WorldWideScience

Sample records for shock compaction experiments

  1. Shock compaction of molybdenum powder

    Science.gov (United States)

    Ahrens, T. J.; Kostka, D.; Vreeland, T., Jr.; Schwarz, R. B.; Kasiraj, P.

    1983-01-01

    Shock recovery experiments which were carried out in the 9 to 12 GPa range on 1.4 distension Mo and appear adequate to compact to full density ( 45 (SIGMA)m) powders were examined. The stress levels, however, are below those calculated to be from 100 to approx. 22 GPa which a frictional heating model predicts are required to consolidate approx. 10 to 50 (SIGMA)m particles. The model predicts that powders that have a distension of m=1.6 shock pressures of 14 to 72 GPa are required to consolidate Mo powders in the 50 to 10 (SIGMA)m range.

  2. Optimal Bayesian experimental design for priors of compact support with application to shock-tube experiments for combustion kinetics

    KAUST Repository

    Bisetti, Fabrizio

    2016-01-12

    The analysis of reactive systems in combustion science and technology relies on detailed models comprising many chemical reactions that describe the conversion of fuel and oxidizer into products and the formation of pollutants. Shock-tube experiments are a convenient setting for measuring the rate parameters of individual reactions. The temperature, pressure, and concentration of reactants are chosen to maximize the sensitivity of the measured quantities to the rate parameter of the target reaction. In this study, we optimize the experimental setup computationally by optimal experimental design (OED) in a Bayesian framework. We approximate the posterior probability density functions (pdf) using truncated Gaussian distributions in order to account for the bounded domain of the uniform prior pdf of the parameters. The underlying Gaussian distribution is obtained in the spirit of the Laplace method, more precisely, the mode is chosen as the maximum a posteriori (MAP) estimate, and the covariance is chosen as the negative inverse of the Hessian of the misfit function at the MAP estimate. The model related entities are obtained from a polynomial surrogate. The optimality, quantified by the information gain measures, can be estimated efficiently by a rejection sampling algorithm against the underlying Gaussian probability distribution, rather than against the true posterior. This approach offers a significant error reduction when the magnitude of the invariants of the posterior covariance are comparable to the size of the bounded domain of the prior. We demonstrate the accuracy and superior computational efficiency of our method for shock-tube experiments aiming to measure the model parameters of a key reaction which is part of the complex kinetic network describing the hydrocarbon oxidation. In the experiments, the initial temperature and fuel concentration are optimized with respect to the expected information gain in the estimation of the parameters of the target

  3. Compact ignition experiments

    International Nuclear Information System (INIS)

    Angelini, A.; Coppi, B.; Nassi, M.

    1992-01-01

    This paper reports on high magnetic field experiments which can be designed to investigate D-T ignition conditions based on present-day experimental results and theoretical understanding of plasma phenomena. The key machine elements are: large plasma currents, compact dimensions, tight aspect ratios, moderate elongations and significant triangularities of the plasma column. High plasma densities, strong ohmic heating, the needed degree of energy confinement, good plasma purity and robust stability against ideal and resistive instabilities can be achieved simultaneously. The Ignitor design incorporates all these characteristics and involves magnet technology developments, started with the Alcator experiment, that use cryogenically cooled normal conductors

  4. Effect of target-fixture geometry on shock-wave compacted copper powders

    Science.gov (United States)

    Kim, Wooyeol; Ahn, Dong-Hyun; Yoon, Jae Ik; Park, Lee Ju; Kim, Hyoung Seop

    2018-01-01

    In shock compaction with a single gas gun system, a target fixture is used to safely recover a powder compact processed by shock-wave dynamic impact. However, no standard fixture geometry exists, and its effect on the processed compact is not well studied. In this study, two types of fixture are used for the dynamic compaction of hydrogen-reduced copper powders, and the mechanical properties and microstructures are investigated using the Vickers microhardness test and electron backscatter diffraction, respectively. With the assistance of finite element method simulations, we analyze several shock parameters that are experimentally hard to control. The results of the simulations indicate that the target geometry clearly affects the characteristics of incident and reflected shock waves. The hardness distribution and the microstructure of the compacts also show their dependence on the geometry. With the results of the simulations and the experiment, it is concluded that the target geometry affects the shock wave propagation and wave interaction in the specimen.

  5. Shock tube Multiphase Experiments

    Science.gov (United States)

    Middlebrooks, John; Allen, Roy; Paudel, Manoj; Young, Calvin; Musick, Ben; McFarland, Jacob

    2017-11-01

    Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. It is similar in development to the Richtmyer-Meshkov (RM) instability however, particle-to-gas coupling is the driving mechanism of the SDMI. As particle effects such as lag and phase change become more prominent, the SDMI's development begins to significantly deviate from the RM instability. We have developed an experiment for studying the SDMI in our shock tube facility. In our experiments, a multiphase interface is created using a laminar jet and flowed into the shock tube where it is accelerated by the passage of a planar shockwave. The interface development is captured using CCD cameras synchronized with planar laser illumination. This talk will give an overview of new experiments conducted to examine the development of a shocked cylindrical multiphase interface. The effects of Atwood number, particle size, and a second acceleration (reshock) of the interface will be discussed.

  6. Compaction shock dissipation in low density granular explosive

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Pratap T.; Gonthier, Keith A., E-mail: gonthier@me.lsu.edu; Chakravarthy, Sunada [Mechanical and Industrial Engineering Department, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

    2016-06-14

    The microstructure of granular explosives can affect dissipative heating within compaction shocks that can trigger combustion and initiate detonation. Because initiation occurs over distances that are much larger than the mean particle size, homogenized (macroscale) theories are often used to describe local thermodynamic states within and behind shocks that are regarded as the average manifestation of thermodynamic fields at the particle scale. In this paper, mesoscale modeling and simulation are used to examine how the initial packing density of granular HMX (C{sub 4}H{sub 8}N{sub 8}O{sub 8}) C{sub 4}H{sub 8}N{sub 8}O{sub 8} having a narrow particle size distribution influences dissipation within resolved, planar compaction shocks. The model tracks the evolution of thermomechanical fields within large ensembles of particles due to pore collapse. Effective shock profiles, obtained by averaging mesoscale fields over space and time, are compared with those given by an independent macroscale compaction theory that predicts the variation in effective thermomechanical fields within shocks due to an imbalance between the solid pressure and a configurational stress. Reducing packing density is shown to reduce the dissipation rate within shocks but increase the integrated dissipated work over shock rise times, which is indicative of enhanced sensitivity. In all cases, dissipated work is related to shock pressure by a density-dependent power law, and shock rise time is related to pressure by a power law having an exponent of negative one.

  7. Analysis of compaction shock interactions during DDT of low density HMX

    Science.gov (United States)

    Rao, Pratap T.; Gonthier, Keith A.

    2017-01-01

    Deflagration-to-Detonation Transition (DDT) in confined, low density granular HMX occurs by a complex mechanism that involves compaction shock interactions within the material. Piston driven DDT experiments indicate that detonation is abruptly triggered by the interaction of a strong combustion-supported secondary shock and a piston-supported primary (input) shock, where the nature of the interaction depends on initial packing density and primary shock strength. These interactions influence transition by affecting dissipative heating within the microstructure during pore collapse. Inert meso-scale simulations of successive shock loading of low density HMX are performed to examine how dissipation and hot-spot formation are affected by the initial density, and the primary and secondary shock strengths. This information is used to formulate an ignition and burn model for low density HMX that accounts for the effect of shock densensitization on burn. Preliminary DDT predictions are presented that illustrate how primary shock strength affects the transition mechanism.

  8. Compact all-fiber interferometer system for shock acceleration measurement

    Science.gov (United States)

    Zhao, Jiang; Pi, Shaohua; Hong, Guangwei; Zhao, Dong; Jia, Bo

    2013-08-01

    Acceleration measurement plays an important role in a variety of fields in science and engineering. In particular, the accurate, continuous and non-contact recording of the shock acceleration profiles of the free target surfaces is considered as a critical technique in shock physics. Various kinds of optical interferometers have been developed to monitor the motion of the surfaces of shocked targets since the 1960s, for instance, the velocity interferometer system for any reflector, the fiber optic accelerometer, the photonic Doppler velocimetry system and the displacement interferometer. However, most of such systems rely on the coherent quasi-monochromatic illumination and discrete optic elements, which are costly in setting-up and maintenance. In 1996, L. Levin et al reported an interferometric fiber-optic Doppler velocimeter with high-dynamic range, in which fiber-coupled components were used to replace the discrete optic elements. However, the fringe visibility of the Levin's system is low because of the coupled components, which greatly limits the reliability and accuracy in the shock measurement. In this paper, a compact all-fiber interferometer system for measuring the shock acceleration is developed and tested. The advantage of the system is that not only removes the non-interfering light and enhances the fringe visibility, but also reduces polarization induced signal fading and the polarization induced phase shift. Moreover, it also does not require a source of long coherence length. The system bases entirely on single-mode fiber optics and mainly consists of a polarization beam splitter, a faraday rotator, a depolarizer and a 3×3 single-mode fiber coupler which work at 1310 nm wavelength. The optical systems of the interferometer are described and the experimental results compared with a shock acceleration calibration system with a pneumatic exciter (PneuShockTM Model 9525C by The Modal Shop) are reported. In the shock acceleration test, the

  9. Mesoscale simulations of shock compaction of a granular ceramic: effects of mesostructure and mixed-cell strength treatment

    Science.gov (United States)

    Derrick, J. G.; LaJeunesse, J. W.; Davison, T. M.; Borg, J. P.; Collins, G. S.

    2018-04-01

    The shock response of granular materials is important in a variety of contexts but the precise dynamics of grains during compaction is poorly understood. Here we use 2D mesoscale numerical simulations of the shock compaction of granular tungsten carbide to investigate the effect of internal structure within the particle bed and ‘stiction’ between grains on the shock response. An increase in the average number of contacts with other particles, per particle, tends to shift the Hugoniot to higher shock velocities, lower particle velocities and lower densities. This shift is sensitive to inter-particle shear resistance. Eulerian shock physics codes approximate friction between, and interlocking of, grains with their treatment of mixed cell strength (stiction) and here we show that this has a significant effect on the shock response. When studying the compaction of particle beds it is not common to quantify the pre-compaction internal structure, yet our results suggest that such differences should be taken into account, either by using identical beds or by averaging results over multiple experiments.

  10. Diagnostics for the National Compact Stellarator Experiment

    International Nuclear Information System (INIS)

    Stratton, B.C.; Johnson, D.; Feder, R.; Fredrickson, E.; Neilson, H.; Takahashi, H.; Zarnstorf, M.; Cole, M.; Goranson, P.; Lazarus, E.; Nelson, B.

    2003-01-01

    The status of planning of the National Compact Stellarator Experiment (NCSX) diagnostics is presented, with the emphasis on resolution of diagnostics access issues and on diagnostics required for the early phases of operation

  11. Initial conditions of radiative shock experiments

    International Nuclear Information System (INIS)

    Kuranz, C. C.; Drake, R. P.; Krauland, C. M.; Marion, D. C.; Grosskopf, M. J.; Rutter, E.; Torralva, B.; Holloway, J. P.; Bingham, D.; Goh, J.; Boehly, T. R.; Sorce, A. T.

    2013-01-01

    We performed experiments at the Omega Laser Facility to characterize the initial, laser-driven state of a radiative shock experiment. These experiments aimed to measure the shock breakout time from a thin, laser-irradiated Be disk. The data are then used to inform a range of valid model parameters, such as electron flux limiter and polytropic γ, used when simulating radiative shock experiments using radiation hydrodynamics codes. The characterization experiment and the radiative shock experiment use a laser irradiance of ∼7 × 10 14 W cm −2 to launch a shock in the Be disk. A velocity interferometer and a streaked optical pyrometer were used to infer the amount of time for the shock to move through the Be disk. The experimental results were compared with simulation results from the Hyades code, which can be used to model the initial conditions of a radiative shock system using the CRASH code

  12. Design of compact piezoelectric transducers for shock wave applications

    Science.gov (United States)

    Dreyer, Thomas; Liebler, Marko; Riedlinger, Rainer E.; Ginter, Siegfried

    2003-10-01

    The application of focused intense sound pulses to treat several orthopedic diseases has gained in importance during the past years. Self-focusing piezoelectric transducers known from ESWL are not well suited for this purpose due to their size. Therefore compact transducers have to be designed. This implies an increase of the pressure pulse amplitude generated at the radiating surface. A stacked placement of two piezoelectric layers driven by two high-voltage pulses with an adjustable delay accomplishes this. Several designs are presented here representing transducers of different sizes. In principle piezoelectric transducers have the ability to vary the pressure pulse shape to a wider extent than other shock wave sources. Based on FEM simulations of the transducer the influence of some driving parameters, like a variation of the interpulse delay or shape of the driving voltage, on the resulting focal pressure signal is demonstrated. The results show the feasibility to control some parameters of the signal, for example the peak negative pressure amplitude. This possibility could provide new aspects in basic research as well as in clinical applications.

  13. Structure, phase content and mechanical properties of aluminium with hard particles after shock-wave compaction

    International Nuclear Information System (INIS)

    Kulkov, S; Vorozhtsov, S; Turuntaev, I

    2015-01-01

    The possibilities to combine metal and metal oxide powders in various compositions open a broad range of mechanical and thermal behavior. When using in nanostructured components the resulting materials might exhibit even more interesting properties, like product effectiveness, tensile strength, wear resistance, endurance and corrosion resistance. Intermetallics like TiAl could be obtained as TiAl x in a quality similar to that obtained from melting where only eutectic mixture can be produced. Similar effects are possible when compacting nanoceramic powders whereas these can be combined with intermetallics. Currently, it is very difficult to produce wires and special shaped parts from high temperature superconducting materials. The compacting by explosives could solve this problem.The present paper uses explosion compacting of Al nanoparticles to create nanocomposite with increased physico-mechanical properties. Russian civil explosive Uglenit was chosen as high energy material (HEM) for shock-wave compaction. The different schemes and conditions were suggested to run the explosion process. Al nanoparticles as produced by electric wire explosion contain 8-10% of aluminum oxide. That aluminum oxide can serve as strengthening material in the final nanocomposite which may be generated in various compositions by explosive compacting. Further modifications of nanocomposites were obtained when including nanodiamonds into the mixture with aluminum nanoparticles with different percentages. The addition of nanodiamonds results in a substantial strengthening effect.The experiments with compacting aluminum nanoparticles by explosives are described in detail including the process variations and conditions. The physico-mechanical properties of the nanocomposites are determined and discussed by considering the applied conditions. Especially, microstructure and phases of the obtained nanocomposites are analyzed by X-ray diffraction. (paper)

  14. Structure, phase content and mechanical properties of aluminium with hard particles after shock-wave compaction

    Science.gov (United States)

    Kulkov, S.; Vorozhtsov, S.; Turuntaev, I.

    2015-04-01

    The possibilities to combine metal and metal oxide powders in various compositions open a broad range of mechanical and thermal behavior. When using in nanostructured components the resulting materials might exhibit even more interesting properties, like product effectiveness, tensile strength, wear resistance, endurance and corrosion resistance. Intermetallics like TiAl could be obtained as TiAlx in a quality similar to that obtained from melting where only eutectic mixture can be produced. Similar effects are possible when compacting nanoceramic powders whereas these can be combined with intermetallics. Currently, it is very difficult to produce wires and special shaped parts from high temperature superconducting materials. The compacting by explosives could solve this problem.The present paper uses explosion compacting of Al nanoparticles to create nanocomposite with increased physico-mechanical properties. Russian civil explosive Uglenit was chosen as high energy material (HEM) for shock-wave compaction. The different schemes and conditions were suggested to run the explosion process. Al nanoparticles as produced by electric wire explosion contain 8-10% of aluminum oxide. That aluminum oxide can serve as strengthening material in the final nanocomposite which may be generated in various compositions by explosive compacting. Further modifications of nanocomposites were obtained when including nanodiamonds into the mixture with aluminum nanoparticles with different percentages. The addition of nanodiamonds results in a substantial strengthening effect. The experiments with compacting aluminum nanoparticles by explosives are described in detail including the process variations and conditions. The physico-mechanical properties of the nanocomposites are determined and discussed by considering the applied conditions. Especially, microstructure and phases of the obtained nanocomposites are analyzed by X-ray diffraction.

  15. Pressurized-thermal-shock experiments

    International Nuclear Information System (INIS)

    Whitman, G.D.; McCulloch, R.W.

    1982-01-01

    The primary objective of the ORNL pressurized-thermal-shock (PTS) experiments is to verify analytical methods that are used to predict the behavior of pressurized-water-reactor vessels under these accident conditions involving combined pressure and thermal loading. The criteria on which the experiments are based are: scale large enough to attain effective flaw border triaxial restraint and a temperature range sufficiently broad to produce a progression from frangible to ductile behavior through the wall at a given time; use of materials that can be completely characterized for analysis; stress states comparable to the actual vessel in zones of potential flaw extension; range of behavior to include cleavage initiation and arrest, cleavage initiation and arrest on the upper shelf, arrest in a high K/sub I/ gradient, warm prestressing, and entirely ductile behavior; long and short flaws with and without stainless steel cladding; and control of loads to prevent vessel burst, except as desired. A PTS test facility is under construction which will enable the establishment and control of wall temperature, cooling rate, and pressure on an intermediate test vessel (ITV) in order to simulate stress states representative of an actual reactor pressure vessel

  16. Compact or spread-out cities: Urban planning, taxation, and the vulnerability to transportation shocks

    International Nuclear Information System (INIS)

    Gusdorf, Francois; Hallegatte, Stephane

    2007-01-01

    This paper shows that cities made more compact by transportation taxation are more robust than spread-out cities to shocks in transportation costs. Such a shock, indeed, entails negative transition effects that are caused by housing infrastructure inertia and are magnified in low-density cities. Distortions due to a transportation tax, however, have in absence of shock detrimental consequences that need to be accounted for. The range of beneficial tax levels can, therefore, be identified as a function of the possible magnitude of future shocks in transportation costs. These taxation levels, which can reach significant values, reduce city vulnerability and prevent lock-ins in under-optimal situations

  17. Summary of US compact torus experiments

    International Nuclear Information System (INIS)

    Hartman, C.W.

    1981-01-01

    During the past several years a rapid increase has occurred in compact torus (CT) research in the United States, reflecting renewed interest in this simplified reactor consequences of this configuration. This paper reviews early approaches to CT formation and results and summarizes present experimental studies. Recent experiments have demonstrated a number of macroscopic aspects of the CT, including the conditions under which a macroscopically stable CT can be formed and maintained. Scaling experiments and more detailed studies of plasma transport in progress are discussed along with experiments under construction

  18. Barrier experiment: Shock initiation under complex loading

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-12

    The barrier experiments are a variant of the gap test; a detonation wave in a donor HE impacts a barrier and drives a shock wave into an acceptor HE. The question we ask is: What is the trade-off between the barrier material and threshold barrier thickness to prevent the acceptor from detonating. This can be viewed from the perspective of shock initiation of the acceptor subject to a complex pressure drive condition. Here we consider key factors which affect whether or not the acceptor undergoes a shock-to-detonation transition. These include the following: shock impedance matches for the donor detonation wave into the barrier and then the barrier shock into the acceptor, the pressure gradient behind the donor detonation wave, and the curvature of detonation front in the donor. Numerical simulations are used to illustrate how these factors affect the reaction in the acceptor.

  19. Analysis of Z Pinch Shock Wave Experiments

    International Nuclear Information System (INIS)

    Asay, James; Budge, Kent G.; Chandler, Gordon; Fleming, Kevin; Hall, Clint; Holland, Kathleen; Konrad, Carl; Lawrence, Jeffery; Trott, Wayne; Trucano, Timothy

    1999-01-01

    In this paper, we report details of our computational study of two shock wave physics experiments performed on the Sandia Z machine in 1998. The novelty of these particular experiments is that they represent the first successful application of VISAR interferometry to diagnose shock waves generated in experimental payloads by the primary X-ray pulse of the machine. We use the Sandia shock-wave physics code ALEGRA to perform the simulations reported in this study. Our simulations are found to be in fair agreement with the time-resolved VISAR experimental data. However, there are also interesting and important discrepancies. We speculate as to future use of time-resolved shock wave data to diagnose details of the Z machine X-ray pulse in the future

  20. Advances in NIF Shock Timing Experiments

    Science.gov (United States)

    Robey, Harry

    2012-10-01

    Experiments are underway to tune the shock timing of capsule implosions on the National Ignition Facility (NIF). These experiments use a modified cryogenic hohlraum geometry designed to precisely match the performance of ignition hohlraums. The targets employ a re-entrant Au cone to provide optical access to multiple shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of all four shocks is diagnosed with VISAR (Velocity Interferometer System for Any Reflector). Experiments are now routinely conducted in a mirrored keyhole geometry, which allows for simultaneous diagnosis of the shock timing at both the hohlraum pole and equator. Further modifications are being made to improve the surrogacy to ignition hohlraums by replacing the standard liquid deuterium (D2) capsule fill with a deuterium-tritium (DT) ice layer. These experiments will remove any possible surrogacy difference between D2 and DT as well as incorporate the physics of shock release from the ice layer, which is absent in current experiments. Experimental results and comparisons with numerical simulation are presented.

  1. Theory and Experiment on Radiative Shocks

    Science.gov (United States)

    Drake, R. Paul

    2005-07-01

    The current generation of high-energy-density research facilities has enabled the beginnings of experimental studies of radiation hydrodynamic systems, common in astrophysics but difficult to produce in the laboratory. Radiative shock experiments specifically have been a topic of increasing effort in recent years. Our group and collaborators [1] have emphasized the radiographic observation of structure in radiative shocks. These shocks have been produced on the Omega laser by driving a Be piston through Xenon at velocities above 100 km/s. The talk will summarize these experiments and their results. Interpreting these and other experiments is hampered by the limited range of assumptions used in published theories, and by the limitations in readily available simulation tools. This has motivated an examination of radiative shock theory [2]. The talk will summarize the key issues and present results for specific cases. [ 1 ] Gail Glendinning, Ted Perry, Bruce Remington, Jim Knauer, Tom Boehly, and other members of the NLUF Experimental Astrophysics Team. Publications: Reighard et al., Phys. Rev. Lett. submitted; Leibrandt, et al., Ap J., in press, Reighard et al., IFSA 03 Proceedings, Amer. Nucl. Soc. (2004). [2] Useful discussions with Dmitri Ryutov and Serge Bouquet. Supported by the NNSA programs via DOE Grants DE-FG52-03NA00064 and DE FG53 2005 NA26014

  2. Physics evaluation of compact tokamak ignition experiments

    International Nuclear Information System (INIS)

    Uckan, N.A.; Houlberg, W.A.; Sheffield, J.

    1985-01-01

    At present, several approaches for compact, high-field tokamak ignition experiments are being considered. A comprehensive method for analyzing the potential physics operating regimes and plasma performance characteristics of such ignition experiments with O-D (analytic) and 1-1/2-D (WHIST) transport models is presented. The results from both calculations are in agreement and show that there are regimes in parameter space in which a class of small (R/sub o/ approx. 1-2 m), high-field (B/sub o/ approx. 8-13 T) tokamaks with aB/sub o/ 2 /q/sub */ approx. 25 +- 5 and kappa = b/a approx. 1.6-2.0 appears ignitable for a reasonable range of transport assumptions. Considering both the density and beta limits, an evaluation of the performance is presented for various forms of chi/sub e/ and chi/sub i/, including degradation at high power and sawtooth activity. The prospects of ohmic ignition are also examined. 16 refs., 13 figs

  3. Plasma engineering assessments of compact ignition experiments

    International Nuclear Information System (INIS)

    Houlberg, W.A.

    1985-01-01

    Confinement, startup sequences, and fast-alpha particle effects are assessed for a class of compact tokamak ignition experiments having high toroidal magnetic fields (8 to 12 T) and high toroidal currents (7 to 10 MA). The uncertainties in confinement scaling are spanned through examples of performance with an optimistic model based on ohmically heated plasmas and a pessimistic model that includes confinement degradation by both auxiliary and alpha heating. The roles of neoclassical resistivity enhancement and sawtooth behavior are also evaluated. Copper toroidal field coils place restrictions on pulse lengths due to resistive heating, so a simultaneous rampup of the toroidal field and plasma current is proposed as a means of compressing the startup phase and lengthening the burn phase. If the ignition window is small, fast-alpha particle physics is restricted to the high-density regime where a short slowing-down time leads to low fast-particle density and pressure contributions. Under more optimistic confinement, a larger ignition margin broadens the range of alpha particle physics that can be addressed. These issues are illustrated through examples of transport simulations for a set of machine parameters called BRAND-X, which typify the designs under study

  4. Plasma engineering assessments of compact ignition experiments

    International Nuclear Information System (INIS)

    Houlberg, W.A.

    1986-01-01

    Confinement, startup sequences, and fast-alpha particle effects are assessed for a class of compact tokamak ignition experiments having high toroidal magnetic fields (8-12 T) and high toroidal currents (7-10 MA). The uncertainties in confinement scaling are spanned through examples of performance with an optimistic model based on ohmically heated plasmas and a pessimistic model that includes confinement degradation by both auxiliary and alpha heating. The roles of neoclassical resistivity enhancement and sawtooth behavior are also evaluated. Copper toroidal field coils place restrictions on pulse lengths due to resistive heating, so a simultaneous rampup of the toroidal field and plasma current is proposed as a means of compressing the startup phase and lengthening the burn phase. If the ignition window is small, fast-alpha particle physics is restricted to the high-density regime where a short slowing-down time leads to low fast-particle density and pressure contributions. Under more optimistic confinement, a larger ignition margin broadens the range of alpha particle physics that can be addressed. These issues are illustrated through examples of transport simulations for a set of machine parameters called BRAND-X, which typify the designs under study

  5. Compact Bell inequalities for multipartite experiments

    OpenAIRE

    Wu, Yu-Chun; Żukowski, Marek; Chen, Jing-Ling; Guo, Guang-Can

    2013-01-01

    A method for construction of the multipartite Clauser-Horne-Shimony-Holt (CHSH) type Bell inequalities, for the case of local binary observables, is presented. The standard CHSH-type Bell inequalities can be obtained as special cases. A unified framework to establish all kinds of CHSH-type Bell inequalities by increasing step by step the number of observers is given. As an application, compact Bell inequalities, for eight observers, involving just four correlation functions are proposed. They...

  6. CT-TRX1, a triggered-reconnection compact toroid experiment

    International Nuclear Information System (INIS)

    Hoffman, A.L.

    1980-05-01

    A new compact toroid experiment, CT-TRX1, based on the field reversed theta pinch is under construction. The unique feature of this experiment is the incorporation of several quasi-steady and pulsed magnets to carefully control the reconnection process. The motivation for this emphasis is to duplicate and extend the results reported by Kurtmullaev, et al., where delayed reconnection produced efficient axial shock heating and resulted in large diameter compact toroids which exhibited complete MHD stability for the 100 μsec decay time of their pulsed magnets. CT-TRX1 incorporates moderate E/sub theta/ radial shock heating, along with the triggered reconnection capability, to investigate the full range of conditions between the USSR experiments and the radial shock heated experiments at LASL, where m = 2 rotational instabilities occur. An additional feature of CT-TRX1 is the incorporation of a compound magnet which will provide long magnetic field decay times. The requirements for both high field quasi-steady outer magnets, and several high voltage, individually triggered pulsed inner magnets, present unique engineering design problems which are discussed

  7. Strain measurements during pressurized thermal shock experiment

    International Nuclear Information System (INIS)

    Tarso Vida Gomes, P. de; Julio Ricardo Barreto Cruz; Tanius Rodrigues Mansur; Denis Henrique Bianchi Scaldaferri; Miguel Mattar Neto

    2005-01-01

    For the life extension of nuclear power plants, the residual life of most of their components must be evaluated along all their operating time. Concerning the reactor pressure vessel, the pressurized thermal shock (PTS) is a very important event to be considered. For better understanding the effects of this kind of event, tests are made. The approach described here consisted of building a simplified in-scale physical model of the reactor pressure vessel, submitting it to the actual operating temperature and pressure conditions and provoking a thermal shock by means of cold water flow in its external surface. To conduct such test, the Nuclear Technology Development Center (CDTN) has been conducting several studies related to PTS and has also built a laboratory that has made possible the simulation of the PTS loading conditions. Several cracks were produced in the external surface of the reactor pressure vessel model. Strain gages were fixed by means of electrical discharge welding over the cracks regions in both external and internal surfaces. The temperature was monitored in 10 points across the vessel wall. The internal pressure was manually controlled and monitored using a pressure transducer. Two PTS experiments were conducted and this paper presents the strain measurement procedures applied to the reactor pressure vessel model, during the PTS, using strain gages experimental methodology. (authors)

  8. Operational experience acquired in radioactive waste compaction

    International Nuclear Information System (INIS)

    Bauer, S.; Mohr, P.; Hempelmann, W.

    1993-01-01

    The low-level radioactive waste scrapping facility in the KfK decontamination division was commissioned in 1983. Non-combustible residues and removed system components of low activity, but which are to be handled and disposed of as radioactive waste are in drums, casks or containers delivered to the facility. The waste usually undergoes pretreatment in a crusher, with the volume being definitively reduced at a pressure of 690 bar in the high-pressure compactor. In 1990, the overhead-crane was refurbished for remote control handling in the scrapping caisson. The parts to undergo scrapping are unpacked in the material lock, and then go into the scrapping caisson. It is possible to use here various mechanical and thermal methods to dismantle the respective parts. But most of the parts to undergo scrapping are such as that it is possible to directly pretreat them in the crusher. The obtained scrap is loaded into 180-liter drums. Most of the machinery in the caisson is manually operated. The operating crew enters the caisson in fully ventilated protective overalls. The drums filled with the scrap then go to the high-pressure compactor in the caisson. The compacts are temporarily stored, until recalled depending on their height and filled into drums such as that optimal drum filling is guaranteed

  9. Counterpropagating Radiative Shock Experiments on the Orion Laser.

    Science.gov (United States)

    Suzuki-Vidal, F; Clayson, T; Stehlé, C; Swadling, G F; Foster, J M; Skidmore, J; Graham, P; Burdiak, G C; Lebedev, S V; Chaulagain, U; Singh, R L; Gumbrell, E T; Patankar, S; Spindloe, C; Larour, J; Kozlova, M; Rodriguez, R; Gil, J M; Espinosa, G; Velarde, P; Danson, C

    2017-08-04

    We present new experiments to study the formation of radiative shocks and the interaction between two counterpropagating radiative shocks. The experiments are performed at the Orion laser facility, which is used to drive shocks in xenon inside large aspect ratio gas cells. The collision between the two shocks and their respective radiative precursors, combined with the formation of inherently three-dimensional shocks, provides a novel platform particularly suited for the benchmarking of numerical codes. The dynamics of the shocks before and after the collision are investigated using point-projection x-ray backlighting while, simultaneously, the electron density in the radiative precursor was measured via optical laser interferometry. Modeling of the experiments using the 2D radiation hydrodynamic codes nym and petra shows very good agreement with the experimental results.

  10. Beta II compact torus experiment plasma equilibrium and power balance

    International Nuclear Information System (INIS)

    Turner, W.C.; Goldenbaum, G.C.; Granneman, E.H.A.; Prono, D.S.; Hartman, C.W.; Taska, J.

    1982-01-01

    In this paper we follow up some of our earlier work that showed the compact torus (CT) plasma equilibrium produced by a magnetized coaxial plasma gun is nearly force free and that impurity radiation plays a dominant role in determining the decay time of plasma currents in present generation experiments

  11. Overview and recent progress of the Magnetized Shock Experiment (MSX)

    Science.gov (United States)

    Weber, T. E.; Intrator, T. P.; Smith, R. J.; Hutchinson, T. M.; Boguski, J. C.; Sears, J. A.; Swan, H. O.; Gao, K. W.; Chapdelaine, L. J.; Winske, D.; Dunn, J. P.

    2013-10-01

    The Magnetized Shock Experiment (MSX) has been constructed to study the physics of super-Alfvènic, supercritical, magnetized shocks. Exhibiting transitional length and time scales much smaller than can be produced through collisional processes, these shocks are observed to create non-thermal distributions, amplify magnetic fields, and accelerate particles to relativistic velocities. Shocks are produced through the acceleration and subsequent stagnation of Field Reversed Configuration (FRC) plasmoids against a high-flux magnetic mirror with a conducting boundary or a plasma target with embedded field. Adjustable shock velocity, density, and magnetic geometry (B parallel, perpendicular, or oblique to k) provide unique access to a wide range of dimensionless parameters relevant to astrophysical shocks. Information regarding the experimental configuration, diagnostics suite, recent simulations, experimental results, and physics goals will be presented. This work is supported by DOE OFES and NNSA under LANS contract DE-AC52-06NA25369 Approved for Public Release: LA-UR-13-24859.

  12. Compaction wave profiles: Simulations of gas gun experiments

    International Nuclear Information System (INIS)

    Menikoff, Ralph

    2001-01-01

    Mesoscale simulations of a compaction wave in a granular bed of HMX have been performed. The grains are fully resolved in order that the compaction, i.e., the porosity behind the wave front, is determined by the elastic-plastic response of the grains rather than by an empirical law for the porosity as a function of pressure. Numerical wave profiles of the pressure and velocity are compared with data from a gas gun experiment. The experiment used an initial porosity of 36%, and the wave had a pressure comparable to the yield strength of the grains. The profiles are measured at the front and back of the granular bed. The transit time for the compaction wave to propagate between the gauges determines the wave speed. The wave speed depends on the porosity behind the wave and is affected by the strength model. The yield strength needed to match the experimental wave speed is discussed. Analysis of the lead wave through the granular bed, based on impedance matches using the Hugoniot loci, indicates that the compaction wave triggers a small amount of burn, less than 1% mass fraction, on the microsecond time scale of the experiment. copyright 2001 American Institute of Physics

  13. Optimal Design of Shock Tube Experiments for Parameter Inference

    KAUST Repository

    Bisetti, Fabrizio; Knio, Omar

    2014-01-01

    We develop a Bayesian framework for the optimal experimental design of the shock tube experiments which are being carried out at the KAUST Clean Combustion Research Center. The unknown parameters are the pre-exponential parameters and the activation

  14. Shock-timing experiments for Inertial Confinement Fusion

    International Nuclear Information System (INIS)

    Debras, G.

    2012-01-01

    The Laser Megajoule (LMJ), which should achieve energy gain in an indirect drive inertial confinement fusion configuration, is being built in France by the CEA (Commissariat a l'Energie Atomique et aux Energies Alternatives). To achieve thermonuclear ignition, the compression of a spherical target will have to be controlled by a series of accurately timed centripetal shocks, with a finely tuned level. A first experiment, performed in 2010 on the LIL (Ligne d'Integration Laser) facility at CEA, has allowed us to study the coalescence of two planar shocks in an indirectly-driven sample of polystyrene, within the framework of shock timing. The main objectives were to validate the experimental concept and the numerical simulations, as a proof-of-principle for future shock-timing campaigns. The main diagnostics used for this study are VISAR (Velocity Interferometer System for Any Reflection) and an optical shock breakout diagnostic, taking into account optical perturbations caused by X-rays. In another experiment, conducted on the LULI (Laboratoire pour l'Utilisation des Lasers Intenses) laser facility in 2010, we studied the timing of two planar directly-driven shocks using the same diagnostics. This latter study is related to the shock ignition concept, with the long-term perspective of energy production. This thesis presents these two experiments and their results. (author) [fr

  15. The Compact Muon Solenoid Experiment at the Large Hadron Collider The Compact Muon Solenoid Experiment at the Large Hadron Collider

    Directory of Open Access Journals (Sweden)

    David Delepine

    2012-02-01

    Full Text Available The Compact Muon Solenoid experiment at the CERN Large Hadron Collider will study protonproton collisions at unprecedented energies and luminosities. In this article we providefi rst a brief general introduction to particle physics. We then explain what CERN is. Thenwe describe the Large Hadron Collider at CERN, the most powerful particle acceleratorever built. Finally we describe the Compact Muon Solenoid experiment, its physics goals,construction details, and current status.El experimento Compact Muon Solenoid en el Large Hadron Collider del CERN estudiarácolisiones protón protón a energías y luminosidades sin precedente. En este artículo presentamos primero una breve introducción general a la física de partículas. Despuésexplicamos lo que es el CERN. Luego describimos el Large Hadron Collider, el más potente acelerador de partículas construido por el hombre, en el CERN. Finalmente describimos el experimento Compact Muon Solenoid, sus objetivos en física, los detalles de su construcción,y su situación presente.

  16. Shock-hydrodynamics experiments on the Nova laser

    International Nuclear Information System (INIS)

    Miller, P.; Peyser, T.; Stry, P.; Budil, K.; Wojtowicz, D.; Burke, E.

    1995-08-01

    We have conducted shock-induced hydrodynamics experiments using the Nova laser at Lawrence Livermore National Laboratory. The laser provides a high-enthalpy source by depositing its energy (about 22 kJ) in a small gold cavity called a Hohlraum. The Hohlraum serves as a driver section, launching very strong (M ∼ 20) shocks into millimeter-scale cylindrical ''shock tubes.'' The flow is imaged radiographically by an electronic framing camera, using a laser-generated x-ray source. Several topics have been addressed with this configuration, including shock-induced mixing at density interfaces (seeded with a variety of perturbations); the development of high-speed, shaped-charge-like jets; the effects of geometry on the planarity of the generated shocks; and shock-shock interactions which develop in the flows. This paper describes the general configuration of our experiments, presents an overview of the high-speed jet work, discusses some of our findings, and compares our results with computer simulations

  17. High-power laser experiments to study collisionless shock generation

    Directory of Open Access Journals (Sweden)

    Sakawa Y.

    2013-11-01

    Full Text Available A collisionless Weibel-instability mediated shock in a self-generated magnetic field is studied using two-dimensional particle-in-cell simulation [Kato and Takabe, Astophys. J. Lett. 681, L93 (2008]. It is predicted that the generation of the Weibel shock requires to use NIF-class high-power laser system. Collisionless electrostatic shocks are produced in counter-streaming plasmas using Gekko XII laser system [Kuramitsu et al., Phys. Rev. Lett. 106, 175002 (2011]. A NIF facility time proposal is approved to study the formation of the collisionless Weibel shock. OMEGA and OMEGA EP experiments have been started to study the plasma conditions of counter-streaming plasmas required for the NIF experiment using Thomson scattering and to develop proton radiography diagnostics.

  18. Component Manufacturing Development for the National Compact Stellarator Experiment (NCSX)

    International Nuclear Information System (INIS)

    Heitzenroeder, P.J.; Brown, T.G.; Chrzanowski, J.H.; Cole, M.J.; Goranson, P.L.; Neilson, G.H.; Nelson, B.E.; Reiersen, W.T.; Sutton, L.L.; Williamson, D.E.; Viola, M.E.

    2004-11-01

    NCSX [National Compact Stellarator Experiment] is the first of a new class of stellarators called compact stellarators which hold the promise of retaining the steady state feature of the stellarator but at a much lower aspect ratio and using a quasi-axisymmetric magnetic field to obtain tokamak-like performance. Although much of NCSX is conventional in design and construction, the vacuum vessel and modular coils provide significant engineering challenges due to their complex shapes, need for high dimensional accuracy, and the high current density required in the modular coils due space constraints. Consequently, a three-phase development program has been undertaken. In the first phase, laboratory/industrial studies were performed during the development of the conceptual design to permit advances in manufacturing technology to be incorporated into NCSX's plans. In the second phase, full-scale prototype modular coil winding forms, compacted cable conductors, and 20 degree sectors of the vacuum vessel were fabricated in industry. In parallel, the NCSX project team undertook RandD studies that focused on the windings. The third (production) phase began in September 2004. First plasma is scheduled for January 2008

  19. The Transitional Experience: An Alternative View of Culture Shock

    Science.gov (United States)

    Adler, Peter S.

    1975-01-01

    This article contended that the problems and frustrations encountered in the culture shock process are important to an understanding of change and movement experiences, and that such transitional experiences can be the source of higher levels of personality development. (Author/RK)

  20. Advances in shock timing experiments on the National Ignition Facility

    International Nuclear Information System (INIS)

    Robey, H F; Celliers, P M; Moody, J D; Sater, J; Parham, T; Kozioziemski, B; Dylla- Spears, R; Ross, J S; LePape, S; Ralph, J E; Hohenberger, M; Dewald, E L; Berzak Hopkins, L; Kroll, J J; Yoxall, B E; Hamza, A V; Landen, O L; Edwards, M J; Boehly, T R; Nikroo, A

    2016-01-01

    Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion (ICF) implosions were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique. (paper)

  1. Advances in shock timing experiments on the National Ignition Facility

    Science.gov (United States)

    Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R.; Ross, J. S.; LePape, S.; Ralph, J. E.; Hohenberger, M.; Dewald, E. L.; Berzak Hopkins, L.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Boehly, T. R.; Nikroo, A.; Landen, O. L.; Edwards, M. J.

    2016-03-01

    Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion (ICF) implosions were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique.

  2. Shock timing on the National Ignition Facility: First experiments

    Directory of Open Access Journals (Sweden)

    Celliers P.M.

    2013-11-01

    Full Text Available An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a re-entrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

  3. Pyro shock simulation: Experience with the MIPS simulator

    Science.gov (United States)

    Dwyer, Thomas J.; Moul, David S.

    1988-01-01

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

  4. Shock timing on the National Ignition Facility: First Experiments

    International Nuclear Information System (INIS)

    Celliers, P.M.; Robey, H.F.; Boehly, T.R.; Alger, E.; Azevedo, S.; Berzins, L.V.; Bhandarkar, S.D.; Bowers, M.W.; Brereton, S.J.; Callahan, D.; Castro, C.; Chandrasekaran, H.; Choate, C.; Clark, D.; Coffee, K.R.; Datte, P.S.; Dewald, E.L.; DiNicola, P.; Dixit, S.; Doeppner, T.; Dzenitis, E.; Edwards, M.J.; Eggert, J.H.; Fair, J.; Farley, D.R.; Frieders, G.; Gibson, C.R.; Giraldez, E.; Haan, S.; Haid, B.; Hamza, A.V.; Haynam, C.; Hicks, D.G.; Holunga, D.M.; Horner, J.B.; Jancaitis, K.; Jones, O.S.; Kalantar, D.; Kline, J.L.; Krauter, K.G.; Kroll, J.J.; LaFortune, K.N.; Pape, S.L.; Malsbury, T.; Maypoles, E.R.; Milovich, J.L.; Moody, J.D.; Moreno, K.; Munro, D.H.; Nikroo, A.; Olson, R.E.; Parham, T.; Pollaine, S.; Radousky, H.B.; Ross, G.F.; Sater, J.; Schneider, M.B.; Shaw, M.; Smith, R.F.; Thomas, C.A.; Throop, A.; Town, R.J.; Trummer, D.; Van Wonterghem, B.M.; Walters, C.F.; Widmann, K.; Widmayer, C.; Young, B.K.; Atherton, L.J.; Collins, G.W.; Landen, O.L.; Lindl, J.D.; MacGowan, B.J.; Meyerhofer, D.D.; Moses, E.I.

    2011-01-01

    An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a reentrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

  5. Optical diagnostics on the Magnetized Shock Experiment (MSX)

    Science.gov (United States)

    Boguski, J. C.; Weber, T. E.; Intrator, T. P.; Smith, R. J.; Dunn, J. P.; Hutchinson, T. M.; Gao, K. W.

    2013-10-01

    The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory was built to investigate the physics of high Alfvén Mach number, supercritical, magnetized shocks through the acceleration and subsequent stagnation of a Field Reversed Configuration (FRC) plasmoid against a magnetic mirror and/or plasma target. A suite of optical diagnostics has recently been fielded on MSX to characterize plasma conditions during the formation, acceleration, and stagnation phases of the experiment. CCD-backed streak and framing cameras, and a fiber-based visible light array, provide information regarding FRC shape, velocity, and instability growth. Time-resolved narrow and broadband spectroscopy provides information on pre-shock plasma temperature, impurity levels, shock location, and non-thermal ion distributions within the shock region. Details of the diagnostic design, configuration, and characterization will be presented along with initial results. This work is supported by the Center for Magnetic Self Organization, DoE OFES and NNSA under LANS contract DE-AC52-06NA25369. Approved for public release: LA-UR- 13-25190.

  6. Explosive compaction of aluminum oxide modified by multiwall carbon nanotubes

    Science.gov (United States)

    Buzyurkin, A. E.; Kraus, E. I.; Lukyanov, Ya L.

    2018-04-01

    This paper presents experiments and numerical research on explosive compaction of aluminum oxide powder modified by multiwall carbon nanotubes (MWCNT) and modeling of the stress state behind the shock front at shock loading. The aim of this study was to obtain a durable low-porosity compact sample. The explosive compaction technology is used in this problem because the aluminum oxide is an extremely hard and refractory material. Therefore, its compaction by traditional methods requires special equipment and considerable expenses.

  7. Pressurized-thermal-shock experiments with thick vessels

    International Nuclear Information System (INIS)

    Bryan, R.H.; Nanstad, R.K.; Merkle, J.G.; Robinson, G.C.; Whitman, G.D.

    1986-01-01

    Information is provided on the series of pressurized-thermal-shock experiments at the Oak Ridge National Laboratory, motivated by a concern for the behavior of flaws in reactor pressure vessels having welds or shells exhibiting low upper-shelf Charpy impact energies, approx. 68J or less

  8. Physics Design of the National Compact Stellarator Experiment

    International Nuclear Information System (INIS)

    Neilson, G.H.; Zarnstorff, M.C.; Lyon, J.F.

    2002-01-01

    Compact quasi-axisymmetric stellarators offer the possibility of combining the steady-state low-recirculating power, external control, and disruption resilience of previous stellarators with the low-aspect ratio, high beta-limit, and good confinement of advanced tokamaks. Quasi-axisymmetric equilibria have been developed for the proposed National Compact Stellarator Experiment (NCSX) with average aspect ratio approximately 4.4 and average elongation approximately 1.8. Even with bootstrap-current consistent profiles, they are passively stable to the ballooning, kink, vertical, Mercier, and neoclassical-tearing modes for b > 4%, without the need for external feedback or conducting walls. The bootstrap current generates only 1/4 of the magnetic rotational transform at b = 4% (the rest is from the coils). Transport simulations show adequate fast-ion confinement and thermal neoclassical transport similar to equivalent tokamaks. Modular coils have been designed which reproduce the physics properties, provide good flux surfaces, and allow flexible variation of the plasma shape to control the predicted MHD stability and transport properties

  9. Mechanic- and hydraulic shock-absorbers - layout, construction, operation experience

    International Nuclear Information System (INIS)

    Kluge, M.

    1981-01-01

    The problem lies in the protection of the flexible supported power plant components against undesired sudden movements. Various shock absorbing systems are at disposal in this case: Mechanical and hydraulic shock absorbers, whose functioning systems are shown in figures. The operation experience showed a series of deficiencies, as demonstrated on various figures. In order to avoid them, some important recommendations are given. Requirements and layout are demonstrated according to todays' state-of-the-art. The admissible stresses, resulting from the summary of various specifications for the analytical evidence will be described. Development and construction will be explained in detail by means of pictures with cross sections of original shock absorbers. Todays' construction characteristics will be summarized. The final remark includes a request for generally valid guidelines. (orig.) [de

  10. Planar radiative shock experiments and their comparison to simulations

    International Nuclear Information System (INIS)

    Reighard, A. B.; Drake, R. P.; Mucino, J. E.; Knauer, J. P.; Busquet, M.

    2007-01-01

    Recent experiments have obtained radiographic data from shock waves driven at >100 km/s in xenon gas, and Thomson scattering data from similar experiments using argon gas. Presented here is a review of these experiments, followed by an outline of the discrepancies between the data and the results of one-dimensional simulations. Simulations using procedures that work well for similar but nonradiative experiments show inconsistencies between the measured position of the interface of the beryllium and xenon and the calculated position for these experiments. Sources of the discrepancy are explored

  11. Optimal Design of Shock Tube Experiments for Parameter Inference

    KAUST Repository

    Bisetti, Fabrizio

    2014-01-06

    We develop a Bayesian framework for the optimal experimental design of the shock tube experiments which are being carried out at the KAUST Clean Combustion Research Center. The unknown parameters are the pre-exponential parameters and the activation energies in the reaction rate expressions. The control parameters are the initial mixture composition and the temperature. The approach is based on first building a polynomial based surrogate model for the observables relevant to the shock tube experiments. Based on these surrogates, a novel MAP based approach is used to estimate the expected information gain in the proposed experiments, and to select the best experimental set-ups yielding the optimal expected information gains. The validity of the approach is tested using synthetic data generated by sampling the PC surrogate. We finally outline a methodology for validation using actual laboratory experiments, and extending experimental design methodology to the cases where the control parameters are noisy.

  12. Diagnostics Plan for the National Compact Stellarator Experiment

    International Nuclear Information System (INIS)

    D. Johnson; T. Brown; H. Neilson; G. Schilling; H. Takahashi; M. Zarnstorff; M. Cole; E. Lazarus; and M. Fenstermacher

    2002-01-01

    The National Compact Stellarator Experiment (NCSX) is a stellarator-tokamak hybrid seeking to combine the good confinement, high beta and moderate aspect ratio of the tokamak with the quasi-steady-state operation and good stability properties of the stellarator. A preliminary list of measurement requirements, intended to satisfy the needs of the phased research plan, provides the basis for a full complement of plasma diagnostics. It is important to consider this full set, even at this early stage, to assess the adequacy of the stellarator design for diagnostic port access. The 3-D nature of the plasma is a measurement challenge, as is the necessity for high spatial resolution to assess the quality of magnetic surfaces. Other diagnostic requirements include the need for re-entrant views that penetrate the cryostat, for a convenient e-beam probe for field line mapping, and for a diagnostic neutral beam for active spectroscopy

  13. Plasma boundary considerations for the national compact stellarator experiment

    International Nuclear Information System (INIS)

    Mioduszewski, P.; Grossman, A.; Fenstermacher, M.; Koniges, A.; Owen, L.; Rognlien, T.; Umansky, M.

    2003-01-01

    The national compact stellarator experiment (NCSX) [EPS 2001, Madeira, Portugal, 18-22 June 2001] is a new fusion project located at Princeton Plasma Physics Laboratory, Princeton, NJ. Plasma boundary control in stellarators has been shown to be very effective in improving plasma performance [EPS 2001, Madeira, Portugal, 18-22 June 2001] and, accordingly, will be an important element from the very beginning of the NCSX design. Plasma-facing components will be developed systematically according to our understanding of the NCSX boundary, with the eventual goal to develop a divertor with all the benefits for impurity and neutrals control. Neutrals calculations have been started to investigate the effect of neutrals penetration at various cross-sections

  14. Effects of expanding compact H II regions upon molecular clouds: Molecular dissociation waves, shock waves, and carbon ionization

    International Nuclear Information System (INIS)

    Hill, J.K.; Hollenbach, D.J.

    1978-01-01

    The effect of young expanding compact H II regions upon their molecular environments are studied, emphasizing the simultaneous evolution of the molecular hydrogen dissociation front and the shocked shell of gas surrounding the nebula. For H II regions powered by 05 stars embedded in molecular clouds of ambient density 10 3 -10 4 cm -3 the dissociation wave initially travels outward much more rapidly than the shock, but later decelerates and is swept up by the shock about 10 5 yr after the expansion begins. The 21 cm line of atomic hydrogen will be optically thick in both the preshock and postshock gas for most of this period. The most important coolant transitions are the [O I] 63 μm line and, for t> or approx. =10 5 yr, the rotational transitions of H 2 and/or the rotational transitions of CO. The vibrational transitions of H 2 are excited predominantly by ultraviolet pumping. We estimate the preshock and postshock carbon recombination-line emission measures

  15. Managing reality shock: Expectations versus experiences of graduate engineers

    Directory of Open Access Journals (Sweden)

    Sarah Riordan

    2007-10-01

    Full Text Available The objective of the study is an analysis of the relationship between the work expectations and experiences of graduate engineers during their early career period. It reports on discrepancies in graduates’ expectations of the world of work and the reality of the early career stage. Conclusions include recommendations of how "reality shock" can be managed better by both organisations and individuals. Qualitative data were obtained through in-depth interviews with sixteen participants with less than five years work experience, employed in a large utility organisation in the Western Cape. Results indicate that participants experience significant incongruence between their expectations of work and work experiences.

  16. Field-reversed experiments (FRX) on compact toroids

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-11-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10/sup 15/ cm/sup -3/ to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10/sup 15/ cm/sup -3/. Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 ..mu..sec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed.

  17. Field-reversed experiments (FRX) on compact toroids

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-01-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10 15 cm -3 to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10 15 cm -3 . Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 μsec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed

  18. Systems Analysis of a Compact Next Step Burning Plasma Experiment

    International Nuclear Information System (INIS)

    Jardin, S.C.; Kessel, C.E.; Meade, D.; Neumeyer, C.

    2002-01-01

    A new burning plasma systems code (BPSC) has been developed for analysis of a next step compact burning plasma experiment with copper-alloy magnet technology. We consider two classes of configurations: Type A, with the toroidal field (TF) coils and ohmic heating (OH) coils unlinked, and Type B, with the TF and OH coils linked. We obtain curves of the minimizing major radius as a function of aspect ratio R(A) for each configuration type for typical parameters. These curves represent, to first order, cost minimizing curves, assuming that device cost is a function of major radius. The Type B curves always lie below the Type A curves for the same physics parameters, indicating that they lead to a more compact design. This follows from that fact that a high fraction of the inner region, r < R-a, contains electrical conductor material. However, the fact that the Type A OH and TF magnets are not linked presents fewer engineering challenges and should lead to a more reliable design. Both the Type A and Type B curves have a minimum in major radius R at a minimizing aspect ratio A typically above 2.8 and at high values of magnetic field B above 10 T. The minimizing A occurs at larger values for longer pulse and higher performance devices. The larger A and higher B design points also have the feature that the ratio of the discharge time to the current redistribution time is largest so that steady-state operation can be more realistically prototyped. A sensitivity study is presented for the baseline Type A configuration showing the dependence of the results on the parameters held fixed for the minimization study

  19. Magnetic Diagnostics on the Magnetized Shock Experiment (MSX)

    Science.gov (United States)

    Hutchinson, T. M.; Weber, T. E.; Boguski, J. C.; Intrator, T. P.; Smith, R. J.; Dunn, J. P.

    2013-10-01

    The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory was built to investigate the physics of high-Alfvénic, supercritical, magnetized shocks through the acceleration and subsequent stagnation of a Field Reversed Configuration (FRC) plasmoid against a magnetic mirror and/or plasma target. An array of high-bandwidth, multi-axis, robust, internal magnetic probes has been constructed to characterize flux compression ratios, instability formation, and turbulent macro-scale features of the post-shock plasma. The mirror magnet is mounted on a linear translation stage, providing a capability to axially move the shock layer through the probe field of view. An independent, external probe array also provides conventional information on the FRC shape, velocity, and total pressure during the formation and acceleration phases. Probe design, characterization, configuration, and initial results are presented. This work is supported by the DOE OFES and NNSA under LANS contract DE-AC52-06NA25369. LA-UR-13-25189.

  20. Thermodynamic model of the compaction of powder materials by shock waves

    NARCIS (Netherlands)

    Dijken, Durandus; Hosson, J.Th.M. De

    1994-01-01

    For powder materials a model is proposed to predict the mean temperature behind the shock wave, the ratio between the increase of thermal energy and increase of total internal energy, as well as the mean final temperature after release of adiabatic pressure. Further, the change of pressure, specific

  1. Collisionless shock experiments with lasers and observation of Weibel instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.-S., E-mail: park1@llnl.gov; Huntington, C. M.; Fiuza, F.; Levy, M. C.; Pollock, B. B.; Remington, B. A.; Ross, J. S.; Ryutov, D. D.; Turnbull, D. P.; Weber, S. V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Drake, R. P.; Kuranz, C. C. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Froula, D. H.; Rosenberg, M. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States); Gregori, G.; Meinecke, J. [University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Koenig, M. [LULI, Ecole Polytechnique, Palaiseau (France); Kugland, N. L. [Lam Research Corporation, Fremont, California 94538 (United States); Lamb, D. Q.; Tzeferacos, P. [University of Chicago, Chicago, California 94538 (United States); and others

    2015-05-15

    Astrophysical collisionless shocks are common in the universe, occurring in supernova remnants, gamma ray bursts, and protostellar jets. They appear in colliding plasma flows when the mean free path for ion-ion collisions is much larger than the system size. It is believed that such shocks could be mediated via the electromagnetic Weibel instability in astrophysical environments without pre-existing magnetic fields. Here, we present laboratory experiments using high-power lasers and investigate the dynamics of high-Mach-number collisionless shock formation in two interpenetrating plasma streams. Our recent proton-probe experiments on Omega show the characteristic filamentary structures of the Weibel instability that are electromagnetic in nature with an inferred magnetization level as high as ∼1% [C. M. Huntington et al., “Observation of magnetic field generation via the weibel instability in interpenetrating plasma flows,” Nat. Phys. 11, 173–176 (2015)]. These results imply that electromagnetic instabilities are significant in the interaction of astrophysical conditions.

  2. Overview and recent results of the Magnetized Shock Experiment (MSX)

    Science.gov (United States)

    Weber, T. E.; Smith, R. J.; Hsu, S. C.; Omelchenko, Y.

    2015-11-01

    Recent machine and diagnostics upgrades to the Magnetized Shock Experiment (MSX) at LANL have enabled unprecedented access to the physical processes arising from stagnating magnetized (β ~ 1), collisionless, highly supersonic (M ,MA ~ 10) flows, similar in dimensionless parameters to those found in both space and astrophysical shocks. Hot (100s of eV during translation), dense (1022 - 1023 m-3) Field Reversed Configuration (FRC) plasmoids are accelerated to high velocities (100s of km/s) and subsequently impact against a static target such as a strong parallel or anti-parallel (reconnection-wise) magnetic mirror, a solid obstacle, or neutral gas cloud to recreate the physics of interest with characteristic length and time scales that are both large enough to observe yet small enough to fit within the experiment. Long-lived (>50 μs) stagnated plasmas with density enhancement much greater than predicted by fluid theory (>4x) are observed, accompanied by discontinuous plasma structures indicating shocks and jetting (visible emission and interferometry) and copious >1 keV x-ray emission. An overview of the experimental program will be presented, including machine design and capabilities, diagnostics, and an examination of the physical processes that occur during stagnation against a variety of targets. Supported by the DOE Office of Fusion Energy Sciences under contract DE-AC52-06NA25369.

  3. Overview, Progress, and Plans for the Compact Toroidal Hybrid Experiment

    Science.gov (United States)

    Hartwell, G. J.; Allen, N. R.; Ennis, D. A.; Hanson, J. D.; Howell, E. C.; Johnson, C. A.; Knowlton, S. F.; Kring, J. D.; Ma, X.; Maurer, D. A.; Ross, K. G.; Schmitt, J. C.; Traverso, P. J.; Williamson, E. N.

    2017-10-01

    The Compact Toroidal Hybrid (CTH) is an l = 2 , m = 5 torsatron/tokamak hybrid (R0 = 0.75 m, ap 0.2 m, and | B | disruption studies. The main goals of the CTH experiment are to study disruptive behavior as a function of applied 3D magnetic shaping, and to test and advance the V3FIT reconstruction code and NIMROD modeling of CTH. The disruptive density limit is observed to exceed the Greenwald limit as the vacuum transform is increased with no observed threshold for avoidance. Low-q operations (1.1 routine, with disruptions ceasing if the vacuum transform is raised above 0.07. Sawteeth are observed in CTH and have a similar phenomenology to tokamak sawteeth despite employing a 3D confining field. Application of vacuum transform has been demonstrated to reduce and eliminate the vertical drift of elongated discharges. Internal SXR diagnostics, in conjunction with external magnetics, extend the range of reconstruction accuracy into the plasma core. This work is supported by U.S. Department of Energy Grant No. DE-FG02-00ER54610.

  4. Shock compression experiments on Lithium Deuteride single crystals.

    Energy Technology Data Exchange (ETDEWEB)

    Knudson, Marcus D.; Desjarlais, Michael Paul; Lemke, Raymond W.

    2014-10-01

    S hock compression exper iments in the few hundred GPa (multi - Mabr) regime were performed on Lithium Deuteride (LiD) single crystals . This study utilized the high velocity flyer plate capability of the Sandia Z Machine to perform impact experiments at flyer plate velocities in the range of 17 - 32 km/s. Measurements included pressure, density, and temperature between %7E200 - 600 GPa along the Principal Hugoniot - the locus of end states achievable through compression by large amplitude shock waves - as well as pressure and density of re - shock states up to %7E900 GPa . The experimental measurements are compared with recent density functional theory calculations as well as a new tabular equation of state developed at Los Alamos National Labs.

  5. Design, Construction, Alignment, and Calibration of a Compact Velocimetry Experiment

    International Nuclear Information System (INIS)

    Morris I Kaufman; Robert M Malone; Brent C Frogget; David L Esquibel; Vincent T Romero; Gregory A Lare; Bart Briggs; Adam J Iverson; Daniel K Frayer; Douglas DeVore Brian Cata

    2007-01-01

    A velocimetry experiment has been designed to measure shock properties for small cylindrical metal targets (8-mm-diameter by 2-mm thick). A target is accelerated by high explosives, caught, and retrieved for later inspection. The target is expected to move at a velocity of 0.1 to 3 km/sec. The complete experiment canister is approximately 105 mm in diameter and 380 mm long. Optical velocimetry diagnostics include the Velocity Interferometer System for Any Reflector (VISAR) and Photon Doppler Velocimetry (PDV). The packaging of the velocity diagnostics is not allowed to interfere with the catchment or an X-ray imaging diagnostic. A single optical relay, using commercial lenses, collects Doppler-shifted light for both VISAR and PDV. The use of fiber optics allows measurement of point velocities on the target surface during accelerations occurring over 15 mm of travel. The VISAR operates at 532 nm and has separate illumination fibers requiring alignment. The PDV diagnostic operates at 1550 nm, but is aligned and focused at 670 nm. The VISAR and PDV diagnostics are complementary measurements and they image spots in close proximity on the target surface. Because the optical relay uses commercial glass, the axial positions of the optical fibers for PDV and VISAR are offset to compensate for chromatic aberrations. The optomechanical design requires careful attention to fiber management, mechanical assembly and disassembly, positioning of the foam catchment, and X-ray diagnostic field-of-view. Calibration and alignment data are archived at each stage of the assembly sequence

  6. Computational study of the interaction between a shock and a near-wall vortex using a weighted compact nonlinear scheme

    International Nuclear Information System (INIS)

    Zuo, Zhifeng; Maekawa, Hiroshi

    2014-01-01

    The interaction between a moderate-strength shock wave and a near-wall vortex is studied numerically by solving the two-dimensional, unsteady compressible Navier–Stokes equations using a weighted compact nonlinear scheme with a simple low-dissipation advection upstream splitting method for flux splitting. Our main purpose is to clarify the development of the flow field and the generation of sound waves resulting from the interaction. The effects of the vortex–wall distance on the sound generation associated with variations in the flow structures are also examined. The computational results show that three sound sources are involved in this problem: (i) a quadrupolar sound source due to the shock–vortex interaction; (ii) a dipolar sound source due to the vortex–wall interaction; and (iii) a dipolar sound source due to unsteady wall shear stress. The sound field is the combination of the sound waves produced by all three sound sources. In addition to the interaction of the incident shock with the vortex, a secondary shock–vortex interaction is caused by the reflection of the reflected shock (MR2) from the wall. The flow field is dominated by the primary and secondary shock–vortex interactions. The generation mechanism of the third sound, which is newly discovered, due to the MR2–vortex interaction is presented. The pressure variations generated by (ii) become significant with decreasing vortex–wall distance. The sound waves caused by (iii) are extremely weak compared with those caused by (i) and (ii) and are negligible in the computed sound field. (paper)

  7. Material Evidence for Ocean Impact from Shock-Metamorphic Experiments

    Science.gov (United States)

    Miura, Y.; Takayama, K.; Iancu, O. G.

    1993-07-01

    Continental impact reveals an excavated crater that has few fresh fine ejecta showing major high shock metamorphism due to weathering [1]. A giant ocean impact rarely remains as an excavated crater mainly due to crushing by dynamic plate-tectonic movements on the crust [2]. However, all impact materials, including fine-grained ejecta, can be obtained with artificial impact experiments [3]. The purpose of this study is to discuss material evidence for ocean impact based on shock-metamorphic experiments. Artificial impact experiments indicate that fine shocked quartz (SQ) aggregates can be formed on several target rocks (Table 1) [1]. It is found in Table 1 that (1) the largest-density deviation of SQ grain is found not at the wall-rock or the impact crater but at fine-grained ejecta, and (2) silica-poor rocks of basalt, gabbro, and anorthosite can also make fine SQ aggregates by impact. Table 1, which appears here in the hard copy, shows formations of fine shocked quartz aggregates from ocean-floor rocks of basalt, gabbroic anorthosite, and granite [3]. An asteroid (about 10 km across) hits the Earth ~65 m.y. ago [4] to result in global catastrophe by titanic explosion and climate change. But shocked quartz grains found in the K/T boundary layer were considered to come from crystalline continental rocks [5]. The present result as listed in Table 1 indicates that fine SQ aggregates can also be formed at sea-floor basaltic and gabbroic rocks [3]. The present result of formation of the SQ grains from sea- floor target rocks is nearly consistent with the finding of a sea-impact crater at the K/T boundary near the Caribbean [6]. Impact-induced volcanism at the K/T boundary can explained by the penetration from thin ocean crust to upper mantle reservoirs, if giant impact of a 10-km- diameter asteroid hit the ocean [2,7]. The present result can explain "phreatomagmatic (magmatic vapor) explosion," which is created by abrupt boiling between high-temperature magma and cold

  8. Shock initiation experiments on ratchet grown PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsen, Richard L [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory; Olinger, Barton W [Los Alamos National Laboratory; Deluca, Racci [Los Alamos National Laboratory; Bartram, Brian D [Los Alamos National Laboratory; Pierce, Timothy H [Los Alamos National Laboratory; Sanchez, Nathaniel J [Los Alamos National Laboratory

    2010-01-01

    This study compares the shock initiation behavior of PBX 9502 pressed to less than nominal density (nominal density is 1.890 {+-} 0.005 g/cm{sup 3}) with PBX 9502 pressed to nominal density and then ''ratchet grown'' to low density. PBX 9502 is an insensitive plastic bonded explosive consisting of 95 weight % dry-aminated tri-amino-tri-nitro-benzene (TATB) and 5 weight % Kel-F 800 plastic binder. ''Ratchet growth'' - an irreversible increase in specific volume - occurs when an explosive based on TATB is temperature cycled. The design of our study is as follows: PBX 9502, all from the same lot, received the following four treatments. Samples in the first group were pressed to less than nominal density. These were not ratchet grown and used as a baseline. Samples in the second group were pressed to nominal density and then ratchet grown by temperature cycling 30 times between -54 C and +80 C. Samples in the final group were pressed to nominal density and cut into 100 mm by 25.4 mm diameter cylinders. During thermal cycling the cylinders were axially constrained by a 100 psi load. Samples for shock initiation experiments were cut perpendicular (disks) and parallel (slabs) to the axial load. The four sample groups can be summarized with the terms pressed low, ratchet grown/no load, axial load/disks, and axial load/slabs. All samples were shock initiated with nearly identical inputs in plate impact experiments carried out on a gas gun. Wave profiles were measured after propagation through 3, 4, 5, and 6 mm of explosive. Side by side comparison of wave profiles from different samples is used as a measure of relative sensitivity. All reduced density samples were more shock sensitive than nominal density PBX 9502. Differences in shock sensitivity between ratchet grown and pressed to low density PBX 9502 were small, but the low density pressings are slightly more sensitive than the ratchet grown samples.

  9. A Fiber Interferometer for the Magnetized Shock Experiment

    International Nuclear Information System (INIS)

    Yoo, Christian

    2012-01-01

    The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory requires remote diagnostics of plasma density. Laser interferometry can be used to determine the line-integrated density of the plasma. A multi-chord heterodyne fiber optic Mach-Zehnder interferometer is being assembled and integrated into the experiment. The advantage of the fiber coupling is that many different view chords can be easily obtained by simply moving transmit and receive fiber couplers. Several such fiber sets will be implemented to provide a time history of line-averaged density for several chords at once. The multiple chord data can then be Abel inverted to provide radially resolved spatial profiles of density. We describe the design and execution of this multiple fiber interferometer.

  10. Shock compression of monocrystalline copper: Experiments, characterization, and analysis

    International Nuclear Information System (INIS)

    Cao Buyang; Lassila, David H.; Huang Chongxiang; Xu Yongbo; Meyers, Marc Andre

    2010-01-01

    Monocrystalline copper samples with [0 0 1] and [2 2 1] orientations were subjected to shock/recovery experiments at 30 and 57 GPa and 90 K. The slip system activity and the microstructural evolution were investigated. Different defect structures, including dislocations, stacking faults, twins, microbands, and recrystallized grains were observed in the specimens. The residual microstructures were dependent on crystalline orientation and pressure. The differences with crystalline orientations are most likely due to different resolved shear stresses on specific crystalline planes. The geometric relationships between the shock propagation direction and crystalline orientation are presented under uniaxial strain. It is shown that the [2 2 1] orientation, by virtue of having fewer highly activated slip systems, exhibits greater concentration of deformation with more intense shear on the primary system. This, in turn leads to greater local temperature rise and full recrystallization, in spite of the thermodynamic residual temperature of ∼500 K and rapid cooling (within 20 s) to ambient temperature. The profuse observation of microbands is interpreted in terms of the mechanism proposed by Huang and Gray [J.C. Huang, G.T. Gray III, Acta Metallurgica 37 (1989) 3335-3347].

  11. Relative Shock Effects in Mixed Powders of Calcite, Gypsum, and Quartz: A Calibration Scheme from Shock Experiments

    Science.gov (United States)

    Bell, Mary S.

    2009-01-01

    The shock behavior of calcite and gypsum is important in understanding the Cretaceous/Tertiary event and other terrestrial impacts that contain evaporite sediments in their targets. Most interest focuses on issues of devolatilization to quantify the production of CO2 or SO2 to better understand their role in generating a temporary atmosphere and its effects on climate and biota [e.g., papers in 1,2,3,4]. Devolatilization of carbonate is also important because the dispersion and fragmentation of ejecta is strongly controlled by the expansion of large volumes of gas during the impact process as well [5,6]. Shock recovery experiments for calcite yield seemingly conflicting results: early experimental devolatilization studies [7,8,9] suggested that calcite was substantially outgassed at 30 GPa (> 50%). However, the recent petrographic work of [10,11,12] presented evidence that essentially intact calcite is recovered from 60 GPa experiments. [13] reported results of shock experiments on anhydrite, gypsum, and mixtures of those phases with silica. Their observations indicate little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another (preliminary) report of shock experiments on calcite, anhydrite, and gypsum, [14] observe calcite recrystallization when shock loaded at 61 GPa, only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa. [15] shock loaded anhydrite and quartz to a peak pressure of 60 GPa. All of the quartz grains were trans-formed to glass and the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggest that recrystallization of anhydrite grains is the result of a solid state transformation. [16] reanalyzed the calcite and anhydrite shock

  12. Results from the RACE [Ring ACceleration Experiment] Compact Torus Acceleration Experiment

    International Nuclear Information System (INIS)

    Hammer, J.H.; Hartman, C.W.; Eddleman, J.L.; Kusse, B.

    1987-06-01

    RACE (Ring ACceleration Experiment) is a proof-of-principle experiment aimed at demonstrating acceleration of magnetically confined compact torus plasma rings to directed kinetic energies well in excess of their magnetic and thermal energies. In the course of the first year of operation the following have been observed: successful formation of rings in the RACE geometry; acceleration of rings with large forces, F/sub accelerate/ ∼F/sub equilibrium/ without apparent degradation of the ring structure; peak velocities of ≅2.5 x 10 8 cm/sec; acceleration efficiency of >30% at speeds of 1.5 x 10 8 cm/sec inferred from trajectory and capacitor bank data; kinetic to magnetic energy ratios ∼10 were observed. Experiments in the near future will be aimed at confirmation of the mass/energy measurements by calorimetry and direct density measurements

  13. Melting Behaviour of Mo by Shock Wave Experiment

    International Nuclear Information System (INIS)

    Xiu-Lu, Zhang; Ling-Cang, Cai; Jun, Chen; Ji-An, Xu; Fu-Qian, Jing

    2008-01-01

    In order to clarify the apparent discrepancy in determinations of melting temperature T m of Mo between diamond-anvil cell (DAC) measurements from 0 to about 100 GPa and shock wave (SW) measurement at only one pressure of about 390 GPa by comparison with visual extrapolation, we perform SW experiments to replenish more T m data on purpose to make this comparison more directly and rationally as well. The techniques adopted consist of Hügoniot sound velocity measurement for porous Mo and shock-induced release T m measurements for both solid and porous Mo. Totally five SW T m data, which extends the measured pressure range from previous about 390 GPa down to about 136 GPa that is close to the highest pressure (about 100 GPa) attained by previous DAC experiments, are therefore obtained. These measured Tm data, other than the extrapolated as mentioned above, exhibit a manner of continuous variation with pressure and can be fitted well with Lindemann melting description. More significantly, the measured T m data at lowest pressure are still much higher than that of the DACs and the overall trend of these T m data is against to the two-segment melting curve model, with a sudden change in dT m /d P at about 210 GPa, previously proposed by Errandonea [Physica B 357 (2005) 356]. Though the problem of large discrepancy in T m data measured between DAC and SW has not been completely explained, our knowledge on this matter achieves indubitable progress since it is of value to programme the next clarification. Some suggestions for further clarifying the issue of large discrepancy between DAC and SW measurements are also proposed. (condensed matter: structure, mechanical and thermal properties)

  14. Component manufacturing development for the National Compact Stellarator Experiment (NCSX)

    International Nuclear Information System (INIS)

    Heitzenroeder, P.J.; Brown, T.G.; Chrzanowski, J.H.; Neilson, G.H.; Reiersen, W.T.; Sutton, L.L.; Viola, M.E.; Cole, M.J.; Goranson, P.L.; Nelson, B.E.; Williamson, D.E.

    2005-01-01

    NCSX is the first of a new class of stellarators called compact stellarators which hold the promise of retaining the steady state feature of the stellarator but at a much lower aspect ratio and using a quasi-axisymmetric magnetic field to obtain tokamak-like performance. Although much of NCSX is conventional in design and construction, the vacuum vessel and modular coils provide significant engineering challenges due to their complex shapes, need for high dimensional accuracy, and the need for high current density in the modular coils due space constraints. Consequently, a three-phase development program has been undertaken. In the first phase, laboratory / industrial studies were performed during the development of the conceptual design to permit advances in manufacturing technology to be incorporated into NCSX's plans. In the second phase, full-scale prototype modular coil winding forms, compacted cable conductors, and 20-degree sectors of the vacuum vessel were fabricated in industry. In parallel, the NCSX project team undertook R and D studies that focused on the windings. The third (production) phase began in September 2004. First plasma is scheduled for January 2008. (author)

  15. Some techniques and results from high-pressure shock-wave experiments utilizing the radiation from shocked transparent materials

    International Nuclear Information System (INIS)

    McQueen, R.G.; Fritz, J.N.

    1981-01-01

    It has been known for many years that some transparent materials emit radiation when shocked to high pressures. This property was used to determine the temperature of shocked fused and crystal quartz, which in turn allowed the thermal expansion of SiO 2 at high pressure and also the specific heat to be calculated. Once the radiative energy as a function of pressure is known for one material it is shown how this can be used to determine the temperature of other transparent materials. By the nature of the experiments very accurate shock velocities can be measured and hence high quality equation of state data obtained. Some techniques and results are presented on measuring sound velocities from symmetrical impact of nontransparent materials using radiation emitting transparent analyzers, and on nonsymmetrical impact experiments on transparent materials. Because of special requirements in the later experiments, techniques were developed that lead to very high-precision shock-wave data. Preliminary results, using these techniques are presented for making estimates of the melting region and the yield strength of some metals under strong shock conditions

  16. The Septic Shock 3.0 Definition and Trials: A Vasopressin and Septic Shock Trial Experience.

    Science.gov (United States)

    Russell, James A; Lee, Terry; Singer, Joel; Boyd, John H; Walley, Keith R

    2017-06-01

    The Septic Shock 3.0 definition could alter treatment comparisons in randomized controlled trials in septic shock. Our first hypothesis was that the vasopressin versus norepinephrine comparison and 28-day mortality of patients with Septic Shock 3.0 definition (lactate > 2 mmol/L) differ from vasopressin versus norepinephrine and mortality in Vasopressin and Septic Shock Trial. Our second hypothesis was that there are differences in plasma cytokine levels in Vasopressin and Septic Shock Trial for lactate less than or equal to 2 versus greater than 2 mmol/L. Retrospective analysis of randomized controlled trial. Multicenter ICUs. We compared vasopressin-to-norepinephrine group 28- and 90-day mortality in Vasopressin and Septic Shock Trial in lactate subgroups. We measured 39 cytokines to compare patients with lactate less than or equal to 2 versus greater than 2 mmol/L. Patients with septic shock with lactate greater than 2 mmol/L or less than or equal to 2 mmol/L, randomized to vasopressin or norepinephrine. Concealed vasopressin (0.03 U/min.) or norepinephrine infusions. The Septic Shock 3.0 definition would have decreased sample size by about half. The 28- and 90-day mortality rates were 10-12 % higher than the original Vasopressin and Septic Shock Trial mortality. There was a significantly (p = 0.028) lower mortality with vasopressin versus norepinephrine in lactate less than or equal to 2 mmol/L but no difference between treatment groups in lactate greater than 2 mmol/L. Nearly all cytokine levels were significantly higher in patients with lactate greater than 2 versus less than or equal to 2 mmol/L. The Septic Shock 3.0 definition decreased sample size by half and increased 28-day mortality rates by about 10%. Vasopressin lowered mortality versus norepinephrine if lactate was less than or equal to 2 mmol/L. Patients had higher plasma cytokines in lactate greater than 2 versus less than or equal to 2 mmol/L, a brisker cytokine response to infection. The Septic

  17. One surgeon's Army experience with "wound shock" from Pearl Harbor to the present.

    Science.gov (United States)

    Hardaway, Robert M

    2009-09-01

    The Army has had extensive experience in the study and treatment of shock, beginning with the American Civil War and continuing to the present. This is the story of one Army surgeon's experience, both in research and treatment of shock, from Pearl Harbor to the present.

  18. Dynamic shock compaction of a ZrO2-RuO2 electronic nanocomposite: toward functionally graded materials

    NARCIS (Netherlands)

    van Zyl, W.E.; Carton, Erik P.; Raming, T.P.; ten Elshof, Johan E.; Verweij, H.

    2005-01-01

    An electronic ZrO2-RuO2 nanocomposite was fabricated by dynamic compaction (DC) at 1.5 GPa resulting in a maximum relative density of 88% in the material. The DC process formed pristine elongated conical-shaped compacts 3 cm in length. The compacts retained their original nanometer-sized grains (~20

  19. Shock-ignition relevant experiments with planar targets on OMEGA

    Energy Technology Data Exchange (ETDEWEB)

    Hohenberger, M.; Hu, S. X.; Anderson, K. S.; Boehly, T. R.; Sangster, T. C.; Seka, W.; Stoeckl, C.; Yaakobi, B. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Casner, A. [CEA, DAM, DIF, Arpajon (France); Fratanduono, D. E. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); Ribeyre, X.; Schurtz, G. [Centre Lasers Intenses et Applications, CELIA, Université Bordeaux 1-CEA-CNRS, Talence (France)

    2014-02-15

    We report on laser-driven, strong-shock generation and hot-electron production in planar targets in the presence of a pre-plasma at shock-ignition (SI) relevant laser and pre-plasma conditions. 2-D simulations reproduce the shock dynamics well, indicating ablator shocks of up to 75 Mbar have been generated. We observe hot-electron temperatures of ∼70 keV at intensities of 1.4 × 10{sup 15} W/cm{sup 2} with multiple overlapping beams driving the two-plasmon decay instability. When extrapolated to SI-relevant intensities of ∼10{sup 16} W/cm{sup 2}, the hot electron temperature will likely exceed 100 keV, suggesting that tightly focused beams without overlap are better suited for launching the ignitor shock.

  20. Microgravity Experiment: The Fate of Confined Shock Waves

    Science.gov (United States)

    Kobel, P.; Obreschkow, D.; Dorsaz, N.; de Bosset, A.; Farhat, M.

    2007-11-01

    Shockwave induced cavitation is a form of hydrodynamic cavitation generated by the interaction of shock waves with vapor nuclei and microscopic impurities. Both the shock waves and the induced cavitation are known as sources of erosion damage in hydraulic industrial systems and hence represent an important research topic in fluid dynamics. Here we present the first investigation of shock wave induced cavitation inside closed and isolated liquid volumes, which confine the shock wave by reflections and thereby promise a particularly strong coupling with cavitation. A microgravity platform (ESA, 42^nd parabolic flight campaign) was used to produce stable water drops with centimetric diameters. Inside these drops, a fast electrical discharge was generated to release a strong shock wave. This setting results in an amplified form of shockwave induced cavitation, visible in high-speed images as a transient haze of sub-millimetric bubbles synchronized with the shockwave radiation. A comparison between high-speed visualizations and 3D simulations of a shock front inside a liquid sphere reveals that focus zones within the drop lead to a significantly increased density of induced cavitation. Considering shock wave crossing and focusing may hence prove crucially useful to understand the important process of cavitation erosion.

  1. 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.

  2. 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.

  3. Introduction to the special issue on experiences with the impact and prevention of subsoil compaction in the European Union

    NARCIS (Netherlands)

    Akker, van den J.J.H.; Arvidsson, J.; Horn, R.

    2003-01-01

    The papers in this special issue present results of the European Union (EU) concerted action ¿Experiences with the impact of subsoil compaction on soil crop growth and environment and ways to prevent subsoil compaction¿. The results and conclusions of earlier research on subsoil compaction are

  4. Hot Cathode Biasing Experiment in Compact Helical System

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, H.; Utoh, H.; Kitajima, S.; Isobe, M.; Suzuki, C.; Takeuchi, M.; Ikeda, R.; Tanaka, Y.; Yokoyama, M.; Toi, K.; Okamura, S.; Sasao, M.

    2005-07-01

    One of the H mode characteristics is a sudden formation of a radial electric field at LH transition. To date, H mode was widely observed in various tokamaks [1-3] and stellarator devices [4, 5], and the importance of the radial electric field has been shown in both experiments and in theory. However, it is difficult to investigate the behaviour of a radial electric field in detail at LH transition induced by NBI heating because the radial electric field is self-organised and changes suddenly. Electrode bias experiments are methods for active control of the radial electric field. The electrode bias experiment has the advantage of the ability to control the radial electric field externally by controlling the electrode voltage and/or the electrode current and to estimate the driving force from the electrode current. The neoclassical theory indicates the criterion of LH transition from the viewpoint of the ion viscosity. In this theory, the ion viscosity has local maxima against the rotation velocity [6-8]. When the driving force in the poloidal direction exceeds a critical value, the poloidal rotation velocity increases rapidly and the plasma undergoes a transition to the H mode. This means that the LH transition mechanism is a bifurcation phenomenon due to the existence of local maxima in the ion viscosity. Here, we carried out the electrode biasing experiment in TU-Heliac and CHS to investigate the effect of ripple structure on ion viscosity and to clarify the role of ion viscosity in triggering the transition from the degraded state to enhanced confinement. (Author)

  5. Compact diffraction grating laser wavemeter for cold atom experiments

    Science.gov (United States)

    Wei, Chun-hua; Yan, Shu-hua; Zhang, Tian

    2017-09-01

    We present an innovative and practical scheme of building a miniaturized wavemeter, with the advantages of low cost, high reliability and simple structure. Through a calibration test by a 780 nm external cavity diode laser (ECDL), the results show that our system gets a wavelength resolution of better than 1 pm, measurement accuracy of better than 2 pm (corresponding to a frequency of 1 GHz), and a measurement range of 8.5 nm. Finally, the multi-mode comparison test between our system and a commercial spectrum analyzer further indicates the high-precision, miniaturization and low cost of the proposed system, which shows that it is particularly suitable for ECDL and atom cooling and trapping experiments. The system design, experimental results and conclusions are of definite significance as a fine reference for other ranges of wavelength.

  6. Supersymmetry Searches at the Compact Muon Solenoid (CMS Experiment, 2011

    Directory of Open Access Journals (Sweden)

    Koay S. A.

    2012-06-01

    Full Text Available The discovery/exclusion of Supersymmetric models for fundamental interactions of particles is one of the milestones targeted by the Large Hadron Collider (LHC, and in particular comprises of a large part of the physics program of the CMS experiment. Since the initial measurements using the 36 pb−1 of integrated luminosity delivered by the LHC in 2010, presently available results utilize about one fifth of the data delivered in 2011, i.e. in the ballpark of 1 fb−1, significantly extending the world limits placed on gluino and squark production signals. An overview of these analyses is presented, highlighting four that had been newly made public as of the date of this conference. The evidence for Supersymmetry (SUSY is still elusive, and a discussion follows as to where current searches have not yet probed, also pointing out where they might have difficulty ever probing without dedicated arrangements.

  7. Analysing the control software of the Compact Muon Solenoid Experiment at the Large Hadron Collider

    NARCIS (Netherlands)

    Hwong, Y.L.; Kusters, V.J.J.; Willemse, T.A.C.; Arbab, F.; Sirjani, M.

    2012-01-01

    The control software of the CERN Compact Muon Solenoid experiment contains over 30,000 finite state machines. These state machines are organised hierarchically: commands are sent down the hierarchy and state changes are sent upwards. The sheer size of the system makes it virtually impossible to

  8. Alfven Continuum and Alfven Eigenmodes in the National Compact Stellarator Experiment

    International Nuclear Information System (INIS)

    Fesenyuk, O.P.; Kolesnichenko, Ya.I.; Lutsenko, V.V.; White, R.B.; Yakovenko, Yu.V.

    2004-01-01

    The Alfven continuum (AC) in the National Compact Stellarator Experiment (NCSX) is investigated with the AC code COBRA. The resonant interaction of Alfven eigenmodes and the fast ions produced by neutral beam injection is analyzed. Alfven eigenmodes residing in one of the widest gaps of the NCSX AC, the ellipticity-induced gap, are studied with the code BOA-E

  9. Experiments on second-sound shock waves in superfluid helium

    International Nuclear Information System (INIS)

    Cummings, J.C.; Schmidt, D.W.; Wagner, W.J.

    1978-01-01

    The waveform and velocity of second-sound waves in superfluid helium have been studied experimentally using superconducting, thin-film probes. The second-sound waves were generated with electrical pulses through a resistive film. Variations in pulse power, pulse duration, and bath temperature were examined. As predicted theoretically, the formation of a shock was observed at the leading or trailing edge of the waves depending on bath temperature. Breakdown of the theoretical model was observed for large pulse powers. Accurate data for the acoustic second-sound speed were derived from the measurements of shock-wave velocities and are compared with previous results

  10. Laser driven shock wave experiments for equation of state studies at megabar pressures

    CERN Document Server

    Pant, H C; Senecha, V K; Bandyopadhyay, S; Rai, V N; Khare, P; Bhat, R K; Gupta, N K; Godwal, B K

    2002-01-01

    We present the results from laser driven shock wave experiments for equation of state (EOS) studies of gold metal. An Nd:YAG laser chain (2 J, 1.06 mu m wavelength, 200 ps pulse FWHM) is used to generate shocks in planar Al foils and Al + Au layered targets. The EOS of gold in the pressure range of 9-13 Mbar is obtained using the impedance matching technique. The numerical simulations performed using the one-dimensional radiation hydrodynamic code support the experimental results. The present experimental data show remarkable agreement with the existing standard EOS models and with other experimental data obtained independently using laser driven shock wave experiments.

  11. The Capacity for Compaction Weakening in Fault Gouge in Nature and Experiment

    Science.gov (United States)

    Faulkner, D.; Boulton, C. J.; Sanchez Roa, C.; Den Hartog, S. A. M.; Bedford, J. D.

    2017-12-01

    As faults form in low permeability rocks, the compaction of fault gouge can lead to significant pore-fluid pressure increases. The pore pressure increase results from the collapse of the porosity through shear-enhanced compaction and the low hydraulic diffusivity of the gouge that inhibits fluid flow. In experiments, the frictional properties of clay-bearing fault gouges are significantly affected by the development of locally high pore-fluid pressures when compaction rates are high due to fast displacement rates or slip in underconsolidated materials. We show how the coefficient of friction of fault gouges sheared at different slip velocities can be explained with a numerical model that is constrained by laboratory measurements of contemporaneous changes in permeability and porosity. In nature, for compaction weakening to play an important role in earthquake nucleation (and rupture propagation), a mechanism is required to reset the porosity, i.e., maintain underconsolidated gouge along the fault plane. We use the observations of structures within the principal slip zone of the Alpine Fault in New Zealand to suggest that cyclic fluidization of the gouge occurs during coseismic slip, thereby resetting the gouge porosity prior to the next seismic event. Results from confined laboratory rotary shear measurements at elevated slip rates appear to support the hypothesis that fluidization leads to underconsolidation and, thus, to potential weakening by shear-enhanced compaction-induced pore-fluid pressurization.

  12. Neutral Beam Injection Requirements and Design Issues for the National Compact Stellarator Experiment; TOPICAL

    International Nuclear Information System (INIS)

    H.W. Kugel; H. Neilson; W. Reiersen; M. Zarnstorff

    2002-01-01

    The National Compact Stellarator Experiment (NCSX) will require 6 MW of 50 keV neutral beam injection (NBI) with initial pulse lengths of 500 msec and upgradeable to pulse lengths of 1.5 sec. This paper discusses the NCSX NBI requirements and design issues, and shows how these are provided by the candidate PBX-M[Princeton Beta Experiment-Modification] NBI system

  13. Neutral Beam Injection Requirements and Design Issues for the National Compact Stellarator Experiment

    International Nuclear Information System (INIS)

    Kugel, H.W.; Neilson, H.; Reiersen, W.; Zarnstorff, M.

    2002-01-01

    The National Compact Stellarator Experiment (NCSX) will require 6 MW of 50 keV neutral beam injection (NBI) with initial pulse lengths of 500 msec and upgradeable to pulse lengths of 1.5 sec. This paper discusses the NCSX NBI requirements and design issues, and shows how these are provided by the candidate PBX-M [Princeton Beta Experiment-Modification] NBI system

  14. Electron Microscopic Examination of Irradiated TRISO Coated Particles of Compact 6-3-2 of AGR-1 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Van Rooyen, Isabella Johanna [Idaho National Lab. (INL), Idaho Falls, ID (United States); Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States); Riesterer, Jessica Lori [Idaho National Lab. (INL), Idaho Falls, ID (United States); Miller, Brandon Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Janney, Dawn Elizabeth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ploger, Scott Arden [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2012-12-01

    The electron microscopic examination of selected irradiated TRISO coated particles of the AGR-1 experiment of fuel compact 6-3-2 are presented in this report. Compact 6-3-2 refers to the compact in Capsule 6 at level 3 of Stack 2. The fuel used in capsule 6 compacts, are called the “baseline” fuel as it is fabricated with refined coating process conditions used to fabricate historic German fuel, because of its excellent irradiation performance with UO2 kernels. The AGR-1 fuel is however made of low-enriched uranium oxycarbide (UCO). Kernel diameters are approximately 350 µm with a U-235 enrichment of approximately 19.7%. Compact 6-3-2 has been irradiated to 11.3% FIMA compact average burn-up with a time average, volume average temperature of 1070.2°C and with a compact average fast fluence of 2.38E21 n/cm

  15. Compact streak camera for the shock study of solids by using the high-pressure gas gun

    Science.gov (United States)

    Nagayama, Kunihito; Mori, Yasuhito

    1993-01-01

    For the precise observation of high-speed impact phenomena, a compact high-speed streak camera recording system has been developed. The system consists of a high-pressure gas gun, a streak camera, and a long-pulse dye laser. The gas gun installed in our laboratory has a muzzle of 40 mm in diameter, and a launch tube of 2 m long. Projectile velocity is measured by the laser beam cut method. The gun is capable of accelerating a 27 g projectile up to 500 m/s, if helium gas is used as a driver. The system has been designed on the principal idea that the precise optical measurement methods developed in other areas of research can be applied to the gun study. The streak camera is 300 mm in diameter, with a rectangular rotating mirror which is driven by an air turbine spindle. The attainable streak velocity is 3 mm/microsecond(s) . The size of the camera is rather small aiming at the portability and economy. Therefore, the streak velocity is relatively slower than the fast cameras, but it is possible to use low-sensitivity but high-resolution film as a recording medium. We have also constructed a pulsed dye laser of 25 - 30 microsecond(s) in duration. The laser can be used as a light source of observation. The advantage for the use of the laser will be multi-fold, i.e., good directivity, almost single frequency, and so on. The feasibility of the system has been demonstrated by performing several experiments.

  16. [Our experience in Fournier's gangrene with severe septic shock].

    Science.gov (United States)

    Lukász, Péter; Ecsedy, Gábor; Lovay, Zoltán; Nagy, István; Kári, Dániel; Vörös, Attila; Ender, Ferenc

    2014-06-01

    Fournier's gangrene is a rare, rapidly progressing necrotizing fasciitis, which involves the genital area and perineum, progresses towards the thighs and abdominal wall through fascial plains. In our surgical department we treated seven patients with Fournier's gangrene between 2007 and 2011. Early diagnosis, immediate radical surgical debridement, necrosectomy, appropriate antibiotics and intensive care are all required and necessary for the successful treatment. Despite appropriate therapy, two patients were lost in septic shock.

  17. Astrophysical radiative shocks: From modeling to laboratory experiments

    Czech Academy of Sciences Publication Activity Database

    Gonzales, N.; Stehlé, C.; Audit, E.; Busquet, M.; Rus, Bedřich; Thais, F.; Acef, O.; Barroso, P.; Bar-Shalom, A.; Bauduin, D.; Kozlová, Michaela; Lery, T.; Madouri, A.; Mocek, Tomáš; Polan, Jiří

    2006-01-01

    Roč. 24, - (2006), s. 535-540 ISSN 0263-0346 EU Projects: European Commission(XE) 506350 - LASERLAB-EUROPE; European Commission(XE) 5592 - JETSET Grant - others:CNRS(FR) PNPS Institutional research plan: CEZ:AV0Z10100523 Keywords : laboratory astrophysics * laser plasmas * radiative shock waves * radiative transfer Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.958, year: 2006

  18. Improved Reactive Flow Modeling of the LX-17 Double Shock Experiments

    Science.gov (United States)

    Rehagen, Thomas J.; Vitello, Peter

    2017-06-01

    Over driven double shock experiments provide a measurement of the properties of the reaction product states of the insensitive high explosive LX-17 (92.5% TATB and 7.5% Kel-F by weight). These experiments used two flyer materials mounted on the end of a projectile to send an initial shock through the LX-17, followed by a second shock of a higher magnitude into the detonation products. In the experiments, the explosive was initially driven by the flyer plate to pressures above the Chapman-Jouguet state. The particle velocity history was recorded by Photonic Doppler Velocimetry (PDV) probes pointing at an aluminum foil coated LiF window. The PDV data shows a sharp initial shock and decay, followed by a rounded second shock. Here, the experimental results are compared to 2D and 3D Cheetah reactive flow modeling. Our default Cheetah reactive flow model fails to accurately reproduce the decay of the first shock or the curvature or strength of the second shock. A new model is proposed in which the carbon condensate produced in the reaction zone is controlled by a kinetic rate. This allows the carbon condensate to be initially out of chemical equilibrium with the product gas. This new model reproduces the initial detonation peak and decay, and matches the curvature of the second shock, however, it still over-predicts the strength of the second shock. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  19. Numerical simulations of a nonequilibrium argon plasma in a shock-tube experiment

    Science.gov (United States)

    Cambier, Jean-Luc

    1991-01-01

    A code developed for the numerical modeling of nonequilibrium radiative plasmas is applied to the simulation of the propagation of strong ionizing shock waves in argon gas. The simulations attempt to reproduce a series of shock-tube experiments which will be used to validate the numerical models and procedures. The ability to perform unsteady simulations makes it possible to observe some fluctuations in the shock propagation, coupled to the kinetic processes. A coupling mechanism by pressure waves, reminiscent of oscillation mechanisms observed in detonation waves, is described. The effect of upper atomic levels is also briefly discussed.

  20. Hydrodynamic modeling and explosive compaction of ceramics

    International Nuclear Information System (INIS)

    Hoenig, C.; Holt, A.; Finger, M.; Kuhl, W.

    1977-01-01

    High-density ceramics with high-strength microstructure were achieved by explosive compaction. Well-characterized Al 2 O 3 , AlN, and boron powders were explosively compacted in both cylindrical and flat plate geometries. In cylindrical geometries compacted densities between 91 and 98 percent of theoretical were achieved. Microhardness measurements indicated that the strength and integrity of the microstructure were comparable to conventionally fabricated ceramics, even though all samples with densities greater than 90 percent theoretical contained macrocracks. Fractured surfaces evaluated by SEM showed evidence of boundary melting. Equation of state data for porous Al 2 O 3 were used to calculate the irreversible work done on the sample as a function of pressure. This was expressed as a percentage of the total sample which could be melted. Calculations show that very little melting can be expected in samples shocked to less than 3 GPa. Significant melting and grain boundary fusion can be expected in samples shocked to pressures greater than 8 GPa. Hydrodynamic modeling of right cylinder compaction with detonation at one end was attempted by using a two-dimensional computer code. The complications of this analysis led to experiments using plane shock waves. Flat-plate compaction assemblies were designed and analyzed by 2-D hydrodynamic codes. The use of porous shock attenuators was evaluated. Experiments were performed on aluminum oxide powders in plane wave geometry. Microstructure evaluations were made as a function of location in the flat plate samples. 11 figures, 1 table

  1. Are distribution coefficients measured from batch experiments meaningful for quantifying retention in compacted material?

    Energy Technology Data Exchange (ETDEWEB)

    Goutelard, F.; Charles, Y.; Page, J. [CEA/DEN/DPC/SECR/L3MR batiment 450, 91191 Gif sur Yvette (France)

    2005-07-01

    Full text of publication follows: To quantify the ability of a clayey material to act as a barrier for radionuclides migration, reliable data on retention properties must be available. The most common method for determining the distribution coefficient, quantifying the radionuclide adsorption, is the batch technique applied to powdered solid. Are these data meaningful for highly compacted minerals? This question is still under debate in literature [1,2]. The aim of the present study is to compare distribution coefficient (KD) value for Cs and Ni onto compacted and dispersed for both Bentonite MX80 and Callovo-Oxfordian clayey material in a simulated site water. Firstly, classical batch sorption experiments are carried on dispersed materials pre-conditioned with the simulated site water at pH 7.3. Radiotracer {sup 137}Cs and {sup 58}Ni are used to investigate the constant-pH isotherm sorption. The bottleneck for measuring distribution coefficient onto highly compacted material lies in a careful monitoring of chemical conditions because they are driven by diffusion processes. For this study, we have chosen to use in-diffusion experiments [3]. Sample size is optimized to reach for high retention level (300 mL/g) the steady state in a reasonable time (3 to 6 month). In order to describe the response surface of compacted distribution coefficient on bentonite MX80, a 2 variables Doehlert matrix has been chosen. In this experimental design, the two variables are density and dispersed distribution coefficient. Bentonite is pre-conditioning before compaction to a density ranging from 1.2 to 1.85 kg/l. The pellet is confined in a cylindrical stainless steel filter (150 {mu}L) closed to both ends. The cell is placed in a tightly closed bottle containing the working solution. After a re-equilibration period (at least 3 weeks), {sup 133}Cs and {sup 59}Ni stable isotope are introduced for monitoring the KD level (between 150 mL/g to 330 mL/g). Radiotracer {sup 137}Cs and {sup 58

  2. Are distribution coefficients measured from batch experiments meaningful for quantifying retention in compacted material?

    International Nuclear Information System (INIS)

    Goutelard, F.; Charles, Y.; Page, J.

    2005-01-01

    Full text of publication follows: To quantify the ability of a clayey material to act as a barrier for radionuclides migration, reliable data on retention properties must be available. The most common method for determining the distribution coefficient, quantifying the radionuclide adsorption, is the batch technique applied to powdered solid. Are these data meaningful for highly compacted minerals? This question is still under debate in literature [1,2]. The aim of the present study is to compare distribution coefficient (KD) value for Cs and Ni onto compacted and dispersed for both Bentonite MX80 and Callovo-Oxfordian clayey material in a simulated site water. Firstly, classical batch sorption experiments are carried on dispersed materials pre-conditioned with the simulated site water at pH 7.3. Radiotracer 137 Cs and 58 Ni are used to investigate the constant-pH isotherm sorption. The bottleneck for measuring distribution coefficient onto highly compacted material lies in a careful monitoring of chemical conditions because they are driven by diffusion processes. For this study, we have chosen to use in-diffusion experiments [3]. Sample size is optimized to reach for high retention level (300 mL/g) the steady state in a reasonable time (3 to 6 month). In order to describe the response surface of compacted distribution coefficient on bentonite MX80, a 2 variables Doehlert matrix has been chosen. In this experimental design, the two variables are density and dispersed distribution coefficient. Bentonite is pre-conditioning before compaction to a density ranging from 1.2 to 1.85 kg/l. The pellet is confined in a cylindrical stainless steel filter (150 μL) closed to both ends. The cell is placed in a tightly closed bottle containing the working solution. After a re-equilibration period (at least 3 weeks), 133 Cs and 59 Ni stable isotope are introduced for monitoring the KD level (between 150 mL/g to 330 mL/g). Radiotracer 137 Cs and 58 Ni are used to quantify the

  3. Thermal-shock experiments with flawed clad cylinders

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Bryson, J.W.; Alexander, D.J.

    1989-01-01

    The life expectancy of LWR pressure vessels is influenced by a reduction in fracture toughness that is the result of radiation damage. As the fracture toughness decreases, the probability of propagation of preexisting flaws (sharp, crack-like defects) in the wall of the vessel increases. The probability of propagation is also influenced by the type of loading condition and the type of flaws that might exist. A loading condition of particular concern is referred to as pressurized thermal shock (PTS), and a flaw of particular concern for PTS loading conditions is a shallow surface flaw. A sudden cooling (thermal shock) of the inner surface of the vessel results in relatively high tensile stresses and relatively low fracture toughness at the inner surface. In addition, the attenuation of the fast-neutron fluence also results in relatively low fracture toughness at the inner surface. Under some circumstances, this combination of high stress and low toughness at the inner surface makes it possible for very shallow surface flaws to propagate. The PTS issue has been under investigation for quite some time, but thus far possible beneficial effects, other than thermal resistance, of the cladding on the inner surface of the vessel have not been included in the analysis of flaw behavior. This document discusses this effect of cladding on surface flaws and crack propagation

  4. BOW SHOCK FRAGMENTATION DRIVEN BY A THERMAL INSTABILITY IN LABORATORY ASTROPHYSICS EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki-Vidal, F.; Lebedev, S. V.; Pickworth, L. A.; Swadling, G. F.; Skidmore, J.; Hall, G. N.; Bennett, M.; Bland, S. N.; Burdiak, G.; De Grouchy, P.; Music, J.; Suttle, L. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Ciardi, A. [Sorbonne Universités, UPMC Univ. Paris 6, UMR 8112, LERMA, F-75005, Paris (France); Rodriguez, R.; Gil, J. M.; Espinosa, G. [Departamento de Fisica de la Universidad de Las Palmas de Gran Canaria, E-35017 Las Palmas de Gran Canaria (Spain); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Hansen, E.; Frank, A., E-mail: f.suzuki@imperial.ac.uk [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

    2015-12-20

    The role of radiative cooling during the evolution of a bow shock was studied in laboratory-astrophysics experiments that are scalable to bow shocks present in jets from young stellar objects. The laboratory bow shock is formed during the collision of two counterstreaming, supersonic plasma jets produced by an opposing pair of radial foil Z-pinches driven by the current pulse from the MAGPIE pulsed-power generator. The jets have different flow velocities in the laboratory frame, and the experiments are driven over many times the characteristic cooling timescale. The initially smooth bow shock rapidly develops small-scale nonuniformities over temporal and spatial scales that are consistent with a thermal instability triggered by strong radiative cooling in the shock. The growth of these perturbations eventually results in a global fragmentation of the bow shock front. The formation of a thermal instability is supported by analysis of the plasma cooling function calculated for the experimental conditions with the radiative packages ABAKO/RAPCAL.

  5. Crack propagation behavior of TiN coatings by laser thermal shock experiments

    International Nuclear Information System (INIS)

    Choi, Youngkue; Jeon, Seol; Jeon, Min-seok; Shin, Hyun-Gyoo; Chun, Ho Hwan; Lee, Youn-seoung; Lee, Heesoo

    2012-01-01

    Highlights: ► The crack propagation behavior of TiN coating after laser thermal shock experiment was observed by using FIB and TEM. ► Intercolumnar cracks between TiN columnar grains were predominant cracking mode after laser thermal shock. ► Cracks were propagated from the coating surface to the substrate at low laser pulse energy and cracks were originated at coating-substrate interface at high laser pulse energy. ► The cracks from the interface spread out transversely through the weak region of the columnar grains by repetitive laser shock. - Abstract: The crack propagation behavior of TiN coatings, deposited onto 304 stainless steel substrates by arc ion plating technique, related to a laser thermal shock experiment has been investigated using focused ion beam (FIB) and transmission electron microscopy (TEM). The ablated regions of TiN coatings by laser ablation system have been investigated under various conditions of pulse energies and number of laser pulses. The intercolumnar cracks were predominant cracking mode following laser thermal shock tests and the cracks initiated at coating surface and propagated in a direction perpendicular to the substrate under low loads conditions. Over and above those cracks, the cracks originated from coating-substrate interface began to appear with increasing laser pulse energy. The cracks from the interface also spread out transversely through the weak region of the columnar grains by repetitive laser shock.

  6. Spall wave-profile and shock-recovery experiments on depleted uranium

    International Nuclear Information System (INIS)

    Hixson, R.S.; Vorthman, J.E.; Gustavsen, R.L.; Zurek, A.K.; Thissell, W.R.; Tonks, D.L.

    1998-01-01

    Depleted Uranium of two different purity levels has been studied to determine spall strength under shock wave loading. A high purity material with approximately 30 ppm of carbon impurities was shock compressed to two different stress levels, 37 and 53 kbar. The second material studied was uranium with about 300 ppm of carbon impurities. This material was shock loaded to three different final stress level, 37, 53, and 81 kbar. Two experimental techniques were used in this work. First, time-resolved free surface particle velocity measurements were done using a VISAR velocity interferometer. The second experimental technique used was soft recovery of samples after shock loading. These two experimental techniques will be briefly described here and VISAR results will be shown. Results of the spall recovery experiments and subsequent metallurgical analyses are described in another paper in these proceedings. copyright 1998 American Institute of Physics

  7. 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

  8. Broadband Laser Ranging for Position Measurements in Shock Physics Experiments

    Science.gov (United States)

    Rhodes, Michelle; Bennett, Corey; Daykin, Edward; Younk, Patrick; Lalone, Brandon; Kostinski, Natalie

    2017-06-01

    Broadband laser ranging (BLR) is a recently developed measurement system that provides an attractive option for determining the position of shock-driven surfaces. This system uses broadband, picosecond (or femtosecond) laser pulses and a fiber interferometer to measure relative travel time to a target and to a reference mirror. The difference in travel time produces a delay difference between pulse replicas that creates a spectral beat frequency. The spectral beating is recorded in real time using a dispersive Fourier transform and an oscilloscope. BLR systems have been designed that measure position at 12.5-40 MHz with better than 100 micron accuracy over ranges greater than 10 cm. We will give an overview of the basic operating principles of these systems. Prepared by LLNL under Contract DE-AC52-07NA27344, by LANL under Contract DE-AC52-06NA25396, and by NSTec Contract DE-AC52-06NA25946.

  9. Shock compression experiments on Lithium Deuteride (LiD) single crystals

    Science.gov (United States)

    Knudson, M. D.; Desjarlais, M. P.; Lemke, R. W.

    2016-12-01

    Shock compression experiments in the few hundred GPa (multi-Mbar) regime were performed on Lithium Deuteride single crystals. This study utilized the high velocity flyer plate capability of the Sandia Z Machine to perform impact experiments at flyer plate velocities in the range of 17-32 km/s. Measurements included pressure, density, and temperature between ˜190 and 570 GPa along the Principal Hugoniot—the locus of end states achievable through compression by large amplitude shock waves—as well as pressure and density of reshock states up to ˜920 GPa. The experimental measurements are compared with density functional theory calculations, tabular equation of state models, and legacy nuclear driven results that have been reanalyzed using modern equations of state for the shock wave standards used in the experiments.

  10. Experiment Analysis and Modelling of Compaction Behaviour of Ag60Cu30Sn10 Mixed Metal Powders

    Science.gov (United States)

    Zhou, Mengcheng; Huang, Shangyu; Liu, Wei; Lei, Yu; Yan, Shiwei

    2018-03-01

    A novel process method combines powder compaction and sintering was employed to fabricate thin sheets of cadmium-free silver based filler metals, the compaction densification behaviour of Ag60Cu30Sn10 mixed metal powders was investigated experimentally. Based on the equivalent density method, the density-dependent Drucker-Prager Cap (DPC) model was introduced to model the powder compaction behaviour. Various experiment procedures were completed to determine the model parameters. The friction coefficients in lubricated and unlubricated die were experimentally determined. The determined material parameters were validated by experiments and numerical simulation of powder compaction process using a user subroutine (USDFLD) in ABAQUS/Standard. The good agreement between the simulated and experimental results indicates that the determined model parameters are able to describe the compaction behaviour of the multicomponent mixed metal powders, which can be further used for process optimization simulations.

  11. Laser driven shock wave experiments for equation of state studies at megabar pressures

    International Nuclear Information System (INIS)

    Pant, H C; Shukla, M; Senecha, V K; Bandyopadhyay, S; Rai, V N; Khare, P; Bhat, R K; Gupta, N K; Godwal, B K

    2002-01-01

    We present the results from laser driven shock wave experiments for equation of state (EOS) studies of gold metal. An Nd:YAG laser chain (2 J, 1.06 μm wavelength, 200 ps pulse FWHM) is used to generate shocks in planar Al foils and Al + Au layered targets. The EOS of gold in the pressure range of 9-13 Mbar is obtained using the impedance matching technique. The numerical simulations performed using the one-dimensional radiation hydrodynamic code support the experimental results. The present experimental data show remarkable agreement with the existing standard EOS models and with other experimental data obtained independently using laser driven shock wave experiments

  12. Laser-generated shock-wave experiments in metals above 1 TPa

    International Nuclear Information System (INIS)

    Trainor, R.J.; Shaner, J.W.; Auerbach, J.M.; Phillion, D.W.

    1978-01-01

    Some initial experiments are described which form part of a new program aimed at significantly extending the range of high pressures and densities which may be explored in laboratory equation-of-state (EOS) experiments. These experiments will utilize high-energy lasers, such as those employed in the Laser Fusion Program at Lawrence Livermore Laboratory (LLL), to generate intense shock waves in materials of interest

  13. X-ray production experiments on the RACE Compact Torus Accelerator

    International Nuclear Information System (INIS)

    Hammer, J.H.; Eddleman, J.L.; Hartman, C.W.; McLean, H.S.; Molvik, A.W.; Gee, M.

    1989-12-01

    The Purpose of the Compact Torus Accelerator (CTA) program at LLNL is to prove the principle of a unique accelerator concept based on magnetically confined compact torus (CT) plasma rings and to study applications. Successful achievement of these goals could lead to a high power-density driver for many applications including an intense x-ray source for nuclear weapons effects simulation and an inertial fusion driver. Fusion applications and a description of the CTA concept are included in a companion paper at this conference. This paper will describe the initial experiments on soft x-ray production conducted on the plasma Ring ACcelerator Experiment (RACE) and compare the results to modeling studies. The experiments on CT stagnation and soft x-ray production were conducted with unfocused rings as a first of CT dynamics and the physics of x-ray production. The x-ray fluences observed are consistent with expectations based on calculations employing a radiation-hydrodynamics code. We conclude with a diffusion of future x-ray production studies that can be conducted on RACE and a possible multi-megajoule upgrade

  14. Attenuation of surface waves in porous media: Shock wave experiments and modelling

    NARCIS (Netherlands)

    Chao, G.E; Smeulders, D.M.J.; Dongen, van M.E.H.

    2005-01-01

    In this project we conduct experimental and numerical investigations on the attenuation mechanisms of surface waves in poroelastic materials. Viscous dissipation effects are modelled in the framework of Biot's theory. The experiments are performed using a shock tube technique. Quantitative agreement

  15. Shock-to-detonation transition of RDX and NTO based composite high explosives: experiments and modeling

    Science.gov (United States)

    Baudin, Gerard; Roudot, Marie; Genetier, Marc

    2013-06-01

    Composite HMX and NTO based high explosives (HE) are widely used in ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside HE. Comparing to a pressed HE, a composite HE is not porous and the hot-spots are mainly located at the grain - binder interface leading to a different behavior during shock-to-detonation transition. An investigation of how shock-to-detonation transition occurs inside composite HE containing RDX and NTO is proposed in this lecture. Two composite HE have been studied. The first one is HMX - HTPB 82:18. The second one is HMX - NTO - HTPB 12:72:16. These HE have been submitted to plane sustained shock waves at different pressure levels using a laboratory powder gun. Pressure signals are measured using manganin gauges inserted at several distances inside HE. The corresponding run-distances to detonation are determined using wedge test experiments where the plate impact is performed using a powder gun. Both HE exhibit a single detonation buildup curve in the distance - time diagram of shock-to-detonation transition. This feature seems a common shock-to-detonation behavior for composite HE without porosity. This behavior is also confirmed for a RDX - HTPB 85:15 based composite HE. Such a behavior is exploited to determine the heterogeneous reaction rate versus the shock pressure using a method based on the Cauchy-Riemann problem inversion. The reaction rate laws obtained allow to compute both run-distance to detonation and pressure signals.

  16. Economic Shocks and Subjective Well-Being: Evidence from a Quasi-Experiment

    DEFF Research Database (Denmark)

    Hariri, Jacob Gerner; Bjørnskov, Christian; Justesen, Mogens Kamp

    2016-01-01

    This paper examines how economic shocks affect individual well-being in developing countries. Using the case of a sudden and unanticipated currency devaluation in Botswana as a quasi-experiment, we examine how this monetary shock affects individuals’ evaluations of well-being. We do so by using...... micro-level survey data, which – incidentally – was collected in the days surrounding the devaluation. The chance occurrence of the devaluation during the time of the survey enables us to use pre-treatment respondents, surveyed before the devaluation, as approximate counterfactuals for post......-treatment respondents, surveyed after the devaluation. Our estimates show that the devaluation had a large and significantly negative effect on individuals’ evaluations of subjective well-being. These results suggest that macroeconomic shocks, such as unanticipated currency devaluations, may have significant short...

  17. First application experiments with the Stockholm compact soft x-ray microscope

    International Nuclear Information System (INIS)

    Bertilson, M; Hofsten, O von; Lindblom, M; Holmberg, A; Takman, P; Vogt, U; Hertz, H; Thieme, J

    2009-01-01

    Most soft x-ray microscopes operating in the water window (λ = 2.3 - 4.4 nm) rely on synchrotron radiation sources. In the future we believe scientists will use soft x-ray microscopes as one imaging tool among others in their own laboratory. For this purpose we have developed a full field soft x-ray microscope with a laser-plasma source compact enough to fit on an optical table. In this contribution we describe the current status of this microscope now featuring stable operation at λ = 3.37 nm or λ 2.48 nm. In-house fabricated single element zone plates offering the possibility to perform phase contrast imaging have been implemented. We also report on the first application experiments for compact soft x-ray microscopy, including results from studies of clay minerals and colloids existing in nature and results from phase optics experiments. Planned upgrades of the microscope include increasing the source brightness, implementing more efficient condenser optics, and installing a cryo sample stage for tomography. These improvements will open up for further applications, especially in the field of biological imaging.

  18. Development of a lower extremity wearable exoskeleton with double compact elastic module: preliminary experiments

    Directory of Open Access Journals (Sweden)

    Y. Long

    2017-08-01

    Full Text Available In this paper, a double compact elastic module is designed and implemented in the lower extremity exoskeleton. The double compact elastic module is composed of two parts, i.e., physical human robot interaction (pHRI measurement and the elastic actuation system (EAS, which are called proximal elastic module (PEM and distal elastic module (DEM respectively. The PEM is used as the pHRI information collection device while the DEM is used as the compliance device. A novel compact parallelogram-like structure based torsional spring is designed and developed. An iterative finite element analysis (FEA based optimization process was conducted to find the optimal parameters in the search space. In the PEM, the designed torsional spring has an outer circle with a diameter of 60 mm and an inner hole with a diameter of 12 mm, while in the DEM, the torsional spring has the outer circle with a diameter of 80 mm and the inner circle with a diameter of 16 mm. The torsional spring in the PEM has a thickness of 5 mm and a weight of 60 g, while that in the DEM has a thickness of 10 mm and a weight of 80 g. The double compact elastic module prototype is embedded in the mechanical joint directly. Calibration experiments were conducted on those two elastic modules to obtain the linear torque versus angle characteristic. The calibration experimental results show that this torsional spring in the PEM has a stiffness of 60.2 Nm rad−1, which is capable of withstanding a maximum torque of 4 Nm, while that in the DEM has a stiffness of 80.2 Nm rad−1, which is capable of withstanding a maximum torque of 30 Nm. The experimental results and the simulation data show that the maximum resultant errors are 6 % for the PEM and 4 % for the DEM respectively. In this paper, an assumed regression algorithm is used to learn the human motion intent (HMI based on the pHRI collection. The HMI is defined as the angular position of the human limb joint. A

  19. Upgrade of the Global Muon Trigger for the Compact Muon Solenoid experiment at CERN

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00356020; Widmann, Eberhard

    The Large Hadron Collider is a large particle accelerator at the CERN research laboratory, designed to provide particle physics experiments with collisions at unprecedented centre-of-mass energies. For its second running period both the number of colliding particles and their collision energy were increased. To cope with these more challenging conditions and maintain the excellent performance seen during the first running period, the Level-1 trigger of the Compact Muon Solenoid experiment --- a sophisticated electronics system designed to filter events in real-time --- was upgraded. This upgrade consisted of the complete replacement of the trigger electronics and a full redesign of the system's architecture. While the calorimeter trigger path now follows a time-multiplexed processing model where the entire trigger data for a collision are received by a single processing board, the muon trigger path was split into regional track finding systems where each newly introduced track finder receives data from all th...

  20. Bayesian optimal experimental design for the Shock-tube experiment

    International Nuclear Information System (INIS)

    Terejanu, G; Bryant, C M; Miki, K

    2013-01-01

    The sequential optimal experimental design formulated as an information-theoretic sensitivity analysis is applied to the ignition delay problem using real experimental. The optimal design is obtained by maximizing the statistical dependence between the model parameters and observables, which is quantified in this study using mutual information. This is naturally posed in the Bayesian framework. The study shows that by monitoring the information gain after each measurement update, one can design a stopping criteria for the experimental process which gives a minimal set of experiments to efficiently learn the Arrhenius parameters.

  1. Space Shuttle Program (SSP) Shock Test and Specification Experience for Reusable Flight Hardware Equipment

    Science.gov (United States)

    Larsen, Curtis E.

    2012-01-01

    As commercial companies are nearing a preliminary design review level of design maturity, several companies are identifying the process for qualifying their multi-use electrical and mechanical components for various shock environments, including pyrotechnic, mortar firing, and water impact. The experience in quantifying the environments consists primarily of recommendations from Military Standard-1540, Product Verification Requirement for Launch, Upper Stage, and Space Vehicles. Therefore, the NASA Engineering and Safety Center (NESC) formed a team of NASA shock experts to share the NASA experience with qualifying hardware for the Space Shuttle Program (SSP) and other applicable programs and projects. Several team teleconferences were held to discuss past experience and to share ideas of possible methods for qualifying components for multiple missions. This document contains the information compiled from the discussions

  2. Assessment of In Situ Time Resolved Shock Experiments at Synchrotron Light Sources*

    Science.gov (United States)

    Belak, J.; Ilavsky, J.; Hessler, J. P.

    2005-07-01

    Prior to fielding in situ time resolved experiments of shock wave loading at the Advanced Photon Source, we have performed feasibility experiments assessing a single photon bunch. Using single and poly-crystal Al, Ti, V and Cu shock to incipient spallation on the gas gun, samples were prepared from slices normal to the spall plane of thickness 100-500 microns. In addition, single crystal Al of thickness 500 microns was shocked to incipient spallation and soft recovered using the LLNL e-gun mini-flyer system. The e-gun mini-flyer impacts the sample target producing a 10's ns flat-top shock transient. Here, we present results for imaging, small-angle scattering (SAS), and diffraction. In particular, there is little SAS away from the spall plane and significant SAS at the spall plane, demonstrating the presence of sub-micron voids. * Use of the Advanced Photon Source was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-Eng-38 and work performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

  3. Planar compaction of ceramic powders with mining explosives

    International Nuclear Information System (INIS)

    Stuivinga, M.; Verbeek, H.J.; Carton, E.P.

    2000-01-01

    Shock compaction experiments of B 4 C powders have been performed using a planar configuration. The powders were contained between metal plates. On top of the upper plate, having a thickness of about 10 mm, was a layer of mining explosives. For this configuration, computer simulations have been performed with use of the hydrocode Autodyn. In comparison with the cylindrical compaction process the planar compaction process appears to be quite different. The reason is the very low detonation velocity of the used mining explosives (2-4 km/s), which is much lower than the sound and shock speeds of the steel plate, in combination with the relatively large thickness of the metal layer. As a result, the nature of the compaction process of the powder initially more resembles a quasi-static compaction process than a shock compaction process. Due to the quasi-static nature of the compaction, the pressure release in the powder after compression is very gradual. Therefore, no strong rarefaction waves leading to high tensile stresses in the compact arise. Flat plates (10x10 cm, 0.6-0.8 cm thick) of Al (20-30 vol %) infiltrated B 4 C have been fabricated using this configuration

  4. Study of a microstrip gas detector for the Compact Muon Solenoid experiment; Etude d`un detecteur a micropistes pour l`experience Compact Muon Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Clergeau, J F [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire

    1997-06-19

    The micro-strip gas chambers (MSGC) were realized due to the technological advances in the field of micro-electronics. The wire of usual gas counters is replaced in these detectors by metallic stripes as a periodic sequence of electrodes (anodes and cathodes) spaced by around 200 {mu}m. At a distance of 3 mm above the strip containing substrate, a metallic plane is placed, thus defining the gaseous room where the passage of a charged particle produces by ionization a primary electron signal collected by the detector anodes. Due to its granularity a MSGC can operate under very high particle fluxes since charge can be collected very rapidly. Also, the impact parameters can be determined with high accuracy due to the high space and time resolutions. The Compact Muon Solenoid (CMS) or the MSGC detectors planned to equip one of the experiments proposed for LHC should detect, in extreme operational conditions, the particle impacts in a 4 Tesla magnetic field, for around ten years and for a particle flux of around 10{sup 4} Hz/mm{sup 2}. The CMS detector is described in chapter 2. The operation principle and the problems encountered in the development of MSGC detectors are summarized in chapter 3. The chapter 4 is dedicated to the study of the performances of MSGCs in magnetic fields. In the chapters 5 to 7 the processing of the signal from detectors of this type is described, particularly, the performances of various ways of treat the signal in terms of detection efficiency and counting loads are presented.The chapter 8 presents the results obtained with the prototype obtained at IPNL while the chapter 9 gives the conclusions of the performed works. (author) 55 refs.

  5. Walter B. Cannon's World War I experience: treatment of traumatic shock then and now.

    Science.gov (United States)

    Ryan, Kathy L

    2018-06-01

    Walter B. Cannon (1871-1945), perhaps America's preeminent physiologist, volunteered for service with the Army Expeditionary Force (AEF) during World War I. He initially served with Base Hospital No. 5, a unit made up of Harvard clinicians, before moving forward to the front lines to serve at a casualty clearing station run by the British. During his time there, he performed research on wounded soldiers to understand the nature and causes of traumatic shock. Subsequently, Cannon performed animal experimentation on the causes of traumatic shock in the London laboratory of Dr. William Bayliss before being assigned to the AEF Central Medical Laboratory in Dijon, France, where he continued his experimental studies. During this time, he also developed and taught a curriculum on resuscitation of wounded soldiers to medical providers. Although primarily a researcher and teacher, Cannon also performed clinical duties throughout the war, serving with distinction under fire. After the war, Cannon wrote a monograph entitled Traumatic Shock (New York: Appleton, 1923), which encapsulated the knowledge that had been gained during the war, both from direct observation of wounded soldiers, as well as laboratory experimentation on the causes and treatment of traumatic shock. In his monograph, Cannon elucidates a number of principles concerning hemorrhagic shock that were later forgotten, only to be "rediscovered" during the current conflicts in Iraq and Afghanistan. This paper summarizes Cannon's wartime experiences and the knowledge gained concerning traumatic shock during World War I, with a comparison of current combat casualty care practices and knowledge to that which Cannon and his colleagues understood a century ago.

  6. Electron Microscopic Examination of Irradiated TRISO Coated Particles of Compact 6-3-2 of AGR-1 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Van Rooyen, Isabella Johanna [Idaho National Lab. (INL), Idaho Falls, ID (United States); Demkowicz, Paul Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States); Riesterer, Jessica Lori [Idaho National Lab. (INL), Idaho Falls, ID (United States); Miller, Brandon Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Janney, Dawn Elizabeth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ploger, Scott Arden [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2012-12-01

    The electron microscopic examination of selected irradiated TRISO coated particles of the AGR-1 experiment of fuel compact 6-3-2 are presented in this report. Compact 6-3-2 refers to the compact in Capsule 6 at level 3 of Stack 2. The fuel used in capsule 6 compacts, are called the “baseline” fuel as it is fabricated with refined coating process conditions used to fabricate historic German fuel, because of its excellent irradiation performance with UO2 kernels. The AGR-1 fuel is however made of low-enriched uranium oxycarbide (UCO). Kernel diameters are approximately 350 µm with a U-235 enrichment of approximately 19.7%. Compact 6-3-2 has been irradiated to 11.3% FIMA compact average burn-up with a time average, volume average temperature of 1070.2°C and with a compact average fast fluence of 2.38E21 n/cm

  7. Optoheterodyne Doppler measurements of the ballistic expansion of the products of the shock wave-induced surface destruction: Experiment and theory

    International Nuclear Information System (INIS)

    Andriyash, A. V.; Astashkin, M. V.; Baranov, V. K.; Golubinskii, A. G.; Irinichev, D. A.; Kondrat’ev, A. N.; Kuratov, S. E.; Mazanov, V. A.; Rogozkin, D. B.; Stepushkin, S. N.; Khatunkin, V. Yu.

    2016-01-01

    The results of optoheterodyne Doppler measurements of the ballistic expansion of the products of surface destruction under shock-wave loading are presented. The possibility of determining the physical characteristics of a rapidly flying dust cloud, including the microparticle velocities, the microparticle sizes, and the areal density of the dust cloud, is shown. A compact stand for performing experiments on shock-wave loading of metallic samples is described. Shock-wave loading is performed by a 100-µm-thick tantalum flyer plate accelerated to a velocity of 2.8 km/s. As the samples, lead plates having various thicknesses and the same surface roughness are used. At a shock-wave pressure of 31.5 GPa, the destruction products are solid microparticles about 50 µm in size. At a pressure of 42 and 88 GPa, a liquid-drop dust cloud with a particle size of 10–15 µm is formed. To interpret the spectral data on the optoheterodyne Doppler measurements of the expansion of the surface destruction products (spalled fragments, dust microparticles), a transport equation for the function of mutual coherence of a multiply scattered field is used. The Doppler spectra of a backscattered signal are calculated with the model developed for the dust cloud that appears when a shock wave reaches the sample surface at the parameters that are typical of an experimental situation. Qualitative changes are found in the spectra, depending on the optical thickness of the dust cloud. The obtained theoretical results are in agreement with the experimental data.

  8. Optoheterodyne Doppler measurements of the ballistic expansion of the products of the shock wave-induced surface destruction: Experiment and theory

    Energy Technology Data Exchange (ETDEWEB)

    Andriyash, A. V. [All-Russia Research Institute of Automatics (Russian Federation); Astashkin, M. V.; Baranov, V. K.; Golubinskii, A. G.; Irinichev, D. A. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (VNIIEF) (Russian Federation); Kondrat’ev, A. N., E-mail: an.kondratev@physics.msu.ru; Kuratov, S. E. [All-Russia Research Institute of Automatics (Russian Federation); Mazanov, V. A. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (VNIIEF) (Russian Federation); Rogozkin, D. B. [All-Russia Research Institute of Automatics (Russian Federation); Stepushkin, S. N.; Khatunkin, V. Yu. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (VNIIEF) (Russian Federation)

    2016-06-15

    The results of optoheterodyne Doppler measurements of the ballistic expansion of the products of surface destruction under shock-wave loading are presented. The possibility of determining the physical characteristics of a rapidly flying dust cloud, including the microparticle velocities, the microparticle sizes, and the areal density of the dust cloud, is shown. A compact stand for performing experiments on shock-wave loading of metallic samples is described. Shock-wave loading is performed by a 100-µm-thick tantalum flyer plate accelerated to a velocity of 2.8 km/s. As the samples, lead plates having various thicknesses and the same surface roughness are used. At a shock-wave pressure of 31.5 GPa, the destruction products are solid microparticles about 50 µm in size. At a pressure of 42 and 88 GPa, a liquid-drop dust cloud with a particle size of 10–15 µm is formed. To interpret the spectral data on the optoheterodyne Doppler measurements of the expansion of the surface destruction products (spalled fragments, dust microparticles), a transport equation for the function of mutual coherence of a multiply scattered field is used. The Doppler spectra of a backscattered signal are calculated with the model developed for the dust cloud that appears when a shock wave reaches the sample surface at the parameters that are typical of an experimental situation. Qualitative changes are found in the spectra, depending on the optical thickness of the dust cloud. The obtained theoretical results are in agreement with the experimental data.

  9. Characteristics of a Bulk High-Critical Temperature Superconductor Fabricated by the Shock Compaction Method: Possible Use as a Highly Sensitive Magnetic Sensor

    International Nuclear Information System (INIS)

    Fujita, H; Maeji, Y; Yamagata, K; Itoh, M; Kezuka, H; Kikuchi, M; Atou, T; Kawasaki, M; Fukuoka, K

    2006-01-01

    A magnetic sensor, constructed of bulk Bi-Pb-Sr-Ca-Cu-O (BPSCCO), was fabricated by use of the shock compaction method, employing a propellant gun-system, and then sintered under through use of an electronic furnace. The specimen as a magnetic sensor was maintained in the superconducting state at 77.4 K, under a current density J of approximately 40 A/cm 2 in the absence of an excitation magnetic field B ex . The superconducting state was then broken and the specimen exposed to a B ex value of 40x10 -4 T. That is, the resistance R meas of the specimen occurred when exposed to 40x10 -4 T under a constant J of 40 A/cm 2 . The magnetic sensitivity S of the specimen was approximately 13 %/(10 -4 T) over the range of measurement of the magnetic field B meas from 0 to ±5x10 -4 T, under a constant 40x10 -4 T for the value of B ex , being approximately 13 times greater than that of a giant magnetoresistance (GMR) sensor. It was, consequently, determined that it was possible to apply the bulk BPSCCO specimen as a highly sensitive magnetic sensor

  10. Characteristics of a Bulk High-Critical Temperature Superconductor Fabricated by the Shock Compaction Method: Possible Use as a Highly Sensitive Magnetic Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H [Interdisci. Grad. School of Sci. and Engi., Grad. School of Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan); Maeji, Y [Interdisci. Grad. School of Sci. and Engi., Grad. School of Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan); Yamagata, K [Relia. Eval. Technol. Center, Nitto Denko Corp., Onomichi, Hiroshima 722-0212 (Japan); Itoh, M [Interdisci. Grad. School of Sci. and Engi., Grad. School of Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan); Kezuka, H [Faculty of Bionics, Tokyo University of Technol., Hachioji, Tokyo 192-0982 (Japan); Kikuchi, M [Kansen Fukushi Research Center, Tohoku Fukushi University Sendai, Miyagi 989-3201 (Japan); Atou, T [Insti. for Mate. Research, Tohoku University Sendai, Miyagi 980-8577 (Japan); Kawasaki, M [Insti. for Mate. Research, Tohoku University Sendai, Miyagi 980-8577 (Japan); Fukuoka, K [Insti. for Mate. Research, Tohoku University Sendai, Miyagi 980-8577 (Japan)

    2006-06-01

    A magnetic sensor, constructed of bulk Bi-Pb-Sr-Ca-Cu-O (BPSCCO), was fabricated by use of the shock compaction method, employing a propellant gun-system, and then sintered under through use of an electronic furnace. The specimen as a magnetic sensor was maintained in the superconducting state at 77.4 K, under a current density J of approximately 40 A/cm{sup 2} in the absence of an excitation magnetic field B{sub ex}. The superconducting state was then broken and the specimen exposed to a B{sub ex} value of 40x10{sup -4} T. That is, the resistance R{sub meas} of the specimen occurred when exposed to 40x10{sup -4} T under a constant J of 40 A/cm{sup 2}. The magnetic sensitivity S of the specimen was approximately 13 %/(10{sup -4} T) over the range of measurement of the magnetic field B{sub meas} from 0 to {+-}5x10{sup -4} T, under a constant 40x10{sup -4} T for the value of B{sub ex}, being approximately 13 times greater than that of a giant magnetoresistance (GMR) sensor. It was, consequently, determined that it was possible to apply the bulk BPSCCO specimen as a highly sensitive magnetic sensor.

  11. A coupled THMC model of a heating and hydration laboratory experiment in unsaturated compacted FEBEX bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Samper, J.; Montenegro, L.; Fernandez, A.M.

    2010-05-01

    Unsaturated compacted bentonite is foreseen by several countries as a backfill and sealing material in high-level radioactive waste repositories. The strong interplays between thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes during the hydration stage of a repository call for fully coupled THMC models. Validation of such THMC models is prevented by the lack of comprehensive THMC experiments and the difficulties of experimental methods to measure accurately the chemical composition of bentonite porewater. We present here a non-isothermal multiphase flow and multicomponent reactive solute transport model for a deformable medium of a heating and hydration experiment performed on a sample of compacted FEBEX bentonite. Besides standard solute transport and geochemical processes, the model accounts for solute cross diffusion and thermal and chemical osmosis. Bentonite swelling is solved with a state-surface approach. The THM model is calibrated with transient temperature, water content and porosity data measured at the end of the experiment. The reactive transport model is calibrated with porewater chemical data derived from aqueous extract data. Model results confirm that thermal osmosis is relevant for the hydration of FEBEX bentonite while chemical osmosis can be safely neglected. Dilution and evaporation are the main processes controlling the concentration of conservative species. Dissolved cations are mostly affected by calcite dissolution-precipitation and cation exchange reactions. Dissolved sulphate is controlled by gypsum/anhydrite dissolution-precipitation. pH is mostly buffered by protonation/deprotonation via surface complexation. Computed concentrations agree well with inferred aqueous extract data at all sections except near the hydration boundary where cation data are affected by a sampling artifact. The fit of Cl{sup -} data is excellent except for the data near the heater. The largest deviations of the model from inferred aqueous

  12. Interferometric windows characterization up to 450 K for shock wave experiments: Hugoniot curves and refractive index

    Directory of Open Access Journals (Sweden)

    Godefroit J.-L.

    2012-08-01

    Full Text Available Conventional shock wave experiments need interferometric windows in order to determine the equation of state of a large variety of metals. Lithium fluoride (LiF and sapphire are extensively used for that purpose because their optical transparencies enable the optical diagnostics at interfaces under a given range of shock pressure. In order to simulate and analyse the experiments it is necessary to gather a correct knowledge of the optical and mechanical properties of these windows. Therefore, our window supplies are systematically characterized and an experimental campaign under shock loading is conducted. Our preliminary work on LiF windows at 532 nm is in good agreement with literature data at room temperature and the new characterization at 450 K enables a better interpretation of our preheated target experiments. It confirms the predominant effect of density on optical properties under pressure and temperature. The present work demonstrates that the initial density determination is a key point and that the uncertainties need to be improved. For that purpose, complementary experiments are conducted on LiF windows with simplified target designs and enriched diagnostics, coupling VISAR (532 nm and PdV (1550 nm diagnostics. Furthermore, a similar campaign is conducted on sapphire windows with symmetric impact configuration.

  13. Optimal Design and Model Validation for Combustion Experiments in a Shock Tube

    KAUST Repository

    Long, Quan

    2014-01-06

    We develop a Bayesian framework for the optimal experimental design of the shock tube experiments which are being carried out at the KAUST Clean Combustion Center. The unknown parameters are the pre-exponential parameters and the activation energies in the reaction rate functions. The control parameters are the initial hydrogen concentration and the temperature. First, we build a polynomial based surrogate model for the observable related to the reactions in the shock tube. Second, we use a novel MAP based approach to estimate the expected information gain in the proposed experiments and select the best experimental set-ups corresponding to the optimal expected information gains. Third, we use the synthetic data to carry out virtual validation of our methodology.

  14. Thermal shock experiment analysis, the use of crack arrest toughness measurements

    International Nuclear Information System (INIS)

    Miannay, D.; Pellissier-Tanon, A.; Chavaillard, J.P.

    1984-06-01

    The main purpose of thermal shock experiment is to assess the procedure codified in the ASME XI appendix 1 or RCC-M-B appendix ZG, and allow comparisons with numerical simulations. The analysis of the integrity of the PWR vessel belt line under accidental transients is based on reference curves. The test-piece is a cylinder of SA 508 cl.3 steel. Arrest toughness measured agrees with reference curve

  15. The Shock/Shear platform for planar radiation-hydrodynamics experiments on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Doss, F. W., E-mail: fdoss@lanl.gov; Kline, J. L.; Flippo, K. A.; Perry, T. S.; DeVolder, B. G.; Tregillis, I.; Loomis, E. N.; Merritt, E. C.; Murphy, T. J.; Welser-Sherrill, L.; Fincke, J. R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2015-05-15

    An indirectly-driven shock tube experiment fielded on the National Ignition Facility (NIF) was used to create a high-energy-density hydrodynamics platform at unprecedented scale. Scaling up a shear-induced mixing experiment previously fielded at OMEGA, the NIF shear platform drives 130 μm/ns shocks into a CH foam-filled shock tube (∼ 60 mg/cc) with interior dimensions of 1.5 mm diameter and 5 mm length. The pulse-shaping capabilities of the NIF are used to extend the drive for >10 ns, and the large interior tube volumes are used to isolate physics-altering edge effects from the region of interest. The scaling of the experiment to the NIF allows for considerable improvement in maximum driving time of hydrodynamics, in fidelity of physics under examination, and in diagnostic clarity. Details of the experimental platform and post-shot simulations used in the analysis of the platform-qualifying data are presented. Hydrodynamic scaling is used to compare shear data from OMEGA with that from NIF, suggesting a possible change in the dimensionality of the instability at late times from one platform to the other.

  16. Large-scale thermal-shock experiments with clad and unclad steel cylinders

    International Nuclear Information System (INIS)

    Cheverton, R.D.

    1992-01-01

    Flaw behavior trends associated with pressurized-thermal-shock (PTS) loading of pressurized-water-reactor pressure vessels have been under investigation at the Oak Ridge National Laboratory for nearly 20 years. During that time, twelve thermal-shock experiments with thick-walled (152 mm) steel cylinders were conducted as a part of the investigations. The first eight experiments were conducted with unclad cylinders initially containing shallow (8--19 mm) two-dimensional and semicircular inner-surface flaws. These experiments demonstrated, in good agreement with linear elastic fracture mechanics, crack initiation and arrest, a series of initiation/arrest events with deep penetration of the wall, long crack jumps, arrest with the stress intensity factor (K I ) increasing with crack depth, extensive surface extension of an initially short and shallow (semicircular) flaw, and warm prestressing with K I ≤ 0. The remaining four experiments were conducted with clad cylinders containing initially shallow (19--24 mm) semielliptical subclad and surface flaws at the inner surface. In the first of these experiments one of six equally spaced (60 degrees) open-quotes identicalclose quotes subclad flaws extended nearly the length of the cylinder (1,220 mm) beneath the cladding (no crack extension into the cladding) and nearly 50% of the wall, radially. For the final experiment, four of the semielliptical subclad flaws that had not propagated previously were converted to surface flaws, and they experienced extensive extension beneath the cladding with no cracking of the cladding. Information from this series of thermal-shock experiments is being used in the evaluation of the PTS issue

  17. Water diffusion through compacted clays analyzed by neutron scattering and tracer experiments

    International Nuclear Information System (INIS)

    Gonzalez Sanchez, F.

    2007-11-01

    using various methodologies to better interpret the dynamic results. Parameters such as particle size, layer spacing, chemical composition, external and total surfaces and porosity were determined. The fundamental transport processes in compacted clay systems were studied over a broad range of temperatures, combining microscopic diffusion experiments (T ∼ 98 to -23 o C) with macroscopic measurements (T ∼ 70 to 0 o C). Moreover, the freezing behaviour of water in compacted clays and its dynamical properties in the supercooled regime were also investigated using microscopic techniques such as neutron scattering, time of flight and backscattering techniques. Such knowledge contributes to develop simplified models for water (and possibly also solute) transport through clays, as they will be used to assess the performance of radioactive waste repositories. From this point of view, it can be beneficial for the safety of radioactive waste repositories and thus the protection of the environment

  18. Water diffusion through compacted clays analyzed by neutron scattering and tracer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Sanchez, F

    2007-11-15

    samples using various methodologies to better interpret the dynamic results. Parameters such as particle size, layer spacing, chemical composition, external and total surfaces and porosity were determined. The fundamental transport processes in compacted clay systems were studied over a broad range of temperatures, combining microscopic diffusion experiments (T {approx} 98 to -23 {sup o}C) with macroscopic measurements (T {approx} 70 to 0 {sup o}C). Moreover, the freezing behaviour of water in compacted clays and its dynamical properties in the supercooled regime were also investigated using microscopic techniques such as neutron scattering, time of flight and backscattering techniques. Such knowledge contributes to develop simplified models for water (and possibly also solute) transport through clays, as they will be used to assess the performance of radioactive waste repositories. From this point of view, it can be beneficial for the safety of radioactive waste repositories and thus the protection of the environment.

  19. Enhancing Student International Awareness and Global Competency through Compact International Experience Courses

    Science.gov (United States)

    Jacobitz, Frank; Schubert, Thomas

    2013-11-01

    Short-term, study-abroad, elective engineering courses were developed in order to raise the international awareness and global competency of engineering students. These Compact International Experience (CIE) courses were taught in response to a strong student desire for engineering study abroad courses and an effort by the home institution to internationalize its curriculum. An assessment of repeat offerings of two three-semester-unit courses on Topics in Fluid Mechanics and Advanced Electronic Circuit Design in a three-week time frame in France and Australia was performed. The goals of the two CIE courses are an effective teaching of their respective technical content as well as a student understanding of the cultural environment and the impact of engineering solutions from a global and societal viewpoint. In the repeat offerings, increased interaction with local industry was an additional goal. The CIE courses were assessed through surveys completed at the beginning and end of the courses, weekly student reflection papers, course evaluations, and formalized instructor observations. Based on the assessment performed, the two CIE courses have been found to be a valuable approach in the delivery of engineering technical electives combined with an international experience.

  20. A 3-MA compact-toroid-plasma-flow-switched plasma focus demonstration experiment on Shiva Star

    Energy Technology Data Exchange (ETDEWEB)

    Kiuttu, G F; Degnan, J H [Phillips Lab., Kirtland AFB, NM (United States). High Energy Sources Div.; Graham, J D [Maxwell Labs., Albuquerque, NM (United States); and others

    1997-12-31

    A novel dense plasma focus experiment using the Shiva Star capacitor bank is described. The experiment uses a compact toroid (CT) magnetized plasma flow switch (PFS) to initiate the focus implosion. The CT armature stably and reproducibly translates up to 3 MA from the vacuum feed region through coaxial electrodes to the gas puff central load. The inertia of the 1 mg CT and the work that must be done in compressing the internal magnetic fields during the translation provide a delay in current delivery to the pinch of 5 - 10 {mu}s, which matches the bank quarter cycle time relatively well. Effectiveness of the current delivery was monitored primarily by inductive probes in the PFS region, fast photography of the focus, and x-ray and neutron measurements of the pinch. K shell x-ray yields using neon gas were as high as 1 kJ, and 10{sup 8} neutrons were produced in a deuterium gas focus. (author). 4 figs., 10 refs.

  1. A 3-MA compact-toroid-plasma-flow-switched plasma focus demonstration experiment on Shiva Star

    International Nuclear Information System (INIS)

    Kiuttu, G.F.; Degnan, J.H.

    1996-01-01

    A novel dense plasma focus experiment using the Shiva Star capacitor bank is described. The experiment uses a compact toroid (CT) magnetized plasma flow switch (PFS) to initiate the focus implosion. The CT armature stably and reproducibly translates up to 3 MA from the vacuum feed region through coaxial electrodes to the gas puff central load. The inertia of the 1 mg CT and the work that must be done in compressing the internal magnetic fields during the translation provide a delay in current delivery to the pinch of 5 - 10 μs, which matches the bank quarter cycle time relatively well. Effectiveness of the current delivery was monitored primarily by inductive probes in the PFS region, fast photography of the focus, and x-ray and neutron measurements of the pinch. K shell x-ray yields using neon gas were as high as 1 kJ, and 10 8 neutrons were produced in a deuterium gas focus. (author). 4 figs., 10 refs

  2. Modular coil design developments for the National Compact Stellarator Experiment (NCSX)

    International Nuclear Information System (INIS)

    Williamson, D.; Brooks, A.; Brown, T.; Chrzanowski, J.; Cole, M.; Fan, H.-M.; Freudenberg, K.; Fogarty, P.; Hargrove, T.; Heitzenroeder, P.; Lovett, G.; Miller, P.; Myatt, R.; Nelson, B.; Reiersen, W.; Strickler, D.

    2005-01-01

    The National Compact Stellarator Experiment (NCSX) is a quasi-axisymmetric facility that combines the high beta and good confinement features of an advanced tokamak with the low current, disruption-free characteristics of a stellarator. The experiment is based on a three field-period plasma configuration with an average major radius of 1.4 m, a minor radius of 0.3 m, and a toroidal magnetic field on axis of up to 2 T. The modular coils are one set in a complex assembly of four coil systems that surround the highly shaped plasma. There are six, each of three coil types in the assembly for a total of 18 modular coils. The coils are constructed by winding copper cable onto a cast stainless steel winding form that has been machined to high accuracy, so that the current center of the winding pack is within ±1.5 mm of its theoretical position. The modular coils operate at a temperature of 80 K and are subjected to rapid heating and stress during a pulse. At this time, the project has completed construction of several prototype components which validate the fabrication and inspection processes that are planned for the production coils. In addition, some advanced techniques for error-field compensation and assembly simulation using computer-aided design (CAD) have been developed

  3. A retrospective analysis of compact fluorescent lamp experience curves and their correlations to deployment programs

    International Nuclear Information System (INIS)

    Smith, Sarah Josephine; Wei, Max; Sohn, Michael D.

    2016-01-01

    Experience curves are useful for understanding technology development and can aid in the design and analysis of market transformation programs. Here, we employ a novel approach to create experience curves, to examine both global and North American compact fluorescent lamp (CFL) data for the years 1990–2007. We move away from the prevailing method of fitting a single, constant, exponential curve to data and instead search for break points where changes in the learning rate may have occurred. Our analysis suggests a learning rate of approximately 21% for the period of 1990–1997, and 51% and 79% in global and North American datasets, respectively, after 1998. We use price data for this analysis; therefore our learning rates encompass developments beyond typical “learning by doing”, including supply chain impacts such as market competition. We examine correlations between North American learning rates and the initiation of new programs, abrupt technological advances, and economic and political events, and find an increased learning rate associated with design advancements and federal standards programs. Our findings support the use of segmented experience curves for retrospective and prospective technology analysis, and may imply that investments in technology programs have contributed to an increase of the CFL learning rate. - Highlights: • We develop a segmented regression technique to estimate historical CFL learning curves. • CFL experience curves do not have a constant learning rate. • CFLs exhibited a learning rate of approximately 21% from 1990 to 1997. • The CFL learning rate significantly increased after 1998. • Increased CFL learning rate is correlated to technology deployment programs.

  4. Formalising and analysing the control software of the Compact Muon Solenoid Experiment at the Large Hadron Collider

    NARCIS (Netherlands)

    Hwong, Y.L.; Keiren, J.J.A.; Kusters, V.J.J.; Leemans, S.J.J.; Willemse, T.A.C.

    2013-01-01

    The control software of the CERN Compact Muon Solenoid experiment contains over 27 500 finite state machines. These state machines are organised hierarchically: commands are sent down the hierarchy and state changes are sent upwards. The sheer size of the system makes it virtually impossible to

  5. Composition of the earth's atmosphere by shock-layer radiometry during the PAET entry probe experiment.

    Science.gov (United States)

    Whiting, E. E.; Arnold, J. O.; Page, W. A.; Reynolds, R. M.

    1973-01-01

    A determination of the composition of the earth's atmosphere obtained from onboard radiometer measurements of the spectra emitted from the bow shock layer of a high-speed entry probe is reported. The N2, O2, CO2, and noble gas concentrations in the earth's atmosphere were determined to good accuracy by this technique. The results demonstrate unequivocally the feasibility of determining the composition of an unknown planetary atmosphere by means of a multichannel radiometer viewing optical emission from the heated atmospheric gases in the region between the bow shock wave and the vehicle surface. The spectral locations in this experiment were preselected to enable the observation of CN violet, N2(+) first negative and atomic oxygen emission at 3870, 3910, and 7775 A, respectively. The atmospheric gases were heated and compressed by the shock wave to a peak temperature of about 6100 K and a corresponding pressure of 0.4 atm. Complete descriptions of the data analysis technique and the onboard radiometer and its calibration are given.

  6. Shock and vibration protection of submerged jet impingement cooling systems: Theory and experiment

    International Nuclear Information System (INIS)

    Haji Hosseinloo, Ashkan; Tan, Siow Pin; Yap, Fook Fah; Toh, Kok Chuan

    2014-01-01

    In the recent years, advances in high power density electronics and computing systems have pushed towards more advanced thermal management technologies and higher-capacity cooling systems. Among different types of cooling systems, jet impingement technology has gained attention and been widely used in different industries for its adaptability, cooling uniformity, large heat capacity, and ease of its localization. However, these cooling systems may not function properly in dynamically harsh environment inherent in many applications such as land, sea and air transportation. In this research article, a novel double-chamber jet impingement cooling system is fabricated and its performance is studied in harsh environment. Using the authors' previous studies, isolators with optimum properties are selected to ruggedize the chassis containing the cooling chamber against shock and random vibration. Experiments are conducted on both hard-mounted and isolated chassis and the cooling performance of the system is assessed using the inlet, and impingement surface temperatures of the cooling chamber. The experimental results show the isolation system prevents any failure that otherwise would occur, and also does not compromise the thermal performance of the system. - Highlights: • A novel double-chamber jet impingement cooling system was designed and fabricated. • Comprehensive set of random vibration and shock tests are conducted. • The isolation system proved to protect the cooling system properly against mechanical failure. • Cooling system performance was not significantly affected by the input random vibration and shock

  7. High temperature shock tube experiments and kinetic modeling study of diisopropyl ketone ignition and pyrolysis

    KAUST Repository

    Barari, Ghazal

    2017-03-10

    Diisopropyl ketone (DIPK) is a promising biofuel candidate, which is produced using endophytic fungal conversion. In this work, a high temperature detailed combustion kinetic model for DIPK was developed using the reaction class approach. DIPK ignition and pyrolysis experiments were performed using the UCF shock tube. The shock tube oxidation experiments were conducted between 1093K and 1630K for different reactant compositions, equivalence ratios (φ=0.5–2.0), and pressures (1–6atm). In addition, methane concentration time-histories were measured during 2% DIPK pyrolysis in argon using cw laser absorption near 3400nm at temperatures between 1300 and 1400K near 1atm. To the best of our knowledge, current ignition delay times (above 1050K) and methane time histories are the first such experiments performed in DIPK at high temperatures. Present data were used as validation targets for the new kinetic model and simulation results showed fair agreement compared to the experiments. The reaction rates corresponding to the main consumption pathways of DIPK were found to have high sensitivity in controlling the reactivity, so these were adjusted to attain better agreement between the simulation and experimental data. A correlation was developed based on the experimental data to predict the ignition delay times using the temperature, pressure, fuel concentration and oxygen concentration.

  8. High temperature shock tube experiments and kinetic modeling study of diisopropyl ketone ignition and pyrolysis

    KAUST Repository

    Barari, Ghazal; Pryor, Owen; Koroglu, Batikan; Sarathy, Mani; Masunov, Artë m E.; Vasu, Subith S.

    2017-01-01

    Diisopropyl ketone (DIPK) is a promising biofuel candidate, which is produced using endophytic fungal conversion. In this work, a high temperature detailed combustion kinetic model for DIPK was developed using the reaction class approach. DIPK ignition and pyrolysis experiments were performed using the UCF shock tube. The shock tube oxidation experiments were conducted between 1093K and 1630K for different reactant compositions, equivalence ratios (φ=0.5–2.0), and pressures (1–6atm). In addition, methane concentration time-histories were measured during 2% DIPK pyrolysis in argon using cw laser absorption near 3400nm at temperatures between 1300 and 1400K near 1atm. To the best of our knowledge, current ignition delay times (above 1050K) and methane time histories are the first such experiments performed in DIPK at high temperatures. Present data were used as validation targets for the new kinetic model and simulation results showed fair agreement compared to the experiments. The reaction rates corresponding to the main consumption pathways of DIPK were found to have high sensitivity in controlling the reactivity, so these were adjusted to attain better agreement between the simulation and experimental data. A correlation was developed based on the experimental data to predict the ignition delay times using the temperature, pressure, fuel concentration and oxygen concentration.

  9. Compact toroid challenge experiment with the increasing in the energy input into plasma and the level of trapped magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Romadanov, I.V.; Ryzhkov, S.V., E-mail: ryzhkov@power.bmstu.ru

    2014-12-15

    Highlights: • Compact torus formation method with high level of magnetic flux is proposed. • A compact torus is produced in a theta-pinch-coil with pulse mode of operation. • Key feature is a pulse of current in an axial direction. • We report a level of linked magnetic flux is higher than theta-pinch results. - Abstract: The present work reports on compact toroid hydrogen plasma creation by means of a specially designed discharge system and results of magnetic fields introduction. Experiments in the compact toroid challenge (CTC) device at P.N. Lebedev Physical Institute (FIAN) have been conducted since 2005. The CTC device differs from the conventional theta-pinch formation in the use of an axial current for enhanced efficiency. We have used a novel technique to maximize the flux linked to the plasma. The purpose of this method is to increase the energy input into the plasma and the level of trapped magnetic flux using an additional toroidal magnetic field. A study of compact torus formation with axial and toroidal currents was done and a new method is proposed and implemented.

  10. Overview of recent results and future plans on the Compact Toroidal Hybrid experiment

    Science.gov (United States)

    Maurer, D. A.; Archmiller, M. C.; Cianciosa, M. R.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Knowlton, S. F.; Ma, X.; Massidda, S.; Pandya, M. D.; Roberds, N. A.; Traverso, P. J.

    2015-11-01

    Goals of the Compact Toroidal Hybrid (CTH) experiment are to: (1) investigate the dependence of plasma disruptive behavior on the level of applied 3D magnetic shaping, (2) test and advance 3D computational modeling tools in strongly shaped plasmas, and (3) study the implementation of a new island divertor. Progress towards these goals and other developments are summarized. The disruptive density limit is observed to exceed the Greenwald limit as the vacuum transform is increased, but a threshold for disruption avoidance is not observed. Low q operation is routine, with low q disruptions avoided when the vacuum transform is raised to the value of 0.07 or above. Application of vacuum transform has been demonstrated to reduce and eliminate the vertical drift of elongated discharges that would otherwise be vertically unstable. Current efforts at improved equilibrium reconstruction and diagnostic development will beoverviewed. NIMROD is used to model the current ramp phase of CTH and 3D shaped sawtooth behavior. An island divertor design has begun with connection length studies and initial EMC3-Eirene results to model energy deposition on divertor plates located in an edge 1/3 island. This work is supported by U.S. Department of Energy Grant No. DE- FG02-00ER54610.

  11. The silicon sensors for the Inner Tracker of the Compact Muon Solenoid Experiment

    International Nuclear Information System (INIS)

    Krammer, M.

    2003-01-01

    Full text: The Inner Tracker of the Compact Muon Solenoid Experiment, at present under construction, will consist of more than 24000 silicon strip sensors arranged in 10 central concentric layers and 2 X 9 discs at both ends. The total sensitive silicon area will exceed 200 m 2 . The silicon sensors are produced in various thicknesses and geometries. Each sensor has 512 or 768 implanted strips which will allow to measure the position of traversing high energy charged particles. This paper a short overview of the CMS tracker system. Subsequently the design of the silicon sensors is explained with special emphasis on the radiation hardness and on the high voltage stability of the sensors. Two companies share the production of these sensors. The quality of the sensors is extensively checked by several laboratories associated with CMS. Important electrical parameters are measured on the sensors themselves. In addition, dedicated test structures were designed by CMS which allow the monitoring of many parameters sensitive to the production process. By May 2003 about 3000 sensors were delivered and a large fraction of these sensors and tests structures was measured. A summary of these measurements will be given and the main results will be discussed

  12. U.S.S.R. eyes role in U.S. compact tokamak ignition experiment

    International Nuclear Information System (INIS)

    Crawford, M.

    1987-01-01

    Physicists working on nuclear fusion in the Soviet Union want to participate in America's next experiment, the Compact Ignition Tokamak (CIT). Soviet scientists first mentioned the idea to Department of Energy (DOE) officials last spring but have not put forth any formal proposal. Department officials, however, say the Soviets are serious about working with the US on the project. From the outset, however, efforts to work more closely with the Soviets on fusion research have been stifled by concerns within the Administration that sensitive Western technology will be transferred to the Soviet Union's military establishment. The key to Soviet participation in CIT may depend on what they can contribute materially, as well as intellectually to the US project. Soviet scientists are currently defining how their country might contribute to the CIT, and they could submit a proposal to the US within a year. Indeed, the technology transfer issue has made DOE and State Department officials reluctant to discuss the possibility of the Soviet Union taking a role in the CIT. They fear that the concept will be rejected on ideological grounds before the merits of a Soviet proposal can be considered

  13. An Experiment on the Carbonization of Fuel Compact Matrix Graphite for HTGR

    International Nuclear Information System (INIS)

    Lee, Young Woo; Kim, Joo Hyoung; Cho, Moon Sung

    2012-01-01

    The fuel element for HTGR is manufactured by mixing coated fuel particles with matrix graphite powder and forming into either pebble type or cylindrical type compacts depending on their use in different HTGR cores. The coated fuel particle, the so-called TRISO particle, consists of 500-μm spherical UO 2 particles coated with the low density buffer Pyrolytic Carbon (PyC) layer, the inner and outer high density PyC layer and SiC layer sandwiched between the two inner and outer PyC layers. The coated TRISO particles are mixed with a properly prepared matrix graphite powder, pressed into a spherical shape or a cylindrical compact, and finally heat-treated at about 1800 .deg. C. These fuel elements can have different sizes and forms of compact. The basic steps for manufacturing a fuel element include preparation of graphite matrix powder, over coating the fuel particles, mixing the fuel particles with a matrix powder, carbonizing green compact, and the final high-temperature heat treatment of the carbonized fuel compact. The carbonization is a process step where the binder that is incorporated during the matrix graphite powder preparation step is evaporated and the residue of the binder is carbonized during the heat treatment at about 1073 K, In order to develop a fuel compact fabrication technology, and for fuel matrix graphite to meet the required material properties, it is of extreme importance to investigate the relationship among the process parameters of the matrix graphite powder preparation, fabrication parameters of fuel element green compact and the carbonization condition, which has a strong influence on further steps and the material properties of fuel element. In this work, the carbonization behavior of green compact samples prepared from the matrix graphite powder mixtures with different binder materials was investigated in order to elucidate the behavior of binders during the carbonization heat treatment by analyzing the change in weight, density and its

  14. Status of the variable momentum compaction storage ring experiment in SPEAR

    International Nuclear Information System (INIS)

    Tran, P.; Amiry, A.; Pellegrini, C.

    1993-01-01

    Variable momentum compaction lattices have been proposed for electron-positron colliders and synchrotron radiation sources to control synchrotron tune and bunch length. To address questions of single particle stability limits, a study has been initiated to change the SPEAR lattice into a variable momentum compaction configuration for experimental investigation of the beam dynamics. In this paper, we describe a model-based method used to transform SPEAR from the injection lattice to the low momentum compaction configuration. Experimental observations of the process are reviewed

  15. Granular compaction and stretched exponentials - Experiments and a numerical stochastic model

    Directory of Open Access Journals (Sweden)

    Nicolas Maxime

    2017-01-01

    Full Text Available We present a stochastic model to investigate the compaction kinetics of a granular material submitted to vibration. The model is compared to experimental results obtained with glass beads and with a cohesive powder. We also propose a physical interpretation of the characteristic time τ and the exponent β of the stretched exponential function widely used to represent the granular compaction kinetics, and we show that the characteristic time is proportional to the number of grains to move. The exponent β is expressed as a logarithmic compaction rate.

  16. High β experiment and confinement regimes in a compact helical system

    International Nuclear Information System (INIS)

    Matsuoka, K.; Okamura, S.; Nishimura, K.; Tsumori, K.; Akiyama, R.; Yamada, H.; Sakakibara, S.; Lazaros, A.; Xu, J.; Ida, K.; Tanaka, K.; Morisaki, T.; Morita, S.; Arimoto, H.; Fujiwara, M.; Idei, H.; Iguchi, H.; Kaneko, O.; Kawamoto, T.; Kubo, S.; Kuroda, T.; Motojima, O.; Ozaki, T.; Pustovitov, V.D.; Sagara, A.; Takahashi, C.; Toi, K.; Watari, T.; Yamada, I.

    1995-01-01

    A volume-averaged equilibrium β value left angle β eq right angle of 2.14% is achieved in a compact helical system using two neutral beam lines with balanced injection and intense wall conditioning with Ti gettering. This value is the highest β value realized so far in helical systems. Reheat mode, where the stored energy increases after turn-off of a strong gas puff, is employed in the experiment. Discharge conditions are as follows: B t =0.61T; beam power through the port, 1.1MW (coinjection) and 0.8MW (counterinjection); line-averaged electron density n e =6.5x10 13 cm -3 . Amplitudes of magnetic fluctuations integrated over the frequency range from 3kHz to 100kHz become saturated at left angle β eq right angle higher than 1%. Dominant coherent modes are m/n=2/1 and 1/1 when left angle β eq right angle is lower and higher respectively than 1%. Dependence of the energy confinement time τ E on n e (up to 8x10 13 cm -3 ) and B t (from 0.6 to 1.8T) is also studied in this high β experiment. When the density increases τ E degrades compared with the LHD scaling; the density dependence exhibits Bohm-like behaviour. On the contrary, τ E scales as B ∼0.75 t , which is rather close to the LHD scaling (gyro-Bohm-like behaviour). ((orig.))

  17. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Robey, H F; Munro, D H; Spears, B K; Marinak, M M; Jones, O S; Patel, M V; Haan, S W; Salmonson, J D; Landen, O L [Lawrence Livermore National Laboratory, Livermore, CA (United States); Boehly, T R [Laboratory for Laser Energetics, Rochester, NY (United States); Nikroo, A [General Atomics, San Diego, CA (United States)], E-mail: robey1@llnl.gov

    2008-05-15

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of {<=} +/- 100ps. To meet these stringent requirements, dedicated tuning experiments are being planned to measure and adjust the shock timing on NIF. These tuning experiments will be performed in a modified hohlraum geometry, where a re-entrant Au cone is added to the standard NIF hohlraum to provide optical diagnostic (VISAR and SOP) access to the shocks as they break out of the ablator. This modified geometry is referred to as the 'keyhole' hohlraum and introduces a geometric difference between these tuning-experiments and the full ignition geometry. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum.

  18. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    International Nuclear Information System (INIS)

    Robey, H F; Munro, D H; Spears, B K; Marinak, M M; Jones, O S; Patel, M V; Haan, S W; Salmonson, J D; Landen, O L; Boehly, T R; Nikroo, A

    2008-01-01

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of ≤ +/- 100ps. To meet these stringent requirements, dedicated tuning experiments are being planned to measure and adjust the shock timing on NIF. These tuning experiments will be performed in a modified hohlraum geometry, where a re-entrant Au cone is added to the standard NIF hohlraum to provide optical diagnostic (VISAR and SOP) access to the shocks as they break out of the ablator. This modified geometry is referred to as the 'keyhole' hohlraum and introduces a geometric difference between these tuning-experiments and the full ignition geometry. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum

  19. A validation study for the gas migration modelling of the compacted bentonite using existing experiment data

    International Nuclear Information System (INIS)

    Tawara, Y.; Mori, K.; Tada, K.; Shimura, T.; Sato, S.; Yamamoto, S.; Hayashi, H.

    2010-01-01

    Document available in extended abstract form only. After the field-scaled Gas Migration Test (GMT) was carried out at Grimsel Test Site (GTS) in Switzerland from 1997 through 2005, a study on advanced gas migration modelling has been conducted as a part of R and D programs of the RWMC (Radioactive Waste Management funding and Research Center) to evaluate long-term behaviour of the Engineered Barrier System (EBS) for the TRU waste disposal system in Japan. One of main objectives of this modelling study is to provide the qualified models and parameters in order to predict long-term gas migration behaviour in compacted bentonite. In addition, from a perspective of coupled THMC (Thermal, Hydrological, Mechanical and Chemical) processes, the specific processes which may have considerable impact to the gas migration behaviour are discussed by means of scoping calculations. Literature survey was conducted to collect experimental data related to gas migration in compacted bentonite in order to discuss an applicability of the existing gas migration models in the bentonite. The well-known flow rate controlled-gas injection experiment by Horseman, et al. and the pressure-controlled-gas injection test using several data with wide range of clay density and water content by Graham, et al, were selected. These literatures show the following characteristic behaviour of gas migration in high compacted and water-saturated bentonite. The observed gas flow rate from the outlet in the experiment by Horseman et al. was numerically reproduced by using the different conceptual models and computer codes, and then an applicability of the models and the identified key parameters such as relative permeability and capillary pressure were discussed. Helium gas was repeatedly injected into fully water-saturated and isotropically consolidated MX-80 bentonite (dry density: 1.6 Mg/m 3 ) in the experiment. One of the most important conclusions from this experiment is that it's impossible for

  20. Pressurized-thermal-shock experiments: PTSE-1 results and PTSE-2 plans

    International Nuclear Information System (INIS)

    Bryan, R.H.; Nanstad, R.K.; Wanner, R.; Merkle, J.G.; Robinson, G.C.; Whitman, G.D.

    1985-01-01

    The first pressurized-thermal-shock experiment (PTSE-1) was performed with a vessel with a 1-m-long flaw in a plug of specially tempered steel having the composition of SA-508 forging steel. The second experiment (PTSE-2) will have a similar arrangement, but the material in which the flaw will be implanted is being prepared to have low tearing resistance. Special tempering of a 2 1/4 Cr - 1 Mo steel plate has been shown to induce a low Charpy impact energy in the upper-shelf temperature range. The purpose of PTSE-2 is to investigate the fracture behavior of low-upper-shelf material in a vessel under the combined loading of concurrent pressure and thermal shock. The primary objective of the experimental plan is to induce a rapidly propagating cleavage fracture under conditions that are likely to induce a ductile tearing instability at the time of arrest of the cleavage fracture. The secondary objective of the test is to extend the range of the investigation of warm prestressing. 11 figs

  1. Study of a microstrip gas detector for the Compact Muon Solenoid experiment

    International Nuclear Information System (INIS)

    Clergeau, J. F.

    1997-01-01

    The micro-strip gas chambers (MSGC) were realized due to the technological advances in the field of micro-electronics. The wire of usual gas counters is replaced in these detectors by metallic stripes as a periodic sequence of electrodes (anodes and cathodes) spaced by around 200 μm. At a distance of 3 mm above the strip containing substrate, a metallic plane is placed, thus defining the gaseous room where the passage of a charged particle produces by ionization a primary electron signal collected by the detector anodes. Due to its granularity a MSGC can operate under very high particle fluxes since charge can be collected very rapidly. Also, the impact parameters can be determined with high accuracy due to the high space and time resolutions. The Compact Muon Solenoid (CMS) or the MSGC detectors planned to equip one of the experiments proposed for LHC should detect, in extreme operational conditions, the particle impacts in a 4 Tesla magnetic field, for around ten years and for a particle flux of around 10 4 Hz/mm 2 . The CMS detector is described in chapter 2. The operation principle and the problems encountered in the development of MSGC detectors are summarized in chapter 3. The chapter 4 is dedicated to the study of the performances of MSGCs in magnetic fields. In the chapters 5 to 7 the processing of the signal from detectors of this type is described, particularly, the performances of various ways of treat the signal in terms of detection efficiency and counting loads are presented.The chapter 8 presents the results obtained with the prototype obtained at IPNL while the chapter 9 gives the conclusions of the performed works. (author)

  2. Modelling of thermal shock experiments of carbon based materials in JUDITH

    International Nuclear Information System (INIS)

    Ogorodnikova, O.V.; Pestchanyi, S.; Koza, Y.; Linke, J.

    2005-01-01

    The interaction of hot plasma with material in fusion devices can result in material erosion and irreversible damage. Carbon based materials are proposed for ITER divertor armour. To simulate carbon erosion under high heat fluxes, electron beam heating in the JUDITH facility has been used. In this paper, carbon erosion under energetic electron impact is modeled by the 3D thermomechanics code 'PEGASUS-3D'. The code is based on a crack generation induced by thermal stress. The particle emission observed in thermal shock experiments is a result of breaking bonds between grains caused by thermal stress. The comparison of calculations with experimental data from JUDITH shows good agreement for various incident power densities and pulse durations. A realistic mean failure stress has been found. Pre-heating of test specimens results in earlier onset of brittle destruction and enhanced particle loss in agreement with experiments

  3. Modelling of thermal shock experiments of carbon based materials in JUDITH

    Energy Technology Data Exchange (ETDEWEB)

    Ogorodnikova, O.V. [Forschungszentrum Juelich, EURATOM-Association, IWV-2, 52425 Juelich (Germany)]. E-mail: o.ogorodnikova@fz-juelich.de; Pestchanyi, S. [Forschungszentrum Karlsruhe, EURATOM-Associaton, IHM, 76021 Karlsruhe (Germany); Koza, Y. [Forschungszentrum Juelich, EURATOM-Association, IWV-2, 52425 Juelich (Germany); Linke, J. [Forschungszentrum Juelich, EURATOM-Association, IWV-2, 52425 Juelich (Germany)

    2005-03-01

    The interaction of hot plasma with material in fusion devices can result in material erosion and irreversible damage. Carbon based materials are proposed for ITER divertor armour. To simulate carbon erosion under high heat fluxes, electron beam heating in the JUDITH facility has been used. In this paper, carbon erosion under energetic electron impact is modeled by the 3D thermomechanics code 'PEGASUS-3D'. The code is based on a crack generation induced by thermal stress. The particle emission observed in thermal shock experiments is a result of breaking bonds between grains caused by thermal stress. The comparison of calculations with experimental data from JUDITH shows good agreement for various incident power densities and pulse durations. A realistic mean failure stress has been found. Pre-heating of test specimens results in earlier onset of brittle destruction and enhanced particle loss in agreement with experiments.

  4. Modelling of thermal shock experiments of carbon based materials in JUDITH

    Science.gov (United States)

    Ogorodnikova, O. V.; Pestchanyi, S.; Koza, Y.; Linke, J.

    2005-03-01

    The interaction of hot plasma with material in fusion devices can result in material erosion and irreversible damage. Carbon based materials are proposed for ITER divertor armour. To simulate carbon erosion under high heat fluxes, electron beam heating in the JUDITH facility has been used. In this paper, carbon erosion under energetic electron impact is modeled by the 3D thermomechanics code 'PEGASUS-3D'. The code is based on a crack generation induced by thermal stress. The particle emission observed in thermal shock experiments is a result of breaking bonds between grains caused by thermal stress. The comparison of calculations with experimental data from JUDITH shows good agreement for various incident power densities and pulse durations. A realistic mean failure stress has been found. Pre-heating of test specimens results in earlier onset of brittle destruction and enhanced particle loss in agreement with experiments.

  5. International Students from Melbourne Describing Their Cross-Cultural Transitions Experiences: Culture Shock, Social Interaction, and Friendship Development

    Science.gov (United States)

    Belford, Nish

    2017-01-01

    Drawing from a study that explored how international students experience cross-cultural transitions after living and studying in Melbourne for a few years, this paper, in particular, examines the participants' experiences with culture shock, social interaction, and friendship development. The findings include narratives of their personal stories…

  6. UV laser-driven shock-wave experiments at ultrahigh-pressures up to 5 TPa

    Energy Technology Data Exchange (ETDEWEB)

    Cottet, F.; Hallouin, M.; Romain, J.P. (GRECO ILM, Laboratoire d' Enegetique et Detonique, ENSMA, 86 - Poitiers (France)); Fabbro, R.; Faral, B. (GRECO ILM, Laboratoire de Physique des Milieux Ionises, Ecole Polytechnique, 91 - Palaiseau (France))

    1984-11-01

    Laser-driven shock pressures up to 5 TPa at 0.26 ..mu..m wavelenth have been evaluated from measurements of shock velocity through thin metallic foils (Al, Au, Cu) by streak camera records of shock luminosity at the near face of the foil.

  7. UV laser-driven shock-wave experiments at ultrahigh-pressures up to 5 TPa

    International Nuclear Information System (INIS)

    Cottet, F.; Hallouin, M.; Romain, J.P.; Fabbro, R.; Faral, B.

    1984-01-01

    Laser-driven shock pressures up to 5 TPa at 0.26 μm wavelenth have been evaluated from measurements of shock velocity through thin metallic foils (Al, Au, Cu) by streak camera records of shock luminosity at the near face of the foil

  8. Acculturative Experiences Among Indonesian Graduate Students in US Higher Education: Academic Shock, Adjustment, Crisis, and Resolution

    Directory of Open Access Journals (Sweden)

    Amirul Mukminin

    2012-06-01

    Full Text Available The purpose of this qualitative inquiry was to describe and understand the lived experiences of the acculturative process of Indonesian graduate students at an American public research university. The theoretical frameworks of Oberg’s (1960 Culture Shock Model and Berry and his colleagues’ (1987 and Berry’s (2006 Acculturation Stress Model were used to guide this study. Data for this study were collected through a demographic background survey, in-depth interviews, and focus group discussions with Indonesian graduate students. The demographic data were analyzed descriptively. The interviews and focus groups data were analyzed using within-case and cross-case displays and analyses (Miles and Huberman 1994. Five salient themes and sub-themes that emerged were: academic shock, adjustment, crisis, resolution, and what helps/does not help? Implications and strategies for professionals and scholars who work with international students in practice, education, and policy are discussed. In addition, strategies to promote Indonesian graduate students’ academic and social success in graduate programs are included. Suggestions for future research are also discussed.

  9. Laser-driven Mach waves for gigabar-range shock experiments

    Science.gov (United States)

    Swift, Damian; Lazicki, Amy; Coppari, Federica; Saunders, Alison; Nilsen, Joseph

    2017-10-01

    Mach reflection offers possibilities for generating planar, supported shocks at higher pressures than are practical even with laser ablation. We have studied the formation of Mach waves by algebraic solution and hydrocode simulation for drive pressures at much than reported previously, and for realistic equations of state. We predict that Mach reflection continues to occur as the drive pressure increases, and the pressure enhancement increases monotonically with drive pressure even though the ``enhancement spike'' characteristic of low-pressure Mach waves disappears. The growth angle also increases monotonically with pressure, so a higher drive pressure seems always to be an advantage. However, there are conditions where the Mach wave is perturbed by reflections. We have performed trial experiments at the Omega facility, using a laser-heated halfraum to induce a Mach wave in a polystyrene cone. Pulse length and energy limitations meant that the drive was not maintained long enough to fully support the shock, but the results indicated a Mach wave of 25-30 TPa from a drive pressure of 5-6 TPa, consistent with simulations. A similar configuration should be tested at the NIF, and a Z-pinch driven configuration may be possible. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  10. Simulations and Experiments of Dynamic Granular Compaction in Non-ideal Geometries

    Science.gov (United States)

    Homel, Michael; Herbold, Eric; Lind, John; Crum, Ryan; Hurley, Ryan; Akin, Minta; Pagan, Darren; LLNL Team

    2017-06-01

    Accurately describing the dynamic compaction of granular materials is a persistent challenge in computational mechanics. Using a synchrotron x-ray source we have obtained detailed imaging of the evolving compaction front in synthetic olivine powder impacted at 300 - 600 m / s . To facilitate imaging, a non-traditional sample geometry is used, producing multiple load paths within the sample. We demonstrate that (i) commonly used models for porous compaction may produce inaccurate results for complex loading, even if the 1 - D , uniaxial-strain compaction response is reasonable, and (ii) the experimental results can be used along with simulations to determine parameters for sophisticated constitutive models that more accurately describe the strength, softening, bulking, and poroelastic response. Effects of experimental geometry and alternative configurations are discussed. Our understanding of the material response is further enhanced using mesoscale simulations that allow us to relate the mechanisms of grain fracture, contact, and comminution to the macroscale continuum response. Numerical considerations in both continuum and mesoscale simulations are described. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LDRD#16-ERD-010. LLNL-ABS-725113.

  11. Compact Muon Solenoid: largest physics experiment to be held in 2007

    CERN Multimedia

    Atkins, William

    2007-01-01

    "over the last fifteen years about 2'300 engineers and scientists from over 150 scientific institutions in 37 countries around the world have worked together to design and build a gigantic general-purpose particle detector, what is called the Compact Muon Solenoid (CMS)." (1 page)

  12. Performance Evaluation and Analysis of Critical Interface Features of the National Compact Stellarator Experiment (NCSX)

    International Nuclear Information System (INIS)

    Freudenberg, Kevin D.; Litherland, P. Steve; Cole, Michael J.; Williamson, David E.; Goranson, Paul L.; Nelson, Brad E.; Heitzenroeder, P.; Myatt, R.

    2009-01-01

    The (18) modular coils for the National Compact Stellarator Experiment (NCSX) are joined at assembly by interfaces to form a toroidal shell which serves as the structural backbone of the device. There are six each of three coil types (A, B, and C); consequently, there are 4 distinct interface designs (A-A, A-B, B-C, C-C). This paper describes the performance evaluations and analyses used in the development of these critical interfaces. Initial analyses indicated that the baseline interface designs did not provide adequate shear capability along the inner (unbolted) legs between the modular coils and did not adequately address assembly tolerance requirements. Consequently a design effort was undertaken to develop interfaces with adequate shear capability and which would facilitate the achievement of assembly tolerances. Analyses indicated that a friction coefficient of 0.3 is necessary for 'no-slip' joints with a preload value of ∼320 kN in the outboard regions. Two types of compatible segmented friction shims were developed to meet the friction requirement. One type uses alumina coated stainless steel shims and the other uses G-10/ stainless steel/ G-10 'sandwich shims.' Analyses indicated that the time constant requirements for induced currents in the shell could still be achieved with welds along all the inner (unbolted) legs except at the C-C interface. Consequently, welded interfaces utilizing alternating MIG fillet welds on each end of shims between coil castings were developed to react the shear loads. This configuration minimizes distortion since it avoids direct weld shrinkage stress across the interfaces. Analyses indicates that a 12.7 mm fillet weld has adequate shear capability, with average stress through the welds of 90-125 MPa, compared to a static limit of 217 MPa. Custom sized compression pucks located in the middle of the welded shims react the compressive loads and have average stresses less than 137 MPa. Fatigue acceptability of the welded

  13. Spherical shock-ignition experiments with the 40 + 20-beam configuration on OMEGA

    Energy Technology Data Exchange (ETDEWEB)

    Theobald, W.; Anderson, K. S.; Delettrez, J. A.; Glebov, V. Yu.; Gotchev, O. V.; Hohenberger, M.; Hu, S. X.; Marshall, F. J.; Sangster, T. C.; Seka, W.; Stoeckl, C.; Yaakobi, B. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Nora, R.; Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Department of Mechanical Engineering and Physics at the University of Rochester, Rochester, New York 14623 (United States); Lafon, M. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); University of Bordeaux, CEA, CNRS, CELIA (Centre Lasers Intenses et Applications), F-33400 Talence (France); Casner, A. [CEA, DAM, DIF, F-91297 Arpajon (France); Ribeyre, X.; Schurtz, G. [University of Bordeaux, CEA, CNRS, CELIA (Centre Lasers Intenses et Applications), F-33400 Talence (France); Frenje, J. A. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); and others

    2012-10-15

    Spherical shock-ignition experiments on OMEGA used a novel beam configuration that separates low-intensity compression beams and high-intensity spike beams. Significant improvements in the performance of plastic-shell, D{sub 2} implosions were observed with repointed beams. The analysis of the coupling of the high-intensity spike beam energy into the imploding capsule indicates that absorbed hot-electron energy contributes to the coupling. The backscattering of laser energy was measured to reach up to 36% at single-beam intensities of {approx}8 Multiplication-Sign 10{sup 15} W/cm{sup 2}. Hard x-ray measurements revealed a relatively low hot-electron temperature of {approx}30 keV independent of intensity and timing. At the highest intensity, stimulated Brillouin scattering occurs near and above the quarter-critical density and the two-plasmon-decay instability is suppressed.

  14. Analysis of crack behavior in the JRC Ispra pressurized thermal shock experiment

    International Nuclear Information System (INIS)

    Jovanovic, A.; Lucia, A.C.

    1990-01-01

    The analytical work performed in the framework of the Pressurized Thermal Shock (PTS) experimental research at the JRC Ispra, Italy, is described in the paper. In particular, the development of the FRAP preprocessor and development and implementation of a methodology for analysis of local non-stationary heat transfer coefficients during a PTS, have been tackled. FRAP is used as a front-end for the finite element code ABAQUS, for the heat transfer, stress and fracture mechanics analyses. The ABAQUS results are used further on, for the probabilistic fatigue crack analysis performed by the JRC Ispra code COVASTOL. Only the preliminary results of application of FRAP, ABAQUS and COVASTOL codes in the experiment are given in this paper, in order to illustrate the applied analytical procedure. (orig.)

  15. Pressure vessel fracture studies pertaining to a PWR LOCA-ECC thermal shock: experiments TSE-1 and TSE-2

    International Nuclear Information System (INIS)

    Cheverton, R.D.

    1976-09-01

    The LOCA-ECC Thermal Shock Program was established to investigate the potential for flaw propagation in pressurized-water reactor (PWR) vessels during injection of emergency core coolant following a loss-of-coolant accident. Studies thus far have included fracture mechanics analyses of typical PWRs, the design and construction of a thermal shock test facility, determination of material properties for test specimens, and two thermal shock experiments with 0.53-m-OD (21-in.) by 0.15-m-wall (6-in.) cylindrical test specimens. The PWR calculations indicated that under some circumstances crack propagation could be expected and that experiments should be conducted for cracks that would have the potential for propagation at least halfway through the wall

  16. CHESS upgrade with compact undulator magnets: Operating experience and first results

    Energy Technology Data Exchange (ETDEWEB)

    Temnykh, A., E-mail: abt6@cornell.edu; Dale, D.; Fontes, E.; Lyndaker, A.; Li, Y.; Ruff, J.; Revesz, P.; Woll, A. [Cornell High Energy Synchrotron Source (United States)

    2016-07-27

    In November 2014 two in-air 1.5 m CHESS Compact Undulator (CCU) magnets built by KYMA S.R.l. were installed in Cornell Electron Storage Ring (CESR) in canted arrangement and after few days of commissioning their regular operation started. CCU magnets are compact, lightweight and cost efficient devices. They have very stable magnetic field integrals independent of deflection parameter value. This feature greatly simplifies the storage ring operation. The CCU concept was developed at Cornell in 2011 and the first 1 m in-vacuum CCU magnet was beam-tested in 2012. The article presents CCU concept and some details of the design. It describes also the layout of CCUs installation in CESR, their performance and characteristics. The current status of operation and future plans are discussed as well. Presently, at CHESS two CCU magnets provide radiation for 5 out of 11 experimental stations.

  17. CHESS upgrade with compact undulator magnets: Operating experience and first results

    International Nuclear Information System (INIS)

    Temnykh, A.; Dale, D.; Fontes, E.; Lyndaker, A.; Li, Y.; Ruff, J.; Revesz, P.; Woll, A.

    2016-01-01

    In November 2014 two in-air 1.5 m CHESS Compact Undulator (CCU) magnets built by KYMA S.R.l. were installed in Cornell Electron Storage Ring (CESR) in canted arrangement and after few days of commissioning their regular operation started. CCU magnets are compact, lightweight and cost efficient devices. They have very stable magnetic field integrals independent of deflection parameter value. This feature greatly simplifies the storage ring operation. The CCU concept was developed at Cornell in 2011 and the first 1 m in-vacuum CCU magnet was beam-tested in 2012. The article presents CCU concept and some details of the design. It describes also the layout of CCUs installation in CESR, their performance and characteristics. The current status of operation and future plans are discussed as well. Presently, at CHESS two CCU magnets provide radiation for 5 out of 11 experimental stations.

  18. Double shock experiments and reactive flow modeling on LX-17 to understand the reacted equation of state

    International Nuclear Information System (INIS)

    Vandersall, Kevin S; Garcia, Frank; Fried, Laurence E; Tarver, Craig M

    2014-01-01

    Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments.

  19. Shock wave equation of state of powder material

    OpenAIRE

    Dijken, D.K.; Hosson, J.Th.M. De

    1994-01-01

    A model is proposed to predict the following quantities for powder materials compacted by shock waves: the pressure, the specific volume, the internal energy behind the shock wave, and the shock-wave velocity U-s. They are calculated as a function of flyerplate velocity u(p) and initial powder specific volume V-00. The model is tested on Cu, Al2024, and Fe. Calculated U-s vs u(p) curves agree well with experiments provided V-00 is smaller than about two times the solid specific volume. The mo...

  20. Development of a new compact intraoperative magnetic resonance imaging system: concept and initial experience.

    Science.gov (United States)

    Morita, Akio; Sameshima, Tetsuro; Sora, Shigeo; Kimura, Toshikazu; Nishimura, Kengo; Itoh, Hirotaka; Shibahashi, Keita; Shono, Naoyuki; Machida, Toru; Hara, Naoko; Mikami, Nozomi; Harihara, Yasushi; Kawate, Ryoichi; Ochiai, Chikayuki; Wang, Weimin; Oguro, Toshiki

    2014-06-01

    Magnetic resonance imaging (MRI) during surgery has been shown to improve surgical outcomes, but the current intraoperative MRI systems are too large to install in standard operating suites. Although 1 compact system is available, its imaging quality is not ideal. We developed a new compact intraoperative MRI system and evaluated its use for safety and efficacy. This new system has a magnetic gantry: a permanent magnet of 0.23 T and an interpolar distance of 32 cm. The gantry system weighs 2.8 tons and the 5-G line is within the circle of 2.6 m. We created a new field-of-view head coil and a canopy-style radiofrequency shield for this system. A clinical trial was initiated, and the system has been used in 44 patients. This system is significantly smaller than previous intraoperative MRI systems. High-quality T2 images could discriminate tumor from normal brain tissue and identify anatomic landmarks for accurate surgery. The average imaging time was 45.5 minutes, and no clinical complications or MRI system failures occurred. Floating organisms or particles were minimal (1/200 L maximum). This intraoperative, compact, low-magnetic-field MRI system can be installed in standard operating suites to provide relatively high-quality images without sacrificing safety. We believe that such a system facilitates the introduction of the intraoperative MRI.

  1. Multiscale modeling of beryllium: quantum mechanics and laser-driven shock experiments using novel diagnostics

    International Nuclear Information System (INIS)

    Swift, D.C.; Paisley, Dennis L.; Kyrala, George A.; Hauer, Allan

    2002-01-01

    Ab initio quantum mechanics was used to construct a thermodynamically complete and rigorous equation of state for beryllium in the hexagonal and body-centred cubic structures, and to predict elastic constants as a function of compression. The equation of state agreed well with Hugoniot data and previously-published equations of state, but the temperatures were significantly different. The hexagonal/bcc phase boundary agreed reasonably well with published data, suggesting that the temperatures in our new equation of state were accurate. Shock waves were induced in single crystals and polycrystalline foils of beryllium, by direct illumination using the TRIDENT laser at Los Alamos. The velocity history at the surface of the sample was measured using a line-imaging VISAR, and transient X-ray diffraction (TXD) records were obtained with a plasma backlighter and X-ray streak cameras. The VISAR records exhibited elastic precursors, plastic waves, phase changes and spall. Dual TXD records were taken, in Bragg and Laue orientations. The Bragg lines moved in response to compression in the uniaxial direction. Because direct laser drive was used, the results had to be interpreted with the aid of radiation hydrodynamics simulations to predict the loading history for each laser pulse. In the experiments where there was evidence of polymorphism in the VISAR record, additional lines appeared in the Bragg and Laue records. The corresponding pressures were consistent with the phase boundary predicted by the quantum mechanical equation of state for beryllium. A model of the response of a single crystal of beryllium to shock loading is being developed using these new theoretical and experimental results. This model will be used in meso-scale studies of the response of the microstructure, allowing us to develop a more accurate representation of the behaviour of polycrystalline beryllium.

  2. Compact field programmable gate array-based pulse-sequencer and radio-frequency generator for experiments with trapped atoms

    Energy Technology Data Exchange (ETDEWEB)

    Pruttivarasin, Thaned, E-mail: thaned.pruttivarasin@riken.jp [Quantum Metrology Laboratory, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Katori, Hidetoshi [Quantum Metrology Laboratory, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Innovative Space-Time Project, ERATO, JST, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-11-15

    We present a compact field-programmable gate array (FPGA) based pulse sequencer and radio-frequency (RF) generator suitable for experiments with cold trapped ions and atoms. The unit is capable of outputting a pulse sequence with at least 32 transistor-transistor logic (TTL) channels with a timing resolution of 40 ns and contains a built-in 100 MHz frequency counter for counting electrical pulses from a photo-multiplier tube. There are 16 independent direct-digital-synthesizers RF sources with fast (rise-time of ∼60 ns) amplitude switching and sub-mHz frequency tuning from 0 to 800 MHz.

  3. Fracture-mechanics data deduced from thermal-shock and related experiments with LWR pressure-vessel material

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Canonico, D.A.; Iskander, S.K.; Bolt, S.E.; Holz, P.P.; Nanstad, R.K.; Stelzman, W.J.

    1982-01-01

    Pressurized water reactors (PWRs) are susceptible to certain types of hypothetical accidents that can subject the reactor pressure vessel to severe thermal shock, that is, a rapid cooling of the inner surface of the vessel wall. The thermal-shock loading, coupled with the radiation-induced reduction in the material fracture toughness, introduces the possibility of propagation of preexistent flaws and what at one time were regarded as somewhat unique fracture-oriented conditions. Several postulated reactor accidents have been analyzed to discover flaw behavior trends; seven intermediate-scale thermal-shock experiments with steel cylinders have been conducted; and corresponding materials characterization studies have been performed. Flaw behavior trends and related fracture-mechanics data deduced from these studies are discussed

  4. A compact led lidar system fitted for a mars rover - design and ground experiment

    Science.gov (United States)

    Ong, Prane Mariel B.; Shiina, Tatsuo; Manago, Naohiro; Kuze, Hiroaki; Senshu, Hiroki; Otobe, Naohito; Hashimoto, George; Kawabata, Yasuhiro

    2018-04-01

    A compact LED lidar was constructed and fieldtested with the aim to observe the Mars' dust devils. To be able to fit it on the Mars rover, a specialized Cassegrain telescope was designed to be within a 10 cm-cube, with a field of view of 3mrad. The transmitter has 385 nm LED light source with 3 cmϕ opening, 70mrad divergence, 0.75W (7.5nJ/10ns) pulse power, and 500 kHz repetition frequency. The configuration of the optical system is biaxial to easily configure the overlap between their optical axes.

  5. A compact led lidar system fitted for a mars rover – design and ground experiment

    Directory of Open Access Journals (Sweden)

    Ong Prane Mariel B.

    2018-01-01

    Full Text Available A compact LED lidar was constructed and fieldtested with the aim to observe the Mars’ dust devils. To be able to fit it on the Mars rover, a specialized Cassegrain telescope was designed to be within a 10 cm-cube, with a field of view of 3mrad. The transmitter has 385 nm LED light source with 3 cmϕ opening, 70mrad divergence, 0.75W (7.5nJ/10ns pulse power, and 500 kHz repetition frequency. The configuration of the optical system is biaxial to easily configure the overlap between their optical axes.

  6. Thermodynamically Based Equation of State for Shock Wave Studies : Application to the Design of Experiments on Tin

    International Nuclear Information System (INIS)

    Buy, Francois; Voltz, Christophe; Llorca, Fabrice

    2006-01-01

    This work is devoted to the evaluation of complex behavior of metals under shock wave loading. It presents a methodology for the design of specific experiments performed for validation of models and the evaluation of a multiphase equation of state for tin. This material has been selected because of the numerous works completed during the past years on its equation of state. We focus on the solid diagram which presents two solid phases. A thermodynamically based equation of state is developed which gives the opportunity to search for singularities which could be activated under particular shock wave loading. In the temperature -- pressure diagram, the superimposed Hugoniot and release paths make apparent a double shock, release shock configurations. We propose the design and the VISAR results of a calibrated shock -- reshock test for investigating the validity and the efficiency of the model for predicting the thermodynamical state of tin (phases mixing, temperature...). Comparison between numerical and experimental data shows the good accuracy of the results given by the EOS

  7. ComVisMD - compact visualization of multidimensional data: experimenting with cricket players data

    Science.gov (United States)

    Dandin, Shridhar B.; Ducassé, Mireille

    2018-03-01

    Database information is multidimensional and often displayed in tabular format (row/column display). Presented in aggregated form, multidimensional data can be used to analyze the records or objects. Online Analytical database Processing (OLAP) proposes mechanisms to display multidimensional data in aggregated forms. A choropleth map is a thematic map in which areas are colored in proportion to the measurement of a statistical variable being displayed, such as population density. They are used mostly for compact graphical representation of geographical information. We propose a system, ComVisMD inspired by choropleth map and the OLAP cube to visualize multidimensional data in a compact way. ComVisMD displays multidimensional data like OLAP Cube, where we are mapping an attribute a (first dimension, e.g. year started playing cricket) in vertical direction, object coloring based on b (second dimension, e.g. batting average), mapping varying-size circles based on attribute c (third dimension, e.g. highest score), mapping numbers based on attribute d (fourth dimension, e.g. matches played). We illustrate our approach on cricket players data, namely on two tables Country and Player. They have a large number of rows and columns: 246 rows and 17 columns for players of one country. ComVisMD’s visualization reduces the size of the tabular display by a factor of about 4, allowing users to grasp more information at a time than the bare table display.

  8. Investigating pyroclast ejection dynamics using shock-tube experiments: temperature, grain size and vent geometry effects.

    Science.gov (United States)

    Cigala, V.; Kueppers, U.; Dingwell, D. B.

    2015-12-01

    Explosive volcanic eruptions eject large quantities of gas and particles into the atmosphere. The portion directly above the vent commonly shows characteristics of underexpanded jets. Understanding the factors that influence the initial pyroclast ejection dynamics is necessary in order to better assess the resulting near- and far-field hazards. Field observations are often insufficient for the characterization of volcanic explosions due to lack of safe access to such environments. Fortunately, their dynamics can be simulated in the laboratory where experiments are performed under controlled conditions. We ejected loose natural particles from a shock-tube while controlling temperature (25˚ and 500˚C), overpressure (15MPa), starting grain size distribution (1-2 mm, 0.5-1 mm and 0.125-0.250 mm), sample-to-vent distance and vent geometry. For each explosion we quantified the velocity of individual particles, the jet spreading angle and the production of fines. Further, we varied the setup to allow for different sample-to-gas ratios and deployed four different vent geometries: 1) cylindrical, 2) funnel with a flaring of 30˚, 3) funnel with a flaring of 15˚ and 4) nozzle. The results showed maximum particle velocities up to 296 m/s, gas spreading angles varying from 21˚ to 37˚ and particle spreading angles from 3˚ to 40˚. Moreover we observed dynamically evolving ejection characteristics and variations in the production of fines during the course of individual experiments. Our experiments mechanistically mimic the process of pyroclast ejection. Thus the capability for constraining the effects of input parameters (fragmentation conditions) and conduit/vent geometry on ballistic pyroclastic plumes has been clearly established. These data obtained in the presence of well-documented conduit and vent conditions, should greatly enhance our ability to numerically model explosive ejecta in nature.

  9. Shock tube experiments on nitromethane and Promotion of chemical reactions by non-thermal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Seljeskog, Morten

    2002-06-01

    This dissertation was undertaken to study two different subjects both related to molecular decomposition by applying a shock tube and non-thermal plasma to decompose selected hydrocarbons. The first approach to molecular decomposition concerned thermal decomposition and oxidation of highly diluted nitromethane (NM) in a shock tube. Reflected shock tube experiments on NM decomposition, using mixtures of 0.2 to 1.5 vol% NM in nitrogen or argon were performed over the temperature range 850-1550 K and pressure range 190-900 kPa, with 46 experiments diluted in nitrogen and 44 diluted in argon. By residual error analysis of the measured decomposition profiles it was found that NM decomposition (CH{sub 3}NO{sub 2} + M {yields} CH{sub 3} + NO{sub 2} + M, where M = N{sub 2} /Ar) corresponds well to a law of first order. Arrhenius expressions corresponding to NM diluted either in N{sub 2} or in Ar were found as k{sub N2} = 10{sup 17.011} * exp(- 182.6 kJ/mole / R*T) and k{sub Ar} = 10{sup 17.574}*exp(-207 kJ/mole / R*T ) , respectively. A new reaction mechanism was then proposed, based on new experimental data for NM decomposition both in Ar and N{sub 2} and on three previously developed mechanisms. The new mechanism predicts well the decomposition of NM diluted in both N{sub 2} and Ar within the pressure and temperature range covered by the experiments. In parallel to, and following the decomposition experiments, oxidative experiments on the ignition delay times of NM/O{sub 2}/Ar mixtures were investigated over high temperature and low to high pressure ranges. These experiments were carried out with eight different mixtures of gaseous NM and oxygen diluted in argon, with pressures ranging between 44.3-600 kPa, and temperatures ranging between 842-1378 K. The oxidation experiments were divided into different categories according to the type of decomposition signals achieved. For signals with and without emission, the apparent quasi

  10. Ultrafast Fiber Bragg Grating Interrogation for Sensing in Detonation and Shock Wave Experiments.

    Science.gov (United States)

    Rodriguez, George; Gilbertson, Steve M

    2017-01-27

    Chirped fiber Bragg grating (CFBG) sensors coupled to high speed interrogation systems are described as robust diagnostic approaches to monitoring shock wave and detonation front propagation tracking events for use in high energy density shock physics applications. Taking advantage of the linear distributed spatial encoding of the spectral band in single-mode CFBGs, embedded fiber systems and associated photonic interrogation methodologies are shown as an effective approach to sensing shock and detonation-driven loading processes along the CFBG length. Two approaches, one that detects spectral changes in the integrated spectrum of the CFBG and another coherent pulse interrogation approach that fully resolves its spectral response, shows that 100-MHz-1-GHz interrogation rates are possible with spatial resolution along the CFBG in the 50 µm to sub-millimeter range depending on the combination of CFBG parameters (i.e., length, chirp rate, spectrum) and interrogator design specifics. Results from several dynamic tests are used to demonstrate the performance of these high speed systems for shock and detonation propagation tracking under strong and weak shock pressure loading: (1) linear detonation front tracking in the plastic bonded explosive (PBX) PBX-9501; (2) tracking of radial decaying shock with crossover to non-destructive CFBG response; (3) shock wave tracking along an aluminum cylinder wall under weak loading accompanied by dynamic strain effects in the CFBG sensor.

  11. Critical experiments in support of the CNPS [Compact Nuclear Power Source] program

    International Nuclear Information System (INIS)

    Hansen, G.E.; Audas, J.H.; Martin, E.R.; Pederson, R.A.; Spriggs, G.D.; White, R.H.

    1988-01-01

    Zero-power static and kinetic measurements have been made on a mock-up of the Compact Nuclear Power Source (CNPS), a graphite moderated, graphite reflected, U(19.9% 235 U) fueled reactor design. Critical configurations were tracked from a first clean configuration (184 most central fuel channels filled and all control rod and heat pipe channels empty) to a fully loaded configuration (all 492 fuel channels filled, core-length stainless steel pipe in the twelve heat-pipe channels, and approximately half-core-length boron carbide in the outer 4 control rod channels. Reactor physics data such as material worths and neutron lifetime are presented only for the clean and fully loaded configurations

  12. CFD Validation Experiment of a Mach 2.5 Axisymmetric Shock-Wave/Boundary-Layer Interaction

    Science.gov (United States)

    Davis, David O.

    2015-01-01

    Experimental investigations of specific flow phenomena, e.g., Shock Wave Boundary-Layer Interactions (SWBLI), provide great insight to the flow behavior but often lack the necessary details to be useful as CFD validation experiments. Reasons include: 1.Undefined boundary conditions Inconsistent results 2.Undocumented 3D effects (CL only measurements) 3.Lack of uncertainty analysis While there are a number of good subsonic experimental investigations that are sufficiently documented to be considered test cases for CFD and turbulence model validation, the number of supersonic and hypersonic cases is much less. This was highlighted by Settles and Dodsons [1] comprehensive review of available supersonic and hypersonic experimental studies. In all, several hundred studies were considered for their database.Of these, over a hundred were subjected to rigorous acceptance criteria. Based on their criteria, only 19 (12 supersonic, 7 hypersonic) were considered of sufficient quality to be used for validation purposes. Aeschliman and Oberkampf [2] recognized the need to develop a specific methodology for experimental studies intended specifically for validation purposes.

  13. Extracorporeal shock wave lithotripsy for renal calculi, experience of first 100 cases at Jinnah Hospital, Lahore

    International Nuclear Information System (INIS)

    Nawaz, A.; Hussain, S.; Tahir, M.M.; Iqbal, N.

    1999-01-01

    Extracorporeal shock wave lithotripsy (ESWL), where available, has become the preferred treatment modality for majority of renal calculi. Nevertheless because of low morbidity and strong patient endorsement there is a natural tendency of over using it. We report the experience of first 100 patients of renal calculi treated at Lithotripsy Center, Jinnah Hospital, Lahore between November 1993 and October 1995.. All patients were treated on an out patients basis. In this prospective study patients were divided into three groups depending upon the initial stone size (Group 1 2.1 to 3 cm). Twenty-eight patients were lost to follow-up. Analysis of data revealed a success rate of 89.5%, 65.8% and 33.3% in Group-I, II and III respectively at the end of 3 months follow-up. Morbidity was directly procedures to stone burden, while success was inversely related to stone burden. Complications requiring auxiliary procedures were seen in none of the patients of Group-I while in 17.1% and 25% of the patients of Group-II and III respectively. Failure of the procedure demanding for an open intervention was seen in none of the patients of Group II and III respectively. We concluded that selection of patients is key to successful management of the renal calculi with ESWL. (author)

  14. Polarized radio outbursts in BL Lacertae. I. Polarized emission from a compact jet. II. The flux and polarization of a piston-driven shock

    International Nuclear Information System (INIS)

    Aller, H.D.; Aller, M.F.; Hughes, P.A.

    1985-01-01

    A second highly polarized burst in BL Lacertae observed in 1983 which has very similar properties to the earlier burst in 1981-82 is described, and it is shown that in both bursts the electric vector of the polarized emission is nearly parallel to the observed extended structure. A weak shock, moving relativistically close to the line of sight, appears to be a very effective means of producing the observed behavior. A simple model is developed to represent the outbursts as due to a piston-driven shock which exhibits polarized emission due to compression of the otherwise random magnetic field of a collimated flow. It is shown that the general features of total flux, polarized flux, and polarization position angle as a function of frequency and time can be understood in terms of such a model. 34 references

  15. Experiments on ion-acoustic shock waves in a dusty plasma

    International Nuclear Information System (INIS)

    Nakamura, Y.

    2002-01-01

    Dust ion-acoustic shock waves have been investigated experimentally in a homogeneous unmagnetized dusty double-plasma device. An initial compressional wave with a ramp shape steepens to form oscillations at the leading part due to dispersion. The oscillation develops to a train of solitons when the plasma contains no dust grain. The wave becomes an oscillatory shock wave when the dust is mixed in the plasma and the density of the dust grains is smaller than a critical value. When the dust density is larger than the critical value, only steepening is observed at the leading part of the wave and a monotonic shock structure is observed. The velocity and width of the shock waves are measured and compared with results of numerical integrations of the modified Korteweg-de Vries-Burgers equation

  16. Optimal Bayesian experimental design for priors of compact support with application to shock-tube experiments for combustion kinetics

    KAUST Repository

    Bisetti, Fabrizio; Kim, Daesang; Knio, Omar; Long, Quan; Tempone, Raul

    2016-01-01

    to account for the bounded domain of the uniform prior pdf of the parameters. The underlying Gaussian distribution is obtained in the spirit of the Laplace method, more precisely, the mode is chosen as the maximum a posteriori (MAP) estimate

  17. Shock compression of glow discharge polymer (GDP): density functional theory (DFT) simulations and experiments on Sandia's Z machine

    Science.gov (United States)

    Cochrane, Kyle R.; Ao, T.; Lemke, R. W.; Hamel, S.; Schoff, M. E.; Blue, B. E.; Herrmann, M. C.; Mattsson, T. R.

    2014-03-01

    Glow discharge polymer (GDP) is used extensively as capsule/ablation material in inertial confinement fusion (ICF) capsules. Accurate knowledge of the equation of state (EOS) under shock and release is particularly important for high-fidelity design, analysis, and optimization of ICF experiments since the capsule material is subject to several converging shocks as well as release towards the cryogenic fuel. We performed Density Functional Theory (DFT) based quantum molecular dynamics (QMD) simulations, to gain knowledge of the behavior of GDP - for example regarding the role of chemical dissociation during shock compression, we find that the dissociation regime along the Hugoniot extends from 50 GPa to 250 GPa. The shock pressures calculated from DFT are compared experimental data taken at Sandia's Z-machine. The GDP samples were grown in a planar geometry to improve the sample quality and maintained in a nitrogen atmosphere following manufacturing, thus allowing for a direct comparison to the DFT/QMD simulations. Sandia National Laboratories is a multi program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under contract DE-AC04-94AL85000.

  18. Compact toroids generated by a magnetized coaxial source in the CTX experiment

    International Nuclear Information System (INIS)

    Sherwood, A.R.; Henins, I.; Hoida, H.W.; Jarboe, T.R.; McKenna, K.F.; Linford, R.K.; Marshall, J.; Platts, D.A.

    1981-01-01

    Compact toroids containing both toroidal and poloidal magnetic field (Spheromak-type) have been generated in CTX using a magnetized coaxial plasma gun. These CTs tear loose from the gun by magnetic field line reconnection, and they are trapped in flux conservers having various geometries. In a straight cylindrical flux conserver the CTs are observed to be unstable to a gross tilting mode. Stability to the tilting mode has been demonstrated in flux conservers having an oblate trapping region; however, the geometry of the entrance region leading to the trapping volume can also have important effects. Lifetimes of about 150 μs for the CTs are typically observed. Interferometric measurements give a value of about 2 x 10 14 cm -3 for the initial plasma density. The plasma temperature measured at a single spot near the minor magnetic axis decreases to around 10 eV by the time the magnetic reconnection is complete. Spectrographic measurements and pressure probe results are in agreement with this temperature. A snipper coil has been installed to induce the CT to tear loose from the gun sooner. The use of this coil is observed to speed up the magnetic field reconnection process by about a factor of 2

  19. Compact toroids generated by a magnetized coaxial source in the CTX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, A.R.; Henins, I.; Hoida, H.W.; Jarboe, T.R.; McKenna, K.F.; Linford, R.K.; Marshall, J.; Platts, D.A.

    1981-01-01

    Compact toroids containing both toroidal and poloidal magnetic field (Spheromak-type) have been generated in CTX using a magnetized coaxial plasma gun. These CTs tear loose from the gun by magnetic field line reconnection, and they are trapped in flux conservers having various geometries. In a straight cylindrical flux conserver the CTs are observed to be unstable to a gross tilting mode. Stability to the tilting mode has been demonstrated in flux conservers having an oblate trapping region; however, the geometry of the entrance region leading to the trapping volume can also have important effects. Lifetimes of about 150 ..mu..s for the CTs are typically observed. Interferometric measurements give a value of about 2 x 10/sup 14/ cm/sup -3/ for the initial plasma density. The plasma temperature measured at a single spot near the minor magnetic axis decreases to around 10 eV by the time the magnetic reconnection is complete. Spectrographic measurements and pressure probe results are in agreement with this temperature. A snipper coil has been installed to induce the CT to tear loose from the gun sooner. The use of this coil is observed to speed up the magnetic field reconnection process by about a factor of 2.

  20. Comparative study of the electron density profiles in the compact torus plasma merging experiments

    International Nuclear Information System (INIS)

    Hayashiya, Hitoshi; Asaka, Takeo; Katsurai, Makoto

    2003-01-01

    Following two previous papers on the comparative studies of the electron density distributions for a single compact torus (CT) and a spherical tokamak (ST), and for the a single ST and a merged ST, a comparative study on the dynamics of the electron density profile and after the CT and ST plasma merging process was performed. The sharpness of the peak in the electron density profile around the mid-plane just after the merging of CT with a low safety factor (q value) such as RFP or spheromak is found to be related to the speed of the magnetic axis during the plasma merging process. It is also found that the electron density gradient near the plasma edge in a high q ST is larger than that of a low q CT. High q ST is found to be provided with the magnetic structure which is able to sustain a large thermal pressure by a strong j x B force. Despite these differences in the electron density profile between CT and ST during merging, the confinement characteristics evaluated from the number of electrons confined within the magnetic separatrix after the completion of the merging is almost similar between in the merging CT and in the merging ST. For all configurations, the electron density profiles after the completion of the merging are analogous to those of the corresponding single configuration produced without the merging process. (author)

  1. Simulations of Low-q Disruptions in the Compact Toroidal Hybrid Experiment

    Science.gov (United States)

    Howell, E. C.; Hanson, J. D.; Ennis, D. A.; Hartwell, G. J.; Maurer, D. A.

    2017-10-01

    Resistive MHD simulations of low-q disruptions in the Compact Toroidal Hybrid Device (CTH) are performed using the NIMROD code. CTH is a current-carrying stellarator used to study the effects of 3D shaping on MHD stability. Experimentally, it is observed that the application of 3D vacuum fields allows CTH to operate with edge safety factor less than 2.0. However, these low-q discharges often disrupt after peak current if the applied 3D fields are too weak. Nonlinear simulations are initialized using model VMEC equilibria representative of low-q discharges with weak vacuum transform. Initially a series of symmetry preserving island chains are excited at the q=6/5, 7/5, 8/5, and 9/5 rational surfaces. These island chains act as transport barriers preventing stochastic magnetic fields in the edge from penetrating into the core. As the simulation progresses, predominately m/n=3/2 and 4/3 instabilities are destabilized. As these instabilities grow to large amplitude they destroy the symmetry preserving islands leading to large regions of stochastic fields. A current spike and loss of core thermal confinement occurs when the innermost island chain (6/5) is destroyed. Work Supported by US-DOE Grant #DE-FG02-03ER54692.

  2. Analysis and experiments of a novel and compact 3-DOF precision positioning platform

    International Nuclear Information System (INIS)

    Huang, Hu; Zhao, Hongwei; Fan, Zunqiang; Zhang, Hui; Ma, Zhichao; Yang, Zhaojun

    2013-01-01

    A novel 3-DOF precision positioning platform with dimensions of 48 mm X 50 mm X 35 mm was designed by integrating piezo actuators and flexure hinges. The platform has a compact structure but it can do high precision positioning in three axes. The dynamic model of the platform in a single direction was established. Stiffness of the flexure hinges and modal characteristics of the flexure hinge mechanism were analyzed by the finite element method. Output displacements of the platform along three axes were forecasted via stiffness analysis. Output performance of the platform in x and y axes with open-loop control as well as the z-axis with closed-loop control was tested and discussed. The preliminary application of the platform in the field of nanoindentation indicates that the designed platform works well during nanoindentation tests, and the closed-loop control ensures the linear displacement output. With suitable control, the platform has the potential to realize different positioning functions under various working conditions.

  3. Compact and lightweight support platform with electromagnetic disturbance elimination for interferometer on reversed field pinch Keda Torus eXperiment

    Science.gov (United States)

    Mao, Wenzhe; Yuan, Peng; Zheng, Jian; Ding, Weixing; Li, Hong; Lan, Tao; Liu, Adi; Liu, Wandong; Xie, Jinlin

    2016-11-01

    A compact and lightweight support platform has been used as a holder for the interferometer system on the Keda Torus eXperiment (KTX), which is a reversed field pinch device. The vibration caused by the interaction between the time-varying magnetic field and the induced current driven in the metal optical components has been measured and, following comparison with the mechanical vibration of the KTX device and the refraction effect of the ambient turbulent air flow, has been identified as the primary vibration source in this case. To eliminate this electromagnetic disturbance, nonmetallic epoxy resin has been selected as the material for the support platform and the commercially available metal optical mounts are replaced. Following these optimization steps and mechanical reinforcements, the stability of the interferometer platform has improved significantly. The phase shift caused by the vibration has been reduced to the level of background noise.

  4. Heat transfer in large compacts of SYNROC powder

    International Nuclear Information System (INIS)

    Buykx, W.J.

    1984-01-01

    The parameters determining the time required to reach temperature uniformity in a shock heated cylindrical compact of SYNROC powder are identified as the dimensions of the compact and the thermal diffusivity of the material. The effect of shape and size of the compact are discussed, and an experimental study of the factors influencing the thermal diffusivity of compacted SYNROC powder is described

  5. Electromagnetically driven radiative shocks and their measurements

    International Nuclear Information System (INIS)

    Kondo, K.; Watanabe, M.; Nakajima, M.; Kawamura, T.; Horioka, K.

    2005-01-01

    Experimental results on a generation of strong shocks in a compact pulse power device are reported. The characteristics of strong shocks are different from hydrodynamical shocks' because they depend on not only collisions but radiation processes. Radiative shocks are relevant to high energy density phenomena such as the explosions of supernovae. When initial pressure is lower than about 50 mtorr, an interesting structure is confirmed at the shock front, which might indicate a phenomenon proceeded by the radiative process. (author)

  6. Restrained shrinkage experiments on coated particle fuel compacts in the temperature range 600-1200 deg C

    International Nuclear Information System (INIS)

    Blackstone, R.; Veringa, H.J.; Loelgen, R.

    1976-05-01

    Information on irradiation induced creep in reactor graphite and in fuel compact material is an essential ingredient in the design of any reactor core layout, because the creep plasticity of these materials diminishes the stresses which are built up in the fuel element during reactor operation. The restrained shrinkage method in which the shrinkage of a dumbbell shaped creep specimen is restrained by a graphite material which shows less irradiation shrinkage, offers a good possibility of performing a large series of tensile creep experiments in a limited irradiation volume. The irradiations, evaluations and the results of a series of restrained shrinkage experiments in which six different materials were tested, of which five were dummy coated particle compacts and one pure matrix material are described and discussed. These materials were irradiated in the High Flux Reactor of the Euratom Joint Research Centre in Petten/Netherlands. The irradiations were performed in three successive capsules at irradiation temperatures of 600 deg C, 900 deg C, 1050 deg C and 1200 deg C up to a neutron fluence of maximum 3x10 21 n.cm 2 (DNE). The post-irradiation examinations yielded plastic strains up to 2,3%, and values for the radiation creep coefficient were calculated, ranging from 4 to 8.10 -12 at 600 deg C and 8 to 30.10 -12 at 1200 deg C always given per dyn.cm -2 tensile stresses and per 10 20 n.cm -2 fluence units. Generally it was found that the creep behavior of these materials and the temperature dependence of the creep process could be compared with those for normal reactor graphites

  7. Visualization environment for reviewing and experimenting with compaction equipment trajectories in context

    NARCIS (Netherlands)

    Vasenev, Alexandr; Hartmann, Timo; Miller, Seirgei Rosario; Doree, Andries G.

    Visualization Environments (VEs) can assist construction professionals in studying intricate interrelations between construction equipment trajectories and their context. Such VEs typically support them in either reviewing earlier conducted work or experimenting with possible alternatives. In the

  8. Experiments in a Combustion-Driven Shock Tube with an Area Change

    Science.gov (United States)

    Schmidt, B. E.; Bobbitt, B.; Parziale, N. J.; Shepherd, J. E.

    Shock tubes are versatile and useful tools for studying high temperature gas dynamics and the production of hypervelocity flows. High shock speeds are desirable for creating higher enthalpy, pressure, and temperature in the test gas which makes the study of thermo-chemical effects on fluid dynamics possible. Independent of construction and operational cost, free-piston drivers, such as the one used in the T5 facility at Caltech, give the best performance [3]. The high operational cost and long turnaround time of such a facility make a more economical option desirable for smaller-scale testing.

  9. Shock compression of glow discharge polymer (GDP): density functional theory (DFT) simulations and experiments on Sandia's Z-machine

    Science.gov (United States)

    Mattsson, Thomas R.; Cochrane, K. R.; Ao, T.; Lemke, R. W.; Flicker, D. G.; Schoff, M. E.; Blue, B. E.; Hamel, S.; Herrmann, M. C.

    2015-11-01

    Glow discharge polymer (GDP) is used extensively as capsule/ablation material in inertial confinement fusion (ICF) capsules. Accurate knowledge of the equation of state (EOS) under shock and release is particularly important for high-fidelity design, analysis, and optimization of ICF experiments since the capsule material is subject to several converging shocks as well as release towards the cryogenic fuel. We performed Density Functional Theory (DFT) based quantum molecular dynamics (QMD) simulations, to gain knowledge of the behavior of GDP - including the effect of changes in chemical composition. The shock pressures calculated from DFT are compared experimental data taken on magnetically launched flyer plate impact experiments on at Sandia's Z-machine. Large GDP samples were grown in a planar geometry to improve the sample quality and maintained in a nitrogen atmosphere following manufacturing, thus allowing for a direct comparison to the DFT/QMD simulations. Sandia National Laboratories is a multi program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under contract DE-AC04-94AL85000.

  10. Creation of ultra-high-pressure shocks by the collision of laser-accelerated disks: experiment and theory

    International Nuclear Information System (INIS)

    Rosen, M.D.; Phillion, D.W.; Price, R.H.; Campbell, E.M.; Obenschain, S.P.; Whitlock, R.R.; McLean, E.A.; Ripin, B.H.

    1983-01-01

    We have used the SHIVA laser system to accelerate carbon disks to speeds in excess of 100 km/sec. The 3KJ/3 ns pulse, on a 1 mm diameter spot of a single disk produced a conventional shock of about 5 MB. The laser energy can, however, be stored in kinetic motion of this accelerated disk and delivered (reconverted to thermal energy) upon impact with another carbon disk. This collision occurs in a time much shorter than the 3 ns pulse, thus acting as a power amplifier. The shock pressures measured upon impact are estimated to be in the 20 MB range, thus demonstrating the amplification power of this colliding disk technique in creating ultra-high pressures. Theory and computer simulations of this process will be discussed, and compared with the experiment

  11. Dislocation evolution and properties enhancement of GH2036 by laser shock processing: Dislocation dynamics simulation and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ren, X.D., E-mail: renxd@mail.ujs.edu.cn [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Zhou, W.F.; Ren, Y.P.; Xu, S.D.; Liu, F.F. [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Yuan, S.Q. [Research Center of Fluid Machinery Engineering and Technical, Jiangsu University, Zhenjiang 212013 (China); Ren, N.F.; Huang, J.J. [School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China)

    2016-01-27

    This paper systematically investigated the effect of laser shock processing (LSP) on dislocation evolution and microstructure configuration of GH2036 alloy. Surface topography and roughness were tested by Axio CSM 700 microscope. The dislocation configurations were characterized by transmission electron microscope (TEM) and simulated by multi-scale discrete dislocation dynamics (DD) method. The results have confirmed that LSP had a beneficial effect on micro-hardness, which could be increased by 16%, and the surface topography exhibited excellent stability even after thermal cycle. The dislocation density and stress–strain response have strong dependence on laser power intensity. Reasonable agreement between DD simulation and experiments is achieved. The results showed that complex random microstructures can be observed in the shocked surface. The grain refinement mechanism of LSP GH2036 involves dislocation segmentation and twin intersections.

  12. Visible Spectrometer at the Compact Toroid Injection Experiment, the Sustained Spheromak Plasma Experiment and the Alcator C-Mod Tokamak for Doppler Width and Shift Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Graf, A; Howard, S; Horton, R; Hwang, D; May, M; Beiersdorfer, P; McLean, H; Terry, J

    2006-05-15

    A novel Doppler spectrometer is currently being used for ion or neutral velocity and temperature measurements on the Alcator C-Mod Tokamak. The spectrometer has an f/No. of {approx}3.1 and is appropriate for visible light (3500-6700 {angstrom}). The full width at half maximum from a line emitting calibration source has been measured to be as small as 0.4 {angstrom}. The ultimate time resolution is line brightness light limited and on the order of ms. A new photon efficient detector is being used for the setup at C-Mod. Time resolution is achieved by moving the camera during a plasma discharge in a perpendicular direction through the dispersion plane of the spectrometer causing a vertical streaking across the camera face. Initial results from C-Mod as well as previous measurements from the Compact Toroid Injection Experiment (CTIX) and the Sustained Spheromak Plasma Experiment (SSPX) are presented.

  13. Pulsed Polarimetry and magnetic sensing on the Magnetized Shock Experiment (MSX)

    Science.gov (United States)

    Smith, R. J.; Hutchinson, T. M.; Weber, T. E.; Taylor, S. F.; Hsu, S. C.

    2014-10-01

    MSX is uniquely positioned to generate the conditions for collision-less magnetized supercritical shocks with Alvenic Mach numbers (MA) of the order 10 and higher. Significant operational strides have been made in forming plasmas over wide parameter ranges: (Te + Ti) of 10-200 eV, average neof 5-60×10+21 m-3, speeds up to 150 km/s and fields up to 1T with a highest plasma flow MA of 5 to date. The MSX plasma is unique in regards to large plasma size of 10 cm and average β higher than 0.8 making the FRC and the magnetized shock structure candidates for the application of Pulsed Polarimetry, a polarization sensitive Lidar technique. The shock dynamics are presently being investigated using internal probes, interferometry and imaging. Internal probe results and an assessment of the shock parameters will dictate the use of the UW pulsed polarimeter system in which internal ne, Teand B are to be measured. Recent results will be presented. Supported by DOE Office of Fusion Energy Sciences Funding DE-FOA-0000755.

  14. Short pulse duration shock initiation experiments plus ignition and growth modeling on Composition B

    International Nuclear Information System (INIS)

    May, Chadd M; Tarver, Craig M

    2014-01-01

    Composition B (63% RDX, 36% TNT, 1% wax) is still a widely used energetic material whose shock initiation characteristics are necessary to understand. It is now possible to shock initiate Composition B and other secondary explosives at diameters well below their characteristic failure diameters for unconfined self-sustaining detonation. This is done using very high velocity, very thin, small diameter flyer plates accelerated by electric or laser power sources. Recently experimental detonation versus failure to detonate threshold flyer velocity curves for Composition B using several Kapton TM flyer thicknesses and diameters were measured. Flyer plates with diameters of 2 mm successfully detonated Composition B, which has a nominal failure diameter of 4.3 mm. The shock pressures required for these initiations are greater than the Chapman-Jouguet (C-J) pressure in self-sustaining Composition B detonation waves. The initiation process is two-dimensional, because both rear and side rarefactions can affect the shocked Composition B reaction rates. The Ignition and Growth reactive flow model for Composition B is extended to yield accurate simulations of this new threshold velocity data for various flyer thicknesses.

  15. Measuring the flexoelectric coefficient of bulk barium titanate from a shock wave experiment

    Science.gov (United States)

    Hu, Taotao; Deng, Qian; Liang, Xu; Shen, Shengping

    2017-08-01

    In this paper, a phenomenon of polarization introduced by shock waves is experimentally studied. Although this phenomenon has been reported previously in the community of physics, this is the first time to link it to flexoelectricity, the coupling between electric polarization and strain gradients in dielectrics. As the shock waves propagate in a dielectric material, electric polarization is thought to be induced by the strain gradient at the shock front. First, we control the first-order hydrogen gas gun to impact and generate shock waves in unpolarized bulk barium titanate (BT) samples. Then, a high-precision oscilloscope is used to measure the voltage generated by the flexoelectric effect. Based on experimental results, strain elastic wave theory, and flexoelectric theory, a longitudinal flexoelectric coefficient of the bulk BT sample is calculated to be μ 11 = 17.33 × 10 - 6 C/m, which is in accord with the published transverse flexoelectric coefficient. This method effectively suppresses the majority of drawbacks in the quasi-static and low frequency dynamic techniques and provides more reliable results of flexoelectric behaviors.

  16. Shock experiments in range of 10–45 GPa with small multidomain magnetite in porous targets

    Czech Academy of Sciences Publication Activity Database

    Kohout, Tomáš; Pesonen, L. J.; Deutsch, A.; Wünnemann, K.; Nowka, D.; Hornemann, U.; Heikinheimo, E.

    2012-01-01

    Roč. 47, č. 10 (2012), s. 1671-1680 ISSN 1086-9379 Institutional research plan: CEZ:AV0Z30130516 Keywords : shock * magnetite * magnetism * magnetic properties * density porosity Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.800, year: 2012

  17. Optimal Design and Model Validation for Combustion Experiments in a Shock Tube

    KAUST Repository

    Long, Quan; Kim, Daesang; Tempone, Raul; Bisetti, Fabrizio; Farooq, Aamir; Knio, Omar; Prudhomme, Serge

    2014-01-01

    in the reaction rate functions. The control parameters are the initial hydrogen concentration and the temperature. First, we build a polynomial based surrogate model for the observable related to the reactions in the shock tube. Second, we use a novel MAP based

  18. The design of a flexible Global Calorimeter Trigger system for the Compact Muon Solenoid experiment

    Energy Technology Data Exchange (ETDEWEB)

    Brooke, J J [H.H. Wills Physics Lab, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Cussans, D G [H.H. Wills Physics Lab, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Frazier, R J E [H.H. Wills Physics Lab, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Galagedera, S B [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom); Heath, G P [H.H. Wills Physics Lab, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Huckvale, B J [H.H. Wills Physics Lab, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Nash, S J [H.H. Wills Physics Lab, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Newbold, D M [H.H. Wills Physics Lab, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Shah, A A [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX (United Kingdom)

    2007-10-15

    We have developed a novel design of triggering system as part of the pipelined hardware Level-1 trigger logic for the CMS experiment at LHC. The Global Calorimeter Trigger is the last element in the processing of calorimeter data, and provides most of the input to the final Level-1 decision. We present the detailed functional requirements for this system. Our design meets the requirements using generic, configurable Trigger Processing Modules built from commercial programmable logic and high-speed serial data links. We describe the hardware, firmware and software components of this solution. CMS has chosen an alternative solution to build the final trigger system; we discuss the implications of our experiences for future development projects along similar lines.

  19. Dislocation pinning effects induced by nano-precipitates during warm laser shock peening: Dislocation dynamic simulation and experiments

    Science.gov (United States)

    Liao, Yiliang; Ye, Chang; Gao, Huang; Kim, Bong-Joong; Suslov, Sergey; Stach, Eric A.; Cheng, Gary J.

    2011-07-01

    Warm laser shock peening (WLSP) is a new high strain rate surface strengthening process that has been demonstrated to significantly improve the fatigue performance of metallic components. This improvement is mainly due to the interaction of dislocations with highly dense nanoscale precipitates, which are generated by dynamic precipitation during the WLSP process. In this paper, the dislocation pinning effects induced by the nanoscale precipitates during WLSP are systematically studied. Aluminum alloy 6061 and AISI 4140 steel are selected as the materials with which to conduct WLSP experiments. Multiscale discrete dislocation dynamics (MDDD) simulation is conducted in order to investigate the interaction of dislocations and precipitates during the shock wave propagation. The evolution of dislocation structures during the shock wave propagation is studied. The dislocation structures after WLSP are characterized via transmission electron microscopy and are compared with the results of the MDDD simulation. The results show that nano-precipitates facilitate the generation of highly dense and uniformly distributed dislocation structures. The dislocation pinning effect is strongly affected by the density, size, and space distribution of nano-precipitates.

  20. A high-speed, eight-wavelength visible light-infrared pyrometer for shock physics experiments

    Science.gov (United States)

    Wang, Rongbo; Li, Shengfu; Zhou, Weijun; Luo, Zhen-Xiong; Meng, Jianhua; Tian, Jianhua; He, Lihua; Cheng, Xianchao

    2017-09-01

    An eight-channel, high speed pyrometer for precise temperature measurement is designed and realized in this work. The addition of longer-wavelength channels sensitive at lower temperatures highly expands the measured temperature range, which covers the temperature of interest in shock physics from 1500K-10000K. The working wavelength range is 400-1700nm from visible light to near-infrared (NIR). Semiconductor detectors of Si and InGaAs are used as photoelectric devices, whose bandwidths are 50MHz and 150MHz respectively. Benefitting from the high responsivity and high speed of detectors, the time resolution of the pyrometer can be smaller than 10ns. By combining the high-transmittance beam-splitters and narrow-bandwidth filters, the peak spectrum transmissivity of each channel can be higher than 60%. The gray-body temperatures of NaI crystal under shock-loading are successfully measured by this pyrometer.

  1. Experience with extracorporeal shock wave therapy (ESWT) in the United States

    Science.gov (United States)

    Furia, John P.

    2005-04-01

    The purpose of this presentation is to summarize the literature and to report on single treatment, high-energy ESWT for the treatment of chronic plantar fasciitis and lateral epicondylitis. Fifty-three patients (60 heels) were treated with 3800 shock waves. Sixteen patients (19 heels) were active, 21 (22 heels), were moderately active, and 16 (19 heels) were sedentary. Twelve weeks post treatment, mean visual analog scores (VAS) for the entire group improved from 9.2 to 2.4 (plateral epicondylitis were treated with 3200 shock waves. There were 9 workers compensation and 27 non-workers compensation patients. Twelve weeks post treatment, the mean VAS for the entire group improved from 8.0 to 2.5 (plateral epicondylitis.

  2. Experiment and numerical analysis of the NPP pressurizer auxiliary spray line submitted to large thermal shocks

    International Nuclear Information System (INIS)

    Couterot, C.; Geyer, P.; Proix, J.M.

    1994-03-01

    The pressurizer auxiliary spray line of PWR nuclear power plants may be submitted to severe temperature transients during upset conditions: a 325 deg C cold thermal shock in one second is followed by a 200 deg C hot thermal shock. For such transients, the RCC-M French design code rules that prevent the ratcheting deformation hazard are not respected for the components with thickness transition. Consequently, Electricite de France has realized twenty thermal cycles under pressure on a representative mock-up. During these tests, many temperature, strain and diametral variations were measured. No significant ratcheting deformation was detected on all components, except on the 6'' x 2'' x 6'' T-piece, where a weak progressive diameter increase was observed during a few cycles. Moreover, computations of a 2'' socket welding were made with the non linear kinematic hardening Chaboche model which also showed a weak progressive deformation behaviour. (authors). 7 figs., 7 refs

  3. Uniaxial backfill block compaction

    International Nuclear Information System (INIS)

    Koskinen, V.

    2012-05-01

    The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

  4. Application of pressure-sensitive paint in shock-boundary layer interaction experiments

    OpenAIRE

    Seivwright, Douglas L.

    1996-01-01

    Approved for public release; distribution is unlimited A new type of pressure transducer, pressure-sensitive paint, was used to obtain pressure distributions associated with shock-boundary layer interaction. Based on the principle of photoluminescence and the process of oxygen quenching, pressure-sensitive paint provides a continous mapping of a pressure field over a surface of interest. The data measurement and acquisition system developed for use with the photoluminescence sensor was eva...

  5. CFD Validation Experiment of a Mach 2.5 Axisymmetric Shock-Wave/Boundary-Layer Interaction

    Science.gov (United States)

    Davis, David Owen

    2015-01-01

    Preliminary results of an experimental investigation of a Mach 2.5 two-dimensional axisymmetric shock-wave/ boundary-layer interaction (SWBLI) are presented. The purpose of the investigation is to create a SWBLI dataset specifically for CFD validation purposes. Presented herein are the details of the facility and preliminary measurements characterizing the facility and interaction region. These results will serve to define the region of interest where more detailed mean and turbulence measurements will be made.

  6. Success of electromagnetic shock wave lithotripter as monotherapy in large renal calculi—Our experience

    OpenAIRE

    K.S. Meitei; S Gupta; A.K. Singh

    2013-01-01

    Objectives: To evaluate the success of shock wave lithotripsy (SWL) as monotherapy for solitary renal stones larger than 2 cm without ureteral stenting. Hence, if our study result demonstrates acceptable success and safety, we can recommend ESWL as a treatment option for patients with large renal calculi. Subjects and methods: This is a prospective study conducted in the Department of Urology, Regional Institute of Medical Sciences, Imphal, India, from January 2011 to December 2012. A tota...

  7. Performance of waveform digitizers as a compact data acquisition system for the ISMRAN experiment

    International Nuclear Information System (INIS)

    Mitra, A.; Netrakanti, P.K.; Kashyap, V.K.S.; Behera, S.P.; Jha, V.; Mishra, D.K.; Pant, L.M.

    2016-01-01

    The Indian Scintillator Matrix for Reactor Anti-Neutrino (ISMRAN) detector is proposed at the Dhruva reactor, BARC, to measure the anti-neutrinos (υ-bar ) for the purpose of reactor monitoring and sterile neutrino search. A one ton detector, consisting of 100 plastic scintillator bars (10cm x 10cm x 100cm), wrapped with the Gadolinium (Gd) coated mylar foils and coupled with photomultiplier tubes (PMT) at both ends, is planned for this purpose. One of the key components for such an experiment is the development of a dedicated and economical data acquisition system (DAQ) for the detector setup. The FPGA based waveform digitizers are suitable for this purpose, where data from a large number of detectors need to be read out simultaneously. This effectively reduces the burden of the intermediate conventional pulse processing electronics between the detectors and the DAQ. We have procured the CAEN made 16 channel, model V1730, 14bit, 500 MS/s VME based waveform digitizers for this purpose. A series of measurements have been carried out to evaluate the performance of the digitizers. We are also working on the related auxiliary software and data format to be used extensively for ISMRAN DAQ

  8. Compact electrostatic beam optics for multi-element focused ion beams: simulation and experiments.

    Science.gov (United States)

    Mathew, Jose V; Bhattacharjee, Sudeep

    2011-01-01

    Electrostatic beam optics for a multi-element focused ion beam (MEFIB) system comprising of a microwave multicusp plasma (ion) source is designed with the help of two widely known and commercially available beam simulation codes: AXCEL-INP and SIMION. The input parameters to the simulations are obtained from experiments carried out in the system. A single and a double Einzel lens system (ELS) with and without beam limiting apertures (S) have been investigated. For a 1 mm beam at the plasma electrode aperture, the rms emittance of the focused ion beam is found to reduce from ∼0.9 mm mrad for single ELS to ∼0.5 mm mrad for a double ELS, when S of 0.5 mm aperture size is employed. The emittance can be further improved to ∼0.1 mm mrad by maintaining S at ground potential, leading to reduction in beam spot size (∼10 μm). The double ELS design is optimized for different electrode geometrical parameters with tolerances of ±1 mm in electrode thickness, electrode aperture, inter electrode distance, and ±1° in electrode angle, providing a robust design. Experimental results obtained with the double ELS for the focused beam current and spot size, agree reasonably well with the simulations.

  9. Stabilization of compactible waste

    International Nuclear Information System (INIS)

    Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1990-09-01

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs

  10. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    Energy Technology Data Exchange (ETDEWEB)

    Adjei, Daniel, E-mail: nana.adjeidan@gmail.com [Institute of Optoelectronics, Military University of Technology, 2, Kaliskiego Str., 00-908 Warsaw (Poland); Radiation Protection Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Accra (Ghana); Ayele, Mesfin Getachew; Wachulak, Przemyslaw; Bartnik, Andrzej; Wegrzynski, Łukasz; Fiedorowicz, Henryk [Institute of Optoelectronics, Military University of Technology, 2, Kaliskiego Str., 00-908 Warsaw (Poland); Vyšín, Luděk [Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Faculty of Nuclear Sciences and Engineering Physics, Czech Technical University in Prague, Břehová 7, 115 19 Prague 1 (Czech Republic); Wiechec, Anna; Lekki, Janusz; Kwiatek, Wojciech M. [Institute of Nuclear Physics, Polish Academy of Sciences, 152, Radzikowskiego Str., 31-342 Cracow (Poland); Pina, Ladislav [Faculty of Nuclear Sciences and Engineering Physics, Czech Technical University in Prague, Břehová 7, 115 19 Prague 1 (Czech Republic); Davídková, Marie [Institute of Nuclear Physics, Czech Academy of Sciences, Řež (Czech Republic); Juha, Libor [Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic)

    2015-12-01

    A desk-top laser-produced plasma (LPP) source of soft X-rays (SXR) has been developed for radiobiology research. The source is based on a double-stream gas puff target, irradiated with the focused beam of a commercial Nd:YAG laser. The source has been optimized to get a maximum photon emission from LPP in the X-ray “water window” spectral wavelength range from 2.3 nm (i.e., an absorption edge of oxygen) to 4.4 nm (i.e., an absorption edge of carbon) (280–540 eV in photon energy units) by using argon gas-puff target and spectral filtering by free-standing thin foils. The present source delivers nanosecond pulses of soft X-rays at a fluence of about 4.2 × 10{sup 3} photons/μm{sup 2}/pulse on a sample placed inside the vacuum chamber. In this paper, the source design, radiation output characterization measurements and initial irradiation experiments are described. The source can be useful in addressing observations related to biomolecular, cellular and organisms’ sensitivity to pulsed radiation in the “water window”, where carbon atoms absorb X-rays more strongly than the oxygen, mostly present in water. The combination of the SXR source and the radiobiology irradiation layout, reported in this article, make possible a systematic investigation of relationships between direct and indirect action of ionizing radiation, an increase of a local dose in carbon-rich compartments of the cell (e.g., lipid membranes), an experimental estimation of a particular role of the Auger effect (in particular in carbon atoms) in the damage to biological systems, and the study of ionization/excitation-density (LET – Linear Energy Transfer) and dose-rate effects in radiobiology.

  11. Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D., E-mail: deyongl@uci.edu; Heidbrink, W. W.; Hao, G. Z.; Zhu, Y. B. [Departments of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Tritz, K. [Departments of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Fredrickson, E. D. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2016-11-15

    A compact and multi-view solid state neutral particle analyzer (SSNPA) diagnostic based on silicon photodiode arrays has been successfully tested on the National Spherical Torus Experiment-Upgrade. The SSNPA diagnostic provides spatially, temporally, and pitch-angle resolved measurements of fast-ion distribution by detecting fast neutral flux resulting from the charge exchange (CX) reactions. The system consists of three 16-channel subsystems: t-SSNPA viewing the plasma mid-radius and neutral beam (NB) line #2 tangentially, r-SSNPA viewing the plasma core and NB line #1 radially, and p-SSNPA with no intersection with any NB lines. Due to the setup geometry, the active CX signals of t-SSNPA and r-SSNPA are mainly sensitive to passing and trapped particles, respectively. In addition, both t-SSNPA and r-SSNPA utilize three vertically stacked arrays with different filter thicknesses to obtain coarse energy information. The experimental data show that all channels are operational. The signal to noise ratio is typically larger than 10, and the main noise is x-ray induced signal. The active and passive CX signals are clearly observed on t-SSNPA and r-SSNPA during NB modulation. The SSNPA data also indicate significant losses of passing particles during sawteeth, while trapped particles are weakly affected. Fluctuations up to 120 kHz have been observed on SSNPA, and they are strongly correlated with magnetohydrodynamics instabilities.

  12. Design of experiment approach for sintering study of nanocrystalline SiC fabricated using plasma pressure compaction

    Directory of Open Access Journals (Sweden)

    Bothara M.G.

    2009-01-01

    Full Text Available Plasma pressure compaction (P2C is a novel sintering technique that enables the consolidation of silicon carbide with a nanoscale microstructure at a relatively low temperature. To achieve a high final density with optimized mechanical properties, the effects of various sintering factors pertaining to the temperature-time profile and pressure were characterized. This paper reports a design of experiment approach used to optimize the processing for a 100 nm SiC powder focused on four sintering factors: temperature, time, pressure, and heating rate. Response variables included the density and mechanical properties. A L9 orthogonal array approach that includes the signal-to-noise (S/N ratio and analysis of variance (ANOVA was employed to optimize the processing factors. All of the sintering factors have significant effect on the density and mechanical properties. A final density of 98.1% was achieved with a temperature of 1600°C, hold time of 30 min, pressure of 50 MPa, and heating rate of 100°C/min. The hardness reached 18.4 GPa with a fracture toughness of 4.6 MPa√m, and these are comparable to reports from prior studies using higher consolidation temperatures.

  13. The Terabit/s Super-Fragment Builder and Trigger Throttling System for the Compact Muon Solenoid Experiment at CERN

    CERN Document Server

    Bauer, Gerry; Boyer, Vincent; Branson, James; Brett, Angela; Cano, Eric; Carboni, Andrea; Ciganek, Marek; Cittolin, Sergio; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gómez-Reino, Robert; Gulmini, Michele; Gutíerrez-Mlot, Esteban; Gutleber, Johannes; Jacobs, Claude; Kim, Jin Cheol; Klute, Markus; Lipeles, Elliot; Lopez-Perez, Juan Antonio; Maron, Gaetano; Meijers, Frans; Meschi, Emilio; Moser, Roland; Murray, Steven; Oh, Alexander; Orsini, Luciano; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Pollet, Lucien; Rácz, Attila; Sakulin, Hannes; Sani, Matteo; Schieferdecker, Philipp; Schwick, Christoph; Sumorok, Konstanty; Suzuki, Ichiro; Tsirigkas, Dimitrios

    2007-01-01

    The Data Acquisition System of the Compact Muon Solenoid experiment at the Large Hadron Collider reads out event fragments of an average size of 2 kilobytes from around 650 detector front-ends at a rate of up to 100 kHz. The first stage of event-building is performed by the Super-Fragment Builder employing custom-built electronics and a Myrinet optical network. It reduces the number of fragments by one order of magnitude, thereby greatly decreasing the requirements for the subsequent event-assembly stage. By providing fast feedback from any of the front-ends to the trigger, the Trigger Throttling System prevents buffer overflows in the front-end electronics due to variations in the size and rate of events or due to back-pressure from the down-stream event-building and processing. This paper reports on new performance measurements and on the recent successful integration of a scaled-down setup of the described system with the trigger and with front-ends of all major sub-detectors. The on-going commissioning of...

  14. Time-resolved characterization and energy balance analysis of implosion core in shock-ignition experiments at OMEGA

    International Nuclear Information System (INIS)

    Florido, R.; Mancini, R. C.; Nagayama, T.; Tommasini, R.; Delettrez, J. A.; Regan, S. P.

    2014-01-01

    Time-resolved temperature and density conditions in the core of shock-ignition implosions have been determined for the first time. The diagnostic method relies on the observation, with a streaked crystal spectrometer, of the signature of an Ar tracer added to the deuterium gas fill. The data analysis confirms the importance of the shell attenuation effect previously noted on time-integrated spectroscopic measurements of thick-wall targets [R. Florido et al., Phys. Rev. E 83, 066408 (2011)]. This effect must be taken into account in order to obtain reliable results. The extracted temperature and density time-histories are representative of the state of the core during the implosion deceleration and burning phases. As a consequence of the ignitor shock launched by the sharp intensity spike at the end of the laser pulse, observed average core electron temperature and mass density reach T ∼ 1100 eV and ρ ∼ 2 g/cm 3 ; then temperature drops to T ∼ 920 eV while density rises to ρ ∼ 3.4 g/cm 3 about the time of peak compression. Compared to 1D hydrodynamic simulations, the experiment shows similar maximum temperatures and smaller densities. Simulations do not reproduce all observations. Differences are noted in the heating dynamics driven by the ignitor shock and the optical depth time-history of the compressed shell. Time-histories of core conditions extracted from spectroscopy show that the implosion can be interpreted as a two-stage polytropic process. Furthermore, an energy balance analysis of implosion core suggests an increase in total energy greater than what 1D hydrodynamic simulations predict. This new methodology can be implemented in other ICF experiments to look into implosion dynamics and help to understand the underlying physics

  15. Time-resolved characterization and energy balance analysis of implosion core in shock-ignition experiments at OMEGA

    Energy Technology Data Exchange (ETDEWEB)

    Florido, R., E-mail: ricardo.florido@ulpgc.es; Mancini, R. C.; Nagayama, T. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); Tommasini, R. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Delettrez, J. A.; Regan, S. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2014-10-15

    Time-resolved temperature and density conditions in the core of shock-ignition implosions have been determined for the first time. The diagnostic method relies on the observation, with a streaked crystal spectrometer, of the signature of an Ar tracer added to the deuterium gas fill. The data analysis confirms the importance of the shell attenuation effect previously noted on time-integrated spectroscopic measurements of thick-wall targets [R. Florido et al., Phys. Rev. E 83, 066408 (2011)]. This effect must be taken into account in order to obtain reliable results. The extracted temperature and density time-histories are representative of the state of the core during the implosion deceleration and burning phases. As a consequence of the ignitor shock launched by the sharp intensity spike at the end of the laser pulse, observed average core electron temperature and mass density reach T ∼ 1100 eV and ρ ∼ 2 g/cm{sup 3}; then temperature drops to T ∼ 920 eV while density rises to ρ ∼ 3.4 g/cm{sup 3} about the time of peak compression. Compared to 1D hydrodynamic simulations, the experiment shows similar maximum temperatures and smaller densities. Simulations do not reproduce all observations. Differences are noted in the heating dynamics driven by the ignitor shock and the optical depth time-history of the compressed shell. Time-histories of core conditions extracted from spectroscopy show that the implosion can be interpreted as a two-stage polytropic process. Furthermore, an energy balance analysis of implosion core suggests an increase in total energy greater than what 1D hydrodynamic simulations predict. This new methodology can be implemented in other ICF experiments to look into implosion dynamics and help to understand the underlying physics.

  16. Dynamic fragmentation of laser shock-melted tin: experiment and modelling

    Energy Technology Data Exchange (ETDEWEB)

    De Resseguier, T. [CNRS ENSMA, Lab Combust and Deton, F-86961 Futuroscope (France); Signor, L.; Dragon, A. [CNRS ENSMA, Mecan and Phys Mat Lab, F-86961 Futuroscope (France); Signor, L.; Roy, G. [CEA Valduc, 21 - Is-sur-Tille (France)

    2010-07-01

    Dynamic fragmentation of shock-loaded metals is an issue of considerable importance for both basic science and a variety of technological applications, such as pyrotechnics or inertial confinement fusion, the latter involving high energy laser irradiation of thin metallic shells. Whereas spall fracture in solid materials has been extensively studied for many years, little data can be found yet about the evolution of this phenomenon after partial or full melting on compression or on release. Here, we present an investigation of dynamic fragmentation in laser shock-melted tin, from the 'micro-spall' process (ejection of a cloud of fine droplets) occurring upon reflection of the compressive pulse from the target free surface, to the late rupture observed in the un-spalled melted layer (leading to the formation of larger spherical fragments). Experimental results consist of time-resolved velocity measurements and post-shock observations of recovered targets and fragments. They provide original information regarding the loss of tensile strength associated with melting, the cavitation mechanism likely to occur in the melted metal, the sizes of the subsequent fragments and their ejection velocities. A theoretical description based on an energetic approach adapted to the case of a liquid metal is implemented as a failure criterion in a one-dimensional hydro-code including a multi-phase equation of state for tin. The resulting predictions of the micro-spall process are compared with experimental data. In particular, the use of a new experimental technique to quantify the fragment size distributions leads to a much better agreement with theory than previously reported. Finally, a complementary approach focused on cavitation is proposed to evaluate the role of this phenomenon in the fragmentation of the melted metal. (authors)

  17. Extracorporeal Shock-wave Lithotripsy Success Rate and Complications: Initial Experience at Sultan Qaboos University Hospital

    Directory of Open Access Journals (Sweden)

    Mohammed S. Al-Marhoon

    2013-07-01

    Full Text Available Objective: To assess the efficacy and safety of extracorporeal shock wave lithotripsy with Modularis Vario Siemens in the management of patients with renal and ureteral stones.Methods: Between 2007 and 2009, 225 outpatients were treated with Siemens Modularis Vario lithotripter at Sultan Qaboos University Hospital. Stone size, location, total number of shockwaves, stone-free rate, complications and adjunctive interventions were investigated. Chi-Square and Logistic Regression analyses were used, with p<0.05 set as the level of significance.Results: Of the 225 initial consecutive patients who underwent extracorporeal shock wave lithotripsy, 192 (85% had renal stones and 33 (15% had ureteric stones. The mean±SD stone size was 11.3 ± 4.5 mm, while the mean age of the patients was 39.9 ± 12.8 years with 68.5% males. The mean renal stone size was 11.6 ± 4.7 mm; a mean of 1.3 sessions was required. The mean ureteric stone size was 9.9 ± 3 mm; and a mean of 1.3 sessions was required. Treatment success (defined as complete clearance of ureteric stones, stone-free or clinically insignificant residual fragments of <4 mm for renal stones was 74% for renal stones and 88% for ureteric stones. Additional extracorporeal shock wave lithotripsy and ureteroscopy were the most adjunctive procedures used for stone clearance. Complications occurred in 74 patients (38.5% with renal stones and 13 patients (39.4% with uretetric stones. The most common complication was loin pain (experienced by 16.7% with renal stones and 21% with ureteric stones. Severe renal colic mandating admission occurred in 2% of patients with renal stones and 6% of patients with ureteric stones. In patients with renal stone, steinstrasse occurred in 3.6% and infection post extracorporeal shock wave lithotripsy in 0.5%. Using Multivariate Logistic Regression analysis, factors found to have significant effect on complete stone clearance were serum creatinine (p=0.004 and the number of

  18. Airborne In-Situ Measurements of Formaldehyde Over California: First Results from the Compact Formaldehyde Fluorescence Experiment (COFFEE) Instrument

    Science.gov (United States)

    Marrero, Josette Elizabeth; Saint Clair, Jason; Yates, Emma L.; Gore, Warren; Swanson, Andrew K.; Iraci, Laura T.; Hanisco, Thomas F.

    2016-01-01

    Formaldehyde (HCHO) is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere, playing a role multiple atmospheric processes. Measurements of HCHO can be used to help quantify convective transport, the abundance of VOCs, and ozone production in urban environments. The Compact Formaldehyde FluorescencE Experiment (COFFEE) instrument uses Non-Resonant Laser Induced Fluorescence (NR-LIF) to detect trace concentrations of HCHO as part of the Alpha Jet Atmospheric eXperiment (AJAX) payload. Developed at NASA GSFC, COFFEE is a small, low maintenance instrument with a sensitivity of 100 pptv and a quick response time (1 sec). The COFFEE instrument has been customized to fit in an external wing pod on the Alpha Jet aircraft based at NASA ARC. The instrument can operate over a broad range of altitudes, from boundary layer to lower stratosphere, making it well suited for the Alpha Jet, which can access altitudes from the surface up to 40,000 ft. Results of the first COFFEE science flights preformed over the California's Central Valley will be presented. Boundary layer measurements and vertical profiles in the tropospheric column will both be included. This region is of particular interest, due to its elevated levels of HCHO, revealed in satellite images, as well as its high ozone concentrations. In addition to HCHO, the AJAX payload includes measurements of atmospheric ozone, methane, and carbon dioxide. Formaldehyde is one of the few urban pollutants that can be measured from space. Plans to compare in-situ COFFEE data with satellite-based HCHO observations such as those from OMI (Aura) and OMPS (SuomiNPP) will also be presented.

  19. Shock recovery experiments in the range of 10 to 45 GPa - comparison of results of synthetic magnetite and terrestrial diabase

    Czech Academy of Sciences Publication Activity Database

    Kohout, Tomáš; Pesonen, L.; Deutsch, A.; Honnermann, U.

    89 /53/, Fall Meeting Supplement (2008), , GP21C-0790-GP21C-0790 ISSN 0096-3941. [American Geophysical Union Fall Meeting. 15.12.2008-19.12.2008, San Francisco] Institutional research plan: CEZ:AV0Z30130516 Keywords : shock experiments * magnetite * diabase Subject RIV: DE - Earth Magnetism, Geodesy, Geography http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=kohout&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c766%7c5433%7cShock%20recovery%20experiments%20in%20the%20range%20of%2010%20to%2045%20GPa%20-%20comparison%20of%20results%20of%20synthetic%20magnetite%20and%20terrestrial%20diabase%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c19257669%2019263102%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt

  20. Influence of the gripping fixture on the modified compact tension test results: Evaluation of the experiments on cylindrical concrete specimens

    Czech Academy of Sciences Publication Activity Database

    Holušová, T.; Lozano, M.; Canteli, A.; Komárková, T.; Kocáb, D.; Seitl, Stanislav

    2015-01-01

    Roč. 15, č. 2 (2015) ISSN 1804-4824 Institutional support: RVO:68081723 Keywords : Modified compact tension test * fracture parametr * Cementitious composites * Aramis measurement * grips Subject RIV: JL - Materials Fatigue, Friction Mechanics

  1. Pressure vessel fracture studies pertaining to a PWR LOCA-ECC thermal shock: experiments TSE-3 and TSE-4 and update of TSE-1 and TSE-2 analysis

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Bolt, S.E.

    1977-01-01

    The LOCA-ECC Thermal Shock Program was established to investigate the potential for flaw propagation in pressurized-water reactor (PWR) vessels during injection of emergency core coolant following a loss-of-coolant accident. Studies thus far have included fracture mechanics analyses of typical PWRs, the design and construction of a thermal shock test facility, determination of material properties for test specimens, and four thermal shock experiments with 0.53-m-OD (21-in.) by 0.15-m-wall (6-in.) cylindrical test specimens. In the first experiment, initiation was not expected and did not occur, although there was a small amount of subcritical crack growth. In the second experiment, initiation of a semicircular flaw took place as expected; the final length along the surface was about four times the initial length, but there was no radial growth. The third and fourth experiments were similar, and the long axial flaw initiated in good agreement with predictions

  2. Characterization of Shock Effects in Calcite by Raman Spectroscopy: Results of Experiments

    Science.gov (United States)

    Bell, M. S.

    2016-01-01

    Carbonates comprise approx. 20% by volume of present day Earth's sedimentary rocks and store most of the terrestrial CO2 inventory. Some of the oldest meta-sedimentary rocks found on Earth contain abundant carbonate from which impact-induced release of CO2 could have played a role in the formation and evolution of the atmosphere. Carbonates are also present in the target materials for approx. 30% of all terrestrial impact structures including large impacts such as Chicxulub which happened to occur at a location with extraordinarily thick platform carbonate 3-6 km deep. The impact release of CO2 from carbonates can cause global warming as a result of the well-known greenhouse effect and have subsequent effects on climate and biota. Therefore, the shock behavior of calcite is important in understanding the Cretaceous-Paleogene event and other impacts with carbonate-bearing sediments in their target(s) such as Mars and some asteroids. A comprehensive survey utilizing a variety of techniques to characterize the effects manifest in Calcite (Iceland Spar) experimentally shocked to 60.8 GPa has been completed. Results of analysis by Raman Spectroscopy are reported here.

  3. Experience of extracorporeal shock wave lithotripsy for kidney and upper ureteric stones by electromagnetic lithotripter

    International Nuclear Information System (INIS)

    Wazir, B.G.; Haq, M.I.H.; Faheem-ul-Haq; Nawaz, A.; Nawaz, A.; Ikramullah; Jamil, M.

    2010-01-01

    Background: Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive treatment of urinary stones which breaks them, by using externally applied, focused, high intensity acoustic pulse, into smaller pieces so that they can pass easily through ureter. Shock wave generation, focusing, coupling and stone localisation by fluoroscope or ultrasound are the basic components of ESWL. ESWL has some complications and is contraindicated in certain situations. The aim of this study was to evaluate the effectiveness and safety of ESWL in kidney and upper ureteric stones by Electromagnetic Lithotriptor. Methods: All adult patients with renal and upper ureteric stones having a diameter of up to 1 Cm were included in the study. Basic evaluation such as history, examination, ultrasound and excretory urography were performed. Electromagnetic lithotripsy was done and data were collected on a printed proforma from January 1, 2008 to March 30, 2009 in Institute of Kidney Diseases, Peshawar. Results: Out of a total of 625 patients 463 were male and 162 were female; 67.36% of patients were having renal stones, 23.84% upper ureteric and 8.8% both renal and ureteric stones. Complications noted were renal colic in 9.76%, haematuria in 3.2%, stein strasse in 2.72%, and fever in 1.12% of patients. The stone free rate was 89% and 7% of patients were having stone fragments <4 mm. ESWL failed in 4% of patients. Conclusion: ESWL is a safe and effective way of treating kidney and upper ureteric stones. (author)

  4. Analogy between soap film and gas dynamics. II. Experiments on one-dimensional motion of shock waves in soap films

    Energy Technology Data Exchange (ETDEWEB)

    Wen, C.Y.; Chang-Jian, S.K.; Chuang, M.C. [Department of Mechanical Engineering, Da-Yeh University, Chang-Hwa (Taiwan)

    2003-02-01

    This paper presents an experimental investigation of one-dimensional moving shock waves in vertical soap films. The shock waves were generated by bursting the films with a perforating spark. Images of propagating shock waves and small disturbances were recorded using a fast line scan CCD camera. An aureole and a shock wave preceding the rim of the expanding hole were clearly observed. These images are similar to the x-t diagrams in gas dynamics and give the velocities of shock and sound waves. The moving shock waves cause jumps in thickness. The variations of the induced Mach number, M{sub 2} and the ratio of film thickness across the shock wave, {delta}{sub 2}/{delta}{sub 1}, are plotted versus the shock Mach number, M{sub s}. Both results suggest that soap films are analogous to compressible gases with a specific heat ratio of {gamma}{approx_equal}1.0. (orig.)

  5. Computational methods for fracture mechanics analysis of pressurized-thermal-shock experiments

    International Nuclear Information System (INIS)

    Bass, B.R.; Bryan, R.H.; Bryson, J.W.; Merkle, J.G.

    1984-01-01

    Extensive computational analyses are required to determine material parameters and optimum pressure-temperature transients compatible with proposed pressurized-thermal-shock (PTS) test scenarios and with the capabilities of the PTS test facility at the Oak Ridge National Laboratory (ORNL). Computational economy has led to the application of techniques suitable for parametric studies involving the analysis of a large number of transients. These techniques, which include analysis capability for two- and three-dimensional (2-D and 3-D) superposition, inelastic ligament stability, and upper-shelf arrest, have been incorporated into the OCA/USA computer program. Features of the OCA/USA program are discussed, including applications to the PTS test configuration

  6. Computational methods for fracture mechanics analysis of pressurized-thermal-shock experiments

    International Nuclear Information System (INIS)

    Bass, B.R.; Bryan, R.H.; Bryson, J.W.; Merkle, J.G.

    1984-01-01

    Extensive computational analyses are required to determine material parameters and optimum pressure-temperature transients compatible with proposed pressurized-thermal-shock (PTS) test scenarios and with the capabilities of the PTS test facility at the Oak Ridge National Laboratory (ORNL). Computational economy has led to the application of techniques suitable for parametric studies involving the analysis of a large number of transients. These techniques, which include analysis capability for two- and three-dimensional (2-D and 3-D) superposition, inelastic ligament stability, and upper-shelf arrest, have been incorporated into the OCA/ USA computer program. Features of the OCA/USA program are discussed, including applications to the PTS test configuration. (author)

  7. Violent flows in aqueous foams III: physical multi-phase model comparison with aqueous foam shock tube experiments

    Science.gov (United States)

    Redford, J. A.; Ghidaglia, J.-M.; Faure, S.

    2018-06-01

    Mitigation of blast waves in aqueous foams is a problem that has a strong dependence on multi-phase effects. Here, a simplified model is developed from the previous articles treating violent flows (D'Alesio et al. in Eur J Mech B Fluids 54:105-124, 2015; Faure and Ghidaglia in Eur J Mech B Fluids 30:341-359, 2011) to capture the essential phenomena. The key is to have two fluids with separate velocities to represent the liquid and gas phases. This allows for the interaction between the two phases, which may include terms for drag, heat transfer, mass transfer due to phase change, added mass effects, to be included explicitly in the model. A good test for the proposed model is provided by two experimental data sets that use a specially designed shock tube. The first experiment has a test section filled with spray droplets, and the second has a range of aqueous foams in the test section. A substantial attenuation of the shock wave is seen in both cases, but a large difference is observed in the sound speeds. The droplets cause no observable change from the air sound speed, while the foams have a reduced sound speed of approximately 50-75 m/s . In the model given here, an added mass term is introduced in the governing equations to capture the low sound speed. The match between simulation and experiment is found to be satisfactory for both droplets and the foam. This is especially good when considering the complexity of the physics and the effects that are unaccounted for, such as three-dimensionality and droplet atomisation. The resulting statistics illuminate the processes occurring in such flows.

  8. Fibre reinforced self-compacting concrete flow simulations in comparison with l-box experiments using carbopol

    DEFF Research Database (Denmark)

    Svec, Oldrich; Skocek, Jan; Olesen, John Forbes

    An evolution of distribution and orientation of fibres in the fibre reinforced self-compacting concrete during the casting process is an important matter as the final orientation and distribution of fibres can significantly influence mechanical properties of the structural elements. A two-way cou...

  9. FEM simulation of the die compaction of pharmaceutical products: influence of visco-elastic phenomena and comparison with experiments.

    Science.gov (United States)

    Diarra, Harona; Mazel, Vincent; Busignies, Virginie; Tchoreloff, Pierre

    2013-09-10

    This work studies the influence of visco-elastic behavior in the finite element method (FEM) modeling of die compaction of pharmaceutical products and how such a visco-elastic behavior may improve the agreement between experimental and simulated compression curves. The modeling of the process was conducted on a pharmaceutical excipient, microcrystalline cellulose (MCC), by using Drucker-Prager cap model coupled with creep behavior in Abaqus(®) software. The experimental data were obtained on a compaction simulator (STYLCAM 200R). The elastic deformation of the press was determined by performing experimental tests on a calibration disk and was introduced in the simulation. Numerical optimization was performed to characterize creep parameters. The use of creep behavior in the simulations clearly improved the agreement between the numerical and experimental compression curves (stresses, thickness), mainly during the unloading part of the compaction cycle. For the first time, it was possible to reproduce numerically the fact that the minimum tablet thickness is not obtained at the maximum compression stress. This study proves that creep behavior must be taken into account when modeling the compaction of pharmaceutical products using FEM methods. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Double Shock Experiments Performed at -55°C on LX-17 with Reactive Flow Modeling to Understand the Reacted Equation of State

    Science.gov (United States)

    Dehaven, Martin R.; Vandersall, Kevin S.; Strickland, Shawn L.; Fried, Laurence E.; Tarver, Craig M.

    2017-06-01

    Experiments were performed at -55°C to measure the reacted state of LX-17 (92.5% TATB and 7.5% Kel-F by weight) using a double shock technique using two flyer materials (with known properties) mounted on a projectile that send an initial shock through the material close to the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. Information on the reacted state is obtained by measuring the relative timing and magnitude of the first and second shock waves. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include a comparison to prior work at ambient temperature, the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. Extracorporeal shock wave lithotripsy in the treatment of pediatric urolithiasis: a single institution experience

    Directory of Open Access Journals (Sweden)

    Konstantinos N. Stamatiou

    2010-12-01

    Full Text Available PURPOSE: To compare the efficacy and safety of the electromagnetic lithotripter in the treatment of pediatric lithiasis to that of the earlier electrohydraulic model. MATERIALS AND METHODS: Two groups of children with lithiasis aged between 10 and 180 months who underwent extracorporeal shock wave lithotripsy (ESWL. In the first group (26 children, ESWL was performed by using the electrohydraulic MPL 9000X Dornier lithotripter between 1994 and 2003 while in the second group (19 children the electromagnetic EMSE 220 F-XP Dornier lithotripter was used from April 2003 to May 2006. RESULTS: In the first group, 21/26 children (80.7% were stone free at first ESWL session. Colic pain resolved by administration of an oral analgesic in 6 (23%, brief hematuria (< 24 h resolved with increased fluid intake in 5 (19.2%, while slightly elevated body temperature (< 38°C occurred in 4 (15.3%. Four children (15.3% failed to respond to treatment and were treated with ureteroscopy. In the second group 18/19 children were completely stone free at first ESWL session (94.7%. Complications were infrequent and of minor importance: colic pain treated with oral analgesic occurred in 1 (5.26%, brief hematuria (< 24 h, resolved with increased fluid intake in 4 (21% and slightly elevated body temperature (< 38°C monitored for 48 hours occurred in 6 (31.5%. Statistical analysis showed that electromagnetic lithotripter is more efficacious and safer than the earlier electrohydraulic model. CONCLUSIONS: Technological development not only has increased efficacy and safety of lithotripter devices in treating pediatric lithiasis, but it also provided less painful lithotripsy by eliminating the need for general anesthesia.

  12. Shock-induced modification of the structure of yttria stabilised zirconia powder

    International Nuclear Information System (INIS)

    Frazer, B.G.; Killen, P.D.; Page, N.W.; Charleson, S.W.

    1999-01-01

    Full text: Powder samples of 3 mol% yttria stabilised zirconia were shock compacted in Russia using the explosive flyer plate compaction technique in which a flyer plate is driven by an explosive charge to impact on the surface of a target fixture containing the powder. In these experiments the impact velocity of the flyer plate was approximately 2130 m.s -1 . Initial precompaction densities of 30% and 60% of solid phase densities were used in the shock compaction process. The precompaction densities were responsible for the different values of the shock strength transmitted to the sample. These pressures were 5 GPa and 16 GPa (for the 30% and 60% dense samples respectively). Fragments of all shock compacted samples were obtained for analysis with the only exception being one of the 5 GPa samples which remained intact and was encased in a resin. X-Ray diffraction scans of the recovered samples were analysed using the Rietveld refinement program GSAS. Results show significant changes in crystallite size and strain and an alteration to the shape of the monoclinic lattice as well as the pressure induced phase change from cubic to tetragonal described in another paper. Copyright (1999) Australian X-ray Analytical Association Inc

  13. Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

    International Nuclear Information System (INIS)

    Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J.

    2015-01-01

    Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion

  14. Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

    Science.gov (United States)

    Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J.

    2015-12-01

    Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion.

  15. Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J. [Lawrence Livermore National Laboratory, Livermore, California, 94550 (United States)

    2015-12-15

    Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion.

  16. Oxidized Metal Powders for Mechanical Shock and Crush Safety Enhancers; TOPICAL

    International Nuclear Information System (INIS)

    GARINO, TERRY J.

    2002-01-01

    The use of oxidized metal powders in mechanical shock or crush safety enhancers in nuclear weapons has been investigated. The functioning of these devices is based on the remarkable electrical behavior of compacts of certain oxidized metal powders when subjected to compressive stress. For example, the low voltage resistivity of a compact of oxidized tantalum powder was found to decrease by over six orders of magnitude during compaction between 1 MPa, where the thin, insulating oxide coatings on the particles are intact, to 10 MPa, where the oxide coatings have broken down along a chain of particles spanning the electrodes. In this work, the behavior of tantalum and aluminum powders was investigated. The low voltage resistivity during compaction of powders oxidized under various conditions was measured and compared. In addition, the resistivity at higher voltages and the dielectric breakdown strength during compaction were also measured. A key finding was that significant changes in the electrical properties persist after the removal of the stress so that a mechanical shock enhancer is feasible. This was verified by preliminary shock experiments. Finally, conceptual designs for both types of enhancers are presented

  17. Comparative modelling of laboratory experiments for the hydro-mechanical behaviour of a compacted bentonite–sand\

    Czech Academy of Sciences Publication Activity Database

    Millard, A.; Mokni, N.; Barnichon, J. D.; Tatcher, K. E.; Bond, A.; Mc Dermott, C.; Blaheta, Radim; Michalec, Zdeněk; Hasal, Martin; Nguyen, T. S.; Nasir, O.; Fedors, S.; Yi, H.; Kolditz, O.

    2016-01-01

    Roč. 75, č. 20 (2016), s. 1311-1327 ISSN 1866-6280. [DECOVALEX 2015 /8./. Wakkanai, 13.10.2015-16.10.2015] Institutional support: RVO:68145535 Keywords : hydro-mechanical (hm) coupling * numerical modelling * sealing system s * compacted bentonite–sand mixture Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.569, year: 2016 http://link.springer.com/article/10.1007/s12665-016-6118-z

  18. Numerical analysis of experiments on the generation of shock waves in aluminium under indirect (X-ray) action on the Iskra-5 facility

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenko, S V; Dolgoleva, G V; Novikova, E A

    2013-07-31

    The dynamics of laser and X-ray radiation fields in experiments with cylindrical converter boxes (illuminators), which had earlier been carried out on the Iskra-5 laser facility (the second harmonic of iodine laser radiation, {lambda} = 0.66 {mu}m) was investigated in a sector approximation using the SND-LIRA numerical technique. In these experiments, the X-ray radiation temperature in the box was determined by measuring the velocity of the shock wave generated in the sample under investigation, which was located at the end of the cylindrical illuminator. Through simulations were made using the SND-LIRA code, which took into account the absorption of laser driver radiation at the box walls, the production of quasithermal radiation, as well as the formation and propagation of the shock wave in the sample under investigation. An analysis of the experiments permits determining the electron thermal flux limiter f: for f = 0.03 it is possible to match the experimental scaling data for X-ray in-box radiation temperature to the data of our simulations. The shock velocities obtained from the simulations are also consistent with experimental data. In particular, in the experiment with six laser beams (and a laser energy E{sub L} = 1380 J introduced into the box) the velocity of the shock front (determined from the position of a laser mark) after passage through a 50-{mu}m thick base aluminium layer was equal to 35{+-}1.6 km s{sup -1}, and in simulations to 36 km s{sup -1}. In the experiment with four laser beams (for E{sub L} = 850 J) the shock velocity (measured from the difference of transit times through the base aluminium layer and an additional thin aluminium platelet) was equal to 30{+-}3.6 km s{sup -1}, and in simulations to 30 km s{sup -1}. (interaction of laser radiation with matter)

  19. A dynamic analysis of crack propagation and arrest of pressurized thermal shock experiments (PTSE)

    International Nuclear Information System (INIS)

    Brickstad, B.; Nilsson, F.

    1984-01-01

    The PTS-experiments performed at ORNL are dynamically analysed by aid ot a two-dimensional FEM-code with capability of simulating rapid crack growth.It is found that both a quasistatic and a dynamic treatment agree well with the experimentally obtained crack arrest lengths. (author)

  20. Shock Prevention

    Science.gov (United States)

    1978-01-01

    The electrician pictured is installing a General Electric Ground Fault Interrupter (GFI), a device which provides protection against electrical shock in the home or in industrial facilities. Shocks due to defective wiring in home appliances or other electrical equipment can cause severe burns, even death. As a result, the National Electrical Code now requires GFIs in all new homes constructed. This particular type of GFI employs a sensing element which derives from technology acquired in space projects by SCI Systems, Inc., Huntsville, Alabama, producer of sensors for GE and other manufacturers of GFI equipment. The sensor is based on the company's experience in developing miniaturized circuitry for space telemetry and other spacecraft electrical systems; this experience enabled SCI to package interruptor circuitry in the extremely limited space available and to produce sensory devices at practicable cost. The tiny sensor measures the strength of the electrical current and detects current differentials that indicate a fault in the functioning of an electrical system. The sensing element then triggers a signal to a disconnect mechanism in the GFI, which cuts off the current in the faulty circuit.

  1. Rate type isotach compaction of consolidated sandstone

    NARCIS (Netherlands)

    Waal, J.A. de; Thienen-Visser, K. van; Pruiksma, J.P.

    2015-01-01

    Laboratory experiments on samples from a consolidated sandstone reservoir are presented that demonstrate rate type compaction behaviour similar to that observed on unconsolidated sands and soils. Such rate type behaviour can have large consequences for reservoir compaction, surface subsidence and

  2. Control of quasi-monoenergetic electron beams from laser-plasma accelerators with adjustable shock density profile

    Science.gov (United States)

    Tsai, Hai-En; Swanson, Kelly K.; Barber, Sam K.; Lehe, Remi; Mao, Hann-Shin; Mittelberger, Daniel E.; Steinke, Sven; Nakamura, Kei; van Tilborg, Jeroen; Schroeder, Carl; Esarey, Eric; Geddes, Cameron G. R.; Leemans, Wim

    2018-04-01

    The injection physics in a shock-induced density down-ramp injector was characterized, demonstrating precise control of a laser-plasma accelerator (LPA). Using a jet-blade assembly, experiments systematically varied the shock injector profile, including shock angle, shock position, up-ramp width, and acceleration length. Our work demonstrates that beam energy, energy spread, and pointing can be controlled by adjusting these parameters. As a result, an electron beam that was highly tunable from 25 to 300 MeV with 8% energy spread (ΔEFWHM/E), 1.5 mrad divergence, and 0.35 mrad pointing fluctuation was produced. Particle-in-cell simulation characterized how variation in the shock angle and up-ramp width impacted the injection process. This highly controllable LPA represents a suitable, compact electron beam source for LPA applications such as Thomson sources and free-electron lasers.

  3. 29th International Symposium on Shock Waves

    CERN Document Server

    Ranjan, Devesh

    2015-01-01

    This proceedings present the results of the 29th International Symposium on Shock Waves (ISSW29) which was held in Madison, Wisconsin, U.S.A., from July 14 to July 19, 2013. It was organized by the Wisconsin Shock Tube Laboratory, which is part of the College of Engineering of the University of Wisconsin-Madison. The ISSW29 focused on the following areas: Blast Waves, Chemically Reactive Flows, Detonation and Combustion,  Facilities, Flow Visualization, Hypersonic Flow, Ignition, Impact and Compaction, Industrial Applications, Magnetohydrodynamics, Medical and Biological Applications, Nozzle Flow, Numerical Methods, Plasmas, Propulsion, Richtmyer-Meshkov Instability, Shock-Boundary Layer Interaction, Shock Propagation and Reflection, Shock Vortex Interaction, Shock Waves in Condensed Matter, Shock Waves in Multiphase Flow, as well as Shock Waves in Rarefield Flow. The two Volumes contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 29 and individuals interes...

  4. Study of phase transitions in cerium in shock-wave experiments

    Directory of Open Access Journals (Sweden)

    Zhernokletov M.V.

    2015-01-01

    Full Text Available Cerium has a complex phase diagram that is explained by the presence of structure phase transitions. Planar gauges were used in various combinations in experiments for determination of sound velocity dependence on pressure in cerium by the technique of PVDF gauge. The data of time dependence on pressure profiles with use of x(t diagrams and the D(u relation for cerium allowed the definition of the Lagrangian velocity of the unloading wave CLagr and the Eulerian velocity CEul by taking into account the compression σ. These results accords with data obtained by using the technique of VISAR and a manganin-based gauge, and calculated pressure dependence of isentropic sound velocity according to the VNIITF EOS. Metallography analysis of post-experimental samples did not find any changes in a phase composition.

  5. Shock-to-detonation transition of RDX, HMX and NTO based composite high explosives: experiments and modelling

    International Nuclear Information System (INIS)

    Baudin, G; Roudot, M; Genetier, M; Mateille, P; Lefrançois, A

    2014-01-01

    HMX, RDX and NTO based cast-cured plastic bounded explosive (PBX) are widely used in insensitive ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside PBX. Comparing to a pressed PBX, a cast-cured PBX is not porous and the hot-spots are mainly located at the grain-binder interface leading to a different burning behavior during shock-to-detonation transition. Here, we review the shock-to-detonation transition (SDT) and its modeling for cast-cured PBX containing HMX, RDX and NTO. Future direction is given in conclusion.

  6. Shock-to-detonation transition of RDX, HMX and NTO based composite high explosives: experiments and modelling

    Science.gov (United States)

    Baudin, G.; Roudot, M.; Genetier, M.; Mateille, P.; Lefrançois, A.

    2014-05-01

    HMX, RDX and NTO based cast-cured plastic bounded explosive (PBX) are widely used in insensitive ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside PBX. Comparing to a pressed PBX, a cast-cured PBX is not porous and the hot-spots are mainly located at the grain-binder interface leading to a different burning behavior during shock-to-detonation transition. Here, we review the shock-to-detonation transition (SDT) and its modeling for cast-cured PBX containing HMX, RDX and NTO. Future direction is given in conclusion.

  7. Compact NMR

    Energy Technology Data Exchange (ETDEWEB)

    Bluemich, Bernhard; Haber-Pohlmeier, Sabina; Zia, Wasif [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMC)

    2014-06-01

    Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.

  8. Compact vortices

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Losano, L.; Marques, M.A.; Zafalan, I. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil); Menezes, R. [Universidade Federal da Paraiba, Departamento de Ciencias Exatas, Rio Tinto, PB (Brazil); Universidade Federal de Campina Grande, Departamento de Fisica, Campina Grande, PB (Brazil)

    2017-02-15

    We study a family of Maxwell-Higgs models, described by the inclusion of a function of the scalar field that represent generalized magnetic permeability. We search for vortex configurations which obey first-order differential equations that solve the equations of motion. We first deal with the asymptotic behavior of the field configurations, and then implement a numerical study of the solutions, the energy density and the magnetic field. We work with the generalized permeability having distinct profiles, giving rise to new models, and we investigate how the vortices behave, compared with the solutions of the corresponding standard models. In particular, we show how to build compact vortices, that is, vortex solutions with the energy density and magnetic field vanishing outside a compact region of the plane. (orig.)

  9. Response Of Lowland Rice To Soil Compaction

    International Nuclear Information System (INIS)

    Idawati; Haryanto

    2000-01-01

    Soil compaction, as a new tillage practice for paddy soil, is to substitute pudding in order to reduce land preparation cost. To study response of lowland rice to soil compaction, a pot experiment has been conducted which took place in the greenhouse of P3TIR-BATAN. Soil for experiment was taken from pusakanegara. Two factors (degree of soil compaction and rice variety) were combined. Degree of compaction was split into 3 levels (DI = normal; D215% more compact than normal; 30 % more compact than normal), and rice variety into 2 levels (IR64 and Atomita IV). KH 2 32 PO 4 solution was injected into the soil surrounding rice clump to test the root activity at blooming stage of rice plant. Data resulted from this experiment is presented together with additional data from some other experiments of fertilization in the research s erie to study soil compaction. Some information's from experiment results are as following. Both rice varieties tested gave the same response to soil compaction. Root activity, according to data of 32 P absorbed by plant, was not harmed by soil compaction at the degree tested in the experiment. This prediction is supported by the growth by rice observed at generative growth stage, in pot experiment as well as in field experiment, which showed that soil compaction tested did not decrease rice yield but in opposite in tended to increase the yield. In practising soil compaction in land preparation, fertilizers should be applied by deep placement to have higher increasing is rice yield

  10. Compaction of cereal grain

    OpenAIRE

    Wychowaniec, J.; Griffiths, I.; Gay, A.; Mughal, A.

    2013-01-01

    We report on simple shaking experiments to measure the compaction of a column of Firth oat grain. Such grains are elongated anisotropic particles with a bimodal polydispersity. In these experiments, the particle configurations start from an initially disordered, low-packing-fraction state and under vertical shaking evolve to a dense state with evidence of nematic-like structure at the surface of the confining tube. This is accompanied by an increase in the packing fraction of the grain.

  11. Compact stars

    Science.gov (United States)

    Estevez-Delgado, Gabino; Estevez-Delgado, Joaquin

    2018-05-01

    An analysis and construction is presented for a stellar model characterized by two parameters (w, n) associated with the compactness ratio and anisotropy, respectively. The reliability range for the parameter w ≤ 1.97981225149 corresponds with a compactness ratio u ≤ 0.2644959374, the density and pressures are positive, regular and monotonic decrescent functions, the radial and tangential speed of sound are lower than the light speed, moreover, than the plausible stability. The behavior of the speeds of sound are determinate for the anisotropy parameter n, admitting a subinterval where the speeds are monotonic crescent functions and other where we have monotonic decrescent functions for the same speeds, both cases describing a compact object that is also potentially stable. In the bigger value for the observational mass M = 2.05 M⊙ and radii R = 12.957 Km for the star PSR J0348+0432, the model indicates that the maximum central density ρc = 1.283820319 × 1018 Kg/m3 corresponds to the maximum value of the anisotropy parameter and the radial and tangential speed of the sound are monotonic decrescent functions.

  12. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    Science.gov (United States)

    Robey, H. F.; Munro, D. H.; Spears, B. K.; Marinak, M. M.; Jones, O. S.; Patel, M. V.; Haan, S. W.; Salmonson, J. D.; Landen, O. L.; Boehly, T. R.; Nikroo, A.

    2008-05-01

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum.

  13. Investigation of 3D Shock-Boundary Layer Interaction: A Combined Approach using Experiments, Numerical Simulations and Stability Analysis

    Science.gov (United States)

    2015-12-02

    layer , the non-reflecting boundary condition suggested by Poinsot and Lele is adopted.38 On the flat – plate surface, the no-penetration (v = 0) and the no...Introduction Shock-wave boundary layer interactions (SBLIs) occur in most supersonic flight applications and have been the subject of many studies...generator plate is emulated to create an oblique shock that impinges on the boundary layer causing separation. This is similar to the experimental

  14. Numerical results from a study of LiH: the proposed standard material for the high pressure shock experiment

    International Nuclear Information System (INIS)

    Rogers, F.J.

    1975-01-01

    It is proposed to send a high pressure shock wave through a layer of LiH and then into a sample of high Z-material, resulting in a reflected shock wave back into the LiH. If the Hugoniot and some reflected Hugoniots for LiH are known the EOS of the sample can be obtained from the ''impedance matching method.'' The theory and its range of validity are described

  15. Shock compression of geological materials

    International Nuclear Information System (INIS)

    Kirk, S; Braithwaite, C; Williamson, D; Jardine, A

    2014-01-01

    Understanding the shock compression of geological materials is important for many applications, and is particularly important to the mining industry. During blast mining the response to shock loading determines the wave propagation speed and resulting fragmentation of the rock. The present work has studied the Hugoniot of two geological materials; Lake Quarry Granite and Gosford Sandstone. For samples of these materials, the composition was characterised in detail. The Hugoniot of Lake Quarry Granite was predicted from this information as the material is fully dense and was found to be in good agreement with the measured Hugoniot. Gosford Sandstone is porous and undergoes compaction during shock loading. Such behaviour is similar to other granular material and we show how it can be described using a P-a compaction model.

  16. Shock wave interaction with turbulence: Pseudospectral simulations

    International Nuclear Information System (INIS)

    Buckingham, A.C.

    1986-01-01

    Shock waves amplify pre-existing turbulence. Shock tube and shock wave boundary layer interaction experiments provide qualitative confirmation. However, shock pressure, temperature, and rapid transit complicate direct measurement. Computational simulations supplement the experimental data base and help isolate the mechanisms responsible. Simulations and experiments, particularly under reflected shock wave conditions, significantly influence material mixing. In these pseudospectral Navier-Stokes simulations the shock wave is treated as either a moving (tracked or fitted) domain boundary. The simulations assist development of code mix models. Shock Mach number and pre-existing turbulence intensity initially emerge as key parameters. 20 refs., 8 figs

  17. Influence Of The Gripping Fixture On The Modified Compact Tension Test Results: Evaluation Of The Experiments On Cylindrical Concrete Specimens

    Directory of Open Access Journals (Sweden)

    Holušová Táňa

    2015-12-01

    Full Text Available The modified compact tension test (MCT might become in the future a stable test configuration for the evaluation of fracture-mechanics parameters or also for description of fatigue behavior of composites materials such as concrete. Core drilling is used for sampling of existing structures. These samples have cylindrical shape with the selected thickness to avoid the stress concentration. This contribution focuses on the evaluation of the fracture behavior during static and quasi static tests. Static tests are performed on standard specimen with diameter 150 mm and length 300 mm. The quasi-static tests are performed using two different gripping fixtures. The results for quasi-static tests are represented as L-COD diagrams (i.e. load vs. crack opening displacement measured on the loading axis. The comparison of results and discussion of advantages and disadvantages are introduced.

  18. Early time implosion symmetry from two-axis shock-timing measurements on indirect drive NIF experiments

    Energy Technology Data Exchange (ETDEWEB)

    Moody, J. D., E-mail: moody4@llnl.gov; Robey, H. F.; Celliers, P. M.; Munro, D. H.; Barker, D. A.; Baker, K. L.; Döppner, T.; Hash, N. L.; Berzak Hopkins, L.; LaFortune, K.; Landen, O. L.; LePape, S.; MacGowan, B. J.; Ralph, J. E.; Ross, J. S.; Widmayer, C. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Nikroo, A.; Giraldez, E. [General Atomics, San Diego, California 92186-5608 (United States); Boehly, T. [Laboratory for Laser Energetics, Rochester, New York 14623-1299 (United States)

    2014-09-15

    An innovative technique has been developed and used to measure the shock propagation speed along two orthogonal axes in an inertial confinement fusion indirect drive implosion target. This development builds on an existing target and diagnostic platform for measuring the shock propagation along a single axis. A 0.4 mm square aluminum mirror is installed in the ablator capsule which adds a second orthogonal view of the x-ray-driven shock speeds. The new technique adds capability for symmetry control along two directions of the shocks launched in the ablator by the laser-generated hohlraum x-ray flux. Laser power adjustments in four different azimuthal cones based on the results of this measurement can reduce time-dependent symmetry swings during the implosion. Analysis of a large data set provides experimental sensitivities of the shock parameters to the overall laser delivery and in some cases shows the effects of laser asymmetries on the pole and equator shock measurements.

  19. Experiment Study on Elastic Indicator of Thermal Shock Ceramic Materials——Implementation of Students’ Innovative Research Project of Shandong University of Science and Technology

    Directory of Open Access Journals (Sweden)

    Wang Yanxia

    2017-01-01

    Full Text Available In order to improve the quality of undergraduate education and combine theory and practice, Shandong University of science and technology organized innovative research activities project for undergraduates. Combined with the characteristics of engineering mechanics course, teachers of engineering mechanics teaching and research section guided students to take an active part in scientific research and innovation practice teaching, which has obtained a good teaching effect. This paper introduces the concrete implement process of the college students’ innovative scientific research project “Experiment Study on Elastic Indicator of Thermal Shock Ceramic Materials”, which measures elastic indicator of ceramics using the ultrasonic method. This paper studies elastic indicator change rule of the mullite ceramic samples under different factors such as temperature difference, thermal shock times and so on. Studies have shown that in the condition of air-cooling, with the increase of thermal shock temperature difference and thermal shock times, the elastic modulus value, shear modulus and Poisson’s ratio are in a falling trend. The project implementation have proved that implement undergraduate innovation research projects could effectively arouse students’ learning enthusiasm, cultivate students’ scientific research innovation and analytical abilities to solve practical scientific research problems.

  20. The Evolution of the Control System for the Electromagnetic Calorimeter of the Compact Muon Solenoid Experiment at the Large Hadron Collider

    CERN Multimedia

    Holme, Oliver; Dissertori, Günther; Lustermann, Werner; Zelepoukine, Serguei

    2011-01-01

    This paper discusses the evolution of the Detector Control System (DCS) designed and implemented for the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) as well as the operational experience acquired during the LHC physics data taking periods of 2010 and 2011. The current implementation in terms of functionality and planned hardware upgrades are presented. Furthermore, a project for reducing the long-term software maintenance, including a year-long detailed analysis of the existing applications, is put forward and the current outcomes which have informed the design decisions for the next CMS ECAL DCS software generation are described. The main goals for the new version are to minimize external dependencies enabling smooth migration to new hardware and software platforms and to maintain the existing functionality whilst substantially reducing support and maintenance effort through homogenization, simplification and standardization of the contr...

  1. Design and initial operation of a two-color soft x-ray camera system on the Compact Toroidal Hybrid experiment

    International Nuclear Information System (INIS)

    Herfindal, J. L.; Dawson, J. D.; Ennis, D. A.; Hartwell, G. J.; Loch, S. D.; Maurer, D. A.

    2014-01-01

    A multi-camera soft x-ray diagnostic has been developed to measure the equilibrium electron temperature profile and temperature fluctuations due to magnetohydrodynamic activity on the Compact Toroidal Hybrid experiment. The diagnostic consists of three separate cameras each employing two 20-channel diode arrays that view the same plasma region through different beryllium filter thicknesses of 1.8 μm and 3.0 μm allowing electron temperature measurements between 50 eV and 200 eV. The Compact Toroidal Hybrid is a five-field period current-carrying stellarator, in which the presence of plasma current strongly modifies the rotational transform and degree of asymmetry of the equilibrium. Details of the soft x-ray emission, effects of plasma asymmetry, and impurity line radiation on the design and measurement of the two-color diagnostic are discussed. Preliminary estimates of the temperature perturbation due to sawtooth oscillations observed in these hybrid discharges are given

  2. Acceleration mechanisms flares, magnetic reconnection and shock waves

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1979-01-01

    Several mechanisms are briefly discussed for the acceleration of particles in the astrophysical environment. Included are hydrodynamic acceleration, spherically convergent shocks, shock and a density gradient, coherent electromagnetic acceleration, the flux tube origin, symmetries and instabilities, reconnection, galactic flares, intergalactic acceleration, stochastic acceleration, and astrophysical shocks. It is noted that the supernova shock wave models still depend critically on the presupernova star structure and the assumption of highly compact presupernova models for type I supernovae. 37 references

  3. Shock Dynamics in Stellar Outbursts. I. Shock Formation

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Stephen; Matzner, Christopher D., E-mail: ro@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)

    2017-05-20

    Wave-driven outflows and non-disruptive explosions have been implicated in pre-supernova outbursts, supernova impostors, luminous blue variable eruptions, and some narrow-line and superluminous supernovae. To model these events, we investigate the dynamics of stars set in motion by strong acoustic pulses and wave trains, focusing on nonlinear wave propagation, shock formation, and an early phase of the development of a weak shock. We identify the shock formation radius, showing that a heuristic estimate based on crossing characteristics matches an exact expansion around the wave front and verifying both with numerical experiments. Our general analytical condition for shock formation applies to one-dimensional motions within any static environment, including both eruptions and implosions. We also consider the early phase of shock energy dissipation. We find that waves of super-Eddington acoustic luminosity always create shocks, rather than damping by radiative diffusion. Therefore, shock formation is integral to super-Eddington outbursts.

  4. Effects of SF$_{6}$ on the avalanche mode operation of a real-sized double-gap resistive plate chamber for the Compact Muon Solenoid experiment

    CERN Document Server

    Ahn Sung Hwan; Hong, B; Hong, S J; Ito, M; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee, H W; Lee, K B; Lee, K S; Lee, S J; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee, J T; Ryu, M S; Shim, H H; Sim, K S; Kang, T I

    2005-01-01

    We present the design and the test, results for a real-sized prototype resistive plate chamber by using cosmic-ray muons for the forward region of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). In particular, we investigate the effects of adding SF/sub 6/ to the gas mixture for the avalanche mode operation of a resistive plate chamber. A small fraction of SF/sub 6/ is very effective in suppressing streamer signals in a resistive plate chamber. The shapes of the muon detection efficiency and the muon cluster size remain similar, but are shifted to higher operating voltage by SF/sub 6/. The noise cluster rate and size are not influenced by SF/sub 6/.

  5. Experimental and theoretical investigations of shock-induced flow of reactive porous media

    Energy Technology Data Exchange (ETDEWEB)

    Baer, M.R.; Graham, R.A.; Anderson, M.U. [Sandia National Labs., Albuquerque, NM (United States); Sheffield, S.A.; Gustavsen, R.L. [Los Alamos National Lab., NM (United States)

    1996-11-01

    In this work, the microscale processes of consolidation, deformation and reaction features of shocked porous materials are studied. Time- resolve particle velocities and stress fields associated with dispersive compaction waves are measured in gas-gun experiments. In these tests, a thin porous layer of HMX is shock-loaded at varied levels. At high impact, significant reaction is triggered by the rapid material distortion during compaction. In parallel modeling studies, continuum mixture theory is applied to describe the behavior of averaged wave-fields in heterogeneous media. One-dimensional simulations of gas-gun experiments demonstrate that the wave features and interactions with viscoelastic materials in the gauge package are well described by mixture theory, including reflected wave behavior and conditions where significant reaction is initiated. Numerical simulations of impact on a collection of discrete HMX `crystals` are also presented using shock physics analysis. Three-dimensional simulations indicate that rapid distortion occurs at material contact points; the nature of the dispersive fields includes large amplitude fluctuations of stress with wavelengths of several particle diameters. Localization of energy causes `hot-spots` due to shock focusing and plastic work as material flows into interstitial regions. These numerical experiments demonstrate that `hot-spots` are strongly influenced by multiple crystal interactions. This mesoscale study provides new insights into micromechanical behavior of heterogeneous energetic materials.

  6. CMS (Compact Muon Solenoid)

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The milestone workshops on LHC experiments in Aachen in 1990 and at Evian in 1992 provided the first sketches of how LHC detectors might look. The concept of a compact general-purpose LHC experiment based on a solenoid to provide the magnetic field was first discussed at Aachen, and the formal Expression of Interest was aired at Evian. It was here that the Compact Muon Solenoid (CMS) name first became public. Optimizing first the muon detection system is a natural starting point for a high luminosity (interaction rate) proton-proton collider experiment. The compact CMS design called for a strong magnetic field, of some 4 Tesla, using a superconducting solenoid, originally about 14 metres long and 6 metres bore. (By LHC standards, this warrants the adjective 'compact'.) The main design goals of CMS are: 1 - a very good muon system providing many possibilities for momentum measurement (physicists call this a 'highly redundant' system); 2 - the best possible electromagnetic calorimeter consistent with the above; 3 - high quality central tracking to achieve both the above; and 4 - an affordable detector. Overall, CMS aims to detect cleanly the diverse signatures of new physics by identifying and precisely measuring muons, electrons and photons over a large energy range at very high collision rates, while also exploiting the lower luminosity initial running. As well as proton-proton collisions, CMS will also be able to look at the muons emerging from LHC heavy ion beam collisions. The Evian CMS conceptual design foresaw the full calorimetry inside the solenoid, with emphasis on precision electromagnetic calorimetry for picking up photons. (A light Higgs particle will probably be seen via its decay into photon pairs.) The muon system now foresaw four stations. Inner tracking would use silicon microstrips and microstrip gas chambers, with over 10 7 channels offering high track finding efficiency. In the central CMS barrel, the tracking elements are

  7. Shock diffraction in alumina powder

    International Nuclear Information System (INIS)

    Venz, G.; Killen, P.D.; Page, N.W.

    1996-01-01

    In order to produce complex shaped components by dynamic compaction of ceramic powders detailed knowledge of their response under shock loading conditions is required. This work attempts to provide data on release effects and shock attenuation in 1 μm and 5 μm α-alumina powders which were compacted to between 85 % and 95 % of the solid phase density by the impact of high velocity steel projectiles. As in previous work, the powder was loaded into large cylindrical dies with horizontal marker layers of a contrasting coloured powder to provide a record of powder displacement in the recovered specimens. After recovery and infiltration with a thermosetting resin the specimens were sectioned and polished to reveal the structure formed by the passage of the projectile and shock wave. Results indicate that the shock pressures generated were of the order of 0.5 to 1.4 GPa and higher, with shock velocities and sound speeds in the ranges 650 to 800 m/s and 350 to 400 m/s respectively

  8. Shock absorber

    International Nuclear Information System (INIS)

    Nemeth, J.D.

    1981-01-01

    A shock absorber for the support of piping and components in a nuclear power plant is described. It combines a high degree of stiffness under sudden shocks, e.g. seismic disturbances, with the ability to allow for thermal expansion without resistance when so required. (JIW)

  9. Localized atomic segregation in the spalled area of a Zr50Cu40Al10 bulk metallic glasses induced by laser-shock experiment

    Science.gov (United States)

    Jodar, B.; Loison, D.; Yokoyama, Y.; Lescoute, E.; Nivard, M.; Berthe, L.; Sangleboeuf, J.-C.

    2018-02-01

    Laser-shock experiments were performed on a ternary {Zr50{Cu}40{Al}10} bulk metallic glass. A spalling process was studied through post-mortem analyses conducted on a recovered sample and spall. Scanning electron microscopy magnification of fracture surfaces revealed the presence of a peculiar feature known as cup-cone. Cups are found on sample fracture surface while cones are observed on spall. Two distinct regions can be observed on cups and cones: a smooth viscous-like region in the center and a flat one with large vein-pattern in the periphery. Energy dispersive spectroscopy measurements conducted on these features emphasized atomic distribution discrepancies both on the sample and spall. We propose a mechanism for the initiation and the growth of these features but also a process for atomic segregation during spallation. Cup and cones would originate from cracks arising from shear bands formation (softened paths). These shear bands result from a quadrupolar-shaped atomic disorder engendered around an initiation site by shock wave propagation. This disorder turns into a shear band when tensile front reaches spallation plane. During the separation process, temperature gain induced by shock waves and shear bands generation decreases material viscosity leading to higher atomic mobility. Once in a liquid-like form, atomic clusters migrate and segregate due to inertial effects originating from particle velocity variation (interaction of release waves). As a result, a high rate of copper is found in sample cups and high zirconium concentration is found on spall cones.

  10. Compact torsatron reactors

    International Nuclear Information System (INIS)

    Lyon, J.F.; Carreras, B.A.; Lynch, V.E.; Tolliver, J.S.; Sviatoslavsky, I.N.

    1988-05-01

    Low-aspect-ratio torsatron configurations could lead to compact stellarator reactors with R 0 = 8--11m, roughly one-half to one-third the size of more conventional stellarator reactor designs. Minimum-size torsatron reactors are found using various assumptions. Their size is relatively insensitive to the choice of the conductor parameters and depends mostly on geometrical constraints. The smallest size is obtained by eliminating the tritium breeding blanket under the helical winding on the inboard side and by reducing the radial depth of the superconducting coil. Engineering design issues and reactor performance are examined for three examples to illustrate the feasibility of this approach for compact reactors and for a medium-size (R 0 ≅ 4 m,/bar a/ /approx lt/ 1 m) copper-coil ignition experiment. 26 refs., 11 figs., 7 tabs

  11. Validation of the ABBN/CONSYST constants system. Part 1: Validation through the critical experiments on compact metallic cores

    International Nuclear Information System (INIS)

    Ivanova, T.T.; Manturov, G.N.; Nikolaev, M.N.; Rozhikhin, E.V.; Semenov, M.Yu.; Tsiboulia, A.M.

    1999-01-01

    Worldwide compilation of criticality safety benchmark experiments, evaluated due to an activity of the International Criticality Safety Benchmark Evaluation Project (ICSBEP), discovers new possibilities for validation of the ABBN-93.1 cross section library for criticality safety analysis. Results of calculations of small assemblies with metal-fuelled cores are presented in this paper. It is concluded that ABBN-93.1 predicts criticality of such systems with required accuracy

  12. Study of compact X-ray laser pumped by pulse-train laser. Double-target experiment

    International Nuclear Information System (INIS)

    Yamaguchi, Naohiro; Fujikawa, Chiemi; Hara, Tamio

    2000-01-01

    We have been developing a tabletop x-ray laser based on the recombination plasma scheme. An advanced experiment has been started to improve x-ray laser output substantially. Two 11-mm-long laser produced plasmas were produced so that their axis aligned into a line, the double-target configuration. X-ray intensity of the 15.47 nm transition line of the Li-like Al ion has been enhanced in the double-target configuration. (author)

  13. Utility of compact ultrasound in a mass surgical selection program in Africa: experience of a sonologist at the MV Africa Mercy Hospital Ship's screening day.

    Science.gov (United States)

    Harris, Robert D; Parker, Gary

    2015-02-01

    Compact ultrasound (US) was introduced in an austere setting with no other available imaging for an annual mass surgical screening day. Compact US examinations were performed on 25 patients from more than 7000 potential patients, as deemed possibly useful by the screening surgeons. Of the 20 patients with recorded data, compact US was helpful in 14 of 20 as a decision-making tool, obviating computed tomography for preoperative planning. Compact US was helpful in most cases, saving resources (computed tomography), technologist time, and radiation risk in this select population. © 2015 by the American Institute of Ultrasound in Medicine.

  14. demystifying the shock of shocking

    African Journals Online (AJOL)

    (with a pulse), atrial fibrillation and atrial flutter. The energy dose in cardioversion is less (0.5. - 2 J/kg) than in defibrillation (2 - 4 J/kg). In cardioversion the shock is discharged synchronously with the native R wave of the patient. Without synchronisation,. VF can be induced if a shock is delivered during the refractory period ...

  15. CFD Validation Experiment of a Mach 2.5 Axisymmetric Shock-Wave Boundary-Layer Interaction

    Science.gov (United States)

    Davis, David O.

    2015-01-01

    Preliminary results of an experimental investigation of a Mach 2.5 two-dimensional axisymmetric shock-wave/boundary-layer interaction (SWBLI) are presented. The purpose of the investigation is to create a SWBLI dataset specifically for CFD validation purposes. Presented herein are the details of the facility and preliminary measurements characterizing the facility and interaction region. The results will serve to define the region of interest where more detailed mean and turbulence measurements will be made.

  16. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    ... through the compaction formulation process and application. Compaction of powder constituents both active ingredient and excipients is examined to ensure consistent and reproducible disintegration and dispersion profiles...

  17. High Pressure In Situ X-ray Diffraction Study of MnO to 120 GPa and Comparison with Shock Compression Experiment

    Science.gov (United States)

    Yagi, Takehiko; Kondo, Tadashi; Syono, Yasuhiko

    1997-07-01

    In order to clarify the nature of the phase transformation in MnO observed at around 90 GPa by shock compression experiment (Syono et al., this symposium), high pressure in situ x-ray experiments were carried out up to 120 GPa. Powdered sample was directly compressed in Mao-Bell type diamond anvil and x-ray experiments were carried out using angle dispersive technique by combining synchrotron radiation and imaging plate detector. Distortion of the B1 structured phase into hexagonal unit cell was observed from 25-40 GPa, which continues to increase up to 90 GPa. At around 90 GPa, discontinuous change of the diffraction was observed. This new phase cannot be explained by a simple B2 structure and the analysis of this phase is in progress. This high pressure phase has metallic appearance, which reverses to transparent MnO on release of pressure.

  18. Energy-harvesting shock absorber with a mechanical motion rectifier

    Science.gov (United States)

    Li, Zhongjie; Zuo, Lei; Kuang, Jian; Luhrs, George

    2013-02-01

    Energy-harvesting shock absorbers are able to recover the energy otherwise dissipated in the suspension vibration while simultaneously suppressing the vibration induced by road roughness. They can work as a controllable damper as well as an energy generator. An innovative design of regenerative shock absorbers is proposed in this paper, with the advantage of significantly improving the energy harvesting efficiency and reducing the impact forces caused by oscillation. The key component is a unique motion mechanism, which we called ‘mechanical motion rectifier (MMR)’, to convert the oscillatory vibration into unidirectional rotation of the generator. An implementation of a MMR-based harvester with high compactness is introduced and prototyped. A dynamic model is created to analyze the general properties of the motion rectifier by making an analogy between mechanical systems and electrical circuits. The model is capable of analyzing electrical and mechanical components at the same time. Both simulation and experiments are carried out to verify the modeling and the advantages. The prototype achieved over 60% efficiency at high frequency, much better than conventional regenerative shock absorbers in oscillatory motion. Furthermore, road tests are done to demonstrate the feasibility of the MMR shock absorber, in which more than 15 Watts of electricity is harvested while driving at 15 mph on a smooth paved road. The MMR-based design can also be used for other applications of vibration energy harvesting, such as from tall buildings or long bridges.

  19. Energy-harvesting shock absorber with a mechanical motion rectifier

    International Nuclear Information System (INIS)

    Li, Zhongjie; Zuo, Lei; Kuang, Jian; Luhrs, George

    2013-01-01

    Energy-harvesting shock absorbers are able to recover the energy otherwise dissipated in the suspension vibration while simultaneously suppressing the vibration induced by road roughness. They can work as a controllable damper as well as an energy generator. An innovative design of regenerative shock absorbers is proposed in this paper, with the advantage of significantly improving the energy harvesting efficiency and reducing the impact forces caused by oscillation. The key component is a unique motion mechanism, which we called ‘mechanical motion rectifier (MMR)’, to convert the oscillatory vibration into unidirectional rotation of the generator. An implementation of a MMR-based harvester with high compactness is introduced and prototyped. A dynamic model is created to analyze the general properties of the motion rectifier by making an analogy between mechanical systems and electrical circuits. The model is capable of analyzing electrical and mechanical components at the same time. Both simulation and experiments are carried out to verify the modeling and the advantages. The prototype achieved over 60% efficiency at high frequency, much better than conventional regenerative shock absorbers in oscillatory motion. Furthermore, road tests are done to demonstrate the feasibility of the MMR shock absorber, in which more than 15 Watts of electricity is harvested while driving at 15 mph on a smooth paved road. The MMR-based design can also be used for other applications of vibration energy harvesting, such as from tall buildings or long bridges. (paper)

  20. Shock compression of diamond crystal

    OpenAIRE

    Kondo, Ken-ichi; Ahrens, Thomas J.

    1983-01-01

    Two shock wave experiments employing inclined mirrors have been carried out to determine the Hugoniot elastic limit (HEL), final shock state at 191 and 217 GPa, and the post-shock state of diamond crystal, which is shock-compressed along the intermediate direction between the and crystallographic axes. The HEL wave has a velocity of 19.9 ± 0.3 mm/µsec and an amplitude of 63 ± 28 GPa. An alternate interpretation of the inclined wedge mirror streak record suggests a ramp precursor wave and th...

  1. Hypovolemic shock

    Science.gov (United States)

    ... the person's position unless they are in immediate danger. Do not give fluids by mouth. If person ... the patient with shock. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: ...

  2. Shock absorber

    International Nuclear Information System (INIS)

    Housman, J.J.

    1978-01-01

    A shock absorber is described for use in a hostile environment at the end of a blind passage for absorbing impact loads. The shock absorber includes at least one element which occupies the passage and which is comprised of a porous brittle material which is substantially non-degradable in the hostile environment. A void volume is provided in the element to enable the element to absorb a predetermined level of energy upon being crushed due to impact loading

  3. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. II. Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Golubev, P.; Avdeichikov, V.; Carlen, L.; Jakobsson, B. E-mail: bo.jakobsson@kosufy.lu.se; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J

    2003-03-11

    We describe the detectors for identification of charged particles and fragments in CHICSi, a large solid angle multi-telescope system mounted inside an ultra-high vacuum (UHV), cluster-jet target chamber. CHICSi performs nuclear reaction experiments at storage rings. The telescopes consist of a first very thin, 10-14 {mu}m Si detector, a second 300 {mu}m (or possibly 500 {mu}m) ion implanted Si detector supplemented by a 6 mm GSO(Ce) scintillator read out by a photodiode (PD) or by a third 300 {mu}m Si detector. The telescopes provide full charge separation up to Z=17 and mass resolution up to A=9 in the energy range 0.7-60A MeV. The thin p-i-n diode detector, etched out from a 280 {mu}m Si wafer, and the GSO/PD detector, both exclusively developed for CHICSi, provide an energy resolution {<=}8%, while the standard 300 {mu}m detectors have {<=}2% energy resolution. Radiation stability of the Si detectors is confirmed up to an integrated flux of 10{sup 10} alpha particles. The GSO detector has 70% light collection efficiency with the optical coupling to the PD a simple open, 0.2 mm, gap. A new method, developed to perform absolute energy calibration for the GSO/PD detector is presented.

  4. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. II. Detectors

    International Nuclear Information System (INIS)

    Golubev, P.; Avdeichikov, V.; Carlen, L.; Jakobsson, B.; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J.

    2003-01-01

    We describe the detectors for identification of charged particles and fragments in CHICSi, a large solid angle multi-telescope system mounted inside an ultra-high vacuum (UHV), cluster-jet target chamber. CHICSi performs nuclear reaction experiments at storage rings. The telescopes consist of a first very thin, 10-14 μm Si detector, a second 300 μm (or possibly 500 μm) ion implanted Si detector supplemented by a 6 mm GSO(Ce) scintillator read out by a photodiode (PD) or by a third 300 μm Si detector. The telescopes provide full charge separation up to Z=17 and mass resolution up to A=9 in the energy range 0.7-60A MeV. The thin p-i-n diode detector, etched out from a 280 μm Si wafer, and the GSO/PD detector, both exclusively developed for CHICSi, provide an energy resolution ≤8%, while the standard 300 μm detectors have ≤2% energy resolution. Radiation stability of the Si detectors is confirmed up to an integrated flux of 10 10 alpha particles. The GSO detector has 70% light collection efficiency with the optical coupling to the PD a simple open, 0.2 mm, gap. A new method, developed to perform absolute energy calibration for the GSO/PD detector is presented

  5. Diverse Formation Mechanisms for Compact Galaxies

    Science.gov (United States)

    Kim, Jin-Ah; Paudel, Sanjaya; Yoon, Suk-Jin

    2018-01-01

    Compact, quenched galaxies such as M32 are unusual ones located off the mass - size scaling relation defined by normal galaxies. Still, their formation mechanisms remain unsolved. Here we investigate the evolution of ~100 compact, quenched galaxies at z = 0 identified in the Illustris cosmological simulation. We identify three ways for a galaxy to become a compact one and, often, multiple mechanisms operate in a combined manner. First, stripping is responsible for making about a third of compact galaxies. Stripping removes stars from galaxies, usually while keeping their sizes intact. About one third are galaxies that cease their growth early on after entering into more massive, gigantic halos. Finally, about half of compact galaxies, ~ 35 % of which turn out to undergo stripping, experience the compaction due to the highly centrally concentrated star formation. We discuss the evolutionary path of compact galaxies on the mass – size plane for each mechanism in a broader context of dwarf galaxy formation and evolution.

  6. Reconstruction of missing transverse energy and prospect of searching for Higgs boson produced via vector boson fusion in Compact Muon Solenoid experiment

    CERN Document Server

    Pi, Haifeng

    2005-01-01

    We performed full detector simulation studies of missing transverse energy (Emiss T ) reconstruction and correction, and the prospects for searching for a low mass Higgs Boson (120 < mH < 250 GeV/c 2 ) produced via the vector boson fusion (VBF) process through the decay of H → W+W− → `νjj at Compact Muon Solenoid (CMS) experiment in Large Hadron Collider (LHC). We developed a new jet energy correction algorithm by parameterizing the jet energy distribution around the jet axis. The jet energy resolution is improved by calibrating the jet energy scale and by reducing the variance of the measurement error. Correction functions showed good performance in restoring the jet transverse momentum (pT) spectrum. The methods provide a good framework to study jet quantities and optimize jet reconstruction and correction techniques. We evaluated the performance of the CMS detector for measuring the Emiss T using QCD events. We also studied the contributions from detector resolution, minimum bias pileup, event...

  7. Poro-elasto-plastic behaviour of dry compacted Fo-Ca clay: experiment and modelling. Application to the re-saturation of an engineered clay barrier

    International Nuclear Information System (INIS)

    Lassabatere, Th.; Imbert, Ch.; Etile, M.A.

    1999-01-01

    Many projects of underground repositories for high level radioactive waste involve an engineered clay barrier, placed between the waste canister and the surrounding rock. When hydrated, this barrier seals the gap and provides a good watertightness. The natural clay powder, dried and compacted, exhibits hydro-mechanical couplings during the hydration. Such a coupled behaviour, interesting for the industrial application, has been clearly demonstrated by many studies and laboratory experiments. But the modelling of this behaviour, in order to predict the hydration of the clay barrier, is difficult. A coupled modelling, based, at a macroscopic scale, on the thermodynamics of unsaturated porous media, is proposed. This thermodynamical model founds a general framework for non linear poro-elastic and poro-elasto-plastic coupled behaviours. The symmetries of this coupling, induced by this thermodynamical framework, let us take into account the often neglected influence of the mechanical state on the hydraulic problem of the re-saturation of the clay. The complete resolution of the flow problem, coupled with the mechanical behaviour, leads us to study the influence of the rheological behaviour chosen for the clay (elastic - linear or no linear -, or elastoplastic) on the evaluation of the duration of the re-saturation of the clay barrier). (authors)

  8. An improved billet on billet extrusion process of continuous aluminium alloy shapes for cryogenic applications in the Compact Muon Solenoid experiment

    CERN Document Server

    Tavares, S S

    2003-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments being designed in the framework of the Large Hadron Collider accelerator at CERN. CMS will contain the largest and the most powerful superconducting solenoid magnet ever built in terms of stored energy. It will work at 4.2 K, will have a magnetic length of 12.5 m, with a free bore of 6m and will be manufactured as a layered and modular structure of NbTi cables embedded in a high purity (99.998%) Al- stabiliser. Each layer consists of a wound continuous length of 2.55 km. In order to withstand the high electromagnetic forces, two external aluminium alloy reinforcing sections are foreseen. These reinforcements, of 24 mm multiplied by 18 mm cross-section, will be continuously electron beam (EB) welded to the pure Al-stabiliser. The alloy EN AW-6082 has been selected for the reinforcements due to its excellent extrudability, high strength in the precipitation hardened state, high toughness and strength at cryogenic temperatures and ready EB weldability. Ea...

  9. Airborne In-Situ Measurements of Formaldehyde over California: One Year of Results from the Compact Formaldehyde Fluorescence Experiment (COFFEE) Instrument

    Science.gov (United States)

    Marrero, J. E.; St Clair, J. M.; Yates, E. L.; Ryoo, J. M.; Gore, W.; Swanson, A. K.; Iraci, L. T.; Hanisco, T. F.

    2016-12-01

    Formaldehyde (HCHO) is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere, playing a role in multiple atmospheric processes, such as ozone (O3) production in polluted environments. Due to its short lifetime of only a few hours in daytime, HCHO also serves as tracer of recent photochemical activity. While photochemical oxidation of non-methane hydrocarbons is the dominant source, HCHO can also be emitted directly from fuel combustion, vegetation, and biomass burning. The Compact Formaldehyde FluorescencE Experiment (COFFEE) instrument was built for integration onto the Alpha Jet Atmospheric eXperiment (AJAX) payload, based out of NASA's Ames Research Center (Moffett Field, CA). Using Non-Resonant Laser Induced Fluorescence (NR-LIF), trace concentrations of HCHO can be detected with a sensitivity of 200 parts per trillion. Since its first research flight in December 2015, COFFEE has successfully flown on more than 20 science missions throughout California and Nevada. Presented here are results from these flights, including boundary layer measurements and vertical profiles throughout the tropospheric column. California's San Joaquin Valley is a primary focus, as this region is known for its elevated levels of HCHO as well as O3. Measurements collected in wildfire plumes, urban centers, agricultural lands, and on and off shore comparisons will be presented. In addition, the correlation of HCHO to other trace gases also measured by AJAX, including O3, methane, carbon dioxide, and water vapor will also be shown. Lastly, the implications of these HCHO measurements on calibration and validation of remote sensing data collected by NASA's OMI (Aura) and OMPS (SuomiNPP) satellites will be addressed.

  10. Collisionless Electrostatic Shock Modeling and Simulation

    Science.gov (United States)

    2016-10-21

    equations with piston -like boundary conditions gives a solution for the shock behavior. • Assumes cold upstream ions, therefore neglecting shock...temperature ratio (>10) – Wave Train Wavelength – Shock-Front Mach Number – Reflected Ion Beam Velocity Gathering Experiment Data – Double Plasma Device...experimental shock data. • Inconsistencies in published 1969 double -plasma device data hampered validation. Future Work: Extension to Moderately

  11. Prediction and validation of burnout curves for Goettelborn char using reaction kinetics determined in shock tube experiments

    Energy Technology Data Exchange (ETDEWEB)

    Moors, J.H.J.; Banin, V.E.; Haas, J.H.P.; Weber, R.; Veefkind, A. [Eindhoven University of Technology, Eindhoven (Netherlands). Dept. of Applied Physics

    1999-01-01

    Using a shock tube facility the combustion characteristics of pulverised char ({lt} 10 {mu}m) were measured. A prediction was made for the burnout behaviour of a commercial sized char particle (75-90 {mu}m) in different ambient conditions using a `pseudo kinetic` approach. In this approach the kinetic rate of a surface containing micro pores is determined and these `pseudo kinetics` are then applied to the larger particle not taking into account the micro pores. Comparison of the predictions with measurements done with an isothermal plug flow reactor showed this approach to be valid within experimental error for low burnout. A linear decrease of the kinetic reaction rate with burnout is shown to predict the burnout behaviour in the complete range of burnout. A possible explanation for this linear decrease could be a growing fraction of non-combustible material in the char particles during burnout. 11 refs., 6 figs., 2 tabs.

  12. 28th International Symposium on Shock Waves

    CERN Document Server

    2012-01-01

    The University of Manchester hosted the 28th International Symposium on Shock Waves between 17 and 22 July 2011. The International Symposium on Shock Waves first took place in 1957 in Boston and has since become an internationally acclaimed series of meetings for the wider Shock Wave Community. The ISSW28 focused on the following areas: Blast Waves, Chemically Reacting Flows, Dense Gases and Rarefied Flows, Detonation and Combustion, Diagnostics, Facilities, Flow Visualisation, Hypersonic Flow, Ignition, Impact and Compaction, Multiphase Flow, Nozzle Flow, Numerical Methods, Propulsion, Richtmyer-Meshkov, Shockwave Boundary Layer Interaction, Shock Propagation and Reflection, Shock Vortex Interaction, Shockwave Phenomena and Applications, as well as Medical and Biological Applications. The two Volumes contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 28 and individuals interested in these fields.

  13. New Bayesian inference method using two steps of Markov chain Monte Carlo and its application to shock tube experiment data of Furan oxidation

    KAUST Repository

    Kim, Daesang

    2016-01-06

    A new Bayesian inference method has been developed and applied to Furan shock tube experimental data for efficient statistical inferences of the Arrhenius parameters of two OH radical consumption reactions. The collected experimental data, which consist of time series signals of OH radical concentrations of 14 shock tube experiments, may require several days for MCMC computations even with the support of a fast surrogate of the combustion simulation model, while the new method reduces it to several hours by splitting the process into two steps of MCMC: the first inference of rate constants and the second inference of the Arrhenius parameters. Each step has low dimensional parameter spaces and the second step does not need the executions of the combustion simulation. Furthermore, the new approach has more flexibility in choosing the ranges of the inference parameters, and the higher speed and flexibility enable the more accurate inferences and the analyses of the propagation of errors in the measured temperatures and the alignment of the experimental time to the inference results.

  14. Toxic shock syndrome

    Science.gov (United States)

    Staphylococcal toxic shock syndrome; Toxic shock-like syndrome; TSLS ... Toxic shock syndrome is caused by a toxin produced by some types of staphylococcus bacteria. A similar problem, called toxic shock- ...

  15. Shock wave fabricated ceramic-metal nozzles

    NARCIS (Netherlands)

    Carton, E.P.; Stuivinga, M.E.C.; Keizers, H.L.J.; Verbeek, H.J.; Put, P.J. van der

    1999-01-01

    Shock compaction was used in the fabrication of high temperature ceramic-based materials. The materials' development was geared towards the fabrication of nozzles for rocket engines using solid propellants, for which the following metal-ceramic (cermet) materials were fabricated and tested: B4C-Ti

  16. "Driverless" Shocks in the Interplanetary Medium

    Science.gov (United States)

    Gopalswamy, N.; Kaiser, M. L.; Lara, A.

    1999-01-01

    Many interplanetary shocks have been detected without an obvious driver behind them. These shocks have been thought to be either blast waves from solar flares or shocks due to sudden increase in solar wind speed caused by interactions between large scale open and closed field lines of the Sun. We investigated this problem using a set of interplanetary shock detected {\\it in situ} by the Wind space craft and tracing their solar origins using low frequency radio data obtained by the Wind/WAVES experiment. For each of these "driverless shocks" we could find a unique coronal mass ejections (CME) event observed by the SOHO (Solar and Heliospheric Observatory) coronagraphs. We also found that these CMEs were ejected at large angles from the Sun-Earth line. It appears that the "driverless shocks" are actually driver shocks, but the drivers were not intercepted by the spacecraft. We conclude that the interplanetary shocks are much more extended than the driving CMEs.

  17. Shocking matter to extreme conditions

    International Nuclear Information System (INIS)

    Gupta, Y.M.; Sharma, S.M.

    1997-01-01

    A good understanding of the thermodynamic response of matter at high compression and high energy densities is important to several areas of physics. Shock-wave experiments are uniquely suited for obtaining data at extreme conditions, and a shock-compressed matter can be viewed as a condensed system with or without dissociation or as a strongly coupled plasma. This article reviews work by Da Silva et al. in which irradiances ranging from 5x10 superscript 12 to 2x10 superscript 14 W/cm 2 were used to generate 8- to 10-ns square pulses in liquid deuterium. The authors demonstrated negligible pre-heating of the sample, steady propagation of the shock wave, and direct determination of the shock wave velocity along with particle velocity and density in the shocked state. Da Silva et al. results are compared with models and other experimental information, and the usefulness of the data in other areas is assessed. 11 refs., 1 fig

  18. PDV-based estimation of ejecta particles' mass-velocity function from shock-loaded tin experiment

    Science.gov (United States)

    Franzkowiak, J.-E.; Prudhomme, G.; Mercier, P.; Lauriot, S.; Dubreuil, E.; Berthe, L.

    2018-03-01

    A metallic tin plate with a given surface finish of wavelength λ ≃ 60 μm and amplitude h ≃ 8 μm is explosively driven by an electro-detonator with a shock-induced breakout pressure PSB = 28 GPa (unsupported). The resulting dynamic fragmentation process, the so-called "micro-jetting," is the creation of high-speed jets of matter moving faster than the bulk metallic surface. Hydrodynamic instabilities result in the fragmentation of these jets into micron-sized metallic particles constituting a self-expanding cloud of droplets, whose areal mass, velocity, and particle size distributions are unknown. Lithium-niobate-piezoelectric sensor measured areal mass and Photonic Doppler Velocimetry (PDV) was used to get a time-velocity spectrogram of the cloud. In this article, we present both experimental mass and velocity results and we relate the integrated areal mass of the cloud to the PDV power spectral density with the assumption of a power law particle size distribution. Two models of PDV spectrograms are described. The first one accounts for the speckle statistics of the spectrum and the second one describes an average spectrum for which speckle fluctuations are removed. Finally, the second model is used for a maximum likelihood estimation of the cloud's parameters from PDV data. The estimated integrated areal mass from PDV data is found to agree well with piezoelectric results. We highlight the relevance of analyzing PDV data and correlating different diagnostics to retrieve the physical properties of ejecta particles.

  19. Laser Shock Peening on Zr-based Bulk Metallic Glass and Its Effect on Plasticity: Experiment and Modeling

    Science.gov (United States)

    Cao, Yunfeng; Xie, Xie; Antonaglia, James; Winiarski, Bartlomiej; Wang, Gongyao; Shin, Yung C.; Withers, Philip J.; Dahmen, Karin A.; Liaw, Peter K.

    2015-05-01

    The Zr-based bulk metallic glasses (BMGs) are a new family of attractive materials with good glass-forming ability and excellent mechanical properties, such as high strength and good wear resistance, which make them candidates for structural and biomedical materials. Although the mechanical behavior of BMGs has been widely investigated, their deformation mechanisms are still poorly understood. In particular, their poor ductility significantly impedes their industrial application. In the present work, we show that the ductility of Zr-based BMGs with nearly zero plasticity is improved by a laser shock peening technique. Moreover, we map the distribution of laser-induced residual stresses via the micro-slot cutting method, and then predict them using a three-dimensional finite-element method coupled with a confined plasma model. Reasonable agreement is achieved between the experimental and modeling results. The analyses of serrated flows reveal plentiful and useful information of the underlying deformation process. Our work provides an easy and effective way to extend the ductility of intrinsically-brittle BMGs, opening up wider applications of these materials.

  20. Clinical experience with EDAP LT-01+ extracorporeal shock wave lithotripsy for radiolucent stones; a report of 27 cases

    International Nuclear Information System (INIS)

    Rim, Hee Kwan; Kim, Ho Sung; Rim, Joung Sik

    1994-01-01

    Between February 1990 and February 1993, Radiolucent stones of 27 renal units in 22 patients were treated by extracorporeal shock wave lithotripsy (ESWL) using the EDAP LT-01+. Intravenous urography was done in all patients for the diagnosis of radiolucent stones. Retrograde pyelography, ultrasonography and/or computed tomography was done, if needed. The locations of stones were kidney in 11(40.7 %), upper ureter in 8(29.6 %), lower ureter in 6(22.2 %), bladder in 1(3.7 %), ureteropelvic junction in 1(3.7 %). The average stone size was 10.9mm with a range of 5 to 32mm in maximum diameter. The average numbers of treatment were 2.7 sessions and average storage required was 34.8 in one session. The average treatment time was 40.4 minutes. All the patients showed complete removal of all calculous materials. Of 17 urinary stones analysed by chemical method, 8(47.1 %) were composed of uric acid, 5(29.4 %) of uric acid and calcium, 3 of phosphate and 1 of carbonate and phosphate. Therefore, we conclude that ESWL with EDAP LT-01+ lithotriptor is considered to be an effective noninvasive procedure for treatment of radiolucent stones. (Author)

  1. Diffusion in compacted betonite

    International Nuclear Information System (INIS)

    Muurinen, A.; Rantanen, J.

    1985-01-01

    The objective of this report is to collect the literature bearing on the diffusion in compacted betonite, which has been suggested as possible buffer material for the disposal of spent fuel. Diffusion in a porous, water-saturated material is usually described as diffusion in the pore-water where sorption on the solid matter can delay the migration in the instationary state. There are also models which take into consideration that the sorbed molecules can also move while being sorbed. Diffusion experiments in compacted bentonite have been reported by many authors. Gases, anions, cations and actinides have been used as diffusing molecules. The report collects the results and the information on the measurement methods. On the basis of the results can be concluded that different particles possibly follow different diffusion mechanisms. The parameters which affect the diffusion seem to be for example the size, the electric charge and the sorption properties of the diffusing molecule. The report also suggest the parameters to be used in the diffusion calculation of the safety analyses of spent fuel disposal. (author)

  2. Numerical Study of Richtmyer-Meshkov Instability with Re-Shock

    Science.gov (United States)

    Wong, Man Long; Livescu, Daniel; Lele, Sanjiva

    2017-11-01

    The interaction of a Mach 1.45 shock wave with a perturbed planar interface between two gases with an Atwood number 0.68 is studied through 2D and 3D shock-capturing adaptive mesh refinement (AMR) simulations with physical diffusive and viscous terms. The simulations have initial conditions similar to those in the actual experiment conducted by Poggi et al. [1998]. The development of the flow and evolution of mixing due to the interactions with the first shock and the re-shock are studied together with the sensitivity of various global parameters to the properties of the initial perturbation. Grid resolutions needed for fully resolved and 2D and 3D simulations are also evaluated. Simulations are conducted with an in-house AMR solver HAMeRS built on the SAMRAI library. The code utilizes the high-order localized dissipation weighted compact nonlinear scheme [Wong and Lele, 2017] for shock-capturing and different sensors including the wavelet sensor [Wong and Lele, 2016] to identify regions for grid refinement. First and third authors acknowledge the project sponsor LANL.

  3. Shock Waves

    CERN Document Server

    Jiang, Z

    2005-01-01

    The International Symposium on Shock Waves (ISSW) is a well established series of conferences held every two years in a different location. A unique feature of the ISSW is the emphasis on bridging the gap between physicists and engineers working in fields as different as gas dynamics, fluid mechanics and materials sciences. The main results presented at these meetings constitute valuable proceedings that offer anyone working in this field an authoritative and comprehensive source of reference.

  4. Down with Physics: giant compact muon solenoid (CMS) magnet goes underground at CERN UCR physicists to participate in the international experiment

    CERN Multimedia

    2007-01-01

    "Scientists of the US CMS collaboration, which includes UC riverside physicists, joined colleagues around the world in announcing today that the heaviest piece of the Compact Muon Solenoid particle detector has begun te momentous journey into its experimenta cavern 100 meters underground." (2,5 pages)

  5. Sorption of Sr, Co and Zn on illite: Batch experiments and modelling including Co in-diffusion measurements on compacted samples

    Science.gov (United States)

    Montoya, V.; Baeyens, B.; Glaus, M. A.; Kupcik, T.; Marques Fernandes, M.; Van Laer, L.; Bruggeman, C.; Maes, N.; Schäfer, T.

    2018-02-01

    Experimental investigations on the uptake of divalent cations (Sr, Co and Zn) onto illite (Illite du Puy, Le-Puy-en-Velay, France) were carried out by three different international research groups (Institute for Nuclear Waste Disposal, KIT (Germany), Group Waste & Disposal, SCK-CEN, (Belgium) and Laboratory for Waste Management, PSI (Switzerland)) in the framework of the European FP7 CatClay project. The dependence of solid-liquid distribution ratios (Rd values) on pH at trace metal conditions (sorption edges) and on the metal ion concentration (sorption isotherms) was determined in dilute suspensions of homo-ionic Na-illite (Na-IdP) under controlled N2 atmosphere. The experimental results were modelled using the 2 Site Protolysis Non Electrostatic Surface Complexation and Cation Exchange (2SPNE SC/CE) sorption model. The sorption of Sr depends strongly on ionic strength, while a rather weak pH dependence is observed in a pH range between 3 and 11. The data were modelled with cation exchange reactions, taking into account competition with H, K, Ca, Mg and Al, and surface complexation on weak amphotheric edge sites at higher pH values. The sorption of Co on Na-IdP, however, is strongly pH dependent. Cation exchange on the planar sites and surface complexation on strong and weak amphoteric edge sites were used to describe the Co sorption data. Rd values for Co derived from in-diffusion measurements on compacted Na-IdP samples (bulk-dry density of 1700 kg m-3) between pH 5.0 and 9.0 are in good agreement with the batch sorption data. The equivalence of both approaches to measure sorption was thus confirmed for the present test system. In addition, the results highlight the importance of both major and minor surface species for the diffusive transport behaviour of strongly sorbing metal cations. While surface complexes at the edge sites determine largely the Rd value, the diffusive flux may be governed by those species bound to the planar sites, even at low fractional

  6. Extracorporeal shock wave lithotripsy in the treatment of ureteric stones: Experience from Twam Hospital, United Arab Emirates

    International Nuclear Information System (INIS)

    Ghafoor, M.; Halim, A.

    2002-01-01

    The optimal treatment of ureteric stones, especially the lower ureteric stone, remains controversial. The purpose of this study was to evaluate the role of extracorporeal shock wave lithotripsy (ESWL) in the management of ureteric stones. A total of 99 patients with ureteric stones at different levels were treated with ESWL from 1994 through 1998 at our hospital. All patients were treated using Siemen Lithostar-II Plus Lithotripter. Of 99 patients, 22 were excluded from the study because they had no follow-up records of their stone-free status. The clearance rates for ureteric stones of the other 79 patients treated were stratified according to the site, size and the number of treatment sessions required per stone. The stone size was determined by the widest diameters. Based on stone size, the patients were divided into two groups: A ( 1 0 mm) and B (11-20 mm). The overall all clearance rate for ureteric stones treated with ESWL, irrespective of its site and size, was 78.5%. The overall clearance rate for size A (<-10 mm) stone was 82% and size B (11-20 mm) was 58% regardless of the site of the stone in the ureter. A total of 17 upper ureteric stones were treated with ESWL. The overall clearance rate for upper ureteric stones was 94%. Thirteen patients with mid-ureteric stones were treated with ESWL. The overall clearance rate for the lower ureteric stones was 69.3%. ESWL is safe, effective, noninvasive and a convenient way of treatment for all ureteric stones. The clearance rate for stones in the upper and mid-ureter is above 90%. ESWL being an outpatient procedure without ant need for anesthesia or any pretreatment intervention. It should be considered as the first line of treatment for all stones in the upper and mid-ureter. The clearance for small stones (<1 mm) in the lower third of ureter was 73.8% in our study and for these, ESWL may be considered as a primary therapy. For stones larger than 10 mm in the distal third of ureter, the clearance rate was low

  7. High pressure in situ X-ray diffraction study of MnO to 137 GPa and comparison with shock compression experiment

    Science.gov (United States)

    Yagi, T.; Kondo, T.; Syono, Y.

    1998-07-01

    In order to clarify the nature of the phase transformation in MnO observed at around 90 GPa by shock compression experiment, high pressure in situ X-ray observations were carried out up to 137 GPa. Powdered sample was directly compressed in Mao-Bell type diamond anvil cell and X-ray experiments were carried out using angle dispersive technique by combining synchrotron radiation and imaging plate detector. Distortion of the B1 structured phase was observed above about 40 GPa, which continues to increase up to 90 GPa. Two discontinuous changes of the diffraction profiles were observed at around 90 GPa and 120 GPa. The nature of the intermediate phase between 90 GPa and 120 GPa is not clear yet. It is neither cesium chloride (B2) nor nickel arsenide (B8) structure. On the other hand, the diffraction profile above 120 GPa can be reasonably well explained by the B8 structure. High pressure phases above 90 GPa have metallic luster and all the transformations are reversible on release of pressure.

  8. Cost-effectiveness of extracorporeal shock wave lithotripsy in a poor resource setting: The Okada, Nigeria experience.

    Science.gov (United States)

    Eze, Kenneth C; Irekpita, E; Salami, T A

    2016-01-01

    The first extracorporeal shock wave lithotripsy (ESWL) used in Nigeria was at Igbinedion Hospital and Medical Research Centre (IHMRC), Okada in 1992 and it functioned for 6 consecutive years. The objectives of this study were to analyze the cost-effectiveness of the procedure and highlight the associated factors that led to its failure. A retrospective study of medical records and publications associated with the use of ESWL at IHMRC, Okada, for the period of 1992 to 1998. The study was conducted between January 2003 and November 2008. Unclassified authentic information relating to the use of ESWL and treatment of upper urinary tract stones was obtained from the IHMRC Okada and some government hospitals on hospital bills. Relevant documents in public domains related to the national and international wages and emoluments of medical workers and socioeconomic development of Nigeria within the time the ESWL functioned were studied. A total of 32 patients were treated with 51 treatment sessions which is an average of nine patients per year and an average of two treatment sessions per patient were involved. The reasons for the low patronage were the extremely low stone formation rate of Nigerians, poverty, and out-of-pocket payment system. In addition, each treatment session of ESWL at Okada cost an average of $681.8 compared to $227.3 for open nephrolithotomy in a nearby high profile teaching hospital. The IHMRC, Okada, paid an average annual salary of ₦180,000 ($8,181.8) for each medical consultant compared to ₦120,000 ($5,454.5) paid by federal teaching hospitals in Nigeria within the period. Expatriate consultant doctors from Europe and USA who initially manned the lithotriptor at IHMRC, Okada, were paid much higher salaries. Average annual income of $5,909 for each of the 6 years amounting to a total of $34,771.7 for the six years was realized which could not maintain staff salaries in the hospital leading to staff emigration, decline of the hospital services

  9. Results of molten salt panel and component experiments for solar central receivers: Cold fill, freeze/thaw, thermal cycling and shock, and instrumentation tests

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, J.E.; Ralph, M.E.; Chavez, J.M.; Dunkin, S.R.; Rush, E.E.; Ghanbari, C.M.; Matthews, M.W.

    1995-01-01

    Experiments have been conducted with a molten salt loop at Sandia National Laboratories in Albuquerque, NM to resolve issues associated with the operation of the 10MW{sub e} Solar Two Central Receiver Power Plant located near Barstow, CA. The salt loop contained two receiver panels, components such as flanges and a check valve, vortex shedding and ultrasonic flow meters, and an impedance pressure transducer. Tests were conducted on procedures for filling and thawing a panel, and assessing components and instrumentation in a molten salt environment. Four categories of experiments were conducted: (1) cold filling procedures, (2) freeze/thaw procedures, (3) component tests, and (4) instrumentation tests. Cold-panel and -piping fill experiments are described, in which the panels and piping were preheated to temperatures below the salt freezing point prior to initiating flow, to determine the feasibility of cold filling the receiver and piping. The transient thermal response was measured, and heat transfer coefficients and transient stresses were calculated from the data. Freeze/thaw experiments were conducted with the panels, in which the salt was intentionally allowed to freeze in the receiver tubes, then thawed with heliostat beams. Slow thermal cycling tests were conducted to measure both how well various designs of flanges (e.g., tapered flanges or clamp type flanges) hold a seal under thermal conditions typical of nightly shut down, and the practicality of using these flanges on high maintenance components. In addition, the flanges were thermally shocked to simulate cold starting the system. Instrumentation such as vortex shedding and ultrasonic flow meters were tested alongside each other, and compared with flow measurements from calibration tanks in the flow loop.

  10. Chondrule destruction in nebular shocks

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, Emmanuel; Thompson, Christopher, E-mail: ejacquet@mnhn.fr [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St George Street, Toronto, ON M5S 3H8 (Canada)

    2014-12-10

    Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous protoplanetary disk. However, evidence is mounting that chondrule-forming regions were enriched in solids well above solar abundances. Given the high velocities involved in shock models, destructive collisions would be expected between differently sized grains after passage of the shock front as a result of differential drag. We investigate the probability and outcome of collisions of particles behind a one-dimensional shock using analytic methods as well as a full integration of the coupled mass, momentum, energy, and radiation equations. Destruction of protochondrules seems unavoidable for solid/gas ratios ε ≳ 0.1, and possibly even for solar abundances because of 'sandblasting' by finer dust. A flow with ε ≳ 10 requires much smaller shock velocities (∼2 versus 8 km s{sup –1}) in order to achieve chondrule-melting temperatures, and radiation trapping allows slow cooling of the shocked fragments. Initial destruction would still be extensive; although re-assembly of millimeter-sized particles would naturally occur by grain sticking afterward, the compositional heterogeneity of chondrules may be difficult to reproduce. We finally note that solids passing through small-scale bow shocks around few kilometer-sized planetesimals might experience partial melting and yet escape fragmentation.

  11. INTERFERENCE OF COUNTERPROPAGATING SHOCK WAVES

    Directory of Open Access Journals (Sweden)

    P. V. Bulat

    2015-03-01

    Full Text Available The subject of study. We examined the interaction of counterpropagating shock waves. The necessity of counterpropagating shock waves studying occurs at designing of high Mach number modern internal compression air intakes, Ramjets with subsonic and supersonic combustion, in asymmetrical supersonic nozzles and in some other cases. In a sense, this problem is a generalization of the case of an oblique shock reflection from the wall or from the plane of symmetry. With the renewed vigor, the interest to this problem emerged at the end of the 90s. This was due to the start of the programs for flight study at hypersonic speeds. The first experiments performed with air intakes, which realized the interaction of counterpropagating shock waves have shown that the change in flow velocity is accompanied by abrupt alteration of shock-wave structure, the occurrence of nonstationary and oscillatory phenomena. With an increase of flow velocity these phenomena undesirable for aircraft structure became more marked. The reason is that there are two fundamentally different modes of interaction of counterpropagating shock waves: a four-wave regular and a five-wave irregular. The transition from one mode to another can be nonstationary abrupt or gradual, it can also be accompanied by hysteresis. Main results. Criteria for the transition from regular reflection of counterpropagating shock waves to irregular are described: the criterion of von Neumann and the stationary Mach configuration criterion. We described areas in which the transition from one reflection type to another is possible only in abrupt way, as well as areas of possible gradual transition. Intensity dependences of the reflected shock waves from the intensity of interacting counterpropagating shocks were given. Qualitative pictures of shock-wave structures arising from the interaction of counterpropagating shock waves were shown. Calculation results of the intensity of outgoing gas

  12. Self-Compacting Concrete

    OpenAIRE

    Okamura, Hajime; Ouchi, Masahiro

    2003-01-01

    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  13. Compact Polarimetry Potentials

    Science.gov (United States)

    Truong-Loi, My-Linh; Dubois-Fernandez, Pascale; Pottier, Eric

    2011-01-01

    The goal of this study is to show the potential of a compact-pol SAR system for vegetation applications. Compact-pol concept has been suggested to minimize the system design while maximize the information and is declined as the ?/4, ?/2 and hybrid modes. In this paper, the applications such as biomass and vegetation height estimates are first presented, then, the equivalence between compact-pol data simulated from full-pol data and compact-pol data processed from raw data as such is shown. Finally, a calibration procedure using external targets is proposed.

  14. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    "Revised to reflect modern pharmaceutical compacting techniques, this Second Edition guides pharmaceutical engineers, formulation scientists, and product development and quality assurance personnel...

  15. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  16. Effects of response-shock interval and shock intensity on free-operant avoidance responding in the pigeon1

    Science.gov (United States)

    Klein, Marty; Rilling, Mark

    1972-01-01

    Two experiments investigated free-operant avoidance responding with pigeons using a treadle-pressing response. In Experiment I, pigeons were initially trained on a free-operant avoidance schedule with a response-shock interval of 32 sec and a shock-shock interval of 10 sec, and were subsequently exposed to 10 values of the response-shock parameter ranging from 2.5 to 150 sec. The functions relating response rate to response-shock interval were similar to the ones reported by Sidman in his 1953 studies employing rats, and were independent of the order of presentation of the response-shock values. Shock rates decreased as response-shock duration increased. In Experiment II, a free-operant avoidance schedule with a response-shock interval of 20 sec and a shock-shock interval of 5 sec was used, and shock intensities were varied over five values ranging from 2 to 32 mA. Response rates increased markedly as shock intensity increased from 2 to 8 mA, but rates changed little with further increases in shock intensity. Shock rates decreased as intensity increased from 2 to 8 mA, and showed little change as intensity increased from 8 to 32 mA. PMID:4652617

  17. Engineering aspects of compact stellarators

    International Nuclear Information System (INIS)

    Nelson, B.E.; Benson, R.D.; Brooks, A.

    2003-01-01

    Compact stellarators could combine the good confinement and high beta of a tokamak with the inherently steady state, disruption-free characteristics of a stellarator. Two U.S. compact stellarator facilities are now in the conceptual design phase: the National Compact Stellarator Experiment (NCSX) and the Quasi- Poloidal Stellarator (QPS). NCSX has a major radius of 1.4 m and a toroidal field up to 2 T. The primary feature of both NCSX and QPS is the set of modular coils that provide the basic magnetic configuration. These coils represent a major engineering challenge due to the complex shape, precise geometric accuracy, and high current density of the windings. The winding geometry is too complex for conventional hollow copper conductor construction. Instead, the modular coils will be wound with flexible, multi strand cable conductor that has been compacted to a 75% copper packing fraction. Inside the NCSX coil set and surrounding the plasma is a highly contoured vacuum vessel. The vessel consists of three identical, 120 deg. segments that are bolted together at double sealed joints. The QPS device has a major radius of 0.9 m, a toroidal field of 1 T, and an aspect ratio of only 2.7. Instead of an internal vacuum vessel, the QPS modular coils will operate in an external vacuum tank. (author)

  18. Collisions on relativistic nuclei: shock waves

    International Nuclear Information System (INIS)

    Gudima, K.K.; Toneev, V.D.

    1976-01-01

    Experiments are analysed which indicate the possible generation of shock waves in collisions of two nuclei. Another interpretation of these data is proposed and the concerned new experiments are discussed

  19. 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.)

  20. Compaction properties of isomalt

    NARCIS (Netherlands)

    Bolhuis, Gerad K.; Engelhart, Jeffrey J. P.; Eissens, Anko C.

    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of

  1. Model Compaction Equation

    African Journals Online (AJOL)

    The currently proposed model compaction equation was derived from data sourced from the. Niger Delta and it relates porosity to depth for sandstones under hydrostatic pressure condition. The equation is useful in predicting porosity and compaction trend in hydrostatic sands of the. Niger Delta. GEOLOGICAL SETTING OF ...

  2. Diaphragmless shock wave generators for industrial applications of shock waves

    Science.gov (United States)

    Hariharan, M. S.; Janardhanraj, S.; Saravanan, S.; Jagadeesh, G.

    2011-06-01

    The prime focus of this study is to design a 50 mm internal diameter diaphragmless shock tube that can be used in an industrial facility for repeated loading of shock waves. The instantaneous rise in pressure and temperature of a medium can be used in a variety of industrial applications. We designed, fabricated and tested three different shock wave generators of which one system employs a highly elastic rubber membrane and the other systems use a fast acting pneumatic valve instead of conventional metal diaphragms. The valve opening speed is obtained with the help of a high speed camera. For shock generation systems with a pneumatic cylinder, it ranges from 0.325 to 1.15 m/s while it is around 8.3 m/s for the rubber membrane. Experiments are conducted using the three diaphragmless systems and the results obtained are analyzed carefully to obtain a relation between the opening speed of the valve and the amount of gas that is actually utilized in the generation of the shock wave for each system. The rubber membrane is not suitable for industrial applications because it needs to be replaced regularly and cannot withstand high driver pressures. The maximum shock Mach number obtained using the new diaphragmless system that uses the pneumatic valve is 2.125 ± 0.2%. This system shows much promise for automation in an industrial environment.

  3. New Bayesian inference method using two steps of Markov chain Monte Carlo and its application to shock tube experiment data of Furan oxidation

    KAUST Repository

    Kim, Daesang; El Gharamti, Iman; Bisetti, Fabrizio; Farooq, Aamir; Knio, Omar

    2016-01-01

    A new Bayesian inference method has been developed and applied to Furan shock tube experimental data for efficient statistical inferences of the Arrhenius parameters of two OH radical consumption reactions. The collected experimental data, which

  4. Porewater chemistry in compacted bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Muurinen, A.; Lehikoinen, J. [VTT Chemical Technology, Espoo (Finland)

    1999-03-01

    In this study, the porewater chemistry in compacted bentonite, considered as an engineered barrier in the repository of spent fuel, has been studied in interaction experiments. Many parameters, like the composition and density of bentonite, composition of the solution, bentonite-to-water ratio (B/W), surrounding conditions and experimental time have been varied in the experiments. At the end of the interaction the equilibrating solution, the porewaters squeezed out of the bentonite samples, and bentonites themselves were analyzed to give information for the interpretation and modelling of the interaction. Equilibrium modelling was performed with the HYDRAQL/CE computer code 33 refs.

  5. Shock-induced devolatilization of calcite

    Science.gov (United States)

    Boslough, M. B.; Ahrens, T. J.; Vizgirda, J.; Becker, R. H.; Epstein, S.

    1982-01-01

    Experimental measurements of the release adiabats by Vizgirda (1981) indicate that substantial vaporization takes place upon release from shock pressures of 37 GPa for calcite and 14 GPa for aragonite. The present investigation includes the first controlled partial vaporization experiments on calcite. The experiments were conducted to test the predictions of the release adiabat experiments. The quantities of the gaseous species produced from shocked calcite and their carbon and oxygen isotopic compositions were determined, and the shock-induced effect on the Mn(2+) electron spin resonance spectrum in the shock-recovered calcite was observed. On the basis of the obtained results, it is concluded that shock stresses at the 17-18 GPa level give rise to volatilization of 0.03-0.3 (mole) percent of calcite to CO2 and CO. The devolatilization of calcite occurs at low pressure at significantly lower entropy densities than predicted on the basis of thermodynamic continuum models.

  6. Mouse Embryo Compaction.

    Science.gov (United States)

    White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

    2016-01-01

    Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. © 2016 Elsevier Inc. All rights reserved.

  7. Compact stellarator coils

    International Nuclear Information System (INIS)

    Pomphrey, N.; Berry, L.A.; Boozer, A.H.

    2001-01-01

    Experimental devices to study the physics of high-beta (β>∼4%), low aspect ratio (A<∼4.5) stellarator plasmas require coils that will produce plasmas satisfying a set of physics goals, provide experimental flexibility, and be practical to construct. In the course of designing a flexible coil set for the National Compact Stellarator Experiment, we have made several innovations that may be useful in future stellarator design efforts. These include: the use of Singular Value Decomposition methods for obtaining families of smooth current potentials on distant coil winding surfaces from which low current density solutions may be identified; the use of a Control Matrix Method for identifying which few of the many detailed elements of the stellarator boundary must be targeted if a coil set is to provide fields to control the essential physics of the plasma; the use of Genetic Algorithms for choosing an optimal set of discrete coils from a continuum of potential contours; the evaluation of alternate coil topologies for balancing the tradeoff between physics objective and engineering constraints; the development of a new coil optimization code for designing modular coils, and the identification of a 'natural' basis for describing current sheet distributions. (author)

  8. Collisionless electrostatic shocks

    DEFF Research Database (Denmark)

    Andersen, H.K.; Andersen, S.A.; Jensen, Vagn Orla

    1970-01-01

    An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth......An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth...

  9. Entropy Generation Across Earth's Bow Shock

    Science.gov (United States)

    Parks, George K.; McCarthy, Michael; Fu, Suiyan; Lee E. s; Cao, Jinbin; Goldstein, Melvyn L.; Canu, Patrick; Dandouras, Iannis S.; Reme, Henri; Fazakerley, Andrew; hide

    2011-01-01

    Earth's bow shock is a transition layer that causes an irreversible change in the state of plasma that is stationary in time. Theories predict entropy increases across the bow shock but entropy has never been directly measured. Cluster and Double Star plasma experiments measure 3D plasma distributions upstream and downstream of the bow shock that allow calculation of Boltzmann's entropy function H and his famous H-theorem, dH/dt O. We present the first direct measurements of entropy density changes across Earth's bow shock. We will show that this entropy generation may be part of the processes that produce the non-thermal plasma distributions is consistent with a kinetic entropy flux model derived from the collisionless Boltzmann equation, giving strong support that solar wind's total entropy across the bow shock remains unchanged. As far as we know, our results are not explained by any existing shock models and should be of interests to theorists.

  10. Small Valdivia compact spaces

    CERN Document Server

    Kubi's, W; Kubi\\'s, Wieslaw; Michalewski, Henryk

    2005-01-01

    We prove a preservation theorem for the class of Valdivia compact spaces, which involves inverse sequences of ``simple'' retractions. Consequently, a compact space of weight $\\loe\\aleph_1$ is Valdivia compact iff it is the limit of an inverse sequence of metric compacta whose bonding maps are retractions. As a corollary, we show that the class of Valdivia compacta of weight at most $\\aleph_1$ is preserved both under retractions and under open 0-dimensional images. Finally, we characterize the class of all Valdivia compacta in the language of category theory, which implies that this class is preserved under all continuous weight preserving functors.

  11. Does soil compaction increase floods? A review

    Science.gov (United States)

    Alaoui, Abdallah; Rogger, Magdalena; Peth, Stephan; Blöschl, Günter

    2018-02-01

    Europe has experienced a series of major floods in the past years which suggests that flood magnitudes may have increased. Land degradation due to soil compaction from crop farming or grazing intensification is one of the potential drivers of this increase. A literature review suggests that most of the experimental evidence was generated at plot and hillslope scales. At larger scales, most studies are based on models. There are three ways in which soil compaction affects floods at the catchment scale: (i) through an increase in the area affected by soil compaction; (ii) by exacerbating the effects of changes in rainfall, especially for highly degraded soils; and (iii) when soil compaction coincides with soils characterized by a fine texture and a low infiltration capacity. We suggest that future research should focus on better synthesising past research on soil compaction and runoff, tailored field experiments to obtain a mechanistic understanding of the coupled mechanical and hydraulic processes, new mapping methods of soil compaction that combine mechanical and remote sensing approaches, and an effort to bridge all disciplines relevant to soil compaction effects on floods.

  12. Overview of the Performance of the Compact Total Electron Content Sensor (CTECS) on the Space Environmental NanoSatellite Experiment (SENSE)

    Science.gov (United States)

    Bishop, R. L.; Hansel, S.; Stoffel, D.; Ping, D.; Bardeen, J.; Chin, A.; Bielat, S.; Mulligan, T. L.

    2014-12-01

    The Air Force's Space & Missile Systems Center (SMC) SENSE mission consists of two identical cubesat buses with space weather payloads. One of the goals of the SENSE mission is to demonstrate the operational potential and usefulness of space weather measurements from a cubesat platform. The payloads on the two cubesats include the Cubesat Tiny Ionospheric Photometer (SRI), Wind Ion Neutral Composite Suite (NRL), and Compact Total Electron Content GPS radio occultation sensor (CTECS). After initial contact with both space vehicles (SV), we were able to confirm successful operation of both CTECS. Because of power issues on SV2, only SV1 has provided consistent data. In this presentation, we present an overview of the CTECS sensor. Then we present initial CTECS data, discuss the data quality, and lessons learned.

  13. Geometrical shock dynamics for magnetohydrodynamic fast shocks

    KAUST Repository

    Mostert, W.; Pullin, D. I.; Samtaney, Ravi; Wheatley, V.

    2016-01-01

    We describe a formulation of two-dimensional geometrical shock dynamics (GSD) suitable for ideal magnetohydrodynamic (MHD) fast shocks under magnetic fields of general strength and orientation. The resulting area–Mach-number–shock-angle relation is then incorporated into a numerical method using pseudospectral differentiation. The MHD-GSD model is verified by comparison with results from nonlinear finite-volume solution of the complete ideal MHD equations applied to a shock implosion flow in the presence of an oblique and spatially varying magnetic field ahead of the shock. Results from application of the MHD-GSD equations to the stability of fast MHD shocks in two dimensions are presented. It is shown that the time to formation of triple points for both perturbed MHD and gas-dynamic shocks increases as (Formula presented.), where (Formula presented.) is a measure of the initial Mach-number perturbation. Symmetry breaking in the MHD case is demonstrated. In cylindrical converging geometry, in the presence of an azimuthal field produced by a line current, the MHD shock behaves in the mean as in Pullin et al. (Phys. Fluids, vol. 26, 2014, 097103), but suffers a greater relative pressure fluctuation along the shock than the gas-dynamic shock. © 2016 Cambridge University Press

  14. Geometrical shock dynamics for magnetohydrodynamic fast shocks

    KAUST Repository

    Mostert, W.

    2016-12-12

    We describe a formulation of two-dimensional geometrical shock dynamics (GSD) suitable for ideal magnetohydrodynamic (MHD) fast shocks under magnetic fields of general strength and orientation. The resulting area–Mach-number–shock-angle relation is then incorporated into a numerical method using pseudospectral differentiation. The MHD-GSD model is verified by comparison with results from nonlinear finite-volume solution of the complete ideal MHD equations applied to a shock implosion flow in the presence of an oblique and spatially varying magnetic field ahead of the shock. Results from application of the MHD-GSD equations to the stability of fast MHD shocks in two dimensions are presented. It is shown that the time to formation of triple points for both perturbed MHD and gas-dynamic shocks increases as (Formula presented.), where (Formula presented.) is a measure of the initial Mach-number perturbation. Symmetry breaking in the MHD case is demonstrated. In cylindrical converging geometry, in the presence of an azimuthal field produced by a line current, the MHD shock behaves in the mean as in Pullin et al. (Phys. Fluids, vol. 26, 2014, 097103), but suffers a greater relative pressure fluctuation along the shock than the gas-dynamic shock. © 2016 Cambridge University Press

  15. Compact turbidity meter

    Science.gov (United States)

    Hirschberg, J. G.

    1979-01-01

    Proposed monitor that detects back-reflected infrared radiation makes in situ turbidity measurements of lakes, streams, and other bodies of water. Monitor is compact, works well in daylight as at night, and is easily operated in rough seas.

  16. Temperature evolution during compaction of pharmaceutical powders.

    Science.gov (United States)

    Zavaliangos, Antonios; Galen, Steve; Cunningham, John; Winstead, Denita

    2008-08-01

    A numerical approach to the prediction of temperature evolution in tablet compaction is presented here. It is based on a coupled thermomechanical finite element analysis and a calibrated Drucker-Prager Cap model. This approach is capable of predicting transient temperatures during compaction, which cannot be assessed by experimental techniques due to inherent test limitations. Model predictions are validated with infrared (IR) temperature measurements of the top tablet surface after ejection and match well with experiments. The dependence of temperature fields on speed and degree of compaction are naturally captured. The estimated transient temperatures are maximum at the end of compaction at the center of the tablet and close to the die wall next to the powder/die interface.

  17. Compaction of FGD-gypsum

    NARCIS (Netherlands)

    Stoop, B.T.J.; Larbi, J.A.; Heijnen, W.M.M.

    1996-01-01

    It is shown that it is possible to produce compacted gypsum with a low porosity and a high strength on a laboratory scale by uniaxial compaction of flue gas desulphurization (FGD-) gypsum powder. Compacted FGD-gypsum cylinders were produced at a compaction pres-sure between 50 and 500 MPa yielding

  18. On cylindrically converging shock waves shaped by obstacles

    Energy Technology Data Exchange (ETDEWEB)

    Eliasson, V; Henshaw, W D; Appelo, D

    2007-07-16

    Motivated by recent experiments, numerical simulations were performed of cylindrically converging shock waves. The converging shocks impinged upon a set of zero to sixteen regularly space obstacles. For more than two obstacles the resulting diffracted shock fronts formed polygonal shaped patterns near the point of focus. The maximum pressure and temperature as a function of number of obstacles were studied. The self-similar behavior of cylindrical, triangular and square-shaped shocks were also investigated.

  19. Dissolution and time-dependent compaction of albite sand: experiments at 100°C and 160°C in pH-buffered organic acids and distilled water

    Science.gov (United States)

    Hajash, Andrew; Carpenter, Thomas D.; Dewers, Thomas A.

    1998-09-01

    Aqueous fluids are important in the diagenesis and deformation of crustal rocks. Both chemical and physical interactions are involved and often they are strongly coupled. For example, pore waters not only dissolve, transport, and precipitate chemical species, but they also substantially affect the mechanical behavior of the rocks that contain them. Stresses magnified at grain contacts by differences in pore-fluid pressure ( Pp) and confining pressure ( Pc) can, in turn, influence the rate and extent of chemical exchange. To begin investigation of these coupled systems, compaction experiments were conducted using albite sand (250-500 μm) and distilled water (pH 5.8), 0.07 M acetate (pH 4.7), and 0.07 M acetate + 0.005 M citrate (pH 4.4) solutions in a hydrothermal flow-through system at conditions that simulate diagenesis. Pore-fluid chemistry and pore-volume loss were monitored to quantify the effects of organic acids on time-dependent compaction rates. The effects of stress and fluid chemistry on the dissolution kinetics were also examined. Albite dissolution rates, monitored by steady-state fluid chemistry, increased when an effective pressure ( Pe= Pc- Pp) was applied, probably due to increases in total surface area caused by grain breakage at contacts. These effects were transient in distilled water, however, Si and Al concentrations remained elevated in the acetate pore fluid. The average Si-based release rates indicate ≈35% increase in reactive surface area by application of Pe=34.5 MPa. At 100°C with Pe=34.5 MPa, steady-state Si concentrations were ≈2.3 times higher in 0.07 M acetate and 5.8 times higher in 0.07 M acetate + 0.005 M citrate than in distilled water. Al increased by even larger factors (3× in the acetate buffer and 10× in the citrate solution). These changes in fluid chemistry are attributed to both pH and ligand-enhanced reactions. Albite dissolution appears to be controlled by surface complexation reactions at Al sites. Rapid

  20. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  1. Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

    Science.gov (United States)

    Kristiawan, S. A.; Sunarmasto; Tyas, G. P.

    2016-02-01

    Concrete is susceptible to a variety of chemical attacks. In the sulfuric acid environment, concrete is subjected to a combination of sulfuric and acid attack. This research is aimed to investigate the degradation of self-compacting concrete (SCC) due to sulfuric acid attack based on measurement of compressive strength loss and diameter change. Since the proportion of SCC contains higher cement than that of normal concrete, the vulnerability of this concrete to sulfuric acid attack could be reduced by partial replacement of cement with fly ash at high volume level. The effect of high volume fly ash at 50-70% cement replacement levels on the extent of degradation owing to sulfuric acid will be assessed in this study. It can be shown that an increase in the utilization of fly ash to partially replace cement tends to reduce the degradation as confirmed by less compressive strength loss and diameter change. The effect of fly ash to reduce the degradation of SCC is more pronounced at a later age.

  2. Active particle control experiments and critical particle flux discriminating between the wall pumping and fuelling in the compact plasma wall interaction device CPD spherical tokamak

    International Nuclear Information System (INIS)

    Zushi, H.; Sakamoto, M.; Yoshinaga, T.; Higashizono, Y.; Hanada, K.; Yoshida, N.; Tokunaga, K.; Kawasaki, S.; Sato, K. N.; Nakamura, K.; Idei, H.; Hirooka, Y.; Bhattacharyay, R.; Okamoto, K.; Miyazaki, T.; Honma, H.; Nakashima, Y.; Nishino, N.; Kado, S.; Shikama, T.

    2009-01-01

    Two approaches associated with wall recycling have been performed in a small spherical tokamak device CPD (compact plasma wall interaction experimental device), that is, (1) demonstration of active particle recycling control, namely, 'active wall pumping' using a rotating poloidal limiter whose surface is continuously gettered by lithium and (2) a basic study of the key parameters which discriminates between 'wall pumping and fuelling'. For the former, active control of 'wall pumping' has been demonstrated during 50 kW RF current drive discharges whose pulse length is typically ∼300 ms. Although the rotating limiter is located at the outer board, as soon as the rotating drum is gettered with lithium, hydrogen recycling measured with H α spectroscopy decreases by about a factor of 3 not only near the limiter but also in the centre stack region. Also, the oxygen impurity level measured with O II spectroscopy is reduced by about a factor of 3. As a consequence of the reduced recycling and impurity level, RF driven current has nearly doubled at the same vertical magnetic field. For the latter, global plasma wall interaction with plasma facing components in the vessel is studied in a simple torus produced by electron cyclotron waves with I p -4 to ∼0.1 x 10 -4 Torr during the experimental campaign (∼3000 shots). In the wall pumping pressure range the wall pumping fraction is reduced with increasing surface temperature up to 150 deg. C.

  3. PIV tracer behavior on propagating shock fronts

    International Nuclear Information System (INIS)

    Glazyrin, Fyodor N; Mursenkova, Irina V; Znamenskaya, Irina A

    2016-01-01

    The present work was aimed at the quantitative particle image velocimetry (PIV) measurement of a velocity field near the front of a propagating shock wave and the study of the dynamics of liquid tracers crossing the shock front. For this goal, a shock tube with a rectangular cross-section (48  ×  24 mm) was used. The flat shock wave with Mach numbers M  =  1.4–2.0 propagating inside the tube channel was studied as well as an expanding shock wave propagating outside the channel with M  =  1.2–1.8 at its main axis. The PIV imaging of the shock fronts was carried out with an aerosol of dioctyl sebacate (DEHS) as tracer particles. The pressures of the gas in front of the shock waves studied ranged from 0.013 Mpa to 0.1 MPa in the series of experiments. The processed PIV data, compared to the 1D normal shock theory, yielded consistent values of wake velocity immediately behind the plain shock wave. Special attention was paid to the blurring of the velocity jump on the shock front due to the inertial particle lag and peculiarities of the PIV technique. A numerical algorithm was developed for analysis and correction of the PIV data on the shock fronts, based on equations of particle-flow interaction. By application of this algorithm, the effective particle diameter of the DEHS aerosol tracers was estimated as 1.03  ±  0.12 μm. A number of different formulations for particle drag were tested with this algorithm, with varying success. The results show consistency with previously reported experimental data obtained for cases of stationary shock waves. (paper)

  4. Shock compression of simulated adobe

    Science.gov (United States)

    Braithwaite, C. H.; Church, P. D.; Gould, P. J.; Stewart, B.; Jardine, A. P.

    2017-01-01

    A series of plate impact experiments were conducted to investigate the shock response of a simulant for adobe, a traditional form of building material widely used around the world. Air dried bricks were sourced from the London brick company, dry machined and impacted at a range of velocities in a single stage gas gun. The shock Hugoniot was determined (Us =2.26up+0.37) as well as release information. The material was found to behave in a manner which was similar to that of loose sand and considerably less stiff than a weak porous sandstone. The effect of any cementing of the grains was examined by shocking powdered samples contained within a cell arrangement.

  5. The ''injection problem'' for quasiparallel shocks

    International Nuclear Information System (INIS)

    Zank, G. P.; Rice, W. K. M.; le Roux, J. A.; Cairns, I. H.; Webb, G. M.

    2001-01-01

    For a particle to be accelerated diffusively at a shock by the first-order Fermi acceleration mechanism, the particle must be sufficiently energetic that it can scatter across all the micro- and macrostructure of the shock, experiencing compression between the converging upstream and downstream states. This is the well-known ''injection problem.'' Here the interaction of ions with the ramp of a quasiparallel shock is investigated. Some ions incident on the shock experience specular reflection, caused either by the cross-shock electrostatic potential or by mirroring as the magnetic field is bent and compressed through the ramp. Scattering of reflected ions by self-generated and pre-existing turbulence in the region upstream of the shock then acts to trap backstreaming ions and return them to the ramp, where some experience further reflections. Such repeated reflections and scattering energize a subpopulation of ions up to energies sufficiently large that they can be diffusively shock accelerated. Two ion distributions are considered: pickup ions which are assumed to be described by a shell distribution, are thermal solar wind ions which may be described by a kappa distribution. Injection efficiencies are found analytically to be very high for pickup ions and much lower for thermal solar wind ions, suggesting that this injection mechanism, stochastic reflected ion or SRI acceleration, is a natural precursor for the acceleration of the anomalous cosmic ray component at a quasiparallel shock. While significantly less efficient, SRI acceleration is also viable for thermal solar wind ions described by a kappa distribution

  6. Physically detached 'compact groups'

    Science.gov (United States)

    Hernquist, Lars; Katz, Neal; Weinberg, David H.

    1995-01-01

    A small fraction of galaxies appear to reside in dense compact groups, whose inferred crossing times are much shorter than a Hubble time. These short crossing times have led to considerable disagreement among researchers attempting to deduce the dynamical state of these systems. In this paper, we suggest that many of the observed groups are not physically bound but are chance projections of galaxies well separated along the line of sight. Unlike earlier similar proposals, ours does not require that the galaxies in the compact group be members of a more diffuse, but physically bound entity. The probability of physically separated galaxies projecting into an apparent compact group is nonnegligible if most galaxies are distributed in thin filaments. We illustrate this general point with a specific example: a simulation of a cold dark matter universe, in which hydrodynamic effects are included to identify galaxies. The simulated galaxy distribution is filamentary and end-on views of these filaments produce apparent galaxy associations that have sizes and velocity dispersions similar to those of observed compact groups. The frequency of such projections is sufficient, in principle, to explain the observed space density of groups in the Hickson catalog. We discuss the implications of our proposal for the formation and evolution of groups and elliptical galaxies. The proposal can be tested by using redshift-independent distance estimators to measure the line-of-sight spatial extent of nearby compact groups.

  7. Revisiting the thermal effect on shock wave propagation in weakly ionized plasmas

    International Nuclear Information System (INIS)

    Zhou, Qianhong; Dong, Zhiwei; Yang, Wei

    2016-01-01

    Many researchers have investigated shock propagation in weakly ionized plasmas and observed the following anomalous effects: shock acceleration, shock recovery, shock weakening, shock spreading, and splitting. It was generally accepted that the thermal effect can explain most of the experimental results. However, little attention was paid to the shock recovery. In this paper, the shock wave propagation in weakly ionized plasmas is studied by fluid simulation. It is found that the shock acceleration, weakening, and splitting appear after it enters the plasma (thermal) region. The shock splits into two parts right after it leaves the thermal region. The distance between the splitted shocks keeps decreasing until they recover to one. This paper can explain a whole set of features of the shock wave propagation in weakly ionized plasmas. It is also found that both the shock curvature and the splitting present the same photoacoustic deflection (PAD) signals, so they cannot be distinguished by the PAD experiments.

  8. Surface instabilities in shock loaded granular media

    Science.gov (United States)

    Kandan, K.; Khaderi, S. N.; Wadley, H. N. G.; Deshpande, V. S.

    2017-12-01

    The initiation and growth of instabilities in granular materials loaded by air shock waves are investigated via shock-tube experiments and numerical calculations. Three types of granular media, dry sand, water-saturated sand and a granular solid comprising PTFE spheres were experimentally investigated by air shock loading slugs of these materials in a transparent shock tube. Under all shock pressures considered here, the free-standing dry sand slugs remained stable while the shock loaded surface of the water-saturated sand slug became unstable resulting in mixing of the shocked air and the granular material. By contrast, the PTFE slugs were stable at low pressures but displayed instabilities similar to the water-saturated sand slugs at higher shock pressures. The distal surfaces of the slugs remained stable under all conditions considered here. Eulerian fluid/solid interaction calculations, with the granular material modelled as a Drucker-Prager solid, reproduced the onset of the instabilities as seen in the experiments to a high level of accuracy. These calculations showed that the shock pressures to initiate instabilities increased with increasing material friction and decreasing yield strain. Moreover, the high Atwood number for this problem implied that fluid/solid interaction effects were small, and the initiation of the instability is adequately captured by directly applying a pressure on the slug surface. Lagrangian calculations with the directly applied pressures demonstrated that the instability was caused by spatial pressure gradients created by initial surface perturbations. Surface instabilities are also shown to exist in shock loaded rear-supported granular slugs: these experiments and calculations are used to infer the velocity that free-standing slugs need to acquire to initiate instabilities on their front surfaces. The results presented here, while in an idealised one-dimensional setting, provide physical understanding of the conditions required to

  9. Miniature shock tube for laser driven shocks.

    Science.gov (United States)

    Busquet, Michel; Barroso, Patrice; Melse, Thierry; Bauduin, Daniel

    2010-02-01

    We describe in this paper the design of a miniature shock tube (smaller than 1 cm(3)) that can be placed in a vacuum vessel and allows transverse optical probing and longitudinal backside extreme ultraviolet emission spectroscopy in the 100-500 A range. Typical application is the study of laser launched radiative shocks, in the framework of what is called "laboratory astrophysics."

  10. Are Credit Shocks Supply or Demand Shocks?

    OpenAIRE

    Bijapur, Mohan

    2013-01-01

    This paper provides new insights into the relationship between the supply of credit and the macroeconomy. We present evidence that credit shocks constitute shocks to aggregate supply in that they have a permanent effect on output and cause inflation to rise in the short term. Our results also suggest that the effects on aggregate supply have grown stronger in recent decades.

  11. Shock absorbing structure

    International Nuclear Information System (INIS)

    Kojima, Naoki; Matsushita, Kazuo.

    1992-01-01

    Small pieces of shock absorbers are filled in a space of a shock absorbing vessel which is divided into a plurality of sections by partitioning members. These sections function to prevent excess deformation or replacement of the fillers upon occurrence of falling accident. Since the shock absorbing small pieces in the shock absorbing vessel are filled irregularly, shock absorbing characteristics such as compression strength is not varied depending on the direction, but they exhibit excellent shock absorbing performance. They surely absorb shocks exerted on a transportation vessel upon falling or the like. If existing artificial fillers such as pole rings made of metal or ceramic and cut pieces such as alumium extrusion molding products are used as the shock absorbing pieces, they have excellent fire-proofness and cold resistance since the small pieces are inflammable and do not contain water. (T.M.)

  12. Melting under shock compression

    International Nuclear Information System (INIS)

    Bennett, B.I.

    1980-10-01

    A simple model, using experimentally measured shock and particle velocities, is applied to the Lindemann melting formula to predict the density, temperature, and pressure at which a material will melt when shocked from room temperature and zero pressure initial conditions

  13. Maintaining an effective and efficient control system for the Electromagnetic Calorimeter of the Compact Muon Solenoid experiment during Long-Term Operations of CERN�??s Large Hadron Collider

    CERN Document Server

    Holme, Oliver

    2012-01-01

    The sub-detectors of the Compact Muon Solenoid (CMS) multi-purpose particle detector at the CERN Large Hadron Collider (LHC) have been collecting physics data from particle collisions for almost three years. During this period, the CMS Electromagnetic Calorimeter (ECAL) Detector Control System (DCS) has contributed to the high level of availability of the experiment. This paper presents the current architecture of this distributed and heterogeneous control system alongside plans and developments for future improvements. To ensure that the system can efficiently operate and adapt to changes throughout the required operation lifetime of more than a decade, the potential legacy aspects of this kind of control system must be carefully managed. Such issues include evolving system requirements, turnover of staff members, potential benefits from new technologies and the need to follow release schedules of external software dependencies. The techniques and results of the work to continually maintain, improve and stre...

  14. Effects of Atwood number on shock focusing in shock-cylinder interaction

    Science.gov (United States)

    Ou, Junfeng; Ding, Juchun; Luo, Xisheng; Zhai, Zhigang

    2018-02-01

    The evolution of shock-accelerated heavy-gas cylinder surrounded by the air with different Atwood numbers (A_t=0.28, 0.50, 0.63) is investigated, concentrating on shock focusing and jet formation. Experimentally, a soap film technique is used to generate an ideal two-dimensional discontinuous gas cylinder with a clear surface, which can guarantee the observation of shock wave movements inside the cylinder. Different Atwood numbers are realized by different mixing ratios of SF_6 and air inside the cylinder. A high-speed schlieren system is adopted to capture the shock motions and jet morphology. Numerical simulations are also performed to provide more information. The results indicate that an inward jet is formed for low Atwood numbers, while an outward jet is generated for high Atwood numbers. Different Atwood numbers will lead to the differences in the relative velocities between the incident shock and the refraction shock, which ultimately results in the differences in shock competition near the downstream pole. The morphology and feature of the jet are closely associated with the position and intensity of shock focusing. The pressure and vorticity contours indicate that the jet formation should be attributed to the pressure pulsation caused by shock focusing, and the jet development is ascribed to the vorticity induction. Finally, a time ratio proposed in the previous work for determining the shock-focusing type is verified by experiments.

  15. Biomass shock pretreatment

    Science.gov (United States)

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  16. Inhomogeneous compact extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Bronnikov, K.A. [Center of Gravity and Fundamental Metrology, VNIIMS, 46 Ozyornaya st., Moscow 119361 (Russian Federation); Budaev, R.I.; Grobov, A.V.; Dmitriev, A.E.; Rubin, Sergey G., E-mail: kb20@yandex.ru, E-mail: buday48@mail.ru, E-mail: alexey.grobov@gmail.com, E-mail: alexdintras@mail.ru, E-mail: sergeirubin@list.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow (Russian Federation)

    2017-10-01

    We show that an inhomogeneous compact extra space possesses two necessary features— their existence does not contradict the observable value of the cosmological constant Λ{sub 4} in pure f ( R ) theory, and the extra dimensions are stable relative to the 'radion mode' of perturbations, the only mode considered. For a two-dimensional extra space, both analytical and numerical solutions for the metric are found, able to provide a zero or arbitrarily small Λ{sub 4}. A no-go theorem has also been proved, that maximally symmetric compact extra spaces are inconsistent with 4D Minkowski space in the framework of pure f ( R ) gravity.

  17. Discrimation among different kind of surface defects on Compact Discs

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Wickerhauser, M.V.

    2003-01-01

    Compact Disc players have problems playing discs with surface defects such as scratches and finger prints. The problem is that handling normal disturbances such as mechanical shocks etc, require a high bandwidth of the controllers which keep the Optical Pick-Up focused and radial tracked on the i......Compact Disc players have problems playing discs with surface defects such as scratches and finger prints. The problem is that handling normal disturbances such as mechanical shocks etc, require a high bandwidth of the controllers which keep the Optical Pick-Up focused and radial tracked...... on the information track on the disc. In order for the controllers to handle the surface defects it is required that they are non-sensitive to the frequency contents of the defect, since a defect can be viewed as a disturbance on the measurements. A simple solution to this problem is to decrease the controller...

  18. Relativistic Shock Acceleration

    International Nuclear Information System (INIS)

    Duffy, P.; Downes, T.P.; Gallant, Y.A.; Kirk, J.G.

    1999-01-01

    In this paper we briefly review the basic theory of shock waves in relativistic hydrodynamics and magneto-hydrodynamics, emphasising some astrophysically interesting cases. We then present an overview of the theory of particle acceleration at such shocks describing the methods used to calculate the spectral indices of energetic particles. Recent results on acceleration at ultra-relativistic shocks are discussed. (author)

  19. Advances in compact proton spectrometers for inertial-confinement fusion and plasma nuclear science.

    Science.gov (United States)

    Seguin, F H; Sinenian, N; Rosenberg, M; Zylstra, A; Manuel, M J-E; Sio, H; Waugh, C; Rinderknecht, H G; Johnson, M Gatu; Frenje, J; Li, C K; Petrasso, R; Sangster, T C; Roberts, S

    2012-10-01

    Compact wedge-range-filter proton spectrometers cover proton energies ∼3-20 MeV. They have been used at the OMEGA laser facility for more than a decade for measuring spectra of primary D(3)He protons in D(3)He implosions, secondary D(3)He protons in DD implosions, and ablator protons in DT implosions; they are now being used also at the National Ignition Facility. The spectra are used to determine proton yields, shell areal density at shock-bang time and compression-bang time, fuel areal density, and implosion symmetry. There have been changes in fabrication and in analysis algorithms, resulting in a wider energy range, better accuracy and precision, and better robustness for survivability with indirect-drive inertial-confinement-fusion experiments.

  20. Spectrometers for compact neutron sources

    Science.gov (United States)

    Voigt, J.; Böhm, S.; Dabruck, J. P.; Rücker, U.; Gutberlet, T.; Brückel, T.

    2018-03-01

    We discuss the potential for neutron spectrometers at novel accelerator driven compact neutron sources. Such a High Brilliance Source (HBS) relies on low energy nuclear reactions, which enable cryogenic moderators in very close proximity to the target and neutron optics at comparably short distances from the moderator compared to existing sources. While the first effect aims at increasing the phase space density of a moderator, the second allows the extraction of a large phase space volume, which is typically requested for spectrometer applications. We find that competitive spectrometers can be realized if (a) the neutron production rate can be synchronized with the experiment repetition rate and (b) the emission characteristics of the moderator can be matched to the phase space requirements of the experiment. MCNP simulations for protons or deuterons on a Beryllium target with a suitable target/moderator design yield a source brightness, from which we calculate the sample fluxes by phase space considerations for different types of spectrometers. These match closely the figures of todays spectrometers at medium flux sources. Hence we conclude that compact neutron sources might be a viable option for next generation neutron sources.

  1. Constrained reaction volume approach for studying chemical kinetics behind reflected shock waves

    KAUST Repository

    Hanson, Ronald K.; Pang, Genny A.; Chakraborty, Sreyashi; Ren, Wei; Wang, Shengkai; Davidson, David Frank

    2013-01-01

    We report a constrained-reaction-volume strategy for conducting kinetics experiments behind reflected shock waves, achieved in the present work by staged filling in a shock tube. Using hydrogen-oxygen ignition experiments as an example, we

  2. Prescribing patterns of hydrocortisone in septic shock: a single-center experience of how surviving sepsis guidelines are interpreted and translated into bedside practice.

    Science.gov (United States)

    Contrael, Katlynd M; Killian, Alley J; Gregg, Sara R; Buchman, Timothy G; Coopersmith, Craig M

    2013-10-01

    The Surviving Sepsis Campaign suggests giving hydrocortisone to septic patients only if their "blood pressure is poorly responsive to fluid resuscitation and vasopressor therapy." Because the definition of "poorly responsive" is not provided, the purpose of this study was to identify prescribing triggers for hydrocortisone in septic shock. Retrospective chart review of patients with septic shock over 17 months, who received hydrocortisone, followed by a survey of all intensivists who attended in the study ICUs to determine whether provider attitudes matched clinical practice. Eight ICUs in an academic hospital and a hybrid academic/community hospital. A total of 155 patients with septic shock in whom vasopressors were initiated and hydrocortisone was prescribed. Ninety-nine patients (64%) were already receiving two vasopressors before hydrocortisone was prescribed. An additional 22 patients were on a single high-dose vasopressor prior to corticosteroid initiation. Of patients who survived to have their hydrocortisone dose changed, 57% had their corticosteroids tapered, whereas 43% were abruptly discontinued. Seventy-six percent of patients were no longer on vasopressors when the first dosing change was made. Twenty-seven out of 36 intensivists (75%) completed the survey. The majority (72%) defined "poorly responsive to vasopressors" as the presence of two vasopressors, and 70% stated that they required patients to be off vasopressors prior to altering the corticosteroid dose. Significant variability exists when corticosteroids are prescribed for septic shock, with the most common interpretation in our institution of "poorly responsive to fluid resuscitation and vasopressor therapy" being the presence of two vasopressors. The method and timing of corticosteroid discontinuation also differed among providers. Self-described prescribing patterns from intensivists closely matched their actual behavior, suggesting variability is due to differing interpretations of the

  3. Discrete Element Simulation of Elastoplastic Shock Wave Propagation in Spherical Particles

    Directory of Open Access Journals (Sweden)

    M. Shoaib

    2011-01-01

    Full Text Available Elastoplastic shock wave propagation in a one-dimensional assembly of spherical metal particles is presented by extending well-established quasistatic compaction models. The compaction process is modeled by a discrete element method while using elastic and plastic loading, elastic unloading, and adhesion at contacts with typical dynamic loading parameters. Of particular interest is to study the development of the elastoplastic shock wave, its propagation, and reflection during entire loading process. Simulation results yield information on contact behavior, velocity, and deformation of particles during dynamic loading. Effects of shock wave propagation on loading parameters are also discussed. The elastoplastic shock propagation in granular material has many practical applications including the high-velocity compaction of particulate material.

  4. The VELOCE pulsed power generator for isentropic compression experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Tommy [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Asay, James Russell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Chantrenne, Sophie J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Hickman, Randall John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Willis, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Shay, Andrew W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Grine-Jones, Suzi A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Hall, Clint Allen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dynamic Material Properties; Baer, Melvin R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Engineering Sciences Center

    2007-12-01

    Veloce is a medium-voltage, high-current, compact pulsed power generator developed for isentropic and shock compression experiments. Because of its increased availability and ease of operation, Veloce is well suited for studying isentropic compression experiments (ICE) in much greater detail than previously allowed with larger pulsed power machines such as the Z accelerator. Since the compact pulsed power technology used for dynamic material experiments has not been previously used, it is necessary to examine several key issues to ensure that accurate results are obtained. In the present experiments, issues such as panel and sample preparation, uniformity of loading, and edge effects were extensively examined. In addition, magnetohydrodynamic (MHD) simulations using the ALEGRA code were performed to interpret the experimental results and to design improved sample/panel configurations. Examples of recent ICE studies on aluminum are presented.

  5. Characterization of ceramic powder compacts

    International Nuclear Information System (INIS)

    Yanai, K.; Ishimoto, S.; Kubo, T.; Ito, K.; Ishikawa, T.; Hayashi, H.

    1995-01-01

    UO 2 and Al 2 O 3 powder packing structures in cylindrical powder compacts are observed by scanning electron microscopy using polished cross sections of compacts fixed by low viscosity epoxy resin. Hard aggregates which are not destroyed during powder compaction are observed in some of the UO 2 powder compacts. A technique to measure local density in powder compacts is developed based on counting characteristic X-ray intensity by energy dispersive X-ray analysis (EDX). The local density of the corner portion of the powder compact fabricated by double-acting dry press is higher than that of the inner portion. ((orig.))

  6. Shock waves and shock tubes; Proceedings of the Fifteenth International Symposium, Berkeley, CA, July 28-August 2, 1985

    International Nuclear Information System (INIS)

    Bershader, D.; Hanson, R.

    1986-01-01

    A detailed survey is presented of shock tube experiments, theoretical developments, and applications being carried out worldwide. The discussions explore shock tube physics and the related chemical, physical and biological science and technology. Extensive attention is devoted to shock wave phenomena in dusty gases and other multiphase and heterogeneous systems, including chemically reactive mixtures. Consideration is given to techniques for measuring, visualizing and theoretically modeling flowfield, shock wave and rarefaction wave characteristics. Numerical modeling is explored in terms of the application of computational fluid dynamics techniques to describing flowfields in shock tubes. Shock interactions and propagation, in both solids, fluids, gases and mixed media are investigated, along with the behavior of shocks in condensed matter. Finally, chemical reactions that are initiated as the result of passage of a shock wave are discussed, together with methods of controlling the evolution of laminar separated flows at concave corners on advanced reentry vehicles

  7. Shock Initiation of Damaged Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, S K; Vandersall, K S; Tarver, C M

    2009-10-22

    Explosive and propellant charges are subjected to various mechanical and thermal insults that can increase their sensitivity over the course of their lifetimes. To quantify this effect, shock initiation experiments were performed on mechanically and thermally damaged LX-04 (85% HMX, 15% Viton by weight) and PBX 9502 (95% TATB, 5% Kel-F by weight) to obtain in-situ manganin pressure gauge data and run distances to detonation at various shock pressures. We report the behavior of the HMX-based explosive LX-04 that was damaged mechanically by applying a compressive load of 600 psi for 20,000 cycles, thus creating many small narrow cracks, or by cutting wedge shaped parts that were then loosely reassembled, thus creating a few large cracks. The thermally damaged LX-04 charges were heated to 190 C for long enough for the beta to delta solid - solid phase transition to occur, and then cooled to ambient temperature. Mechanically damaged LX-04 exhibited only slightly increased shock sensitivity, while thermally damaged LX-04 was much more shock sensitive. Similarly, the insensitive explosive PBX 9502 was mechanically damaged using the same two techniques. Since PBX 9502 does not undergo a solid - solid phase transition but does undergo irreversible or 'rachet' growth when thermally cycled, thermal damage to PBX 9502 was induced by this procedure. As for LX-04, the thermally damaged PBX 9502 demonstrated a greater shock sensitivity than mechanically damaged PBX 9502. The Ignition and Growth reactive flow model calculated the increased sensitivities by igniting more damaged LX-04 and PBX 9502 near the shock front based on the measured densities (porosities) of the damaged charges.

  8. Low upper-shelf toughness, high transition temperature test insert in HSST [Heavy Section Steel Technology] PTSE-2 [Pressurized Thermal Shock Experiment-2] vessel and wide plate test specimens: Final report

    International Nuclear Information System (INIS)

    Domian, H.A.

    1987-02-01

    A piece of A387, Grade 22 Class 2 (2-1/4 Cr - 1 Mo) steel plate specially heat treated to produce low upper-shelf (LUS) toughness and high transition temperature was installed in the side wall of Heavy Section Steel Technology (HHST) vessel V-8. This vessel is to be tested by the Oak Ridge National Laboratory (ORNL) in the Pressurized Thermal Shock Experiment-2 (PTSE-2) project of the HSST program. Comparable pieces of the plate were made into six wide plate specimens and other samples. These samples underwent tensile tests, Charpy tests, and J-integral tests. The results of these tests are given in this report

  9. Acceleration of a compact torus

    International Nuclear Information System (INIS)

    Hartmann, C.W.; Eddleman, J.L.; Hammer, J.H.; Kusse, B.

    1987-01-01

    The authors report the first results of a study of acceleration of spheromak-type compact toruses in the RACE experiment (plasma Ring ACceleration Experiment). The RACE apparatus consists of (1) a magnetized, coaxial plasma gun 50 cm long, 35 cm OD, 20 cm ID, (2) 600 cm long coaxial acceleration electrodes 50 cm OD, 20 cm ID, (3) a 250 kJ electrolytic capacitor bank to drive the gun solenoid for initial magnetization, (4) a 200 kJ gun bank, (5) a 260 kJ accelerator bank, and (6) magnetic probes and other diagnostics, and vacuum apparatus. To outer acceleration electrode is an extension, at larger OD, of the gun outer electrode, and the inner acceleration electrode is supported and fed by a coaxial insert in the gun center electrode as shown

  10. Ultra-high gradient compact accelerator developments

    NARCIS (Netherlands)

    Brussaard, G.J.H.; Wiel, van der M.J.

    2004-01-01

    Continued development of relatively compact, although not quite 'table-top', lasers with peak powers in the range up to 100 TW has enabled laser-plasma-based acceleration experiments with amazing gradients of up to 1 TV/m. In order to usefully apply such gradients to 'controlled' acceleration,

  11. Alfven shock trains

    International Nuclear Information System (INIS)

    Malkov, M.A.; Kennel, C.F.; Wu, C.C.; Pellat, R.; Shapiro, V.D.

    1991-01-01

    The Cohen--Kulsrud--Burgers equation (CKB) is used to consider the nonlinear evolution of resistive, quasiparallel Alfven waves subject to a long-wavelength, plane-polarized, monochromatic instability. The instability saturates by nonlinear steepening, which proceeds until the periodic waveform develops an interior scale length comparable to the dissipation length; a fast or an intermediate shock then forms. The result is a periodic train of Alfven shocks of one or the other type. For propagation strictly parallel to the magnetic field, there will be two shocks per instability wavelength. Numerical integration of the time-dependent CKB equation shows that an initial, small-amplitude growing wave asymptotes to a stable, periodic stationary wave whose analytic solution specifies how the type of shock embedded in the shock train, and the amplitude and speed of the shock train, depend on the strength and phase of the instability. Waveforms observed upstream of the Earth's bowshock and cometary shocks resemble those calculated here

  12. Sticker Shock

    Science.gov (United States)

    Schueler, Beth E.; West, Martin R.

    2016-01-01

    This study examines the role of information in shaping public opinion in the context of support for education spending. While there is broad public support for increasing government funding for public schools, Americans tend to underestimate what is currently spent. We embed a series of experiments in a nationally representative survey administered in 2012 (n = 2,993) to examine whether informing citizens about current levels of education spending alters public opinion about whether funding should increase. Providing information on per-pupil spending in a respondent’s local school district reduces the probability that he or she will express support for increasing spending by 22 percentage points on average. Informing respondents about state-average teacher salaries similarly depresses support for salary increases. These effects are larger among respondents who underestimate per-pupil spending and teacher salaries by a greater amount, consistent with the idea that the observed changes in opinion are driven, at least in part, by informational effects, as opposed to priming alone. PMID:27257308

  13. Numerical study of multiscale compaction-initiated detonation

    Science.gov (United States)

    Gambino, J. R.; Schwendeman, D. W.; Kapila, A. K.

    2018-02-01

    A multiscale model of heterogeneous condensed-phase explosives is examined computationally to determine the course of transient events following the application of a piston-driven stimulus. The model is a modified version of that introduced by Gonthier (Combust Sci Technol 175(9):1679-1709, 2003. https://doi.org/10.1080/00102200302373) in which the explosive is treated as a porous, compacting medium at the macro-scale and a collection of closely packed spherical grains capable of undergoing reaction and diffusive heat transfer at the meso-scale. A separate continuum description is ascribed to each scale, and the two scales are coupled together in an energetically consistent manner. Following piston-induced compaction, localized energy deposition at the sites of intergranular contact creates hot spots where reaction begins preferentially. Reaction progress at the macro-scale is determined by the spatial average of that at the grain scale. A parametric study shows that combustion at the macro-scale produces an unsteady detonation with a cyclical character, in which the lead shock loses strength and is overtaken by a stronger secondary shock generated in the partially reacted material behind it. The secondary shock in turn becomes the new lead shock and the process repeats itself.

  14. Adaptive Feature Based Control of Compact Disk Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Vidal, Enrique Sanchez

    2005-01-01

    Many have experienced the problem that their Compact Disc players have difficulties playing Compact Discs with surface faults like scratches and fingerprints. The cause of this is due to the two servo control loops used to keep the Optical Pick-up Unit focused and radially on the information track...... of the Compact Disc. The problem is to design servo controllers which are well suited for handling surface faults which disturb the position measurement and still react sufficiently against normal disturbances like mechanical shocks. In previous work of the same authors a feature based control scheme for CD......-players playing CDs with surface fault is derived and described. This feature based control scheme uses precomputed base to remove the surface fault influence from the position measurements. In this paper an adaptive version of the feature based control scheme is proposed and described. This adaptive scheme can...

  15. Comparison of Hydrocode Simulations with Measured Shock Wave Velocities

    International Nuclear Information System (INIS)

    Hixson, R. S.; Veeser, L. R.

    2014-01-01

    We have conducted detailed 1- and 2-dimensional hydrodynamics calculations to assess the quality of simulations commonly made to understand various shock processes in a sample and to design shock experiments. We began with relatively simple shock experiments, where we examined the effects of the equation of state and the viscoplastic strength models. Eventually we included spallation in copper and iron and a solid-solid phase transformation in iron to assess the quality of the damage and phase transformation simulations.

  16. Weakly compact operators and interpolation

    OpenAIRE

    Maligranda, Lech

    1992-01-01

    The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...

  17. System Shock: The Archetype of Operational Shock

    Science.gov (United States)

    2017-05-25

    the battle space. They can also facilitate a much greater understanding of the variables involved in each party’s decision - making process. However...system shock nests within current US Army Unified Land Operations doctrine. In order to test the utility of system shock theory to Gray Zone...23 Neil E. Harrison, “Thinking about the World We Make ” in Chaos Theory in the Social Sciences: Foundations and Applications

  18. Shock formation within sonoluminescence bubbles

    International Nuclear Information System (INIS)

    Vuong, V.Q.; Szeri, A.J.; Young, D.A.

    1999-01-01

    A strong case has been made by several authors that sharp, spherically symmetric shocks converging on the center of a spherical bubble driven by a strong acoustic field give rise to rapid compression and heating that produces the brief flash of light known as sonoluminescence. The formation of such shocks is considered. It is found that, although at the main collapse the bubble wall does indeed launch an inwardly-traveling compression wave, and although the subsequent reflection of the wave at the bubble center produces a very rapid temperature peak, the wave is prevented from steepening into a sharp shock by an adverse gradient in the sound speed caused by heat transfer. It is shown that the mathematical characteristics of the flow can be prevented from accumulating into a shock front by this adverse sound speed gradient. A range of results is presented for a variety of bubble ambient radii and sound field amplitudes suggested by experiments. The time scale of the peak temperature in the bubble is set by the dynamics of the compression wave: this is typically in the range 100 - 300 ps (FWHM) in concert with recent measurements of the sonoluminescence pulse width. copyright 1999 American Institute of Physics

  19. Use of the Impella Device for Acute Coronary Syndrome Complicated by Cardiogenic Shock - Experience From a Single Heart Center With Analysis of Long-term Mortality.

    Science.gov (United States)

    Schroeter, Marco Robin; Köhler, Herdis; Wachter, Astrid; Bleckmann, Annalen; Hasenfuß, Gerd; Schillinger, Wolfgang

    2016-12-01

    Impella is a microaxial rotary pump that is placed across the aortic valve to expel aspirated blood from the left ventricle into the ascending aorta; it can be used in cardiogenic shock. While previous studies have evaluated the efficacy and safety of the Impella device, more clinically relevant data are necessary, especially with regard to outcomes. We screened our database of Impella patients in our heart center and found 68 consecutive patients who underwent Impella implantation due to acute coronary syndrome (ACS) complicated by cardiogenic shock. Data were evaluated with regard to baseline and procedural characteristics and also included an assessment of the short-term and long-term outcomes. The majority of patients (74%) suffered from an ST-elevation myocardial infarction, and 59% of patients received the Impella device during the initial coronary angiography. In the remaining cases, Impella implantation was performed at a later time, most commonly after IABP implantation. Patient characteristics were not significantly different between both groups. The predominantly implanted device was an Impella 2.5. Mortality in the severely ill patient population remained high, but univariate/multivariate analyses identified significant risk factors. Interestingly, delayed initiation of Impella support was an independent predictor of higher long-term mortality (hazard ratio, 2.157; P=.04) within the Impella patient cohort. This large series of patients with ACS complicated by cardiogenic shock who underwent Impella implantation provides information on the relevant risk factors for mortality. Early (compared with delayed) initiation of Impella support was a predictor of improved survival in this population of patients.

  20. Compact stellarators as reactors

    International Nuclear Information System (INIS)

    Lyon, J.F.; Valanju, P.; Zarnstorff, M.C.; Hirshman, S.; Spong, D.A.; Strickler, D.; Williamson, D.E.; Ware, A.

    2001-01-01

    Two types of compact stellarators are examined as reactors: two- and three-field-period (M=2 and 3) quasi-axisymmetric devices with volume-average =4-5% and M=2 and 3 quasi-poloidal devices with =10-15%. These low-aspect-ratio stellarator-tokamak hybrids differ from conventional stellarators in their use of the plasma-generated bootstrap current to supplement the poloidal field from external coils. Using the ARIES-AT model with B max =12T on the coils gives Compact Stellarator reactors with R=7.3-8.2m, a factor of 2-3 smaller R than other stellarator reactors for the same assumptions, and neutron wall loadings up to 3.7MWm -2 . (author)

  1. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  2. Compact fusion reactors

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  3. Compact nuclear fuel storage

    International Nuclear Information System (INIS)

    Kiselev, V.V.; Churakov, Yu.A.; Danchenko, Yu.V.; Bylkin, B.K.; Tsvetkov, S.V.

    1983-01-01

    Different constructions of racks for compact storage of spent fuel assemblies (FA) in ''coolin''g pools (CP) of NPPs with the BWR and PWR type reactors are described. Problems concerning nuclear and radiation safety and provision of necessary thermal conditions arising in such rack design are discussed. It is concluded that the problem of prolonged fuel storage at NPPs became Very actual for many countries because of retapdation of the rates of fuel reprocessing centers building. Application of compact storage racks is a promising solution of the problem of intermediate FA storage at NPPs. Such racks of stainless boron steel and with neutron absorbers in the from of boron carbide panels enable to increase the capacity of the present CP 2-2.6 times, and the period of FA storage in them up to 5-10 years

  4. Analysis of laboratory compaction methods of roller compacted concrete

    Science.gov (United States)

    Trtík, Tomáš; Chylík, Roman; Bílý, Petr; Fládr, Josef

    2017-09-01

    Roller-Compacted Concrete (RCC) is an ordinary concrete poured and compacted with machines typically used for laying of asphalt road layers. One of the problems connected with this technology is preparation of representative samples in the laboratory. The aim of this work was to analyse two methods of preparation of RCC laboratory samples with bulk density as the comparative parameter. The first method used dynamic compaction by pneumatic hammer. The second method of compaction had a static character. The specimens were loaded by precisely defined force in laboratory loading machine to create the same conditions as during static rolling (in the Czech Republic, only static rolling is commonly used). Bulk densities obtained by the two compaction methods were compared with core drills extracted from real RCC structure. The results have shown that the samples produced by pneumatic hammer tend to overestimate the bulk density of the material. For both compaction methods, immediate bearing index test was performed to verify the quality of compaction. A fundamental difference between static and dynamic compaction was identified. In static compaction, initial resistance to penetration of the mandrel was higher, after exceeding certain limit the resistance was constant. This means that the samples were well compacted just on the surface. Specimens made by pneumatic hammer actively resisted throughout the test, the whole volume was uniformly compacted.

  5. Subject-specific cardiovascular system model-based identification and diagnosis of septic shock with a minimally invasive data set: animal experiments and proof of concept

    International Nuclear Information System (INIS)

    Geoffrey Chase, J; Starfinger, Christina; Hann, Christopher E; Lambermont, Bernard; Ghuysen, Alexandre; Kolh, Philippe; Dauby, Pierre C; Desaive, Thomas; Shaw, Geoffrey M

    2011-01-01

    A cardiovascular system (CVS) model and parameter identification method have previously been validated for identifying different cardiac and circulatory dysfunctions in simulation and using porcine models of pulmonary embolism, hypovolemia with PEEP titrations and induced endotoxic shock. However, these studies required both left and right heart catheters to collect the data required for subject-specific monitoring and diagnosis—a maximally invasive data set in a critical care setting although it does occur in practice. Hence, use of this model-based diagnostic would require significant additional invasive sensors for some subjects, which is unacceptable in some, if not all, cases. The main goal of this study is to prove the concept of using only measurements from one side of the heart (right) in a 'minimal' data set to identify an effective patient-specific model that can capture key clinical trends in endotoxic shock. This research extends existing methods to a reduced and minimal data set requiring only a single catheter and reducing the risk of infection and other complications—a very common, typical situation in critical care patients, particularly after cardiac surgery. The extended methods and assumptions that found it are developed and presented in a case study for the patient-specific parameter identification of pig-specific parameters in an animal model of induced endotoxic shock. This case study is used to define the impact of this minimal data set on the quality and accuracy of the model application for monitoring, detecting and diagnosing septic shock. Six anesthetized healthy pigs weighing 20–30 kg received a 0.5 mg kg −1 endotoxin infusion over a period of 30 min from T0 to T30. For this research, only right heart measurements were obtained. Errors for the identified model are within 8% when the model is identified from data, re-simulated and then compared to the experimentally measured data, including measurements not used in the

  6. Measuring resilience to energy shocks

    OpenAIRE

    Molyneaux, Lynette; Brown, Colin; Foster, John; Wagner, Liam

    2015-01-01

    Measuring energy security or resilience in energy is, in the main, confined to indicators which are used for comparative purposes or to show trends rather than provide empirical evidence of resilience to unpredicted crises. In this paper, the electricity systems of the individual states within the United States of America are analysed for their response to the 1973-1982 and the 2003-2012 oil price shocks. Empirical evidence is sought for elements which are present in systems that experience r...

  7. Compact nuclear reactor

    International Nuclear Information System (INIS)

    Juric, S.I.

    1975-01-01

    A compact nuclear reactor of the pressurized-water variety is described which has two separate parts separably engageable for ease of inspection, maintenance and repair. One of the parts is a pressure vessel having an active core and the other of the parts is a closure adapted on its lower surface with an integral steam generator. An integral pump, external pressurizer and control rods are provided which communicate with the active core when engaged to form a total unit. (U.S.)

  8. Compact power reactor

    International Nuclear Information System (INIS)

    Wetch, J.R.; Dieckamp, H.M.; Wilson, L.A.

    1978-01-01

    There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector

  9. Compact Information Representations

    Science.gov (United States)

    2016-08-02

    Department of Defense, Executive Services, Directorate (0704-0188).   Respondents should be aware that notwithstanding any other provision of law, no person...which lies in the mission of AFOSR. 15.  SUBJECT TERMS sparse sampling , principal components analysis 16.  SECURITY CLASSIFICATION OF: 17...approved for public release Contents 1 Training for Ph.D. Students and Postdoc Researchers 2 2 Papers 2 3 Summary of Proposed Research: Compact

  10. Holographic interferometric observation of shock wave focusing to extracorporeal shock wave lithotripsy

    Science.gov (United States)

    Takayama, Kazuyoshi; Obara, Tetsuro; Onodera, Osamu

    1991-04-01

    Underwater shock wave focusing is successfully applied to disintegrate and remove kidney stones or gallbladder stones without using surgical operations. This treatment is one of the most peaceful applications ofshock waves and is named as the Extracorporeal Shock Wave Lithotripsy. Ajoint research project is going on between the Institute ofFluid Science, Tohoku University and the School ofMedicine, Tohoku University. The paper describes a result of the fundamental research on the underwater shock wave focusing applied to the ESWL. Quantitatively to visualize the underwater shock waves, various optical flow visualization techniques were successfully used such as holographic interferometry, and shadowgraphs combined with Ima-Con high speed camera. Double exposure holographic interferometric observation revealed the mechanism of generation, propagation and focusing of underwater shock waves. The result of the present research was already used to manufacture a prototype machine and it has already been applied successfully to ESWL crinical treatments. However, despite of success in the clinical treatments, important fundamental questions still remain unsolved, i.e., effects of underwater shock wave focusing on tissue damage during the treatment. Model experiments were conducted to clarify mechanism of the tissue damage associated with the ESWL. Shock-bubble interactions were found responsible to the tissue damage during the ESWL treatment. In order to interprete experimental findings and to predict shock wave behavior and high pressures, a numerical simulation was carried. The numerical results agreed with the experiments.

  11. Review of compact, alternate concepts for magnetic confinement fusion

    International Nuclear Information System (INIS)

    Nickerson, S.B.; Shmayda, W.T.; Dinner, P.J.; Gierszewski, P.

    1984-06-01

    This report documents a study of compact alternate magnetic confinement fusion experiments and conceptual reactor designs. The purpose of this study is to identify those devices with a potential to burn tritium in the near future. The bulk of the report is made up of a review of the following compact alternates: compact toroids, high power density tokamaks, linear magnetic systems, compact mirrors, reversed field pinches and some miscellaneous concepts. Bumpy toruses and stellarators were initially reviewed but were not pursued since no compact variations were found. Several of the concepts show promise of either burning tritium or evolving into tritium burning devices by the early 1990's: RIGGATRON, Ignitor, OHTE, Frascati Tokamak upgrade, several driven (low or negative net power) mirror experiments and several Reversed Field Pinch experiments that may begin operation around 1990. Of the above only the Frascati Tokamak Upgrade has had funds allocated. Also identified in this report are groups who may have tritium burning experiments in the mid to late 1990's. There is a discussion of the differences between the reviewed devices and the mainline tokamak experiments. This discussion forms the basis of recommendations for R and D aimed at the compact alternates and the applicability of the present CFFTP program to the needs of the compact alternates. These recommendations will be presented in a subsequent report

  12. Modeling compaction-induced energy dissipation of granular HMX

    Energy Technology Data Exchange (ETDEWEB)

    Gonthier, K.A. [Lamar Univ., Beaumont, TX (US). Dept. of Mechanical Engineering; Menikoff, R.; Son, S.F.; Asay, B.W. [Los Alamos National Lab., NM (US)

    1998-12-31

    A thermodynamically consistent model is developed for the compaction of granular solids. The model is an extension of the single phase limit of two-phase continuum models used to describe Deflagration-to-Detonation Transition (DDT) experiments. The focus is on the energetics and dissipation of the compaction process. Changes in volume fraction are partitioned into reversible and irreversible components. Unlike conventional DDT models, the model is applicable from the quasi-static to dynamic compaction regimes for elastic, plastic, or brittle materials. When applied to the compaction of granular HMX (a brittle material), the model predicts results commensurate with experiments including stress relaxation, hysteresis, and energy dissipation. The model provides a suitable starting point for the development of thermal energy localization sub-scale models based on compaction-induced dissipation.

  13. Analytical solutions of hypersonic type IV shock - shock interactions

    Science.gov (United States)

    Frame, Michael John

    An analytical model has been developed to predict the effects of a type IV shock interaction at high Mach numbers. This interaction occurs when an impinging oblique shock wave intersects the most normal portion of a detached bow shock. The flowfield which develops is complicated and contains an embedded jet of supersonic flow, which may be unsteady. The jet impinges on the blunt body surface causing very high pressure and heating loads. Understanding this type of interaction is vital to the designers of cowl lips and leading edges on air- breathing hypersonic vehicles. This analytical model represents the first known attempt at predicting the geometry of the interaction explicitly, without knowing beforehand the jet dimensions, including the length of the transmitted shock where the jet originates. The model uses a hyperbolic equation for the bow shock and by matching mass continuity, flow directions and pressure throughout the flowfield, a prediction of the interaction geometry can be derived. The model has been shown to agree well with the flowfield patterns and properties of experiments and CFD, but the prediction for where the peak pressure is located, and its value, can be significantly in error due to a lack of sophistication in the model of the jet fluid stagnation region. Therefore it is recommended that this region of the flowfield be modeled in more detail and more accurate experimental and CFD measurements be used for validation. However, the analytical model has been shown to be a fast and economic prediction tool, suitable for preliminary design, or for understanding the interactions effects, including the basic physics of the interaction, such as the jet unsteadiness. The model has been used to examine a wide parametric space of possible interactions, including different Mach number, impinging shock strength and location, and cylinder radius. It has also been used to examine the interaction on power-law shaped blunt bodies, a possible candidate for

  14. Compact Intracloud Discharges

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David A. [Univ. of Colorado, Boulder, CO (United States)

    1998-11-01

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackboard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackboard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackboard observations. On two occasions, the ground-based systems and Blackboard even recorded emissions that were produced by the same exact events. From the ground based observations, it has been determined that TIPP events areproduced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDS, an acronym for compact intracloud discharges. During the summer of 1996, ground-based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDS. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDS were recorded from three

  15. Diffusion through statically compacted clay

    International Nuclear Information System (INIS)

    Ho, C.L.; Shebl, M.A.A.

    1994-01-01

    This paper presents experimental work on the effect of compaction on contaminant flow through clay liners. The experimental program included evaluation of soil properties, compaction, permeability and solute diffusion. A permeameter was built of non reactive materials to test samples compacted at different water contents and compactive efforts. The flow of a permeating solute, LiCl, was monitored. Effluent samples were collected for solute concentration measurements. The concentrations were measured by performing atomic adsorption tests. The analyzed results showed different diffusion characteristics when compaction conditions changed. At each compactive effort, permeability decreased as molding water content increased. Consequently, transit time (measured at relative concentration 50%) increased and diffusivity decreased. As compactive effort increased for soils compacted dry of optimum, permeability and diffusion decreased. On the other hand, as compactive effort increased for soils compacted wet of optimum, permeability and diffusivity increased. Tortuosity factor was indirectly measured from the diffusion and retardation rate. Tortuosity factor also decreased as placement water content was increased from dry of optimum to wet of optimum. Then decreases were more pronounced for low compactive effort tests. 27 refs., 7 figs., 5 tabs

  16. Observations of Macroscopic Shocks in the Laboratory

    Science.gov (United States)

    Endrizzi, Douglass; Laufman-Wollitzer, Lauren; Clark, Mike; Olson, Joseph; Myers, Rachel; Forest, Cary; Gota, Hiroshi; WiPAL Team; Tri Alpha Energy Team

    2016-10-01

    A magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy has been installed on the Wisconsin Plasma Astrophysics Lab (WiPAL) vacuum vessel. The MCPG fires a dense (1018m-3) and warm (10-30 eV) compact toroid (CT) at speeds of order 100 km/s. The CT is characterized using B magnetic diagnostics, multi-tip temperature probes, Ion saturation density probes, and a fast Phantom camera. The CT is injected into vacuum field, neutral gas, and plasmas of various beta. Results and evidence for propagating shocks will be presented. This work supported the NSF GRFP under Grant No. DGE-1256259.

  17. Experimental studies of compact toroids

    International Nuclear Information System (INIS)

    1991-01-01

    The Berkeley Compact Toroid Experiment (BCTX) device is a plasma device with a Marshall-gun generated, low aspect ratio toroidal plasma. The device is capable of producing spheromak-type discharges and may, with some modification, produce low-aspect ratio tokamak configurations. A unique aspect of this experimenal devie is its large lower hybrid (LH) heating system, which consists of two 450MHz klystron tubes generating 20 megawatts each into a brambilla-type launching structure. Successful operation with one klystron at virtually full power (18 MW) has been accomplished with 110 μs pulse length. A second klystron is currently installed in its socket and magnet but has not been added to the RF drive system. This report describes current activities and accomplishments and describes the anticipated results of next year's activity

  18. Search For New Physics In The Compact Muon Solenoid (CMS) Experiment And The Response Of The CMS Calorimeters To Particles And Jets

    CERN Document Server

    Gumus, Kazim Ziya

    2008-01-01

    A Monte Carlo study of a generic search for new resonances beyond the Standard Model (SM) in the CMS experiment is presented. The resonances are axigluon, coloron, E6 diquark, excited quark, W', Z', and the Randall-Sundrum graviton which decay to dijets. The dijet resonance cross section that the CMS can expect to discover at a 5s significance or to exclude at 95% confidence level for integrated luminosities of 100 pb-1, 1 fb-1, and 10 fb-1 is evaluated. It is shown that a 5s discovery of a multi-TeV dijet resonance is possible for an axigluon, excited quark, and E6 diquark. However, a 5s discovery can not be projected with confidence for a W', Z' and the Randall-Sundrum graviton. On the other hand, 95% CL exclusion mass regions can be measured for all resonances at high luminosities. In the second part of this dissertation, the analyses of the 2006 test beam data from the combined electromagnetic and hadronic barrel calorimeters are presented. The CMS barrel calorimeters' response to a variety of beam partic...

  19. EAF Slag Aggregate in Roller-Compacted Concrete Pavement: Effects of Delay in Compaction

    Directory of Open Access Journals (Sweden)

    My Ngoc-Tra Lam

    2018-04-01

    Full Text Available This study investigates the effect of delay in compaction on the optimum moisture content and the mechanical propertie s (i.e., compressive strength, ultrasonic pulse velocity, splitting tensile strength, and modulus of elasticity of roller-compacted concrete pavement (RCCP made of electric arc furnace (EAF slag aggregate. EAF slag with size in the range of 4.75–19 mm was used to replace natural coarse aggregate in RCCP mixtures. A new mixing method was proposed for RCCP using EAF slag aggregate. The optimum moisture content of RCCP mixtures in this study was determined by a soil compaction method. The Proctor test assessed the optimum moisture content of mixtures at various time after mixing completion (i.e., 0, 15, 30, 60, and 90 min. Then, the effect of delay in compaction on the mechanical properties of RCCP mixtures at 28 days of age containing EAF slag aggregate was studied. The results presented that the negative effect on water content in the mixture caused by the higher water absorption characteristic of EAF slag was mitigated by the new mixing method. The optimum water content and maximum dry density of RCCP experience almost no effect from the delay in compaction. The compressive strength and splitting tensile strength of RCCP using EAF slag aggregate fulfilled the strength requirements for pavement with 90 min of delay in compaction.

  20. Means, methods and performances of the AREVA's HTR compact controls

    International Nuclear Information System (INIS)

    Banchet, J.; Guillermier, P.; Tisseur, D.; Vitali, M. P.

    2008-01-01

    In the AREVA's HTR development program, the reactor plant is composed of a prismatic core containing graphite cylindrical fuel elements, called compacts, where TRISO particles are dispersed. Starting from its past compacting process, the latter being revamped through the use of state of the art equipments, CERCA, 100% AREVA NP's subsidiary, was able to recover the quality of past compacts production. The recovered compacting process is composed of the following manufacturing steps: graphite matrix granulation, mix between the obtained granulates and particles, compacting and calcining at low pressure and temperature. To adapt this past process to new manufacturing equipments, non destructive examination tests were carried out to assess the compact quality, the latter being assessed via in house developed equipments and methods at each step of the design of experiments. As for the manufacturing process, past quality control methods were revamped to measure compact dimensional features (diameter, perpendicularity and cone effect), visual aspect, SiC layer failure fraction (via anodic disintegration and burn leach test) and homogeneity via 2D radiography coupled to ceramography. Although meeting quality requirements, 2D radiography method could not provide a quantified specification for compact homogeneity characterization. This limitation yielded the replacement of this past technique by a method based on X-Ray tomography. Development was conducted on this new technique to enable the definition of a criterion to quantify compact homogeneity, as well as to provide information about the distances in between particles. This study also included a comparison between simulated and real compacts to evaluate the accuracy of the technique as well as the influence of particle packing fraction on compact homogeneity. The developed quality control methods and equipments guided the choices of manufacturing parameters adjustments at the development stage and are now applied for

  1. EXPLOSIVE COMPACTION OF CLAD GRAPHITE POWDERS AND OBTAINING OF COATINGS ON THEIR BASE

    Energy Technology Data Exchange (ETDEWEB)

    A. B. PEIKRISHIVILI; ET AL

    2000-11-01

    In order to consolidate graphite based powders and in order to obtain coatings with density values near to the theoretical ones clad graphite powders of the C{sub graphite} - Ni (C{sub g} - Ni) compositions were explosively compacted under different loading conditions. Theoretical calculations revealed that for assessing the stress-deformed state of C{sub g} - Ni compositions and computing the normal and tangent stress components (when V{sub D} < C{sub longitudinal} and V{sub D} < C{sub transversal}) it is recommended to apply the dynamic problem's solution model while the pressure impulse P = f(x) is being uniformly spread with constant rate along the boundary of a semi-infinite elastic body. The results of our experiments showed that it is possible to obtain high dense coatings from C{sub g}-Ni compositions bonded by an intermediate layer to the substrate material. The structure and properties of the coatings depends on the intensity of the shock loading and temperature. The effect of the shock loading conditions (temperature, loading intensity) on the structure, properties and structure/properties relationships for the C{sub g} - Ni coatings are discussed.

  2. How do health workers experience and cope with shocks? Learning from four fragile and conflict-affected health systems in Uganda, Sierra Leone, Zimbabwe and Cambodia.

    Science.gov (United States)

    Witter, Sophie; Wurie, Haja; Chandiwana, Pamela; Namakula, Justine; So, Sovannarith; Alonso-Garbayo, Alvaro; Ssengooba, Freddie; Raven, Joanna

    2017-11-01

    This article is grounded in a research programme which set out to understand how to rebuild health systems post-conflict. Four countries were studied-Uganda, Sierra Leone, Zimbabwe and Cambodia-which were at different distances from conflict and crisis, as well as having unique conflict stories. During the research process, the Ebola epidemic broke out in West Africa. Zimbabwe has continued to face a profound economic crisis. Within our research on health worker incentives, we captured insights from 128 life histories and in-depth interviews with a variety of staff that had remained in service. This article aims to draw together lessons from these contexts which can provide lessons for enhancing staff and therefore health system resilience in future, especially in similarly fragile and conflict-affected contexts. We examine the reported effects, both personal and professional, of the three different types of shock (conflicts, epidemics and prolonged political-economic crises), and how staff coped. We find that the impact of shocks and coping strategies are similar between conflict/post-conflict and epidemic contexts-particularly in relation to physical threats and psychosocial threats-while all three contexts create challenges and staff responses for working conditions and remuneration. Health staff showed considerable inventiveness and resilience, and also benefited from external assistance of various kinds, but there are important gaps which point to ways in which they should be better protected and supported in the future. Health systems are increasingly fragile and conflict-prone, and shocks are often prolonged or repeated. Resilience should not be taken for granted or used as an excuse for abandoning frontline health staff. Strategies should be in place at local, national and international levels to prepare for predictable crises of various sorts, rather than waiting for them to occur and responding belatedly, or relying on personal sacrifices by staff to keep

  3. MECHANICS OF DYNAMIC POWDER COMPACTION PROCESS

    OpenAIRE

    Nurettin YAVUZ

    1996-01-01

    In recent years, interest in dynamic compaction methods of metal powders has increased due to the need to improve compaction properties and to increase production rates of compacts. In this paper, review of dynamic and explosive compaction of metal powders are given. An attempt is made to get a better understanding of the compaction process with the mechanicis of powder compaction.

  4. Computed tomography scanner applied to soil compaction studies

    International Nuclear Information System (INIS)

    Vaz, C.M.P.

    1989-11-01

    The soil compaction problem was studied using a first generation computed tomography scanner (CT). This apparatus gets images of soil cross sections samples, with resolution of a few millimeters. We performed the following laboratory and field experiments: basic experiments of equipment calibrations and resolutions studies; measurements of compacted soil thin layers; measurements of soil compaction caused by agricultural tools; stress-strain modelling in confined soil sample, with several moisture degree; characterizations of soil bulk density profile with samples collected in a hole (trench), comparing with a cone penetrometer technique. (author)

  5. Mechanical and chemical compaction in fine-grained shallow-water limestones.

    Science.gov (United States)

    Shinn, E.A.; Robbin, D.M.

    1983-01-01

    Significant mechanical compaction resulted from pressures simulating less than 305 m of burial. Increasing loads to an equivalent of more than 3400 m did not significantly increase compaction or reduce sediment core length. Chemical compaction (pressure dissolution) was detected only in sediment cores compacted to pressures greater than 3400 m of burial. These short-term experiments suggest that chemical compaction would begin at much shallower depths given geologic time. Compaction experiments that caused chemical compaction lend support to the well-established hypothesis; that cement required to produce a low-porosity/low-permeability fine-grained limestone is derived internally. Dissolution, ion diffusion, and reprecipitation are considered the most likely processes for creating significant thicknesses of dense limestone in the geologic record. Continuation of chemical compaction after significant porosity reduction necessitates expulsion of connate fluids, possibly including hydrocarbons. -from Authors

  6. Compact neutron flux monitor

    International Nuclear Information System (INIS)

    Madhavi, V.; Phatak, P.R.; Bahadur, C.; Bayala, A.K.; Jakati, R.K.; Sathian, V.

    2003-01-01

    Full text: A compact size neutron flux monitor has been developed incorporating standard boards developed for smart radiation monitors. The sensitivity of the monitors is 0.4cps/nV. It has been tested up to 2075 nV flux with standard neutron sources. It shows convincing results even in high flux areas like 6m away from the accelerator in RMC (Parel) for 106/107 nV. These monitors have a focal and remote display, alarm function with potential free contacts for centralized control and additional provision of connectivity via RS485/Ethernet. This paper describes the construction, working and results of the above flux monitor

  7. Compact LINAC for deuterons

    International Nuclear Information System (INIS)

    Kurennoy, S.S.; O'Hara, J.F.; Rybarcyk, L.J.

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  8. Compact electron storage rings

    International Nuclear Information System (INIS)

    Williams, G.P.

    1987-01-01

    There have been many recent developments in the area of compact storage rings. Such rings would have critical wavelengths of typically 10 A, achieved with beam energies of several hundreds of MeV and superconducting dipole fields of around 5 Tesla. Although the primary motivation for progress in this area is that of commercial x-ray lithography, such sources might be an attractive source for college campuses to operate. They would be useful for many programs in materials science, solid state, x-ray microscopy and other biological areas. We discuss the properties of such sources and review developments around the world, primarily in the USA, japan and W. Germany

  9. Compact synchrotron radiation source

    International Nuclear Information System (INIS)

    Liu, N.; Wang, T.; Tian, J.; Lin, Y.; Chen, S.; He, W.; Hu, Y.; Li, Q.

    1985-01-01

    A compact 800 MeV synchrotron radiation source is discussed. The storage ring has a circumference of 30.3 m, two 90 degree and four 45 degree bending magnet sections, two long straight sections and four short straight sections. The radius of the bending magnet is 2.224m. The critical wave length is 24A. The injector is a 15 Mev Microtron Electrons are accelerated from 15 Mev to 800 Mev by ramping the field of the ring. The expected stored current will be around 100 ma

  10. LASL Compact Torus Program

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Bartsch, R.R.

    1981-01-01

    The Compact Torus (CT) concept includes any axisymmetric toroidal plasma configuration, which does not require the linking of any material through the hole in the torus. Thus, the magnet coils, vacuum vessel, etc., have a simple cylindrical or spherical geometry instead of the toroidal geometry required for Tokamaks and RFP's. This simplified geometry results in substantial engineering advantages in CT reactor embodiments while retaining the good confinement properties afforded by an axisymmetric toroidal plasma-field geometry. CT's can be classified into three major types by using the ion gyro radius rho/sub i/ and the magnitude of the maximum toroidal field B/sub tm/

  11. Compact Q-balls

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Losano, L.; Marques, M.A. [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Menezes, R. [Departamento de Ciências Exatas, Universidade Federal da Paraíba, 58297-000 Rio Tinto, PB (Brazil); Departamento de Física, Universidade Federal de Campina Grande, 58109-970 Campina Grande, PB (Brazil); Rocha, R. da [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, 09210-580 Santo André (Brazil)

    2016-07-10

    In this work we deal with non-topological solutions of the Q-ball type in two space–time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  12. The structure of steady shock waves in porous metals

    Science.gov (United States)

    Czarnota, Christophe; Molinari, Alain; Mercier, Sébastien

    2017-10-01

    The paper aims at developing an understanding of steady shock wave propagation in a ductile metallic material containing voids. Porosity is assumed to be less than 0.3 and voids are not connected (foams are not considered). As the shock wave is traveling in the porous medium, the voids are facing a rapid collapse. During this dynamic compaction process, material particles are subjected to very high acceleration in the vicinity of voids, thus generating acceleration forces at the microscale that influence the overall response of the porous material. Analyzing how stationary shocks are influenced by these micro-inertia effects is the main goal of this work. The focus is essentially on the shock structure, ignoring oscillatory motion of pores prevailing at the tail of the shock wave. Following the constitutive framework developed by Molinari and Ravichandran (2004) for the analysis of steady shock waves in dense metals, an analytical approach of steady state propagation of plastic shocks in porous metals is proposed. The initial void size appears as a characteristic internal length that scales the overall dynamic response, thereby contributing to the structuring of the shock front. This key feature is not captured by standard damage models where the porosity stands for the single damage parameter with no contribution of the void size. The results obtained in this work provide a new insight in the fundamental understanding of shock waves in porous media. In particular, a new scaling law relating the shock width to the initial void radius is obtained when micro-inertia effects are significant.

  13. PARTICLE ACCELERATION AT THE HELIOSPHERIC TERMINATION SHOCK WITH A STOCHASTIC SHOCK OBLIQUITY APPROACH

    International Nuclear Information System (INIS)

    Arthur, Aaron D.; Le Roux, Jakobus A.

    2013-01-01

    Observations by the plasma and magnetic field instruments on board the Voyager 2 spacecraft suggest that the termination shock is weak with a compression ratio of ∼2. However, this is contrary to the observations of accelerated particle spectra at the termination shock, where standard diffusive shock acceleration theory predicts a compression ratio closer to ∼2.9. Using our focused transport model, we investigate pickup proton acceleration at a stationary spherical termination shock with a moderately strong compression ratio of 2.8 to include both the subshock and precursor. We show that for the particle energies observed by the Voyager 2 Low Energy Charged Particle (LECP) instrument, pickup protons will have effective length scales of diffusion that are larger than the combined subshock and precursor termination shock structure observed. As a result, the particles will experience a total effective termination shock compression ratio that is larger than values inferred by the plasma and magnetic field instruments for the subshock and similar to the value predicted by diffusive shock acceleration theory. Furthermore, using a stochastically varying magnetic field angle, we are able to qualitatively reproduce the multiple power-law structure observed for the LECP spectra downstream of the termination shock

  14. Hydraulic shock absorbers

    International Nuclear Information System (INIS)

    Thatcher, G.; Davidson, D. F.

    1984-01-01

    A hydraulic shock absorber of the dash pot kind for use with electrically conducting liquid such as sodium, has magnet means for electro magnetically braking a stream of liquid discharged from the cylinder. The shock absorber finds use in a liquid metal cooled nuclear reactor for arresting control rods

  15. Our Favorite Film Shocks

    DEFF Research Database (Denmark)

    Willerslev, Rane; Suhr, Christian

    2014-01-01

    The modern medium of film has long been hailed for its capacity for producing shocks of an entertaining, thought-provoking, or even politically emancipative nature. But what is a shock, how and when does it occur, how long does it last, and are there particular techniques for producing cinematic...

  16. Climate shocks and conflict

    NARCIS (Netherlands)

    Papaioannou, Kostadis J.

    2016-01-01

    This paper offers a historical micro-level analysis of the impact of climate shocks on the incidence of civil conflict in colonial Nigeria (1912-1945). Primary historical sources on court cases, prisoners and homicides are used to capture conflict. To measure climate shocks we use the deviation

  17. Confinement and heating of high beta plasma with emphasis on compact toroids. Compact toroid research

    International Nuclear Information System (INIS)

    Vlases, G.C.; Pietrzyk, Z.A.

    1984-11-01

    Two older projects associated with very high energy density plasmas, specifically the High Density Field Reversed Configuration and the Liner Plasma Compression Experiment, have been completed. Attention has been turned to compact toroid experiments of more conventional density, and three experiments have been initiated. These include the Coaxial Slow Source Experiment, the Variable Length FRC Experiment, and Variable Angle CthetaP Experiment. In each case, the project was begun in order to provide basic plasma physics information on specific unresolved issues of progammatic importance to the national CT Program

  18. Scalable Nonlinear Compact Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Debojyoti [Argonne National Lab. (ANL), Argonne, IL (United States); Constantinescu, Emil M. [Univ. of Chicago, IL (United States); Brown, Jed [Univ. of Colorado, Boulder, CO (United States)

    2014-04-01

    In this work, we focus on compact schemes resulting in tridiagonal systems of equations, specifically the fifth-order CRWENO scheme. We propose a scalable implementation of the nonlinear compact schemes by implementing a parallel tridiagonal solver based on the partitioning/substructuring approach. We use an iterative solver for the reduced system of equations; however, we solve this system to machine zero accuracy to ensure that no parallelization errors are introduced. It is possible to achieve machine-zero convergence with few iterations because of the diagonal dominance of the system. The number of iterations is specified a priori instead of a norm-based exit criterion, and collective communications are avoided. The overall algorithm thus involves only point-to-point communication between neighboring processors. Our implementation of the tridiagonal solver differs from and avoids the drawbacks of past efforts in the following ways: it introduces no parallelization-related approximations (multiprocessor solutions are exactly identical to uniprocessor ones), it involves minimal communication, the mathematical complexity is similar to that of the Thomas algorithm on a single processor, and it does not require any communication and computation scheduling.

  19. Compact magnetic fusion systems

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.

    1983-12-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak/sup 1/ and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics.

  20. Compact magnetic fusion systems

    International Nuclear Information System (INIS)

    Linford, R.K.

    1983-01-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak 1 and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics

  1. Compact Infrasonic Windscreen

    Science.gov (United States)

    Zuckerwar, Allan J.; Shams, Qamar A.; Sealey, Bradley S.; Comeaux, Toby

    2005-01-01

    A compact windscreen has been conceived for a microphone of a type used outdoors to detect atmospheric infrasound from a variety of natural and manmade sources. Wind at the microphone site contaminates received infrasonic signals (defined here as sounds having frequencies <20 Hz), because a microphone cannot distinguish between infrasonic pressures (which propagate at the speed of sound) and convective pressure fluctuations generated by wind turbulence. Hence, success in measurement of outdoor infrasound depends on effective screening of the microphone from the wind. The present compact windscreen is based on a principle: that infrasound at sufficiently large wavelength can penetrate any barrier of practical thickness. Thus, a windscreen having solid, non-porous walls can block convected pressure fluctuations from the wind while transmitting infrasonic acoustic waves. The transmission coefficient depends strongly upon the ratio between the acoustic impedance of the windscreen and that of air. Several materials have been found to have impedance ratios that render them suitable for use in constructing walls that have practical thicknesses and are capable of high transmission of infrasound. These materials (with their impedance ratios in parentheses) are polyurethane foam (222), space shuttle tile material (332), balsa (323), cedar (3,151), and pine (4,713).

  2. Compact electrostatic comb actuator

    Science.gov (United States)

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  3. Development task of compact reactor

    International Nuclear Information System (INIS)

    Kurushima, Morihiro

    1982-01-01

    In the Ministry of International Trade and Industry, studies proceed on the usage of compact medium and small LWRs. As such, the reactors from 100 to 200 MW may meet varieties of demands in scale and kind in view of the saving of petroleum and the economy of nuclear power. In this case, the technology of light water reactors with already established safety will be suitable for the development of compact reactors. The concept of ''nuclear power community'' using the compact reactors in local society and industrial zones was investigated. The following matters are described: need for the introduction of compact reactors, the survey on the compact reactor systems, and the present status and future problems for compact reactor usage. (J.P.N.)

  4. The Rapid Formation of Localized Compaction Bands Under Hydrostatic Load Leading to Pore-pressure Transients in Compacting Rocks

    Science.gov (United States)

    Faulkner, D.; Leclere, H.; Bedford, J. D.; Behnsen, J.; Wheeler, J.

    2017-12-01

    Compaction of porous rocks can occur uniformly or within localized deformation bands. The formation of compaction bands and their effects on deformation behaviour are poorly understood. Porosity may be primary and compaction can occur with burial, or it can be produced by metamorphic reactions with a solid volume reduction, that can then undergo collapse. We report results from hydrostatic compaction experiments on porous bassanite (CaSO4.0.5H2O) aggregates. Gypsum (CaSO4.2H2O) is first dehydrated under low effective pressure, 4 MPa, to produce a bassanite aggregate with a porosity of 27%. Compaction is induced by increasing confining pressure at rates from 0.001 MPa/s to 0.02 MPa/s while the sample is maintained at a temperature of 115°C. At slow compaction rates, porosity collapse proceeds smoothly. At higher compaction rates, sudden increases in the pore-fluid pressure occur with a magnitude of 5 MPa. Microstructural investigations using X-ray microtomography and SEM observations show that randomly oriented localized compaction features occur in all samples, where the bulk porosity of 18% outside the band is reduced to 5% inside the band. Previous work on deformation bands has suggested that localized compactive features only form under an elevated differential stress and not under a hydrostatic stress state. The magnitude of the pore-pressure pulses can be explained by the formation of compaction bands. The results indicate that the compaction bands can form by rapid (unstable) propagation across the sample above a critical strain rate, or quasi-statically at low compaction rates without pore-fluid pressure bursts. The absence of pore-fluid pressure bursts at slow compaction rates can be explained by viscous deformation of the bassanite aggregate around the tip of a propagating compaction band, relaxing stress, and promoting stable propagation. Conversely, at higher compaction rates, viscous deformation cannot relax the stress sufficiently and unstable

  5. Formation of a compact toroid for enhanced efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Mozgovoy, A. G. [P.N. Lebedev Physical Institute, Moscow 119991 (Russian Federation); Romadanov, I. V.; Ryzhkov, S. V., E-mail: ryzhkov@power.bmstu.ru [Bauman Moscow State Technical University, Moscow 105005 (Russian Federation)

    2014-02-15

    We report here our results on the formation of a plasma configuration with the generic name of compact toroid (CT). A method of compact toroid formation to confine, heat and compress a plasma is investigated. Formation of a compact torus using an additional toroidal magnetic field helps to increase the plasma current to a maintainable level of the original magnetic field. We design the Compact Toroid Challenge (CTC) experiment in order to improve the magnetic flux trapping during field reversal in the formation of a compact toroid. The level of the magnetic field immersed in the plasma about 70% of the primary field is achieved. The CTC device and scheme of high level capturing of magnetic flux are presented.

  6. Linear Shrinkage Behaviour of Compacted Loam Masonry Blocks

    Directory of Open Access Journals (Sweden)

    NAWAB ALI LAKHO

    2017-04-01

    Full Text Available Walls of wet loam, used in earthen houses, generally experience more shrinkage which results in cracks and less compressive strength. This paper presents a technique of producing loam masonry blocks that are compacted in drained state during casting process in order to minimize shrinkage. For this purpose, loam masonry blocks were cast and compacted at a pressure of 6 MPa and then dried in shade by covering them in plastic sheet. The results show that linear shrinkage of 2% occurred which is smaller when compared to un-compacted wet loam walls. This implies that the loam masonry blocks compacted in drained state is expected to perform better than un-compacted wet loam walls.

  7. Modelling and Simulation of Tensile Fracture in High Velocity Compacted Metal Powder

    International Nuclear Information System (INIS)

    Jonsen, P.; Haeggblad, H.-A.

    2007-01-01

    In cold uniaxial powder compaction, powder is formed into a desired shape with rigid tools and a die. After pressing, but before sintering, the compacted powder is called green body. A critical property in the metal powder pressing process is the mechanical properties of the green body. Beyond a green body free from defects, desired properties are high strength and uniform density. High velocity compaction (HVC) using a hydraulic operated hammer is a production method to form powder utilizing a shock wave. Pre-alloyed water atomised iron powder has been HVC-formed into circular discs with high densities. The diametral compression test also called the Brazilian disc test is an established method to measure tensile strength in low strength material like e.g. rock, concrete, polymers and ceramics. During the test a thin disc is compressed across the diameter to failure. The compression induces a tensile stress perpendicular to the compressed diameter. In this study the test have been used to study crack initiation and the tensile fracture process of HVC-formed metal powder discs with a relative density of 99%. A fictitious crack model controlled by a stress versus crack-width relationship is utilized to model green body cracking. Tensile strength is used as a failure condition and limits the stress in the fracture interface. The softening rate of the model is obtained from the corresponding rate of the dissipated energy. The deformation of the powder material is modelled with an elastic-plastic Cap model. The characteristics of the tensile fracture development of the central crack in a diametrically loaded specimen is numerically studied with a three dimensional finite element simulation. Results from the finite element simulation of the diametral compression test shows that it is possible to simulate fracturing of HVC-formed powder. Results from the simulation agree reasonably with experiments

  8. Physics of Compact Advanced Stellarators

    International Nuclear Information System (INIS)

    Zarnstorff, M.C.; Berry, L.A.; Brooks, A.; Fredrickson, E.; Fu, G.-Y.; Hirshman, S.; Hudson, S.; Ku, L.-P.; Lazarus, E.; Mikkelsen, D.; Monticello, D.; Neilson, G.H.; Pomphrey, N.; Reiman, A.; Spong, D.; Strickler, D.; Boozer, A.; Cooper, W.A.; Goldston, R.; Hatcher, R.; Isaev, M.; Kessel, C.; Lewandowski, J.; Lyon, J.; Merkel, P.; Mynick, H.; Nelson, B.E.; Nuehrenberg, C.; Redi, M.; Reiersen, W.; Rutherford, P.; Sanchez, R.; Schmidt, J.; White, R.B.

    2001-01-01

    Compact optimized stellarators offer novel solutions for confining high-beta plasmas and developing magnetic confinement fusion. The 3-D plasma shape can be designed to enhance the MHD stability without feedback or nearby conducting structures and provide drift-orbit confinement similar to tokamaks. These configurations offer the possibility of combining the steady-state low-recirculating power, external control, and disruption resilience of previous stellarators with the low-aspect ratio, high beta-limit, and good confinement of advanced tokamaks. Quasi-axisymmetric equilibria have been developed for the proposed National Compact Stellarator Experiment (NCSX) with average aspect ratio 4-4.4 and average elongation of approximately 1.8. Even with bootstrap-current consistent profiles, they are passively stable to the ballooning, kink, vertical, Mercier, and neoclassical-tearing modes for beta > 4%, without the need for external feedback or conducting walls. The bootstrap current generates only 1/4 of the magnetic rotational transform at beta = 4% (the rest is from the coils), thus the equilibrium is much less nonlinear and is more controllable than similar advanced tokamaks. The enhanced stability is a result of ''reversed'' global shear, the spatial distribution of local shear, and the large fraction of externally generated transform. Transport simulations show adequate fast-ion confinement and thermal neoclassical transport similar to equivalent tokamaks. Modular coils have been designed which reproduce the physics properties, provide good flux surfaces, and allow flexible variation of the plasma shape to control the predicted MHD stability and transport properties

  9. General Relativity and Compact Stars

    International Nuclear Information System (INIS)

    Glendenning, Norman K.

    2005-01-01

    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10 14 times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed

  10. The United Nations Global Compact

    DEFF Research Database (Denmark)

    Rasche, Andreas; Waddock, Sandra; McIntosh, Malcolm

    2013-01-01

    This article reviews the interdisciplinary literature on the UN Global Compact. The review identifies three research perspectives, which scholars have used to study the UN Global Compact so far: a historical perspective discussing the Global Compact in the context of UN-business relations...... key empirical as well as conceptual scholarly contributions. The remainder of this article contains focused summaries of the articles selected for this Special Issue. All articles are introduced and evaluated against the background of the three research perspectives....

  11. Spherical strong-shock generation for shock-ignition inertial fusion

    Energy Technology Data Exchange (ETDEWEB)

    Theobald, W.; Seka, W.; Lafon, M.; Anderson, K. S.; Hohenberger, M.; Marshall, F. J.; Michel, D. T.; Solodov, A. A.; Stoeckl, C.; Edgell, D. H.; Yaakobi, B.; Shvydky, A. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Nora, R.; Betti, R. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Department of Mechanical Engineering and Department of Physics, University of Rochester, Rochester, New York 14623 (United States); Casner, A.; Reverdin, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Ribeyre, X.; Vallet, A. [Université de Bordeaux-CNRS-CEA, CELIA (Centre Lasers Intenses et Applications) UMR 5107 F-33400 Talence (France); Peebles, J.; Beg, F. N. [University of California, San Diego, La Jolla, California 92093 (United States); and others

    2015-05-15

    Recent experiments on the Laboratory for Laser Energetics' OMEGA laser have been carried out to produce strong shocks in solid spherical targets with direct laser illumination. The shocks are launched at pressures of several hundred Mbars and reach Gbar upon convergence. The results are relevant to the validation of the shock-ignition scheme and to the development of an OMEGA experimental platform to study material properties at Gbar pressures. The experiments investigate the strength of the ablation pressure and the hot-electron production at incident laser intensities of ∼2 to 6 × 10{sup 15 }W/cm{sup 2} and demonstrate ablation pressures exceeding 300 Mbar, which is crucial to developing a shock-ignition target design for the National Ignition Facility. The timing of the x-ray flash from shock convergence in the center of the solid plastic target is used to infer the ablation and shock pressures. Laser–plasma instabilities produce hot-electrons with a moderate temperature (<100 keV). The instantaneous conversion efficiencies of laser power into hot-electron power reached up to ∼15% in the intensity spike. The large amount of hot electrons is correlated with an earlier x-ray flash and a strong increase in its magnitude. This suggests that hot electrons contribute to the augmentation of the shock strength.

  12. Borehole plugging by compaction process. Final report

    International Nuclear Information System (INIS)

    Fernandez, R.; MacGowan, C.; Nolan, E.; Morey, R.; Palty, A.

    1976-08-01

    The requirements of an overall program to preserve the integrity of a repository formation are documented. The repository is intended to be in stable earth stratum used as a safe and permanent storage area for nuclear waste material. These wastes represent an environmental hazard for a period of up to 200,000 years. An engineering analysis, a reliability and quality-assurance program, and a development program for borehole plugging by compaction process, using natural earthen materials, are presented. Part 1 provides the engineering analysis of downhole compaction methods and related instrumentation along with a recommended development plan from concept through a pilot in-situ experiment. Part 2 provides a reliability and quality-assurance program from laboratory testing of materials through an in-situ experiment

  13. Large compact dimensions and high energy experiments

    Indian Academy of Sciences (India)

    Minkowski, there are d additional spatial dimensions which are curled up into circles, ... In the framework of string theory, this is also related to the string tension .... This marks an ..... of about 1 TeV, with an uncertainty of about 50 GeV either way — which improves only .... [5] J C Long, H W Chan and J C Price, Nucl. Phys.

  14. FRG compact core - one year experience

    International Nuclear Information System (INIS)

    Knop, W.; Schreiner, P.

    2001-01-01

    The GKSS research centre Geesthacht GmbH operates the MTR-type swimming pool reactor FRG-1 (5 MW) for more than 40 years. The FRG-1 has been upgraded and refurbished many times to follow the changing demands of safe operation and today's needs of high neutron flux for scientific research. High neutron fluxes with highest availability is the permanent demand of the science on the operation of a neutron source. (orig.)

  15. Fundamental structure of steady plastic shock waves in metals

    International Nuclear Information System (INIS)

    Molinari, A.; Ravichandran, G.

    2004-01-01

    materials subjected to very high strain rates from shock wave experiments is discussed

  16. Fundamental structure of steady plastic shock waves in metals

    Science.gov (United States)

    Molinari, A.; Ravichandran, G.

    2004-02-01

    materials subjected to very high strain rates from shock wave experiments is discussed.

  17. Shock Response of Lightweight Adobe Masonry

    Science.gov (United States)

    Sauer, C.; Bagusat, F.; Heine, A.; Riedel, W.

    2018-04-01

    The behavior of a low density and low-strength building material under shock loading is investigated. The considered material is lightweight adobe masonry characterized by a density of 1.2 g/cm3 and a quasi-static uniaxial compressive strength of 2.8 MPa. Planar-plate-impact (PPI) tests with velocities in between 295 and 950 m/s are performed in order to obtain Hugoniot data and to derive parameters for an equation of state (EOS) that captures the occurring phenomenology of porous compaction and subsequent unloading. The resulting EOS description is validated by comparing the experimental free surface velocity time curves with those obtained by numerical simulations of the performed PPI tests. The non-linear compression behavior, including the pore compaction mechanism, constitutes a main ingredient for modelling the response of adobe to blast and high-velocity impact loading. We hence present a modeling approach for lightweight adobe which can be applied to such high rate loading scenarios in future studies. In general, this work shows that PPI tests on lightweight and low-strength geological materials can be used to extract Hugoniot data despite significant material inhomogeneity. Furthermore, we demonstrate that a homogenous material model is able to numerically describe such a material under shock compression and release with a reasonable accuracy.

  18. Diffusion of uranium in compacted sodium bentonite

    International Nuclear Information System (INIS)

    Muurinen, A.; Lehikoinen, J.

    1992-09-01

    In the study the diffusion of uranium dissolved from uranium oxide fuel was studied experimentally in compacted sodium bentonite (Wyoming bentonite MX-80). The experiments were carried out by the through-diffusion method. The parameters varied in the study were the density of bentonite, salt content of the solution and redox conditions. Uranium was dissolved under aerobic conditions in order to simulate oxic conditions possibly caused by radiolysis in the repository

  19. Collisionless shock waves

    International Nuclear Information System (INIS)

    Sagdeev, R.Z.; Kennel, C.F.

    1991-01-01

    Collisionless shocks cannot occur naturally on the earth, because nearly all matter here consists of electrically neutral atoms and molecules. In space, however, high temperatures and ultraviolet radiation from hot stars decompose atoms into their constituent nuclei and electrons, producing a soup of electrically charged particles known as a plasma. Plasma physicists proposed that the collective electrical and magnetic properties of plasmas could produce interactions that take the place of collisions and permit shocks to form. In 1964 the theoretical work found its first experimental confirmation. Norman F. Ness and his colleagues at the Goddard Space Flight Center, using data collected from the iMP-1 spacecraft, detected clear signs that a collisionless shock exists where the solar wind encounters the earth's magnetic field. More recent research has demonstrated that collisionless shocks appear in a dazzling array of astronomical settings. For example, shocks have been found in the solar wind upstream (sunward) of all the planet and comets that have been visited by spacecraft. Violent flares on the sun generate shocks that propagate to the far reaches of the solar system; tremendous galactic outbursts create disruptions in the intergalactic medium that are trillions of times larger. In addition, many astrophysicists think that shocks from supernova explosions in our galaxy accelerate cosmic rays, a class of extraordinarily energetic elementary particles and atomic nuclei that rain down on the earth from all directions

  20. Compact particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo-Decanini, Juan M.

    2017-08-29

    A compact particle accelerator having an input portion configured to receive power to produce particles for acceleration, where the input portion includes a switch, is provided. In a general embodiment, a vacuum tube receives particles produced from the input portion at a first end, and a plurality of wafer stacks are positioned serially along the vacuum tube. Each of the plurality of wafer stacks include a dielectric and metal-oxide pair, wherein each of the plurality of wafer stacks further accelerate the particles in the vacuum tube. A beam shaper coupled to a second end of the vacuum tube shapes the particles accelerated by the plurality of wafer stacks into a beam and an output portion outputs the beam.

  1. Compact vacuum insulation embodiments

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  2. Compact vacuum insulation

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  3. The Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Schmidt, J.

    1987-01-01

    The author discusses his lab's plan for completing the Compact Ignition Tokamak (CIT) conceptual design during calendar year 1987. Around July 1 they froze the subsystem envelopes on the device to continue with the conceptual design. They did this by formalizing a general requirements document. They have been developing the management plan and submitted a version to the DOE July 10. He describes a group of management activities. They released the vacuum vessel Request For Proposals (RFP) on August 5. An RFP to do a major part of the system engineering on the device is being developed. They intend to assemble the device outside of the test cell, then move it into the the test cell, install it there, and bring to the test cell many of the auxiliary facilities from TFTR, for example, power supplies

  4. Compact cryocooler heat exchangers

    International Nuclear Information System (INIS)

    Luna, J.; Frederking, T.H.K.

    1991-01-01

    Compact heat exchangers are subject to different constraints as a room temperature gas is cooled down by a cold stream returning from a JT valve (or a similar cryoprocess component). In particular, the optimization of exchangers for liquid helium systems has to cover a wide range in temperature and density of the fluid. In the present work we address the following thermodynamic questions: 1. The optimization of intermediate temperatures which optimize stage operation (a stage is assumed to have a constant cross section); 2. The optimum temperature difference available for best overall economic performance values. The results are viewed in the context of porous media concepts applied to rather low speeds of fluid flow in narrow passages. In this paper examples of fluid/solid constraints imposed in this non-classical low temperature area are presented

  5. Compact semiconductor lasers

    CERN Document Server

    Yu, Siyuan; Lourtioz, Jean-Michel

    2014-01-01

    This book brings together in a single volume a unique contribution by the top experts around the world in the field of compact semiconductor lasers to provide a comprehensive description and analysis of the current status as well as future directions in the field of micro- and nano-scale semiconductor lasers. It is organized according to the various forms of micro- or nano-laser cavity configurations with each chapter discussing key technical issues, including semiconductor carrier recombination processes and optical gain dynamics, photonic confinement behavior and output coupling mechanisms, carrier transport considerations relevant to the injection process, and emission mode control. Required reading for those working in and researching the area of semiconductors lasers and micro-electronics.

  6. Anomalous mass transport in Au/304 stainless steel powder under shock loading

    Energy Technology Data Exchange (ETDEWEB)

    Staudhammer, Karl P.

    2004-01-01

    Dynamic deformation experiments on gold plated 304L stainless steel powders were undertaken using a axial symmetrical implosion geometry. These experiments utilized pressures of 0.08 to 1.0 Mbar and contained a symmetric radial melt region along the central axis of the sample holder. To understand the role of deformation in a porous material, the pressure, and temperature as well as the deformation heat and associated defects must be accounted for. Using a strain controllable shock loading design it was possible to separate and control independently strain and pressure. Thus enabling the ability to control the added heat from the deformation process undergoing compaction/consolidation of the powder. When the added heat of consolidation deformation exceeds the melt temperature of the 304 powders, a melt zone results that can consume large regions of the compact. It is within these regions that very high diffusion of gold into the powder occurs. These anomalous increases have been observed via optical microscopy, scanning electron microscopy and EDAX measurements. Values exceeding 1200 m/sec have been measured and correlated to the powder sizes, size distribution and packing density, concomitant with sample container strains ranging from 2.0% to 26%.

  7. Pressurized Thermal Shock, Pts

    International Nuclear Information System (INIS)

    Boyd, C.

    2008-01-01

    Pressurized Thermal Shock (Pts) refers to a condition that challenges the integrity of the reactor pressure vessel. The root cause of this problem is the radiation embrittlement of the reactor vessel. This embrittlement leads to an increase in the reference temperature for nil ductility transition (RTNDT). RTNDT can increase to the point where the reactor vessel material can loose fracture toughness during overcooling events. The analysis of the risk of having a Pts for a specific plant is a multi-disciplinary problem involving probabilistic risk analysis (PRA), thermal-hydraulic analysis, and ultimately a structural and fracture analysis of the vessel wall. The PRA effort involves the postulation of overcooling events and ultimately leads to an integrated risk analysis. The thermal-hydraulic effort involves the difficult task of predicting the system behavior during a postulated overcooling scenario with a special emphasis on predicting the thermal and mechanic loadings on the reactor pressure vessel wall. The structural and fracture analysis of the reactor vessel wall relies on the thermal-hydraulic conditions as boundary conditions. The US experience has indicated that medium and large diameter primary system breaks dominate the risk of Pts along with scenarios that involve a stuck open valve (and associated system cooldown) that recloses resulting in system re-pressurization while the vessel wall is cool.

  8. Pediatric Toxic Shock Syndrome

    Directory of Open Access Journals (Sweden)

    Jennifer Yee

    2017-09-01

    Full Text Available Audience: This scenario was developed to educate emergency medicine residents on the diagnosis and management of a pediatric patient with toxic shock syndrome. The case is also appropriate for teaching of medical students and advanced practice providers, as well as a review of the principles of crisis resource management, teamwork, and communication. Introduction: Toxic shock syndrome is a low-frequency, high-acuity scenario requiring timely identification and aggressive management. If patients suffering from this condition are managed incorrectly, they may progress into multi-organ dysfunction and potentially death. Toxic shock syndrome has been associated with Streptococcus and Staphylococcus aureus (Staph. Approximately half of Staph cases are associated with menstruation, which was first described in the 1970s-1980s and was associated with the use of absorbent tampons.1 Group A Streptococcus may cause complications such as necrotizing fasciitis and gangrenous myositis.2 Pediatric patients may present critically ill from toxic shock syndrome. Providers need to perform a thorough history and physical exam to discern the source of infection. Management requires aggressive care with antibiotics and IV fluids. Objectives: By the end of this simulation session, the learner will be able to: 1 Recognize toxic shock syndrome. 2 Review the importance of a thorough physical exam. 3 Discuss management of toxic shock syndrome, including supportive care and the difference in antibiotic choices for streptococcal and staphylococcal toxic shock syndrome. 4 Appropriately disposition a patient suffering from toxic shock syndrome. 5 Communicate effectively with team members and nursing staff during a resuscitation of a critically ill patient. Method: This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on toxic shock syndrome.

  9. Shocks near Jamming

    Science.gov (United States)

    Gómez, Leopoldo R.; Turner, Ari M.; van Hecke, Martin; Vitelli, Vincenzo

    2012-02-01

    Nonlinear sound is an extreme phenomenon typically observed in solids after violent explosions. But granular media are different. Right when they jam, these fragile and disordered solids exhibit a vanishing rigidity and sound speed, so that even tiny mechanical perturbations form supersonic shocks. Here, we perform simulations in which two-dimensional jammed granular packings are dynamically compressed and demonstrate that the elementary excitations are strongly nonlinear shocks, rather than ordinary phonons. We capture the full dependence of the shock speed on pressure and impact intensity by a surprisingly simple analytical model.

  10. Mechanical shock absorber

    International Nuclear Information System (INIS)

    Vrillon, Bernard.

    1973-01-01

    The mechanical shock absorber described is made of a constant thickness plate pierced with circular holes regularly distributed in such a manner that for all the directions along which the strain is applied during the shock, the same section of the substance forming the plate is achieved. The shock absorber is made in a metal standing up to extensive deformation before breaking, selected from a group comprising mild steels and austenitic stainless steels. This apparatus is used for handling pots of fast neutron reactor fuel elements [fr

  11. Shock formation of HCO+

    International Nuclear Information System (INIS)

    Elitzur, M.

    1983-01-01

    It is shown that shocks propagating in dense molecular regions will lead to a decrease in HCO + relative abundance, in agreement with previous results by Iglesias and Silk. The shock enhancement of HCO + detected in the supernova remnant IC 443 by Dickenson et al. is due to enhanced ionization in the shocked material. This is the result of the material penetrating the remnant cavity where it becomes exposed to the trapped cosmic rays. A similar enhancement appears to have been detected by Wootten in W28 and is explained by the same model

  12. Emissive spectra of shock-heated argon

    International Nuclear Information System (INIS)

    Tang Jingyou; Gu Yan; Peng Qixian; Bai Yulin; Li Ping

    2003-01-01

    To study the radiant properties of argon under weak shock compression, an aluminum target filled with gaseous argon at ambient states was impacted by a tungsten alloy projectile which was launched from a two-stage light gun to 2.00 km/s. The radiant signals of single shock-compressed argon were recorded by a six-channel pyrometer and oscilloscopes, which varied with time linearly for the five channels from 405 nm to 700 nm and exponentially for the channel 800 nm, and the corresponding velocity of shock wave was determined to be 4.10 ± 0.09 km/s. By the present experiment, it has been shown that the absorbability of the shock-heated argon is low for visual light and the optical depths of argon gas turn from thin to thick as wavelengths gradually increase. The time-resolved spectra in the rising-front of the radiant signal in the re-shocked argon were recorded by means of an OMA, and strong emissive spectrum bands near 450 nm light-wave length but no linear spectrum were found. The emissive spectrum properties of shock-compression argon were qualitatively explained by the state parameters and ionization degree

  13. Attenuation of shock waves in copper and stainless steel

    International Nuclear Information System (INIS)

    Harvey, W.B.

    1986-06-01

    By using shock pins, data were gathered on the trajectories of shock waves in stainless steel (SS-304L) and oxygen-free-high-conductivity copper (OFHC-Cu). Shock pressures were generated in these materials by impacting the appropriate target with thin (approx.1.5 mm) flying plates. The flying plates in these experiments were accelerated to high velocities (approx.4 km/s) by high explosives. Six experiments were conducted, three using SS-304L as the target material and three experiments using OFHC-Cu as the target material. Peak shock pressures generated in the steel experiments were approximately 109, 130, and 147 GPa and in the copper experiments, the peak shock pressures were approximately 111, 132, and 143 GPa. In each experiment, an attenuation of the shock wave by a following release wave was clearly observed. An extensive effort using two characteristic codes (described in this work) to theoretically calculate the attenuation of the shock waves was made. The efficacy of several different constitutive equations to successfully model the experiments was studied by comparing the calculated shock trajectories to the experimental data. Based on such comparisons, the conclusion can be drawn that OFHC-Cu enters a melt phase at about 130 GPa on the principal Hugoniot. There was no sign of phase changes in the stainless-steel experiments. In order to match the observed attenuation of the shock waves in the SS-304L experiments, it was necessary to include strength effects in the calculations. It was found that the values for the parameters in the strength equations were dependent on the equation of state used in the modeling of the experiments. 66 refs., 194 figs., 77 tabs

  14. Attenuation of shock waves in copper and stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, W.B.

    1986-06-01

    By using shock pins, data were gathered on the trajectories of shock waves in stainless steel (SS-304L) and oxygen-free-high-conductivity copper (OFHC-Cu). Shock pressures were generated in these materials by impacting the appropriate target with thin (approx.1.5 mm) flying plates. The flying plates in these experiments were accelerated to high velocities (approx.4 km/s) by high explosives. Six experiments were conducted, three using SS-304L as the target material and three experiments using OFHC-Cu as the target material. Peak shock pressures generated in the steel experiments were approximately 109, 130, and 147 GPa and in the copper experiments, the peak shock pressures were approximately 111, 132, and 143 GPa. In each experiment, an attenuation of the shock wave by a following release wave was clearly observed. An extensive effort using two characteristic codes (described in this work) to theoretically calculate the attenuation of the shock waves was made. The efficacy of several different constitutive equations to successfully model the experiments was studied by comparing the calculated shock trajectories to the experimental data. Based on such comparisons, the conclusion can be drawn that OFHC-Cu enters a melt phase at about 130 GPa on the principal Hugoniot. There was no sign of phase changes in the stainless-steel experiments. In order to match the observed attenuation of the shock waves in the SS-304L experiments, it was necessary to include strength effects in the calculations. It was found that the values for the parameters in the strength equations were dependent on the equation of state used in the modeling of the experiments. 66 refs., 194 figs., 77 tabs.

  15. Experimental Shock Transformation of Gypsum to Anhydrite: A New Low Pressure Regime Shock Indicator

    Science.gov (United States)

    Bell, Mary S.; Zolensky, Michael E.

    2011-01-01

    The shock behavior of gypsum is important in understanding the Cretaceous/Paleogene event and other terrestrial impacts that contain evaporite sediments in their targets (e.g., Mars Exploration Rover Spirit detected sulfate at Gusev crater, [1]). Most interest focuses on issues of devolatilization to quantify the production of SO2 to better understand its role in generating a temporary atmosphere and its effects on climate and biota [2,3]. Kondo and Ahrens [4] measured induced radiation emitted from single crystal gypsum shocked to 30 and 40 GPa. They observed greybody emission spectra corresponding to temperatures in the range of 3,000 to 4,000 K that are a factor of 2 to 10 times greater than calculated pressure-density energy equation of state temperatures (Hugoniot) and are high enough to melt gypsum. Chen et al. [5] reported results of shock experiments on anhydrite, gypsum, and mixtures of these phases with silica. Their observations indicated little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another report of shock experiments on calcite, anhydrite, and gypsum, Badjukov et al. [6] observed only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa but have not experimentally shocked gypsum in a step-wise manner to constrain possible incipient transformation effects. Schmitt and Hornemann [7] shock loaded anhydrite and quartz to a peak pressure of 60 GPa and report the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggested that recrystallization of anhydrite grains is the result of a solid-state transformation. They concluded that significant decomposition of anhydrite requires shock pressures higher than 60 GPa. Gupta et al. [8

  16. Shock Isolation Elements Testing for High Input Loadings. Volume II. Foam Shock Isolation Elements.

    Science.gov (United States)

    SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*EXPANDED PLASTICS, (*SHOCK(MECHANICS), REDUCTION), TEST METHODS, SHOCK WAVES, STRAIN(MECHANICS), LOADS(FORCES), MATHEMATICAL MODELS, NUCLEAR EXPLOSIONS, HARDENING.

  17. Thermophysical properties of multi-shock compressed dense argon.

    Science.gov (United States)

    Chen, Q F; Zheng, J; Gu, Y J; Chen, Y L; Cai, L C; Shen, Z J

    2014-02-21

    In contrast to the single shock compression state that can be obtained directly via experimental measurements, the multi-shock compression states, however, have to be calculated with the aid of theoretical models. In order to determine experimentally the multiple shock states, a diagnostic approach with the Doppler pins system (DPS) and the pyrometer was used to probe multiple shocks in dense argon plasmas. Plasma was generated by a shock reverberation technique. The shock was produced using the flyer plate impact accelerated up to ∼6.1 km/s by a two-stage light gas gun and introduced into the plenum argon gas sample, which was pre-compressed from the environmental pressure to about 20 MPa. The time-resolved optical radiation histories were determined using a multi-wavelength channel optical transience radiance pyrometer. Simultaneously, the particle velocity profiles of the LiF window was measured with multi-DPS. The states of multi-shock compression argon plasma were determined from the measured shock velocities combining the particle velocity profiles. We performed the experiments on dense argon plasmas to determine the principal Hugonoit up to 21 GPa, the re-shock pressure up to 73 GPa, and the maximum measure pressure of the fourth shock up to 158 GPa. The results are used to validate the existing self-consistent variational theory model in the partial ionization region and create new theoretical models.

  18. Compact magnetic fusin reactor concepts

    International Nuclear Information System (INIS)

    Chung, K.M.

    1984-01-01

    Compact, high-power-density approaches to fusion power represent alternatives to main-line fusion concepts, Tokamaks and mirrors. If technological issues are resolved, theses approaches would yield small, low-cost fusion power plants. This survey reviews the principal physics and technology employed by leading compact magnetic fusion plants. (Author)

  19. Solid targetry for compact cyclotrons

    International Nuclear Information System (INIS)

    Comor, J.

    2004-01-01

    In this presentation authors present experimental results of solid targetry for compact cyclotrons. It is concluded: Solid targetry is not restricted to large accelerator centers anymore; Small and medium scale radioisotope production is feasible with compact cyclotrons; The availability of versatile solid target systems is expected to boost the radiochemistry of 'exotic' positron emitters

  20. Roller-compacted concrete pavements.

    Science.gov (United States)

    2010-09-01

    Roller-compacted concrete (RCC) gets its name from the heavy vibratory steel drum and rubber-tired rollers used to help compact it into its final form. RCC has similar strength properties and consists of the same basic ingredients as conventional con...

  1. Machine for compacting solid residues

    International Nuclear Information System (INIS)

    Herzog, J.

    1981-11-01

    Machine for compacting solid residues, particularly bulky radioactive residues, constituted of a horizontally actuated punch and a fixed compression anvil, in which the residues are first compacted horizontally and then vertically. Its salient characteristic is that the punch and the compression anvil have embossments on the compression side and interpenetrating plates in the compression position [fr

  2. Defining Moments in MMWR History: Toxic-Shock Syndrome -- 1980

    Centers for Disease Control (CDC) Podcasts

    In the late 1970s and early 1980s, an outbreak of a disease called Toxic Shock Syndrome made healthy women sick. CDC's disease detectives helped unravel the link between Toxic Shock Syndrome and high-absorbency tampons. MMWR was the first scientific publication to break the news of these cases. In this podcast, Dr. Kathy Shands, former chief of CDC's Toxic Shock Syndrome Task Force, recalls her experience working with state epidemiologists to identify the link between toxic shock syndrome and tampon use.

  3. Defining Moments in MMWR History: Toxic-Shock Syndrome -- 1980

    Centers for Disease Control (CDC) Podcasts

    2017-11-03

    In the late 1970s and early 1980s, an outbreak of a disease called Toxic Shock Syndrome made healthy women sick. CDC’s disease detectives helped unravel the link between Toxic Shock Syndrome and high-absorbency tampons. MMWR was the first scientific publication to break the news of these cases. In this podcast, Dr. Kathy Shands, former chief of CDC’s Toxic Shock Syndrome Task Force, recalls her experience working with state epidemiologists to identify the link between toxic shock syndrome and tampon use.  Created: 11/3/2017 by MMWR.   Date Released: 11/3/2017.

  4. Factors Affecting the Outcome of Extracorporeal Shock Wave Lithotripsy for Unilateral Urinary Stones in Children: A 17-Year Single-Institute Experience

    Science.gov (United States)

    Jeong, U-Seok; Lee, Sinwoo; Kang, Junghun; Han, Deok Hyun; Park, Kwan Hyun

    2013-01-01

    Purpose Extracorporeal shock wave lithotripsy (ESWL) is a first-line treatment for pediatric urinary stone disease. We aimed to determine the factors affecting the outcome of ESWL for unilateral urinary stones in children. Materials and Methods A total of 81 pediatric patients aged 0 to 16 years with urinary stones treated by ESWL from January 1995 through May 2012 were retrospectively reviewed. All patients were required to have unilateral urinary stone disease. Children who underwent other surgical procedures before ESWL were excluded. Outcomes evaluated after ESWL were the stone-free rate at 3 months after ESWL, success within a single session, and success within three sessions. Factors affecting the success within three sessions were also analyzed. Results The final analysis was for 42 boys and 22 girls (mean age, 9.2±5.2 years). Of these 64 patients, 58 (90.6%) were treated by ESWL without other surgical procedures and 54 (84.4%) were successfully treated within three ESWL sessions. In the multivariate analysis, multiplicity (odds ratio [OR], 0.080; 95% confidence interval [CI], 0.012 to 0.534; p=0.009) and large stone size (>10 mm; OR, 0.112; 95% CI, 0.018 to 0.707; p=0.020) were significant factors that decreased the success rate within three ESWL sessions. Conclusions Most of the pediatric urinary stone patients in our study (90.6%) were successfully treated by ESWL alone without additional procedures. If a child has a large urinary stone (>10 mm) or multiplicity, clinicians should consider that several ESWL sessions might be needed for successful stone fragmentation. PMID:23878689

  5. Comparison of ureteroscopic pneumatic lithotripsy and extracorporeal shock wave lithotripsy for the management of proximal ureteral stones: A single center experience.

    Science.gov (United States)

    Iqbal, Nadeem; Malik, Yashfeen; Nadeem, Utbah; Khalid, Maham; Pirzada, Amna; Majeed, Mehr; Malik, Hajra Arshad; Akhter, Saeed

    2018-05-01

    To evaluate and compare the effectiveness of ureteroscopic (URS) pneumatic lithotripsy versus extracorporeal shock wave lithotripsy (ESWL) in the management of the proximal ureteral stones in terms of stone- free rates, complications and costs involved. We included 200 patients in Group 1 who underwent ESWL and 200 patients in Group 2 who underwent URS intervention. We used Modulith SL X lithotripter 3 rd generation Storz medical for ESWL group while Swiss pneumatic lithoclast was used to break the stone in the URS group. Stone-free status was defined as stone fragment of less than 4 mm on follow- up kidney ureter and bladder X-ray after 3 months of procedure. SPSS version 16 was used for statistical analysis. The mean age in ESWL and URS groups were 39.21±13.36, and 43.13±13.65 years respectively. Mean stone size was 10.47±3.7 mm (ESWL) and 13.6±6.6 mm (URS). Stone- free rate after single procedure was (125/200 patients) 62.5% for ESWL and (168/200 patients) 84% for URS group (p=0.001). Complications included post procedure sepsis in 3 (1.5%) patient of ESWL, while 7 (3.5%) patients of URS groups. Steinstrasse was seen in 4 (2%) patients of ESWL group. No mortality was seen in both groups. Mean costs for ESWL were US $320±50 while US $1100±150 for URS group (p=0.001). The stone-free rates after single procedure were significantly higher for the URS group while the complication rates were comparable in both groups. Treatment costs were significantly lower for the ESWL group.

  6. Shock-induced borehole waves and fracture effects

    NARCIS (Netherlands)

    Fan, H.; Smeulders, D.M.J.

    2012-01-01

    We perform wave experiments using a vertical shock tube setup. Shock waves are generated by the rupture of a thin membrane. In the test section the incident pressure waves generate borehole-guided waves along water-saturated samples. The tube is equipped with side wall gages and a mobile pressure

  7. Shock timing measurements in DT ice layers

    Science.gov (United States)

    Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R. J.; Ross, J. S.; Lepape, S.; Ralph, J. E.; Berzak Hopkins, L. F.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Boehly, T. R.; Nikroo, A.; Landen, O. L.; Edwards, M. J.

    2013-10-01

    Shock timing experiments on the National Ignition Facility (NIF) are routinely conducted using the keyhole target geometry, in which the strength and timing of multiple shocks are measured in a liquid-deuterium (D2) filled capsule interior. These targets have recently been modified to improve the surrogacy to ignition implosions by replacing the standard, continuous liquid D2 capsule fill with a deuterium-tritium (DT) ice layer with a central DT gas fill. These experiments remove any possible material surrogacy difference between D2 and DT as well as incorporating the physics of multiple shock release and recompression events from an ice layer of finite thickness, an effect that is absent in the liquid-filled targets. Experimental results and comparisons with numerical simulation are presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

  8. Shock Tube as an Impulsive Application Device

    Directory of Open Access Journals (Sweden)

    Soumya Ranjan Nanda

    2017-01-01

    Full Text Available Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

  9. Shock wave focusing in water inside convergent structures

    Directory of Open Access Journals (Sweden)

    C Wang

    2016-09-01

    Full Text Available Experiments on shock focusing in water-filled convergent structures have been performed. A shock wave in water is generated by means of a projectile, launched from a gas gun, which impacts a water-filled convergent structure. Two types of structures have been tested; a bulk material and a thin shell structure. The geometric shape of the convergent structures is given by a logarithmic spiral, and this particular shape is chosen because it maximizes the amount of energy reaching the focal region. High-speed schlieren photography is used to visualize the shock dynamics during the focusing event. Results show that the fluid-structure interaction between the thin shell structure and the shock wave in the water is different from that of a bulk structure; multiple reflections of the shock wave inside the thin shell are reflected back into the water, thus creating a wave train, which is not observed for shock focusing in a bulk material.

  10. Thermal shock considerations for the TFCX limiter and first wall

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Resistance to thermal shock fracture of limiter and first wall surface material candidates during plasma disruption heating conditions is evaluated. A simple, figure-of-merit type thermal shock parameter which provides a mechanism to rank material candidates is derived. Combining this figure-of-merit parameter with the parameters defining specific heating conditions yields a non-dimensional thermal shock parameter. For values of this parameter below a critical value, a given material is expected to undergo thermal shock damage. Prediction of thermal shock damage with this parameter is shown to exhibit good agreement with test data. Applying this critical parameter value approach, all materials examined in this study are expected to experience thermal shock damage for nominal TFCX plasma disruption conditions. Since the extent of this damage is not clear, tests which explore the range of expected conditions for TFCX are recommended

  11. Numerical simulation of the structure of collisionless supercritical shocks

    International Nuclear Information System (INIS)

    Lipatov, A.S.

    1990-01-01

    Research on the structure of a collisionless shock wave and on acceleration of charged particles is important for analyzing the processes accompanying solar flares, and also for studying the shock waves which are excited in the interaction of the solar wind with planets, comets and interstellar gas, the mechanisms for the acceleration of cosmic rays, the processes accompanying magnetic field reconnection, explosion of Supernova. The study of the shock is also important for studying the processes in the active experiments in space. In the present report only supercritical shocks are considered, when partial ion reflection plays a controlling roll in shock formation. One- and two-dimensional simulations of the perpendicular shocks are presented. (R.P.) 33 refs.; 4 figs

  12. Counseling For Future Shock

    Science.gov (United States)

    Morgan, Lewis B.

    1974-01-01

    In this article the author looks at some of the searing prophecies made by Alvin Toffler in his book Future Shock and relates them to the world of the professional counselor and the clientele the counselor attempts to serve. (Author)

  13. Life shocks and homelessness.

    Science.gov (United States)

    Curtis, Marah A; Corman, Hope; Noonan, Kelly; Reichman, Nancy E

    2013-12-01

    We exploited an exogenous health shock-namely, the birth of a child with a severe health condition-to investigate the effect of a life shock on homelessness in large cities in the United States as well as the interactive effects of the shock with housing market characteristics. We considered a traditional measure of homelessness, two measures of housing instability thought to be precursors to homelessness, and a combined measure that approximates the broadened conceptualization of homelessness under the 2009 Homeless Emergency Assistance and Rapid Transition to Housing Act (2010). We found that the shock substantially increases the likelihood of family homelessness, particularly in cities with high housing costs. The findings are consistent with the economic theory of homelessness, which posits that homelessness results from a conjunction of adverse circumstances in which housing markets and individual characteristics collide.

  14. Unlimited Relativistic Shock Surfing Acceleration

    International Nuclear Information System (INIS)

    Ucer, D.; Shapiro, V. D.

    2001-01-01

    Nonrelativistic shock surfing acceleration at quasiperpendicular shocks is usually considered to be a preacceleration mechanism for slow pickup ions to initiate diffusive shock acceleration. In shock surfing, the particle accelerates along the shock front under the action of the convective electric field of the plasma flow. However, the particle also gains kinetic energy normal to the shock and eventually escapes downstream. We consider the case when ions are accelerated to relativistic velocities. In this case, the ions are likely to be trapped for infinitely long times, because the energy of bounce oscillations tends to decrease during acceleration. This suggests the possibility of unlimited acceleration by shock surfing

  15. Technology shocks matter

    OpenAIRE

    Jonas D. M. Fisher

    2002-01-01

    This paper uses the neoclassical growth model to identify the effects of technological change on the US business cycle. In the model there are two sources of technological change: neutral, which effects the production of all goods homogeneously, and investment-specific. Investment-specific shocks are the unique source of the secular trend in the real price of investment goods, while shocks to both kinds of technology are the only factors which affect labor productivity in the long run. Consis...

  16. Compaction of an Oxisol and chemical composition of palisadegrass

    Directory of Open Access Journals (Sweden)

    Eurico Lucas de Sousa Neto

    2013-08-01

    Full Text Available Compaction is an important problem in soils under pastoral land use, and can make livestock systems unsustainable. The objective of this research was to study the impact of soil compaction on yield and quality of palisade (UROCHLOA BRIZANTHA cv. Marandu. The experiment was conducted on an Oxisol in the State of Mato Grosso, Brazil. Treatments consisted of four levels of soil compaction: no compaction (NC, slight compaction (SC, medium compaction (MC and high compaction (HC. The following soil properties were evaluated (layers 0-0.05 and 0.05-0.10 m: aggregate size distribution, bulk density (BD, macroporosity, microporosity, total porosity (TP, relative compaction (RC, and the characteristics of crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF and dry matter yield (DMY of the forage. Highly compacted soil had high BD and RC, and low TP (0-0.05 m. Both DMY and CP were affected by HC, and both were strongly related to BD. Higher DMY (6.96 Mg ha-1 and CP (7.8 % were observed in the MC treatment (BD 1.57 Mg m-3 and RC 0.91 Mg m-3, in 0-0.05 m. A high BD of 1.57 Mg m-3 (0-0.05 m did not inhibit plant growth. The N concentration in the palisade biomass differed significantly among compaction treatments, and was 8.72, 11.20, 12.48 and 10.98 g kg-1 in NC, SC, MC and HC treatments, respectively. Increase in DMY and CP at the MC level may be attributed to more absorption of N in this coarse-textured soil.

  17. The Heliospheric Termination Shock

    Science.gov (United States)

    Jokipii, J. R.

    2013-06-01

    The heliospheric termination shock is a vast, spheroidal shock wave marking the transition from the supersonic solar wind to the slower flow in the heliosheath, in response to the pressure of the interstellar medium. It is one of the most-important boundaries in the outer heliosphere. It affects energetic particles strongly and for this reason is a significant factor in the effects of the Sun on Galactic cosmic rays. This paper summarizes the general properties and overall large-scale structure and motions of the termination shock. Observations over the past several years, both in situ and remote, have dramatically revised our understanding of the shock. The consensus now is that the shock is quite blunt, is with the front, blunt side canted at an angle to the flow direction of the local interstellar plasma relative to the Sun, and is dynamical and turbulent. Much of this new understanding has come from remote observations of energetic charged particles interacting with the shock, radio waves and radiation backscattered from interstellar neutral atoms. The observations and the implications are discussed.

  18. Shock interactions with heterogeneous energetic materials

    Science.gov (United States)

    Yarrington, Cole D.; Wixom, Ryan R.; Damm, David L.

    2018-03-01

    The complex physical phenomenon of shock wave interaction with material heterogeneities has significant importance and nevertheless remains little understood. In many materials, the observed macroscale response to shock loading is governed by characteristics of the microstructure. Yet, the majority of computational studies aimed at predicting phenomena affected by these processes, such as the initiation and propagation of detonation waves in explosives or shock propagation in geological materials, employ continuum material and reactive burn model treatment. In an effort to highlight the grain-scale processes that underlie the observable effects in an energetic system, a grain-scale model for hexanitrostilbene (HNS) has been developed. The measured microstructures were used to produce synthetic computational representations of the pore structure, and a density functional theory molecular dynamics derived equation of state (EOS) was used for the fully dense HNS matrix. The explicit inclusion of the microstructure along with a fully dense EOS resulted in close agreement with historical shock compression experiments. More recent experiments on the dynamic reaction threshold were also reproduced by inclusion of a global kinetics model. The complete model was shown to reproduce accurately the expected response of this heterogeneous material to shock loading. Mesoscale simulations were shown to provide a clear insight into the nature of threshold behavior and are a way to understand complex physical phenomena.

  19. A compact fiber optics-based heterodyne combined normal and transverse displacement interferometer.

    Science.gov (United States)

    Zuanetti, Bryan; Wang, Tianxue; Prakash, Vikas

    2017-03-01

    While Photonic Doppler Velocimetry (PDV) has become a common diagnostic tool for the measurement of normal component of particle motion in shock wave experiments, this technique has not yet been modified for the measurement of combined normal and transverse motion, as needed in oblique plate impact experiments. In this paper, we discuss the design and implementation of a compact fiber-optics-based heterodyne combined normal and transverse displacement interferometer. Like the standard PDV, this diagnostic tool is assembled using commercially available telecommunications hardware and uses a 1550 nm wavelength 2 W fiber-coupled laser, an optical focuser, and single mode fibers to transport light to and from the target. Two additional optical probes capture first-order beams diffracted from a reflective grating at the target free-surface and deliver the beams past circulators and a coupler where the signal is combined to form a beat frequency. The combined signal is then digitized and analyzed to determine the transverse component of the particle motion. The maximum normal velocity that can be measured by this system is limited by the equivalent transmission bandwidth (3.795 GHz) of the combined detector, amplifier, and digitizer and is estimated to be ∼2.9 km/s. Sample symmetric oblique plate-impact experiments are performed to demonstrate the capability of this diagnostic tool in the measurement of the combined normal and transverse displacement particle motion.

  20. TYPE IIb SUPERNOVAE WITH COMPACT AND EXTENDED PROGENITORS

    International Nuclear Information System (INIS)

    Chevalier, Roger A.; Soderberg, Alicia M.

    2010-01-01

    The classic example of a Type IIb supernova is SN 1993J, which had a cool extended progenitor surrounded by a dense wind. There is evidence for another category of Type IIb supernova that has a more compact progenitor with a lower density, probably fast, wind. Distinguishing features of the compact category are weak optical emission from the shock heated envelope at early times, nonexistent or very weak H emission in the late nebular phase, rapidly evolving radio emission, rapid expansion of the radio shell, and expected nonthermal as opposed to thermal X-ray emission. Type IIb supernovae that have one or more of these features include SNe 1996cb, 2001ig, 2003bg, 2008ax, and 2008bo. All of these with sufficient radio data (the last four) show evidence for presupernova wind variability. We estimate a progenitor envelope radius ∼1 x 10 11 cm for SN 2008ax, a value consistent with a compact Wolf-Rayet progenitor. Supernovae in the SN 1993J extended category include SN 2001gd and probably the Cas A supernova. We suggest that the compact Type IIb events be designated Type cIIb and the extended ones Type eIIb. The H envelope mass dividing these categories is ∼0.1 M sun .