01-01

    We investigate polarization squeezing of ultrashort pulses in optical fiber, over a wide range of input energies and fiber lengths. Comparisons are made between experimental data and quantum dynamical simulations to find good quantitative agreement. The numerical calculations, performed using both...... effects cause a marked deterioration of squeezing at higher energies and longer fiber lengths. We also calculate the optimum fiber length for maximum squeezing....

  9. Simulation of Top Quark Production for the ATLAS Experiment

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00352736; The ATLAS collaboration

    2016-01-01

    The Monte Carlo setups used by ATLAS to model the $t\\bar{t}$ and single-top production in 13 TeV pp collisions are described. The performance of different event generators is assessed by comparing measurements at 7 TeV, 8 TeV and 13 TeV to predictions from simulated data. The evaluation of systematic uncertainties and the dependence of generator predictions on the tuning parameters are also discussed.

  10. RELAP4/MOD-5-CEA pump coastdown experiment simulation

    International Nuclear Information System (INIS)

    Borges, R.C.; Freitas, R.L.

    1988-07-01

    Since is important the theoretical-experimental comparison to evaluate the computer codes, these paper presents the simulation with RELAP4/MOD5 Code of a loss of power energy in the pump of the ''Circuito Experimental de Agua-CEA''. From the results attained, the existing models in the Code showed to be very satisfatory quantitative and qualitative behavior of the attained experimental results. (author) [pt

  11. Blast Load Simulator Experiments for Computational Model Validation: Report 1

    Science.gov (United States)

    2016-08-01

    to 2 psi) related to failures of conventional annealed glass and hollow concrete masonry unit walls. It can also simulate higher blast pressures for...Army, Air Force, Navy , and De- fense Special Weapons Agency 1998, Hyde 2003) calculations were con- ducted to produce a waveform that matched both peak...the structures located downstream of the cascade section of the BLS. ERDC/GSL TR-16-27 26 References Department of the Army, Air Force, Navy

  12. 'Odontologic dosimetric card' experiments and simulations using Monte Carlo methods

    International Nuclear Information System (INIS)

    Menezes, C.J.M.; Lima, R. de A.; Peixoto, J.E.; Vieira, J.W.

    2008-01-01

    The techniques for data processing, combined with the development of fast and more powerful computers, makes the Monte Carlo methods one of the most widely used tools in the radiation transport simulation. For applications in diagnostic radiology, this method generally uses anthropomorphic phantoms to evaluate the absorbed dose to patients during exposure. In this paper, some Monte Carlo techniques were used to simulation of a testing device designed for intra-oral X-ray equipment performance evaluation called Odontologic Dosimetric Card (CDO of 'Cartao Dosimetrico Odontologico' in Portuguese) for different thermoluminescent detectors. This paper used two computational models of exposition RXD/EGS4 and CDO/EGS4. In the first model, the simulation results are compared with experimental data obtained in the similar conditions. The second model, it presents the same characteristics of the testing device studied (CDO). For the irradiations, the X-ray spectra were generated by the IPEM report number 78, spectrum processor. The attenuated spectrum was obtained for IEC 61267 qualities and various additional filters for a Pantak 320 X-ray industrial equipment. The results obtained for the study of the copper filters used in the determination of the kVp were compared with experimental data, validating the model proposed for the characterization of the CDO. The results shower of the CDO will be utilized in quality assurance programs in order to guarantee that the equipment fulfill the requirements of the Norm SVS No. 453/98 MS (Brazil) 'Directives of Radiation Protection in Medical and Dental Radiodiagnostic'. We conclude that the EGS4 is a suitable code Monte Carlo to simulate thermoluminescent dosimeters and experimental procedures employed in the routine of the quality control laboratory in diagnostic radiology. (author)

  13. Experiment and Simulation Study on the Amorphous Silicon Photovoltaic Walls

    Directory of Open Access Journals (Sweden)

    Wenjie Zhang

    2014-01-01

    Full Text Available Based on comparative study on two amorphous silicon photovoltaic walls (a-Si PV walls, the temperature distribution and the instant power were tested; and with EnergyPlus software, similar models of the walls were built to simulate annual power generation and air conditioning load. On typical sunshine day, the corresponding position temperature of nonventilated PV wall was generally 0.5~1.5°C higher than that of ventilated one, while the power generation was 0.2%~0.4% lower, which was consistent with the simulation results with a difference of 0.41% in annual energy output. As simulation results, in summer, comparing the PV walls with normal wall, the heat per unit area of these two photovoltaic walls was 5.25 kWh/m2 (nonventilated and 0.67 kWh/m2 (ventilated higher, respectively. But in winter the heat loss of nonventilated one was smaller, while ventilated PV wall was similar to normal wall. To annual energy consumption of heating and cooling, the building with ventilated PV wall and normal wall was also similar but slightly better than nonventilated one. Therefore, it is inferred that, at low latitudes, such as Zhuhai, China, air gap ventilation is suitable, while the length to thickness ratio of the air gap needs to be taken into account.

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

    Science.gov (United States)

    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.

  15. Nucleation and solidification of thin walled ductile iron - Experiments and numerical simulation

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2005-01-01

    Investigation of solidification of thin walled ductile cast iron has been performed based on experiments and numerical simulation. The experiments were based on temperature and microstructure examination. Results of the experiments have been compared with a 1-D numerical solidification model...

  16. Virtual experiments: the ultimate aim of neutron ray-tracing simulations

    DEFF Research Database (Denmark)

    Lefmann, Kim; Willendrup, Peter Kjær; Udby, Linda

    2008-01-01

    We define a virtual neutron experiment as a complete simulation of an experiment, from source over sample to detector. The virtual experiment (VE) will ideally interface with the instrument control software for the input and with standard data analysis packages for the virtual data output. Virtua...

  17. On the computer simulation of the EPR-Bohm experiment

    International Nuclear Information System (INIS)

    McGoveran, D.O.; Noyes, H.P.; Manthey, M.J.

    1988-12-01

    We argue that supraluminal correlation without supraluminal signaling is a necessary consequence of any finite and discrete model for physics. Every day, the commercial and military practice of using encrypted communication based on correlated, pseudo-random signals illustrates this possibility. All that is needed are two levels of computational complexity which preclude using a smaller system to detect departures from ''randomness'' in the larger system. Hence the experimental realizations of the EPR-Bohm experiment leave open the question of whether the world of experience is ''random'' or pseudo-random. The latter possibility could be demonstrated experimentally if a complexity parameter related to the arm length and switching time in an Aspect-type realization of the EPR-Bohm experiment is sufficiently small compared to the number of reliable total counts which can be obtained in practice. 6 refs

  18. Development of a research simulator for the study of human factors and experiments

    International Nuclear Information System (INIS)

    Kawano, R.; Shibuya, S.

    1999-01-01

    A research simulator of nuclear power plant for Human Factors was developed. It simulates the behaviors of the 1100MWe BWR nuclear power plant and has almost same functions ant scope of the simulation as a full-scope training simulator. Physical models installed in the system enable us to execute experiments with multi-malfunction scenario. A severe accident simulation package replaces the running simulation code when the maximum core temperature exceeds 1200 deg C and the core approaches meltdown conditions. The central control panel was simulated by soft panels, indicator and operational switches on the panels by computer graphics, displayed on 22 console boxes containing CRT. The introduction of soft panels and EWSs connected with LAN accomplished flexibility and extendibility. Some experiments by using the simulator were executed and the system has been improved based on the experience from the experiments. It is important to evaluate the effectiveness of any new system by using an actual plant size research simulator before its practical application to keep steady and safe operation of nuclear power plants. (author)

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

    Science.gov (United States)

    Minton, T. K.; Cline, J. A.; Braunstein, M.

    2002-01-01

    Fast, pulsed atomic oxygen sources are a key tool in ground-based investigations of spacecraft contamination and surface erosion effects. These technically challenging ground-based studies provide a before and after picture of materials under low-earth-orbit (LEO) conditions. It would be of great interest to track in real time the pulsed flux from the source to the surface sample target and beyond in order to characterize the population of atoms and molecules that actually impact the surface and those that make it downstream to any coincident detectors. We have performed simulations in order to provide such detailed descriptions of these ground-based measurements and to provide an assessment of their correspondence to the actual LEO environment. Where possible we also make comparisons to measured fluxes and erosion yields. To perform the calculations we use a detailed description of a measurement beam and surface geometry based on the W, pulsed apparatus at Montana State University. In this system, a short pulse (on the order of 10 microseconds) of an O/O2 beam impacts a flat sample about 40 cm downstream and slightly displaced &om the beam s central axis. Past this target, at the end of the beam axis is a quadrupole mass spectrometer that measures the relative in situ flux of 0102 to give an overall normalized erosion yield. In our simulations we use the Direct Simulation Monte Carlo (DSMC) method, and track individual atoms within the atomic oxygen pulse. DSMC techniques are typically used to model rarefied (few collision) gas-flows which occur at altitudes above approximately 110 kilometers. These techniques are well suited for the conditions here, and multi-collision effects that can only be treated by this or a similar technique are included. This simulation includes collisions with the surface and among gas atoms that have scattered from the surface. The simulation also includes descriptions of the velocity spread and spatial profiles of the O/O2 beam

  20. Does perception of usefulness of arthroscopic simulators differ with levels of experience?

    Science.gov (United States)

    Tuijthof, Gabriëlle J M; Visser, P; Sierevelt, Inger N; Van Dijk, C Niek; Kerkhoffs, Gino M M J

    2011-06-01

    Some commercial simulators are available for training basic arthroscopic skills. However, it is unclear if these simulators allow training for their intended purposes and whether the perception of usefulness relates to level of experience. We addressed the following questions: (1) Do commercial simulators have construct (times to perform tasks) and face validity (realism), and (2) is the perception of usefulness (educational value and user-friendliness) related to level of experience? We evaluated two commercially available virtual reality simulators (Simulators A and B) and recruited 11 and nine novices (no arthroscopies), four and four intermediates (one to 59 arthroscopies), and seven and nine experts (> 60 arthroscopies) to test the devices. To assess construct validity, we recorded the median time per experience group for each of five repetitions of one identical navigation task. To assess face validity, we used a questionnaire to judge up to three simulator characteristic tasks; the questionnaire asked about the realism, perception of educational value, and perception of user-friendliness. We observed partial construct validity for Simulators A and B and considered face validity satisfactory for both simulators for simulating the outer appearance and human joint, but barely satisfactory for the instruments. Simulators A and B had equal educational value according to the participants. User-friendliness was judged better for Simulator B although both were graded satisfactory. The perception of usefulness did not differ with level of experience. Our observations suggest training on either simulator is reasonable preparation for real-life arthroscopy, although there is room for improvement for both simulators.

  1. Use of simulators in operative dental education: experience in ...

    African Journals Online (AJOL)

    Department of Restorative Dentistry, College of Health Sciences, University of Port Harcourt, Port Harcourt,. Rivers State, Nigeria. 2. Department of Child Oral Health, College .... Table 2: Students' views and learning experiences in dental operative clinical skills laboratory N=261 ..... romah C, Otieno-Nyunya B, Morahan PS.

  2. Evaluation of Surface Runoff Generation Processes Using a Rainfall Simulator: A Small Scale Laboratory Experiment

    Science.gov (United States)

    Danáčová, Michaela; Valent, Peter; Výleta, Roman

    2017-12-01

    Nowadays, rainfall simulators are being used by many researchers in field or laboratory experiments. The main objective of most of these experiments is to better understand the underlying runoff generation processes, and to use the results in the process of calibration and validation of hydrological models. Many research groups have assembled their own rainfall simulators, which comply with their understanding of rainfall processes, and the requirements of their experiments. Most often, the existing rainfall simulators differ mainly in the size of the irrigated area, and the way they generate rain drops. They can be characterized by the accuracy, with which they produce a rainfall of a given intensity, the size of the irrigated area, and the rain drop generating mechanism. Rainfall simulation experiments can provide valuable information about the genesis of surface runoff, infiltration of water into soil and rainfall erodibility. Apart from the impact of physical properties of soil, its moisture and compaction on the generation of surface runoff and the amount of eroded particles, some studies also investigate the impact of vegetation cover of the whole area of interest. In this study, the rainfall simulator was used to simulate the impact of the slope gradient of the irrigated area on the amount of generated runoff and sediment yield. In order to eliminate the impact of external factors and to improve the reproducibility of the initial conditions, the experiments were conducted in laboratory conditions. The laboratory experiments were carried out using a commercial rainfall simulator, which was connected to an external peristaltic pump. The pump maintained a constant and adjustable inflow of water, which enabled to overcome the maximum volume of simulated precipitation of 2.3 l, given by the construction of the rainfall simulator, while maintaining constant characteristics of the simulated precipitation. In this study a 12-minute rainfall with a constant intensity

  3. 2-D Clinostat for Simulated Microgravity Experiments with Arabidopsis Seedlings

    Science.gov (United States)

    Wang, Hui; Li, Xugang; Krause, Lars; Görög, Mark; Schüler, Oliver; Hauslage, Jens; Hemmersbach, Ruth; Kircher, Stefan; Lasok, Hanna; Haser, Thomas; Rapp, Katja; Schmidt, Jürgen; Yu, Xin; Pasternak, Taras; Aubry-Hivet, Dorothée; Tietz, Olaf; Dovzhenko, Alexander; Palme, Klaus; Ditengou, Franck Anicet

    2016-04-01

    Ground-based simulators of microgravity such as fast rotating 2-D clinostats are valuable tools to study gravity related processes. We describe here a versatile g-value-adjustable 2-D clinostat that is suitable for plant analysis. To avoid seedling adaptation to 1 g after clinorotation, we designed chambers that allow rapid fixation. A detailed protocol for fixation, RNA isolation and the analysis of selected genes is described. Using this clinostat we show that mRNA levels of LONG HYPOCOTYL 5 (HY5), MIZU-KUSSEI 1 (MIZ1) and microRNA MIR163 are down-regulated in 5-day-old Arabidopsis thaliana roots after 3 min and 6 min of clinorotation using a maximal reduced g-force of 0.02 g, hence demonstrating that this 2-D clinostat enables the characterization of early transcriptomic events during root response to microgravity. We further show that this 2-D clinostat is able to compensate the action of gravitational force as both gravitropic-dependent statolith sedimentation and subsequent auxin redistribution (monitoring D R5 r e v :: G F P reporter) are abolished when plants are clinorotated. Our results demonstrate that 2-D clinostats equipped with interchangeable growth chambers and tunable rotation velocity are suitable for studying how plants perceive and respond to simulated microgravity.

  4. Acoustic improvement on two lecture auditoria: Simulation and experiment

    Directory of Open Access Journals (Sweden)

    Soha Eldakdoky

    2017-03-01

    Full Text Available Based on the commonly used indicators for speech intelligibility, this work acoustically evaluates the two largest auditoria in the Faculty of Engineering, Helwan University, Cairo, Egypt, using experimental and digital simulation techniques. Design treatments were also suggested to improve the acoustic performance of the auditoria, where the impact of these treatments was checked using the simulation as well. The models that were analysed using the CATT software were first validated utilizing the results of the field work in the unoccupied rooms. The results showed that the acoustic quality of the two auditoria are far from the optimal conditions due to their improper acoustic characteristics and the high noise levels as well. The results of improvement proposals showed that altering the ceiling shape and adding efficient absorptive materials to the rear surfaces successfully reduced the excessive reverberation time to the optimal values, increased the early reflections and eliminated the shadow zones. In addition, decreasing the noise levels by 20 dB due to improving the window insulation noticeably improved the speech intelligibility at all receivers.

  5. Application of simulation experiments to fusion materials development

    International Nuclear Information System (INIS)

    Nolfi, F.V. Jr.; Li, C.Y.

    1978-01-01

    One of the major problems in the development of structural alloys for use in magnetic fusion reactors (MFRs) is the lack of suitable materials testing facilities. This is because operating fusion reactors, even of the experimental size, do not exist. A primary task in the early stages of MFR alloy development will be to adapt currently available irradiation facilities for use in materials development. Thus, it is generally recognized that, at least for the next ten years, studies of irradiation effects in an MFR environment on the microstructure and mechanical properties of structural materials must utilize ion and fission neutron simulations. Special problems will arise because, in addition to displacement damage, an MFR radiation environment will produce, in candidate structural materials, higher and more significant concentrations of gaseous nuclear transmutation products, e.g., helium and hydrogen, than found in a fast breeder reactor. These effects must be taken into account when simulation techniques are employed, since they impact heavily on irradiation microstructure development and, hence, mechanical properties

  6. Velocity measurement accuracy in optical microhemodynamics: experiment and simulation

    International Nuclear Information System (INIS)

    Chayer, Boris; Cloutier, Guy; L Pitts, Katie; Fenech, Marianne

    2012-01-01

    Micro particle image velocimetry (µPIV) is a common method to assess flow behavior in blood microvessels in vitro as well as in vivo. The use of red blood cells (RBCs) as tracer particles, as generally considered in vivo, creates a large depth of correlation (DOC), even as large as the vessel itself, which decreases the accuracy of the method. The limitations of µPIV for blood flow measurements based on RBC tracking still have to be evaluated. In this study, in vitro and in silico models were used to understand the effect of the DOC on blood flow measurements using µPIV RBC tracer particles. We therefore employed a µPIV technique to assess blood flow in a 15 µm radius glass tube with a high-speed CMOS camera. The tube was perfused with a sample of 40% hematocrit blood. The flow measured by a cross-correlating speckle tracking technique was compared to the flow rate of the pump. In addition, a three-dimensional mechanical RBC-flow model was used to simulate optical moving speckle at 20% and 40% hematocrits, in 15 and 20 µm radius circular tubes, at different focus planes, flow rates and for various velocity profile shapes. The velocity profiles extracted from the simulated pictures were compared with good agreement with the corresponding velocity profiles implemented in the mechanical model. The flow rates from both the in vitro flow phantom and the mathematical model were accurately measured with less than 10% errors. Simulation results demonstrated that the hematocrit (paired t tests, p = 0.5) and the tube radius (p = 0.1) do not influence the precision of the measured flow rate, whereas the shape of the velocity profile (p < 0.001) and the location of the focus plane (p < 0.001) do, as indicated by measured errors ranging from 3% to 97%. In conclusion, the use of RBCs as tracer particles makes a large DOC and affects the image processing required to estimate the flow velocities. We found that the current µPIV method is acceptable to estimate the flow rate

  7. Simulation Experiments: Better Data, Not Just Big Data

    Science.gov (United States)

    2014-12-01

    93943-5219, USA ABSTRACT Data mining tools have been around for several decades, but the term “big data” has only recently captured widespread...manipulate the environment to their advantage, by using irrigation, pest control, crop rotation, fertilizer, and more. Small-scale designed experiments let...instances tap the benefits of correlation.” But if the goal of analysis is to yield better outcomes via controlling or influencing the inputs, what could

  8. Colloids dragged through a polymer solution: experiment, theory and simulation

    OpenAIRE

    Gutsche, Christof; Kremer, Friedrich; Krüger, Matthias; Rauscher, Markus; Weeber, Rudolf; Harting, Jens

    2007-01-01

    We present micro-rheological measurments of the drag force on colloids pulled through a solution of lambda-DNA (used here as a monodisperse model polymer) with an optical tweezer. The experiments show a violation of the Stokes-Einstein relation based on the independently measured viscosity of the DNA solution: the drag force is larger than expected. We attribute this to the accumulation of DNA infront of the colloid and the reduced DNA density behind the colloid. This hypothesis is corroborat...

  9. Extracting Synthetic Multi-Cluster Platform Configurations from Grid'5000 for Driving Simulation Experiments

    OpenAIRE

    Suter , Frédéric; Casanova , Henri

    2007-01-01

    This report presents a collection of synthetic but realistic distributed computing platform configurations. These configurations are intended for simulation experiments in the study of parallel applications on multi-cluster platforms.

  10. First Experiments with the Simulation of Particulate Flows

    Energy Technology Data Exchange (ETDEWEB)

    Uhlmann, M.

    2003-07-01

    Several variants of a Eulerian-Lagrangian method for the simulation of particulate flows are implemented in a finite-difference framework. All methods have in common that they represent the presence of the solid fraction by means of artificial volume forces in the momentum equation of the fluid phase. Thereby, explicit griddling of the moving particles is avoided and a fixed grid can be used. The computations show that the direct forcing method (Kin et a/., 2001) is not adequate for a our purposes due to large oscillations in the hydro-dynamical forces. The immersed method of Pekin (2002) does provide accurate predictions of particle motion,however at the cost of a small time step. (Author) 33 refs.

  11. Monte Carlo simulation of the abBA experiment

    Science.gov (United States)

    Frlež, Emil

    2004-10-01

    The abBA collaboration proposes to conduct a program of precise measurements of neutron beta decay correlation coefficients a, b, A, and B at a cold neutron beam facility. We have performed studies of the energy and timing response of a pair of silicon detectors. To this end we have compared (i) the industry-standard SIMION 3D 7.0 program, and (ii) a GEANT4-based code with the addition of appropriate adiabatic invariants in simulating the propagation of the decay electrons and protons in the electromagnetic spectrometer. We use these results to examine the systematic effects and to determine the precision with which the physics parameters a, b, A, and B can be extracted in practice.

  12. A model ecosystem experiment and its computational simulation studies

    International Nuclear Information System (INIS)

    Doi, M.

    2002-01-01

    Simplified microbial model ecosystem and its computer simulation model are introduced as eco-toxicity test for the assessment of environmental responses from the effects of environmental impacts. To take the effects on the interactions between species and environment into account, one option is to select the keystone species on the basis of ecological knowledge, and to put it in the single-species toxicity test. Another option proposed is to put the eco-toxicity tests as experimental micro ecosystem study and a theoretical model ecosystem analysis. With these tests, the stressors which are more harmful to the ecosystems should be replace with less harmful ones on the basis of unified measures. Management of radioactive materials, chemicals, hyper-eutrophic, and other artificial disturbances of ecosystem should be discussed consistently from the unified view point of environmental protection. (N.C.)

  13. Characterizing Hypervelocity Impact Plasma Through Experiments and Simulations

    Science.gov (United States)

    Close, Sigrid; Lee, Nicolas; Fletcher, Alex; Nuttall, Andrew; Hew, Monica; Tarantino, Paul

    2017-10-01

    Hypervelocity micro particles, including meteoroids and space debris with masses produce a strong electromagnetic pulse (EMP) with a broad frequency spectrum. Subsequent plasma oscillations resulting from instabilities can also emit significant power and may be responsible for many reported satellite anomalies. We present theory and recent results from ground-based impact tests aimed at characterizing hypervelocity impact plasma. We also show results from particle-in-cell (PIC) and computational fluid dynamics (CFD) simulations that allow us to extend to regimes not currently possible with ground-based technology. We show that significant impact-produced radio frequency (RF) emissions occurred in frequencies ranging from VHF through L-band and that these emissions were highly correlated with fast (>20 km/s) impacts that produced a fully ionized plasma.

  14. [Spontaneous synchronous discharges in hippocampal slices. Simulation and experiment].

    Science.gov (United States)

    Dudkin, A O; Sbitnev, V I

    2000-01-01

    Chaotic oscillations of extracellular potential of field-type nerve tissues are simulated by a 2D coupled map lattice. These tissues, say, the fields of the hippocampus, are represented by neural mass sheets consisting of current sources. The relationship between the source-sink ensembles and the extracellular field potential at each discrete instant of time t = 1, 2, ... is described by a single-site map creating chaos. The 2D coupled map lattice is viewed as a network of diffusively coupled the maps creating spatiotemporal chaos. The conversion of chaotic oscillations into synchronous ones, which are typical for epileptiform discharges, is studied. The results obtained are in good agreement with those derived from hippocampal slices treated with picrotoxin.

  15. A consolidated process for software process simulation : State of the Art and Industry Experience

    OpenAIRE

    Ali, Nauman Bin; Petersen, Kai

    2012-01-01

    Software process simulation is a complex task and in order to conduct a simulation project practitioners require support through a process for software process simulation modelling (SPSM), including what steps to take and what guidelines to follow in each step. This paper provides a literature based consolidated process for SPSM where the steps and guidelines for each step are identified through a review of literature and are complemented by experience from using these recommendations in an a...

  16. Monte-Carlo simulation of hadronic showers. Part 1: Comparison with experiment

    International Nuclear Information System (INIS)

    Amatuni, Ts.A.; Mamidjanyan, E.A.; Sanossyan, Kh.N.

    1992-01-01

    Hadronic showers are simulated by the MARS 10 code and compared with various experimental results obtained at high-energy accelerators. Good agreement between the experiment and the simulations is observed. MARS 10 is a fast and reliable instrument for numerical studies of the average characteristics of hadronic showers. 16 refs

  17. Does Perception of Usefulness of Arthroscopic Simulators Differ with Levels of Experience?

    NARCIS (Netherlands)

    Tuijthof, Gabriëlle J. M.; Visser, P.; Sierevelt, Inger N.; van Dijk, C. Niek; Kerkhoffs, Gino M. M. J.

    2011-01-01

    Some commercial simulators are available for training basic arthroscopic skills. However, it is unclear if these simulators allow training for their intended purposes and whether the perception of usefulness relates to level of experience. We addressed the following questions: (1) Do commercial

  18. Using interactive model simulations in co-design : An experiment in urban design

    NARCIS (Netherlands)

    Steen, M.G.D.; Arendsen, J.; Cremers, A.H.M.; Vries, A. de; Jong, J.M.G. de; Koning, N.M. de

    2013-01-01

    This paper presents an experiment in which people performed a co-design task in urban design, using a multi-user touch table application with or without interactive model simulations. We hypothesised that using the interactive model simulations would improve communication and co-operation between

  19. Event-by-event simulation of a quantum delayed-choice experiment

    NARCIS (Netherlands)

    Donker, Hylke C.; De Raedt, Hans; Michielsen, Kristel

    2014-01-01

    The quantum delayed-choice experiment of Tang et al. (2012) is simulated on the level of individual events without making reference to concepts of quantum theory or without solving a wave equation. The simulation results are in excellent agreement with the quantum theoretical predictions of this

  20. FATRAS - A Novel Fast Track Simulation Engine for the ATLAS Experiment

    CERN Document Server

    Fleischmann, S; The ATLAS collaboration

    2010-01-01

    Monte Carlo simulation of the detector response is an inevitable part of any kind of analysis which is performed with data from the LHC experiments. These simulated data sets are needed with large statistics and high precision level, which makes their production a CPU-cost intensive task. ATLAS has thus concentrated on optimizing both full and fast detector simulation techniques to achieve this goal within the computing limits of the collaboration. At the early stages of data-taking, in particular, it is necessary to reprocess the Monte Carlo event samples continuously, while integrating adaptations to the simulation modules to improve the agreement with the data taken from the detector itself. We present a new, fast track simulation engine which establishes a full Monte Carlo simulation which is based on modules and the geometry of the ATLAS standard track reconstruction application. This is combined with a fast parametric-response simulation of the Calorimeter. This approach shows a high level of agreement ...

  1. Students’ Expectations and Experiences of Meaningful Simulation-Based Medical Education

    Directory of Open Access Journals (Sweden)

    Tuulikki Keskitalo

    2016-11-01

    Full Text Available This study aims to investigate students’ expectations and experiences of meaningful learning in simulation-based learning environments. We set the following research question: How do students’ experiences of meaningful simulation-based learning correspond to their expectations? The students’ (n = 87; male 51, female 36 pre- and post-questionnaires were analyzed using statistical methods. The results indicated that students’ expectations and experiences of meaningful learning were positive, and for most statements, there were statistically significant differences between the mean pre-questionnaire rating and the mean post-questionnaire rating, thereby indicating that students’ actual experiences of simulation-based learning were more positive than their expectations. Thus, students’ experiences exceeded their expectations.

  2. Tritium release experiments with CATS and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Munakata, Kenzo, E-mail: kenzo@gipc.akita-u.ac.jp [Faculty of Engineering and Resource Sciences, Akita University, Tegata-gakuen-cho 1-1, Akita 010-8502 (Japan); Wajima, Takaaki; Hara, Keisuke; Wada, Kohei [Faculty of Engineering and Resource Sciences, Akita University, Tegata-gakuen-cho 1-1, Akita 010-8502 (Japan); Takeishi, Toshiharu; Shinozaki, Yohei; Mochizuki, Kazuhiro; Katekari, Kenichi [Interdisciplinary Graduate School of Engineering Science, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581 (Japan); Kobayashi, Kazuhiro; Iwai, Yasunori; Hayashi, Takumi; Yamanishi, Toshihiko [Tritium Technology Group, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)

    2010-12-15

    In D-T fusion power plants, large amounts of tritium would be handled. Tritium is the radioisotope of protium, and is easily taken into the human body, and thus the behavior of tritium accidentally released in fusion power plants should be studied for the safety design and radioprotection of workers. Therefore, it is necessary to investigate the behavior of tritium released into large rooms with objectives, since complex flow fields should exist in such rooms and they could influence the ventilation of the air containing released tritium. Thus, tritium release experiments were conducted using Caisson Assembly for Tritium Safety Study (CATS) in TPL/JAEA. Some data were taken for tritium behavior in the ventilated area and response of tritium monitors. In the experiments, approximately 17 GBq of tritium was released into Caisson with the total volume of 12 m{sup 3}, and the room was ventilated at the rate of 12 m{sup 3}/h after release of tritium. It was found that placement of an objective in the vessel substantially affects decontamination efficiency. With regard to an experimental result, numerical calculation was performed and the experimental result and the result of numerical calculation were compared, which indicates that experimental results are qualitatively reproduced by numerical calculation. However, further R and D needs to be carried out for quantitative reproduction of the experimental results.

  3. Process of cracking in reinforced concrete beams (simulation and experiment

    Directory of Open Access Journals (Sweden)

    I. N. Shardakov

    2016-10-01

    Full Text Available The paper presents the results of experimental and theoretical investigations of the mechanisms of crack formation in reinforced concrete beams subjected to quasi-static bending. The boundary-value problem has been formulated in the framework of brittle fracture mechanics and solved using the finite-element method. Numerical simulation of the vibrations of an uncracked beam and a beam with cracks of different size serves to determine the pattern of changes in the spectrum of eigenfrequencies observed during crack evolution. A series of sequential quasi-static 4-point bend tests leading to the formation of cracks in a reinforced concrete beam were performed. At each loading step, the beam was subjected to an impulse load to induce vibrations. Two stages of cracking were detected. During the first stage the nonconservative process of deformation begins to develope, but has not visible signs. The second stage is an active cracking, which is marked by a sharp change in eingenfrequencies. The boundary of a transition from one stage to another is well registered. The vibration behavior was examined for the ordinary concrete beams and the beams strengthened with a carbon-fiber polymer. The obtained results show that the vibrodiagnostic approach is an effective tool for monitoring crack formation and assessing the quality of measures aimed at strengthening concrete structures

  4. Taylor bubbles at high viscosity ratios: experiments and numerical simulations

    Science.gov (United States)

    Hewakandamby, Buddhika; Hasan, Abbas; Azzopardi, Barry; Xie, Zhihua; Pain, Chris; Matar, Omar

    2015-11-01

    The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube, often occurring in gas-liquid slug flows in many industrial applications, particularly oil and gas production. The objective of this study is to investigate the fluid dynamics of three-dimensional Taylor bubble rising in highly viscous silicone oil in a vertical pipe. An adaptive unstructured mesh modelling framework is adopted here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rising and reduce computational effort without sacrificing accuracy. The numerical framework consists of a mixed control volume and finite element formulation, a `volume of fluid'-type method for the interface-capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Experimental results for the Taylor bubble shape and rise velocity are presented, together with numerical results for the dynamics of the bubbles. A comparison of the simulation predictions with experimental data available in the literature is also presented to demonstrate the capabilities of our numerical method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  5. Performance analysis of bullet trajectory estimation: Approach, simulation, and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ng, L.C.; Karr, T.J.

    1994-11-08

    This paper describes an approach to estimate a bullet`s trajectory from a time sequence of angles-only observations from a high-speed camera, and analyzes its performance. The technique is based on fitting a ballistic model of a bullet in flight along with unknown source location parameters to a time series of angular observations. The theory is developed to precisely reconstruct, from firing range geometry, the actual bullet trajectory as it appeared on the focal plane array and in real space. A metric for measuring the effective trajectory track error is also presented. Detailed Monte-Carlo simulations assuming different bullet ranges, shot-angles, camera frame rates, and angular noise show that angular track error can be as small as 100 {mu}rad for a 2 mrad/pixel sensor. It is also shown that if actual values of bullet ballistic parameters were available, the bullet s source location variables, and the angles of flight information could also be determined.

  6. Mechanical behavior of ``living quicksand'': Simulation and Experiment

    Science.gov (United States)

    Kadau, Dirk; Herrmann, Hans J.; Andrade, José S.

    2009-06-01

    The nature and danger of quicksand has been disputed since a long time. Despite widespread belief that humans can be swallowed or even sucked in, engineers of soil mechanics have typically asserted that, since the density of sludge is larger than that of water, a person cannot fully submerge. We investigated a specific type of quicksand at the shore of drying lagoons. Cyanobacteria form an impermeable crust, giving the impression of stable ground. After breaking the crust a person rapidly sinks to the bottom of the field. We measured the shear strength of the material before and after perturbation and found a drastic change. The initial structure cannot be restored once it had collapsed, i.e. the material investigated shows a strong memory effect. We simulated a model for this type of quicksand in which we constructed a tenuous granular structure representing the unperturbed soil. The initial structure consists of cohesive disks put together by ballistic deposition and settled by gravity using Contact Dynamics. We study the material behavior by determining the shear strength of the model material and by penetration tests, i.e. pushing in an object, which leads to breaking of cohesive bonds. We investigate how deep the object can be pushed in and how well the intruder is captured by the material after it collapsed above the intruder. During the penetration process we measured the relation between the driving force and the resulting velocity of the intruder.

  7. Professors' and students' perceptions and experiences of computational simulations as learning tools

    Science.gov (United States)

    Magana de Leon, Alejandra De Jesus

    Computational simulations are becoming a critical component of scientific and engineering research, and now are becoming an important component for learning. This dissertation provides findings from a multifaceted research study exploring the ways computational simulations have been perceived and experienced as learning tools by instructors and students. Three studies were designed with an increasing focus on the aspects of learning and instructing with computational simulation tools. Study One used a student survey with undergraduate and graduate students whose instructors enhanced their teaching using online computational tools. Results of this survey were used to identify students' perceptions and experiences with these simulations as learning tools. The results provided both an evaluation of the instructional design and an indicator of which instructors were selected in Study Two. Study Two used a phenomenographic research design resulting in a two dimensional outcome space with six qualitatively different ways instructors perceived their learning outcomes associated with using simulation tools as part of students' learning experiences. Results from this work provide a framework for identifying major learning objectives to promote learning with computational simulation tools. Study Three used a grounded theory methodology to expand on instructors' learning objectives to include their perceptions of formative assessment and pedagogy. These perceptions were compared and contrasted with students' perceptions associated with learning with computational tools. The study is organized around three phases and analyzed as a collection of case studies focused on the instructors and their students' perceptions and experiences of computational simulations as learning tools. This third study resulted in a model for using computational simulations as learning tools. This model indicates the potential of integrating the computational simulation tools into formal learning

  8. Net-erosion profile model and simulation experiments

    International Nuclear Information System (INIS)

    Sagara, Akio

    2001-01-01

    Estimation of net-erosion profile is requisite for evaluating the lifetime of divertor plates under high heat and particle fluxes of fusion plasmas. As a reference in benchmark tests of numerical calculation codes, a self-consistent analytical solution is presented for a simplified divertor condition, wherein the magnetic field line is normal to the target plate and the ionization mean free path of sputtered particles is assumed constant. The primary flux profile of hydrogen and impurities are externally given as well as the return ratio of sputtered atoms to the target. In the direction along the divertor trace, all conditions are uniform. The analytical solution is compared with net-erosion experiments carried out using the Compact Helical System (CHS). The deposition profiles of Ti and O impurities are in very good agreement with the analytical predictions. Recent preliminary results observed on divertor plates in the Large Helical Device (LHD) are briefly presented. (author)

  9. Nanostructured Soft Matter Experiment, Theory, Simulation and Perspectives

    CERN Document Server

    Zvelindovsky, Andrei V

    2007-01-01

    This book provides an interdisciplinary overview of a new and broad class of materials under the unifying name Nanostructured Soft Matter. It covers materials ranging from short amphiphilic molecules to block copolymers, proteins, colloids and their composites, microemulsions and bio-inspired systems such as vesicles. The book considers several fundamental questions, including: how self-assembly of various soft materials with internal structure at the nanoscale can be understood, controlled and in future used in the newly emerging field of soft nanotechnology. The book offers readers a view on the subject from different perspectives, combining modern experimental approaches from physical chemistry and physics with various theoretical techniques from physics, mathematics and the most advanced computer modelling. It is the first book of this sort in the field. All chapters are written by leading international experts, bringing together experience from Canada, Germany, Great Britain, Japan, the Netherlands, Russ...

  10. National Fusion Collaboratory: Grid Computing for Simulations and Experiments

    Science.gov (United States)

    Greenwald, Martin

    2004-05-01

    The National Fusion Collaboratory Project is creating a computational grid designed to advance scientific understanding and innovation in magnetic fusion research by facilitating collaborations, enabling more effective integration of experiments, theory and modeling and allowing more efficient use of experimental facilities. The philosophy of FusionGrid is that data, codes, analysis routines, visualization tools, and communication tools should be thought of as network available services, easily used by the fusion scientist. In such an environment, access to services is stressed rather than portability. By building on a foundation of established computer science toolkits, deployment time can be minimized. These services all share the same basic infrastructure that allows for secure authentication and resource authorization which allows stakeholders to control their own resources such as computers, data and experiments. Code developers can control intellectual property, and fair use of shared resources can be demonstrated and controlled. A key goal is to shield scientific users from the implementation details such that transparency and ease-of-use are maximized. The first FusionGrid service deployed was the TRANSP code, a widely used tool for transport analysis. Tools for run preparation, submission, monitoring and management have been developed and shared among a wide user base. This approach saves user sites from the laborious effort of maintaining such a large and complex code while at the same time reducing the burden on the development team by avoiding the need to support a large number of heterogeneous installations. Shared visualization and A/V tools are being developed and deployed to enhance long-distance collaborations. These include desktop versions of the Access Grid, a highly capable multi-point remote conferencing tool and capabilities for sharing displays and analysis tools over local and wide-area networks.

  11. Nonlinear polarization of ionic liquids: theory, simulations, experiments

    Science.gov (United States)

    Kornyshev, Alexei

    2010-03-01

    Room temperature ionic liquids (RTILs) composed of large, often asymmetric, organic cations and simple or complex inorganic or organic anions do not freeze at ambient temperatures. Their rediscovery some 15 years ago is widely accepted as a ``green revolution'' in chemistry, offering an unlimited number of ``designer'' solvents for chemical and photochemical reactions, homogeneous catalysis, lubrication, and solvent-free electrolytes for energy generation and storage. As electrolytes they are non-volatile, some can sustain without decomposition up to 6 times higher voltages than aqueous electrolytes, and many are environmentally friendly. The studies of RTILs and their applications have reached a critical stage. So many of them can be synthesized - about a thousand are known already - their mixtures can further provide ``unlimited'' number of combinations! Thus, establishing some general laws that could direct the best choice of a RTIL for a given application became crucial; guidance is expected from theory and modelling. But for a physical theory, RTILs comprise a peculiar and complex class of media, the description of which lies at the frontier line of condensed matter theoretical physics: dense room temperature ionic plasmas with ``super-strong'' Coulomb correlations, which behave like glasses at short time-scale, but like viscous liquids at long-time scale. This talk will introduce RTILs to physicists and overview the current understanding of the nonlinear response of RTILs to electric field. It will focus on the theory, simulations, and experimental characterisation of the structure and nonlinear capacitance of the electrical double layer at a charged electrode. It will also discuss pros and contras of supercapacitor applications of RTILs.

  12. Transport phenomena in granular materials: Experiments and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ialali, P.; Sarkomaa, P. [Department of Energy and Environmental Engineering, Lappeenranta University of Technology, Lappeenranta (Finland); Mo Li [School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

    2007-07-01

    Granular materials are found in nature and in the technology. Common examples are sand, sugar, snow, synthetic powders, cement and soil. They are collections of individual solid grains with hybrid bulk properties so that they display both solid-like and fluid-like behaviors under various circumstances. Grains are interacting through collisions or contacts either with each other or with confining walls. The transport of mass, momentum and kinetic energy (not thermal energy) has been studied in deforming granular materials both theoretically and experimentally. In static granular media (no deformation), the distribution of forces and contact stresses has attracted a great deal of scientists' attention. In this article, different aspects of transport phenomena in sheared granular media are introduced based on experimental and numerical simulation results obtained by other scientists and via our research. The transport of mass and momentum are basically needed to understand the mixing phenomenon in granular materials. Deformation of granular material (the relative motion of grains) is extremely heterogeneous unlike the ordinary fluids and solids. Also, the most highlighted difference between granular materials and other states of matter is associated with the ineffectiveness of grains thermal energy in building the mechanical and physical properties of granular materials. Instead, the fluctuation of grains kinetic energy plays the major role in controlling the mechanics of granular materials. Strange behaviors of granular materials such as jamming the flow of discharging sand from a hopper and avalanching snow over the surface of mountains can be properly explained only based on the models addressing the transport and the dissipation of grains kinetic energy. (orig.)

  13. Flow-induced vibration analysis of a helical coil steam generator experiment using large eddy simulation

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Haomin; Solberg, Jerome; Merzari, Elia; Kraus, Adam; Grindeanu, Iulian

    2017-10-01

    This paper describes a numerical study of flow-induced vibration in a helical coil steam generator experiment conducted at Argonne National Laboratory in the 1980s. In the experiment, a half-scale sector model of a steam generator helical coil tube bank was subjected to still and flowing air and water, and the vibrational characteristics were recorded. The research detailed in this document utilizes the multi-physics simulation toolkit SHARP developed at Argonne National Laboratory, in cooperation with Lawrence Livermore National Laboratory, to simulate the experiment. SHARP uses the spectral element code Nek5000 for fluid dynamics analysis and the finite element code DIABLO for structural analysis. The flow around the coil tubes is modeled in Nek5000 by using a large eddy simulation turbulence model. Transient pressure data on the tube surfaces is sampled and transferred to DIABLO for the structural simulation. The structural response is simulated in DIABLO via an implicit time-marching algorithm and a combination of continuum elements and structural shells. Tube vibration data (acceleration and frequency) are sampled and compared with the experimental data. Currently, only one-way coupling is used, which means that pressure loads from the fluid simulation are transferred to the structural simulation but the resulting structural displacements are not fed back to the fluid simulation

  14. Monte Carlo simulation of fast neutron scattering experiments including DD-breakup neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, D.; Siebert, B.R.L.

    1993-06-01

    The computational simulation of the deuteron breakup in a scattering experiment has been investigated. Experimental breakup spectra measured at 16 deuteron energies and at 7 angles for each energy served as the data base. Analysis of these input data and of the conditions of the scattering experiment made it possible to reduce the input data. The use of one weighted breakup spectrum is sufficient to simulate the scattering spectra at one incident neutron energy. A number of tests were carried out to prove the validity of this result. The simulation of neutron scattering on carbon, including the breakup, was compared with measured spectra. Differences between calculated and measured spectra were for the most part within the experimental uncertainties. Certain significant deviations can be attributed to erroneous scattering cross sections taken from an evaluation and used in the simulation. Scattering on higher-lying states in [sup 12]C can be analyzed by subtracting the simulated breakup-scattering from the experimental spectra. (orig.)

  15. Monte Carlo simulation of fast neutron scattering experiments including DD-breakup neutrons

    International Nuclear Information System (INIS)

    Schmidt, D.; Siebert, B.R.L.

    1993-06-01

    The computational simulation of the deuteron breakup in a scattering experiment has been investigated. Experimental breakup spectra measured at 16 deuteron energies and at 7 angles for each energy served as the data base. Analysis of these input data and of the conditions of the scattering experiment made it possible to reduce the input data. The use of one weighted breakup spectrum is sufficient to simulate the scattering spectra at one incident neutron energy. A number of tests were carried out to prove the validity of this result. The simulation of neutron scattering on carbon, including the breakup, was compared with measured spectra. Differences between calculated and measured spectra were for the most part within the experimental uncertainties. Certain significant deviations can be attributed to erroneous scattering cross sections taken from an evaluation and used in the simulation. Scattering on higher-lying states in 12 C can be analyzed by subtracting the simulated breakup-scattering from the experimental spectra. (orig.)

  16. Experience of lecturers with simulation training in midwifery education in Slovakia.

    Science.gov (United States)

    Maskálová, Erika; Urbanová, Eva; Bašková, Martina; Kvaltínyová, Eva

    2018-04-01

    The simulation training in midwifery has a long tradition. It is aimed at acquiring basic and advanced practical skills such as performing a certain number of births, episiotomy and subsequent suture, assisting during breech birth etc. Midwifery education is currently based on the requirements of the Directives of the European Union exactly specifying number of performed practical procedures and approaches (World Health Organisation (WHO) Europe, 2009). The aim of this paper is to draw attention to the experience with the simulation training from the teacher's point of view in the study program Midwifery in Slovakia. The authors describe the locations for training of midwifery skills, training of basic and advanced midwifery skills using simulation, the types of simulators available and used and training approaches. They outline the advantages and disadvantages of using obstetric simulators based on their own experience. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Simulation of complete neutron scattering experiments: from model systems to liquid germanium

    International Nuclear Information System (INIS)

    Hugouvieux, V.

    2004-11-01

    In this thesis, both theoretical and experimental studies of liquids are done. Neutron scattering enables structural and dynamical properties of liquids to be investigated. On the theoretical side, molecular dynamics simulations are of great interest since they give positions and velocities of the atoms and the forces acting on each of them. They also enable spatial and temporal correlations to be computed and these quantities are also available from neutron scattering experiments. Consequently, the comparison can be made between results from molecular dynamics simulations and from neutron scattering experiments, in order to improve our understanding of the structure and dynamics of liquids. However, since extracting reliable data from a neutron scattering experiment is difficult, we propose to simulate the experiment as a whole, including both instrument and sample, in order to gain understanding and to evaluate the impact of the different parasitic contributions (absorption, multiple scattering associated with elastic and inelastic scattering, instrument resolution). This approach, in which the sample is described by its structure and dynamics as computed from molecular dynamics simulations, is presented and tested on isotropic model systems. Then liquid germanium is investigated by inelastic neutron scattering and both classical and ab initio molecular dynamics simulations. This enables us to simulate the experiment we performed and to evaluate the influence of the contributions from the instrument and from the sample on the detected signal. (author)

  18. Real Experiments versus Phet Simulations for Better High-School Students' Understanding of Electrostatic Charging

    Science.gov (United States)

    Ajredini, Fadil; Izairi, Neset; Zajkov, Oliver

    2014-01-01

    This research investigates the influence of computer simulations (virtual experiments) on one hand and real experiments on the other hand on the conceptual understanding of electrical charging. The investigated sample consists of students in the second year (10th grade) of three gymnasiums in Macedonia. There were two experimental groups and one…

  19. Comparison between initial Magnetized Liner Inertial Fusion experiments and integrated simulations

    Science.gov (United States)

    Sefkow, A. B.; Gomez, M. R.; Geissel, M.; Hahn, K. D.; Hansen, S. B.; Harding, E. C.; Peterson, K. J.; Slutz, S. A.; Koning, J. M.; Marinak, M. M.

    2014-10-01

    The Magnetized Liner Inertial Fusion (MagLIF) approach to ICF has obtained thermonuclear fusion yields using the Z facility. Integrated magnetohydrodynamic simulations provided the design for the first neutron-producing experiments using capabilities that presently exist, and the initial experiments measured stagnation radii rstag Company, for the National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  20. Serious games experiment toward agent-based simulation

    Science.gov (United States)

    Wein, Anne; Labiosa, William

    2013-01-01

    We evaluate the potential for serious games to be used as a scientifically based decision-support product that supports the United States Geological Survey’s (USGS) mission--to provide integrated, unbiased scientific information that can make a substantial contribution to societal well-being for a wide variety of complex environmental challenges. Serious or pedagogical games are an engaging way to educate decisionmakers and stakeholders about environmental challenges that are usefully informed by natural and social scientific information and knowledge and can be designed to promote interactive learning and exploration in the face of large uncertainties, divergent values, and complex situations. We developed two serious games that use challenging environmental-planning issues to demonstrate and investigate the potential contributions of serious games to inform regional-planning decisions. Delta Skelta is a game emulating long-term integrated environmental planning in the Sacramento-San Joaquin Delta, California, that incorporates natural hazards (flooding and earthquakes) and consequences for California water supplies amidst conflicting water interests. Age of Ecology is a game that simulates interactions between economic and ecologic processes, as well as natural hazards while implementing agent-based modeling. The content of these games spans the USGS science mission areas related to water, ecosystems, natural hazards, land use, and climate change. We describe the games, reflect on design and informational aspects, and comment on their potential usefulness. During the process of developing these games, we identified various design trade-offs involving factual information, strategic thinking, game-winning criteria, elements of fun, number and type of players, time horizon, and uncertainty. We evaluate the two games in terms of accomplishments and limitations. Overall, we demonstrated the potential for these games to usefully represent scientific information

  1. Geant4 simulations of NIST beam neutron lifetime experiment

    Science.gov (United States)

    Valete, Daniel; Crawford, Bret; BL2 Collaboration Collaboration

    2017-09-01

    A free neutron is unstable and its decay is described by the Standard Model as the transformation of a down quark into an up quark through the weak interaction. Precise measurements of the neutron lifetime test the validity of the theory of the weak interaction and provide useful information for the predictions of the theory of Big Bang nucleosynthesis of the primordial helium abundance in the universe and the number of different types of light neutrinos Nν. The predominant experimental methods for determination of the neutron lifetime are commonly called `beam' and `bottle' methods, and the most recent uses of each method do not agree with each other within their stated uncertainties. An improved experiment of the beam technique, which uses magnetic and electric fields to trap and guide the decay protons of a beam of cold neutrons to a detector, is in progress at the National Institute of Standards and Technology, Gaithersburg, MD with a precision goal of 0.1. I acknowledge the support of the Cross-Diciplinary Institute at Gettysburg College.

  2. Simulated Measurements of Cooling in Muon Ionization Cooling Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mohayai, Tanaz [IIT, Chicago; Rogers, Chris [Rutherford; Snopok, Pavel [Fermilab

    2016-06-01

    Cooled muon beams set the basis for the exploration of physics of flavour at a Neutrino Factory and for multi-TeV collisions at a Muon Collider. The international Muon Ionization Cooling Experiment (MICE) measures beam emittance before and after an ionization cooling cell and aims to demonstrate emittance reduction in muon beams. In the current MICE Step IV configuration, the MICE muon beam passes through low-Z absorber material for reducing its transverse emittance through ionization energy loss. Two scintillating fiber tracking detectors, housed in spectrometer solenoid modules upstream and downstream of the absorber are used for reconstructing position and momentum of individual muons for calculating transverse emittance reduction. However, due to existence of non-linear effects in beam optics, transverse emittance growth can be observed. Therefore, it is crucial to develop algorithms that are insensitive to this apparent emittance growth. We describe a different figure of merit for measuring muon cooling which is the direct measurement of the phase space density.

  3. Nanosatellite optical downlink experiment: design, simulation, and prototyping

    Science.gov (United States)

    Clements, Emily; Aniceto, Raichelle; Barnes, Derek; Caplan, David; Clark, James; Portillo, Iñigo del; Haughwout, Christian; Khatsenko, Maxim; Kingsbury, Ryan; Lee, Myron; Morgan, Rachel; Twichell, Jonathan; Riesing, Kathleen; Yoon, Hyosang; Ziegler, Caleb; Cahoy, Kerri

    2016-11-01

    The nanosatellite optical downlink experiment (NODE) implements a free-space optical communications (lasercom) capability on a CubeSat platform that can support low earth orbit (LEO) to ground downlink rates>10 Mbps. A primary goal of NODE is to leverage commercially available technologies to provide a scalable and cost-effective alternative to radio-frequency-based communications. The NODE transmitter uses a 200-mW 1550-nm master-oscillator power-amplifier design using power-efficient M-ary pulse position modulation. To facilitate pointing the 0.12-deg downlink beam, NODE augments spacecraft body pointing with a microelectromechanical fast steering mirror (FSM) and uses an 850-nm uplink beacon to an onboard CCD camera. The 30-cm aperture ground telescope uses an infrared camera and FSM for tracking to an avalanche photodiode detector-based receiver. Here, we describe our approach to transition prototype transmitter and receiver designs to a full end-to-end CubeSat-scale system. This includes link budget refinement, drive electronics miniaturization, packaging reduction, improvements to pointing and attitude estimation, implementation of modulation, coding, and interleaving, and ground station receiver design. We capture trades and technology development needs and outline plans for integrated system ground testing.

  4. Impact of audio-visual storytelling in simulation learning experiences of undergraduate nursing students.

    Science.gov (United States)

    Johnston, Sandra; Parker, Christina N; Fox, Amanda

    2017-09-01

    Use of high fidelity simulation has become increasingly popular in nursing education to the extent that it is now an integral component of most nursing programs. Anecdotal evidence suggests that students have difficulty engaging with simulation manikins due to their unrealistic appearance. Introduction of the manikin as a 'real patient' with the use of an audio-visual narrative may engage students in the simulated learning experience and impact on their learning. A paucity of literature currently exists on the use of audio-visual narratives to enhance simulated learning experiences. This study aimed to determine if viewing an audio-visual narrative during a simulation pre-brief altered undergraduate nursing student perceptions of the learning experience. A quasi-experimental post-test design was utilised. A convenience sample of final year baccalaureate nursing students at a large metropolitan university. Participants completed a modified version of the Student Satisfaction with Simulation Experiences survey. This 12-item questionnaire contained questions relating to the ability to transfer skills learned in simulation to the real clinical world, the realism of the simulation and the overall value of the learning experience. Descriptive statistics were used to summarise demographic information. Two tailed, independent group t-tests were used to determine statistical differences within the categories. Findings indicated that students reported high levels of value, realism and transferability in relation to the viewing of an audio-visual narrative. Statistically significant results (t=2.38, psimulation to clinical practice. The subgroups of age and gender although not significant indicated some interesting results. High satisfaction with simulation was indicated by all students in relation to value and realism. There was a significant finding in relation to transferability on knowledge and this is vital to quality educational outcomes. Copyright © 2017. Published by

  5. Stress induced conditioning and thermal relaxation in the simulation of quasi-static compression experiments

    CERN Document Server

    Scalerandi, M; Johnson, P A

    2003-01-01

    Local interaction simulation approach simulations of the ultrasonic wave propagation in multi-grained materials have succeeded in reproducing most of the recently observed nonclassical nonlinear effects, such as stress-strain hysteresis and discrete memory in quasi-static experiments and a downwards shift of the resonance frequency and the generation of odd harmonics at specific amplitude rates in dynamics experiments. By including a simple mechanism of thermally activated random transitions, we can predict the occurrence of experimentally observed effects, such as the conditioning and relaxation of the specimen. Experiments are also suggested for a quantitative assessment of the validity of the model.

  6. Stress induced conditioning and thermal relaxation in the simulation of quasi-static compression experiments

    International Nuclear Information System (INIS)

    Scalerandi, M; Delsanto, P P; Johnson, P A

    2003-01-01

    Local interaction simulation approach simulations of the ultrasonic wave propagation in multi-grained materials have succeeded in reproducing most of the recently observed nonclassical nonlinear effects, such as stress-strain hysteresis and discrete memory in quasi-static experiments and a downwards shift of the resonance frequency and the generation of odd harmonics at specific amplitude rates in dynamics experiments. By including a simple mechanism of thermally activated random transitions, we can predict the occurrence of experimentally observed effects, such as the conditioning and relaxation of the specimen. Experiments are also suggested for a quantitative assessment of the validity of the model

  7. Simulation of the Quench-06 experiment with Scdapsim; Simulacion del experimento Quench-06 con Scdapsim

    Energy Technology Data Exchange (ETDEWEB)

    Angel M, E. del; Nunez C, A.; Amador G, R. [CNSNS, Dr. Barragan No. 779, 03020 Mexico D.F. (Mexico)]. e-mail: edangelm@cnsns.gob.mx

    2003-07-01

    The present work describes the pattern of the called Quench installation developed and used by the National Commission of Nuclear Security and Safeguards (CNSNS) for their participation in the International Standard Problem 45 (ISP), organized by the Nuclear Energy Agency (NEA). The exercise consisted on the simulation of the denominated experiment Quench-06 carried out in the experimental installation Quench located in the Forschungszentrum laboratory in Karlsruhe, Germany. The experiment Quench-06 consisted on simulating the sudden and late injection of water in a fuel assemble for a pressurized reactor (PWR). The CNSNS uses the version bd of the SCDAPSIM code developed by the company Innovative Software Systems (ISS) to simulate this experiment. The obtained results showed that the code is able to predict the experiment partially when overestimating the hydrogen production and of the partial fused of some fuel pellets, but predicting correctly the damage in the shroud. (Author)

  8. Simulation of MASPn experiments in MISTRA test facility with COCOSYS code

    International Nuclear Information System (INIS)

    Povilaitis, M.; Urbonavicius, E.

    2007-01-01

    Paper describes simulation of MASPn experiments, which were performed in the MISTRA test facility, with lumped-parameter code COCOSYS. MASPn experiments belong to the SARNET spray benchmark, which was initiated in the Containment Atmosphere Mixing work package. The objective of this benchmark is to evaluate the spray modelling in the containment codes. The paper presents developed MISTRA nodalisation scheme for COCOSYS code, and the results of performed analysis. It is shown that a clear specification of experiments initial conditions is needed to perform the simulation of the experiments. The performed parametric analysis shows that in the simulation the heat losses through the external walls behind the lower condenser installed in the MISTRA facility determines the long-term depressurisation rate. (author)

  9. Mechanical Properties of Boehmite Evaluated by Atomic Force Microscopy Experiments and Molecular Dynamic Finite Element Simulations

    International Nuclear Information System (INIS)

    Fankhanel, J.; Daum, B.; Kempe, A.; Rolfes, R.; Silbernagl, D.; Khorasani, M.Gh.Z.; Sturm, H.; Sturm, H.

    2016-01-01

    Boehmite nanoparticles show great potential in improving mechanical properties of fiber reinforced polymers. In order to predict the properties of nanocomposites, knowledge about the material parameters of the constituent phases, including the boehmite particles, is crucial. In this study, the mechanical behavior of boehmite is investigated using Atomic Force Microscopy (AFM) experiments and Molecular Dynamic Finite Element Method (MDFEM) simulations. Young’s modulus of the perfect crystalline boehmite nanoparticles is derived from numerical AFM simulations. Results of AFM experiments on boehmite nanoparticles deviate significantly. Possible causes are identified by experiments on complementary types of boehmite, that is, geological and hydrothermally synthesized samples, and further simulations of imperfect crystals and combined boehmite/epoxy models. Under certain circumstances, the mechanical behavior of boehmite was found to be dominated by inelastic effects that are discussed in detail in the present work. The studies are substantiated with accompanying X-ray diffraction and Raman experiments.

  10. Simulations of the Ion-Hose Instability for DARHT-II Long-Pulse Experiments

    CERN Document Server

    Chan, K C D

    2004-01-01

    Ion-hose effect has been described extensively in literatures. Computer simulations of the effect typically use particle-in-cell (PIC) computer codes or codes using the spread-mass formulation [1]. PIC simulations, though offering more reliable results, will require extended running time in large computers To support commissioning experiments in the DARHT-II induction linac in Los Alamos National Laboratory, we have modified a spread-mass code so that we can survey quickly the parameter space for the experiment. It can also be used to provide quick answers during experiment. The code was originally written by Genoni from Mission Research Corporation (MRC) for constant linac parameters. We have modified it so that parameters can have dependence along the length of the linac. In this paper, we will describe simulation results using this code for the DARHT-II commissioning experiment and also our benchmarking results comparing to LSP, a PIC code from MRC.

  11. NUCLEBRAS' experience in the implantation of a nuclear power plants simulator

    International Nuclear Information System (INIS)

    Spitalnik, J.; Fonseca, G.

    1985-01-01

    The experiences gained by NUCLEBRAS in the setting up of a Nuclear Power Plant Simulator Training Center, cover the design and manufacture of the simulator for the Angra-2 type nuclear power plants, the training of the simulator operation and maintenance personnel, in preparation for the training of the Brazilian nuclear power plant operators, the development of the simulator training programs and materials, the temporary installation and utilization of the simulator in the FRG, including the training of operators of the Trillo nuclear power plant, in Spain. The simulator shall be finally installed in Brazil, at the vicinity of the Angra-2 site, in 1985, when it is foreseen to start the training of the Angra-2 operators. (Author) [pt

  12. Analysis of Cavity Pressure and Warpage of Polyoxymethylene Thin Walled Injection Molded Parts: Experiments and Simulations

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Tosello, Guido; Hattel, Jesper Henri

    2014-01-01

    Process analysis and simulations on molding experiments of 3D thin shell parts have been conducted. Moldings were carried out with polyoxymethylene (POM). The moldings were performed with cavity pressure sensors in order to compare experimental process results with simulations. The warpage...... was characterized by measuring distances using a tactile coordinate measuring machine (CMM). Molding simulations have been executed taking into account actual processing conditions. Various aspects have been considered in the simulation: machine barrel geometry, injection speed profiles, cavity injection pressure...... of conclusions concerning improvements to simulation accuracy are presented regarding: pvT data, mesh, short shots, cavity pressure for process control validation as well as molding machine geometry modelling. Eventually, a methodology for improved molding simulations of cavity injection pressure, filling...

  13. Simulated and Virtual Science Laboratory Experiments: Improving Critical Thinking and Higher-Order Learning Skills

    Science.gov (United States)

    Simon, Nicole A.

    Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory experience, linking with educational technologies (Pyatt & Sims, 2007; 2011; Trundle & Bell, 2010). A causal-comparative quantitative study was conducted with 150 learners enrolled at a two-year community college, to determine the effects of simulation laboratory experiments on Higher-Order Learning, Critical Thinking Skills, and Cognitive Load. The treatment population used simulated experiments, while the non-treatment sections performed traditional expository experiments. A comparison was made using the Revised Two-Factor Study Process survey, Motivated Strategies for Learning Questionnaire, and the Scientific Attitude Inventory survey, using a Repeated Measures ANOVA test for treatment or non-treatment. A main effect of simulated laboratory experiments was found for both Higher-Order Learning, [F (1, 148) = 30.32,p = 0.00, eta2 = 0.12] and Critical Thinking Skills, [F (1, 148) = 14.64,p = 0.00, eta 2 = 0.17] such that simulations showed greater increases than traditional experiments. Post-lab treatment group self-reports indicated increased marginal means (+4.86) in Higher-Order Learning and Critical Thinking Skills, compared to the non-treatment group (+4.71). Simulations also improved the scientific skills and mastery of basic scientific subject matter. It is recommended that additional research recognize that learners' Critical Thinking Skills change due to different instructional methodologies that occur throughout a semester.

  14. Voxel-based Monte Carlo simulation of X-ray imaging and spectroscopy experiments

    International Nuclear Information System (INIS)

    Bottigli, U.; Brunetti, A.; Golosio, B.; Oliva, P.; Stumbo, S.; Vincze, L.; Randaccio, P.; Bleuet, P.; Simionovici, A.; Somogyi, A.

    2004-01-01

    A Monte Carlo code for the simulation of X-ray imaging and spectroscopy experiments in heterogeneous samples is presented. The energy spectrum, polarization and profile of the incident beam can be defined so that X-ray tube systems as well as synchrotron sources can be simulated. The sample is modeled as a 3D regular grid. The chemical composition and density is given at each point of the grid. Photoelectric absorption, fluorescent emission, elastic and inelastic scattering are included in the simulation. The core of the simulation is a fast routine for the calculation of the path lengths of the photon trajectory intersections with the grid voxels. The voxel representation is particularly useful for samples that cannot be well described by a small set of polyhedra. This is the case of most naturally occurring samples. In such cases, voxel-based simulations are much less expensive in terms of computational cost than simulations on a polygonal representation. The efficient scheme used for calculating the path lengths in the voxels and the use of variance reduction techniques make the code suitable for the detailed simulation of complex experiments on generic samples in a relatively short time. Examples of applications to X-ray imaging and spectroscopy experiments are discussed

  15. Reform and practice for photoelectric specialty experimental teaching based on virtual simulation experiment platform

    Science.gov (United States)

    Ye, Yan; Lv, Qingsong; Wu, Maocheng; Xu, Yishen; Gu, Jihua

    2017-08-01

    In view of some problems about the traditional photoelectric specialty experimental teaching process, such as separation of theoretical teaching and practical teaching, immobilization of experimental teaching contents, low quality of experiments and no obvious effect, we explored and practiced a new experimental teaching model of "theoretical teaching, virtual simulation and physical experiment", which combined the characteristics of photoelectric information science and engineering major and the essential requirements of engineering innovation talents cultivation. The virtual simulation experiment platform has many advantages, such as high performance-to-price ratio, easy operation and open experimental process, which makes virtual simulation combine physical experiment, complete each other with virtual for practical. After the users log into the virtual simulation experimental platform, they will first study the contents of the experiment, clarify the purpose and requirements of the experiment, master the method of using the instrument and the relevant notes, and then use the experimental instruments provided by the platform to build the corresponding experimental system. Once the experimenter's optical path is set incorrectly or the instrument parameters are set incorrectly, the error or warning message will be automatically triggered, and the reference information will be given instructing the student to complete the correct experimental operation. The results of our practice in recent years show that the teaching reform of the photoelectric specialty experiments has not only brought great convenience to the experimental teaching management, broadened the students' thinking and vision, enhanced the students' experimental skills and comprehensive qualities, but also made the students participate in the experiment with their enthusiasm. During the construction of experiment programs, the students' engineering practical ability and independent innovation awareness

  16. Study of Multi-phase Flow in Porous Media : Comparison of SPH Simulations with Micro-model Experiments

    OpenAIRE

    Kunz, P.; Zarikos, I. M.; Karadimitriou, N. K.; Huber, M.; Nieken, U.; Hassanizadeh, S. M.

    2016-01-01

    We present simulations and experiments of drainage processes in a micro-model. A direct numerical simulation is introduced which is capable of describing wetting phenomena on the pore scale. A numerical smoothed particle hydrodynamics model was developed and used to simulate the two-phase flow of immiscible fluids. The experiments were performed in a micro-model which allows the visualization of interface propagation in detail. We compare the experiments and simulations of a quasistatic drain...

  17. Simulation of IRIS 2010 missile experiments for validation of integral simulation approach

    International Nuclear Information System (INIS)

    Siefert, Alexander; Henkel, Fritz-Otto

    2013-01-01

    Conclusion: Used material model and model approach shows acceptable results in comparison with test data, but further improvements are possible. Tri-axial Test: The material model must be improved to capture the higher strain values for test with confining pressure. Possible solution: Defining separate damage curves for different confining pressures. Flexural Test: Model approach has to be approved regarding the swing back phase. Possible first step: Investigation of crack closing –tensional recovery. Punching Test: Challenge for this simulation is the element erosions. Solution: Defining a reliable deletion criteria is possible by averaging several case studies. Alternative is the application of SPH-method. In General: Material properties showed differences to code definitions. Therefore a required input for detailed analysis of local damage are test data (especially for existing structures). Microscopic cracking can’t be investigated using a homogenous material

  18. Isotachophoresis of proteins in a networked microfluidic chip: experiment and 2-D simulation.

    Science.gov (United States)

    Cui, Huanchun; Dutta, Prashanta; Ivory, Cornelius F

    2007-04-01

    This paper reports both the experimental application and 2-D simulation of ITP of proteins in a networked microfluidic chip. Experiments demonstrate that a mixture of three fluorescent proteins can be concentrated and stacked into adjacent zones of pure protein under a constant voltage of 100 V over a 2 cm long microchannel. Measurements of the isotachophoretic velocity of the moving zones demonstrates that, during ITP under a constant voltage, the zone velocity decreases as more of the channel is occupied by the terminating electrolyte. A 2-D ITP model based on the Nernst-Planck equations illustrates the stacking and separation features of ITP using simulations of three virtual proteins. The self-sharpening behavior of ITP zones dispersed by a T-junction is clearly demonstrated both by experiment and by simulation. Comparison of 2-D simulations of ITP and zone electrophoresis (ZE) confirms that ZE lacks the ability to resharpen protein zones after they pass through a T-junction.

  19. Nucleic acid polymeric properties and electrostatics: Directly comparing theory and simulation with experiment.

    Science.gov (United States)

    Sim, Adelene Y L

    2016-06-01

    Nucleic acids are biopolymers that carry genetic information and are also involved in various gene regulation functions such as gene silencing and protein translation. Because of their negatively charged backbones, nucleic acids are polyelectrolytes. To adequately understand nucleic acid folding and function, we need to properly describe its i) polymer/polyelectrolyte properties and ii) associating ion atmosphere. While various theories and simulation models have been developed to describe nucleic acids and the ions around them, many of these theories/simulations have not been well evaluated due to complexities in comparison with experiment. In this review, I discuss some recent experiments that have been strategically designed for straightforward comparison with theories and simulation models. Such data serve as excellent benchmarks to identify limitations in prevailing theories and simulation parameters. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Validation of a numerical FSI simulation of an aortic BMHV by in vitro PIV experiments.

    Science.gov (United States)

    Annerel, S; Claessens, T; Degroote, J; Segers, P; Vierendeels, J

    2014-08-01

    In this paper, a validation of a recently developed fluid-structure interaction (FSI) coupling algorithm to simulate numerically the dynamics of an aortic bileaflet mechanical heart valve (BMHV) is performed. This validation is done by comparing the numerical simulation results with in vitro experiments. For the in vitro experiments, the leaflet kinematics and flow fields are obtained via the particle image velocimetry (PIV) technique. Subsequently, the same case is numerically simulated by the coupling algorithm and the resulting leaflet kinematics and flow fields are obtained. Finally, the results are compared, revealing great similarity in leaflet motion and flow fields between the numerical simulation and the experimental test. Therefore, it is concluded that the developed algorithm is able to capture very accurately all the major leaflet kinematics and dynamics and can be used to study and optimize the design of BMHVs. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  1. Simulation, realization and test of veto systems for the NA62 experiment

    OpenAIRE

    Palladino, Vito; Ambrosino, Fabio

    2015-01-01

    Search Simple Search Advanced Search Latest Additions Browse Browse by Author Browse by Subject Browse by Year Browse by Type Browse by Full text availability Info Policy About FAQ Contact us Palladino, Vito (2010) Simulation, realization and test of veto systems for the NA62 experiment. [Tesi di dottorato] (Unpublished) [img] PDF palladino_vito_23.pdf Download (55MB) | Preview Item Type: Tesi di dottorato Language: English Title: Simulation, realization and test of veto systems for the...

  2. Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

    International Nuclear Information System (INIS)

    Gerlach, M.; Krumrey, M.; Cibik, L.; Mueller, P.; Ulm, G.

    2009-01-01

    Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

  3. Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

    Science.gov (United States)

    Gerlach, M.; Krumrey, M.; Cibik, L.; Müller, P.; Ulm, G.

    2009-09-01

    Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

  4. Comparison of scattering experiments using synchrotron radiation with Monte Carlo simulations using Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, M. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany); Krumrey, M. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)], E-mail: Michael.Krumrey@ptb.de; Cibik, L.; Mueller, P.; Ulm, G. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

    2009-09-11

    Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering experiments using monochromatized synchrotron radiation in the X-ray regime are quantitatively compared to the results of simulations using Geant4. Experiments were performed for various scattering foils made of different materials such as copper and gold. For energy-dispersive measurements of the scattered radiation, a cadmium telluride detector was used. The detector was fully characterized and calibrated with calculable undispersed as well as monochromatized synchrotron radiation. The obtained quantum efficiency and the response functions are in very good agreement with the corresponding Geant4 simulations. At the electron storage ring BESSY II the number of incident photons in the scattering experiments was measured with a photodiode that had been calibrated against a cryogenic radiometer, so that a direct comparison of scattering experiments with Monte Carlo simulations using Geant4 was possible. It was shown that Geant4 describes the photoeffect, including fluorescence as well as the Compton and Rayleigh scattering, with high accuracy, resulting in a deviation of typically less than 20%. Even polarization effects are widely covered by Geant4, and for Doppler broadening of Compton-scattered radiation the extension G4LECS can be included, but the fact that both features cannot be combined is a limitation. For most polarization-dependent simulations, good agreement with the experimental results was found, except for some orientations where Rayleigh scattering was overestimated in the simulation.

  5. Simultaneous ion and neutral evaporation in aqueous nanodrops: Experiment, theory, and molecular dynamics simulations

    OpenAIRE

    Higashi, Hidenori; Tokumi, Takuya; Hogan, Christopher J. Jr.; Suda, Horoshi; Seto, Takafumi; Otani, Yoshio

    2015-01-01

    We use a combination of tandem ion mobility spectrometry (IMS-IMS, with differential mobility analyzers), molecular dynamics (MD) simulations, and analytical models to examine both neutral solvent (H2O) and ion (solvated Na+) evaporation from aqueous sodium chloride nanodrops. For experiments, nanodrops were produced via electrospray ionization (ESI) of an aqueous sodium chloride solution. Two nanodrops were examined in MD simulations: a 2500 water molecule nanodrop with 68 Na+ and 60 Cl- ion...

  6. [An interprofessional simulation: an exploration of the experiences of nursing students.

    Science.gov (United States)

    Lalonde, Michelle; Malouin-Benoit, Marie-Christine; Gagnon, Elizabeth; Michon, Alain; Maisonneuve, Monique; Desroches, Janie

    2017-12-01

    the literature suggests that simulation is an effective strategy to meet the learning needs of nursing students. Traditionally, simulation learning for nursing students takes place at nursing schools ; at a distance from the clinical setting, patients, and the interprofessional team. the objective of this pilot project is to explore the experiences of Francophone nursing students following their participation in an interprofessional simulation in a hospital setting during their third year clinical placements. a case study using Yin's (2003) approach was used to explore this phenomenon through focus groups and individual interviews. thirteen people participated in three simulation sessions that each included two scenarios. Content analysis of the focus groups revealed four themes : 1) the need for a realistic, but safe environment ; 2) simulation helps to build self-confidence ; 3) simulation improves knowledge of the role of the nurse ; and 4) simulation improves knowledge of teamwork. Two themes emerged from individual interviews : 1) the knowledge and skills acquired during the simulation were retained over time ; and 2) perceptions of the effects on the quality and safety of patient care. the use of simulation could be effective for the development of knowledge of nursing role, teamwork, and self-confidence.

  7. Computer Simulation and Field Experiment for Downlink Multiuser MIMO in Mobile WiMAX System.

    Science.gov (United States)

    Yamaguchi, Kazuhiro; Nagahashi, Takaharu; Akiyama, Takuya; Matsue, Hideaki; Uekado, Kunio; Namera, Takakazu; Fukui, Hiroshi; Nanamatsu, Satoshi

    2015-01-01

    The transmission performance for a downlink mobile WiMAX system with multiuser multiple-input multiple-output (MU-MIMO) systems in a computer simulation and field experiment is described. In computer simulation, a MU-MIMO transmission system can be realized by using the block diagonalization (BD) algorithm, and each user can receive signals without any signal interference from other users. The bit error rate (BER) performance and channel capacity in accordance with modulation schemes and the number of streams were simulated in a spatially correlated multipath fading environment. Furthermore, we propose a method for evaluating the transmission performance for this downlink mobile WiMAX system in this environment by using the computer simulation. In the field experiment, the received power and downlink throughput in the UDP layer were measured on an experimental mobile WiMAX system developed in Azumino City in Japan. In comparison with the simulated and experimented results, the measured maximum throughput performance in the downlink had almost the same performance as the simulated throughput. It was confirmed that the experimental mobile WiMAX system for MU-MIMO transmission successfully increased the total channel capacity of the system.

  8. Numerical Simulation and Experiment for Underwater Shock Wave in Newly Designed Pressure Vessel

    Directory of Open Access Journals (Sweden)

    M Shibuta

    2016-09-01

    Full Text Available Modern eating habits depend in large part on the development of food processing technology. Thermal treatments are often performed in the conventional food processing, but it can cause discoloration and loss of nutrients of the food by thermal processing or treatment. On the other hand, food processing using an underwater shock wave has little influence of heat and its processing time is very short, preventing the loss of nutrients. In this research optical observation experiment and the numerical simulation were performed, in order to understand and control the behavior of the underwater shock wave in the development of the processing container using an underwater shock wave for the factory and home. In this experiment a rectangular container was used to observe the behavior of the underwater shock wave. In the experiment, the shock wave was generated by using explosive on the shock wave generation side. The shock wave, which passed through the phosphor bronze and propagated from the aluminum sidewall, was observed on the processing container side. Numerical simulation of an analogous experimental model was investigated, where LS-DYNA software was used for the numerical simulation. The comparative study of the experiment and the numerical simulation was investigated. The behavior of a precursor shock wave from the device wall was able to be clarified. This result is used for development of the device in numerical simulation.

  9. Implementation of Hydrodynamic Simulation Code in Shock Experiment Design for Alkali Metals

    Science.gov (United States)

    Coleman, A. L.; Briggs, R.; Gorman, M. G.; Ali, S.; Lazicki, A.; Swift, D. C.; Stubley, P. G.; McBride, E. E.; Collins, G.; Wark, J. S.; McMahon, M. I.

    2017-10-01

    Shock compression techniques enable the investigation of extreme P-T states. In order to probe off-Hugoniot regions of P-T space, target makeup and laser pulse parameters must be carefully designed. HYADES is a hydrodynamic simulation code which has been successfully utilised to simulate shock compression events and refine the experimental parameters required in order to explore new P-T states in alkali metals. Here we describe simulations and experiments on potassium, along with the techniques required to access off-Hugoniot states.

  10. Nonlinear soil-structure interaction calculations simulating the SIMQUAKE experiment using STEALTH 2D

    Science.gov (United States)

    Tang, H. T.; Hofmann, R.; Yee, G.; Vaughan, D. K.

    1980-01-01

    Transient, nonlinear soil-structure interaction simulations of an Electric Power Research Institute, SIMQUAKE experiment were performed using the large strain, time domain STEALTH 2D code and a cyclic, kinematically hardening cap soil model. Results from the STEALTH simulations were compared to identical simulations performed with the TRANAL code and indicate relatively good agreement between all the STEALTH and TRANAL calculations. The differences that are seen can probably be attributed to: (1) large (STEALTH) vs. small (TRANAL) strain formulation and/or (2) grid discretization differences.

  11. Using Critical Care Simulations to Prepare Nursing Students for Capstone Clinical Experiences.

    Science.gov (United States)

    Smallheer, Benjamin; Hunt, Jennifer; Smith, Judson

    The purpose of this innovative learning strategy was to decrease students' fear and anxiety within the critical care environment before the initiation of a critical care capstone clinical experience by enhancing their familiarity of the critical care environment through deliberate practice and experiential learning. This will in turn increase student knowledge and competence in the critical care setting.Critical care units are often used during a capstone clinical experience to enhance critical thinking and clinical reasoning. Student preparation for these rotations, however, is varied and often inadequate. The resulting fear and anxiety impair learning and also contribute to an unsafe environment for this at-risk population.Before the capstone experience, students participated in 3 simulation experiences, each addressing a core concept of critical care nursing. Faculty engaged students during the simulations, while modeling the confidence and critical thinking of a critical care nurse.After both the critical care simulation and the capstone rotation, students stated that the simulation allowed them the time in a safe environment to critically think through the steps to care for critical patients before the capstone rotation. The experience provided them with increased confidence necessary to discharge the responsibilities of a critical care nurse-attention to critical thinking and reasoning.Mindfully constructed simulations with clear objectives help to inoculate the student against fears associated with high-risk patients. This decrease in fear and anxiety before a hands-on clinical experience may improve patient safety. More confident students are also better able to engage in both experiential and deliberate learning, resulting in a more enhanced and meaningful clinical experience.

  12. Simulation of pendulum shock experiments on a passenger car front axle; Simulation von Pendelschlagversuchen an einer PKW-Vorderachse

    Energy Technology Data Exchange (ETDEWEB)

    Sporer, L.; Witt, R.; Muehlbauer, R. [BMW Group, Muenchen (Germany)

    2001-07-01

    The contribution describes the development and application of a method for simulating loads resulting from misuse on car body components. The development of the method and its validation by experiments are described, and its application in the development of the BMW-5 series is gone into. [German] Der Beitrag beschreibt die Entwicklung und Anwendung einer Methode zur Simulation von Missbrauchsbelastungen an Fahrwerkskomponenten. Im ersten Abschnitt ist die systematische Entstehung der Methode und die Absicherung der Simulationsergebnisse durch Ersatzversuche dargestellt. In den folgenden Abschnitten steht die Anwendung der Methode in der Fahrwerksentwicklung bei BMW am Beispiel der Vorderachse der aktuellen 5-er Baureihe im Vordergrund. Das Deformationsverhalten einzelner Lenker bzw. die Schadenskette an der gesamten Achse werden sowohl fuer den seitlichen, als auch fuer den frontalen Pendelschlag aufgezeigt. (orig.)

  13. Event-by-event simulation of nonclassical effects in two-photon interference experiments

    OpenAIRE

    Michielsen, Kristel; Jin, Fengping; Delina, Mutia; De Raedt, Hans

    2012-01-01

    A corpuscular simulation model for second-order intensity interference phenomena is discussed. It is shown that both the visibility ${\\cal V}=1/2$ predicted for two-photon interference experiments with two independent sources and the visibility ${\\cal V}=1$ predicted for two-photon interference experiments with a parametric down-conversion source can be explained in terms of a locally causal, modular, adaptive, corpuscular, classical (non-Hamiltonian) dynamical system. Hence, there is no need...

  14. Laboratory simulation of the formation of an ionospheric depletion using Keda Space Plasma EXperiment (KSPEX)

    OpenAIRE

    Pengcheng Yu; Yu Liu; Jinxiang Cao; Jiuhou Lei; Zhongkai Zhang; Xiao Zhang

    2017-01-01

    In the work, the formation of an ionospheric depletion was simulated in a controlled laboratory plasma. The experiment was performed by releasing chemical substance sulfur hexafluoride (SF6) into the pure argon discharge plasma. Results indicate that the plasma parameters change significantly after release of chemicals. The electron density is nearly depleted due to the sulfur hexafluoride-electron attachment reaction; and the electron temperature and space potential experience an increase du...

  15. Corpuscular event-by-event simulation of quantum optics experiments: application to a quantum-controlled delayed-choice experiment

    International Nuclear Information System (INIS)

    De Raedt, Hans; Delina, M; Jin, Fengping; Michielsen, Kristel

    2012-01-01

    A corpuscular simulation model of optical phenomena that does not require 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 is discussed. The event-based corpuscular model gives a unified description of multiple-beam fringes of a plane parallel plate and a single-photon Mach-Zehnder interferometer, Wheeler's delayed choice, photon tunneling, quantum eraser, two-beam interference, Einstein-Podolsky-Rosen-Bohm and Hanbury Brown-Twiss experiments. The approach is illustrated by applying it to a recent proposal for a quantum-controlled delayed choice experiment, demonstrating that also this thought experiment can be understood in terms of particle processes only.

  16. High-fidelity simulation in Neonatology and the Italian experience of Nina

    Directory of Open Access Journals (Sweden)

    Armando Cuttano

    2012-10-01

    Full Text Available The modern methodology of simulation was born in the aeronautical field. In medicine, anesthetists showed great attention for technological advances and simulation, closely followed by surgeons with minimally invasive surgery. In Neonatology training in simulation is actually useful in order to face unexpected dramatic events, to minimize clinical risk preventing errors and to optimize team work. Critical issues in simulation are: teachers-learners relationship, focus on technical and non-technical skills, training coordination, adequate scenarios, effective debriefing. Therefore, the quality of a simulation training center is multi-factorial and is not only related to the mannequin equipment. High-fidelity simulation is the most effective method in education. In Italy simulation for education in Medicine has been used for a few years only. In Pisa we founded Nina (that is the acronymous for the Italian name of the Center, CeNtro di FormazIone e SimulazioNe NeonAtale, the first neonatal simulation center dedicated but integrated within a Hospital Unit in Italy. This paper describes how we manage education in Nina Center, in order to offer a model for other similar experiences.

  17. Simulation and modeling of the Gamble II self-pinched ion beam transport experiment

    International Nuclear Information System (INIS)

    Rose, D.V.; Ottinger, P.F.; Hinshelwood, D.D.

    1999-01-01

    Progress in numerical simulations and modeling of the self-pinched ion beam transport experiment at the Naval Research Laboratory (NRL) is reviewed. In the experiment, a 1.2-MeV, 100-kA proton beam enters a 1-m long, transport region filled with a low pressure gas (30--250 mTorr helium, or 1 Torr air). The time-dependent velocity distribution function of the injected ion beam is determined from an orbit code that uses a pinch-reflex ion diode model and the measured voltage and current from this diode on the Gamble II generator at NRL. This distribution function is used as the beam input condition for numerical simulations carried out using the hybrid particle-in-cell code IPROP. Results of the simulations will be described, and detailed comparisons will be made with various measurements, including line-integrated electron-density, proton-fluence, and beam radial-profile measurements. As observed in the experiment, the simulations show evidence of self-pinching for helium pressures between 35 and 80 mTorr. Simulations and measurements in 1 Torr air show ballistic transport. The relevance of these results to ion-driven inertial confinement fusion will be discussed

  18. Computer-intensive simulation of solid-state NMR experiments using SIMPSON.

    Science.gov (United States)

    Tošner, Zdeněk; Andersen, Rasmus; Stevensson, Baltzar; Edén, Mattias; Nielsen, Niels Chr; Vosegaard, Thomas

    2014-09-01

    Conducting large-scale solid-state NMR simulations requires fast computer software potentially in combination with efficient computational resources to complete within a reasonable time frame. Such simulations may involve large spin systems, multiple-parameter fitting of experimental spectra, or multiple-pulse experiment design using parameter scan, non-linear optimization, or optimal control procedures. To efficiently accommodate such simulations, we here present an improved version of the widely distributed open-source SIMPSON NMR simulation software package adapted to contemporary high performance hardware setups. The software is optimized for fast performance on standard stand-alone computers, multi-core processors, and large clusters of identical nodes. We describe the novel features for fast computation including internal matrix manipulations, propagator setups and acquisition strategies. For efficient calculation of powder averages, we implemented interpolation method of Alderman, Solum, and Grant, as well as recently introduced fast Wigner transform interpolation technique. The potential of the optimal control toolbox is greatly enhanced by higher precision gradients in combination with the efficient optimization algorithm known as limited memory Broyden-Fletcher-Goldfarb-Shanno. In addition, advanced parallelization can be used in all types of calculations, providing significant time reductions. SIMPSON is thus reflecting current knowledge in the field of numerical simulations of solid-state NMR experiments. The efficiency and novel features are demonstrated on the representative simulations. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. The development and psychometric testing of the Satisfaction with Simulation Experience Scale.

    Science.gov (United States)

    Levett-Jones, Tracy; McCoy, Michelle; Lapkin, Samuel; Noble, Danielle; Hoffman, Kerry; Dempsey, Jennifer; Arthur, Carol; Roche, Jan

    2011-10-01

    This paper reports the development and psychometric testing of the Satisfaction with Simulation Experience Scale, an instrument designed to measure and compare differences in satisfaction levels between nursing students exposed to medium and high fidelity human patient simulation manikins. Student satisfaction is important to engaged and meaningful learning and it facilitates active and purposeful participation in simulation experiences. There are suggestions that student satisfaction may have some correlation with performance. Few studies have explored in a rigorous way the impact of manikin fidelity on nursing students' satisfaction with simulation experiences. The items for the Satisfaction with Simulation Experience Scale were identified following a critical review of the literature. Content validly was established by use of an expert panel. During 2009 and 2010 the instrument was tested with second year (n=268) and third year nursing students (n=76) from one Australian university. Exploratory factor analysis with varimax rotation was used to determine construct validity and Cronbach's coefficient alpha determined the scale's internal consistency reliability. Differences in satisfaction levels between groups were analysed using an independent t test. Responses to an open ended question were categorised using thematic content analysis. The scale demonstrated satisfactory internal consistency (alpha 0.77). Exploratory factor analysis yielded a three-component structure termed Debriefing and Reflection, Clinical Reasoning, and Clinical Learning; each subscale demonstrated high internal consistency: 0.94; 0.86; 0.85 respectively. Mean satisfaction scores were high for each group. However, statistically significant differences were not apparent between second or third year students exposed to medium and high fidelity manikins. Content analysis identified 13 main categories including supplementing versus replacing clinical placements and the need for increased

  20. Emergence of a Barchan Belt in a Unidirectional Flow: Experiment and Numerical Simulation

    OpenAIRE

    Katsuki, Atsunari; Kikuchi, Macoto; Endo, Noritaka

    2004-01-01

    We observed time evolution of dune fields in a water tank experiment and simulated it by using a simple model without taking complex fluid dynamics into account. The initial sand bed changed its form into transverse ripples, that is, dunes with straight crest lines perpendicular to the flow direction. Then the crescentic shaped dunes called barchans emerged from transverse ripples.

  1. Cyclic Voltammetry Simulations with DigiSim Software: An Upper-Level Undergraduate Experiment

    Science.gov (United States)

    Messersmith, Stephania J.

    2014-01-01

    An upper-division undergraduate chemistry experiment is described which utilizes DigiSim software to simulate cyclic voltammetry (CV). Four mechanisms were studied: a reversible electron transfer with no subsequent or proceeding chemical reactions, a reversible electron transfer followed by a reversible chemical reaction, a reversible chemical…

  2. Simultaneous Epicardial and Noncontact Endocardial Mapping of the Canine Right Atrium: Simulation and Experiment

    Science.gov (United States)

    Sabouri, Sepideh; Matene, Elhacene; Vinet, Alain; Richer, Louis-Philippe; Cardinal, René; Armour, J. Andrew; Pagé, Pierre; Kus, Teresa; Jacquemet, Vincent

    2014-01-01

    Epicardial high-density electrical mapping is a well-established experimental instrument to monitor in vivo the activity of the atria in response to modulations of the autonomic nervous system in sinus rhythm. In regions that are not accessible by epicardial mapping, noncontact endocardial mapping performed through a balloon catheter may provide a more comprehensive description of atrial activity. We developed a computer model of the canine right atrium to compare epicardial and noncontact endocardial mapping. The model was derived from an experiment in which electroanatomical reconstruction, epicardial mapping (103 electrodes), noncontact endocardial mapping (2048 virtual electrodes computed from a 64-channel balloon catheter), and direct-contact endocardial catheter recordings were simultaneously performed in a dog. The recording system was simulated in the computer model. For simulations and experiments (after atrio-ventricular node suppression), activation maps were computed during sinus rhythm. Repolarization was assessed by measuring the area under the atrial T wave (ATa), a marker of repolarization gradients. Results showed an epicardial-endocardial correlation coefficients of 0.80 and 0.63 (two dog experiments) and 0.96 (simulation) between activation times, and a correlation coefficients of 0.57 and 0.46 (two dog experiments) and 0.92 (simulation) between ATa values. Despite distance (balloon-atrial wall) and dimension reduction (64 electrodes), some information about atrial repolarization remained present in noncontact signals. PMID:24598778

  3. Experiences of Using MATLAB/Simulink in Simulation and Control of Fluid Power Systems

    DEFF Research Database (Denmark)

    Zhou, Jianjun; Conrad, Finn; Sørensen, Torben

    1999-01-01

    MATLAB and Simulink are widely used as primary software tools in teaching and research around the word. This paper presents our experiences of using MATLAB/Simulink in simulation and control of fluid power systems. The application concerned mainly in this paper is a hydraulic test robot, shown...

  4. Simultaneous epicardial and noncontact endocardial mapping of the canine right atrium: simulation and experiment.

    Directory of Open Access Journals (Sweden)

    Sepideh Sabouri

    Full Text Available Epicardial high-density electrical mapping is a well-established experimental instrument to monitor in vivo the activity of the atria in response to modulations of the autonomic nervous system in sinus rhythm. In regions that are not accessible by epicardial mapping, noncontact endocardial mapping performed through a balloon catheter may provide a more comprehensive description of atrial activity. We developed a computer model of the canine right atrium to compare epicardial and noncontact endocardial mapping. The model was derived from an experiment in which electroanatomical reconstruction, epicardial mapping (103 electrodes, noncontact endocardial mapping (2048 virtual electrodes computed from a 64-channel balloon catheter, and direct-contact endocardial catheter recordings were simultaneously performed in a dog. The recording system was simulated in the computer model. For simulations and experiments (after atrio-ventricular node suppression, activation maps were computed during sinus rhythm. Repolarization was assessed by measuring the area under the atrial T wave (ATa, a marker of repolarization gradients. Results showed an epicardial-endocardial correlation coefficients of 0.80 and 0.63 (two dog experiments and 0.96 (simulation between activation times, and a correlation coefficients of 0.57 and 0.46 (two dog experiments and 0.92 (simulation between ATa values. Despite distance (balloon-atrial wall and dimension reduction (64 electrodes, some information about atrial repolarization remained present in noncontact signals.

  5. Simultaneous epicardial and noncontact endocardial mapping of the canine right atrium: simulation and experiment.

    Science.gov (United States)

    Sabouri, Sepideh; Matene, Elhacene; Vinet, Alain; Richer, Louis-Philippe; Cardinal, René; Armour, J Andrew; Pagé, Pierre; Kus, Teresa; Jacquemet, Vincent

    2014-01-01

    Epicardial high-density electrical mapping is a well-established experimental instrument to monitor in vivo the activity of the atria in response to modulations of the autonomic nervous system in sinus rhythm. In regions that are not accessible by epicardial mapping, noncontact endocardial mapping performed through a balloon catheter may provide a more comprehensive description of atrial activity. We developed a computer model of the canine right atrium to compare epicardial and noncontact endocardial mapping. The model was derived from an experiment in which electroanatomical reconstruction, epicardial mapping (103 electrodes), noncontact endocardial mapping (2048 virtual electrodes computed from a 64-channel balloon catheter), and direct-contact endocardial catheter recordings were simultaneously performed in a dog. The recording system was simulated in the computer model. For simulations and experiments (after atrio-ventricular node suppression), activation maps were computed during sinus rhythm. Repolarization was assessed by measuring the area under the atrial T wave (ATa), a marker of repolarization gradients. Results showed an epicardial-endocardial correlation coefficients of 0.80 and 0.63 (two dog experiments) and 0.96 (simulation) between activation times, and a correlation coefficients of 0.57 and 0.46 (two dog experiments) and 0.92 (simulation) between ATa values. Despite distance (balloon-atrial wall) and dimension reduction (64 electrodes), some information about atrial repolarization remained present in noncontact signals.

  6. A User's Guide to the Brave New World of Designing Simulation Experiments

    NARCIS (Netherlands)

    Kleijnen, J.P.C.; Sanchez, S.M.; Lucas, T.W.; Cioppa, T.M.

    2003-01-01

    Many simulation practitioners can get more from their analyses by using the statistical theory on design of experiments (DOE) developed specifically for exploring computer models.In this paper, we discuss a toolkit of designs for simulationists with limited DOE expertise who want to select a design

  7. Behavioral reactions to advanced cruise control: results of a driving simulator experiment

    NARCIS (Netherlands)

    Hoedemaeker, D.M.

    2000-01-01

    This chapter describes an experimental study that is conducted in the driving simulator at the Centre for Environmental and Traffic Psychology (COV) of the University of Groningen. In the experiment, two groups of drivers, who differed with respect to reported driving style in terms of speed, drove

  8. Experience Report: Constraint-Based Modelling and Simulation of Railway Emergency Response Plans

    DEFF Research Database (Denmark)

    Debois, Søren; Hildebrandt, Thomas; Sandberg, Lene

    2016-01-01

    We report on experiences from a case study applying a constraint-based process-modelling and -simulation tool, dcrgraphs.net, to the modelling and rehearsal of railway emergency response plans with domain experts. The case study confirmed the approach as a viable means for domain experts to analyse...

  9. The Impact of Simulation-Based Learning Experience on Critical Thinking Acquisition

    Science.gov (United States)

    Rome, Candice

    2012-01-01

    The purpose of this comparative experimental project was to compare the impact of simulation-based learning experiences to traditional clinical rotations on critical thinking acquisition of associate nursing students within a maternal-child course. Innovative pedagogies have been integrated in nursing programs to augment inadequate clinical…

  10. Event-by-event simulation of Wheeler's delayed-choice experiment

    NARCIS (Netherlands)

    Zhao, S.; Yuan, S.; De Raedt, H.; Michielsen, K.; Landau, DP; Lewis, SP; Schuttler, HB

    2010-01-01

    We present a computer simulation model of Wheeler's delayed choice experiment. The model is solely based on experimental facts and does not rely on concepts of quantum theory or probability theory. We demonstrate that it is possible to give a particle-only description of Wheeler's delayed choice

  11. Designing simulation experiments with controllable and uncontrollable factors for applications in healthcare

    DEFF Research Database (Denmark)

    Dehlendorff, Christian; Kulahci, Murat; Andersen, Klaus Kaae

    2011-01-01

    We propose a new methodology for designing computer experiments that was inspired by the split-plot designs that are often used in physical experimentation.The methodology has been developed for a simulation model of a surgical unit in a Danish hospital.We classify the factors as controllable and...

  12. Material erosion and erosion products in disruption simulation experiments at the MK-200 UG facility

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, N.I.; Bakhtin, V.P.; Kurkin, S.M.; Safronov, V.M.; Toporkov, D.A.; Vasenin, S.G.; Zhitlukhin, A.M.; Wuerz, H. E-mail: hermann.wurz@ihm.fzk.de

    2000-11-01

    Plasma/material interaction was studied in disruption simulation experiments at the plasma gun facility MK-200 UG. Graphite, tungsten and aluminium targets (beryllium-like material) were irradiated by intense plasma streams under heat fluxes typical for international thermonuclear experimental reactor (ITER) hard disruption. Materials were also exposed to radiation emitted by target plasma shields. Surface damage and erosion products were analysed.

  13. Enhancements to the Image Analysis Tool for Core Punch Experiments and Simulations (vs. 2014)

    Energy Technology Data Exchange (ETDEWEB)

    Hogden, John Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Unal, Cetin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-06

    A previous paper (Hogden & Unal, 2012, Image Analysis Tool for Core Punch Experiments and Simulations) described an image processing computer program developed at Los Alamos National Laboratory. This program has proven useful so developement has been continued. In this paper we describe enhacements to the program as of 2014.

  14. Interaction of Human and Artificial Agents on Double Auction Markets : Simulations and Laboratory Experiments

    OpenAIRE

    Grossklags, Jens; Schmidt, Carsten

    2003-01-01

    This paper provides an overview on the simulations and experiments we have done in order to better understand human-agent interaction in a market environment. We find that the introduction of software agents does not necessarily induce a more efficient market. More surprisingly, information on the existence of software agents in the market environment results in more efficient behavior of human traders.

  15. Comparison of Monte Carlo simulations of cytochrome b6f with experiment using Latin hypercube sampling.

    Science.gov (United States)

    Schumaker, Mark F; Kramer, David M

    2011-09-01

    We have programmed a Monte Carlo simulation of the Q-cycle model of electron transport in cytochrome b(6)f complex, an enzyme in the photosynthetic pathway that converts sunlight into biologically useful forms of chemical energy. Results were compared with published experiments of Kramer and Crofts (Biochim. Biophys. Acta 1183:72-84, 1993). Rates for the simulation were optimized by constructing large numbers of parameter sets using Latin hypercube sampling and selecting those that gave the minimum mean square deviation from experiment. Multiple copies of the simulation program were run in parallel on a Beowulf cluster. We found that Latin hypercube sampling works well as a method for approximately optimizing very noisy objective functions of 15 or 22 variables. Further, the simplified Q-cycle model can reproduce experimental results in the presence or absence of a quinone reductase (Q(i)) site inhibitor without invoking ad hoc side-reactions. © Society for Mathematical Biology 2011

  16. The use of SIPA 2 simulator for safety studies experience feedbacks and future developments

    International Nuclear Information System (INIS)

    Dumas, J.M.; Leteinturier, D.

    1999-01-01

    SIPA 2 experience feedbacks from the beginning of its use at IPSN in 1991 and trends for the next five years are presented. The simulator has been used for three applications: training of engineers working in safety analysis, preparation of national crisis drills, safety studies. In each application, experience feedbacks are analysed to show encountered advantages and difficulties. Trends for the next five years are: extension of the engineer training program (new training courses about normal operating conditions or about beyond design basis accidents), improvements in the validation of simulation configurations (in particular comparison with Cathare 2 new version results) increase of the simulation scope in connection with the SCAR project (taking into account the current power plant datapackage, the improvement of thermalhydraulic models, the extent of the system representation, new neutronic models and description of severe accident conditions). For each trend above, a detail of the planned actions is given. (author)

  17. Experience gained in running the EPRI MMS code with an in-house simulation language

    International Nuclear Information System (INIS)

    Weber, D.S.

    1987-01-01

    The EPRI Modular Modeling System (MMS) code represents a collection of component models and a steam/water properties package. This code has undergone extensive verification and validation testing. Currently, the code requires a commercially available simulation language to run. The Philadelphia Electric Company (PECO) has been modeling power plant systems for over the past sixteen years. As a result, an extensive number of models have been developed. In addition, an extensive amount of experience has been developed and gained using an in-house simulation language. The objective of this study was to explore the possibility of developing an MMS pre-processor which would allow the use of the MMS package with other simulation languages such as the PECO in-house simulation language

  18. Multi-physic simulations of irradiation experiments in a technological irradiation reactor

    International Nuclear Information System (INIS)

    Bonaccorsi, Th.

    2007-09-01

    A Material Testing Reactor (MTR) makes it possible to irradiate material samples under intense neutron and photonic fluxes. These experiments are carried out in experimental devices localised in the reactor core or in periphery (reflector). Available physics simulation tools only treat, most of the time, one physics field in a very precise way. Multi-physic simulations of irradiation experiments therefore require a sequential use of several calculation codes and data exchanges between these codes: this corresponds to problems coupling. In order to facilitate multi-physic simulations, this thesis sets up a data model based on data-processing objects, called Technological Entities. This data model is common to all of the physics fields. It permits defining the geometry of an irradiation device in a parametric way and to associate information about materials to it. Numerical simulations are encapsulated into interfaces providing the ability to call specific functionalities with the same command (to initialize data, to launch calculations, to post-treat, to get results,... ). Thus, once encapsulated, numerical simulations can be re-used for various studies. This data model is developed in a SALOME platform component. The first application case made it possible to perform neutronic simulations (OSIRIS reactor and RJH) coupled with fuel behavior simulations. In a next step, thermal hydraulics could also be taken into account. In addition to the improvement of the calculation accuracy due to the physical phenomena coupling, the time spent in the development phase of the simulation is largely reduced and the possibilities of uncertainty treatment are under consideration. (author)

  19. Adaptive Core Simulation Employing Discrete Inverse Theory - Part II: Numerical Experiments

    International Nuclear Information System (INIS)

    Abdel-Khalik, Hany S.; Turinsky, Paul J.

    2005-01-01

    Use of adaptive simulation is intended to improve the fidelity and robustness of important core attribute predictions such as core power distribution, thermal margins, and core reactivity. Adaptive simulation utilizes a selected set of past and current reactor measurements of reactor observables, i.e., in-core instrumentation readings, to adapt the simulation in a meaningful way. The companion paper, ''Adaptive Core Simulation Employing Discrete Inverse Theory - Part I: Theory,'' describes in detail the theoretical background of the proposed adaptive techniques. This paper, Part II, demonstrates several computational experiments conducted to assess the fidelity and robustness of the proposed techniques. The intent is to check the ability of the adapted core simulator model to predict future core observables that are not included in the adaption or core observables that are recorded at core conditions that differ from those at which adaption is completed. Also, this paper demonstrates successful utilization of an efficient sensitivity analysis approach to calculate the sensitivity information required to perform the adaption for millions of input core parameters. Finally, this paper illustrates a useful application for adaptive simulation - reducing the inconsistencies between two different core simulator code systems, where the multitudes of input data to one code are adjusted to enhance the agreement between both codes for important core attributes, i.e., core reactivity and power distribution. Also demonstrated is the robustness of such an application

  20. End-to-End Beam Simulations for the New Muon G-2 Experiment at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Korostelev, Maxim [Cockcroft Inst. Accel. Sci. Tech.; Bailey, Ian [Lancaster U.; Herrod, Alexander [Liverpool U.; Morgan, James [Fermilab; Morse, William [RIKEN BNL; Stratakis, Diktys [RIKEN BNL; Tishchenko, Vladimir [RIKEN BNL; Wolski, Andrzej [Cockcroft Inst. Accel. Sci. Tech.

    2016-06-01

    The aim of the new muon g-2 experiment at Fermilab is to measure the anomalous magnetic moment of the muon with an unprecedented uncertainty of 140 ppb. A beam of positive muons required for the experiment is created by pion decay. Detailed studies of the beam dynamics and spin polarization of the muons are important to predict systematic uncertainties in the experiment. In this paper, we present the results of beam simulations and spin tracking from the pion production target to the muon storage ring. The end-to-end beam simulations are developed in Bmad and include the processes of particle decay, collimation (with accurate representation of all apertures) and spin tracking.

  1. Computational simulation of natural circulation and rewetting experiments using the TRAC/PF1 code

    International Nuclear Information System (INIS)

    Silva, J.D. da.

    1994-05-01

    In this work the TRAC code was used to simulate experiments of natural circulation performed in the first Brazilian integral test facility at (COPESP), Sao Paulo and a rewetting experiment in a single tube test section carried out at CDTN, Belo Horizonte, Brazil. In the first simulation the loop behavior in two transient conditions with different thermal power, namely 20 k W and 120 k W, was verified in the second one the quench front propagation, the liquid mass collected in the carry over measuring tube and the wall temperature at different elevations during the flooding experiment was measured. A comparative analysis, for code consistency, shows a good agreement between the code results and experimental data, except for the quench from velocity. (author). 15 refs, 19 figs, 12 tabs

  2. Experiment and Simulation Study of Single Cylinder Diesel Engine Performance, Using Soybean Oil Biodiesel

    Directory of Open Access Journals (Sweden)

    Muhammad Rizqi Ariefianto

    2017-01-01

    Full Text Available Abstract— The most common fuel uses in the world is made from fossil. Fossil fuel is categorized as a non-renewable energy source. For that reason, there should be an alternative fuel to replace fossil fuel by using biodiesel and one of the stock comes from soybean bean. Before using the biodiesel made from soybean bean oil, there should be a research to find out the properties and the effect of biodiesel from soybean bean oil regarding the performance of the engine. The research can be conducted in experiment and simulation. The properties result of soybean oil biodiesel should be tested to confirm whether this biodiesel have meet the standard requirement of biodieselor not. This biodiesel sproperties are Flash Point value is 182 o C , Pour Point value is -7 o C, Density at 15 o C is 890 Kg/m3, Kinematic Viscosity at 40 o C is 5.58 (cSt, and Lower Heating Value is 42.27686 MJ/kg. The result from this research is the highest power from simulation is 9% higher than the experiment. The highest torque from the experiment is 37% lower than the simulation’s torque. Lowest SFOC from experiment is  28% lower than the simulation’s SFOC. Highest BMEP from simulation is 20% higher than the highest BMEP from experiment. The  highest thermal efficiency from experiment is 6% higher than the highest thermal efficiency from simulation. The engine performance result using soybean oil biodiesel is not better than the Pertamina Dex. For that reason, the use of this biodiesel is not suggested to substitute Pertamina Dex.

  3. Experiment and hydro-mechanical coupling simulation study on the human periodontal ligament.

    Science.gov (United States)

    Wei, Zhigang; Yu, Xiaoliu; Xu, Xiangrong; Chen, Xinyuan

    2014-03-01

    In this paper, a new method involving an experiment in vivo and hydro-mechanical coupling simulations was proposed to investigate the biomechanical property of human periodontal ligament (PDL). Teeth were loaded and their displacements were measured in vivo. The finite element model of the experiment was built and hydro-mechanical coupling simulations were conducted to test some PDL's constitutive models. In the simulations, the linear elastic model, the hyperfoam model, and the Ogden model were assumed for the solid phase of the PDL coupled with a model of the fluid phase of the PDL. The displacements of the teeth derived from the simulations were compared with the experimental data to validate these constitutive models. The study shows that a proposed constitutive model of the PDL can be reliably tested by this method. Furthermore, the influence of species, areas, and the fluid volume ratio on PDL's mechanical property should be considered in the modeling and simulation of the mechanical property of the PDL. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Crisis Management Simulation: Establishing a Dual Neurosurgery and Anesthesia Training Experience.

    Science.gov (United States)

    Ciporen, Jeremy; Gillham, Haley; Noles, Michele; Dillman, Dawn; Baskerville, Mark; Haley, Caleb; Spight, Donn; Turner, Ryan C; Lucke-Wold, Brandon P

    2018-01-01

    Simulation training has been shown to be an effective teaching tool. Learner management of an intraoperative crisis such as a major cerebrovascular bleed requires effective teamwork, communication, and implementation of key skill sets at appropriate time points. This study establishes a first of a kind simulation experience in a neurosurgery/anesthesia resident (learners) team working together to manage an intraoperative crisis. Using a cadaveric cavernous carotid injury perfusion model, 7 neurosurgery and 6 anesthesia learners, were trained on appropriate vascular injury management using an endonasal endoscopic technique. Learners were evaluated on communication skills, crisis management algorithms, and implementation of appropriate skill sets at the right time. A preanatomic and postanatomic examination and postsimulation survey was administered to neurosurgery learners. Anesthesia learners provided posttraining evaluation through a tailored realism and teaching survey. Neurosurgery learners' anatomic examination score improved from presimulation (33.89%) to postsimulation (86.11%). No significant difference between learner specialties was observed for situation awareness, decision making, communications and teamwork, or leadership evaluations. Learners reported the simulation realistic, beneficial, and highly instructive. Realistic, first of kind, clinical simulation scenarios were presented to a neurosurgery/anesthesia resident team who worked together to manage an intraoperative crisis. Learners were effectively trained on crisis management, the importance of communication, and how to develop algorithms for future implementation in difficult scenarios. Learners were highly satisfied with the simulation training experience and requested that it be integrated more consistently into their residency training programs.

  5. The Chemistry of Shocked High-energy Materials: Connecting Atomistic Simulations to Experiments

    Science.gov (United States)

    Islam, Md Mahbubul; Strachan, Alejandro

    2017-06-01

    A comprehensive atomistic-level understanding of the physics and chemistry of shocked high energy (HE) materials is crucial for designing safe and efficient explosives. Advances in the ultrafast spectroscopy and laser shocks enabled the study of shock-induced chemistry at extreme conditions occurring at picosecond timescales. Despite this progress experiments are not without limitations and do not enable a direct characterization of chemical reactions. At the same time, large-scale reactive molecular dynamics (MD) simulations are capable of providing description of the shocked-induced chemistry but the uncertainties resulting from the use of approximate descriptions of atomistic interactions remain poorly quantified. We use ReaxFF MD simulations to investigate the shock and temperature induced chemical decomposition mechanisms of polyvinyl nitrate, RDX, and nitromethane. The effect of various shock pressures on reaction initiation mechanisms is investigated for all three materials. We performed spectral analysis from atomistic velocities at different shock pressures to enable direct comparison with experiments. The simulations predict volume-increasing reactions at the shock-to-detonation transitions and the shock vs. particle velocity data are in good agreement with available experimental data. The ReaxFF MD simulations validated against experiments enabled prediction of reaction kinetics of shocked materials, and interpretation of experimental spectroscopy data via assignment of the spectral peaks to dictate various reaction pathways at extreme conditions.

  6. New method of processing heat treatment experiments with numerical simulation support

    Science.gov (United States)

    Kik, T.; Moravec, J.; Novakova, I.

    2017-08-01

    In this work, benefits of combining modern software for numerical simulations of welding processes with laboratory research was described. Proposed new method of processing heat treatment experiments leading to obtaining relevant input data for numerical simulations of heat treatment of large parts was presented. It is now possible, by using experiments on small tested samples, to simulate cooling conditions comparable with cooling of bigger parts. Results from this method of testing makes current boundary conditions during real cooling process more accurate, but also can be used for improvement of software databases and optimization of a computational models. The point is to precise the computation of temperature fields for large scale hardening parts based on new method of temperature dependence determination of the heat transfer coefficient into hardening media for the particular material, defined maximal thickness of processed part and cooling conditions. In the paper we will also present an example of the comparison standard and modified (according to newly suggested methodology) heat transfer coefficient data’s and theirs influence on the simulation results. It shows how even the small changes influence mainly on distribution of temperature, metallurgical phases, hardness and stresses distribution. By this experiment it is also possible to obtain not only input data and data enabling optimization of computational model but at the same time also verification data. The greatest advantage of described method is independence of used cooling media type.

  7. Brownfield Action: An education through an environmental science simulation experience for undergraduates

    Science.gov (United States)

    Kelsey, Ryan Daniel

    Brownfield Action is a computer simulation experience used by undergraduates in an Introduction to Environmental Science course for non-science majors at Barnard College. Students play the role of environmental consultants given the semester-long task of investigating a potentially contaminated landsite in a simulated town. The simulation serves as the integration mechanism for the entire course. The project is a collaboration between Professor Bower and the Columbia University Center for New Media Teaching and Learning (CCNMTL). This study chronicles the discovery, design, development, implementation, and evaluation of this project over its four-year history from prototype to full-fledged semester-long integrated lecture and lab experience. The complete project history serves as a model for the development of best practices in contributing to the field of educational technology in higher education through the study of fully designed and implemented projects in real classrooms. Recommendations from the project focus on linking the laboratory and lecture portions of a course, the use of simulations (especially for novice students), instructor adaptation to the use of technology, general educational technology project development, and design research, among others. Findings from the study also emphasize the uniqueness of individual student's growth through the experience, and the depth of understanding that can be gained from embracing the complexity of studying sophisticated learning environments in real classrooms.

  8. Are water simulation models consistent with steady-state and ultrafast vibrational spectroscopy experiments?

    International Nuclear Information System (INIS)

    Schmidt, J.R.; Roberts, S.T.; Loparo, J.J.; Tokmakoff, A.; Fayer, M.D.; Skinner, J.L.

    2007-01-01

    Vibrational spectroscopy can provide important information about structure and dynamics in liquids. In the case of liquid water, this is particularly true for isotopically dilute HOD/D 2 O and HOD/H 2 O systems. Infrared and Raman line shapes for these systems were measured some time ago. Very recently, ultrafast three-pulse vibrational echo experiments have been performed on these systems, which provide new, exciting, and important dynamical benchmarks for liquid water. There has been tremendous theoretical effort expended on the development of classical simulation models for liquid water. These models have been parameterized from experimental structural and thermodynamic measurements. The goal of this paper is to determine if representative simulation models are consistent with steady-state, and especially with these new ultrafast, experiments. Such a comparison provides information about the accuracy of the dynamics of these simulation models. We perform this comparison using theoretical methods developed in previous papers, and calculate the experimental observables directly, without making the Condon and cumulant approximations, and taking into account molecular rotation, vibrational relaxation, and finite excitation pulses. On the whole, the simulation models do remarkably well; perhaps the best overall agreement with experiment comes from the SPC/E model

  9. Experiment and simulation of superconducting magnetic levitation with REBCO coated conductor stacks

    Science.gov (United States)

    Liu, Kun; Yang, Wenjiao; Ma, Guangtong; Quéval, Loïc; Gong, Tianyong; Ye, Changqing; Li, Xiang; Luo, Zhen

    2018-01-01

    Three superconducting stacks made of 120 REBCO coated conductor tapes were each fabricated and assembled to obtain several REBCO modules. Their levitation responses over two different permanent magnet (PM) guideways were investigated by experiment and finite element simulation. For the experiment, a test rig was developed that can measure the force in the three directions for any given relative movement between the REBCO stacks and the PM guideway. For the finite element simulation, a 2D H-formulation was adopted. To treat the high aspect ratio of REBCO tapes, an anisotropic homogenization technique was used. The agreement between the measurements and the simulations is good, thus validating the modeling methodology. It was observed from the experiment and simulation results that the perpendicular field contributes to the levitation force whereas the parallel field is responsible for the guidance force, as a result of the existence of anisotropy on the local magnetic stimulation. Based on that, promising REBCO modules including both longitudinal and transverse arrangements of REBCO stacks were proposed and tested, in terms of providing a significant levitation force with the lateral stability preserved. Moreover, a pre-load process able to suppress the relaxation of the levitation force was put forward. To conclude, this study outlines explicit principles to obtain an appropriate layout of coated conductor stacks that could be effective for practical magnetic levitation operation.

  10. Haptic feedback improves surgeons' user experience and fracture reduction in facial trauma simulation.

    Science.gov (United States)

    Girod, Sabine; Schvartzman, Sara C; Gaudilliere, Dyani; Salisbury, Kenneth; Silva, Rebeka

    2016-01-01

    Computer-assisted surgical (CAS) planning tools are available for craniofacial surgery, but are usually based on computer-aided design (CAD) tools that lack the ability to detect the collision of virtual objects (i.e., fractured bone segments). We developed a CAS system featuring a sense of touch (haptic) that enables surgeons to physically interact with individual, patient-specific anatomy and immerse in a three-dimensional virtual environment. In this study, we evaluated initial user experience with our novel system compared to an existing CAD system. Ten surgery resident trainees received a brief verbal introduction to both the haptic and CAD systems. Users simulated mandibular fracture reduction in three clinical cases within a 15 min time limit for each system and completed a questionnaire to assess their subjective experience. We compared standard landmarks and linear and angular measurements between the simulated results and the actual surgical outcome and found that haptic simulation results were not significantly different from actual postoperative outcomes. In contrast, CAD results significantly differed from both the haptic simulation and actual postoperative results. In addition to enabling a more accurate fracture repair, the haptic system provided a better user experience than the CAD system in terms of intuitiveness and self-reported quality of repair.

  11. Direct comparison of elastic incoherent neutron scattering experiments with molecular dynamics simulations of DMPC phase transitions.

    Science.gov (United States)

    Aoun, Bachir; Pellegrini, Eric; Trapp, Marcus; Natali, Francesca; Cantù, Laura; Brocca, Paola; Gerelli, Yuri; Demé, Bruno; Marek Koza, Michael; Johnson, Mark; Peters, Judith

    2016-04-01

    Neutron scattering techniques have been employed to investigate 1,2-dimyristoyl-sn -glycero-3-phosphocholine (DMPC) membranes in the form of multilamellar vesicles (MLVs) and deposited, stacked multilamellar-bilayers (MLBs), covering transitions from the gel to the liquid phase. Neutron diffraction was used to characterise the samples in terms of transition temperatures, whereas elastic incoherent neutron scattering (EINS) demonstrates that the dynamics on the sub-macromolecular length-scale and pico- to nano-second time-scale are correlated with the structural transitions through a discontinuity in the observed elastic intensities and the derived mean square displacements. Molecular dynamics simulations have been performed in parallel focussing on the length-, time- and temperature-scales of the neutron experiments. They correctly reproduce the structural features of the main gel-liquid phase transition. Particular emphasis is placed on the dynamical amplitudes derived from experiment and simulations. Two methods are used to analyse the experimental data and mean square displacements. They agree within a factor of 2 irrespective of the probed time-scale, i.e. the instrument utilized. Mean square displacements computed from simulations show a comparable level of agreement with the experimental values, albeit, the best match with the two methods varies for the two instruments. Consequently, experiments and simulations together give a consistent picture of the structural and dynamical aspects of the main lipid transition and provide a basis for future, theoretical modelling of dynamics and phase behaviour in membranes. The need for more detailed analytical models is pointed out by the remaining variation of the dynamical amplitudes derived in two different ways from experiments on the one hand and simulations on the other.

  12. Simultaneous ion and neutral evaporation in aqueous nanodrops: experiment, theory, and molecular dynamics simulations.

    Science.gov (United States)

    Higashi, Hidenori; Tokumi, Takuya; Hogan, Christopher J; Suda, Hiroshi; Seto, Takafumi; Otani, Yoshio

    2015-06-28

    We use a combination of tandem ion mobility spectrometry (IMS-IMS, with differential mobility analyzers), molecular dynamics (MD) simulations, and analytical models to examine both neutral solvent (H2O) and ion (solvated Na(+)) evaporation from aqueous sodium chloride nanodrops. For experiments, nanodrops were produced via electrospray ionization (ESI) of an aqueous sodium chloride solution. Two nanodrops were examined in MD simulations: a 2500 water molecule nanodrop with 68 Na(+) and 60 Cl(-) ions (an initial net charge of z = +8), and (2) a 1000 water molecule nanodrop with 65 Na(+) and 60 Cl(-) ions (an initial net charge of z = +5). Specifically, we used MD simulations to examine the validity of a model for the neutral evaporation rate incorporating both the Kelvin (surface curvature) and Thomson (electrostatic) influences, while both MD simulations and experimental measurements were compared to predictions of the ion evaporation rate equation of Labowsky et al. [Anal. Chim. Acta, 2000, 406, 105-118]. Within a single fit parameter, we find excellent agreement between simulated and modeled neutral evaporation rates for nanodrops with solute volume fractions below 0.30. Similarly, MD simulation inferred ion evaporation rates are in excellent agreement with predictions based on the Labowsky et al. equation. Measurements of the sizes and charge states of ESI generated NaCl clusters suggest that the charge states of these clusters are governed by ion evaporation, however, ion evaporation appears to have occurred with lower activation energies in experiments than was anticipated based on analytical calculations as well as MD simulations. Several possible reasons for this discrepancy are discussed.

  13. Evolution and experience with the ATLAS simulation at Point1 project

    CERN Document Server

    Ballestrero, Sergio; The ATLAS collaboration; Fazio, Daniel; Di Girolamo, Alessandro; Kouba, Tomas; Lee, Christopher; Scannicchio, Diana; Schovancova, Jaroslava; Twomey, Matthew Shaun; Wang, Fuquan; Zaytsev, Alexander

    2016-01-01

    The Simulation at Point1 project is successfully running traditional ATLAS simulation jobs on the TDAQ HLT resources. The pool of available resources changes dynamically, therefore we need to be very effective in exploiting the available computing cycles. We will present our experience with using the Event Service that provides the event-level granularity of computations. We will show the design decisions and overhead time related to the usage of the Event Service. The improved utilization of the resources will also be presented with the recent development in monitoring, automatic alerting, deployment and GUI.

  14. Evolution and experience with the ATLAS Simulation at Point1 Project

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00389536; The ATLAS collaboration; Brasolin, Franco; Kouba, Tomas; Schovancova, Jaroslava; Fazio, Daniel; Di Girolamo, Alessandro; Scannicchio, Diana; Twomey, Matthew Shaun; Wang, Fuquan; Zaytsev, Alexander; Lee, Christopher

    2017-01-01

    The Simulation at Point1 project is successfully running standard ATLAS simulation jobs on the TDAQ HLT resources. The pool of available resources changes dynamically, therefore we need to be very effective in exploiting the available computing cycles. We present our experience with using the Event Service that provides the event-level granularity of computations. We show the design decisions and overhead time related to the usage of the Event Service. The improved utilization of the resources is also presented with the recent development in monitoring, automatic alerting, deployment and GUI.

  15. Experiment and simulation studies on SPEEK PEM with different sulfonation degrees

    Science.gov (United States)

    Wang, Rujie; Li, Ming

    2017-04-01

    Effects of degrees of sulfonation (DS) on the cluster aggregation, proton conductivity and mechanical properties of sulfonated poly ether ether ketone (SPEEK) proton exchange membranes (PEMs) were investigated by experiment and simulation studies. SPEEK materials with different DS and the corresponding PEMs had been prepared by sulfonation and solution casting. The water uptake, swelling ratio, proton conductivity and mechanical properties of SPEEK PEMs were greatly affected by DS. And the hydrophilic cluster aggregation in SPEEK of different DS was revealed by molecular simulation. The relationship between structure and performance of SPEEK membrane provides theoretical guidance for the preparation of high performance proton exchange membranes.

  16. A gas puff experiment for partial simulation of compact toroid formation on MARAUDER

    International Nuclear Information System (INIS)

    Englert, S.E.; Englert, T.J.; Degnan, J.H.; Gahl, J.M.

    1994-01-01

    Preliminary results will be reported of a single valve gas puff experiment to determine spatial and spectral distribution of a gas during the early ionization stages. This experiment has been developed as a diagnostic test-bed for partial simulation of compact toroid formation on MARAUDER. The manner in which the experimental hardware has been designed allows for a wide range of diagnostic access to evaluate early time evolution of the ionization process. This evaluation will help contribute to a clearer understanding of the initial conditions for the formation stage of the compact toroid in the MARAUDER experiment, where 60 of the same puff valves are used. For the experiment, a small slice of the MARAUDER cylindrical gas injection and expansion region geometry have been re-created but in cartesian coordinates. All of the conditions in the experiment adhere as closely as possible to the MARAUDER experiment. The timing, current rise time, capacitance, resistance and inductance are appropriate to both the simulation of one of the 60 puff valves and current delivery to the load. Both time-resolved images and spectral data have been gathered for visible light emission of the plasma. Processed images reveal characteristics of spatial distribution of the current. Spectral data provide information with respect to electron temperature and density, and entrainment of contaminants

  17. Learning style and laparoscopic experience in psychomotor skill performance using a virtual reality surgical simulator.

    Science.gov (United States)

    Windsor, John A; Diener, Scott; Zoha, Farah

    2008-06-01

    People learn in different ways, and training techniques and technologies should accommodate individual learning needs. This pilot study looks at the relationship between learning style, as measured with the Multiple Intelligences Developmental Assessment Scales (MIDAS), laparoscopic surgery experience and psychomotor skill performance using the MIST VR surgical simulator. Five groups of volunteer subjects were selected from undergraduate tertiary students, medical students, novice surgical trainees, advanced surgical trainees and experienced laparoscopic surgeons. Each group was administered the MIDAS followed by two simulated surgical tasks on the MIST VR simulator. There was a striking homogeny of learning styles amongst experienced laparoscopic surgeons. Significant differences in the distribution of primary learning styles were found (P < .01) between subjects with minimal surgical training and those with considerable experience. A bodily-kinesthetic learning style, irrespective of experience, was associated with the best performance of the laparoscopic tasks. This is the first study to highlight the relationship between learning style, psychomotor skill and laparoscopic surgical experience with implications for surgeon selection, training and credentialling.

  18. Development and successful operation of the enhanced-interlink system of experiment data and numerical simulation in LHD

    International Nuclear Information System (INIS)

    Emoto, M.; Suzuki, C.; Suzuki, Y.; Yokoyama, M.; Seki, R.; Ida, K.

    2014-10-01

    The enhanced-interlink system of experiment data and numerical simulation has been developed, and successfully operated routinely in the Large Helical Device (LHD). This system consists of analyzed diagnostic data, real-time coordinate mapping, and automatic data processing. It has enabled automated data handling/transferring between experiment and numerical simulation, to extensively perform experiment analyses. It can be considered as one of the prototypes for a seamless data-centric approach for integrating experiment data and numerical simulation/modellings in fusion experiments. Utilizing this system, experimental analyses by numerical simulations have extensively progressed. The authors believe this data-centric approach for integrating experiment data and numerical simulation/modellings will contribute to not only the LHD but to other plasma fusion projects including DEMO reactor in the future. (author)

  19. Experiments with the Mesoscale Atmospheric Simulation System (MASS) using the synthetic relative humidity

    Science.gov (United States)

    Chang, Chia-Bo

    1994-01-01

    This study is intended to examine the impact of the synthetic relative humidity on the model simulation of mesoscale convective storm environment. The synthetic relative humidity is derived from the National Weather Services surface observations, and non-conventional sources including aircraft, radar, and satellite observations. The latter sources provide the mesoscale data of very high spatial and temporal resolution. The synthetic humidity data is used to complement the National Weather Services rawinsonde observations. It is believed that a realistic representation of initial moisture field in a mesoscale model is critical for the model simulation of thunderstorm development, and the formation of non-convective clouds as well as their effects on the surface energy budget. The impact will be investigated based on a real-data case study using the mesoscale atmospheric simulation system developed by Mesoscale Environmental Simulations Operations, Inc. The mesoscale atmospheric simulation system consists of objective analysis and initialization codes, and the coarse-mesh and fine-mesh dynamic prediction models. Both models are a three dimensional, primitive equation model containing the essential moist physics for simulating and forecasting mesoscale convective processes in the atmosphere. The modeling system is currently implemented at the Applied Meteorology Unit, Kennedy Space Center. Two procedures involving the synthetic relative humidity to define the model initial moisture fields are considered. It is proposed to perform several short-range (approximately 6 hours) comparative coarse-mesh simulation experiments with and without the synthetic data. They are aimed at revealing the model sensitivities should allow us both to refine the specification of the observational requirements, and to develop more accurate and efficient objective analysis schemes. The goal is to advance the MASS (Mesoscal Atmospheric Simulation System) modeling expertise so that the model

  20. Natural circulation in a VVER reactor geometry: Experiments with the PACTEL facility and Cathare simulations

    Energy Technology Data Exchange (ETDEWEB)

    Raussi, P.; Kainulainen, S. [Lappeenranta Univ. of Technology, Lappeenranta (Finland); Kouhia, J. [VTT Energy, Lappeenranta (Finland)

    1995-09-01

    There are some 40 reactors based on the VVER design in use. Database available for computer code assessment for VVER reactors is rather limited. Experiments were conducted to study natural circulation behaviour in the PACTEL facility, a medium-scale integral test loop patterned after VVER pressurized water reactors. Flow behaviour over a range of coolant inventories was studied with a small-break experiment. In the small-break experiments, flow stagnation and system repressurization were observed when the water level in the upper plenum fell below the entrances to the hot legs. The cause was attributed to the hot leg loop seals, which are a unique feature of the VVER geometry. At low primary inventories, core cooling was achieved through the boiler-condenser mode. The experiment was simulated using French thermalhydraulic system code CATHARE.

  1. Clarifying the learning experiences of healthcare professionals with in situ and off-site simulation-based medical education

    DEFF Research Database (Denmark)

    Sørensen, Jette Led; Navne, Laura Emdal; Martin, Helle Max

    2015-01-01

    OBJECTIVE: To examine how the setting in in situ simulation (ISS) and off-site simulation (OSS) in simulation-based medical education affects the perceptions and learning experience of healthcare professionals. DESIGN: Qualitative study using focus groups and content analysis. PARTICIPANTS: Twenty...

  2. Training simulators in nuclear power plants: Experience, programme design and assessment methodology. Proceedings of a specialists' meeting

    International Nuclear Information System (INIS)

    1997-11-01

    Simulators became an indispensable part of training world-wide. Therefore, international exchange of information is important to share the experience gained in different countries in order to assure high international standards. A second aspects is the tremendous evolution in the computing capacities of the simulator hardware and the increasing functionality of the simulator software. This background has let the IAEA to invite the simulator experts for an experience exchange. The German Simulator Centre in Essen, which is operated by the companies KSG and GfS, was asked to host this Specialists' Meeting. The Specialists' Meeting on ''Training Simulators in Nuclear Power Plants: Experience, Programme Design and Assessment Methodology'' was organized by IAEA in-cooperation with the German Simulator Centre operated by KSG Kraftwerks-Simulator-Gesellschaft mbH and GfS Gesellschaft fuer Simulatorschulung mbH and was held from 17 - 19 November 1997 in Essen, Germany. The meeting focused on developments in simulation technology, experiences with simulator upgrades, utilization of computerized tools as support and complement of simulator training, use of simulators for other purposes. The meeting was attended by 50 participants from 16 countries. In the course of four sessions 21 technical presentations were made. The present volume contains the papers by national delegates at the Specialists' Meeting

  3. SIMULATIONS AND GAMES IN MANAGEMENT EDUCATION: TOWARDS A MULTI-DIMENSIONAL EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Jorge Paulo Sequeira

    2013-06-01

    Full Text Available Games and simulations have been used in the field of education for many years, particularly in the areas of business, training staff in financial and economic skills, combat training and war gaming. Internet-based games are also commonly used in the areas of education, business and policy to provide a safe but realistic experience of the real world. This paper explores some of the rationale that a team of lecturers at the Lisbon School of Accounting and Administration (ISCAL think should underpin simulation and game usage in an educational context, specifically in management education. Our aim with this work is about promoting learning and knowledge building through one of the latest evolved socio-cultural artifact: online simulations and games.

  4. Flocking and self-defense: experiments and simulations of avian mobbing

    Science.gov (United States)

    Kane, Suzanne Amador

    2011-03-01

    We have performed motion capture studies in the field of avian mobbing, in which flocks of prey birds harass predatory birds. Our empirical studies cover both field observations of mobbing occurring in mid-air, where both predator and prey are in flight, and an experimental system using actual prey birds and simulated predator ``perch and wait'' strategies. To model our results and establish the effectiveness of mobbing flight paths at minimizing risk of capture while optimizing predator harassment, we have performed computer simulations using the actual measured trajectories of mobbing prey birds combined with model predator trajectories. To accurately simulate predator motion, we also measured raptor acceleration and flight dynamics, well as prey-pursuit strategies. These experiments and theoretical studies were all performed with undergraduate research assistants in a liberal arts college setting. This work illustrates how biological physics provides undergraduate research projects well-suited to the abilities of physics majors with interdisciplinary science interests and diverse backgrounds.

  5. Study on numerical analysis and experiment simulation approaches for radiation effects of typical optoelectronic devices

    International Nuclear Information System (INIS)

    Tang Benqi; Zhang Yong; Xiao Zhigang; Huang Fang; Wang Zujun; Huang Shaoyan; Mao Yongze; Wang Feng

    2005-01-01

    The numerical analysis and experimental simulation approaches were studied for radiation effects of typical optoelectronic devices, such as Si solar cells and CCDs. At first, the damage mechanism of ionization and displacement effects on solar cells and CCDs was analyzed. Secondly, the output characteristics of Si solar cell by 1 MeV electron radiation was calculated with the two-dimensional device simulation software MEDICI, such as the short circuit current I sc , the open-circuit voltage V oc and the maximum power P max . The simulation results are in good agreement with the experimental values in a certain range of electron fluence. Meanwhile, the ionization radiation experiment was carried out on the commercial linear CCD by 60 Co γ source with our self-designed test system, and some valuable results of dark voltage and saturation voltage varied with total dose for TCD132D were gotten. (author)

  6. Nonlinear gyrokinetic simulations of the I-mode high confinement regime and comparisons with experiment

    Energy Technology Data Exchange (ETDEWEB)

    White, A. E., E-mail: whitea@mit.edu; Howard, N. T.; Creely, A. J.; Chilenski, M. A.; Greenwald, M.; Hubbard, A. E.; Hughes, J. W.; Marmar, E.; Rice, J. E.; Sierchio, J. M.; Sung, C.; Walk, J. R.; Whyte, D. G. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Mikkelsen, D. R.; Edlund, E. M.; Kung, C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Holland, C. [University of California, San Diego (UCSD) San Diego, California 92093 (United States); Candy, J.; Petty, C. C. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States); Reinke, M. L. [York University, Heslington, York YO10 5DD (United Kingdom); and others

    2015-05-15

    For the first time, nonlinear gyrokinetic simulations of I-mode plasmas are performed and compared with experiment. I-mode is a high confinement regime, featuring energy confinement similar to H-mode, but without enhanced particle and impurity particle confinement [D. G. Whyte et al., Nucl. Fusion 50, 105005 (2010)]. As a consequence of the separation between heat and particle transport, I-mode exhibits several favorable characteristics compared to H-mode. The nonlinear gyrokinetic code GYRO [J. Candy and R. E. Waltz, J Comput. Phys. 186, 545 (2003)] is used to explore the effects of E × B shear and profile stiffness in I-mode and compare with L-mode. The nonlinear GYRO simulations show that I-mode core ion temperature and electron temperature profiles are more stiff than L-mode core plasmas. Scans of the input E × B shear in GYRO simulations show that E × B shearing of turbulence is a stronger effect in the core of I-mode than L-mode. The nonlinear simulations match the observed reductions in long wavelength density fluctuation levels across the L-I transition but underestimate the reduction of long wavelength electron temperature fluctuation levels. The comparisons between experiment and gyrokinetic simulations for I-mode suggest that increased E × B shearing of turbulence combined with increased profile stiffness are responsible for the reductions in core turbulence observed in the experiment, and that I-mode resembles H-mode plasmas more than L-mode plasmas with regards to marginal stability and temperature profile stiffness.

  7. Boron carbide: hydrocode simulation of plate-impact experiments with an improved failure model

    Science.gov (United States)

    Dyachkov, Sergey; Parshikov, Anatoly; Zhakhovsky, Vasily

    2017-06-01

    Unique strength properties of boron carbide make it useful for numerous applications. However, shock compression accompanied by high strains rates involves material into the process of failure what significantly reduces its strength. In this research we compare simulation results for two sets of plate-impact experiments where samples were manufactured using different technology. Simulations are performed using our 3D SPH hydrocode and the improved Johnson-Holmquist failure model. Complex wave profiles obtained via VISAR are properly reproduced in our modeling. However, it was found that the failed boron carbide strength have a strong effect on the wave profiles and should be different for the each set of experiments. Moreover, heterogeneous distribution of failed boron carbide is shown to affect wave propagation to the rear surface of sample what results in spatial velocity profile variations obtained via line-VISAR system.

  8. Simulation of Charged Particle Trajectories in the Neutron Decay Correlation Experiment abBA.

    Science.gov (United States)

    Desai, Dharmin; Greene, Geoffrey; Mahurin, Rob; Bowman, David; Calarco, John

    2005-01-01

    The proposed neutron decay correlation experiment, abBA, will directly detect the direction of emission of decay protons and electrons as well as providing spectroscopic information for both particles. In order to provide this information, the abBA experiment incorporates spatially varying electric and magnetic fields. We report on detailed simulations of the decay particle trajectories in order to assess the impact of various systematic effects on the experimental observables. These include among others; adiabaticity of particle orbits, tracking of orbits, reversal of low energy protons due to inhomogeneous electric field, and accuracy of proton time of flight measurements. Several simulation methods were used including commercial software (Simion), custom software, as well as analytical tools based on the use of adiabatic invariants. Our results indicate that the proposed field geometry of the abBA spectrometer will be substantially immune to most systematic effects and that transport calculations using adiabatic invariants agree well with solution of the full equations of motion.

  9. Development of Laser-Induced Fluorescence Diagnostic for the Paul Trap Simulator Experiment

    CERN Document Server

    Chung, Moses; Efthimion, Philip; Gilson, Erik P; Majeski, Richard; Startsev, Edward

    2005-01-01

    The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation in alternating-gradient magnetic transport systems. For the in-situ measurement of the transverse ion density profile in the PTSX device, which is essential for the study of beam mismatch and halo particle production, a laser-induced fluorescence diagnostic system is being developed. Instead of cesium, which has been used in the initial phase of the PTSX experiment, barium has been selected as the preferred ion for the laser-induced fluorescence diagnostic. The installation of the barium ion source and the characterization of the tunable dye laser system are discussed. The design of the collection optics with an intensified CCD camera system is also discussed. Finally, initial test results using the laser-induced fluorescence diagnostic will be presented.

  10. Adsorption of probe molecules in pillared interlayered clays: Experiment and computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, A., E-mail: a.gallardo@iqfr.csic.es; Guil, J. M.; Lomba, E.; Almarza, N. G.; Khatib, S. J. [Instituto de Química Física Rocasolano, CSIC, Serrano 119, E-28006 Madrid (Spain); Cabrillo, C.; Sanz, A. [Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain); Pires, J. [Centro de Química e Bioquímica da Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa (Portugal)

    2014-06-14

    In this paper we investigate the adsorption of various probe molecules in order to characterize the porous structure of a series of pillared interlayered clays (PILC). To that aim, volumetric and microcalorimetric adsorption experiments were performed on various Zr PILC samples using nitrogen, toluene, and mesitylene as probe molecules. For one of the samples, neutron scattering experiments were also performed using toluene as adsorbate. Various structural models are proposed and tested by means of a comprehensive computer simulation study, using both geometric and percolation analysis in combination with Grand Canonical Monte Carlo simulations in order to model the volumetric and microcalorimetric isotherms. On the basis of this analysis, we propose a series of structural models that aim at accounting for the adsorption experimental behavior, and make possible a microscopic interpretation of the role played by the different interactions and steric effects in the adsorption processes in these rather complex disordered microporous systems.

  11. Monte-Carlo Geant4 numerical simulation of experiments at 247-MeV proton microscope

    Science.gov (United States)

    Kantsyrev, A. V.; Skoblyakov, A. V.; Bogdanov, A. V.; Golubev, A. A.; Shilkin, N. S.; Yuriev, D. S.; Mintsev, V. B.

    2018-01-01

    A radiographic facility for an investigation of fast dynamic processes with areal density of targets up to 5 g/cm2 is under development on the basis of high-current proton linear accelerator at the Institute for Nuclear Research (Troitsk, Russia). A virtual model of the proton microscope developed in a software toolkit Geant4 is presented in the article. Fullscale Monte-Carlo numerical simulation of static radiographic experiments at energy of a proton beam 247 MeV was performed. The results of simulation of proton radiography experiments with static model of shock-compressed xenon are presented. The results of visualization of copper and polymethyl methacrylate step wedges static targets also described.

  12. Recent Results of ICC Experiment Simulations by the PSI-Center

    Science.gov (United States)

    Nelson, B. A.; Glasser, A. H.; Jarboe, T. R.; Kim, C. C.; Marklin, G. J.; Lowrie, W.; Meier, E. T.; Milroy, R. D.; Shumlak, U.; Sovinec, C. R.; O'Bryan, J. B.; Held, E.; Ji, J.-Y.; Lukin, V. S.

    2010-11-01

    The Plasma Science and Innovation Center (PSI-Center - http://www.psicenter.org) performs simulations of collaborating Innovative Confinement Concept (ICC) experiments. Collaborators include the Bellan Plasma Group (Caltech), CTH (Auburn U), FRX-L (Los Alamos National Laboratory), HIT-SI (U Wash - UW), LDX (M.I.T.), MST & Pegasus (U Wisc-Madison), PHD (UW), PFRC (PPPL), SSX (Swarthmore College), TCS (UW), and ZaP (UW). Modifications have been made to the NIMROD, HiFi, and PSI-Tet codes to specifically model these ICC experiments, including mesh generation/refinement, appropriate boundary conditions (external fields, insulating BCs, etc.), and kinetic and neutral particle interactions. Output files from these codes are interfaced to the powerful 3-D visualization program, VisIt (http://www.llnl.gov/visit). Results from these simulations, as well as an overview of the Interfacing Group status will be presented.

  13. Nuclear models, experiments and data libraries needed for numerical simulation of accelerator-driven system

    International Nuclear Information System (INIS)

    Bauge, E.; Bersillon, O.

    2000-01-01

    This paper presents the transparencies of the speech concerning the nuclear models, experiments and data libraries needed for numerical simulation of Accelerator-Driven Systems. The first part concerning the nuclear models defines the spallation process, the corresponding models (intra-nuclear cascade, statistical model, Fermi breakup, fission, transport, decay and macroscopic aspects) and the code systems. The second part devoted to the experiments presents the angular measurements, the integral measurements, the residual nuclei and the energy deposition. In the last part, dealing with the data libraries, the author details the fundamental quantities as the reaction cross-section, the low energy transport databases and the decay libraries. (A.L.B.)

  14. Nuclear waste repository simulation experiments, Asse Salt Mine, Federal Republic of Germany. Annual report, 1983

    International Nuclear Information System (INIS)

    Rothfuchs, T.; Luebker, D.; Coyle, A.; Kalia, H.

    1984-10-01

    This is the First Annual report (1983) which describes experiments simulating a nuclear waste respository at the 800-meter level of the Asse Salt Mine in the Federal Republic of Germany. The report describes the test equipment, the Asse Salt Mine, the pretest properties of the salt in the test gallery, and the mine proper. Also included are test data for the first six months of operations on brine migration rates, room closure rates, extensometer readings, stress measurements, and thermal mechanical behavior of the salt. The duration of the experiments will be two years, ending in December 1985. 3 references, 34 figures, 13 tables

  15. Disruption simulation experiment using high-frequency rastering electron beam as the heat source

    International Nuclear Information System (INIS)

    Yamazaki, S.; Seki, M.

    1987-01-01

    The disruption is a serious event which possibly reduces the lifetime of plasm interactive components, so the effects of the resulting high heat flux on the wall materials must be clearly identified. The authors performed disruption simulation experiments to investigate melting, evaporation, and crack initiation behaviors using an electron beam facility as the heat source. The facility was improved with a high-frequency beam rastering system which provided spatially and temporally uniform heat flux on wider test surfaces. Along with the experiments, thermal and mechanical analyses were also performed. A two-dimensional disruption thermal analysis code (DREAM) was developed for the analyses

  16. Evaluation of the Trac-PF1 code for simulating the Neptun reflooding experiment

    International Nuclear Information System (INIS)

    Pontedeiro, A.C.; Galetti, M.R.S.

    1991-01-01

    The present work presents an assessment of the TRAC-BF1 code using the results of the NEPTUN experiment which simulates the reflooding in a loss-of-coolant accident (LOCA) in a PWR. The NEPTUN experiment is composed of an array of electrically-heated tubes where the reflooding condition can be tested. Two types of tests results are presented and compared with the values obtained with the TRAC-BF1 code. From this comparison it is concluded that TRAC is suitable for verifying accident analysis. (author)

  17. Experiment and Simulation Effects of Cyclic Pitch Control on Performance of Horizontal Axis Wind Turbine

    Directory of Open Access Journals (Sweden)

    Le Quang Sang

    2017-06-01

      Keywords: Floating Offshore Wind Turbine, Aerodynamic Forces, Cyclic Pitch Control, FAST Code, Wind Tunnel Experiment Article History: Received February 11th 2017; Received in revised form April 29th 2017; Accepted June 2nd 2017; Available online How to Cite This Article: Sang, L.Q., Maeda, T., Kamada, Y., and Li, Q. (2017 Experiment and simulation effect of cyclic pitch control on performance of horizontal axis wind turbine to International Journal of Renewable Energy Develeopment, 6(2, 119-125. https://doi.org/10.14710/ijred.6.2.119-125

  18. NASA Virtual Glovebox (VBX): Emerging Simulation Technology for Space Station Experiment Design, Development, Training and Troubleshooting

    Science.gov (United States)

    Smith, Jeffrey D.; Twombly, I. Alexander; Maese, A. Christopher; Cagle, Yvonne; Boyle, Richard

    2003-01-01

    The International Space Station demonstrates the greatest capabilities of human ingenuity, international cooperation and technology development. The complexity of this space structure is unprecedented; and training astronaut crews to maintain all its systems, as well as perform a multitude of research experiments, requires the most advanced training tools and techniques. Computer simulation and virtual environments are currently used by astronauts to train for robotic arm manipulations and extravehicular activities; but now, with the latest computer technologies and recent successes in areas of medical simulation, the capability exists to train astronauts for more hands-on research tasks using immersive virtual environments. We have developed a new technology, the Virtual Glovebox (VGX), for simulation of experimental tasks that astronauts will perform aboard the Space Station. The VGX may also be used by crew support teams for design of experiments, testing equipment integration capability and optimizing the procedures astronauts will use. This is done through the 3D, desk-top sized, reach-in virtual environment that can simulate the microgravity environment in space. Additional features of the VGX allow for networking multiple users over the internet and operation of tele-robotic devices through an intuitive user interface. Although the system was developed for astronaut training and assisting support crews, Earth-bound applications, many emphasizing homeland security, have also been identified. Examples include training experts to handle hazardous biological and/or chemical agents in a safe simulation, operation of tele-robotic systems for assessing and diffusing threats such as bombs, and providing remote medical assistance to field personnel through a collaborative virtual environment. Thus, the emerging VGX simulation technology, while developed for space- based applications, can serve a dual use facilitating homeland security here on Earth.

  19. Modeling ramp compression experiments using large-scale molecular dynamics simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, Thomas Kjell Rene; Desjarlais, Michael Paul; Grest, Gary Stephen; Templeton, Jeremy Alan; Thompson, Aidan Patrick; Jones, Reese E.; Zimmerman, Jonathan A.; Baskes, Michael I. (University of California, San Diego); Winey, J. Michael (Washington State University); Gupta, Yogendra Mohan (Washington State University); Lane, J. Matthew D.; Ditmire, Todd (University of Texas at Austin); Quevedo, Hernan J. (University of Texas at Austin)

    2011-10-01

    Molecular dynamics simulation (MD) is an invaluable tool for studying problems sensitive to atomscale physics such as structural transitions, discontinuous interfaces, non-equilibrium dynamics, and elastic-plastic deformation. In order to apply this method to modeling of ramp-compression experiments, several challenges must be overcome: accuracy of interatomic potentials, length- and time-scales, and extraction of continuum quantities. We have completed a 3 year LDRD project with the goal of developing molecular dynamics simulation capabilities for modeling the response of materials to ramp compression. The techniques we have developed fall in to three categories (i) molecular dynamics methods (ii) interatomic potentials (iii) calculation of continuum variables. Highlights include the development of an accurate interatomic potential describing shock-melting of Beryllium, a scaling technique for modeling slow ramp compression experiments using fast ramp MD simulations, and a technique for extracting plastic strain from MD simulations. All of these methods have been implemented in Sandia's LAMMPS MD code, ensuring their widespread availability to dynamic materials research at Sandia and elsewhere.

  20. Atomistic simulations in Si processing: Bridging the gap between atoms and experiments

    International Nuclear Information System (INIS)

    Marques, Luis A.; Pelaz, Lourdes; Lopez, Pedro; Aboy, Maria; Santos, Ivan; Barbolla, Juan

    2005-01-01

    With devices shrinking to nanometric scale, process simulation tools have to shift from continuum models to an atomistic description of the material. However, the limited sizes and time scales accessible for detailed atomistic techniques usually lead to the difficult task of relating the information obtained from simulations to experimental data. The solution consists of the use of a hierarchical simulation scheme: more fundamental techniques are employed to extract parameters and models that are then feed into less detailed simulators which allow direct comparison with experiments. This scheme will be illustrated with the modeling of the amorphization and recrystallization of Si, which has been defined as a key challenge in the last edition of the International Technology Roadmap for Semiconductors. The model is based on the bond defect or IV pair, which is used as the building block of the amorphous phase. The properties of this defect have been studied using ab initio methods and classical molecular dynamics techniques. It is shown that the recombination of this defect depends on the surrounding bond defects, which accounts for the cooperative nature of the amorphization and recrystallization processes. The implementation of this model in a kinetic Monte Carlo code allows extracting data directly comparable with experiments. This approach provides physical insight on the amorphization and recrystallization mechanisms and a tool for the optimization of solid-phase epitaxial-related processes

  1. Portable parallel code for plasma simulations: Development experience and initial results

    International Nuclear Information System (INIS)

    Liewer, P.; Karmesin, S.R.; Brackbill, J.

    1994-01-01

    Plasma physics covers a wide variety of phenomena that are beyond the reach of symbolic mathematics, and for which experiments are often difficult. It is necessary to rely on computer experiments to test theories and understand the data. The authors describe progress in constructing a portable parallel Particle in Cell (PIC) code for three dimensional plasma simulations, and initial physics results using it for the Global Heliosphere problem. The code is designed to scale well to large parallel machines to take advantage of the fastest computers that are likely to be found in the foreseeable future. It is designed to allow the user to do a straight fluid (MHD) simulation, a kinetic PIC simulation to sample the velocity-space behavior of a system or a FLIP PIC simulation to model a low dissipation continuum fluid. It is designed to allow as much as possible of the algorithm to be written in dimension-independent style to allow the code to be used in 1, 2 or 3 dimensional systems. It is designed to be able to handle moderately complex geometries efficiently through the use of multiple patches, each of which is a deformable logically cartesian mesh. It is designed for several types of portability: to different numerics, physics, architectures, and people

  2. Video games, cinema, Bazin, and the myth of simulated lived experience

    Directory of Open Access Journals (Sweden)

    Mark J.P. Wolf

    2015-09-01

    Full Text Available Video games theory has advanced far enough that we can use it to reevaluate film theory as a  result, en route to broader, transmedial theorizing. This essay looks particularly at how video  games can be seen as participating in and advancing Andre Bazin’s “Myth of Total Cinema”, and  perhaps recontextualzing it as the Myth of Simulated Lived Experience.

  3. Random Ising model in three dimensions: theory, experiment and simulation - a difficult coexistence

    Directory of Open Access Journals (Sweden)

    B.Berche

    2005-01-01

    Full Text Available We discuss different approaches to the study of the effect of disorder in the three-dimensional Ising model. From the theoretical point of view, renormalization group calculations provide quite accurate results. Experiments carried out on crystalline mixtures of compounds lead to measurements as accurate as three digits on the values of critical exponents. Numerically, extensive Monte Carlo simulations then pretend to be of comparable accuracy. Life becomes complicated when details are compared between the three approaches.

  4. Understanding Creep Mechanisms in Graphite with Experiments, Multiscale Simulations, and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Eapen, Jacob [North Carolina State Univ., Raleigh, NC (United States); Murty, Korukonda [North Carolina State Univ., Raleigh, NC (United States); Burchell, Timothy [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-06-02

    Disordering mechanisms in graphite have a long history with conflicting viewpoints. Using Raman and x-ray photon spectroscopy, electron microscopy, x-ray diffraction experiments and atomistic modeling and simulations, the current project has developed a fundamental understanding of early-to-late state radiation damage mechanisms in nuclear reactor grade graphite (NBG-18 and PCEA). We show that the topological defects in graphite play an important role under neutron and ion irradiation.

  5. Design of simulated nuclear electronics laboratory experiments based on IAEA-TECDOC-530 on pcs

    International Nuclear Information System (INIS)

    Ghousia, S.F.; Nadeem, M.; Khaleeq, M.T.

    2002-05-01

    In this IAEA project, PK-11089 (Design of Simulated Nuclear Electronics Laboratory Experiments based on IAEA-TECDOC-530 on PCs), a software package consisting of Computer-Simulated Laboratory Experiments on Nuclear Electronics compatible with the IAEA-TECDOC-530 (Nuclear Electronics Laboratory Manual) has been developed in OrCAD 9.0 (an electronic circuit simulation software environment) as a self-training aid. The software process model employed in this project is the Feedback Waterfall model with some Rapid Application Model. The project work is completed in the five phases of the SDLC, (all of them have been fully completed) which includes the Requirement Definition, Phase, System and Software Design, Implementation and Unit testing, Integration and System-testing phase and the Operation and Maintenance phase. A total of 125 circuits are designed in 39 experiments from Power Supplies, Analog circuits, Digital circuits and Multi-channel analyzer sections. There is another set of schematic designs present in the package, which contains faulty circuits. This set is designed for the learners to exercise the troubleshooting. The integration and system-testing phase was carried out simultaneously. The Operation and Maintenance phase has been implemented by accomplishing it through some trainees and some undergraduate engineering students by allowing them to play with the software independently. (author)

  6. Simulation of hydrogen deflagration experiment – Benchmark exercise with lumped-parameter codes

    International Nuclear Information System (INIS)

    Kljenak, Ivo; Kuznetsov, Mikhail; Kostka, Pal; Kubišova, Lubica; Maltsev, Mikhail; Manzini, Giovanni; Povilaitis, Mantas

    2015-01-01

    Highlights: • Blind and open simulations of hydrogen combustion experiment in large-scale containment-like facility with different lumped-parameter codes. • Simulation of axial as well as radial flame propagation. • Confirmation of adequacy of lumped-parameter codes for safety analyses of actual nuclear power plants. - Abstract: An experiment on hydrogen deflagration (Upward Flame Propagation Experiment – UFPE) was proposed by the Jozef Stefan Institute (Slovenia) and performed in the HYKA A2 facility at the Karlsruhe Institute of Technology (Germany). The experimental results were used to organize a benchmark exercise for lumped-parameter codes. Six organizations (JSI, AEP, LEI, NUBIKI, RSE and UJD SR) participated in the benchmark exercise, using altogether four different computer codes: ANGAR, ASTEC, COCOSYS and ECART. Both blind and open simulations were performed. In general, all the codes provided satisfactory results of the pressure increase, whereas the results of the temperature show a wider dispersal. Concerning the flame axial and radial velocities, the results may be considered satisfactory, given the inherent simplification of the lumped-parameter description compared to the local instantaneous description

  7. Detailed high-resolution three-dimensional simulations of OMEGA separated reactants inertial confinement fusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Haines, Brian M., E-mail: bmhaines@lanl.gov; Fincke, James R.; Shah, Rahul C.; Boswell, Melissa; Fowler, Malcolm M.; Gore, Robert A.; Hayes-Sterbenz, Anna C.; Jungman, Gerard; Klein, Andreas; Rundberg, Robert S.; Steinkamp, Michael J.; Wilhelmy, Jerry B. [Los Alamos National Laboratory, MS T087, Los Alamos, New Mexico 87545 (United States); Grim, Gary P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Forrest, Chad J.; Silverstein, Kevin; Marshall, Frederic J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2016-07-15

    We present results from the comparison of high-resolution three-dimensional (3D) simulations with data from the implosions of inertial confinement fusion capsules with separated reactants performed on the OMEGA laser facility. Each capsule, referred to as a “CD Mixcap,” is filled with tritium and has a polystyrene (CH) shell with a deuterated polystyrene (CD) layer whose burial depth is varied. In these implosions, fusion reactions between deuterium and tritium ions can occur only in the presence of atomic mix between the gas fill and shell material. The simulations feature accurate models for all known experimental asymmetries and do not employ any adjustable parameters to improve agreement with experimental data. Simulations are performed with the RAGE radiation-hydrodynamics code using an Implicit Large Eddy Simulation (ILES) strategy for the hydrodynamics. We obtain good agreement with the experimental data, including the DT/TT neutron yield ratios used to diagnose mix, for all burial depths of the deuterated shell layer. Additionally, simulations demonstrate good agreement with converged simulations employing explicit models for plasma diffusion and viscosity, suggesting that the implicit sub-grid model used in ILES is sufficient to model these processes in these experiments. In our simulations, mixing is driven by short-wavelength asymmetries and longer-wavelength features are responsible for developing flows that transport mixed material towards the center of the hot spot. Mix material transported by this process is responsible for most of the mix (DT) yield even for the capsule with a CD layer adjacent to the tritium fuel. Consistent with our previous results, mix does not play a significant role in TT neutron yield degradation; instead, this is dominated by the displacement of fuel from the center of the implosion due to the development of turbulent instabilities seeded by long-wavelength asymmetries. Through these processes, the long

  8. Improving dental experiences by using virtual reality distraction: a simulation study.

    Science.gov (United States)

    Tanja-Dijkstra, Karin; Pahl, Sabine; White, Mathew P; Andrade, Jackie; Qian, Cheng; Bruce, Malcolm; May, Jon; Moles, David R

    2014-01-01

    Dental anxiety creates significant problems for both patients and the dental profession. Some distraction interventions are already used by healthcare professionals to help patients cope with unpleasant procedures. The present study is novel because it a) builds on evidence that natural scenery is beneficial for patients, and b) uses a Virtual Reality (VR) representation of nature to distract participants. Extending previous work that has investigated pain and anxiety during treatment, c) we also consider the longer term effects in terms of more positive memories of the treatment, building on a cognitive theory of memory (Elaborated Intrusions). Participants (n = 69) took part in a simulated dental experience and were randomly assigned to one of three VR conditions (active vs. passive vs. control). In addition, participants were distinguished into high and low dentally anxious according to a median split resulting in a 3×2 between-subjects design. VR distraction in a simulated dental context affected memories a week later. The VR distraction had effects not only on concurrent experiences, such as perceived control, but longitudinally upon the vividness of memories after the dental experience had ended. Participants with higher dental anxiety (for whom the dental procedures were presumably more aversive) showed a greater reduction in memory vividness than lower dental-anxiety participants. This study thus suggests that VR distractions can be considered as a relevant intervention for cycles of care in which people's previous experiences affect their behaviour for future events.

  9. Improving dental experiences by using virtual reality distraction: a simulation study.

    Directory of Open Access Journals (Sweden)

    Karin Tanja-Dijkstra

    Full Text Available Dental anxiety creates significant problems for both patients and the dental profession. Some distraction interventions are already used by healthcare professionals to help patients cope with unpleasant procedures. The present study is novel because it a builds on evidence that natural scenery is beneficial for patients, and b uses a Virtual Reality (VR representation of nature to distract participants. Extending previous work that has investigated pain and anxiety during treatment, c we also consider the longer term effects in terms of more positive memories of the treatment, building on a cognitive theory of memory (Elaborated Intrusions. Participants (n = 69 took part in a simulated dental experience and were randomly assigned to one of three VR conditions (active vs. passive vs. control. In addition, participants were distinguished into high and low dentally anxious according to a median split resulting in a 3×2 between-subjects design. VR distraction in a simulated dental context affected memories a week later. The VR distraction had effects not only on concurrent experiences, such as perceived control, but longitudinally upon the vividness of memories after the dental experience had ended. Participants with higher dental anxiety (for whom the dental procedures were presumably more aversive showed a greater reduction in memory vividness than lower dental-anxiety participants. This study thus suggests that VR distractions can be considered as a relevant intervention for cycles of care in which people's previous experiences affect their behaviour for future events.

  10. Ion-nanostructure interaction. Comparing simulation and experiment towards surface structuring using nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Holland-Moritz, Henry

    2016-10-18

    Nanotechnology is a buzzword in context of the proceeding miniaturization of devices and their components. Nanoparticles (NPs) can nowadays easily be synthesized from different material compositions by different chemical and physical processes. However, most of these techniques work close to or at the thermal equilibrium. One subsequent approach to tune materials beyond equilibrium conditions is ion beam irradiation. An important effect of this approach is sputtering. Sputtering is enhanced in NPs compared to their bulk counterparts due to their large surface-to-volume ratio, especially when the ion range matches the NP size. In this work, the sputtering effects of Ar{sup +} and Ga{sup +} ion irradiated Au nanoparticles are investigated in detail by Monte Carlo (MC) and molecular dynamics (MD) simulations and a variety of experiments. The sputtering of Ar{sup +} and Ga{sup +} irradiated Au NPs was investigated as a function of ion energy, NP size and impact parameter by the MC code iradina and MD code parcas. The simulation results are directly compared to experiments using high resolution scanning electron microscopy (SEM) of Au NPs on top of Si, whereat the sputter yields are significantly enhanced compared to the MC simulations. Additionally, the interaction of NPs and substrate were investigated by Rutherford backscatter spectrometry (RBS), atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). A new MC code was developed to study the redeposition of sputtered atoms of Ga{sup +} irradiated Au NP arrays on neighboring NPs. The redeposition can lead to growth of NPs with diameters of 1 nm in vicinity of ∝50 nm NP. These simulations are directly compared to an in situ experiment. Nanostructures, spherical NPs as well as nanowires (NWs) are used as irradiation masks to structure lithium niobate (LNO) using the ion beam enhanced etching (IBEE) technique. The aspect ratio of the obtained structures can be enhanced by a second IBEE step

  11. Gradient simulation experiments for targeting population heterogeneity in continuous Saccharomyces cerevisiae fermentation

    DEFF Research Database (Denmark)

    Heins, Anna-Lena; Lencastre Fernandes, Rita; Lundin, L.

    of population heterogeneity, a Saccharomyces cerevisiae growth reporter strain based on the expression of green fluorescent protein (GFP) was constructed which allows to perform single cell analysis, and thereby created the possibility to map population heterogeneity. A factorial design experiment of the growth...... experience rapid changes in environmental conditions as they circulate throughout the reactor, which might pose stress on the cells, affect their metabolism and consequently affect the level of heterogeneity of the population. To further investigate these phenomena and gain a deeper understanding...... of the growth rate reporter strain was performed and the physiological changes were analysed on a single cell level. From the simulation experiment it could be demonstrated that glucose had a clear influence on subpopulation distribution....

  12. SAS4A simulation of the OPERA-15 two-dimensional voiding experiment

    International Nuclear Information System (INIS)

    Briggs, L.L.

    1984-01-01

    A major effort is currently being pursued to validate the SAS4A LMFBR accident analysis code. Part of this effort involves SAS4A analysis of both in-pile and out-of-pile safety experiments. Such an experiment is the fifteen-pin Out-of-Pile Explusion and Reentry Apparatus (OPERA) test run at Argonne National Laboratory. This test uses a fifteen-pin triangular-shaped bundle of simulant fuel pins to demonstrate two-dimensional voiding behavior in a LMFBR subassembly during a Loss-of-Flow (LOF) accident. This experiment was chosen for SAS4A analysis both for its value in code validation and its usefulness in evaluating the limitations of the one-dimensional SAS4A sodium voiding model in accident analysis

  13. Enhancing Human Responses to Climate Change Risks through Simulated Flooding Experiences

    Science.gov (United States)

    Zaalberg, Ruud; Midden, Cees

    Delta areas are threatened by global climate change. The general aims of our research were (1) to increase our understanding of climate and flood risk perceptions and the factors that influence these judgments, and (2) to seek for interventions that can contribute to a realistic assessment by laypersons of long-term flooding risks. We argue that awareness of one's own vulnerability to future flooding and insights into the effectiveness of coping strategies is driven by direct flooding experiences. In the current research multimodal sensory stimulation by means of interactive 3D technology is used to simulate direct flooding experiences at the experiential or sensory level, thereby going beyond traditional persuasion attempts using fear-evoking images. Our results suggest that future communication efforts should not only use these new technologies to transfer knowledge about effective coping strategies and flooding risks, but should especially be directed towards residents living in flood prone areas, but who lack direct flooding experiences as their guiding principle.

  14. Laboratory simulation of the formation of an ionospheric depletion using Keda Space Plasma EXperiment (KSPEX

    Directory of Open Access Journals (Sweden)

    Pengcheng Yu

    2017-10-01

    Full Text Available In the work, the formation of an ionospheric depletion was simulated in a controlled laboratory plasma. The experiment was performed by releasing chemical substance sulfur hexafluoride (SF6 into the pure argon discharge plasma. Results indicate that the plasma parameters change significantly after release of chemicals. The electron density is nearly depleted due to the sulfur hexafluoride-electron attachment reaction; and the electron temperature and space potential experience an increase due to the decrease of the electron density. Compared to the traditional active release experiments, the laboratory scheme can be more efficient, high repetition rate and simpler measurement of the varying plasma parameter after chemical releasing. Therefore, it can effective building the bridge between the theoretical work and real space observation.

  15. High-fidelity simulation and legal/ethical concepts: a transformational learning experience.

    Science.gov (United States)

    Smith, Katharine V; Witt, Jacki; Klaassen, Joann; Zimmerman, Christine; Cheng, An-Lin

    2012-05-01

    Students in an undergraduate legal and ethical issues course continually told the authors that they did not have time to study for the course because they were busy studying for their clinical courses. Faculty became concerned that students were failing to realize the value of legal and ethical concepts as applicable to clinical practice. This led the authors to implement a transformational learning experience in which students applied legal and ethical course content in a high-fidelity human simulation (HFHS) scenario. A preliminary evaluation compared the new HFHS experience with in-person and online student groups using the same case. Based on both student and faculty perceptions, the HFHS was identified as the best of the three approaches for providing a transformational learning experience regarding legal and ethical content.

  16. Simulations

    CERN Document Server

    Ngada, Narcisse

    2015-06-15

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  17. Experiments and simulations on the incompressible, Rayleigh-Taylor instability with small wavelength initial perturbations

    Science.gov (United States)

    Roberts, Michael Scott

    The Rayleigh-Taylor instability is a buoyancy driven instability that takes place in a stratified fluid system with a constant acceleration directed from the heavy fluid into the light fluid. In this study, both experimental data and numerical simulations are presented. Experiments are performed primarily using a lithium-tungstate aqueous solution as the heavy liquid, but sometimes a calcium nitrate aqueous solution is used for comparison purposes. Experimental data is obtained for both miscible and immiscible fluid combinations. For the miscible experiments the light liquid is either ethanol or isopropanol, and for the immiscible experiments either silicone oil or trans-anethole is used. The resulting Atwood number is either 0.5 when the lithium-tungstate solution is used or 0.2 when the calcium nitrate solution is used. These fluid combinations are either forced or left unforced. The forced experiments have an initial perturbation imposed by vertically oscillating the liquid containing tank to produce Faraday waves at the interface. The unforced experiments rely on random interfacial fluctuations, due to background noise, to seed the instability. The liquid combination is partially enclosed in a test section that is accelerated downward along a vertical rail system causing the Rayleigh-Taylor instability. Accelerations of approximately 1g (with a weight and pulley system) or 10g (with a linear induction motor system) are experienced by the liquids. The tank is backlit and digitally recorded with high speed video cameras. These experiments are then simulated with the incompressible, Navier-Stokes code Miranda. The main focus of this study is the growth parameter (α) of the mixing region produced by the instability after it has become apparently self-similar and turbulent. The measured growth parameters are compared to determine the effects of miscibility and initial perturbations (of the small wavelength, finite bandwidth type used here). It is found that while

  18. Modeling and Depletion Simulations for a High Flux Isotope Reactor Cycle with a Representative Experiment Loading

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Betzler, Ben [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Hirtz, Gregory John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Sunny, Eva [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division

    2016-09-01

    The purpose of this report is to document a high-fidelity VESTA/MCNP High Flux Isotope Reactor (HFIR) core model that features a new, representative experiment loading. This model, which represents the current, high-enriched uranium fuel core, will serve as a reference for low-enriched uranium conversion studies, safety-basis calculations, and other research activities. A new experiment loading model was developed to better represent current, typical experiment loadings, in comparison to the experiment loading included in the model for Cycle 400 (operated in 2004). The new experiment loading model for the flux trap target region includes full length 252Cf production targets, 75Se production capsules, 63Ni production capsules, a 188W production capsule, and various materials irradiation targets. Fully loaded 238Pu production targets are modeled in eleven vertical experiment facilities located in the beryllium reflector. Other changes compared to the Cycle 400 model are the high-fidelity modeling of the fuel element side plates and the material composition of the control elements. Results obtained from the depletion simulations with the new model are presented, with a focus on time-dependent isotopic composition of irradiated fuel and single cycle isotope production metrics.

  19. Comparison of Muon Arrival Time Distributions measured in KASCADE Experiment with Monte Carlo Simulations

    International Nuclear Information System (INIS)

    Badea, A.F.; Brancus, I.M.; Haeusler, R.; Rebel, H.

    2000-01-01

    The muon arrival time distributions of Extensive Air Showers (EAS) have been studied in KASCADE experiment by data collected in the period October 1997 - April 1999 with more than 3.4 millions of reconstructed showers. The radial distance of the shower center from the central detector has been selected smaller than 110 m. The experimental muon arrival time distributions are compared with simulations of the air shower development, calculated with the Monte Carlo air shower simulation program CORSIKA. The actual calculations are based on the QGSJET model and cover an energy range of 5·10 14 - 3.06·10 16 eV (divided in 7 overlapping energy bins) and a zenith angle range of 0 angle - 40 angle. They are performed for three mass groups: H = light group, O = CNO group, Fe = heavy group) with an energy distribution of a spectral index of -2.7. The simulations comprise a set of ≅ 2000$ showers for each case, except for the bins of the highest energies (6.51·10 15 - 1.82·10 16 eV with ≅1000$ simulated showers and 1.09·10 16 - 3.06·10 16 eV with ≅ 500 simulated showers). The response of the KASCADE detector system and the timing qualities have been simulated using the CRES program, dedicatedly developed by the KASCADE group on the basis of the GEANT code. The particles of the simulated EAS are tracked through the detector setup and the timing response of the detectors are recorded for various core distances from the central detector facilities. Particularly, it should be noted that the timing depends on the energy deposit in the scintillation detectors and on the multiplicities of the muon samples spanning the arrival time distributions of the single EAS. Such effects slightly distorts the measured time distributions and have been corrected by introducing a corresponding correction procedure. The dependence of the experimental and simulated median time values on the N μ tr range, as being proportional to the primary energy, is presented. The good agreement of the

  20. Studies of scintillator optical properties, electronics simulation and data analysis for the BOREXINO neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lewke, Timo

    2013-10-18

    Borexino is a state-of-the-art low-energy neutrino detector. Many results, like the first real-time measurement of {sup 7}Be neutrinos and the detection of pep neutrinos, could be reported. However, still some parts of the solar neutrino spectrum remain unseen. With a better detector understanding and monitoring these unexploited regions could be investigated. The results achieved in course of the present thesis account for accomplishing these improvements. First, the ionization quenching for electrons in liquid scintillators is investigated using a specially designed and build experiment. This effect is especially interesting for low-energy events and, therefore, has a direct influence on the possibility to detect CNO and pp neutrinos. With a coincidence circuit and the properties of Compton scattering the quenching is analysed. Further, the so-called Birks factor kB is measured for the scintillator used in the running Borexino experiment. As the Birks factor is also an important input parameter to simulations of the future large scale neutrino experiment LENA, the Birks factor of LENA's most probable scintillator is determined as well. Second, as muons are responsible for a large amount of background, an excellent working muon veto is essential. During this thesis, it was achieved to monitor the muon tagging stability and efficiency for a long period of time. Further, to verify the muon track reconstruction Monte Carlo simulations are needed. For the Inner Detector of Borexino the simulation is fully operable. In course of this thesis the complete electronics system of the Outer Detector is included into the simulation tool. In this way, a functioning simulation mimicking real physical events is generated. In addition, the output of the simulation can now be accessed and evaluated by the normal data handling system of Borexino. A comparison to real data and, therefore, validating the muon track reconstruction is now possible. Last, to check the neutron

  1. Studies of scintillator optical properties, electronics simulation and data analysis for the BOREXINO neutrino experiment

    International Nuclear Information System (INIS)

    Lewke, Timo

    2013-01-01

    Borexino is a state-of-the-art low-energy neutrino detector. Many results, like the first real-time measurement of 7 Be neutrinos and the detection of pep neutrinos, could be reported. However, still some parts of the solar neutrino spectrum remain unseen. With a better detector understanding and monitoring these unexploited regions could be investigated. The results achieved in course of the present thesis account for accomplishing these improvements. First, the ionization quenching for electrons in liquid scintillators is investigated using a specially designed and build experiment. This effect is especially interesting for low-energy events and, therefore, has a direct influence on the possibility to detect CNO and pp neutrinos. With a coincidence circuit and the properties of Compton scattering the quenching is analysed. Further, the so-called Birks factor kB is measured for the scintillator used in the running Borexino experiment. As the Birks factor is also an important input parameter to simulations of the future large scale neutrino experiment LENA, the Birks factor of LENA's most probable scintillator is determined as well. Second, as muons are responsible for a large amount of background, an excellent working muon veto is essential. During this thesis, it was achieved to monitor the muon tagging stability and efficiency for a long period of time. Further, to verify the muon track reconstruction Monte Carlo simulations are needed. For the Inner Detector of Borexino the simulation is fully operable. In course of this thesis the complete electronics system of the Outer Detector is included into the simulation tool. In this way, a functioning simulation mimicking real physical events is generated. In addition, the output of the simulation can now be accessed and evaluated by the normal data handling system of Borexino. A comparison to real data and, therefore, validating the muon track reconstruction is now possible. Last, to check the neutron tagging, CNGS

  2. Theoretical Simulations and Ultrafast Pump-probe Spectroscopy Experiments in Pigment-protein Photosynthetic Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Buck, D. R. [Iowa State Univ., Ames, IA (United States)

    2000-09-12

    Theoretical simulations and ultrafast pump-probe laser spectroscopy experiments were used to study photosynthetic pigment-protein complexes and antennae found in green sulfur bacteria such as Prosthecochloris aestuarii, Chloroflexus aurantiacus, and Chlorobium tepidum. The work focused on understanding structure-function relationships in energy transfer processes in these complexes through experiments and trying to model that data as we tested our theoretical assumptions with calculations. Theoretical exciton calculations on tubular pigment aggregates yield electronic absorption spectra that are superimpositions of linear J-aggregate spectra. The electronic spectroscopy of BChl c/d/e antennae in light harvesting chlorosomes from Chloroflexus aurantiacus differs considerably from J-aggregate spectra. Strong symmetry breaking is needed if we hope to simulate the absorption spectra of the BChl c antenna. The theory for simulating absorption difference spectra in strongly coupled photosynthetic antenna is described, first for a relatively simple heterodimer, then for the general N-pigment system. The theory is applied to the Fenna-Matthews-Olson (FMO) BChl a protein trimers from Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from Chlorobium tepidum. Circular dichroism spectra of the FMO trimer are unusually sensitive to diagonal energy disorder. Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Anisotropic absorption difference spectroscopy measurements are less consistent with 21-pigment trimer simulations than 7-pigment monomer simulations which assume that the laser-prepared states are localized within a subunit of the trimer. Experimental anisotropies from real samples likely arise from statistical averaging over states with diagonal energies shifted by

  3. Integration of genetic algorithm, computer simulation and design of experiments for forecasting electrical energy consumption

    International Nuclear Information System (INIS)

    Azadeh, A.; Tarverdian, S.

    2007-01-01

    This study presents an integrated algorithm for forecasting monthly electrical energy consumption based on genetic algorithm (GA), computer simulation and design of experiments using stochastic procedures. First, time-series model is developed as a benchmark for GA and simulation. Computer simulation is developed to generate random variables for monthly electricity consumption. This is achieved to foresee the effects of probabilistic distribution on monthly electricity consumption. The GA and simulated-based GA models are then developed by the selected time-series model. Therefore, there are four treatments to be considered in analysis of variance (ANOVA) which are actual data, time series, GA and simulated-based GA. Furthermore, ANOVA is used to test the null hypothesis of the above four alternatives being equal. If the null hypothesis is accepted, then the lowest mean absolute percentage error (MAPE) value is used to select the best model, otherwise the Duncan Multiple Range Test (DMRT) method of paired comparison is used to select the optimum model, which could be time series, GA or simulated-based GA. In case of ties the lowest MAPE value is considered as the benchmark. The integrated algorithm has several unique features. First, it is flexible and identifies the best model based on the results of ANOVA and MAPE, whereas previous studies consider the best-fit GA model based on MAPE or relative error results. Second, the proposed algorithm may identify conventional time series as the best model for future electricity consumption forecasting because of its dynamic structure, whereas previous studies assume that GA always provide the best solutions and estimation. To show the applicability and superiority of the proposed algorithm, the monthly electricity consumption in Iran from March 1994 to February 2005 (131 months) is used and applied to the proposed algorithm

  4. Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-15

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  5. Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte-Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Ledieu, A

    2004-10-01

    This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

  6. Self-assembly of "Mickey Mouse" shaped colloids into tube-like structures: experiments and simulations.

    Science.gov (United States)

    Wolters, Joost R; Avvisati, Guido; Hagemans, Fabian; Vissers, Teun; Kraft, Daniela J; Dijkstra, Marjolein; Kegel, Willem K

    2015-02-14

    The self-assembly of anisotropic patchy particles with a triangular shape was studied by experiments and computer simulations. The colloidal particles were synthesized in a two-step seeded emulsion polymerization process, and consist of a central smooth lobe connected to two rough lobes at an angle of ∼90°, resembling the shape of a "Mickey Mouse" head. Due to the difference in overlap volume, adding an appropriate depletant induces an attractive interaction between the smooth lobes of the colloids only, while the two rough lobes act as steric constraints. The essentially planar geometry of the Mickey Mouse particles is a first geometric deviation of dumbbell shaped patchy particles. This new geometry enables the formation of one-dimensional tube-like structures rather than spherical, essentially zero-dimensional micelles. At sufficiently strong attractions, we indeed find tube-like structures with the sticky lobes at the core and the non-sticky lobes pointing out as steric constraints that limit the growth to one direction, providing the tubes with a well-defined diameter but variable length both in experiments and simulations. In the simulations, we found that the internal structure of the tubular fragments could either be straight or twisted into so-called Bernal spirals.

  7. Simulations of hydrogen distribution experiments using the PRESCON2 and GOTHIC codes

    International Nuclear Information System (INIS)

    Nguyen, T.H.; Collins, W.M.

    1994-01-01

    The main objective of this work is to develop modelling guidelines in the use of containment models to more accurately predict hydrogen distribution in the HDR facility and to assess the ability of both lumped and distributed parameter models in predicting natural convective flows within containment. Experiences learned from this exercise will be applied to present methodologies used in licensing analyses for CANDU containments. PRESCON2 simulations of hydrogen distribution experiments performed in the HDR facility show hydrogen and helium concentrations are under-predicted at high elevations and over predicted at low elevations. Acceptable predictions of the gas concentration are obtained in the vicinity of the release. Results obtained from GOTHIC simulations using lumped parameter models are very comparable to those predicted by PRESCON2. This indicates that lumped parameter codes tend to over-estimate the degree of mixing of fluids due to the inherent nodal atmospheric homogeneity assumption in their numerical formulation. Results obtained from the GOTHIC simulation using a simple distributed parameter model show little improvement compared to those predicted using the lumped parameter model. This indicates that a simple 3-D model will not be sufficient to make significant improvements in the results. More detailed modelling of the junction flows and finer grids should lead to more accurate results. More detailed investigations employing finer 3-D meshes is under investigation. (author)

  8. Two-Plasmon Decay: Simulations and Experiments on the NIKE Laser System

    Science.gov (United States)

    Phillips, Lee; Weaver, J. L.; Oh, J.; Schmitt, A. J.; Obenschain, S.; Colombant, D.

    2009-11-01

    NIKE is a Krf laser system at the Naval Research Laboratory used to explore hydrodynamic stability, equation of state, and other issues arising in the research toward inertial fusion energy. The relatively small KrF wavelength, according to widely used theories, raises the threshold of most parametric instabilities. We report on simulations performed using the FAST3d radiation hydrocode to design TPD experiments. By post-processing the results of the simulations we have designed experiments that have explored the use of simple threshold formulas (from developing theories) and help establish the soundness of our simulational approach. Turning to the targets proposed for ICF energy research, we have found that among the designs for the proposed Fusion Test Facility (Obenschain et al., Phys. Plasmas 13 056320 (2006)), are some that are below LPI thresholds. We have also studied high-gain KrF shock ignition designs and found that they are below LPI thresholds for most of the implosion, becoming susceptible to TPD only late in the pulse.

  9. Investigation on novel raceway pond with inclined paddle wheels through simulation and microalgae culture experiments.

    Science.gov (United States)

    Zeng, Fanxue; Huang, Jianke; Meng, Chen; Zhu, Fachao; Chen, Jianpei; Li, Yuanguang

    2016-01-01

    The open raceway ponds are nowadays the most used large-scale reactors for microalgae culture. To avoid the stacking of microalgae, the paddle wheels are the most widely used to circulate and mix the culture medium. In this paper, a numerical simulation using computational fluid dynamics (CFD) was used to investigate the hydrodynamic characteristics of open raceway ponds with different types of paddle wheels (the traditional paddle wheels and the novel paddle wheels with specially inclined angle of the blades). The particle image velocimetry (PIV) was used to validate the reliability of the CFD model. The CFD simulation results showed that the novel raceway pond with 15° inclined angle of the blades had the best mixing efficiency under the same power consumption. Lastly, the results of microalgae culture experiments showed that the growth rates of Chlorella pyrenoidosa in the novel raceway pond with 15° inclined angle of the blades were higher than those in the traditional reactor. The results of the culture experiments and CFD simulations were identical with each other. Therefore, a novel paddle wheel with 15° inclined angle of the blades was obtained for better microalgae cultivation.

  10. Experience with simulation education at the University of the Third Age at JFM CU in Martin

    Directory of Open Access Journals (Sweden)

    Mária Zanovitová

    2016-07-01

    Full Text Available Background: Considering current demographic trends in society, education of seniors has become real needs and a challenge for the field of education and training institutions. Universities of the Third Age (UTA represent one option for senior education allowing them to study various fields at university level. Within UTA studies, the seniors are interested in studying mainly the issues of health and disease, aging and the social and legal issues. Seniors represent a group of students with specific educational needs. In teaching them it is therefore important to choose teaching methods that take account of developmental changes of the period, contain elements of clearness, and provide the space for communication and activity with the use of previous experiences of seniors. In the framework of elderly education at the UTA at Jessenius Faculty of Medicine in Martin (JFM CU the simulation methods are also used that bring elements of clarity and attractiveness into the teaching and serve to bridge theoretical education and practical training. Objective: The aim of the study was to determine the UTA senior students’ views on the use of simulation models and simulations in education and to find out what is their satisfaction with the training in the Simulation Center at JFM CU in Martin. Methods: Questionnaire of own construction was used to gather empirical data. The study involved 30 senior students of the third year of studies in the program “Elderly Care”, out of which 25 were women and 5 men. The average age of respondents was 67.3 years (SD 5.6. Results: Within education and training in Simulation Center, the seniors most positively evaluated preparedness, presentation and interpretation of the lecturer (4.96 and the way in which information were administered (4.76. They had the opportunity of hands-on work with the simulation models and practical training of their skills and such experience was evaluated as excellent (4.70. Seniors also

  11. Hybrid simulation of toroidal Alfvén eigenmode on the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D., E-mail: deyongl@uci.edu [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Fu, G. Y.; Podestà, M.; Breslau, J. A.; Fredrickson, E. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Crocker, N. A.; Kubota, S. [Department of Physics and Astronomy, University of California, Los Angles, California 90095 (United States)

    2015-04-15

    Energetic particle modes and Alfvén eigenmodes driven by super-Alfvénic fast ions are routinely observed in neutral beam heated plasmas on the National Spherical Torus eXperiment (NSTX). These modes can significantly impact fast ion transport and thus cause fast ion redistribution or loss. Self-consistent linear simulations of Toroidal Alfvén Eigenmodes (TAEs) in NSTX plasmas have been carried out with the kinetic/magnetohydrodynamic hybrid code M3D-K using experimental plasma parameters and profiles including plasma toroidal rotation. The simulations show that unstable TAEs with n=3,4, or 5 can be excited by the fast ions from neutral beam injection. The simulated mode frequency, mode radial structure, and phase shift are consistent with measurements from a multi-channel microwave reflectometer diagnostic. A sensitivity study on plasma toroidal rotation, safety factor q profile, and initial fast ion distribution is performed. The simulations show that rotation can have a significant destabilizing effect when the rotation is comparable or larger than the experimental level. The mode growth rate is sensitive to q profile and fast ion distribution. Although mode structure and peak position depend somewhat on q profile and plasma rotation, the variation of synthetic reflectometer response is within experimental uncertainty and it is not sensitive enough to see the difference clearly.

  12. Exploring the Dynamics of Cell Processes through Simulations of Fluorescence Microscopy Experiments

    Science.gov (United States)

    Angiolini, Juan; Plachta, Nicolas; Mocskos, Esteban; Levi, Valeria

    2015-01-01

    Fluorescence correlation spectroscopy (FCS) methods are powerful tools for unveiling the dynamical organization of cells. For simple cases, such as molecules passively moving in a homogeneous media, FCS analysis yields analytical functions that can be fitted to the experimental data to recover the phenomenological rate parameters. Unfortunately, many dynamical processes in cells do not follow these simple models, and in many instances it is not possible to obtain an analytical function through a theoretical analysis of a more complex model. In such cases, experimental analysis can be combined with Monte Carlo simulations to aid in interpretation of the data. In response to this need, we developed a method called FERNET (Fluorescence Emission Recipes and Numerical routines Toolkit) based on Monte Carlo simulations and the MCell-Blender platform, which was designed to treat the reaction-diffusion problem under realistic scenarios. This method enables us to set complex geometries of the simulation space, distribute molecules among different compartments, and define interspecies reactions with selected kinetic constants, diffusion coefficients, and species brightness. We apply this method to simulate single- and multiple-point FCS, photon-counting histogram analysis, raster image correlation spectroscopy, and two-color fluorescence cross-correlation spectroscopy. We believe that this new program could be very useful for predicting and understanding the output of fluorescence microscopy experiments. PMID:26039162

  13. Events simulation production for the BaBar experiment using the grid approach content

    International Nuclear Information System (INIS)

    Fella, A.; Andreotti, D.; Luppi, E.

    2007-01-01

    The BaBar experiment is taking data since 1999, investigating the violation of charge and parity (CP) symmetry in the field of High Energy Physics. Event simulation is an intensive computing task, due to the complexity of algorithm based on Monte-Carlo method implemented using the GEANT engine. Data needed as input for the simulation, stored in the ROOT format, are classified into two categories: conditions data for describing the detector status when data are recorded, and background triggers data for including noise signal necessary to obtain a realistic simulation. In order to satisfy these requirements, in the traditional BaBar computing model events are distributed over several sites involved in the collaboration where each site manager centrally manages a private farm dedicated to simulation production. The new grid approach applied to the BaBar production framework is discussed along with the schema adopted for data deployment via Xrootd servers, including data management using grid middle ware on distributed storage facilities spread over the INFN-GRID network. A comparison between the two models is provided, describing also the custom application developed for performing the whole production task on the grid and showing results achieved. (Author)

  14. The effects of computer assisted physics experiment simulations on students' learning

    Directory of Open Access Journals (Sweden)

    Turhan Civelek

    2013-11-01

    Full Text Available The main goal of this study is to present the significant difference between utilization of simulations of physics experiment during lectures and traditional physics lecture. Two groups of 115 students were selected for the purpose of the study. The same subjects have been taught to both groups, while a group of 115 had their lectures in science and technology class supported by physics experiment simulations for a month, the other group of115 had their lectures ina traditional way. The research has been conducted in Izzet Unver highs school in Istanbul, Gungoren. The main resource of this research is the data collected through surveys. The survey is a result of the literature and the suggestions of the experts on the topic. Thirty questions were prepared under ten topics. Two different surveys were conducted during the data collection. While the first survey questions focused on the effects of traditional lecturing on students, the second survey questions were targeting the effects of lecturing via the support of psychics experiment simulations. The data collected as a result of the survey which was coded in to SPSS Software and statistical anal yses was conducted. In order to test the significant difference between the means t-test was utilized. 0.05 was chosen as the significance level. As a result of the analyses utilized, significant differences were found in their satisfaction on class materials, in their motivation, in their learning speed, in their interest in the class, and in their contribution to the class. In findings such as the effect on students’ learning, information availability, organization of information, students’ integration to the class and gaining different point of views “lectures supported by physics experiment simulations” is significantly different from traditional lecturing. As the result of the literature review and the statistical analyses, “lectures supported via physics experiment simulations” seem to

  15. Simulation of the Phebus FPT1 experiment; Simulacion del experimento Phebus FPT1

    Energy Technology Data Exchange (ETDEWEB)

    Amador G, R.; Nunez C, A.; Angel M, E. Del [CNSNS, Dr. Barragan No. 779, 03020 Mexico D.F. (Mexico)]. E-mail: ragarcia@cnsns.gob.mx

    2003-07-01

    The present work describes the pattern of the denominated installation Phebus developed and used by the National Commission of Nuclear Security and Safeguards for their participation in the International Standard Problem ISP-46, organized by the Nuclear Energy Agency (NEA). The exercise consisted on the simulation of the denominated experiment Phebus FPT1 carried out in the experimental installation Phebus located in the Institut de Protection et de Surete Nucleaire of France. The experiment Phebus FP1 had as objective to evaluate the capacity of different computer codes to model in integral form the physical processes that are carried out during a severe accident in a pressurized water reactor (PWR), from the degradation of the core until the late stage with the formation of a pool of fused material, hydrogen production, liberation and transport of fission products, phenomena in the contention and chemistry of the iodine. The CNSNS uses the version bi of the SCDAPSIM code developed by the company Innovative Software Systems to simulate the International Standard Problem 46. The obtained results showed that the code is able to predict the thermohydraulic part of the experiment, however the same thing doesn't happen to the parameters related with the one fused of the fuel. (Author)

  16. Distribution of radioiodine in soil column experiments with simulations of varying ground water levels

    International Nuclear Information System (INIS)

    Sachse, R.; Paetzold, G.

    1993-01-01

    Results of long-term experiments with 129 I-labelling under field conditions show faster migration of iodine in deeper soil layers for an orthi-eutric fluvisol adjacent to a river as compared to an orthi-humic gleysol without river vicinity. This observation suggests a possible influence of ground water level variations on radioiodine sorption to soil constituents. To verify these findings, experiments with undisturbed soil columns are carried out with controlled moisture regimes. The soil columns are labelled with 125 I and exposed to simulated rainfall or to extreme variations in ground water levels caused by daily pumping cycles. Both watering conditions affect the migration of radioiodine into deeper soil layers. After an experimental period of 25 days it could be detected down to 10 cm below the soil surface. The highest concentrations are found in the 0-2 cm layer. However, in case of the rainfall simulation the radioiodine concentrations in this layer are remarkably higher as compared to those of the experiments with ground water variations. Only the rainfall exposed soil columns show differences between the two soils with respect to tracer depth profiles. An especially fast migration of radioiodine occurs, when the tracer is applied on a water saturated soil column and the soil water is soaked from the bottom immediately after the application. (orig.) [de

  17. GEANT4-based full simulation of the PADME experiment at the DAΦNE BTF

    Science.gov (United States)

    Leonardi, E.; Kozhuharov, V.; Raggi, M.; Valente, P.

    2017-10-01

    A possible solution to the dark matter problem postulates that dark particles can interact with Standard Model particles only through a new force mediated by a “portal”. If the new force has a U(1) gauge structure, the “portal” is a massive photon-like vector particle, called dark photon or A‧. The PADME experiment at the DAΦNE Beam-Test Facility (BTF) in Frascati is designed to detect dark photons produced in positron on fixed target annihilations decaying to dark matter (e+e-→γA‧) by measuring the final state missing mass. The experiment will be composed of a thin active diamond target where a 550 MeV positron beam will impinge to produce e+e- annihilation events. The surviving beam will be deflected with a magnet while the photons produced in the annihilation will be measured by a calorimeter composed of BGO crystals. To reject the background from Bremsstrahlung gamma production, a set of segmented plastic scintillator vetoes will be used to detect positrons exiting the target with an energy lower than that of the beam, while a fast small angle calorimeter will be used to reject the e+e-→γγ(γ) background. To optimize the experimental layout in terms of signal acceptance and background rejection, the full layout of the experiment was modelled with the GEANT4 simulation package. In this paper we will describe the details of the simulation and report on the results obtained with the software.

  18. Results of two-phase natural circulation in hot-leg U-bend simulation experiments

    International Nuclear Information System (INIS)

    Ishii, M.; Lee, S.Y.; Abou El-Seoud, S.

    1987-01-01

    In order to study the two-phase natural circulation and flow termination during a small break loss of coolant accident in LWR, simulation experiments have been performed using two different thermal-hydraulic loops. The main focus of the experiment was the two-phase flow behavior in the hot-leg U-bend typical of BandW LWR systems. The first group of experiments was carried out in the nitrogen gas-water adiabatic simulation loop and the second in the Freon 113 boiling and condensation loop. Both of the loops have been designed as a flow visualization facility and built according to the two-phase flow scaling criteria developed under this program. The nitrogen gas-water system has been used to isolate key hydrodynamic phenomena such as the phase distribution, relative velocity between phases, two-phase flow regimes and flow termination mechanisms, whereas the Freon loop has been used to study the effect of fluid properties, phase changes and coupling between hydrodynamic and heat transfer phenomena. Significantly different behaviors have been observed due to the non-equilibrium phase change phenomena such as the flashing and condensation in the Freon loop. The phenomena created much more unstable hydrodynamic conditions which lead to cyclic or oscillatory flow behaviors

  19. Perceived learning outcome: the relationship between experience, realism and situation awareness during simulator training.

    Science.gov (United States)

    Saus, Evelyn-Rose; Johnsen, Bjørn Helge; Eid, Jarle

    2010-01-01

    Navigation errors are a frequent cause of serious accidents and work-related injuries among seafarers. The present study investigated the effects of experience, perceived realism, and situation awareness (SA) on the perceived learning outcome of simulator-based navigation training. Thirty-two Norwegian Navy officer cadets were assigned to a low and a high mental workload conditions based on previous educational and navigational experience. In the low mental workload condition, experience (negatively associated), perceived realism, and subjective SA explained almost half of the total variance in perceived learning outcome. A hierarchical regression analysis showed that only subjective SA made a unique contribution to the learning outcome. In the high mental workload condition, perceived realism and subjective SA together explained almost half of the variance in perceived learning outcome. Furthermore, both perceived realism and subjective SA were shown to make an independent contribution to perceived learning outcomes. The results of this study show that in order to enhance the learning outcomes from simulator training it is necessary to design training procedures and scenarios that enable students to achieve functional fidelity and to generate and maintain SA during training. This can further improve safety and reduce the risk of maritime disasters.

  20. Application of neural network technology to setpoint control of a simulated reactor experiment loop

    International Nuclear Information System (INIS)

    Cordes, G.A.; Bryan, S.R.; Powell, R.H.; Chick, D.R.

    1991-01-01

    This paper describes the design, implementation, and application of artificial neural networks to achieve temperature and flow rate control for a simulation of a typical experiment loop in the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory (INEL). The goal of the project was to research multivariate, nonlinear control using neural networks. A loop simulation code was adapted for the project and used to create a training set and test the neural network controller for comparison with the existing loop controllers. The results for the best neural network design are documented and compared with existing loop controller action. The neural network was shown to be as accurate at loop control as the classical controllers in the operating region represented by the training set. 5 refs., 8 figs., 3 tabs

  1. Regional Climate Simulation Experiments with a Variable Resolution Stretched Grid GCM

    Science.gov (United States)

    Takacs, Lawrence L.; Stein, Uri; Govindaraju, Ravi C.

    1999-01-01

    The variable resolution stretched grid (SG) version of the Goddard Earth Observing System (GEOS) GCM has been recently developed and tested in a regional climate simulation mode. The SG-approach is an alternative to the widely used nested grid approach introduced a decade ago as a pioneering step to regional climate modeling. The region of interest with a uniform about 60 km resolution used in experiments is a rectangle over the U.S. The results of one annual as well as two-month simulations for the anomalous climate event of the U.S. drought of 1988, are validated against data analysis fields and diagnostics. The efficient regional down-scaling as well as the positive impact of fine regional resolution, are obtained. The SG-concept appeared to be a promising candidate for regional and subregional climate studies and applications.

  2. The two dynamical states in sinusoidal potentials: An analog simulation experiment

    Science.gov (United States)

    Sawkmie, Ivan Skhem; Mahato, Mangal C.

    2018-04-01

    The phenomenon of stochastic resonance (SR) is usually found to occur theoretically as well as experimentally in bi-stable systems [1]. Recently, it was numerically shown that SR is found to occur in underdamped (friction coefficient γ) sinusoidal potentials also. The occurrence of SR is explained in terms of two competing dynamical states of trajectories as a response to the external periodic drive. We setup an analog simulation experiment similar to the analog simulation work done earlier to study stochastic nonlinear dynamics [2], to verify the existence of the two dynamical states and to investigate the occurrence of SR in sinusoidal potentials obtained earlier [3]. We discuss our experimental setup and the results obtained in detail.

  3. Sequential UASB and dual media packed-bed reactors for domestic wastewater treatment - experiment and simulation.

    Science.gov (United States)

    Rodríguez-Gómez, Raúl; Renman, Gunno

    2016-01-01

    A wastewater treatment system composed of an upflow anaerobic sludge blanket (UASB) reactor followed by a packed-bed reactor (PBR) filled with Sorbulite(®) and Polonite(®) filter material was tested in a laboratory bench-scale experiment. The system was operated for 50 weeks and achieved very efficient total phosphorus (P) removal (99%), 7-day biochemical oxygen demand removal (99%) and pathogenic bacteria reduction (99%). However, total nitrogen was only moderately reduced in the system (40%). A model focusing on simulation of organic material, solids and size of granules was then implemented and validated for the UASB reactor. Good agreement between the simulated and measured results demonstrated the capacity of the model to predict the behaviour of solids and chemical oxygen demand, which is critical for successful P removal and recovery in the PBR.

  4. A study on experiment and numerical simulation of heat exchanger in heating furnace

    Directory of Open Access Journals (Sweden)

    Z. C. Lv

    2018-01-01

    Full Text Available In this paper, air preheater is used the research object and its heat transfer law is studied by experiment and numerical simulation. The experimental data showed that with the increases of inlet air velocity, the comprehensive heat transfer coefficient and heat transfer efficiency increase, but the temperature efficiency decreases and the resistance loss on the air side increases. The numerical simulation results showed that the larger the diameter of the tube, the better the heat transfer effect. When horizontal spacing in the range of 290 - 305 mm and longitudinal spacing is 70 - 90 mm, the heat transfer effect is best. The optimized heat exchanger structure is that diameter is 60 mm, horizontal spacing is 300 mm, longitudinal spacing is 90 mm. As the inlet air flow rate increases, the heat transfer efficiency increases, but the temperature efficiency decreases and the resistance loss on the air side increases.

  5. Photoelectric Franck-Hertz experiment and its kinetic analysis by Monte Carlo simulation.

    Science.gov (United States)

    Magyar, Péter; Korolov, Ihor; Donkó, Zoltán

    2012-05-01

    The electrical characteristics of a photoelectric Franck-Hertz cell are measured in argon gas over a wide range of pressure, covering conditions where elastic collisions play an important role, as well as conditions where ionization becomes significant. Photoelectron pulses are induced by the fourth harmonic UV light of a diode-pumped Nd:YAG laser. The electron kinetics, which is far more complex compared to the naive picture of the Franck-Hertz experiment, is analyzed via Monte Carlo simulation. The computations provide the electrical characteristics of the cell, the energy and velocity distribution functions, and the transport parameters of the electrons, as well as the rate coefficients of different elementary processes. A good agreement is obtained between the cell's measured and calculated electrical characteristics, the peculiarities of which are understood by the simulation studies.

  6. Experiment and simulation study on unidirectional carbon fiber composite component under dynamic 3 point bending loading

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guowei; Sun, Qingping; Zeng, Danielle; Li, Dayong; Su, Xuming

    2018-04-10

    In current work, unidirectional (UD) carbon fiber composite hatsection component with two different layups are studied under dynamic 3 point bending loading. The experiments are performed at various impact velocities, and the effects of impactor velocity and layup on acceleration histories are compared. A macro model is established with LS-Dyna for more detailed study. The simulation results show that the delamination plays an important role during dynamic 3 point bending test. Based on the analysis with high speed camera, the sidewall of hatsection shows significant buckling rather than failure. Without considering the delamination, current material model cannot capture the post failure phenomenon correctly. The sidewall delamination is modeled by assumption of larger failure strain together with slim parameters, and the simulation results of different impact velocities and layups match the experimental results reasonable well.

  7. Is Motor Simulation Involved During Foreign Language Learning? A Virtual Reality Experiment

    Directory of Open Access Journals (Sweden)

    Claudia Repetto

    2015-10-01

    Full Text Available This article presents a study performed to investigate the role of simulation in second language learning while using a virtual environment. Participants were asked to explore a virtual park while learning 15 new Czech verbs (action verbs that describe movements performed with either the hand or the foot, and abstract verbs. This learning condition was compared with a baseline condition, where movements (either virtual or real were not allowed. The goal was to investigate whether the virtual action (performed with the feet would promote or interfere with the learning of verbs describing actions that were performed with the same or a different effector. The number of verbs correctly remembered in a free recall task was computed, along with reaction times and number of errors during a recognition task. Results show that the simulation per se has no effect in verbal learning, but the features of the virtual experience mediate it.

  8. Neutral Transport Simulations of Gas Puff Imaging Experiments on Alcator C-Mod

    International Nuclear Information System (INIS)

    Stotler, D.P.; LaBombard, B.; Terry, J.L.; Zweben, S.J.

    2002-01-01

    Visible imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results.Visibl e imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results

  9. Theory and simulation of an inverse free-electron laser experiment

    Science.gov (United States)

    Gou, S. K.; Bhattacharjee, A.; Fang, J.-M.; Marshall, T. C.

    1997-03-01

    An experimental demonstration of the acceleration of electrons using a high-power CO2 laser interacting with a relativistic electron beam moving along a wiggler has been carried out at the Accelerator Test Facility of the Brookhaven National Laboratory [Phys. Rev. Lett. 77, 2690 (1996)]. The data generated by this inverse free-electron-laser (IFEL) experiment are studied by means of theory and simulation. Included in the simulations 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; energy spread of the electrons; and arbitrary wiggler-field profile. Two types of wiggler profile are considered: a linear taper of the period, and a step-taper of the period. (The period of the wiggler is ˜3 cm, its magnetic field is ˜1 T, and the wiggler length is 0.47 m.) 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 (˜40 MeV). At a laser power level ˜0.5 Gw, the simulation results on energy gain are in reasonable agreement with the experimental results. Preliminary results on the electron energy distribution at the end of the IFEL are presented. Whereas the experiment produces a near-monotone distribution of electron energies with the peak shifted to higher energy, the simulation shows a more structured and non-monotonic distribution at the end of the wiggler. Effects that may help reconcile these differences are considered.

  10. Magnetohydrodynamic simulation of solid-deuterium-initiated Z-pinch experiments

    International Nuclear Information System (INIS)

    Sheehey, P.T.

    1994-02-01

    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 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

  11. Modeling of precipitation and Cr depletion profiles of Inconel 600 during heat treatments and LSM procedure

    Energy Technology Data Exchange (ETDEWEB)

    Bao Gang [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Shinozaki, Kenji [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan)]. E-mail: kshino@hiroshima-u.ac.jp; Inkyo, Muneyuki [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Miyoshi, Tomohisa [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Yamamoto, Motomichi [Department of Mechanical System Engineering, Hiroshima University, 1-4-1 Higashi-Hiroshima, Hiroshima (Japan); Mahara, Yoichi [Babcock-Hitachi K.K., 3-36 Takara-machi, Kure, Hiroshima (Japan); Watanabe, Hiroshi [Babcock-Hitachi K.K., 3-36 Takara-machi, Kure, Hiroshima (Japan)

    2006-08-10

    A model based on the thermodynamic and kinetic was conducted to simulate the Cr depletion profiles near the grain boundary in Inconel 600 during the heat treatments and laser surface melting (LSM) process using Thermo-Calc and Dictra code. Based on the good agreement of Cr concentration distribution during heat treatments measured by experiments, the microsegregation of Cr induced by cellular microstructure formed during the LSM process was also modeled. The Cr depletion profile was evaluated using the Cr depletion area below the critical Cr concentration for intergranular cracking/intergranular stress corrosion cracking (IGC/IGSCC) susceptibility (8 mass%). Comparing with the result of Streicher test, the Cr depletion area calculated showed good coherence with the IGC/IGSCC susceptibility. The sample after SR + LTS treatment with the largest Cr depletion area showed the worst IGC/IGSCC resistance, while, the sample after LSM process with the smaller Cr depletion area showed the excellent IGC/IGSCC resistance.

  12. Detecting Structural Features in Metallic Glass via Synchrotron Radiation Experiments Combined with Simulations

    Directory of Open Access Journals (Sweden)

    Gu-Qing Guo

    2015-11-01

    Full Text Available Revealing the essential structural features of metallic glasses (MGs will enhance the understanding of glass-forming mechanisms. In this work, a feasible scheme is provided where we performed the state-of-the-art synchrotron-radiation based experiments combined with simulations to investigate the microstructures of ZrCu amorphous compositions. It is revealed that in order to stabilize the amorphous state and optimize the topological and chemical distribution, besides the icosahedral or icosahedral-like clusters, other types of clusters also participate in the formation of the microstructure in MGs. This cluster-level co-existing feature may be popular in this class of glassy materials.

  13. The assessment of containment codes by experiments simulating severe accident scenarios

    International Nuclear Information System (INIS)

    Karwat, H.

    1992-01-01

    Hitherto, a generally applicable validation matrix for codes simulating the containment behaviour under severe accident conditions did not exist. Past code applications have shown that most problems may be traced back to inaccurate thermalhydraulic parameters governing gas- or aerosol-distribution events. A provisional code-validation matrix is proposed, based on a careful selection of containment experiments performed during recent years in relevant test facilities under various operating conditions. The matrix focuses on the thermalhydraulic aspects of the containment behaviour after severe accidents as a first important step. It may be supplemented in the future by additional suitable tests

  14. Simulations of Super Alfvenic Laser Ablation Experiments in the Large Plasma Device

    Science.gov (United States)

    Clark, Stephen Eric

    Hybrid plasma simulations, consisting of kinetic ions treated using standard Particle- In-Cell (PIC) techniques and an inertialess charge-neutralizing electron fluid, have been used to investigate the properties of collisionless shocks for a number of years. They agree well with sparse data obtained by flying through Earth's bow shock and have been used to model high energy explosions in the ionosphere. In this doctoral dissertation hybrid plasma simulation is used on much smaller scales to model collisionless shocks in a controlled laboratory setting. Initially a two-dimensional hybrid code from Los Alamos National Laboratory was used to find the best experimental parameters for shock formation, and interpret experimental data. It was demonstrated using the hybrid code that the experimental parameters needed to generate a shock in the laboratory are relaxed compared to previous work that was done. It was also shown that stronger shocks can be generated when running into a density gradient. Laboratory experiments at the University of California at Los Angeles using the high energy kJ-class Nd:Glass 1053 nm Raptor laser, and later the low energy yet high repetition rate 25 J Nd:Glass 1053 nm Peening laser have been performed in the Large Plasma Device (LAPD), which have provided some much needed data to benchmark the hybrid simulation method. The LAPD provides a repeatable, quiescent, ambient magnetized plasma to surround the exploding laser produced plasma that is ablated from a High Density Polyethylene (HDPE) target. The plasma density peaks in the machine at ni O(1013 cm-3 ), which is sufficiently dense to strongly couple energy and momentum from a laser ablated carbon plasma ejected from the HDPE target into the magnetized ambient plasma. It has been demonstrated that a sub-critical shock is formed in the LAPD using the high energy Raptor laser, though the data from this experiment is scant. Hybrid simulation was used as an analysis tool for the shock

  15. Simulation of the MHD stabilities of the experiment on HL-2A tokamak by GATO code

    International Nuclear Information System (INIS)

    Pan Wei; Chen Liaoyuan; Dong Jiaqi; Shen Yong; Zhang Jinhua

    2009-01-01

    The ideal two-dimensional MHD stabilities code, GATO, has been successfully immigrated to the high-performance computing system of HL-2A and used to the simulation study of the ideal MHD stabilities of the plasmas produced by one of the pellets injection experiments on HL-2A tokamak. The EFIT code was used to reconstruct the equilibrium configures firstly and the GATO was used to compute their MHD stabilities secondly whose source data were obtained by the NO.4050 discharge of the experiments on HL-2A, and finally by analyzing these results the preliminary conclusion was devised that the confinement performance of the plasma was improved because of the stabilization effect of the anti-sheared configures created by the pellets injection. (authors)

  16. Melting of rare-gas crystals: Monte Carlo simulation versus experiments.

    Science.gov (United States)

    Bocchetti, V; Diep, H T

    2013-03-14

    We study the melting transition in crystals of rare gas Ar, Xe, and Kr by the use of extensive Monte Carlo simulations with the Lennard-Jones potential. The parameters of this potential have been deduced by Bernardes in 1958 from experiments of rare gas in the gaseous phase. It is amazing that the parameters of such a popular potential were not fully tested so far. Using the Bernardes parameters, we find that the melting temperature of several rare gas is from 13% to 20% higher than that obtained from experiments. We have throughout studied the case of Ar by examining both finite-size and cutoff-distance effects. In order to get a good agreement with the experimental melting temperature, we propose a modification of these parameters to describe better the melting of rare-gas crystals.

  17. Modelling and simulation in nuclear safety and the role of experiment

    International Nuclear Information System (INIS)

    Baek, W-P.

    2015-01-01

    'Full text:' Modeling and simulation (M&S) technology is a key element in assuring and enhancing the safety of nuclear installations. The M&S technology has been progressed continuously with the introduction of new designs, improved understanding on relevant physical processes, and the improvement of computing environment. This presentation covers the role, progresses and prospect of M&S technology relevant to nuclear safety. Special attention is given to the effective interaction between M&S and experiment. The expected role of experiment to motivate the advancement of M&S technology is emphasized with some typical examples. Finally, relevant R&D activities of Korea are introduced for thermal-hydraulics and severe accident safety. (author)

  18. Nuclear waste repository simulation experiments. Asse salt mine: Annual report 1984

    International Nuclear Information System (INIS)

    Rothfuchs, T.; Feddersen, H.K.; Schwarzianeck, P.; Staupendahl, G.; Coyle, A.J.; Kalia, H.; Eckert, J.

    1985-01-01

    This is the Second Annual Report (1984) which describes experiments simulating a nuclear waste repository at the 800 meter-level of the Asse Salt Mine in the Federal Republic of Germany. The report describes the Asse Salt Mine, the test equipment, and the pretest properties of the salt in the mine and in the vicinity of the test area. Also included are test data for the first sixteen months of operation on the following: brine migration rates, thermal mechanical behavior of the salt (including room closure, stress readings and thermal profiles) and borehole gas pressures. In addition to field data laboratory analyses of results are also included in this report. The duration of the experiment will be two years, ending in December 1985. (orig.)

  19. Nuclear waste repository simulation experiments, Asse salt mine, Federal Republic of Germany. Annual report 1984

    International Nuclear Information System (INIS)

    Rothfuchs, T.; Feddersen, H.K.; Schwarzianeck, P.; Staupendahl, G.; Coyle, A.J.; Eckert, J.; Kalia, H.

    1986-07-01

    This is the second joint annual report (1984) on experiments simulating a nuclear waste repository at the 800-m (2624-ft) level of the Asse salt mine in the Federal Republic of Germany. This report describes the Asse salt mine, the test equipment, and the pretest properties of the salt in the mine and in the vicinity of the test area. Also included are test data for the first 19 months of operation on the following: brine migration rates, thermal mechanical behavior of the salt (including room closure, stress reading, and thermal profiles), and borehole gas pressures. In addition to field data, laboratory analyses of results are included in this report. The duration of the experiment will be 2 years, ending in December 1985

  20. Numerical simulation and comparison with experiment for self-excited oscillations in a diffuser flow

    Science.gov (United States)

    Hsieh, T.; Bogar, T. J.; Coakley, T. J.

    1985-01-01

    This paper describes numerical simulations of self-excited oscillations in a two-dimensional transonic diffuser flow obtained by solving the Navier-Stokes equations with a two-equation turbulence model. Comparisons were made between the computational results and experimental data. For the mean flowfields, the agreement between computation and experiment is good for the wall pressures, shock location, and the separation and reattachment points. However, the thickness of the computed recirculation zone is about 50 percent of the measured thickness. For the fluctuating flowfields, a great deal of qualitative similarity exists between the computation and experiment; however, the predicted oscillation frequency is about 50 percent higher than the measured value. The formation of a succession of downstream-traveling counter-rotating vortices, as seen experimentally, is also vividly displayed in the numerical results.

  1. New tools and technology for the study of human performance in simulator experiments

    Energy Technology Data Exchange (ETDEWEB)

    Droeivoldsmo, Asgeir

    2003-07-01

    This thesis suggests that new tools and technology can be used for production of relevant data and insights from the study of human performance in simulator and field experiments. It examines some of the theoretical perspectives behind data collection and human performance assessment, and argues for a high resemblance of the real world and use of subject matter expertise in simulator studies. A model is proposed, suggesting that human performance measurement should be tightly coupled to the topic of study and have a close connection to the time line. This coupling requires new techniques for continuous data collection, and eye movement tracking has been identified as a promising basis for this type of measures. One way of improving realism is to create virtual environments allowing for controlling more of the environment surrounding the test subjects. New application areas for virtual environments are discussed for use in control room and field studies. The combination of wearable computing, virtual and augmented (the use of computers to overlay virtual information onto the real world) reality provides many new possibilities to present information to operators. In two experiments, virtual and augmented reality techniques were used to visualise radiation fields for operators in a contaminated nuclear environment. This way the operators could train for and execute their tasks in a way that minimised radiation exposure to the individual operator. Both experiments were successful in proving the concept of radiation visualisation. Virtual environments allow for early end-user feedback in the design and refurbishment of control room man-machine interfaces. The practical usability of VR in the control room setting was tested in two control room design experiments. The results show that with the right tools for solving the tasks under test, even desktop presentations of the virtual environment can provide sufficient resemblance of the real world. Computerised data

  2. Simulation of KAEVER experiments on aerosol behavior in a nuclear power plant containment at accident conditions with the ASTEC code

    International Nuclear Information System (INIS)

    Kljenak, I.; Mavko, B.

    2006-01-01

    Experiments on aerosol behaviour in saturated and non-saturated atmosphere, which were performed in the KAEVER experimental facility, were simulated with the severe accident computer code ASTEC CPA V1.2. The specific purpose of the work was to assess the capability of the code to model aerosol condensation and deposition in the containment of a light-water-reactor nuclear power plant at severe accident conditions, if the atmosphere saturation conditions are simulated adequately. Five different tests were first simulated with boundary conditions, obtained from the experiments. In all five tests, a non-saturated atmosphere was simulated, although, in four tests, the atmosphere was allegedly saturated. The simulations were repeated with modified boundary conditions, to obtain a saturated atmosphere in all tests. Results of dry and wet aerosol concentrations in the test vessel atmosphere for both sets of simulations are compared to experimental results. (author)

  3. Results from Real Time Simulation Experiment of an Integrated Concept for UAV/Direct Fire Weapon Systems

    National Research Council Canada - National Science Library

    Melendez, Gerardo; Gallivan, Elizabeth; Kenneally, William; SantaPietro, John; Wiener, Stephen

    2006-01-01

    During the last several years, there have been a large number of design studies, system simulations, and battlelab experiments that have sought to improve the integration of UAV-based sensor systems...

  4. Students' perceptions of their learning experiences using high-fidelity simulation to teach concepts relative to obstetrics.

    Science.gov (United States)

    Partin, Jan L; Payne, Teresa A; Slemmons, Marina F

    2011-01-01

    In this era of expanding technology, amidst a shortage of nursing faculty and clinical sites, there has been increasing emphasis on the use of simulation to enhance clinical learning. The purpose of this qualitative, descriptive study was to describe students' self-perceptions of their learning experiences using high-fidelity simulation in teaching concepts relative to obstetrics. A sample of 60 second-year associate of science in nursing (ASN) students attended simulation experiences in obstetrics in addition to required clinical time in a hospital. At the end of each simulated learning experience, students audiotaped their reflections of the experience. Content analysis was done to identify themes in the students' perceptions relative to their learning. Three themes were identified from the analysis: the nonthreatening environment, enhancement of learning, and feeling prepared for practice.

  5. Spectral analysis of forecast error investigated with an observing system simulation experiment

    Directory of Open Access Journals (Sweden)

    Nikki C. Privé

    2015-02-01

    Full Text Available The spectra of analysis and forecast error are examined using the observing system simulation experiment framework developed at the National Aeronautics and Space Administration Global Modeling and Assimilation Office. A global numerical weather prediction model, the Global Earth Observing System version 5 with Gridpoint Statistical Interpolation data assimilation, is cycled for 2 months with once-daily forecasts to 336 hours to generate a Control case. Verification of forecast errors using the nature run (NR as truth is compared with verification of forecast errors using self-analysis; significant underestimation of forecast errors is seen using self-analysis verification for up to 48 hours. Likewise, self-analysis verification significantly overestimates the error growth rates of the early forecast, as well as mis-characterising the spatial scales at which the strongest growth occurs. The NR-verified error variances exhibit a complicated progression of growth, particularly for low wavenumber errors. In a second experiment, cycling of the model and data assimilation over the same period is repeated, but using synthetic observations with different explicitly added observation errors having the same error variances as the control experiment, thus creating a different realisation of the control. The forecast errors of the two experiments become more correlated during the early forecast period, with correlations increasing for up to 72 hours before beginning to decrease.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Spectral Analysis of Forecast Error Investigated with an Observing System Simulation Experiment

    Science.gov (United States)

    Prive, N. C.; Errico, Ronald M.

    2015-01-01

    The spectra of analysis and forecast error are examined using the observing system simulation experiment (OSSE) framework developed at the National Aeronautics and Space Administration Global Modeling and Assimilation Office (NASAGMAO). A global numerical weather prediction model, the Global Earth Observing System version 5 (GEOS-5) with Gridpoint Statistical Interpolation (GSI) data assimilation, is cycled for two months with once-daily forecasts to 336 hours to generate a control case. Verification of forecast errors using the Nature Run as truth is compared with verification of forecast errors using self-analysis; significant underestimation of forecast errors is seen using self-analysis verification for up to 48 hours. Likewise, self analysis verification significantly overestimates the error growth rates of the early forecast, as well as mischaracterizing the spatial scales at which the strongest growth occurs. The Nature Run-verified error variances exhibit a complicated progression of growth, particularly for low wave number errors. In a second experiment, cycling of the model and data assimilation over the same period is repeated, but using synthetic observations with different explicitly added observation errors having the same error variances as the control experiment, thus creating a different realization of the control. The forecast errors of the two experiments become more correlated during the early forecast period, with correlations increasing for up to 72 hours before beginning to decrease.

  8. Holliday Junction Thermodynamics and Structure: Coarse-Grained Simulations and Experiments

    Science.gov (United States)

    Wang, Wujie; Nocka, Laura M.; Wiemann, Brianne Z.; Hinckley, Daniel M.; Mukerji, Ishita; Starr, Francis W.

    2016-03-01

    Holliday junctions play a central role in genetic recombination, DNA repair and other cellular processes. We combine simulations and experiments to evaluate the ability of the 3SPN.2 model, a coarse-grained representation designed to mimic B-DNA, to predict the properties of DNA Holliday junctions. The model reproduces many experimentally determined aspects of junction structure and stability, including the temperature dependence of melting on salt concentration, the bias between open and stacked conformations, the relative populations of conformers at high salt concentration, and the inter-duplex angle (IDA) between arms. We also obtain a close correspondence between the junction structure evaluated by all-atom and coarse-grained simulations. We predict that, for salt concentrations at physiological and higher levels, the populations of the stacked conformers are independent of salt concentration, and directly observe proposed tetrahedral intermediate sub-states implicated in conformational transitions. Our findings demonstrate that the 3SPN.2 model captures junction properties that are inaccessible to all-atom studies, opening the possibility to simulate complex aspects of junction behavior.

  9. Semi-automated operation of Mars Climate Simulation chamber - MCSC modelled for biological experiments

    Science.gov (United States)

    Tarasashvili, M. V.; Sabashvili, Sh. A.; Tsereteli, S. L.; Aleksidze, N. D.; Dalakishvili, O.

    2017-10-01

    The Mars Climate Simulation Chamber (MCSC) (GEO PAT 12 522/01) is designed for the investigation of the possible past and present habitability of Mars, as well as for the solution of practical tasks necessary for the colonization and Terraformation of the Planet. There are specific tasks such as the experimental investigation of the biological parameters that allow many terrestrial organisms to adapt to the imitated Martian conditions: chemistry of the ground, atmosphere, temperature, radiation, etc. MCSC is set for the simulation of the conduction of various biological experiments, as well as the selection of extremophile microorganisms for the possible Settlement, Ecopoesis and/or Terraformation purposes and investigation of their physiological functions. For long-term purposes, it is possible to cultivate genetically modified organisms (e.g., plants) adapted to the Martian conditions for future Martian agriculture to sustain human Mars missions and permanent settlements. The size of the chamber allows preliminary testing of the functionality of space-station mini-models and personal protection devices such as space-suits, covering and building materials and other structures. The reliability of the experimental biotechnological materials can also be tested over a period of years. Complex and thorough research has been performed to acquire the most appropriate technical tools for the accurate engineering of the MCSC and precious programmed simulation of Martian environmental conditions. This paper describes the construction and technical details of the equipment of the MCSC, which allows its semi-automated, long-term operation.

  10. Monte-Carlo simulations of different concepts for shielding in the ATLAS experiment forward region

    CERN Document Server

    Stekl, I; Eschbach, R; Kovalenko, V E; Leroy, C; Marquet, C; Palla, J; Piquemal, F; Pospísil, S; Shupe, M A; Sodomka, J; Tourneur, S; Vorobel, V

    2001-01-01

    The role and performance of various layers (steel, cast iron (CI), concrete, lead, borated polyethylene (BPE), lithium filled polyethylene (LiPE)) and their combinations as shielding against neutrons and photons in the ATLAS experiment forward region (JF shielding) has been studied by means of Monte-Carlo simulations. These simulations permitted one to determine the locations of appearance and disappearance of neutrons and photons and their number at this location. In particular, the determination of the number of newly born neutrons and photons, the number of stopped neutrons and photons, as well as the number of neutrons and photons crossing the borders of shielding layers allowed the assessment of the efficiency of the JF shielding. It provided a basis for comparing the merits of different configurations of shielding layers. The simulation code is based on GEANT, FLUKA, MICAP and GAMLIB. The results of the study give strong support to a segmented shielding made of five layers (steel, CI, BPE, steel, LiPE).

  11. X-ray strain tensor imaging: FEM simulation and experiments with a micro-CT.

    Science.gov (United States)

    Kim, Jae G; Park, So E; Lee, Soo Y

    2014-01-01

    In tissue elasticity imaging, measuring the strain tensor components is necessary to solve the inverse problem. However, it is impractical to measure all the tensor components in ultrasound or MRI elastography because of their anisotropic spatial resolution. The objective of this study is to compute 3D strain tensor maps from the 3D CT images of a tissue-mimicking phantom. We took 3D micro-CT images of the phantom twice with applying two different mechanical compressions to it. Applying the 3D image correlation technique to the CT images under different compression, we computed 3D displacement vectors and strain tensors at every pixel. To evaluate the accuracy of the strain tensor maps, we made a 3D FEM model of the phantom, and we computed strain tensor maps through FEM simulation. Experimentally obtained strain tensor maps showed similar patterns to the FEM-simulated ones in visual inspection. The correlation between the strain tensor maps obtained from the experiment and the FEM simulation ranges from 0.03 to 0.93. Even though the strain tensor maps suffer from high level noise, we expect the x-ray strain tensor imaging may find some biomedical applications such as malignant tissue characterization and stress analysis inside the tissues.

  12. Simulation of physics in the presence of pile-up at the ATLAS experiment

    CERN Document Server

    Haas, A; The ATLAS collaboration

    2012-01-01

    We are now in a regime where we observe substantial multiple proton-proton collisions within each filled LHC bunch-crossing and also multiple filled bunch-crossings within the sensitive time window of the ATLAS detector. This will increase with increased luminosity in the near future. Including these effects in Monte Carlo simulation poses significant computing challenges. We present a description of the standard approach used by the ATLAS experiment and details of how we manage the conflicting demands of keeping the background dataset size as small as possible while minimizing the effect of background event re-use. We also present details of the methods used to minimize the memory footprint of these digitization jobs, to keep them within the grid limit, despite combining the information from thousands of simulated events at once. We also describe an alternative approach, known as Overlay. Here, the actual detector conditions are sampled from raw data using a special zero-bias trigger, and the simulated physi...

  13. Shock experiments and numerical simulations on low energy portable electrically exploding foil accelerators

    International Nuclear Information System (INIS)

    Saxena, A. K.; Kaushik, T. C.; Gupta, Satish C.

    2010-01-01

    Two low energy (1.6 and 8 kJ) portable electrically exploding foil accelerators are developed for moderately high pressure shock studies at small laboratory scale. Projectile velocities up to 4.0 km/s have been measured on Kapton flyers of thickness 125 μm and diameter 8 mm, using an in-house developed Fabry-Perot velocimeter. An asymmetric tilt of typically few milliradians has been measured in flyers using fiber optic technique. High pressure impact experiments have been carried out on tantalum, and aluminum targets up to pressures of 27 and 18 GPa, respectively. Peak particle velocities at the target-glass interface as measured by Fabry-Perot velocimeter have been found in good agreement with the reported equation of state data. A one-dimensional hydrodynamic code based on realistic models of equation of state and electrical resistivity has been developed to numerically simulate the flyer velocity profiles. The developed numerical scheme is validated against experimental and simulation data reported in literature on such systems. Numerically computed flyer velocity profiles and final flyer velocities have been found in close agreement with the previously reported experimental results with a significant improvement over reported magnetohydrodynamic simulations. Numerical modeling of low energy systems reported here predicts flyer velocity profiles higher than experimental values, indicating possibility of further improvement to achieve higher shock pressures.

  14. Climate and atmosphere simulator for experiments on ecological systems in changing environments.

    Science.gov (United States)

    Verdier, Bruno; Jouanneau, Isabelle; Simonnet, Benoit; Rabin, Christian; Van Dooren, Tom J M; Delpierre, Nicolas; Clobert, Jean; Abbadie, Luc; Ferrière, Régis; Le Galliard, Jean-François

    2014-01-01

    Grand challenges in global change research and environmental science raise the need for replicated experiments on ecosystems subjected to controlled changes in multiple environmental factors. We designed and developed the Ecolab as a variable climate and atmosphere simulator for multifactor experimentation on natural or artificial ecosystems. The Ecolab integrates atmosphere conditioning technology optimized for accuracy and reliability. The centerpiece is a highly contained, 13-m(3) chamber to host communities of aquatic and terrestrial species and control climate (temperature, humidity, rainfall, irradiance) and atmosphere conditions (O2 and CO2 concentrations). Temperature in the atmosphere and in the water or soil column can be controlled independently of each other. All climatic and atmospheric variables can be programmed to follow dynamical trajectories and simulate gradual as well as step changes. We demonstrate the Ecolab's capacity to simulate a broad range of atmospheric and climatic conditions, their diurnal and seasonal variations, and to support the growth of a model terrestrial plant in two contrasting climate scenarios. The adaptability of the Ecolab design makes it possible to study interactions between variable climate-atmosphere factors and biotic disturbances. Developed as an open-access, multichamber platform, this equipment is available to the international scientific community for exploring interactions and feedbacks between ecological and climate systems.

  15. Sci—Fri PM: Topics — 05: Experience with linac simulation software in a teaching environment

    International Nuclear Information System (INIS)

    Carlone, Marco; Harnett, Nicole; Jaffray, David; Norrlinger, Bern; Prooijen, Monique van; Milne, Emily

    2014-01-01

    Medical linear accelerator education is usually restricted to use of academic textbooks and supervised access to accelerators. To facilitate the learning process, simulation software was developed to reproduce the effect of medical linear accelerator beam adjustments on resulting clinical photon beams. The purpose of this report is to briefly describe the method of operation of the software as well as the initial experience with it in a teaching environment. To first and higher orders, all components of medical linear accelerators can be described by analytical solutions. When appropriate calibrations are applied, these analytical solutions can accurately simulate the performance of all linear accelerator sub-components. Grouped together, an overall medical linear accelerator model can be constructed. Fifteen expressions in total were coded using MATLAB v 7.14. The program was called SIMAC. The SIMAC program was used in an accelerator technology course offered at our institution; 14 delegates attended the course. The professional breakdown of the participants was: 5 physics residents, 3 accelerator technologists, 4 regulators and 1 physics associate. The course consisted of didactic lectures supported by labs using SIMAC. At the conclusion of the course, eight of thirteen delegates were able to successfully perform advanced beam adjustments after two days of theory and use of the linac simulator program. We suggest that this demonstrates good proficiency in understanding of the accelerator physics, which we hope will translate to a better ability to understand real world beam adjustments on a functioning medical linear accelerator

  16. Adsorption of HMF from water/DMSO solutions onto hydrophobic zeolites: experiment and simulation.

    Science.gov (United States)

    Xiong, Ruichang; León, Marta; Nikolakis, Vladimiros; Sandler, Stanley I; Vlachos, Dionisios G

    2014-01-01

    The adsorption of 5-hydroxymethylfurfural (HMF), DMSO, and water from binary and ternary mixtures in hydrophobic silicalite-1 and dealuminated Y (DAY) zeolites at ambient conditions was studied by experiments and molecular modeling. HMF and DMSO adsorption isotherms were measured and compared to those calculated using a combination of grand canonical Monte Carlo and expanded ensemble (GCMC-EE) simulations. A method based on GCMC-EE simulations for dilute solutions combined with the Redlich-Kister (RK) expansion (GCMC-EE-RK) is introduced to calculate the isotherms over a wide range of concentrations. The simulations, using literature force fields, are in reasonable agreement with experimental data. In HMF/water binary mixtures, large-pore hydrophobic zeolites are much more effective for HMF adsorption but less selective because large pores allow water adsorption because of H2 O-HMF attraction. In ternary HMF/DMSO/water mixtures, HMF loading decreases with increasing DMSO fraction, rendering the separation of HMF from water/DMSO mixtures by adsorption difficult. The ratio of the energetic interaction in the zeolite to the solvation free energy is a key factor in controlling separation from liquid mixtures. Overall, our findings could have an impact on the separation and catalytic conversion of HMF and the rational design of nanoporous adsorbents for liquid-phase separations in biomass processing. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Influence of displacement gradients on the interpretation of charged particle simulation experiments

    International Nuclear Information System (INIS)

    Garner, F.A.; Guthrie, G.L.

    1975-08-01

    Neutron flux and spectrum gradients are negligible within a single grain of structural materials in fusion reactors. In charged particle simulation, however, substantial gradients exist in the flux of displaced atoms (dpa) along the ion path, which is typically several microns or less in length. In interpretation of such experiments, one must account for the influence of variables that are atypical of the simulated environment. Experimental and modeling studies show that dpa gradients lead to gradients in microstructure, which in turn modify the effect of diffusion on the effective growth environment of voids and other defects. For some ions, these effects are overwhelmed by a phenomenon designated the ''internal temperature shift.'' Although the physical temperature is relatively invariant along the ion path, the temperature regime of swelling shifts as the displacement rate changes. The swelling vs. depth profile is altered substantially from that expected from the dpa profile, and the type of modification is dependent on the relation of the irradiation temperature to the peak swelling temperature at the mean displacement flux. Swelling profiles for a variety of simulations were analyzed and found to include the influence of surface denuded zones, incubation effects, diffusion, swelling-generated stresses and internal temperature shifts. The impact of the latter imposes restrictions on the interpretation of step height measurements and full range intercorrelations for high energy ions

  18. Fundamental aspects of the structural and electrolyte properties of Li2OHCl from simulations and experiment

    Science.gov (United States)

    Howard, Jason; Hood, Zachary D.; Holzwarth, N. A. W.

    2017-12-01

    Solid-state electrolytes that are compatible with high-capacity electrodes are expected to enable the next generation of batteries. As a promising example, Li2OHCl was reported to have good ionic conductivity and to be compatible with a lithium metal anode even at temperatures above 100 ∘C . In this work, we explore the fundamental properties of Li2OHCl by comparing simulations and experiments. Using calculations based on density functional theory, including both static and dynamic contributions through the quasiharmonic approximation, we model a tetragonal ground state, which is not observed experimentally. An ordered orthorhombic low-temperature phase was also simulated, agreeing with experimental structural analysis of the pristine electrolyte at room temperature. In addition, comparison of the ordered structures with simulations of the disordered cubic phase provide insight into the mechanisms associated with the experimentally observed abrupt increase in ionic conductivity as the system changes from its ordered orthorhombic to its disordered cubic phase. A large Haven ratio for the disordered cubic phase is inferred from the computed tracer diffusion coefficient and measured ionic conductivity, suggesting highly correlated motions of the mobile Li ions in the cubic phase of Li2OHCl . We find that the OH bond orientations participate in gating the Li ion motions which might partially explain the predicted Li-Li correlations.

  19. Numerical Simulation Applications in the Design of EGS Collab Experiment 1

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Henry [National Renewable Energy Laboratory (NREL), Golden, CO (United States); White, Mark D. [Pacific Northwest National Laboratory; Fu, Pengcheng [Lawrence Livermore National Laboratory; Ghassemi, Ahmad [University of Oklahoma; Huang, Hai [Idaho National Laboratory; Rutqvist, Jonny [Lawrence Berkeley National Laboratory

    2018-02-14

    The United States Department of Energy, Geothermal Technologies Office (GTO) is funding a collaborative investigation of enhanced geothermal systems (EGS) processes at the meso-scale. This study, referred to as the EGS Collab project, is a unique opportunity for scientists and engineers to investigate the creation of fracture networks and circulation of fluids across those networks under in-situ stress conditions. The EGS Collab project is envisioned to comprise three experiments and the site for the first experiment is on the 4850 Level (4,850 feet below ground surface) in phyllite of the Precambrian Poorman formation, at the Sanford Underground Research Facility, located at the former Homestake Gold Mine, in Lead, South Dakota. Principal objectives of the project are to develop a number of intermediate-scale field sites and to conduct well-controlled in situ experiments focused on rock fracture behavior and permeability enhancement. Data generated during these experiments will be compared against predictions of a suite of computer codes specifically designed to solve problems involving coupled thermal, hydrological, geomechanical, and geochemical processes. Comparisons between experimental and numerical simulation results will provide code developers with direction for improvements and verification of process models, build confidence in the suite of available numerical tools, and ultimately identify critical future development needs for the geothermal modeling community. Moreover, conducting thorough comparisons of models, modelling approaches, measurement approaches and measured data, via the EGS Collab project, will serve to identify techniques that are most likely to succeed at the Frontier Observatory for Research in Geothermal Energy (FORGE), the GTO's flagship EGS research effort. As noted, outcomes from the EGS Collab project experiments will serve as benchmarks for computer code verification, but numerical simulation additionally plays an essential

  20. Studies of an inductively coupled negative hydrogen ion radio frequency source through simulations and experiments

    International Nuclear Information System (INIS)

    Bandyopadhyay, M.

    2004-01-01

    In the frame work of a development project for ITER neutral beam injection system a radio frequency (RF) driven negative hydrogen (H-/D-) ion source, (BATMAN ion source) is developed which is designed to produce several 10s of ampere of H-/D- beam current. This PhD work has been carried out to understand and optimize BATMAN ion source. The study has been done with the help of computer simulations, modeling and experiments. The complete three dimensional Monte-Carlo computer simulation codes have been developed under the scope of this PhD work. A comprehensive description about the volume production and the surface production of H- ions is presented in the thesis along with the study results obtained from the simulations, modeling and the experiments. One of the simulations is based on the volume production of H- ions, where it calculates the density profile of the vibrationally excited H2 molecules, the density profile of H- ions and the transport probability of those H- ions along the source axis towards the grid. The other simulation studies the transport of those H- ions which are produced on the surface of the plasma grid. It is expected that if there is a plasma flow in the source, the transport of plasma components (molecules and ions) would be influenced. Experimentally it is observed that there is a convective plasma flow exists in the ion source. A transverse magnetic filter field which is present near the grid inside the ion source reduces the flow velocity. Negative ions and electrons have the same sign of charge; therefore the electrons are co-extracted with the negative ions through the grid system, which is not desirable. It is observed that a magnetic field near the grid, magnetized the electrons and therefore reduce the co-extracted electron current. It is also observed experimentally that if the plasma grid is biased positively with respect to the source body, the electron density near the plasma grid is reduced and therefore the co

  1. Studies of an inductively coupled negative hydrogen ion radio frequency source through simulations and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, M.

    2004-08-24

    In the frame work of a development project for ITER neutral beam injection system a radio frequency (RF) driven negative hydrogen (H-/D-) ion source, (BATMAN ion source) is developed which is designed to produce several 10s of ampere of H-/D- beam current. This PhD work has been carried out to understand and optimize BATMAN ion source. The study has been done with the help of computer simulations, modeling and experiments. The complete three dimensional Monte-Carlo computer simulation codes have been developed under the scope of this PhD work. A comprehensive description about the volume production and the surface production of H- ions is presented in the thesis along with the study results obtained from the simulations, modeling and the experiments. One of the simulations is based on the volume production of H- ions, where it calculates the density profile of the vibrationally excited H2 molecules, the density profile of H- ions and the transport probability of those H- ions along the source axis towards the grid. The other simulation studies the transport of those H- ions which are produced on the surface of the plasma grid. It is expected that if there is a plasma flow in the source, the transport of plasma components (molecules and ions) would be influenced. Experimentally it is observed that there is a convective plasma flow exists in the ion source. A transverse magnetic filter field which is present near the grid inside the ion source reduces the flow velocity. Negative ions and electrons have the same sign of charge; therefore the electrons are co-extracted with the negative ions through the grid system, which is not desirable. It is observed that a magnetic field near the grid, magnetized the electrons and therefore reduce the co-extracted electron current. It is also observed experimentally that if the plasma grid is biased positively with respect to the source body, the electron density near the plasma grid is reduced and therefore the co

  2. [Experiment and numerical simulation of percolation control using evapotranspirative landfill cover system].

    Science.gov (United States)

    Liu, Chuan-shun; Zhao, Hui; Luo, Ji-wu

    2009-01-01

    An Evapotranspirative Landfill Cover (ET Landfill Cover) is a simple and economical percolation control system that involves a monolithic soil layer with a vegetative cover.Percolation control in an ET cover system relies on the storage of moisture within the cover soils during precipitation events and subsequently returns it to the atmosphere by evapotranspiration. Percolation control experiments of a bare soil cover and 5 different ET covers were implemented in comprehensive experimental station of water environment of Wuhan University and the water balance calculation of each cover system was conducted, the results shown that the ET cover of 60 cm loamy soil layer with shrub was the most effective among the 6 experimental disposals. However, the experiments demonstrated 60 cm thick of soil layer was not enough to prevent percolation during rainy season and keep the shrub alive during drought season without irrigation. So the Hydrus 2D was selected to simulate the soil water movement in ET covers with different cover thicknesses, the simulations shown that the optimal ET cover in Wuhan area should be 120-140 cm loamy soil layer with shrub.

  3. Local mechanical properties of LFT injection molded parts: Numerical simulations versus experiments

    Science.gov (United States)

    Desplentere, F.; Soete, K.; Bonte, H.; Debrabandere, E.

    2014-05-01

    In predictive engineering for polymer processes, the proper prediction of material microstructure from known processing conditions and constituent material properties is a critical step forward properly predicting bulk properties in the finished composite. Operating within the context of long-fiber thermoplastics (LFT, length fiber breakage algorithm for the polymer flow inside the mold is available. Using well known micro mechanic formulas allow to combine the local fiber length with the local orientation into local mechanical properties. Different experiments were performed using a commercially available glass fiber filled compound to compare the measured data with the numerical simulation results. In this investigation, tensile tests and 3 point bending tests are considered. To characterize the fiber length distribution of the polymer melt entering the mold (necessary for the numerical simulations), air shots were performed. For those air shots, similar homogenization conditions were used as during the injection molding tests. The fiber length distribution is characterized using automated optical method on samples for which the matrix material is burned away. Using the appropriate settings for the different experiments, good predictions of the local mechanical properties are obtained.

  4. The impact of delivery style on doctors' experience of stress during simulated bad news consultations.

    Science.gov (United States)

    Shaw, Joanne; Brown, Rhonda; Dunn, Stewart

    2015-10-01

    The purpose of this study was to investigate the relationship between doctors' bad news delivery style and their experience of physiological stress during simulated bad news consultations. 31 doctors participated in two simulated breaking bad news (BBN) consultations. Delivery style was categorized as either blunt, forecasting or stalling (i.e. avoidant), based on the time to deliver the bad news and qualitative analysis of the interaction content and doctor's language style. Doctors' heart rate (HR) and skin conductance (SC) were recorded in consecutive 30s epochs. Doctors experienced a significant decrease in HR (F(1,36)=44.9, pnews delivery phases of the consultation. Between-group comparisons for the three delivery styles did not identify any significant differences in HR (F(2,36)=2.2, p>.05) or SC (F(2,48)=.66, p>.05). Doctors experience heightened stress in the pre-news delivery phase of breaking bad news interactions. Delaying the delivery of bad news exposes doctors to a longer period of increased stress.This suggests that medical students and doctors should be taught to deliver bad news without delay, to help mitigate their response to this stressful encounter. Copyright © 2015. Published by Elsevier Ireland Ltd.

  5. Benefits and Pitfalls of Using HTML5 APIs for Online Experiments and Simulations

    Directory of Open Access Journals (Sweden)

    Pablo Garaizar

    2012-11-01

    Full Text Available The most recent advances in the architecture of the Web allow using it as an excellent platform to deliver experiments and simulations over the Internet. However, there are still some challenges related to the animations’ accuracy, to user input collection or to real-time communications that have to be accomplished to properly port native application- based experiments and simulations to the Web. The limitations of the standards preceding HTML5 have forced web developers to embed non-HTML objects using a wide range of non-standard plugins and causing an extremely fragmented execution environment where features must be implemented several times in different programming languages to guarantee full compliance with every user-agent. As HTML5 provides a standard -yet fully-featured- environment to develop and execute applications, web user-agents are now more similar to application players than to simple Internet browsers. In this paper we analyze the benefits and pitfalls of these new Application Programming Interfaces (APIs, providing examples of both good and bad instances of research-related use.

  6. The voltage-current characteristic of high-T C DC SQUID: Theory, simulation, experiment

    International Nuclear Information System (INIS)

    Greenberg, Ya.S.; Novikov, I.L.

    2006-01-01

    The analytical theory for the voltage-current characteristics of the large inductance (L > 100 pH) high-T C DC SQUIDs that has been developed previously is consistently compared with the computer simulations and the experiment. The theoretical voltage modulation for symmetric junctions is shown to be in a good agreement with the results of known computer simulations. It is shown that the asymmetry of the junctions results in the increase of the voltage modulation if the critical current is in excess of some threshold value (about 8 μA). Below this value the asymmetry leads to the reduction of the voltage modulation as compared to the symmetric case. The comparison with the experiment shows that the asymmetry can explain a large portion of experimental values of the voltage modulation which lie above the theoretical curve for symmetric DC SQUID. It also explains experimental points which lie below the curve at low critical currents. However, a significant portion of these values which lie below the curve cannot be explained by the junction asymmetry

  7. Enviromental behavior of sulfentrazone and fipronil in a Brazilian clayey latosol: field experiment and simulation

    Directory of Open Access Journals (Sweden)

    Rômulo Penna Scorza Júnior

    2014-10-01

    Full Text Available There has been an urgent need to assess pesticide environmental behavior under Brazilian field conditions and to evaluate the risks associated to its use in agriculture. Besides a qualitative and quantitative interpretation of field experiments to acquire understanding about pesticide environmental behaviour, field experiments are important to test pesticide fate models. Environmental behaviour of fipronil and sulfentrazone in a sugarcane area in Dourados, MS, was evaluated until 257 days after application. Moreover, the PEARL model was tested to simulate the fate of these two pesticides in the field. Soil samples for pesticide residue quantification and water content were taken at 0-10, 10-30, 30-50, 50-70 and 70-100 cm depth. There was a fast dissipation of both pesticides at soil surface within 15 days after application and their leaching was not beyond 30 cm depth. Dissipation and leaching satisfactory simulations for both pesticides were achieved only after calibration of half-life values or using a reduced initial dose. This study shows that fast dissipation of pesticides in the field can be an important process to consider when assessing the environmental behavior of pesticides in Brazil.

  8. Chaotic advection at large Péclet number: Electromagnetically driven experiments, numerical simulations, and theoretical predictions

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, Aldo [Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos 62209 (Mexico); Meunier, Patrice; Villermaux, Emmanuel [Aix-Marseille Univ., CNRS, Centrale Marseille, IRPHE, Marseille F-13384 (France); Cuevas, Sergio; Ramos, Eduardo [Instituto de Energías Renovables, Universidad Nacional Autónoma de México, A.P. 34, Temixco, Morelos 62580 (Mexico)

    2014-01-15

    We present a combination of experiment, theory, and modelling on laminar mixing at large Péclet number. The flow is produced by oscillating electromagnetic forces in a thin electrolytic fluid layer, leading to oscillating dipoles, quadrupoles, octopoles, and disordered flows. The numerical simulations are based on the Diffusive Strip Method (DSM) which was recently introduced (P. Meunier and E. Villermaux, “The diffusive strip method for scalar mixing in two-dimensions,” J. Fluid Mech. 662, 134–172 (2010)) to solve the advection-diffusion problem by combining Lagrangian techniques and theoretical modelling of the diffusion. Numerical simulations obtained with the DSM are in reasonable agreement with quantitative dye visualization experiments of the scalar fields. A theoretical model based on log-normal Probability Density Functions (PDFs) of stretching factors, characteristic of homogeneous turbulence in the Batchelor regime, allows to predict the PDFs of scalar in agreement with numerical and experimental results. This model also indicates that the PDFs of scalar are asymptotically close to log-normal at late stages, except for the large concentration levels which correspond to low stretching factors.

  9. Simulation, realization and test of veto systems for the NA62 experiment

    CERN Document Server

    Palladino, Vito

    Search Simple Search Advanced Search Latest Additions Browse Browse by Author Browse by Subject Browse by Year Browse by Type Browse by Full text availability Info Policy About FAQ Contact us Palladino, Vito (2010) Simulation, realization and test of veto systems for the NA62 experiment. [Tesi di dottorato] (Unpublished) [img] PDF palladino_vito_23.pdf Download (55MB) | Preview Item Type: Tesi di dottorato Language: English Title: Simulation, realization and test of veto systems for the NA62 experiment Creators: Creators\tEmail Palladino, Vito\tvitopalladino@gmail.com Date: 30 November 2010 Number of Pages: 146 Institution: Università degli Studi di Napoli Federico II Department: Scienze fisiche Doctoral School: Scienze fisiche PHD name: Fisica fondamentale ed applicata PHD cycle: 23 PHD Coordinator: name\temail Marrucci, Lorenzo\tUNSPECIFIED Tutor: name\temail Ambrosino, Fabio\tUNSPECIFIED Date: 30 November 2010 Number of Pages: 146 Uncontrolled Keywords: Kaon NA62 Veto CHANTI LAV MIUR S.S.D...

  10. Construction of Spectral Discoloration Model for Red Lead Pigment by Aging Test and Simulating Degradation Experiment

    Directory of Open Access Journals (Sweden)

    Jinxing Liang

    2016-01-01

    Full Text Available The construction of spectral discoloration model, based on aging test and simulating degradation experiment, was proposed to detect the aging degree of red lead pigment in ancient murals and to reproduce the spectral data supporting digital restoration of the ancient murals. The degradation process of red lead pigment under the aging test conditions was revealed by X-ray diffraction, scanning electron microscopy, and spectrophotometer. The simulating degradation experiment was carried out by proportionally mixing red lead and lead dioxide with referring to the results of aging test. The experimental result indicated that the pure red lead was gradually turned into black lead dioxide, and the amount of tiny particles of the aging sample increased faced with aging process. Both the chroma and lightness of red lead pigment decreased with discoloration, and its hue essentially remains unchanged. In addition, the spectral reflectance curves of the aging samples almost started rising at about 550 nm with the inflection moving slightly from about 570 nm to 550 nm. The spectral reflectance of samples in long- and in short-wavelength regions was fitted well with the logarithmic and linear function. The spectral discoloration model was established, and the real aging red lead pigment in Dunhuang murals was measured and verified the effectiveness of the model.

  11. Numerical simulation of MH growth/dissociation by hot water injection on the Lab. experiment

    Science.gov (United States)

    Temma, N.; Sakamoto, Y.; Komai, T.; Yamaguchi, T.; Pawar, R.; Zyvoloski, G.

    2005-12-01

    Methane Hydrate (MH) is considered to be one of the new-generation energy resources. Aiming to develop the method of extraction of methane gas from MH, laboratory experiments have been performed in order to grasp the MH property in the National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba in Japan. In this paper, we present the results of the numerical simulation of experiment using by the hot water injection. In this calculation, FEHM (Finite Element Heat and Mass transfer) code is used. This code is developed at Los Alamos National Laboratory. In this experiment, temperature, pressure and cumulative gas production were measured. From these data, we suppose that MH growth/dissociation occurred by the flow of the hot water. And we make the model of the growth/dissociation. As this model consist of many parameters, it is difficult to determine parameters. Thus, we use PEST (Parameter ESTimation ) in order to determine parameters for the model of the MH growth/ dissociation. We use temperature data of experiment, as observed data. We make two observed data sets at the beginning and later term of experiment. At the results of PEST, we obtain two sets of parameters to get good match the observed data. We think that these sets indicate both the maximum and the minimum values of the MH growth/dissociation model. And, on this range, we continue to calculate until we get the good match. Finally, we obtain the numerical model of the experiment. Also, we conducted the sensitive analysis for the MH growth/ dissociation using this model.

  12. Faculty and Student Perceptions of Preparation for and Implementation of High Fidelity Simulation Experiences in Associate Degree Nursing Programs

    Science.gov (United States)

    Conejo, Patricia E.

    2010-01-01

    High fidelity simulation technology is being used as an alternative way to expose students to complex patient care. Research has shown that simulation experiences can improve critical thinking skills and increase students' self-confidence (Jeffries & Rizzolo, 2006). The purpose of this study was to examine nurse educator and nursing student…

  13. The role of simulations in consumer experiences and behavior: insights from the grounded cognition theory of desire

    OpenAIRE

    Papies, Esther K.; Best, Maisy; Gelibter, Elena; Barsalou, Lawrence W.

    2017-01-01

    What are the mechanisms by which extrinsic and environmental cues affect consumer experiences, desires, and choices? Based on the recent grounded cognition theory of desire, we argue that consumption and reward simulations constitute a central mechanism in these phenomena. Specifically, we argue that appetitive stimuli, such as specific product cues, can activate simulations of consuming and enjoying the respective products, based on previous learning experiences. These consumption and reward...

  14. Hydrodynamic simulations of integrated experiments planned for OMEGA/OMEGA EP laser systems

    International Nuclear Information System (INIS)

    Delettrez, J. A.; Myatt, J.; Radha, P. B.; Stoeckl, C.; Meyerhofer, D. D.

    2005-01-01

    Integrated fast-ignition experiments for the combined OMEGA/OMEGA EP laser systems have been simulated with the multidimensional hydrodynamic code DRACO. In the simplified electron transport model included in DRACO, the electrons are introduced at the pole of a 2-D simulation and transported in a straight line toward the target core, depositing their energy according to a recently published slowing-down formula.1 Simulations, including alpha transport, of an OMEGA cryogenic target designed to reach a 1-D fuel R of 500 mg/cm2 have been carried out for 1-D (clean) and, more realistic, 2-D (with nonuniformities) implosions to assess the sensitivity to energy, timing, and irradiance of the Gaussian fast-ignitor beam. The OMEGA laser system provides up to 30 kJ of compression energy, and OMEGA EP will provide two short pulse beams, each with energies up to 2.6 kJ. For the 1-D case, the neutron yield is predicted to be in excess of 1015 (compared to 1014 for no ignitor beam) over a timing range of about 80 ps. This talk will present these results and new 2-D simulation results that include the effects of realistic cryogenic target perturbations on the compressed core. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460, the University of Rochester, and the New York State Energy Research and Development Authority. The support of DOE does not constitute an endorsement by DOE of the views expressed in this article. (Author)

  15. Simulating Arctic clouds during Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE)

    Science.gov (United States)

    Bromwich, D. H.; Hines, K. M.; Wang, S. H.

    2015-12-01

    The representation within global and regional models of the extensive low-level cloud cover over polar oceans remains a critical challenge for quantitative studies and forecasts of polar climate. In response, the polar-optimized version of the Weather Research and Forecasting model (Polar WRF) is used to simulate the meteorology, boundary layer, and Arctic clouds during the September-October 2014 Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE) project. Polar WRF was developed with several adjustments to the sea ice thermodynamics in WRF. ARISE was based out of Eielson Air Force Base near Fairbanks, Alaska and included multiple instrumented C-130 aircraft flights over open water and sea ice of the Beaufort Sea. Arctic boundary layer clouds were frequently observed within cold northeasterly flow over the open ocean and ice. Preliminary results indicate these clouds were primarily liquid water, with characteristics differing between open water and sea ice surfaces. Simulated clouds are compared to ARISE observations. Furthermore, Polar WRF simulations are run for the August-September 2008 Arctic Summer Cloud Ocean Study (ASCOS) for comparison to the ARISE. Preliminary analysis shows that simulated low-level water clouds over the sea ice are too extensive during the the second half of the ASCOS field program. Alternatives and improvements to the Polar WRF cloud schemes are considered. The goal is to use the ARISE and ASCOS observations to achieve an improved polar supplement to the WRF code for open water and sea ice that can be provided to the Polar WRF community.

  16. Experiment and numerical simulation of welding induced damage: stainless steel 15-5PH

    Energy Technology Data Exchange (ETDEWEB)

    Wu, T

    2007-11-15

    The objective of this study is the prediction of damage and residual stresses induced by hot processing which leads to phase transformation in martensitic stainless steel. This study firstly concerns the modelling of the damage of material induced by a complex history of thermo-elastoplastic multiphase in heat-affected-zone (HAZ) of welding. In this work, a two-scale mode of elastoplastic damage multiphase was developed in the framework of thermodynamics of irreversible process. The constitutive equations are coupling with ductile damage, elasto-plasticity, phase transformation, and transformation plasticity. Besides, a damage equation was proposed based on the Lemaitre's damage model in the framework of continuum damage mechanics. The experiments of 15-5PH were implemented for the identification of phase transformation, transformation plasticity and damage models. Tensile tests of round specimens were used to identify the parameters of damage model as well as mechanical behaviours at various temperatures. Tests of flat notched specimen were designed to provide the validation of damage model and strain localization using three dimensional image correlation technologies. In addition, microscopic analysis was performed to provide microstructure characterization of 15-5PH and to discover the damage mechanism. Finally the numerical simulation was performed in the code CAST3M of CEA. On the one hand, numerical verification of the flat notched plates was implemented and compared with experimental results. On the other hand, we used the two-scale model including phase transformation, transformation plasticity and damage to simulate the level of residual stresses of a disk made of 15-5PH metal heated by laser. The internal variables, such as strain, stress, damage, were successfully traced in the simulation of two-scale model. The simulation results showed the transformation plasticity changes the level of residual stresses and should not be negligible; damage

  17. Experiment and numerical simulation of welding induced damage: stainless steel 15-5PH

    International Nuclear Information System (INIS)

    Wu, T.

    2007-11-01

    The objective of this study is the prediction of damage and residual stresses induced by hot processing which leads to phase transformation in martensitic stainless steel. This study firstly concerns the modelling of the damage of material induced by a complex history of thermo-elastoplastic multiphase in heat-affected-zone (HAZ) of welding. In this work, a two-scale mode of elastoplastic damage multiphase was developed in the framework of thermodynamics of irreversible process. The constitutive equations are coupling with ductile damage, elasto-plasticity, phase transformation, and transformation plasticity. Besides, a damage equation was proposed based on the Lemaitre's damage model in the framework of continuum damage mechanics. The experiments of 15-5PH were implemented for the identification of phase transformation, transformation plasticity and damage models. Tensile tests of round specimens were used to identify the parameters of damage model as well as mechanical behaviours at various temperatures. Tests of flat notched specimen were designed to provide the validation of damage model and strain localization using three dimensional image correlation technologies. In addition, microscopic analysis was performed to provide microstructure characterization of 15-5PH and to discover the damage mechanism. Finally the numerical simulation was performed in the code CAST3M of CEA. On the one hand, numerical verification of the flat notched plates was implemented and compared with experimental results. On the other hand, we used the two-scale model including phase transformation, transformation plasticity and damage to simulate the level of residual stresses of a disk made of 15-5PH metal heated by laser. The internal variables, such as strain, stress, damage, were successfully traced in the simulation of two-scale model. The simulation results showed the transformation plasticity changes the level of residual stresses and should not be negligible; damage decreases

  18. Monte-Carlo method simulation of the Bremsstrahlung mirror reflection experiment

    International Nuclear Information System (INIS)

    Aliev, F.K.; Muminov, A.T.; Skvortsov, V.V.; Osmanov, B.S.

    2004-01-01

    Full text: To detect gamma-ray mirror reflection on macroscopic smooth surface a search experiment at microtron MT-22S with 330 meter flying distance is in progress. Measured slip angles (i.e. angles between incident ray and reflector surface) don't exceed tens of micro-radian. Under such angles an effect of the reflection could be easily veiled due to negative background conditions. That is why the process needed to be simulated by Monte-Carlo method as accurate as possible and corresponding computer program was developed. A first operating mode of the MT-22S generates 13 MeV electrons that are incident on a Bremsstrahlung target. So energies of gamma-rays were simulated to be in the range of 0.01†12.5 MeV and be distributed by known Shift formula. When any gamma-quantum was incident on the reflector it resulted in following two cases. If its slip angle was more than the critical one, gamma-quantum was to be absorbed by the reflector and the program started to simulate next event. In the other case the program replaced incident gamma-quantum trajectory parameters by the reflected ones. The gamma-quantum trajectory behind the reflector was traced till its detector. Any gamma-quantum that got the detector was to be registered. As any simulated gamma-quantum was of random energy the critical slip angle of every simulated event was evaluated by the following formula: α crit = eh/E √ZN A ρ/πAm. Table values of the absorption coefficients were used for random simulation of gamma-quanta absorption in the air. And it was assumed that any gamma-quantum interaction with air resulted in its disappearance. Dependence of different flying distances (120 and 330 m), gap heights (10, 20 and 50 μ) of the gap collimator and inclinations (20 and 40 μrad) of the reflector's plane on detected gamma-quanta energy distribution and vertical angle one was studied with a help of the developed program

  19. Simulation of complete neutron scattering experiments: from model systems to liquid germanium; Simulation complete d'une experience de diffusion de neutrons: des systemes modeles au germanium liquide

    Energy Technology Data Exchange (ETDEWEB)

    Hugouvieux, V

    2004-11-15

    In this thesis, both theoretical and experimental studies of liquids are done. Neutron scattering enables structural and dynamical properties of liquids to be investigated. On the theoretical side, molecular dynamics simulations are of great interest since they give positions and velocities of the atoms and the forces acting on each of them. They also enable spatial and temporal correlations to be computed and these quantities are also available from neutron scattering experiments. Consequently, the comparison can be made between results from molecular dynamics simulations and from neutron scattering experiments, in order to improve our understanding of the structure and dynamics of liquids. However, since extracting reliable data from a neutron scattering experiment is difficult, we propose to simulate the experiment as a whole, including both instrument and sample, in order to gain understanding and to evaluate the impact of the different parasitic contributions (absorption, multiple scattering associated with elastic and inelastic scattering, instrument resolution). This approach, in which the sample is described by its structure and dynamics as computed from molecular dynamics simulations, is presented and tested on isotropic model systems. Then liquid germanium is investigated by inelastic neutron scattering and both classical and ab initio molecular dynamics simulations. This enables us to simulate the experiment we performed and to evaluate the influence of the contributions from the instrument and from the sample on the detected signal. (author)

  20. Task experience influences coordinative structures and performance variables in learning a slalom ski-simulator task.

    Science.gov (United States)

    Dutt-Mazumder, A; Newell, K M

    2018-01-29

    The experiment investigated the progressions of the qualitative and quantitative changes in the movement dynamics of learning the ski-simulator as a function of prior-related task experience. The focus was the differential timescales of change in the candidate collective variable, neuromuscular synergies, joint motions, and task outcome as a function of learning over 7 days of practice. Half of the novice participants revealed in day 1 a transition of in-phase to anti-phase coupling of center of mass (CoM)-platform motion whereas the remaining novices and experienced group all produced on the first trial an anti-phase CoM-platform coupling. The experienced group also had initially greater amplitude and velocity of platform motion-a performance advantage over the novice group that was reduced but not eliminated with 7 days of practice. The novice participants who had an in-phase CoM-platform coupling on the initial trials of day 1 also showed the most restricted platform motion in those trials. Prior-related practice experience differentially influenced the learning of the task as evidenced by both the qualitative organization and the quantitative motion properties of the individual degrees of freedom (dof) to meet the task demands. The findings provide further evidence to the proposition that CoM-platform coupling is a candidate collective variable in the ski-simulator task that provides organization and boundary conditions to the motions of the individual joint dof and their couplings. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Transmission experiment by the simulated LMFBR model and propagation analysis of acoustic signals

    International Nuclear Information System (INIS)

    Kobayashi, Kenji; Yasuda, Tsutomu; Araki, Hitoshi.

    1981-01-01

    Acoustic transducers to detect a boiling of sodium may be installed in the upper structure and at the upper position of reactor vessel wall under constricted conditions. A set of the experiments of transmission of acoustic vibration to various points of the vessel was performed utilizing the half scale-hydraulic flow test facility simulating reactor vessel over the frequency range 20 kHz -- 100 kHz. Acoustic signals from an installed sound source in the core were measured at each point by both hydrophones in the vessel and vibration pickups on the vessel wall. In these experiments transmission of signals to each point of detectors were clearly observed to background noise level. These data have been summarized in terms of the transmission loss and furthermore are compared with background noise level of flow to estimate the feasibility of detection of sodium boiling sound. The ratio of signal to noise was obtained to be about 13 dB by hydrophone in the upper structure, 8 dB by accelerometer and 16 dB by AE-sensor at the upper position on the vessel in experiments used the simulation model. Sound waves emanated due to sodium boiling also propagate along the wall of the vessel may be predicted theoretically. The result of analysis suggests a capability of detection at the upper position of the reactor vessel wall. Leaky Lamb waves of the first symmetric (L 1 ) and of the antisymmetric (F 1 ) mode and shear horizontal wave (SH) have been derived in light of the attenuation due to coupling to liquid sodium as the traveling modes over the frequency range 10 kHz -- 100 kHz up to 50 mm in thickness of the vessel wall. Leaky Lamb wave (L 1 ) and (SH) mode have been proposed theoretically on the some assumption to be most available to detect the boiling sound of sodium propagating along the vessel wall. (author)

  2. Simulation Analysis and Experiment of Variable-Displacement Asymmetric Axial Piston Pump

    Directory of Open Access Journals (Sweden)

    Youshan Gao

    2017-03-01

    Full Text Available The variable displacement pump control system has greater energy-saving advantages and application prospects than the valve control system. However, the variable displacement pump control of differential cylinder is not concurrent with the existing technologies. The asymmetric pump-controlled cylinder is, therefore, used to balance the unequal volume flow through a single rod cylinder in closed-circuit system. This is considered to be an effective method. Nevertheless, the asymmetric axial piston pump (AAPP is a constant displacement pump. In this study, variable-displacement asymmetric axial piston pump (VAPP is investigated according to the same principle used in investigating AAPP. This study, therefore, aims at investigating the characteristics of VAPP. The variable-displacement output of VAPP is implemented by controlling the swash plate angle with angle feedback control circuit, which is composed of a servo proportional valve and an angular displacement sensor. The angular displacement sensor is connected to the swash plate. The simulation model of VAPP, which is set up through the ITI-SimulationX simulation platform, is used to predict VAPP’s characteristics. The purpose of implementing the experiment is to verify the theoretical results. Both the simulation and the experiment results demonstrated that the swash plate angle is controlled by a variable mechanism; when the swash plate angle increases, the flow of Port B and Port T increases while the response speed of Port B and Port T also accelerates. When the swash plate angle is constant, the flow of Port B and Port T increases along with the increase of pump speed, although the pressure-response speed of Port B is faster than that of Port T. Consequently, the flow pulsation of Port B and Port T tends to decrease gradually along with the increase of pump speed. When the pressure loaded on Port B equals to that of Port T, the flow ripple cycle of Port B is longer than that of Port T

  3. Turbulent Dynamo Amplification of Magnetic Fields in Laser-Produced Plasmas: Simulations and Experiments

    Science.gov (United States)

    Tzeferacos, P.; Rigby, A.; Bott, A.; Bell, A.; Bingham, R.; Casner, A.; Cattaneo, F.; Churazov, E.; Forest, C.; Katz, J.; Koenig, M.; Li, C.-K.; Meinecke, J.; Petrasso, R.; Park, H.-S.; Remington, B.; Ross, J.; Ryutov, D.; Ryu, D.; Reville, B.; Miniati, F.; Schekochihin, A.; Froula, D.; Lamb, D.; Gregori, G.

    2017-10-01

    The universe is permeated by magnetic fields, with strengths ranging from a femtogauss in the voids between the filaments of galaxy clusters to several teragauss in black holes and neutron stars. The standard model for cosmological magnetic fields is the nonlinear amplification of seed fields via turbulent dynamo. We have conceived experiments to demonstrate and study the turbulent dynamo mechanism in the laboratory. Here, we describe the design of these experiments through large-scale 3D FLASH simulations on the Mira supercomputer at ANL, and the laser-driven experiments we conducted with the OMEGA laser at LLE. Our results indicate that turbulence is capable of rapidly amplifying seed fields to near equipartition with the turbulent fluid motions. This work was supported in part from the ERC (FP7/2007-2013, No. 256973 and 247039), and the U.S. DOE, Contract No. B591485 to LLNL, FWP 57789 to ANL, Grant No. DE-NA0002724 and DE-SC0016566 to the University of Chicago, and DE-AC02-06CH11357 to ANL.

  4. Modeling and simulations of radiative blast wave driven Rayleigh-Taylor instability experiments

    Science.gov (United States)

    Shimony, Assaf; Huntington, Channing M.; Trantham, Matthew; Malamud, Guy; Elbaz, Yonatan; Kuranz, Carolyn C.; Drake, R. Paul; Shvarts, Dov

    2017-10-01

    Recent experiments at the National Ignition Facility measured the growth of Rayleigh-Taylor RT instabilities driven by radiative blast waves, relevant to astrophysics and other HEDP systems. We constructed a new Buoyancy-Drag (BD) model, which accounts for the ablation effect on both bubble and spike. This ablation effect is accounted for by using the potential flow model ]Oron et al PoP 1998], adding another term to the classical BD formalism: βDuA / u , where β the Takabe constant, D the drag term, uA the ablation velocity and uthe instability growth velocity. The model results are compared with the results of experiments and 2D simulations using the CRASH code, with nominal radiation or reduced foam opacity (by a factor of 1000). The ablation constant of the model, βb / s, for the bubble and for the spike fronts, are calibrated using the results of the radiative shock experiments. This work is funded by the Lawrence Livermore National Laboratory under subcontract B614207, and was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  5. Experiments and simulations studying electrothermal instabilities in magnetically accelerated implosion systems

    Science.gov (United States)

    Peterson, Kyle

    2012-10-01

    Electrothermal instabilities in electrical conductors can occur whenever the electrical conductivity depends on temperature. Of particular interest are electrothermal instabilities that occur when the electrical conductivity decreases with temperature, which is the case in most metals until they are heated into a Spitzer-like conductivity regime. These instabilities form stratified structures perpendicular to the current flow that are similar in appearance to m=0 sausage type instabilities and can geometrically couple to magneto-Rayleigh-Taylor (MRT) instabilities as the system is accelerated. Several experiments were performed using the 100-ns Z accelerator that drove up to 20 MA through well-characterized, initially solid and smooth (<50 nm RMS) Al and Cu rods. The experiments used 2-frame (6151 eV) or 2-color (1865/6151 eV) monochromatic x-ray backlighting to image instability growth on the surface of the rods. Excellent agreement is obtained between measurements and simulations that show the majority of the instability growth occurs immediately after the surface of the rod melts and is in regions that are stable to MRT instabilities and unstable to electrothermal instabilities. We will also show how MRT instability theory alone cannot explain the levels of instability growth observed in experiments.

  6. Numerical simulations of the flow with the prescribed displacement of the airfoil and comparison with experiment

    Science.gov (United States)

    Řidký, V.; Šidlof, P.; Vlček, V.

    2013-04-01

    The work is devoted to comparing measured data with the results of numerical simulations. As mathematical model was used mathematical model whitout turbulence for incompressible flow In the experiment was observed the behavior of designed NACA0015 airfoil in airflow. For the numerical solution was used OpenFOAM computational package, this is open-source software based on finite volume method. In the numerical solution is prescribed displacement of the airfoil, which corresponds to the experiment. The velocity at a point close to the airfoil surface is compared with the experimental data obtained from interferographic measurements of the velocity field. Numerical solution is computed on a 3D mesh composed of about 1 million ortogonal hexahedron elements. The time step is limited by the Courant number. Parallel computations are run on supercomputers of the CIV at Technical University in Prague (HAL and FOX) and on a computer cluster of the Faculty of Mechatronics of Liberec (HYDRA). Run time is fixed at five periods, the results from the fifth periods and average value for all periods are then be compared with experiment.

  7. Performance experiments with alternative advanced teleoperator control modes for a simulated solar maximum satellite repair

    Science.gov (United States)

    Das, H.; Zak, H.; Kim, W. S.; Bejczy, A. K.; Schenker, P. S.

    1992-01-01

    Experiments are described which were conducted at the JPL Advanced Teleoperator Lab to demonstrate and evaluate the effectiveness of various teleoperator control modes in the performance of a simulated Solar Max Satellite Repair (SMSR) task. THe SMSR was selected as a test because it is very rich in performance capability requirements and it actually has been performed by two EVA astronauts in the Space Shuttle Bay in 1984. The main subtasks are: thermal blanket removal; installation of a hinge attachment for electrical panel opening; opening of electrical panel; removal of electrical connectors; relining of cable bundles; replacement of electrical panel; securing parts and cables; re-mate electrical connectors; closing of electrical panel; and reinstating thermal blanket. The current performance experiments are limited to thermal blanket cutting, electrical panel unbolting and handling electrical bundles and connectors. In one formal experiment even different control modes were applied to the unbolting and reinsertion of electrical panel screws subtasks. The seven control modes are alternative combinations of manual position and rate control with force feedback and remote compliance referenced to force-torque sensor information. Force-torque sensor and end effector position data and task completion times were recorded for analysis and quantification of operator performance.

  8. Apollo experience report: A use of network simulation techniques in the design of the Apollo lunar surface experiments package support system

    Science.gov (United States)

    Gustafson, R. A.; Wilkes, J. N.

    1974-01-01

    A case study of data-communications network modeling and simulation is presented. The applicability of simulation techniques in early system design phases is demonstrated, and the ease with which model parameters can be changed and comprehensive statistics gathered is shown. The discussion of the model design and application also yields an insight into the design and implementation of the Apollo lunar surface experiments package ground-support system.

  9. Snapshots of simulation: creative strategies used by Australian educators to enhance simulation learning experiences for nursing students.

    Science.gov (United States)

    McAllister, Margaret; Levett-Jones, Tracy; Downer, Teresa; Harrison, Penelope; Harvey, Theresa; Reid-Searl, Kerry; Lynch, Kathy; Arthur, Carol; Layh, Janice; Calleja, Pauline

    2013-11-01

    Simulation in nursing is a flourishing area for nurse educators' practice. Defined as learning that amplifies, mimics or replaces real-life clinical situations, simulation aims to give students opportunity to reason through a clinical problem and make decisions, without the potential for harming actual patients. Educators in nursing are contributing to simulation learning in diverse and creative ways. Yet much of their craft is not being widely disseminated because educators are not always confident in publishing their work. This paper aims to stimulate creative development in simulation by providing short summaries, or snapshots, of diverse approaches that nurse educators are using. The objective is to inspire others to share other ideas in development or in practice that are improving learning for nursing students and practitioners, so that simulation scholarship is advanced. The snapshots presented range from approaches that: better support educators to attend to the whole process of simulation education, give students quick access to short skill-based videos, orientate students to the laboratory environment, harness the power of the group to develop documentation skills, use simulation to enrich lectures, develop multidisciplinary knowledge, and finally, which teach therapeutic communication with children in a fun and imaginative way. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. High-Fidelity Simulation of Pediatric Emergency Care: An Eye-Opening Experience for Baccalaureate Nursing Students.

    Science.gov (United States)

    Small, Sandra P; Colbourne, Peggy A; Murray, Cynthia L

    2018-01-01

    Background Little attention has been given to in-depth examination of what high-fidelity simulation is like for nursing students within the context of a pediatric emergency, such as a cardiopulmonary arrest. It is possible that such high-fidelity simulation could provoke in nursing students intense psychological reactions. Purpose The purpose of this study was to learn about baccalaureate nursing students' lived experience of high-fidelity simulation of pediatric cardiopulmonary arrest. Method Phenomenological methods were used. Twenty-four interviews were conducted with 12 students and were analyzed for themes. Results The essence of the experience is that it was eye-opening. The students found the simulation to be a surprisingly realistic nursing experience as reflected in their perceiving the manikin as a real patient, thinking that they were saving their patient's life, feeling like a real nurse, and feeling relief after mounting stress. It was a surprisingly valuable learning experience in that the students had an increased awareness of the art and science of nursing and increased understanding of the importance of teamwork and were feeling more prepared for clinical practice and wanting more simulation experiences. Conclusion Educators should capitalize on the benefits of high-fidelity simulation as a pedagogy, while endeavoring to provide psychologically safe learning.

  11. Radiation disaster response: preparation and simulation experience at an academic medical center.

    Science.gov (United States)

    Schleipman, A Robert; Gerbaudo, Victor H; Castronovo, Frank P

    2004-03-01

    A mass casualty disaster drill involving the simulated explosion of a radiation dispersal device (dirty bomb) was performed with the participation of multiple hospitals, emergency responders, and governmental agencies. The exercise was designed to stress trauma service capacities, communications, safety, and logistic functions. We report our experience and critique of the planning, training, and execution of the exercise, with special attention to the integrated response of the Departments of Nuclear Medicine, Health Physics, and Emergency Medicine. The Health Physics Department presented multiple training sessions to the Emergency Medicine Department, Operating Room, and ancillary staff; reviewing basics of radiation biology and risk, protection standards, and detection of radiocontamination. Competency-based simulations using Geiger-Müller detectors and sealed sources were performed. Two nuclear medicine technologists played an important role in radiation discrimination-that is, assessment of radioactive contamination with survey meters and radionuclide identification based on gamma-spectroscopy of wipe smears from patients' clothing, skin, and orifices. Three Health Physics personnel and one senior Nuclear Medicine staff member were designated the radiation control officers for assigned teams triaging or treating patients. Patients were triaged and, when indicated, decontaminated. Within a 2-h period, 21 simulated victims arrived at our institution's Emergency Room. Of these, 11 were randomized as noncontaminated, with 10 as contaminated. Decontamination procedures were implemented in a hazardous materials (HAZMAT) decontamination trailer and, for the 5 patients with simulated serious injuries, in a designated trauma room. A full debriefing took place at the conclusion of the exercise. Staff largely complied with appropriate radiation protection protocols, although decontamination areas were not effectively controlled. The encountered limitations included

  12. Forty years experience in developing and using rainfall simulators under tropical and Mediterranean conditions

    Science.gov (United States)

    Pla-Sentís, Ildefonso; Nacci, Silvana

    2010-05-01

    Rainfall simulation has been used as a practical tool for evaluating the interaction of falling water drops on the soil surface, to measure both stability of soil aggregates to drop impact and water infiltration rates. In both cases it is tried to simulate the effects of natural rainfall, which usually occurs at very different, variable and erratic rates and intensities. One of the main arguments against the use of rainfall simulators is the difficulty to reproduce the size, final velocity and kinetic energy of the drops in natural rainfall. Since the early 70´s we have been developing and using different kinds of rainfall simulators, both at laboratory and field levels, and under tropical and Mediterranean soil and climate conditions, in flat and sloping lands. They have been mainly used to evaluate the relative effects of different land use and management, including different cropping systems, tillage practices, surface soil conditioning, surface covers, etc. on soil water infiltration, on runoff and on erosion. Our experience is that in any case it is impossible to reproduce the variable size distribution and terminal velocity of raindrops, and the variable changes in intensity of natural storms, under a particular climate condition. In spite of this, with the use of rainfall simulators it is possible to obtain very good information, which if it is properly interpreted in relation to each particular condition (land and crop management, rainfall characteristics, measurement conditions, etc.) may be used as one of the parameters for deducing and modelling soil water balance and soil moisture regime under different land use and management and variable climate conditions. Due to the possibility for a better control of the intensity of simulated rainfall and of the size of water drops, and the possibility to make more repeated measurements under very variable soil and land conditions, both in the laboratory and specially in the field, the better results have been

  13. The effect of an olfactory and visual cue on realism and engagement in a health care simulation experience.

    Science.gov (United States)

    Nanji, Karen C; Baca, Kirsten; Raemer, Daniel B

    2013-06-01

    Fidelity has been identified as an important element in a subject's perception of realism and engagement in learning during a simulation experience. The purpose of this study was to determine whether an isolated visual and olfactory sensory change to the simulation environment affects the subjects' perceptions of realism during simulation cases. Using an electrosurgical unit applied to bovine muscle tissue, we created a model to simulate the characteristic operating room smoke and burning odor that occur during many procedures. Anesthesiologist subjects were randomly assigned to an intervention group that participated in a simulation involving the characteristic smoke and odor or a control group whose simulation involved no smoke or odor. Subjects completed a 7-question survey on the fidelity of the simulation, their perception of realism, and their learning engagement. We enrolled 103 subjects over 22 simulation courses in our study (intervention, n = 52; control, n = 51). The subjects' reactions to the physical (P = 0.73), conceptual (P = 0.34), and emotional (P = 0.12) fidelity and their perception of realism (P = 0.71) did not differ between the intervention and control groups. In a high-fidelity simulation environment, a visual and olfactory increment to physical fidelity did not affect subjects' overall ratings of fidelity, perceptions of realism, and engagement in the learning experience.

  14. Simulation and design of feedback control on resistive wall modes in Keda Torus eXperiment

    International Nuclear Information System (INIS)

    Li, Chenguang; Liu, Wandong; Li, Hong

    2014-01-01

    The feedback control of resistive wall modes (RWMs) in Keda Torus eXperiment (KTX) (Liu et al., Plasma Phys. Controlled Fusion 56, 094009 (2014)) is investigated by simulation. A linear model is built to describe the growth of the unstable modes in the absence of feedback and the resulting mode suppression due to feedback, given the typical reversed field pinch plasma equilibrium. The layout of KTX with two shell structures (the vacuum vessel and the stabilizing shell) is taken into account. The feedback performance is explored both in the scheme of “clean mode control” (Zanca et al., Nucl. Fusion 47, 1425 (2007)) and “raw mode control.” The discrete time control model with specific characteristic times will mimic the real feedback control action and lead to the favored control cycle. Moreover, the conceptual design of feedback control system is also presented, targeting on both RWMs and tearing modes

  15. Simulation and Experiment Research on Fatigue Life of High Pressure Air Pipeline Joint

    Science.gov (United States)

    Shang, Jin; Xie, Jianghui; Yu, Jian; Zhang, Deman

    2017-12-01

    High pressure air pipeline joint is important part of high pressure air system, whose reliability is related to the safety and stability of the system. This thesis developed a new type-high pressure air pipeline joint, carried out dynamics research on CB316-1995 and new type-high pressure air pipeline joint with finite element method, deeply analysed the join forms of different design schemes and effect of materials on stress, tightening torque and fatigue life of joint. Research team set up vibration/pulse test bench, carried out joint fatigue life contrast test. The result shows: the maximum stress of the joint is inverted in the inner side of the outer sleeve nut, which is consistent with the failure mode of the crack on the outer sleeve nut in practice. Simulation and experiment of fatigue life and tightening torque of new type-high pressure air pipeline joint are better than CB316-1995 joint.

  16. Simulating and assessing boson sampling experiments with phase-space representations

    Science.gov (United States)

    Opanchuk, Bogdan; Rosales-Zárate, Laura; Reid, Margaret D.; Drummond, Peter D.

    2018-04-01

    The search for new, application-specific quantum computers designed to outperform any classical computer is driven by the ending of Moore's law and the quantum advantages potentially obtainable. Photonic networks are promising examples, with experimental demonstrations and potential for obtaining a quantum computer to solve problems believed classically impossible. This introduces a challenge: how does one design or understand such photonic networks? One must be able to calculate observables using general methods capable of treating arbitrary inputs, dissipation, and noise. We develop complex phase-space software for simulating these photonic networks, and apply this to boson sampling experiments. Our techniques give sampling errors orders of magnitude lower than experimental correlation measurements for the same number of samples. We show that these techniques remove systematic errors in previous algorithms for estimating correlations, with large improvements in errors in some cases. In addition, we obtain a scalable channel-combination strategy for assessment of boson sampling devices.

  17. Dust generation mechanisms under powerful plasma impacts to the tungsten surfaces in ITER ELM simulation experiments

    International Nuclear Information System (INIS)

    Makhlaj, V.A.; Garkusha, I.E.; Aksenov, N.N.; Chuvilo, A.A.; Chebotarev, V.V.; Landman, I.; Malykhin, S.V.; Pestchanyi, S.; Pugachov, A.T.

    2013-01-01

    In recent tokamak simulation experiments with the QSPA Kh-50 facility several mechanisms of dust generation from tungsten surfaces under ITER ELM-like energy loads have been identified. Here cracking and melting are reported. The brittle destruction dominates after a few transient impacts when a network of major cracks forms on the surface. Bifurcation of major cracks results in ejection of dust particles with sizes up to ∼30 μm. Dust generation occurs also after surface melting and following resolidification when fine crack networks along the grain boundaries develop. In this process the destruction is accompanied by bridge formation due to capillary tension across the fine cracks. Next impacts (even weak melt-free ones) can destroy those bridges, which produces considerable amounts of dust particles of nm-size dust. Surface modification after the repetitive plasma pulses also results in creation of nm-size dust

  18. Extraction of High Charge Electron Bunch from the ELSA RF Injector Comparison Between Simulation and Experiment

    CERN Document Server

    Lemaire, J; Binet, A; Lagniel, J M; Le Flanchec, V; Pichoff, N

    2004-01-01

    A new scheme based on a photoinjector and a RF linear accelerator operating at 352 MHz has been recently proposed as a versatile radiographic facility. Beam pulses of 60 ns duration contain 20 succesive electron bunches which will be extracted at 2.5 MeV from a photoinjector then accelerated through the next structure to the final energy of 51 MeV. Bunches carrying 100 nC are required for this purpose. As a first demonstrating step, 50 nC electron bunches have been produced and accelerated to 2.5 MeV with the 144 MHz ELSA photoinjector at Bruyères le Chatel. For this experiment, we compare the results and the numerical simulations made with PARMELA, MAGIC and MAFIA codes.

  19. Performance and Evaluation of the Global Modeling and Assimilation Office Observing System Simulation Experiment

    Science.gov (United States)

    Prive, Nikki; Errico, R. M.; Carvalho, D.

    2018-01-01

    The National Aeronautics and Space Administration Global Modeling and Assimilation Office (NASA/GMAO) has spent more than a decade developing and implementing a global Observing System Simulation Experiment framework for use in evaluting both new observation types as well as the behavior of data assimilation systems. The NASA/GMAO OSSE has constantly evolved to relect changes in the Gridpoint Statistical Interpolation data assimiation system, the Global Earth Observing System model, version 5 (GEOS-5), and the real world observational network. Software and observational datasets for the GMAO OSSE are publicly available, along with a technical report. Substantial modifications have recently been made to the NASA/GMAO OSSE framework, including the character of synthetic observation errors, new instrument types, and more sophisticated atmospheric wind vectors. These improvements will be described, along with the overall performance of the current OSSE. Lessons learned from investigations into correlated errors and model error will be discussed.

  20. Burnout experiments in freon 12 using different types of orifices to simulate the core grids

    International Nuclear Information System (INIS)

    Ladeira, L.; Katsaounis, A.; Orlowski, R.; Fulfs, H.; Hofmann, K.

    1978-01-01

    This paper will report on burnout experiments carried out in freon 12 mainly at steady state and further at mass flow or power transient conditions with annular test sections axially uniformly heating either the inside or both the inside and outside rod. The runs are performed without orifice and using three different types of orifices simulating the reactor spacer grid. An important influence of the flow restriction on burnout position and value is measured. Furthermore, the comparison between the burnout correlations W2, W3, B and W2 and GE and experimental results from the literature using simple test section geometries in water and freon 12 demonstrate, that the accuracy is more or less comparable for both fluids. (orig.) [de

  1. Determination of material parameters by comparison of 3D simulations and 3D experiments

    DEFF Research Database (Denmark)

    Zhang, Jin

    microstructure and the measured microstructure in a global manner. The proposed method is demonstrated on a simple case to fit two material parameters: the liquid diffusion coefficient and the capillary length of a hypoeutectic Al-Cu alloy, and a complicated case to fit hundreds of material parameters......Computer-based materials design plays an essential role in the development of new materials. Accurate prediction of the materials behavior during manufacturing and applications relies on accurate and complete materials databases. Traditional ways of material parameters measurements typically use...... methodology is proposed to determine material parameters by comparison between 4D x-ray experiments and phase-field simulations. The evolution of material microstructures is measured at a condition that mimics realistic engineering manufacturing and applications with 3D non-destructive in situ x...

  2. Simulation and measurement of the suppression of radon induced background in the KATRIN experiment

    Science.gov (United States)

    Wolf, J.; Harms, F.

    2018-01-01

    Short-lived radon isotopes, such as 219Rn or 220Rn, are a serious source of background for the measurement of the neu-trino mass with the KATRIN experiment. Most of the radon emanates from the main vacuum pumps of the KATRIN Main Spec-trometer, which consist of 2000 m of Non-Evaporable Getter (NEG) strips. This paper describes a method to suppress the radon rate with liquid-nitrogen-cooled baffles in front of the NEG-pumps in the ultra-high vacuum chamber and compares simulations with measured data. The effectiveness of the method depends both on the half-life of the radon isotopes, and on the temperature of the cryogenic baffles, which affects their sojourn time on the cold surface. The measurements with the Main Spectrometer showed that the radon suppression with cold baffles works sufficiently well, so that the remaining background is no longer dominated by radon decays.

  3. New tools and technology for the study of human performance in simulator experiments

    International Nuclear Information System (INIS)

    Droeivoldsmo, Asgeir

    2004-04-01

    The Halden Virtual Reality Centre has for the last four years reported a number of experiments in the area of real world application of virtual and augmented reality technology. The insights from these studies have been reviewed and reported as part of a PhD-thesis submitted at the Norwegian University of Science and Technology. This report is based on the thesis and contains a theoretical discussion of how the virtual and augmented reality technology could be used to extend human operator performance in control rooms to include co-operation with plant floor personnel and interaction with not already built equipment. This thesis suggests that new tools and technology can be used for production of relevant data and insights from the study of human performance in simulator and field experiments. It examines some of the theoretical perspectives behind data collection and human performance assessment, and argues for a high resemblance of the real world and use of subject matter expertise in simulator studies. A model is proposed, suggesting that human performance measurement should be tightly coupled to the topic of study and have a close connection to the time line. This coupling requires new techniques for continuous data collection, and eye movement tracking has been identified as a promising basis for this type of measures. One way of improving realism is to create virtual environments allowing for controlling more of the environment surrounding the test subjects. New application areas for virtual environments are discussed for use in control room and field studies. The combination of wearable computing, virtual and augmented (the use of computers to overlay virtual information onto the real world) reality provides many new possibilities to present information to operators. In two experiments, virtual and augmented reality techniques were used to visualise radiation fields for operators in a contaminated nuclear environment. This way the operators could train for

  4. Time-course human urine proteomics in space-flight simulation experiments.

    Science.gov (United States)

    Binder, Hans; Wirth, Henry; Arakelyan, Arsen; Lembcke, Kathrin; Tiys, Evgeny S; Ivanisenko, Vladimir A; Kolchanov, Nikolay A; Kononikhin, Alexey; Popov, Igor; Nikolaev, Evgeny N; Pastushkova, Lyudmila; Larina, Irina M

    2014-01-01

    Long-term space travel simulation experiments enabled to discover different aspects of human metabolism such as the complexity of NaCl salt balance. Detailed proteomics data were collected during the Mars105 isolation experiment enabling a deeper insight into the molecular processes involved. We studied the abundance of about two thousand proteins extracted from urine samples of six volunteers collected weekly during a 105-day isolation experiment under controlled dietary conditions including progressive reduction of salt consumption. Machine learning using Self Organizing maps (SOM) in combination with different analysis tools was applied to describe the time trajectories of protein abundance in urine. The method enables a personalized and intuitive view on the physiological state of the volunteers. The abundance of more than one half of the proteins measured clearly changes in the course of the experiment. The trajectory splits roughly into three time ranges, an early (week 1-6), an intermediate (week 7-11) and a late one (week 12-15). Regulatory modes associated with distinct biological processes were identified using previous knowledge by applying enrichment and pathway flow analysis. Early protein activation modes can be related to immune response and inflammatory processes, activation at intermediate times to developmental and proliferative processes and late activations to stress and responses to chemicals. The protein abundance profiles support previous results about alternative mechanisms of salt storage in an osmotically inactive form. We hypothesize that reduced NaCl consumption of about 6 g/day presumably will reduce or even prevent the activation of inflammatory processes observed in the early time range of isolation. SOM machine learning in combination with analysis methods of class discovery and functional annotation enable the straightforward analysis of complex proteomics data sets generated by means of mass spectrometry.

  5. Comparative evaluation of two sediment tracers in a rainfall simulation experiment

    Science.gov (United States)

    Strauss, Peter; Guzman, Gema; Mentler, Axel

    2015-04-01

    The use of sediment tracers tries to contribute to solving problems of traditional soil erosion measurements such as allocation of erosional and depositional areas. A number of different tracing approaches have already been established however, as none of available techniques are able to fully satisfy all the requirements for being an ideal tracer the search for alternative methods continues. Clays tagged with quaternary ammonium compounds are widely used in industry and are easy to incorporate into soils for sediment tracing experiments. To explore the potential of these clays a laboratory experiment was carried out in order to characterize their behaviour as compared to the well-established sediment tracer magnetic iron oxide. The experiment consisted of a simulated rainfall event of 60 mm/h in a box laboratory flume divided in two ridge-furrow subplots (200 x 57 cm). In order to evaluate transport and redistribution of soil from the ridges to the furrow and to measure the dynamic behaviour of the tracers during the rainfall a dense grid of soil samples was taken before and after the experiment (140 samples in total). Runoff and sediment were collected and all samples were analysed for both tracers. Results indicate the general suitability of organophilic clays to monitor soil redistribution by water erosion. The average relative contributions from shoulders and furrow to total sediment export determined by both tracers were similar and indicated a higher contribution from ridges. A key advantage of using organophilic clays is that the detection limit of organophilic clays is extremely low and the background concentration is zero. Despite the inherent differences between both tracers such as way of bounding, sediment enrichment or analytical technique, this experimental comparison of an established and more novel tracer method underscores the potential suitability of the latter for soil erosion studies.

  6. Cyclic Bending and Stationary Drawing Deformation of Metal Sheets : Experiments and Associated Numerical Simulations

    Science.gov (United States)

    Moreira, L. P.; Romão, E. C.; Ferron, G.; Vieira, L. C. A.; Sampaio, A. P.

    2005-08-01

    A simple bend-draw experimental device is employed to analyze the behavior of narrow strips submitted to a nearly cyclic bending deformation mode followed by a steady state drawing. In this bending-drawing experiment, the strip is firstly bent over a central bead and two lateral beads by applying a controlled holding load and then is pulled out of device throughout the bead radii by a drawing load. The apparatus is mounted in a standard tensile test machine where the holding and drawing loads are recorded with an acquisition data system. The specimen is a rectangular strip cut with 320 mm long and 7 mm wide. The longitudinal (1) and width (w) strip plastic strains are determined from two hardness marks 120 mm spaced whereas the corresponding thickness (t) strain is obtained by volume conservation. Previous experiments showed a correlation between the plastic strain (ɛw/ɛt)BD resulting from the bending-drawing and the Lankford R-values obtained from the uniaxial tensile test. However, previous 3D numerical simulations based upon Hill's quadratic and Ferron's yield criteria revealed a better correlation between the (ɛw/ɛt)BD and the stress ratio σPS/σ(α), where σPS stands for the plane-strain tension yield stress and σ(α) for the uniaxial yield stress in uniaxial tension along the drawing direction making an angle α with the rolling direction. In the present work, the behavior of an IF steel sheet is firstly evaluated by means of uniaxial tensile and drawing-bending experiments conducted at every 15 degrees with respect to the rolling direction. Afterwards, the bending-drawing experiment is investigated with the commercial finite element (FE) code ABAQUS/Standard in an attempt to assess the influence of cyclic loadings upon the bending-drawing strain-ratios.

  7. Simulations of radiation pressure experiments narrow down the energy and momentum of light in matter

    International Nuclear Information System (INIS)

    Bethune-Waddell, Max; Chau, Kenneth J

    2015-01-01

    Consensus on a single electrodynamic theory has yet to be reached. Discord was seeded over a century ago when Abraham and Minkowski proposed different forms of electromagnetic momentum density and has since expanded in scope with the gradual introduction of other forms of momentum and force densities. Although degenerate sets of electrodynamic postulates can be fashioned to comply with global energy and momentum conservation, hope remains to isolate a single theory based on detailed comparison between force density predictions and radiation pressure experiments. This comparison is two-fold challenging because there are just a handful of quantitative radiation pressure measurements over the past century and the solutions developed from different postulates, which consist of approximate expressions and inferential deductions, are scattered throughout the literature. For these reasons, it is appropriate to conduct a consolidated and comprehensive re-analysis of past experiments under the assumption that the momentum and energy of light in matter are degenerate. We create a combined electrodynamic/fluid dynamic simulation testbed that uses five historically significant sets of electrodynamic postulates, including those by Abraham and Minkowski, to model radiation pressure under diverse configurations with minimal assumptions. This leads to new interpretations of landmark investigations of light momentum, including the Balazs thought experiment, the Jones–Richards and Jones–Leslie measurements of radiation pressure on submerged mirrors, observations of laser-deformed fluid surfaces, and experiments on optical trapping and tractor beaming of dielectric particles. We discuss the merits and demerits of each set of postulates when compared to available experimental evidence and fundamental conservation laws. Of the five sets of postulates, the Abraham and Einstein–Laub postulates provide the greatest consistency with observations and the most physically plausible

  8. Experiments and simulation of a net closing mechanism for tether-net capture of space debris

    Science.gov (United States)

    Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

    2017-10-01

    This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

  9. Identifying and tracking simulated synaptic inputs from neuronal firing: insights from in vitro experiments.

    Directory of Open Access Journals (Sweden)

    Maxim Volgushev

    2015-03-01

    Full Text Available Accurately describing synaptic interactions between neurons and how interactions change over time are key challenges for systems neuroscience. Although intracellular electrophysiology is a powerful tool for studying synaptic integration and plasticity, it is limited by the small number of neurons that can be recorded simultaneously in vitro and by the technical difficulty of intracellular recording in vivo. One way around these difficulties may be to use large-scale extracellular recording of spike trains and apply statistical methods to model and infer functional connections between neurons. These techniques have the potential to reveal large-scale connectivity structure based on the spike timing alone. However, the interpretation of functional connectivity is often approximate, since only a small fraction of presynaptic inputs are typically observed. Here we use in vitro current injection in layer 2/3 pyramidal neurons to validate methods for inferring functional connectivity in a setting where input to the neuron is controlled. In experiments with partially-defined input, we inject a single simulated input with known amplitude on a background of fluctuating noise. In a fully-defined input paradigm, we then control the synaptic weights and timing of many simulated presynaptic neurons. By analyzing the firing of neurons in response to these artificial inputs, we ask 1 How does functional connectivity inferred from spikes relate to simulated synaptic input? and 2 What are the limitations of connectivity inference? We find that individual current-based synaptic inputs are detectable over a broad range of amplitudes and conditions. Detectability depends on input amplitude and output firing rate, and excitatory inputs are detected more readily than inhibitory. Moreover, as we model increasing numbers of presynaptic inputs, we are able to estimate connection strengths more accurately and detect the presence of connections more quickly. These results

  10. Vacuum UV spectroscopy of armor erosion from plasma gun disruption simulation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rockett, P.D. [Sandia Nat. Labs., Albuquerque, NM (United States). Fusion Tech. Dept.; Hunter, J.A. [Sandia Nat. Labs., Albuquerque, NM (United States). Fusion Tech. Dept.; Bradley, J.T. III [Electrical Engineering and Computer Engineering Department, University of New Mexico, Albuquerque, NM 87131 (United States); Gahl, J.M. [Electrical Engineering and Computer Engineering Department, University of New Mexico, Albuquerque, NM 87131 (United States); Zhitlukhin, A. [Troitsk Institute for Innovation and Technology (TRINITI), Troitsk, Moscow Region (Russian Federation); Arkhipov, K. [Troitsk Institute for Innovation and Technology (TRINITI), Troitsk, Moscow Region (Russian Federation); Bakhtin, V. [Troitsk Institute for Innovation and Technology (TRINITI), Troitsk, Moscow Region (Russian Federation); Toporkov, D. [Troitsk Institute for Innovation and Technology (TRINITI), Troitsk, Moscow Region (Russian Federation); Ovchinnokov, I. [Research Inst. of Electrophysical Apparatus, St. Petersburg (Russian Federation); Kuznetsov, V.E. [Research Inst. of Electrophysical Apparatus, St. Petersburg (Russian Federation); Titov, V.A. [Research Inst. of Electrophysical Apparatus, St. Petersburg (Russian Federation)

    1995-03-01

    Extensive simulations of tokamak disruptions have provided a picture of material erosion that is limited by the transfer of energy from the incident plasma to the armor solid surface through a dense vapor shield. Two transmission grating vacuum ultraviolet (VUV) spectrographs were designed and utilized to study the plasma-material interface in plasma gun simulation experiments. Target materials included POCO graphite, ATJ graphite, boron nitride and plasma-sprayed tungsten. Detailed spectra were recorded with a spatial resolution of ca. 0.7mm resolution on VIKA at Efremov and on 2MK-200 at Troitsk. Time-resolved data with 40-200ns resolution were then recorded along with the same spatial resolution on 2MK-200. The VIKA plasma gun directly illuminated a target with a high-intensity plasma pulse of 2-100MJm{sup -2} with low-energy ions of ca. 100eV. The 2MK-200 plasma gun illuminated the target via a magnetic cusp that permitted only deuterium to pass with energies of ca. 1keV, but which produced a fairly low intensity of 2MJm{sup -2}. Power densities on target ranged from 10{sup 7} to 10{sup 8}Wcm{sup -2}. Emitted spectra were recorded from 15 to 450A over a distance from 0 to 7cm above the armor target surface. The data from both plasma gun facilities demonstrated that the hottest plasma region was sitting several millimeters above the armor tile surface. This apparently constituted the absorption region, which confirmed past computer simulations. Spectra indicated both the species and ionization level that were being ablated from the target, demonstrating impurity content, and showing plasma ablation velocity. Graphite samples clearly showed CV lines as well as impurity lines from O V and O VI. The BN tiles produced textbook examples of BIV and BV, and extensive NIV, V and VI lines. These are being compared with radiation-hydrodynamic calculations. (orig.).

  11. DEM Simulation of Biaxial Compression Experiments of Inherently Anisotropic Granular Materials and the Boundary Effects

    Directory of Open Access Journals (Sweden)

    Zhao-Xia Tong

    2013-01-01

    Full Text Available The reliability of discrete element method (DEM numerical simulations is significantly dependent on the particle-scale parameters and boundary conditions. To verify the DEM models, two series of biaxial compression tests on ellipse-shaped steel rods are used. The comparisons on the stress-strain relationship, strength, and deformation pattern of experiments and simulations indicate that the DEM models are able to capture the key macro- and micromechanical behavior of inherently anisotropic granular materials with high fidelity. By using the validated DEM models, the boundary effects on the macrodeformation, strain localization, and nonuniformity of stress distribution inside the specimens are investigated using two rigid boundaries and one flexible boundary. The results demonstrate that the boundary condition plays a significant role on the stress-strain relationship and strength of granular materials with inherent fabric anisotropy if the stresses are calculated by the force applied on the wall. However, the responses of the particle assembly measured inside the specimens are almost the same with little influence from the boundary conditions. The peak friction angle obtained from the compression tests with flexible boundary represents the real friction angle of particle assembly. Due to the weak lateral constraints, the degree of stress nonuniformity under flexible boundary is higher than that under rigid boundary.

  12. Gas solubility of carbon dioxide and of oxygen in cyclohexanol by experiment and molecular simulation

    International Nuclear Information System (INIS)

    Merker, T.; Vrabec, J.; Hasse, H.

    2012-01-01

    Highlights: ► Gas solubility measurements of carbon dioxide in liquid cyclohexanol are reported. ► Gas solubility measurements of oxygen in liquid cyclohexanol are reported. ► Henry’s law constant data is determined from the present experimental results. ► Very good agreement between experiment and molecular simulation is achieved. ► Ambiguity for the Henry’s law constant of oxygen in cyclohexanol is resolved. - Abstract: Henry’s law constant data of carbon dioxide and of oxygen in liquid cyclohexanol are determined at temperatures between (303 and 392) K by means of a precise experimental high-pressure view-cell technique with a synthetic method. Furthermore, molecular simulations are carried out with a molecular mixture model, based on the modified Lorentz–Berthelot combination rule that contains one binary interaction parameter which is adjusted to one experimental Henry’s law constant for each binary mixture. The molecular model yields good results for the Henry’s law constant over the entire temperature range.

  13. Measurement and simulation of unmyelinated nerve electrostimulation: Lumbricus terrestris experiment and numerical model.

    Science.gov (United States)

    Šarolić, A; Živković, Z; Reilly, J P

    2016-06-21

    The electrostimulation excitation threshold of a nerve depends on temporal and frequency parameters of the stimulus. These dependences were investigated in terms of: (1) strength-duration (SD) curve for a single monophasic rectangular pulse, and (2) frequency dependence of the excitation threshold for a continuous sinusoidal current. Experiments were performed on the single-axon measurement setup based on Lumbricus terrestris having unmyelinated nerve fibers. The simulations were performed using the well-established SENN model for a myelinated nerve. Although the unmyelinated experimental model differs from the myelinated simulation model, both refer to a single axon. Thus we hypothesized that the dependence on temporal and frequency parameters should be very similar. The comparison was made possible by normalizing each set of results to the SD time constant and the rheobase current of each model, yielding the curves that show the temporal and frequency dependencies regardless of the model differences. The results reasonably agree, suggesting that this experimental setup and method of comparison with SENN model can be used for further studies of waveform effect on nerve excitability, including unmyelinated neurons.

  14. Numerical simulation and experiment of high-intensity current pulsed impact on the structure body

    International Nuclear Information System (INIS)

    Li Mintang; Yan Ping; Yuan Weiqun; Sun Yaohong; Sun Lianhua; Zhou Yuan; Liu Chuanpu

    2010-01-01

    To better understand the characteristics of the impulse force formed by pulse current of electromagnetic rail propulsion system, and to explore effective ways to improve the support structure of rails, a set of impulse force test system was designed, and the work-related test situation was numerically simulated. Several impulse force waveforms formed by different pulse current waveforms were achieved by using an armature as a source of impulse force in this test system, and two curves of waveform were comparatively analyzed. The armature existing in the environment of coupling fields including electric field and magnetic field and force field was carried out numerical calculation by using the software of ANSYS, and the coupling force field was emphatically analyzed to calculate the electromagnetic driving force and the electromagnetic clamping force acting on the armature, and the structure stress and deformation was also analyzed. The results showed that the curves of electromagnetic driving force computed by numerical simulation and the curves of impulse force obtained by experiment were basically the same, and the value of peak points' error was increasing along with the increase of pulse current, but the curves still showed some common characteristics. This verified that the test method we used in this paper was proper to capture the impulse force, and the method of calculation was also feasible and effective. (authors)

  15. Fire simulation in nuclear facilities--the FIRAC code and supporting experiments

    International Nuclear Information System (INIS)

    Burkett, M.W.; Martin, R.A.; Fenton, D.L.; Gunaji, M.V.

    1985-01-01

    The fire accident analysis computer code FIRAC was designed to estimate radioactive and nonradioactive source terms and predict fire-induced flows and thermal and material transport within the ventilation systems of nuclear fuel cycle facilities. FIRAC maintains its basic structure and features and has been expanded and modified to include the capabilities of the zone-type compartment fire model computer code FIRIN developed by Battelle Pacific Northwest Laboratory. The two codes have been coupled to provide an improved simulation of a fire-induced transient within a facility. The basic material transport capability of FIRAC has been retained and includes estimates of entrainment, convection, deposition, and filtration of material. The interrelated effects of filter plugging, heat transfer, gas dynamics, material transport, and fire and radioactive source terms also can be simulated. Also, a sample calculation has been performed to illustrate some of the capabilities of the code and how a typical facility is modeled with FIRAC. In addition to the analytical work being performed at Los Alamos, experiments are being conducted at the New Mexico State University to support the FIRAC computer code development and verification. This paper summarizes two areas of the experimental work that support the material transport capabilities of the code: the plugging of high-efficiency particulate air (HEPA) filters by combustion aerosols and the transport and deposition of smoke in ventilation system ductwork

  16. TOUGH-RBSN simulator for hydraulic fracture propagation within fractured media: Model validations against laboratory experiments

    Science.gov (United States)

    Kim, Kunhwi; Rutqvist, Jonny; Nakagawa, Seiji; Birkholzer, Jens

    2017-11-01

    This paper presents coupled hydro-mechanical modeling of hydraulic fracturing processes in complex fractured media using a discrete fracture network (DFN) approach. The individual physical processes in the fracture propagation are represented by separate program modules: the TOUGH2 code for multiphase flow and mass transport based on the finite volume approach; and the rigid-body-spring network (RBSN) model for mechanical and fracture-damage behavior, which are coupled with each other. Fractures are modeled as discrete features, of which the hydrological properties are evaluated from the fracture deformation and aperture change. The verification of the TOUGH-RBSN code is performed against a 2D analytical model for single hydraulic fracture propagation. Subsequently, modeling capabilities for hydraulic fracturing are demonstrated through simulations of laboratory experiments conducted on rock-analogue (soda-lime glass) samples containing a designed network of pre-existing fractures. Sensitivity analyses are also conducted by changing the modeling parameters, such as viscosity of injected fluid, strength of pre-existing fractures, and confining stress conditions. The hydraulic fracturing characteristics attributed to the modeling parameters are investigated through comparisons of the simulation results.

  17. Simulation and experiment of the static FTIR based on micro multi-step mirrors

    Science.gov (United States)

    Liang, Jingqiu; Liang, Zhong-zhu; Lv, Jin-guang; Fu, Jian-guo; Zheng, Ying; Feng, Cong; Wang, Wei-biao; Zhu, Wan-bin; Yao, Jin-song; Zhang, Jun

    2011-08-01

    In recent years, Fourier transform spectrometer (FTS) with small size and low mass is required in many applications with growing need for real-time and small platform spectral detection. In this paper, a micro Fourier transform infrared spectrometer (μFTIR) based on spatial modulation mode was designed. This spectrometer has the advantages of high stability and simplified configuration. It also promises optical path differences (OPD) with high precision, as MOEMS technology is used in manufacturing the key components. The simulation and the experiments with regard to this FTIR configuration have been done. Firstly, the diffraction effect of the micro multi-step mirrors (MMSMs) is studied. We discuss the influence to the reversed spectrum by different mirror widths and different diffraction distances. Secondly, we simulate and analyze the influence of the source solid angle to the spectral resolution. Thirdly, we set up the theoretical model of the collimation error which is mainly from the defocus of the optical system and analyze the result caused by the collimation error. Fourthly, a new discrete Fourier transform arithmetic using least-squares cosines progression (LSCP) is proposed which can reconstruct the spectrum with nonuniform sampled signals. Finally, the MMSMs are fabricated used the MOEMS technology and the structural parameters are tested.

  18. Early MIMD experience with a plasma physics simulation program on the CRAY X-MP

    International Nuclear Information System (INIS)

    Rhoades, C.E. Jr.

    1986-02-01

    This paper describes some early experience with converting a plasma physics simulation program to the CRAY X-MP, a current multiple instruction, multiple data (MIMD) computer consisting of two processors with architecture similar to that of the CRAY-1. The computer program used in this study is an all Fortran version of SELF, a two species, one space, two velocity, electromagnetic, Newtonian, particle in cell, plasma simulation code. The approach to converting SELF to use both processors of the CRAY X-MP is described in some detail. The resulting multiprocessor version of SELF is nearly a factor of two faster in real time than the single processor version. The multiprocessor version obtains 58.2+-.1 seconds of central processor time in 30+-.5 seconds of real time. For comparison, the CRAY-1 execution time if 74.5 seconds. For SELF, which is mostly scalar coding, the CRAY X-MP is about 2.5 times faster overall than the CRAY-1

  19. Building the equation of state of TATB from ab initio simulations and DAC experiments

    Science.gov (United States)

    Pineau, Nicolas; Plisson, Thomas; Sollier, Arnaud

    2017-06-01

    Modelling equations of state for energetic molecular crystals in the full thermodynamic range of inert compression, prior to detonation, is a challenging issue. Indeed the unreacted regime under high pressure is difficult to explore experimentally, and although first principle calculations allow filling that gap, the need for experimental support is crucial in order to validate the chosen methodological approach, and in fine the simulation results. In this study we present our methodology for building ab initio based EOSs for molecular crystals, using van der Waals corrected DFT and Path Integral Molecular Dynamics (PIMD). Then we present recent experimental results on the isotropic compression of TATB using diamond anvil cells (DAC) and synchrotron radiation to reach pressures up to 65 GPa, beyond the current estimations for the von Neumann spike. The close agreement between the experimental and simulation data validates the methodology employed to obtain the cold curve of the explosive. The shock properties of inert TATB obtained with this EOS compare well to recent laser-driven shock compression experiments.

  20. Epitaxy of oligothiophenes on alkali metal hydrogen phthalates: Simulations and experiments.

    Science.gov (United States)

    Trabattoni, S; Raimondo, L; Sassella, A; Moret, M

    2017-03-28

    Three alkali metal hydrogen phthalate salts (denoted as XAP, X = K + , Rb + , and Cs + ) are chosen as substrates for the growth of quaterthiophene (4T) and hexathiophene (6T) thin films by organic molecular beam epitaxy to study the influence of gradual changes of surface unit cell parameters on the epitaxialgrowth. The increment of substrate lattice parameters increases the distance between the planes that define the furrows where oligothiophene molecules lie, while keeping unmodified the interactions between the overlayer and the substrate. Atom-atom potential simulations predict the preferential azimuthal orientations of the overlayer, which are compared with those experimentally observed. The agreement between simulations and experiments about contact planes and orientation of the crystalline domains in the films is satisfactory for both 4T/XAP and 6T/XAP. The increasing width of the surface furrows existing on moving from KAP to RbAP and CsAP does not cause any significant variation of the orientation and density of the overlayer domains, demonstrating that the interaction between overlayer and substrate is the key factor guiding organic epitaxialgrowth.