WorldWideScience

Sample records for cannon laser shot

  1. Research on droplet size measurement of impulse antiriots water cannon based on sheet laser

    Science.gov (United States)

    Fa-dong, Zhao; Hong-wei, Zhuang; Ren-jun, Zhan

    2014-04-01

    As a new-style counter-personnel non-lethal weapon, it is the non-steady characteristic and large water mist field that increase the difficulty of measuring the droplet size distribution of impulse anti-riots water cannon which is the most important index to examine its tactical and technology performance. A method based on the technologies of particle scattering, sheet laser imaging and high speed handling was proposed and an universal droplet size measuring algorithm was designed and verified. According to this method, the droplet size distribution was measured. The measuring results of the size distribution under the same position with different timescale, the same axial distance with different radial distance, the same radial distance with different axial distance were analyzed qualitatively and some rational cause was presented. The droplet size measuring method proposed in this article provides a scientific and effective experiment method to ascertain the technical and tactical performance and optimize the relative system performance.

  2. Development of Laser Rifle Trainer with Full Shot Imitation

    OpenAIRE

    Bansevicius, Ramutis; Fedaravicius, Algimantas; Ostasevicius, Vytautas; Ragulskis, Minvydas

    2004-01-01

    Laser trainers are effective tools for shot and sportsmen training. However, the majority of trainers have neither realistic recoil nor sound imitation systems. The objective of the development of laser rifle trainer with full shot imitation was to investigate and simulate the recoil of combat weapons under single and serial shooting regimes so that the training weapons could simulate complete recoil and sound imitation.Theoretical and experimental investigations lead to the development of sh...

  3. Development of Laser Rifle Trainer with Full Shot Imitation

    Directory of Open Access Journals (Sweden)

    Ramutis Bansevicius

    2004-01-01

    Full Text Available Laser trainers are effective tools for shot and sportsmen training. However, the majority of trainers have neither realistic recoil nor sound imitation systems. The objective of the development of laser rifle trainer with full shot imitation was to investigate and simulate the recoil of combat weapons under single and serial shooting regimes so that the training weapons could simulate complete recoil and sound imitation.

  4. The Cannon

    Science.gov (United States)

    Ness, Melissa; Hogg, David W.; Rix, Hans-Walter; Zasowski, Gail; Ho, Anna

    2015-01-01

    We present a method to estimate stellar parameters and abundances (or "labels") for APOGEE spectra that does not require direct comparison to synthetic model spectra. Our method, called The Cannon, transfers labels (e.g. Teff, logg, [Fe/H]) from a training set of data whose parameters are well determined (i.e. members of open and globular clusters) to the entire set of stars in the survey. We show we can reproduce the stellar parameters for the APOGEE survey for DR10 and achieve this at a fraction (25%) of the signal to noise required by minimisation techniques. We obtain this performance via characterising the relationship between the labels of the stars in our training set and their flux, at each pixel. Our method is expandable to additional labels and relevant for chemical tagging. This approach argues for an established set of standard stars with well-determined labels. Given such standard calibrators, it is possible, via this technique of label transfer, to place every stellar survey of the Milky Way on the same stellar parameter scale and homogeneously map the stellar population of the Milky Way from Northern and Southern hemispheres and using different wavelength regions.

  5. Effects of Laser Peening, and Shot Peening, on Friction Stir Welding

    Science.gov (United States)

    Hatamleh, Omar; Hackel, Lloyd; Rankin, Jon; Truong, Chanh; Walter, Matt

    2006-01-01

    A viewgraph presentation describing the effects of laser peening and shot peening on friction stir welding is shown. The topics include: 1) Background; 2) Friction Stir Welding (FSW); 3) Microstructure; 4) Laser & Shot Peening; 5) Residual Stresses; 6) Tensile Behavior; 7) Fatigue Life & Surface Roughness; 8) Crack Growth; and 9) Benefits.

  6. Multiphoton double ionization of Ar in intense extreme ultraviolet laser fields studied by shot-by-shot photoelectron spectroscopy.

    Science.gov (United States)

    Hikosaka, Y; Fushitani, M; Matsuda, A; Tseng, C-M; Hishikawa, A; Shigemasa, E; Nagasono, M; Tono, K; Togashi, T; Ohashi, H; Kimura, H; Senba, Y; Yabashi, M; Ishikawa, T

    2010-09-24

    Photoelectron spectroscopy has been performed to study the multiphoton double ionization of Ar in an intense extreme ultraviolet laser field (hν ∼ 21  eV, ∼ 5  TW/cm²), by using a free electron laser (FEL). Three distinct peaks identified in the observed photoelectron spectra clearly show that the double ionization proceeds sequentially via the formation of Ar(+): Ar+hν→Ar (+) + e⁻ and Ar²(+) + 2hν→Ar(+) + e⁻. Shot-by-shot recording of the photoelectron spectra allows simultaneous monitoring of FEL spectrum and the multiphoton process for each FEL pulse, revealing that the two-photon ionization from Ar(+) is significantly enhanced by intermediate resonances in Ar(+).

  7. Laser Shot Peening Final Report CRADA No. TC-02059-03

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, B. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hackel, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-27

    This was a collaborative effort between The Regents of the University of California, Lawrence Livermore National Laboratory (LLNL) and Metal Improvement Company, Inc. (MIC), to further develop the laser shot peening technology. This project had an emphasis on laser development and government and military applications including DOE’s natural gas and oil technology program (NGOTP), Yucca Mountain Project (YMP), F-22 Fighter, etc.

  8. The Acoustically Driven Vortex Cannon

    Science.gov (United States)

    Perry, Spencer B.; Gee, Kent L.

    2014-01-01

    Vortex cannons have been used by physics teachers for years, mostly to teach the continuity principle. In its simplest form, a vortex cannon is an empty coffee can with a hole cut in the bottom and the lid replaced. More elaborate models can be purchased through various scientific suppliers under names such as "Air Cannon" and…

  9. Study of anti-laser irradiation performance of shot-peened 40CrNiMoA alloy steel

    International Nuclear Information System (INIS)

    Liu, Zhanwei; Wu, Ningning; Huang, Xianfu; Xie, Huimin; Lv, Xintao; He, Guang

    2012-01-01

    In this paper, shot-peening treatment was introduced to reinforce an alloy surface to protect it from laser irradiation, and experiments were carried out on 40CrNiMoA alloy steel. Macro-mechanical properties were studied and compared before and after both shot-peening and laser irradiation by conducting tensile and hardness measurements. Experimental results showed that the shot-peened alloy showed better mechanical properties after laser irradiation when compared to the alloy without shot-peening treatment. The enhanced ability of the shot-peened alloy for anti-laser irradiation was explained as due to the large residual compressive stress distributions over the shot-peening layer greatly reducing the thermal shock effect introduced by the laser. On the other hand, the growth of microstructures in specific shape absorbed the thermal energy during irradiation, giving a higher probability for the alloy to resist damage.

  10. Multiple shot laser-induced damage in dielectrics with absorbing inclusions

    International Nuclear Information System (INIS)

    Nathan, V.

    1996-01-01

    A formula is derived to predict the temperature distribution in a spherical absorbing inclusion embedded in a dielectric, when it is subjected to rectangular multiple laser shots. It is found that the temperature distribution is a complicated function of the radius of the impurity, laser intensity, number of shots, pulse duration, and time interval between pulses. Numerical calculations of the minimum number of shots (n min ) needed to raise the temperature of the impurity-host boundary to the melting point of the impurity are carried out for the case of ThO 2 in ThF 4 for several incident laser intensities (I), pulsewidths (t p ), and time between pulses (t I ). The results show that for fixed values of t I /t p , I(n min t p ) 1/2 is approximately a constant. (orig.)

  11. XRD investigation of microstructure strengthening mechanism of shot peening on laser hardened 17-4PH

    International Nuclear Information System (INIS)

    Wang Zhou; Luan Weizhi; Huang Junjie; Jiang Chuanhai

    2011-01-01

    Highlights: → We analyzed the microstructure of shot peened component. → We estimated the domain size, the microstrain and dislocation density of specimen via XRD profile method. → The domain size increased and microstrain as well as dislocation density decreased with depth increasing. → The surface domain size decreased to nano-scale after shot peening treatment. → The surface dislocation density increased about one order magnitude after shot peening treatment. - Abstract: The influence of shot peening on microstructure of laser hardened 17-4PH was investigated by using X-ray diffraction profiles. The domain size, microstrain and dislocation in different depths were calculated via Voigt method and dislocation density calculation method according to Williamson's work. Two typical materials in laser hardened 17-4PH (matrix material and laser hardened material) and three families of crystalline planes ({1 1 0}, {2 0 0}, {2 1 1}) were chosen as research objects. Microstructural results from XRD investigation quantified the shot peening influence on microstrain, domain size and dislocation density in microstructure changed layer in these three plane diffraction directions. Results showed that shot peening was an efficient cold working method to alter microstructure in near surface region and microstructure strengthening mechanism of shot peening played an important role on improving the surface mechanical properties. In microstructure changed layer, the domain size increased and microstrain as well as dislocation density decreased with depth increasing, which led to the mechanical properties decrease with depth increasing. With increasing peening intensity from 0.2 mmA + 0.1 mmA to 0.5 mmA + 0.1 mmA, the depth of microstructure changed layer increased but the surface microstructure did not change, no matter in matrix material or laser hardened material. As laser hardened material had a stronger resistance against shot peening influence on microstructure, the

  12. Pulsed laser deposition of lysozyme: the dependence on shot numbers and the angular distribution

    DEFF Research Database (Denmark)

    Constantinescu, C.; Matei, A.; Schou, Jørgen

    2013-01-01

    . This was verified by matrix-assisted laser desorption ionization (MALDI) spectrometry of thin films deposited on silicon substrates. The deposition rate of lysozyme was found to decrease with the number of shots and was correlated with increasing thermal damage of the lysozyme. This was monitored by measurements...

  13. Laser conditioning and multi-shot laser damage accumulation effects of HfO2/SiO2 antireflective coatings

    International Nuclear Information System (INIS)

    Zhao Yuanan; Wang Tao; Zhang Dawei; Shao Jianda; Fan Zhengxiu

    2005-01-01

    Laser conditioning effects of the HfO 2 /SiO 2 antireflective (AR) coatings at 1064 nm and the accumulation effects of multi-shot laser radiation were investigated. The HfO 2 /SiO 2 AR coatings were prepared by E-beam evaporation (EBE). The single-shot and multi-shot laser induced damage threshold was detected following ISO standard 11254-1.2, and the laser conditioning was conducted by three-step raster scanning method. It was found that the single-shot LIDT and multi-shot LIDT was almost the same. The damage mostly >80% occurred in the first shot under multi-shot laser radiation, and after that the damage occurring probability plummeted to <5%. There was no obvious enhancement of the laser damage resistance for both the single-shot and multi-shot laser radiation of the AR coatings after laser conditioning. A Nomarski microscope was employed to map the damage morphology, and it found that the damage behavior is defect-initiated for both unconditioned and conditioned samples

  14. Radiation damage to amorphous carbon thin films irradiated by multiple 46.9 nm laser shots below the single-shot damage threshold

    Czech Academy of Sciences Publication Activity Database

    Juha, Libor; Hájková, Věra; Chalupský, Jaromír; Vorlíček, Vladimír; Ritucci, A.; Reale, A.; Zuppella, P.; Störmer, M.

    2009-01-01

    Roč. 105, č. 9 (2009), 093117/1-093117/3 ISSN 0021-8979 R&D Projects: GA AV ČR KAN300100702; GA MŠk LC510; GA MŠk(CZ) LC528; GA MŠk LA08024; GA AV ČR IAA400100701 Institutional research plan: CEZ:AV0Z10100523 Keywords : single-shot damage threshold * multiple-shot exposure damage * amorphous carbon * radiation erosion * capillary-discharge XUV laser Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.072, year: 2009

  15. Laser Shot Peening System Final Report CRADA No. TC-1369-96

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, B. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Harris, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-27

    This CRADA project was established with a primary goal to develop a laser shot peening system which could operate at production throughput rates and produce the desired depth and intensity of induced shots. The first objective was to understand all parameters required for acceptable peening, including pulse energy, pulse temporal format, pulse spatial format, sample configuration and tamping mechanism. The next objective was to demonstrate the technique on representative samples and then on representative parts. The final objective was to implement the technology into a meaningful industrial peen.

  16. Physical application: Cannon case

    Science.gov (United States)

    Prada, D. A.; Tarazona, J. D.; Gómez, J. M.

    2018-04-01

    The study of physical phenomena by means of guided experimentation and experimental thinking, allow students to infer and understand the reason for the different variations that evidence. Parabolic motion of a projectile powered by a cannon under the spring mechanism, generates discussion regarding the choice of the proper angle, according to a certain distance, a known average initial velocity, and a given height. Give the blank is a great encouragement, however, being able to explain which conditions of the environment influenced the failed launches, generates a space of dialogue and a durable concrete learning.

  17. Shot-noise dominant regime of a nanoparticle in a laser beam

    Science.gov (United States)

    Zhong, Changchun; Robicheaux, Francis

    2017-04-01

    The technique of laser levitation of nanoparticles has become increasingly promising in the study of cooling and controlling mesoscopic quantum systems. Unlike a mechanical system, the levitated nanoparticle is less exposed to thermalization and decoherence due to the absence of direct contact with a thermal environment. In ultrahigh vacuum, the dominant source of decoherence comes from the unavoidable photon recoil from the optical trap which sets an ultimate bound for the control of levitated systems. In this paper, we study the shot noise heating and the parametric feedback cooling of an optically trapped anisotropic nanoparticle in the laser shot noise dominant regime. The rotational trapping frequency and shot noise heating rate have a dependence on the shape of the trapped particle. For an ellipsoidal particle, the ratio of the axis lengths and the overall size controls the shot noise heating rate relative to the rotational frequency. For a near spherical nanoparticle, the effective heating rate for the rotational degrees of freedom is smaller than that for translation suggesting that the librational ground state may be easier to achieve than the vibrational ground state.

  18. Pulsed laser deposition of lysozyme: the dependence on shot numbers and the angular distribution

    Science.gov (United States)

    Constantinescu, C.; Matei, A.; Schou, J.; Canulescu, S.; Dinescu, M.

    2013-12-01

    The ejection of molecules from a pressed solid target of lysozyme induced by laser ablation in the UV-regime at a wavelength of 355 nm was investigated. The ablation studies were carried out in vacuum at a laser fluence of 2 J/cm2 for which a significant fraction of proteins remains intact. This was verified by matrix-assisted laser desorption ionization (MALDI) spectrometry of thin films deposited on silicon substrates. The deposition rate of lysozyme was found to decrease with the number of shots and was correlated with increasing thermal damage of the lysozyme. This was monitored by measurements of the optical reflectivity of dry lysozyme. The angular distribution of the mass deposition can be fitted well by Anisimov's hydrodynamic model. The total deposited yield over the entire hemisphere from direct laser ablation of lysozyme was estimated from this model and found to be three orders of magnitude less than the ablated mass.

  19. Laser Peening and Shot Peening Effects on Fatigue Life and Surface Roughness of Friction Stir Welded 7075-T7351 Aluminum

    Science.gov (United States)

    Hatamleh, Omar; Lyons, Jed; Forman, Royce

    2006-01-01

    The effects of laser peening, shot peening, and a combination of both on the fatigue life of Friction Stir Welds (FSW) was investigated. The fatigue samples consisted of dog bone specimens and the loading was applied in a direction perpendicular to the weld direction. Several laser peening conditions with different intensities, durations, and peening order were tested to obtain the optimum peening parameters. The surface roughness resulting from various peening techniques was assessed and characterized. The results indicate a significant increase in fatigue life using laser peening compared to shot peened versus their native welded specimens.

  20. Shot-noise-limited optical Faraday polarimetry with enhanced laser noise cancelling

    International Nuclear Information System (INIS)

    Li, Jiaming; Luo, Le; Carvell, Jeff; Cheng, Ruihua; Lai, Tianshu; Wang, Zixin

    2014-01-01

    We present a shot-noise-limited measurement of optical Faraday rotations with sub-ten-nanoradian angular sensitivity. This extremely high sensitivity is achieved by using electronic laser noise cancelling and phase sensitive detection. Specially, an electronic laser noise canceller with a common mode rejection ratio of over 100 dB was designed and built for enhanced laser noise cancelling. By measuring the Faraday rotation of ambient air, we demonstrate an angular sensitivity of up to 9.0×10 −9  rad/√(Hz), which is limited only by the shot-noise of the photocurrent of the detector. To date, this is the highest angular sensitivity ever reported for Faraday polarimeters in the absence of cavity enhancement. The measured Verdet constant of ambient air, 1.93(3)×10 −9 rad/(G cm) at 633 nm wavelength, agrees extremely well with the earlier experiments using high finesse optical cavities. Further, we demonstrate the applications of this sensitive technique in materials science by measuring the Faraday effect of an ultrathin iron film

  1. Single-Shot, Volumetrically Illuminated, Three-Dimensional, Tomographic Laser-Induced-Fluorescence Imaging in a Gaseous Free Jet

    Science.gov (United States)

    2016-04-28

    Single- shot , volumetrically illuminated, three- dimensional, tomographic laser-induced- fluorescence imaging in a gaseous free jet Benjamin R. Halls...37081 Göttingen, Germany 4School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA 5trmeyer@purdue.edu 6james.gord...us.af.mil Abstract: Single- shot , tomographic imaging of the three-dimensional concentration field is demonstrated in a turbulent gaseous free jet in co-flow

  2. Optimization And Single-Shot Characterization Of Ultrashort Thz Pulses From A Laser Wakefield Accelerator

    International Nuclear Information System (INIS)

    Plateau, G.R.; Matlis, N.H.; van Tilborg, J.; Geddes, C.G.R.; Toth, Cs.; Schroeder, C.B.; Leemans, W.P.

    2009-01-01

    We present spatiotemporal characterization of μJ-class ultrashort THz pulses generated from a laser wakefield accelerator (LWFA). Accelerated electrons, resulting from the interaction of a high-intensity laser pulse with a plasma, emit high-intensity THz pulses as coherent transition radiation. Such high peak-power THz pulses, suitable for high-field (MV/cm) pump-probe experiments, also provide a non-invasive bunch-length diagnostic and thus feedback for the accelerator. The characterization of the THz pulses includes energy measurement using a Golay cell, 2D sign-resolved electro-optic measurement and single-shot spatiotemporal electric-field distribution retrieval using a new technique, coined temporal electric-field cross-Correlation (TEX). All three techniques corroborate THz pulses of ∼ 5 μJ, with peak fields of 100's of kV/cm and ∼ 0.4 ps rms duration.

  3. Frequency-Domain Tomography for Single-shot, Ultrafast Imaging of Evolving Laser-Plasma Accelerators

    Science.gov (United States)

    Li, Zhengyan; Zgadzaj, Rafal; Wang, Xiaoming; Downer, Michael

    2011-10-01

    Intense laser pulses propagating through plasma create plasma wakefields that often evolve significantly, e.g. by expanding and contracting. However, such dynamics are known in detail only through intensive simulations. Laboratory visualization of evolving plasma wakes in the ``bubble'' regime is important for optimizing and scaling laser-plasma accelerators. Recently snap-shots of quasi-static wakes were recorded using frequency-domain holography (FDH). To visualize the wake's evolution, we have generalized FDH to frequency-domain tomography (FDT), which uses multiple probes propagating at different angles with respect to the pump pulse. Each probe records a phase streak, imprinting a partial record of the evolution of pump-created structures. We then topographically reconstruct the full evolution from all phase streaks. To prove the concept, a prototype experiment visualizing nonlinear index evolution in glass is demonstrated. Four probes propagating at 0, 0.6, 2, 14 degrees to the index ``bubble'' are angularly and temporally multiplexed to a single spectrometer to achieve cost-effective FDT. From these four phase streaks, an FDT algorithm analogous to conventional CT yields a single-shot movie of the pump's self-focusing dynamics.

  4. Nanopillar formation from two-shot femtosecond laser ablation of poly-methyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Baset, F.; Popov, K.; Villafranca, A.; Alshehri, A.M.; Guay, J.-M.; Ramunno, L.; Bhardwaj, V.R., E-mail: ravi.bhardwaj@uottawa.ca

    2015-12-01

    Highlights: • We studied morphological evolution and dynamics of two-pulse laser ablation in PMMA. • Nanopillar and volcanic eruption like structures are formed within the ablation crater. • Reflection of shockwave induced by the second laser pulse creates the structures. • Shockwave reflects from the boundary created by the first pulses. • Reflected shockwave causes density pinching in the middle of the ablation region. - Abstract: We present experimental and numerical studies on the morphological evolution and dynamics of femtosecond laser ablation of bulk poly-methyl methacrylate (PMMA) irradiated with a pair of pulses. We show that a nanopillar-like structure is formed in the middle of the ablation crater for pulse energies below single-shot ablation threshold. The nanopillar is ∼400 nm long, lies adjacent to a nanopore, and protrudes ∼150 nm above the sample surface. As the pulse energy is increased gradually, the nanopillar disappears and the nanopore inside the ablation crater becomes larger. At higher pulse energies, a volcanic eruption like structure appears in the middle of the crater whose size and height increases with energy. 2D molecular dynamics simulations reveal that a nanojet and other features observed at higher pulse energies can be formed when the reflection of a shockwave, induced by the second laser pulse, causes density pinching in the middle of the interaction region that rapidly pushes out molten material towards the surface. The shockwave is reflected from the cold boundaries of a modified region created by the first laser pulse.

  5. Recoil Experiments Using a Compressed Air Cannon

    Science.gov (United States)

    Taylor, Brett

    2006-01-01

    Ping-Pong vacuum cannons, potato guns, and compressed air cannons are popular and dramatic demonstrations for lecture and lab. Students enjoy them for the spectacle, but they can also be used effectively to teach physics. Recently we have used a student-built compressed air cannon as a laboratory activity to investigate impulse, conservation of…

  6. Integration of Heat Treatment with Shot Peening of 17-4 Stainless Steel Fabricated by Direct Metal Laser Sintering

    Science.gov (United States)

    AlMangour, Bandar; Yang, Jenn-Ming

    2017-11-01

    Direct metal laser sintering (DMLS) is a promising powder-based additive manufacturing process for fabrication of near-net-shape parts. However, the typically poor fatigue performance of DMLS parts must be addressed for use in demanding industrial applications. Post-treatment can be applied to enhance the performance of such components. Earlier attempts at inducing grain refinement through severe plastic deformation of part surfaces using shot peening improved the physical and mechanical properties of metals without chemical alteration. However, heat treatment can modify the surface-hardening effects attained by shot peening. Hence, we examined the feasibility of applying shot peening combined with heat treatment to improve the performance of DMLS-fabricated 17-4 stainless steel parts through microstructural evolution studies and hardness measurements. Compared to a specimen treated only by shot peening, the sample exposed to additional heat treatment showed increased hardness due to aging of the dominant phase.

  7. Ready, Aim, Fire Your Cannons!

    Science.gov (United States)

    Enderson, Mary C.

    2015-01-01

    This article presents a science, technology, engineering, and mathematics (STEM) activity, building an air cannon, in a mathematics classroom. It describes an investigation grounded in STEM concepts that elementary and middle school teachers carried out to think about ways of implementing STEM activities into their instruction. This particular…

  8. Experimental capabilities of 0.4 PW, 1 shot/min Scarlet laser facility for high energy density science.

    Science.gov (United States)

    Poole, P L; Willis, C; Daskalova, R L; George, K M; Feister, S; Jiang, S; Snyder, J; Marketon, J; Schumacher, D W; Akli, K U; Van Woerkom, L; Freeman, R R; Chowdhury, E A

    2016-06-10

    We report on the recently completed 400 TW upgrade to the Scarlet laser at The Ohio State University. Scarlet is a Ti:sapphire-based ultrashort pulse system that delivers >10  J in 30 fs pulses to a 2 μm full width at half-maximum focal spot, resulting in intensities exceeding 5×1021  W/cm2. The laser fires at a repetition rate of once per minute and is equipped with a suite of on-demand and on-shot diagnostics detailed here, allowing for rapid collection of experimental statistics. As part of the upgrade, the entire laser system has been redesigned to facilitate consistent, characterized high intensity data collection at high repetition rates. The design and functionality of the laser and target chambers are described along with initial data from commissioning experimental shots.

  9. Method for single-shot measurement of picosecond laser pulse-lengths without electronic time dispersion

    International Nuclear Information System (INIS)

    Kyrala, G.A.

    1987-01-01

    A two-source shear pattern recording is proposed as a method for single-shot measurement of the pulse shape from nearly monochromatic sources whose pulse lengths are shorter than their coherence times. The basis of this method relies on the assertion that if two identical electromagnetic pulses are recombined with a time delay greater than the sum of their pulse widths, the recordable spatial pattern has no fringes in it. At an arbitrary delay, translated into an actual spatial recording position, the recorded modulated intensity will sample the corresponding laser intensity at that delay time, but with a modulation due to the coherence function of the electromagnetic pulse. Two arrangements are proposed for recording the pattern. The principles, the design parameters, and the methodologies of these arrangements are presented. Resolutions of the configurations and their limitations are given as well

  10. Full report of laser doppler velocimetry (Het-V) data, results , and analysis for pRad shot 0632

    Energy Technology Data Exchange (ETDEWEB)

    Tupa, Dale [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tainter, Amy Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-21

    This was a collaborative shot with AWE investigators Paul Willis-Patel, David Bell, Seth Grant, David Tarr, and James Richley. The shot was assembled in Los Alamos, after which David Bell set up the probe holder and finalized the alignment. The probe holder location and configuration was modified from previous years to make room for the laser illuminated visible imaging diagnostic. The LANL pRad PDV team was Dale Tupa, Amy Tainter, and Patrick Medina. This shot had three PDV probes: one aimed at the center, one aimed at a feature, one aimed at the reverse side of the shot. The shot also had 9 points of a spectroscopy diagnostic. The pRad team helped set up and field the spectroscopy, but did not help with any data analysis. (The support documentation for the PDV results includes a timing map for the spectroscopy.) Please direct questions on the velocimetry to Dale Tupa or Amy Tainter. The shot radiographs were classified, but the data from the optical diagnostics are not.

  11. Measurement of the single-shot pulse energy of a free electron laser using a cryogenic radiometer

    Energy Technology Data Exchange (ETDEWEB)

    Masahiro, Kato; Norio, Saito; Yuichiro, Morishita; Takahiro, Tanaka [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba (Japan); Masahiro, Kato; Norio, Saito; Kai, Tiedtke; Pavle N, Juranic; Sorokin, A.A.; Richter, M.; Takahiro, Tanaka; Mitsuru, Nagasono; Makina, Yabashi; Kensuke, Tono; Tadashi, Togashi; Tetsuya, Ishikawa [RIKEN, XFEL Project Head Office, Kouto, Sayo, Hyogo (Japan); Kai, Tiedtke; Pavle N, Juranic; Sorokin, A.A.; Jastrow, U. [Deutsches Elektronen-Synchrotron, DESY, Hamburg (Germany); Sorokin, A.A. [Ioffe Physico-Technical Institute, Polytekhnicheskaya 26, St Petersburg (Russian Federation); Richter, M.; Kroth, U.; Schoppe, H. [Physikalisch-Technische Bundesanstalt, PTB, Berlin (Germany); Tadashi, Togashi; Hiroaki, Kimura; Haruhiko, Ohashi [Japan Synchrotron Radiation Research Institute, Sayo, Hyogo (Japan)

    2010-10-15

    The absolute single-shot pulse energy of the SPring 8 extreme ultraviolet (EUV) free electron laser (FEL) was measured using a cryogenic radiometer with a relative standard uncertainty of 3%. The temperature change of the cavity in the cryogenic radiometer caused by an incident FEL pulse was determined using a lock-in amplifier and an ac Wheatstone bridge. The measured pulse energies were compared with a gas-monitor detector developed by Physikalisch-Technische Bundesanstalt/Deutsches Elektronen-Synchrotron/Ioffe Physico-Technical Institute (Ioffe) at a wavelength of 51.3 nm at the SPring-8 EUV-FEL in a shot-to-shot mode. The pulse energies measured using the two detectors agree within 2.0%. (authors)

  12. Cannon Fire Soon to Accompany Bugle Call at Fort Detrick | Poster

    Science.gov (United States)

    Beginning June 14, the familiar bugle calls at Fort Detrick will be joined by a special percussion instrument: a cannon. A single cannon shot will be fired on the first note of “Reveille,” which signals the start of each day and is accompanied by the raising of the American flag. “Reveille” sounds at 6:30 a.m. At 5 p.m., Fort Detrick plays “Retreat,” which alerts the post that the flag is about to be lowered. The cannon will fire on the last note of “Retreat.” After a five-second pause, “To the Color” plays as the flag is lowered.

  13. Single-shot photonic time-stretch digitizer using a dissipative soliton-based passively mode-locked fiber laser.

    Science.gov (United States)

    Peng, Di; Zhang, Zhiyao; Zeng, Zhen; Zhang, Lingjie; Lyu, Yanjia; Liu, Yong; Xie, Kang

    2018-03-19

    We demonstrate a single-shot photonic time-stretch digitizer using a dissipative soliton-based passively mode-locked fiber laser. The theoretical analysis and simulation results indicate that the dissipative soliton-based optical source with a flat spectrum relieves the envelope-induced signal distortion, and its high energy spectral density helps to improve the signal-to-noise ratio, both of which are favorable for simplifying the optical front-end architecture of a photonic time-stretch digitizer. By employing a homemade dissipative soliton-based passively mode-locked erbium-doped fiber laser in a single-shot photonic time-stretch digitizer, an effective number of bits of 4.11 bits under an effective sampling rate of 100 GS/s is experimentally obtained without optical amplification in the link and pulse envelope removing process.

  14. Absolute Quantification of Rifampicin by MALDI Imaging Mass Spectrometry Using Multiple TOF/TOF Events in a Single Laser Shot.

    Science.gov (United States)

    Prentice, Boone M; Chumbley, Chad W; Caprioli, Richard M

    2017-01-01

    Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) allows for the visualization of molecular distributions within tissue sections. While providing excellent molecular specificity and spatial information, absolute quantification by MALDI IMS remains challenging. Especially in the low molecular weight region of the spectrum, analysis is complicated by matrix interferences and ionization suppression. Though tandem mass spectrometry (MS/MS) can be used to ensure chemical specificity and improve sensitivity by eliminating chemical noise, typical MALDI MS/MS modalities only scan for a single MS/MS event per laser shot. Herein, we describe TOF/TOF instrumentation that enables multiple fragmentation events to be performed in a single laser shot, allowing the intensity of the analyte to be referenced to the intensity of the internal standard in each laser shot while maintaining the benefits of MS/MS. This approach is illustrated by the quantitative analyses of rifampicin (RIF), an antibiotic used to treat tuberculosis, in pooled human plasma using rifapentine (RPT) as an internal standard. The results show greater than 4-fold improvements in relative standard deviation as well as improved coefficients of determination (R 2 ) and accuracy (>93% quality controls, errors). This technology is used as an imaging modality to measure absolute RIF concentrations in liver tissue from an animal dosed in vivo. Each microspot in the quantitative image measures the local RIF concentration in the tissue section, providing absolute pixel-to-pixel quantification from different tissue microenvironments. The average concentration determined by IMS is in agreement with the concentration determined by HPLC-MS/MS, showing a percent difference of 10.6%. Graphical Abstract ᅟ.

  15. The effect of shot noise on the start up of the fundamental and harmonics in free-electron lasers

    International Nuclear Information System (INIS)

    Freund, H. P.; Miner, W. H. Jr.; Giannessi, L.

    2008-01-01

    The problem of radiation start up in free-electron lasers (FELs) is important in the simulation of virtually all FEL configurations including oscillators and amplifiers in both seeded master oscillator power amplifier (MOPA) and self-amplified spontaneous emission (SASE) modes. Both oscillators and SASE FELs start up from spontaneous emission due to shot noise on the electron beam, which arises from the random fluctuations in the phase distribution of the electrons. The injected power in a MOPA is usually large enough to overwhelm the shot noise. However, this noise must be treated correctly in order to model the initial start up of the harmonics. In this paper, we discuss and compare two different shot noise models that are implemented in both one-dimensional wiggler-averaged (PERSEO) and non-wiggler-averaged (MEDUSA1D) simulation codes, and a three-dimensional non-wiggler-averaged (MEDUSA) formulation. These models are compared for examples describing both SASE and MOPA configurations in one dimension, in steady-state, and time-dependent simulations. Remarkable agreement is found between PERSEO and MEDUSA1D for the evolution of the fundamental and harmonics. In addition, three-dimensional correction factors have been included in the MEDUSA1D and PERSEO, which show reasonable agreement with MEDUSA for a sample MOPA in steady-state and time-dependent simulations

  16. Laser Peening Process and Its Impact on Materials Properties in Comparison with Shot Peening and Ultrasonic Impact Peening

    Science.gov (United States)

    Gujba, Abdullahi K.; Medraj, Mamoun

    2014-01-01

    The laser shock peening (LSP) process using a Q-switched pulsed laser beam for surface modification has been reviewed. The development of the LSP technique and its numerous advantages over the conventional shot peening (SP) such as better surface finish, higher depths of residual stress and uniform distribution of intensity were discussed. Similar comparison with ultrasonic impact peening (UIP)/ultrasonic shot peening (USP) was incorporated, when possible. The generation of shock waves, processing parameters, and characterization of LSP treated specimens were described. Special attention was given to the influence of LSP process parameters on residual stress profiles, material properties and structures. Based on the studies so far, more fundamental understanding is still needed when selecting optimized LSP processing parameters and substrate conditions. A summary of the parametric studies of LSP on different materials has been presented. Furthermore, enhancements in the surface micro and nanohardness, elastic modulus, tensile yield strength and refinement of microstructure which translates to increased fatigue life, fretting fatigue life, stress corrosion cracking (SCC) and corrosion resistance were addressed. However, research gaps related to the inconsistencies in the literature were identified. Current status, developments and challenges of the LSP technique were discussed. PMID:28788284

  17. Optimization of laser energy deposition for single-shot high aspect-ratio microstructuring of thick BK7 glass

    Energy Technology Data Exchange (ETDEWEB)

    Garzillo, Valerio; Grigutis, Robertas [Dipartimento di Scienza e Alta Tecnologia, University of Insubria, Via Valleggio 11, I-22100 Como (Italy); Jukna, Vytautas [Centre de Physique Theorique, CNRS, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau (France); LOA, ENSTA-ParisTech, CNRS, Ecole Polytechnique, Université Paris Saclay, F-91762 Palaiseau (France); Couairon, Arnaud [Centre de Physique Theorique, CNRS, Ecole Polytechnique, Université Paris-Saclay, F-91128 Palaiseau (France); Di Trapani, Paolo [Dipartimento di Scienza e Alta Tecnologia, University of Insubria and CNISM UdR Como, Via Valleggio 11, I-22100 Como (Italy); Jedrkiewicz, Ottavia, E-mail: ottavia.jedrkiewicz@ifn.cnr.it [Istituto di Fotonica e Nanotecnologie, CNR and CNISM UdR Como, Via Valleggio 11, I-22100 Como (Italy)

    2016-07-07

    We investigate the generation of high aspect ratio microstructures across 0.7 mm thick glass by means of single shot Bessel beam laser direct writing. We study the effect on the photoinscription of the cone angle, as well as of the energy and duration of the ultrashort laser pulse. The aim of the study is to optimize the parameters for the writing of a regular microstructure due to index modification along the whole sample thickness. By using a spectrally resolved single pulse transmission diagnostics at the output surface of the glass, we correlate the single shot material modification with observations of the absorption in different portions of the retrieved spectra, and with the absence or presence of spectral modulation. Numerical simulations of the evolution of the Bessel pulse intensity and of the energy deposition inside the sample help us interpret the experimental results that suggest to use picosecond pulses for an efficient and more regular energy deposition. Picosecond pulses take advantage of nonlinear plasma absorption and avoid temporal dynamics effects which can compromise the stationarity of the Bessel beam propagation.

  18. Laser Peening Process and Its Impact on Materials Properties in Comparison with Shot Peening and Ultrasonic Impact Peening

    Directory of Open Access Journals (Sweden)

    Abdullahi K. Gujba

    2014-12-01

    Full Text Available The laser shock peening (LSP process using a Q-switched pulsed laser beam for surface modification has been reviewed. The development of the LSP technique and its numerous advantages over the conventional shot peening (SP such as better surface finish, higher depths of residual stress and uniform distribution of intensity were discussed. Similar comparison with ultrasonic impact peening (UIP/ultrasonic shot peening (USP was incorporated, when possible. The generation of shock waves, processing parameters, and characterization of LSP treated specimens were described. Special attention was given to the influence of LSP process parameters on residual stress profiles, material properties and structures. Based on the studies so far, more fundamental understanding is still needed when selecting optimized LSP processing parameters and substrate conditions. A summary of the parametric studies of LSP on different materials has been presented. Furthermore, enhancements in the surface micro and nanohardness, elastic modulus, tensile yield strength and refinement of microstructure which translates to increased fatigue life, fretting fatigue life, stress corrosion cracking (SCC and corrosion resistance were addressed. However, research gaps related to the inconsistencies in the literature were identified. Current status, developments and challenges of the LSP technique were discussed.

  19. Modifications in morphological, structural, electrical and mechanical properties of Fe-1.0 wt.% Cu alloy on irradiation with 532 nm-6 ns Nd:YAG laser shots

    Science.gov (United States)

    Butt, M. Z.; Ur-Rehman, Khalil; Ali, Dilawar; Aftab, Muzamil; Usman Tanveer, M.

    2017-09-01

    The role of laser irradiation in tailoring the mechanical and electrical properties of Fe-1.0 wt.% Cu alloy has been explored, and compared with that of energetic particle irradiation. Mechanically polished/annealed Fe-1.0 wt.% Cu alloy specimens were irradiated in a vacuum ~10-3 Torr with 1-2500 laser shots. The laser fluence and laser intensity at the laser spot on the target surface were 86.54 J cm-2 and 14.4  ×  109 W cm-2, respectively. Different surface morphological features, e.g. dips, ripples, ridges, nanohillocks, microcones, micropillars, cavities, grooves, nano- and micro-size droplets, as well as tadpole-like structures, etc, were observed by SEM. Surface roughness was maximum for 1 laser shot, decreased by 40% for 250 laser shots, and then reduced by 70% in the range 500-2500. Crystallite size D and lattice strain ɛ were determined by Williamson-Hall analysis of x-ray diffractographs. An increasing linear relationship between electrical resistivity and Vickers hardness was found. In a plot of hardness versus D -1/2, crossover from Hall-Petch to Inverse Hall-Petch relation was observed at a critical value of D  ≈  11 nm. This behaviour was also followed by electrical resistivity. It is established that the nature of microstructural changes produced in the alloy on laser irradiation and on energetic particle irradiation is different.

  20. Single-shot spectro-temporal characterization of XUV pulses from a seeded free-electron laser

    Science.gov (United States)

    de Ninno, Giovanni; Gauthier, David; Mahieu, Benoît; Ribič, Primož Rebernik; Allaria, Enrico; Cinquegrana, Paolo; Danailov, Miltcho Bojanov; Demidovich, Alexander; Ferrari, Eugenio; Giannessi, Luca; Penco, Giuseppe; Sigalotti, Paolo; Stupar, Matija

    2015-08-01

    Intense ultrashort X-ray pulses produced by modern free-electron lasers (FELs) allow one to probe biological systems, inorganic materials and molecular reaction dynamics with nanoscale spatial and femtoscale temporal resolution. These experiments require the knowledge, and possibly the control, of the spectro-temporal content of individual pulses. FELs relying on seeding have the potential to produce spatially and temporally fully coherent pulses. Here we propose and implement an interferometric method, which allows us to carry out the first complete single-shot spectro-temporal characterization of the pulses, generated by an FEL in the extreme ultraviolet spectral range. Moreover, we provide the first direct evidence of the temporal coherence of a seeded FEL working in the extreme ultraviolet spectral range and show the way to control the light generation process to produce Fourier-limited pulses. Experiments are carried out at the FERMI FEL in Trieste.

  1. Internal Ballistics of a Pneumatic Potato Cannon

    Science.gov (United States)

    Mungan, Carl E.

    2009-01-01

    Basic laws of thermodynamics and mechanics are used to analyse an air gun. Such devices are often employed in outdoor physics demonstrations to launch potatoes using compressed gas that is here assumed to expand reversibly and adiabatically. Reasonable agreement is found with reported muzzle speeds for such homebuilt cannons. The treatment is…

  2. Characterization of temporal coherence of hard X-ray free-electron laser pulses with single-shot interferograms

    Directory of Open Access Journals (Sweden)

    Taito Osaka

    2017-11-01

    Full Text Available Temporal coherence is one of the most fundamental characteristics of light, connecting to spectral information through the Fourier transform relationship between time and frequency. Interferometers with a variable path-length difference (PLD between the two branches have widely been employed to characterize temporal coherence properties for broad spectral regimes. Hard X-ray interferometers reported previously, however, have strict limitations in their operational photon energies, due to the specific optical layouts utilized to satisfy the stringent requirement for extreme stability of the PLD at sub-ångström scales. The work presented here characterizes the temporal coherence of hard X-ray free-electron laser (XFEL pulses by capturing single-shot interferograms. Since the stability requirement is drastically relieved with this approach, it was possible to build a versatile hard X-ray interferometer composed of six separate optical elements to cover a wide photon energy range from 6.5 to 11.5 keV while providing a large variable delay time of up to 47 ps at 10 keV. A high visibility of up to 0.55 was observed at a photon energy of 10 keV. The visibility measurement as a function of time delay reveals a mean coherence time of 5.9 ± 0.7 fs, which agrees with that expected from the single-shot spectral information. This is the first result of characterizing the temporal coherence of XFEL pulses in the hard X-ray regime and is an important milestone towards ultra-high energy resolutions at micro-electronvolt levels in time-domain X-ray spectroscopy, which will open up new opportunities for revealing dynamic properties in diverse systems on timescales from femtoseconds to nanoseconds, associated with fluctuations from ångström to nanometre spatial scales.

  3. Shot-noise-limited laser power stabilization with a high-power photodiode array.

    Science.gov (United States)

    Kwee, Patrick; Willke, Benno; Danzmann, Karsten

    2009-10-01

    The output power of a cw Nd:YAG laser was stabilized in a dc-coupled feedback loop with a low-noise multiphotodiode detector and an electro-optic amplitude modulator in the frequency band from 1 Hz to 1 kHz. For the first time, to our knowledge, an independently measured relative power noise of 2.4 x 10(-9) Hz(-1/2) at 10 Hz was achieved, fulfilling the power stability requirements of the Advanced LIGO (Laser Interferometer Gravitational-Wave Observatory) gravitational wave detector.

  4. Direct comparison of shot-to-shot noise performance of all normal dispersion and anomalous dispersion supercontinuum pumped with sub-picosecond pulse fiber-based laser

    Science.gov (United States)

    Klimczak, Mariusz; Soboń, Grzegorz; Kasztelanic, Rafał; Abramski, Krzysztof M.; Buczyński, Ryszard

    2016-01-01

    Coherence of supercontinuum sources is critical for applications involving characterization of ultrafast or rarely occurring phenomena. With the demonstrated spectral coverage of supercontinuum extending from near-infrared to over 10 μm in a single nonlinear fiber, there has been a clear push for the bandwidth rather than for attempting to optimize the dynamic properties of the generated spectrum. In this work we provide an experimental assessment of the shot-to-shot noise performance of supercontinuum generation in two types of soft glass photonic crystal fibers. Phase coherence and intensity fluctuations are compared for the cases of an anomalous dispersion-pumped fiber and an all-normal dispersion fiber. With the use of the dispersive Fourier transformation method, we demonstrate that a factor of 100 improvement in signal-to-noise ratio is achieved in the normal-dispersion over anomalous dispersion-pumped fiber for 390 fs long pump pulses. A double-clad design of the photonic lattice of the fiber is further postulated to enable a pump-related seeding mechanism of normal-dispersion supercontinuum broadening under sub-picosecond pumping, which is otherwise known for similar noise characteristics as modulation instability driven, soliton-based spectra. PMID:26759188

  5. FLASH free-electron laser single-shot temporal diagnostic: terahertz-field-driven streaking.

    Science.gov (United States)

    Ivanov, Rosen; Liu, Jia; Brenner, Günter; Brachmanski, Maciej; Düsterer, Stefan

    2018-01-01

    The commissioning of a terahertz-field-driven streak camera installed at the free-electron laser (FEL) FLASH at DESY in Hamburg, being able to deliver photon pulse duration as well as arrival time information with ∼10 fs resolution for each single XUV FEL pulse, is reported. Pulse durations between 300 fs and terahertz-streaking setup was operated simultaneously to an alternative method to determine the FEL pulse duration based on spectral analysis. FLASH pulse duration derived from simple spectral analysis is in good agreement with that from terahertz-streaking measurement.

  6. Single-shot measurements of low emittance beams from laser-plasma accelerators comparing two triggered injection methods

    Science.gov (United States)

    van Tilborg, Jeroen

    2017-10-01

    The success of laser plasma accelerator (LPA) based applications, such as a compact x-ray free electron laser (FEL), relies on the ability to produce electron beams with excellent 6D brightness, where brightness is defined as the ratio of charge to the product of the three normalized emittances. As such, parametric studies of the emittance of LPA generated electron beams are essential. Profiting from a stable and tunable LPA setup, combined with a carefully designed single-shot energy-dispersed emittance diagnostic, we present a direct comparison of charge dependent emittance measurements of electron beams generated by two different injection mechanisms: ionization injection and shock-induced density down-ramp injection. Both injection mechanisms have gained in popularity in recent years due to their demonstrated stable LPA performance. For the down-ramp injection configuration, normalized emittances a factor of two lower were recorded: less than 1 micron at spectral charge densities up to 2 pC/MeV. For both injection mechanisms, a contributing correlation of space charge to the emittance was identified. This measurement technique in general, and these results specifically, are critical to the evaluation of LPA injection methods and development of high-quality LPA beam lines worldwide. This work is supported by the U.S. DOE under Contract No. DE-AC02-05CH11231, by the U.S. DOE NNSA, DNN R&D (NA22), by the National Science Foundation under Grant No. PHY-1415596, and by the Gordon and Betty Moore Foundation under Grant ID GBMF4898.

  7. Single-shot beam-position monitor for x-ray free electron laser

    Science.gov (United States)

    Tono, Kensuke; Kudo, Togo; Yabashi, Makina; Tachibana, Takeshi; Feng, Yiping; Fritz, David; Hastings, Jerome; Ishikawa, Tetsuya

    2011-02-01

    We have developed an x-ray beam-position monitor for detecting the radiation properties of an x-ray free electron laser (FEL). It is composed of four PIN photodiodes that detect backscattered x-rays from a semitransparent diamond film placed in the beam path. The signal intensities from the photodiodes are used to compute the beam intensity and position. A proof-of-principle experiment at a synchrotron light source revealed that the error in the beam position is reduced to below 7 μm by using a nanocrystal diamond film prepared by plasma-enhanced chemical vapor deposition. Owing to high dose tolerance and transparency of the diamond film, the monitor is suitable for routine diagnostics of extremely intense x-ray pulses from the FEL.

  8. Development of twin cannons of thermal plasma

    International Nuclear Information System (INIS)

    Pena E, R.

    1996-01-01

    Today several service and transformation industries that generate hazardous wastes must implement programs in order to fulfill with requirements established by the present standardization. This problem is solved here for proposing the design and construction of a thermal plasma transferred torch with double cannon which is generated by an electric arc with a capacity of 50 k W, a regulable gas flow from 0-50 lt./min and thermal yield higher than 85 %. This equipment would be capable for degradating industrial and hospital wastes. (Author)

  9. Shot Automation for the National Ignition Facility

    International Nuclear Information System (INIS)

    Lagin, L J; Bettenhausen, R C; Beeler, R G; Bowers, G A; Carey, R.; Casavant, D.D.; Cline, B.D.; Demaret, R.D.; Domyancic, D.M.; Elko, S.D.; Fisher, J.M.; Hermann, M.R.; Krammen, J.E.; Kohut, T.R.; Marshall, C.D.; Mathisen, D.G.; Ludwigsen, A.P.; Patterson, Jr. R.W.; Sanchez, R.J.; Stout, E.A.; Van Arsdall, P.J.; Van Wonterghem, B.M.

    2005-01-01

    A shot automation framework has been developed and deployed during the past year to automate shots performed on the National Ignition Facility (NIF) using the Integrated Computer Control System This framework automates a 4-8 hour shot sequence, that includes inputting shot goals from a physics model, set up of the laser and diagnostics, automatic alignment of laser beams and verification of status. This sequence consists of set of preparatory verification shots, leading to amplified system shots using a 4-minute countdown, triggering during the last 2 seconds using a high-precision timing system, followed by post-shot analysis and archiving. The framework provides for a flexible, model-based execution driven of scriptable automation called macro steps. The framework is driven by high-level shot director software that provides a restricted set of shot life cycle state transitions to 25 collaboration supervisors that automate 8-laser beams (bundles) and a common set of shared resources. Each collaboration supervisor commands approximately 10 subsystem shot supervisors that perform automated control and status verification. Collaboration supervisors translate shot life cycle state commands from the shot director into sequences of ''macro steps'' to be distributed to each of its shot supervisors. Each Shot supervisor maintains order of macro steps for each subsystem and supports collaboration between macro steps. They also manage failure, restarts and rejoining into the shot cycle (if necessary) and manage auto/manual macro step execution and collaborations between other collaboration supervisors. Shot supervisors execute macro step shot functions commanded by collaboration supervisors. Each macro step has database-driven verification phases and a scripted perform phase. This provides for a highly flexible methodology for performing a variety of NIF shot types. Database tables define the order of work and dependencies (workflow) of macro steps to be performed for a

  10. Wavefront Analysis of Nonlinear Self-Amplified Spontaneous-Emission Free-Electron Laser Harmonics in the Single-Shot Regime

    Energy Technology Data Exchange (ETDEWEB)

    Bachelard, R.; Chubar, O.; Mercere, P.; Idir, M.; Couprie, M.E.; Lambert, G.; Zeitoun, Ph.; Kimura, H.; Ohashi, H.; Higashiya, A.; Yabashi, M.; Nagasono, M.; Hara, T. and Ishikawa, T.

    2011-06-08

    The single-shot spatial characteristics of the vacuum ultraviolet self-amplified spontaneous emission of a free electron laser (FEL) is measured at different stages of amplification up to saturation with a Hartmann wavefront sensor. We show that the fundamental radiation at 61.5 nm tends towards a single-mode behavior as getting closer to saturation. The measurements are found in good agreement with simulations and theory. A near diffraction limited wavefront was measured. The analysis of Fresnel diffraction through the Hartmann wavefront sensor hole array also provides some further insight for the evaluation of the FEL transverse coherence, of high importance for various applications.

  11. Future Combat Systems (FCS) Creates Cannon and Mortar Synergy

    National Research Council Canada - National Science Library

    Beard, Kirby; James, Jeff; Tolbert, Vincent J

    2008-01-01

    .... The NLOS-C is one of the eight MGVs. Program Manager FCS (Brigade Combat Team (PM FCS(BCT)) is leveraging previous and current research and development efforts to create synergy between cannons and mortars, without duplication of effort...

  12. Infrared-spectroscopic single-shot laser mapping ellipsometry: Proof of concept for fast investigations of structured surfaces and interactions in organic thin films

    Science.gov (United States)

    Furchner, Andreas; Kratz, Christoph; Gkogkou, Dimitra; Ketelsen, Helge; Hinrichs, Karsten

    2017-11-01

    We present a novel infrared-spectroscopic laser mapping ellipsometer based on a single-shot measurement concept. The ellipsometric set-up employs multiple analyzers and detectors to simultaneously measure the sample's optical response under different analyzer azimuths. An essential component is a broadly tunable quantum cascade laser (QCL) covering the important marker region of 1800-1540 cm-1. The ellipsometer allows for fast single-wavelength as well as spectroscopic studies with thin-film sensitivity at temporal resolutions of 60 ms per wavelength. We applied the single-shot mapping ellipsometer for the characterization of metal-island enhancement surfaces as well as of molecular interactions in organic thin films. In less than 3 min, a linescan with 1600 steps revealed profile and infrared-enhancement properties of a gradient gold-island film for sensing applications. Spectroscopic measurements were performed to probe the amide I band of thin films of poly(N-isopropylacrylamide) [PNIPAAm], a stimuli-responsive polymer for bioapplications. The QCL spectra agree well with conventional FT-IR ellipsometric results, showing different band components associated with hydrogen-bond interactions between polymer and adsorbed water. Multi-wavelength ellipsometric maps were used to analyze homogeneity and surface contaminations of the polymer films.

  13. Broadband femtosecond OPCPA system driven by the single-shot narrow-band iodine photodissociation laser SOFIA

    Czech Academy of Sciences Publication Activity Database

    Novák, Ondřej; Turčičová, Hana; Smrž, Martin; Huynh, Jaroslav; Pfeifer, Miroslav; Straka, Petr

    2012-01-01

    Roč. 108, č. 3 (2012), s. 501-508 ISSN 0946-2171 R&D Projects: GA ČR GA202/06/0814; GA MŠk(CZ) LC528 EU Projects: European Commission(XE) 506350 - LASER LAB-EUROPE Institutional research plan: CEZ:AV0Z10100523 Keywords : OPCPA * ultrashort laser pulses * optical parametric amplifiers * Iodine laser s * gas laser s * nonlinear optical crystals, * petawatt laser s Subject RIV: BH - Optics, Masers, Laser s Impact factor: 1.782, year: 2012 http://www.springerlink.com/content/5l263x8722204606/

  14. One-shot deep-UV pulsed-laser-induced photomodification of hollow metal nanoparticles for high-density data storage on flexible substrates.

    Science.gov (United States)

    Wan, Dehui; Chen, Hsuen-Li; Tseng, Shao-Chin; Wang, Lon A; Chen, Yung-Pin

    2010-01-26

    In this paper, we report a new optical data storage method: photomodification of hollow gold nanoparticle (HGN) monolayers induced by one-shot deep-ultraviolet (DUV) KrF laser recording. As far as we are aware, this study is the first to apply HGNs in optical data storage and also the first to use a recording light source for the metal nanoparticles (NPs) that is not a surface plasmon resonance (SPR) wavelength. The short wavelength of the recording DUV laser improved the optical resolution dramatically. We prepared HGNs exhibiting two absorbance regions: an SPR peak in the near-infrared (NIR) region and an intrinsic material extinction in the DUV region. A single pulse from a KrF laser heated the HGNs and transformed them from hollow structures to smaller solid spheres. This change in morphology for the HGNs was accompanied by a significant blue shift of the SPR peak. Employing this approach, we demonstrated its patterning ability with a resolving power of a half-micrometer (using a phase mask) and developed a readout method (using a blue-ray laser microscope). Moreover, we prepared large-area, uniform patterns of monolayer HGNs on various substrates (glass slides, silicon wafers, flexible plates). If this spectral recording technique could be applied onto thin flexible tapes, the recorded data density would increase significantly relative to that of current rigid discs (e.g., compact discs).

  15. Indirect monitoring shot-to-shot shock waves strength reproducibility during pump–probe experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pikuz, T. A., E-mail: tatiana.pikuz@eie.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 Japan (Japan); Photon Pioneers Center, Osaka University, Suita, Osaka 565-0871 Japan (Japan); Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Faenov, A. Ya. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Institute for Academic Initiatives, Osaka University, Suita, Osaka 565-0871 (Japan); Ozaki, N.; Habara, H.; Tanaka, K. A.; Kodama, R. [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 Japan (Japan); Photon Pioneers Center, Osaka University, Suita, Osaka 565-0871 Japan (Japan); Hartley, N. J.; Matsuoka, T. [Institute for Academic Initiatives, Osaka University, Suita, Osaka 565-0871 (Japan); Albertazzi, B.; Matsuyama, S.; Yamauchi, K.; Ochante, R. [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 Japan (Japan); Takahashi, K.; Sueda, K. [Photon Pioneers Center, Osaka University, Suita, Osaka 565-0871 Japan (Japan); Tange, Y. [Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan); Sakata, O. [Synchrotron X-ray Station at SPring-8, NIMS, Sayo, Hyogo 679-5148 (Japan); Sekine, T.; Sato, T.; Umeda, Y. [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Inubushi, Y. [Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan); RIKEN Spring-8 Center, Sayo, Hyogo 679-5148 Japan (Japan); and others

    2016-07-21

    We present an indirect method of estimating the strength of a shock wave, allowing on line monitoring of its reproducibility in each laser shot. This method is based on a shot-to-shot measurement of the X-ray emission from the ablated plasma by a high resolution, spatially resolved focusing spectrometer. An optical pump laser with energy of 1.0 J and pulse duration of ∼660 ps was used to irradiate solid targets or foils with various thicknesses containing Oxygen, Aluminum, Iron, and Tantalum. The high sensitivity and resolving power of the X-ray spectrometer allowed spectra to be obtained on each laser shot and to control fluctuations of the spectral intensity emitted by different plasmas with an accuracy of ∼2%, implying an accuracy in the derived electron plasma temperature of 5%–10% in pump–probe high energy density science experiments. At nano- and sub-nanosecond duration of laser pulse with relatively low laser intensities and ratio Z/A ∼ 0.5, the electron temperature follows T{sub e} ∼ I{sub las}{sup 2/3}. Thus, measurements of the electron plasma temperature allow indirect estimation of the laser flux on the target and control its shot-to-shot fluctuation. Knowing the laser flux intensity and its fluctuation gives us the possibility of monitoring shot-to-shot reproducibility of shock wave strength generation with high accuracy.

  16. Measurement of the X-ray Spectrum of a Free Electron Laser with a Wide-Range High-Resolution Single-Shot Spectrometer

    Directory of Open Access Journals (Sweden)

    Yuichi Inubushi

    2017-06-01

    Full Text Available We developed a single-shot X-ray spectrometer for wide-range high-resolution measurements of Self-Amplified Spontaneous Emission (SASE X-ray Free Electron Laser (XFEL pulses. The spectrometer consists of a multi-layer elliptical mirror for producing a large divergence of 22 mrad around 9070 eV and a silicon (553 analyzer crystal. We achieved a wide energy range of 55 eV with a fine spectral resolution of 80 meV, which enabled the observation of a whole SASE-XFEL spectrum with fully-resolved spike structures. We found that a SASE-XFEL pulse has around 60 longitudinal modes with a pulse duration of 7.7 ± 1.1 fs.

  17. Single-shot soft x-ray laser-induced ablative microstructuring of organic polymer with demagnifying projection

    Czech Academy of Sciences Publication Activity Database

    Mocek, Tomáš; Rus, Bedřich; Kozlová, Michaela; Polan, Jiří; Homer, Pavel; Juha, Libor; Hájková, Věra; Chalupský, Jaromír

    2008-01-01

    Roč. 33, č. 10 (2008), s. 1087-1089 ISSN 0146-9592 R&D Projects: GA AV ČR KAN300100702; GA ČR GA202/05/2316; GA MŠk LC510; GA MŠk(CZ) LC528; GA MŠk LA08024 Institutional research plan: CEZ:AV0Z10100523 Keywords : x-ray lasers * laser ablation * microstructuring Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.772, year: 2008

  18. Allergy Shots (For Parents)

    Science.gov (United States)

    ... animal dander. Allergy shots are not useful for food allergies. When receiving allergy shots, a child may experience ... Allergies First Aid: Allergic Reactions Insect Sting Allergy Food Allergies Serious Allergic Reactions (Anaphylaxis) Word! Allergy Word! Allergy ...

  19. Shot peening speed measurements using lidar technology

    DEFF Research Database (Denmark)

    Angelou, Nikolas; Zhang, Xiaodan; Sjöholm, Mikael

    The shot peening technique is used for the surface modification of metallic components that are part of wind turbines, such as gears, bolts and blade coatings to prevent erosion. An important parameter of this technique is the dynamic energy of emitted shots. In this context the objective...... of this project is to present a proof of concept measurement method for the evaluation of the speed of the shots. A remote sensing laser anemometer was selected as a probing instrument of the peening shots’ speed since it avoids any disturbances to the flow from the presence of an in-situ instrument. Furthermore...

  20. Birth Control Shot

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Birth Control Shot KidsHealth / For Teens / Birth Control Shot What's in this article? What Is ... español La inyección anticonceptiva What Is It? The birth control shot is a long-acting form of ...

  1. Synchronizing single-shot high-energy iodine photodissociation laser PALS and high-repetition-rate femtosecond Ti:sapphire laser system

    Czech Academy of Sciences Publication Activity Database

    Dostál, Jan; Dudžák, Roman; Pisarczyk, T.; Pfeifer, Miroslav; Huynh, Jaroslav; Chodukowski, T.; Kalinowska, Z.; Krouský, E.; Skála, J.; Hřebíček, Jan; Medřík, Tomáš; Golasowski, Jiří; Juha, Libor; Ullschmied, J.

    2017-01-01

    Roč. 88, č. 4 (2017), s. 1-11, č. článku 045109. ISSN 0034-6748 Institutional support: RVO:68378271 Keywords : oscillators * plasma diagnostics * optical signal processing * mode locking * laser amplifiers Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.515, year: 2016

  2. Synchronizing single-shot high-energy iodine photodissociation laser PALS and high-repetition-rate femtosecond Ti:sapphire laser system

    Czech Academy of Sciences Publication Activity Database

    Dostál, Jan; Dudžák, Roman; Pisarczyk, T.; Pfeifer, Miroslav; Huynh, J.; Chodukowski, T.; Kalinowska, Z.; Krouský, Eduard; Skála, Jiří; Hřebíček, Jan; Medřík, Tomáš; Golasowski, Jiří; Juha, Libor; Ullschmied, Jiří

    2017-01-01

    Roč. 88, č. 4 (2017), č. článku 045109. ISSN 0034-6748 R&D Projects: GA MŠk LM2010014; GA MŠk(CZ) LM2015083; GA ČR GPP205/11/P712 Institutional support: RVO:61389021 Keywords : oscillators * plasma diagnostics * optical signal processing * mode locking * laser amplifiers Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: 2.11 Other engineering and technologies Impact factor: 1.515, year: 2016 https://aip.scitation.org/doi/10.1063/1.4979810

  3. Unacknowledged contributions of Pavlov and Barcroft to Cannon's theory of homeostasis.

    Science.gov (United States)

    Smith, Gerard P

    2008-11-01

    Cannon's theory of homeostasis is the first, major, American contribution to physiological thought. Although it is clear that Cannon's account of homeostasis is personal and based primarily on the work of his laboratory, Cannon made it easy for readers to mistake his 1929 paper and 1932 book for a comprehensive review of the literature relevant to homeostasis. This is unfortunate because Cannon never acknowledged the important contributions of two of his contemporaries, Ivan Pavlov and Joseph Barcroft. Since he did not mention them, their contributions are rarely discussed. This paper attempts to correct this historical problem in two ways. First, I describe the unacknowledged contributions of Pavlov and Barcroft. Then I consider the possible reasons why Cannon ignored them.

  4. Shot-put kinematics

    Science.gov (United States)

    DeLuca, R.

    2005-11-01

    The problem of the optimum throw in the shot-put discipline is analysed by relaxing the assumption that the height H, from which the athlete releases the shot, does not depend on the angle θ which the arm of the putter makes with the horizontal axis. In this context, the kinematics of the shot-put is studied and results are compared with the traditional analysis, which considers the height H, the angle θ and the modulus V0 of the initial velocity of the metal sphere as independent parameters.

  5. Ensemble Cannonical Correlation Prediction of Seasonal Precipitation Over the US

    Science.gov (United States)

    Lau, William K. M.; Kim, Kyu-Myong; Shen, Samuel; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This paper presents preliminary results of an ensemble cannonical correlation (ECC) prediction scheme developed at the Climate and Radiation Branch, NASA/Goddard Space Flight Center for determining the potential predictability of regional precipitation, and for climate downscaling studies. The scheme is tested on seasonal hindcasts of anomalous precipitation over the continental United States using global sea surface temperature (SST) for 1951-2000. To maximize the forecast skill derived from SST, the world ocean is divided into nonoverlapping sectors. The cannonical SST modes for each sector are used as the predictor for the ensemble hindcasts. Results show that the ECC yields a substantial (10-25%) increase in prediction skills for all regions of the US and for all seasonal compared to traditional CCA prediction schemes. For the boreal winter, the tropical Pacific contributes the largest potential predictability to precipitation in the southwestern and southeastern regions, while the North Pacific and the North Atlantic are responsible for enhanced forecast skills in the Pacific Northwest, the northern Great Plains and Ohio Valley. Most importantly, the ECC increases skill for summertime precipitation prediction and substantially reduced the spring predictability barrier over all regions of the US continent. Besides SST, the ECC is designed with the flexibility to include any number of predictor fields, such as soil moisture, snow cover and regional regional data. Moreover, the ECC forecasts can be applied to other climate subsystems and, in conjunction with further diagnostic or model studies will enables a better understanding of the dynamic links between climate variations and precipitation, not only for the US, but also for other regions of the world.

  6. Get Important Shots

    Science.gov (United States)

    ... or older adults Work in a school, hospital, prison, or health clinic Travel outside the United States ... health care reform law passed in 2010, most private insurance plans must cover recommended shots for adults. ...

  7. Artillery Through the Ages. A Short Illustrated History of Cannon, Emphasizing Types Used in America

    National Research Council Canada - National Science Library

    Manucy, Albert

    1962-01-01

    .... Section 1 focuses on the Era of Artillery and includes chapters on The Ancient Engines of War, Gunpowder Comes to Europe, The Bombards, Sixteenth Century Cannon, The Seventeenth Century and Gustavus...

  8. Lessons Learned on the Application of Vibration Absorbers for Enhanced Cannon Stabilization

    Directory of Open Access Journals (Sweden)

    Eric Kathe

    2001-01-01

    Full Text Available This paper will summarize the successful application of muzzle-end vibration absorbers to reduce cannon vibration. This technology constitutes a weapons stabilization approach that focuses on passive mechanical structural modification of the cannon, rather than relying upon an external control law to actively cancel vibrations. Challenges encountered during field testing, non-ideal behavior, and performance evaluation using digital signal processing will be highlighted.

  9. SnapShot:Macropinocytosis.

    Science.gov (United States)

    Marques, Pedro E; Grinstein, Sergio; Freeman, Spencer A

    2017-05-04

    Macropinocytosis is the bulk ingestion of extracellular fluids via large endocytic vacuoles. This SnapShot provides an overview of physiological macropinocytosis in immune surveillance and its pathogenic contribution during infection and cancer proliferation. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Kids Guide to Shots

    Science.gov (United States)

    ... First Aid & Safety Doctors & Hospitals Videos Recipes for Kids Kids site Sitio para niños How the Body ... Safe Videos for Educators Search English Español A Kid's Guide to Shots KidsHealth / For Kids / A Kid's ...

  11. ZAPP shot summary

    Energy Technology Data Exchange (ETDEWEB)

    Loisel, Guillaume Pascal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-01

    This was the second Z Astrophysical Plasma Properties (ZAPP) fundamental science shot series of 2015. ZAPP experiments measure fundamental properties of atoms in plasmas to solve the following important astrophysical puzzles: Why can’t we accurately model the opacity of Fe at the convection zone boundary in the Sun? How accurate are the photoionization models used to interpret data from xray satellite observations? and Why doesn’t spectral fitting provide the correct properties for White Dwarfs?

  12. The Cannonical process of sanctity from Santa Rosa de Lima (new lights on the local identity of the Colonial Peru

    Directory of Open Access Journals (Sweden)

    Teodoro Hampe Martínez

    2018-02-01

    Full Text Available Trought the exam of the cannonical process of sanctity of Isabel Flores de Oliva (Santa Rosa de Lima, the first person born in América and admitted between the saints by the church, the author describes the society of Lima at the end of the XVIIth century and the importance of this cannonical process for the emergent local society.

  13. Non-Line-of-Sight Cannon (NLOS-C) System Crew Shock Loading, Evaluation of Potential Head and Neck Injury

    National Research Council Canada - National Science Library

    LaFiandra, Michael E; Zywiol, Harry

    2007-01-01

    The Future Combat Systems (FCS) non-line of sight cannon (NLOS-C) is an artillery weapon that will use a 155-mm cannon that will be capable of automatically firing and reloading ammunition, as many as six rounds per minute...

  14. One-shot synesthesia

    Directory of Open Access Journals (Sweden)

    Kirschner Alexandra

    2017-11-01

    Full Text Available Synesthesia is commonly thought to be a phenomenon of fixed associations between an outside inducer and a vivid concurrent experience. Hence, it has been proposed that synesthesia occurs due to additional connections in the brain with which synesthetes are born. Here we show that synesthesia can be a much richer and more flexible phenomenon with a capability to creatively construct novel synesthetic experiences as events unfold in people’s lives. We describe here cases of synesthetes who occasionally generate novel synesthetic experience, called one-shot synesthesias. These synesthetic experiences seem to share all the properties with the classical synesthetic associations except that they occur extremely rarely, people recalling only a few events over the lifetime. It appears that these one-shots are not created at random but are instead responses to specific life events. We contrast the properties of those rare synesthetic events with other, more commonly known forms of synesthesia that also create novel synesthetic experiences, but at a high rate—sometimes creating novel experiences every few seconds. We argue that one-shot synesthesias indicate that synesthetic associations are by their nature not prewired at birth but are dynamically constructed through mental operations and according to the needs of a synesthetic mind. Our conclusions have implications for understanding the biological underpinnings of synesthesia and the role the phenomenon plays in the lives of people endowed with synesthetic capacities.

  15. Experimental study of EUV mirror radiation damage resistance under long-term free-electron laser exposures below the single-shot damage threshold

    Czech Academy of Sciences Publication Activity Database

    Makhotkin, I.; Sobierajski, R.; Chalupský, Jaromír; Tiedtke, K.; de Vries, G.; Stoermer, M.; Scholze, F.; Siewert, F.; van de Kruijs, R.W.E.; Milov, I.; Louis, E.; Jacyna, I.; Jurek, M.; Klinger, D.; Nittler, L.; Syryanyy, Y.; Juha, Libor; Hájková, Věra; Vozda, Vojtěch; Burian, Tomáš; Saksl, Karel; Faatz, B.; Keitel, B.; Ploenjes, E.; Schreiber, S.; Toleikis, S.; Loch, R.A.; Hermann, M.; Strobel, S.; Nienhuys, H.-K.; Gwalt, G.; Mey, T.; Enkisch, H.

    2018-01-01

    Roč. 25, č. 1 (2018), s. 77-84 ISSN 1600-5775. [Workshop on FEL Photon Diagnostics, Instrumentation and Beamline Design (PhotonDiag2017). Stanford, 01.05.2017-03.05.2017] R&D Projects: GA MŠk LG15013; GA ČR(CZ) GA17-05167s; GA ČR(CZ) GA14-29772S Institutional support: RVO:68378271 Keywords : free-electron laser induced damage * EUV optics * thin films * FELs Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.011, year: 2016

  16. A High-Power Laser-Driven Source of Sub-nanosecond Soft X-Ray Pulses for Single-Shot Radiobiology Experiments

    Czech Academy of Sciences Publication Activity Database

    Davídková, Marie; Juha, Libor; Bittner, Michal; Koptyaev, Sergey; Hájková, Věra; Krása, Josef; Pfeifer, Miroslav; Štísová, Viktorie; Bartnik, A.; Fiedorowicz, H.; Mikolajczyk, J.; Ryc, L.; Pína, L.; Horváth, M.; Babánková, Dagmar; Cihelka, Jaroslav; Civiš, Svatopluk

    2007-01-01

    Roč. 168, č. 3 (2007), s. 382-387 ISSN 0033-7587 R&D Projects: GA ČR GA202/05/2316; GA MŠk(CZ) LC528; GA MŠk 1P04LA235; GA MŠk LC510 Institutional research plan: CEZ:AV0Z10480505; CEZ:AV0Z10100523; CEZ:AV0Z20430508; CEZ:AV0Z40400503 Keywords : soft X-rays * radiation damage to DNA * laser-driven source Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.599, year: 2007

  17. Mode-Locked Multichromatic X-Rays in a Seeded Free-Electron Laser for Single-Shot X-Ray Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Dao; Ding, Yuantao; Raubenheimer, Tor; Wu, Juhao; /SLAC

    2012-05-10

    We present the promise of generating gigawatt mode-locked multichromatic x rays in a seeded free-electron laser (FEL). We show that, by using a laser to imprint periodic modulation in electron beam phase space, a single-frequency coherent seed can be amplified and further translated to a mode-locked multichromatic output in an FEL. With this configuration the FEL output consists of a train of mode-locked ultrashort pulses which span a wide frequency gap with a series of equally spaced sharp lines. These gigawatt multichromatic x rays may potentially allow one to explore the structure and dynamics of a large number of atomic states simultaneously. The feasibility of generating mode-locked x rays ranging from carbon K edge ({approx}284 eV) to copper L{sub 3} edge ({approx}931 eV) is confirmed with numerical simulation using the realistic parameters of the linac coherent light source (LCLS) and LCLS-II. We anticipate that the mode-locked multichromatic x rays in FELs may open up new opportunities in x-ray spectroscopy (i.e. resonant inelastic x-ray scattering, time-resolved scattering and spectroscopy, etc.).

  18. The Physics of Shot Towers

    Science.gov (United States)

    Lipscombe, Trevor C.; Mungan, Carl E.

    2012-01-01

    In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: "How does the size of the lead shot depend on the height…

  19. Validation of CFD simulation of recoilless EOD water cannon by firing experiments with high speed camera

    Science.gov (United States)

    Chantrasmi, Tonkid; Hongthong, Premsiri; Kongkaniti, Manop

    2018-01-01

    Water cannon used by Explosive Ordnance Disposal (EOD) were designed to propel a burst of water jet moving at high speed to target and disrupt an improvised explosive device (IED). The cannon could be mounted on a remotely controlled robot, so it is highly desirable for the cannon to be recoilless in order not to damage the robot after firing. In the previous work, a nonconventional design of the water cannon was conceived. The recoil was greatly reduced by backward sprays of water through a ring of slotted holes around the muzzle. This minimizes the need to manufacture new parts by utilizing all off-the-shelf components except the tailor-made muzzle. The design was then investigated numerically by a series of Computational Fluid Dynamics (CFD) simulations. In this work, high speed camera was employed in firing experiments to capture the motion of the water jet and the backward sprays. It was found that the experimental data agreed well with the simulation results in term of averaged exit velocities.

  20. Buster-Jangle Shot Dog

    International Nuclear Information System (INIS)

    Kaul, Dean C.

    1987-01-01

    Shot Dog of the Buster-Jangle Series used a device which had a high-explosive configuration virtually identical to that of the Nagasaki bomb, though with different fissionable components. Dog was detonated at a height of 431.9 m with the mean atmospheric conditions between burst and ground being dry air density 1.027 mg/cc and atmospheric moisture density 0.006 mg/cc. The ground was taken to be that of Nevada test site (NTS) area 9 with a water content of 8% by weight. The yield of the weapon was 21 kt. Results shown here for Buster-Jangle Shot Dog have been scaled from those calculated for Ranger Shot Fox. The design features and burst geometries of the two devices were deemed sufficiently similar to make this substitution in the absence of a radiation leakage spectrum calculated explicitly for Buster-Jangle Shot Dog. However, while the relative atmospheric contents of the two shots were very similar, Shot Fox took place in air of approximately 10% greater density than Shot Dog. Thus, scaled calculated results could not be obtained to compare with the three closest measurement points at Shot Dog

  1. Shot Noise in Gravitational-Wave Detectors with Fabry-Perot Arms

    OpenAIRE

    Lyons, Torrey T.; Regehr, Martin W.; Raab, Frederick J.

    2000-01-01

    Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry–Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian–French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the ...

  2. Shot noise in gravitational-wave detectors with Fabry-Perot arms.

    Science.gov (United States)

    Lyons, T T; Regehr, M W; Raab, F J

    2000-12-20

    Shot-noise-limited sensitivity is calculated for gravitational-wave interferometers with Fabry-Perot arms, similar to those being installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Italian-French Laser Interferometer Collaboration (VIRGO) facility. This calculation includes the effect of nonstationary shot noise that is due to phase modulation of the light. The resulting formula is experimentally verified by a test interferometer with suspended mirrors in the 40-m arms.

  3. Rust formed on cannons of XVIII century under two environment conditions

    International Nuclear Information System (INIS)

    Cindra Fonseca, M.P.; Bastos, I.N.; Caytuero, A.; Baggio Saitovitch, E.M.

    2007-01-01

    The corrosion products of two ancient cannons exposed to atmospheric corrosion were analysed by X-ray powder diffraction, transmission Moessbauer spectroscopy and scanning electron microscopy (SEM). After almost three centuries exposed in marine environment one of them was moved to a rural region and was maintained in this environment for approximately 30 years. The inland region has an altitude of 1000 m above sea level and consequently low aggressiveness. The studied rusts were obtained from external and internal surfaces of the cannon barrels. This investigation, using three different techniques, was done to check if the relatively short time (ca. 30 years) in rural area was sufficient to change the characteristics of the thick rust formed during long time exposure (ca. 300 years) in marine atmosphere. The time-environment effects change the physical nature of rust, mainly observed by Moessbauer spectroscopy results

  4. Environmental Impact Statement. Preliminary Draft. Realignment of Cannon Air Force Base, Curry County, New Mexico

    Science.gov (United States)

    1989-12-15

    shooting, poisoning, wounding, killing, capturing, trapping, collecting, molesting , or disturbing of these birds. The Migratory Bird Conservation Act...matter less than 10 microns in diameter, a size range which is more lik-,ely to cause respiratory problems when inhaled. The old TSP standard is...levels in the vicinity of Cannon AFB is in terms of the DNL, which is the method adopted by the Environmental Protection Agency (EPA), the Department of

  5. Generalised shot noise Cox processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Torrisi, Giovanni Luca

    We introduce a new class of Cox cluster processes called generalised shot-noise processes (GSNCPs), which extends the definition of shot noise Cox processes (SNCPs) in two directions: the point process which drives the shot noise is not necessarily Poisson, and the kernel of the shot noise can...... be random. Thereby a very large class of models for aggregated or clustered point patterns is obtained. Due to the structure of GSNCPs, a number of useful results can be established. We focus first on deriving summary statistics for GSNCPs and next on how to make simulation for GSNCPs. Particularly, results...... for first and second order moment measures, reduced Palm distributions, the -function, simulation with or without edge effects, and conditional simulation of the intensity function driving a GSNCP are given. Our results are exemplified for special important cases of GSNCPs, and we discuss the relation...

  6. Generalised shot noise Cox processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Torrisi, Giovanni Luca

    2005-01-01

    We introduce a class of cox cluster processes called generalised shot noise Cox processes (GSNCPs), which extends the definition of shot noise Cox processes (SNCPs) in two directions: the point process that drives the shot noise is not necessarily Poisson, and the kernel of the shot noise can...... be random. Thereby, a very large class of models for aggregated or clustered point patterns is obtained. Due to the structure of GSNCPs, a number of useful results can be established. We focus first on deriving summary statistics for GSNCPs and, second, on how to simulate such processes. In particular......, results on first- and second-order moment measures, reduced Palm distributions, the J-function, simulation with or without edge effects, and conditional simulation of the intensity function driving a GSNCP are given. Our results are exemplified in important special cases of GSNCPs, and we discuss...

  7. Shot peening of aluminium alloys

    International Nuclear Information System (INIS)

    Le Guernic, Y.

    1998-01-01

    Shot peening is a process of cold-hammering where a metallic surface is pelted with spherical grains. Each grain bumping into the surface acts as a hammer head and creates a small crater. The overlapping of these craters produces a residual compression layer just underneath the surface. It is well known that cracks cannot spread in a compression zone. In most cases of fatigue rupture and stress corrosion cracks propagate from the surface towards the inside so shot peening allows a longer lifetime of castings. Moreover most materials present a better resistance due to the cold-hammering effect of shot peening. Metallic surfaces can be treated in workshops or directly on site. Typical pieces that undergo shot peening on site are storing tanks, gas and steam turbines, tubes of steam generators and piping in oil or nuclear or chemical industries. This article describes shot peening from a theoretical and general point of view and presents the application to aluminium-lithium alloys. In the case of aluminium alloys shot peening can be used to shape the piece (peen-forming). (A.C.)

  8. Single-shot 35 fs temporal resolution electron shadowgraphy

    Energy Technology Data Exchange (ETDEWEB)

    Scoby, C. M.; Li, R. K.; Threlkeld, E.; To, H.; Musumeci, P. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095 (United States)

    2013-01-14

    We obtain single-shot time-resolved shadowgraph images of the electromagnetic fields resulting from the interaction of a high intensity ultrashort laser pulse with a metal surface. Using a high brightness relativistic electron beam and a high streaking speed radiofrequency deflector, we report <35 fs temporal resolution enabling a direct visualization of the retarded-time dominated field evolution which follows the laser-induced charge emission. A model including the finite signal propagation speed well reproduces the data and yields measurements of fundamental parameters in short pulse laser-matter interaction such as the amount of emitted charge and the emission time scale.

  9. Light field driven streak-camera for single-shot measurements of the temporal profile of XUV-pulses from a free-electron laser; Lichtfeld getriebene Streak-Kamera zur Einzelschuss Zeitstrukturmessung der XUV-Pulse eines Freie-Elektronen Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Fruehling, Ulrike

    2009-10-15

    The Free Electron Laser in Hamburg (FLASH) is a source for highly intense ultra short extreme ultraviolet (XUV) light pulses with pulse durations of a few femtoseconds. Due to the stochastic nature of the light generation scheme based on self amplified spontaneous emission (SASE), the duration and temporal profile of the XUV pulses fluctuate from shot to shot. In this thesis, a THz-field driven streak-camera capable of single pulse measurements of the XUV pulse-profile has been realized. In a first XUV-THz pump-probe experiment at FLASH, the XUV-pulses are overlapped in a gas target with synchronized THz-pulses generated by a new THz-undulator. The electromagnetic field of the THz light accelerates photoelectrons produced by the XUV-pulses with the resulting change of the photoelectron momenta depending on the phase of the THz field at the time of ionisation. This technique is intensively used in attosecond metrology where near infrared streaking fields are employed for the temporal characterisation of attosecond XUV-Pulses. Here, it is adapted for the analysis of pulse durations in the few femtosecond range by choosing a hundred times longer far infrared streaking wavelengths. Thus, the gap between conventional streak cameras with typical resolutions of hundreds of femtoseconds and techniques with attosecond resolution is filled. Using the THz-streak camera, the time dependent electric field of the THz-pulses was sampled in great detail while on the other hand the duration and even details of the time structure of the XUV-pulses were characterized. (orig.)

  10. Laser Transmitter for the Lunar Orbit Laser Altimeter (LOLA) Instrument

    Science.gov (United States)

    Yu, Anthony W.; Novo-Gradac, Anne-Marie; Shaw, George B.; Li, Steven X.; Krebs, Danny C.; Ramos-Izquierdo, Luis A.; Unger, Glenn; Lukemire, Alan

    2008-01-01

    We present the final configuration of the space flight laser transmitter as delivered to the LOLA instrument. The laser consists of two oscillators on a single bench, each capable of providing one billion plus shots.

  11. The lunar orbiter laser altimeter (LOLA) laser transmitter

    Science.gov (United States)

    Yu, Anthony W.; Novo-Gradac, Anne Marie; Shaw, George B.; Unger, Glenn; Ramos-Izquierdo, Luis A.; Lukemire, Alan

    2008-02-01

    We present the final configuration of the space flight laser transmitter as delivered to the LOLA instrument. The laser consists of two oscillators with co-aligned outputs on a single bench, each capable of providing one billion plus shots.

  12. Optimisation of water-cannon cleaning for deposit removal on water walls inside waste incinerators.

    Science.gov (United States)

    Graube, Franziska; Grahl, Sebastian; Rostkowski, Slawomir; Beckmann, Michael

    2016-02-01

    Deposits in municipal waste incinerators are very inhomogeneous in structure and constitution. They cause corrosion and reduce the efficiency, so they need to be removed frequently. Among other systems, operators use water cannons for the deposit removal. Two different removal mechanisms of water-cannon cleaning are suggested: A direct shattering of the deposit by the impact of the water jet, as well as the cracking caused by thermal stresses where droplets cool the deposits. As the contribution of each of the aforementioned mechanisms to the overall cleaning efficiency is unknown, we performed empirical investigations to determine the dominating effect. In a first experimental setup focusing on thermal stress, cold droplets were applied onto hot deposits taken from a waste incinerator. Results showed that the cleaning effect strongly depends on the deposit thickness and structure, so that the deposits could be categorised in three different groups. A second measurement campaign focused on the influence of deposit material, deposit temperature and water jet momentum. It could be shown that both deposit material and temperature have a significant effect on the cleaning efficiency, whereas an increase in water jet momentum only led to modest improvements. The combination of these two parameter studies implies that the influence of the thermal stress outweighs that of the momentum. This knowledge is applicable to the cleaning setup by increasing the temperature gradient. © The Author(s) 2015.

  13. Assembly procedure for Shot Loading Platform

    International Nuclear Information System (INIS)

    Routh, R.D.

    1995-01-01

    This supporting document describes the assembly procedure for the Shot Loading Platform. The Shot Loading Platform is used by multiple equipment removal projects to load shielding shot in the annular spaces of the equipment storage containers. The platform height is adjustable to accommodate different sizes of storage containers and transport assemblies

  14. 7 CFR 51.904 - Shot berries.

    Science.gov (United States)

    2010-01-01

    ... Standards for Grades of Table Grapes (European or Vinifera Type) 1 Definitions § 51.904 Shot berries. Shot berries means very small berries resulting from insufficient pollination, usually seedless in those... 7 Agriculture 2 2010-01-01 2010-01-01 false Shot berries. 51.904 Section 51.904 Agriculture...

  15. 50 CFR 20.134 - Nontoxic shot.

    Science.gov (United States)

    2010-10-01

    ... shot (negative control), or the candidate shot or coated shot. Fluoroscope birds at 1 week after dosage... and 30, collect blood by venipuncture, determine hematocrit, hemoglobin concentration and other.... Provide body weight and blood parameter measurements on samples drawn at 24 hours after dosage and at the...

  16. Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes

    Science.gov (United States)

    Zhai, Zhao-Hui; Zhong, Sen-Cheng; Li, Jun; Zhu, Li-Guo; Meng, Kun; Li, Jiang; Liu, Qiao; Peng, Qi-Xian; Li, Ze-Ren; Zhao, Jian-Heng

    2016-09-01

    Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ˜400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

  17. Rotary peening with captive shot

    International Nuclear Information System (INIS)

    1998-02-01

    Roto Peen with captive shot removes coatings and surface contamination from concrete floors. The objective of treating radioactively contaminated concrete floors during the Deactivation and Decommissioning (D and D) process is to reduce the surface contamination levels to meet regulatory criteria for unrestricted use. The US Department of Energy (DOE) Chicago Operations office and DOE's Federal Energy Technology Center (FETC) jointly sponsored a Large-Scale Demonstration Project (LSDP) at the Chicago Pile-5 Research Reactor (CP-5) at Argonne National Laboratory-East (ANL). The objective of the LSDP is to demonstrate potentially beneficial D and D technologies in comparison with current baseline technologies. As part of the LSDP, roto Peen with captive shot was demonstrated March 17--20, 1997, to treat a 20 x 25 ft area of radioactively contaminated concrete floor on the service level of the CP-5 building

  18. The Problem of Shot Selection in Basketball

    Science.gov (United States)

    Skinner, Brian

    2012-01-01

    In basketball, every time the offense produces a shot opportunity the player with the ball must decide whether the shot is worth taking. In this article, I explore the question of when a team should shoot and when they should pass up the shot by considering a simple theoretical model of the shot selection process, in which the quality of shot opportunities generated by the offense is assumed to fall randomly within a uniform distribution. Within this model I derive an answer to the question “how likely must the shot be to go in before the player should take it?” and I show that this lower cutoff for shot quality depends crucially on the number of shot opportunities remaining (say, before the shot clock expires), with larger demanding that only higher-quality shots should be taken. The function is also derived in the presence of a finite turnover rate and used to predict the shooting rate of an optimal-shooting team as a function of time. The theoretical prediction for the optimal shooting rate is compared to data from the National Basketball Association (NBA). The comparison highlights some limitations of the theoretical model, while also suggesting that NBA teams may be overly reluctant to shoot the ball early in the shot clock. PMID:22295109

  19. The problem of shot selection in basketball.

    Directory of Open Access Journals (Sweden)

    Brian Skinner

    Full Text Available In basketball, every time the offense produces a shot opportunity the player with the ball must decide whether the shot is worth taking. In this article, I explore the question of when a team should shoot and when they should pass up the shot by considering a simple theoretical model of the shot selection process, in which the quality of shot opportunities generated by the offense is assumed to fall randomly within a uniform distribution. Within this model I derive an answer to the question "how likely must the shot be to go in before the player should take it?" and I show that this lower cutoff for shot quality f depends crucially on the number n of shot opportunities remaining (say, before the shot clock expires, with larger n demanding that only higher-quality shots should be taken. The function f(n is also derived in the presence of a finite turnover rate and used to predict the shooting rate of an optimal-shooting team as a function of time. The theoretical prediction for the optimal shooting rate is compared to data from the National Basketball Association (NBA. The comparison highlights some limitations of the theoretical model, while also suggesting that NBA teams may be overly reluctant to shoot the ball early in the shot clock.

  20. Increasing shot and data collection rates of the Shock/Shear experiment at the National Ignition Facility

    International Nuclear Information System (INIS)

    Doss, F. W.; Flippo, K. A.; Capelli, D.; Cardenas, T.; DeVolder, B.; Kline, J.; Kot, L.; Kurien, S.; Loomis, E.; Merritt, E. C.; Perry, T.; Schmidt, D.; Di Stefano, C.

    2016-01-01

    Updates to the Los Alamos laser-driven high-energy-density Shock/Shear mixing- layer experiment are reported, which have collectively increased the platform's shot and data acquisition rates. The strategies employed have included a move from two-strip to four-strip imagers (allowing four times to be recorded per shot instead of two), the implementation of physics-informed rules of engagements allowing for the maximum flexibility in a shot's total energy and symmetry performance, and splitting the laser's main drive pulse from a monolithic single pulse equal to all beams into a triply-segmented pulse which minimizes optics damage. (paper)

  1. The single-shot opto-digitizer

    International Nuclear Information System (INIS)

    Nail, M.; Gibert, Ph.

    2000-01-01

    Laser-plasma experiments need to measure signals provided either by X-ray, photonic or neutronic detector. The measurement should have 50 GHz bandwidth and up to several hundred of Giga-Hertz for sub picosecond plasmas. For this purpose, a 35 GHz single shot opto-digitizer (10 ps risetime) has been studied and built. The device is made up of a 50 ohms microstrip propagation line, periodically lined by 100 sampled gates. The propagation line is long enough to measure a 400 ps duration. The sampling rate is 250 Gsa/s (every 4 ps). The sampled gates are made with fast recombining photo-material and turn on by a subpicosecond laser pulse which is synchronized exactly with the analysed phenomena. Every gate is recording to a storing capacitor. After the recording, every capacitor charge is needed to built the signal that was displayed on the propagation line. The dynamic range of measurement is 47 for the entire device. The device can measure positive or negative signals from 1.5 to 70 Volts. To increase the bandwidth, two another kinds of opto-digitizer were studied: one is a buried stripline with 56 GHz band width, the other a 70 GHz coplanar transmission line. For the purpose of subpicosecond plasmas, a 30 coplanar waveguide opto-digitizer was studied. Characteristics are as followed: window of measurement 40 ps, sampling rate 1 ps, bandwidth 230 GHz. Finally, a bundle of optical fibers was used to propagate the laser beam on semiconductor gates. If the gates are lighted at the same time, i.e. if the optical fibers have the same length, we get a simultaneous addressing. By using different lengths of optical fibers, we can do a sequential addressing. So, the sampling rate becomes a combination of the distance between two adjacent sampled channels, and the difference in length of optical fibers. (author)

  2. Semantic Shot Classification in Sports Video

    Science.gov (United States)

    Duan, Ling-Yu; Xu, Min; Tian, Qi

    2003-01-01

    In this paper, we present a unified framework for semantic shot classification in sports videos. Unlike previous approaches, which focus on clustering by aggregating shots with similar low-level features, the proposed scheme makes use of domain knowledge of a specific sport to perform a top-down video shot classification, including identification of video shot classes for each sport, and supervised learning and classification of the given sports video with low-level and middle-level features extracted from the sports video. It is observed that for each sport we can predefine a small number of semantic shot classes, about 5~10, which covers 90~95% of sports broadcasting video. With the supervised learning method, we can map the low-level features to middle-level semantic video shot attributes such as dominant object motion (a player), camera motion patterns, and court shape, etc. On the basis of the appropriate fusion of those middle-level shot classes, we classify video shots into the predefined video shot classes, each of which has a clear semantic meaning. The proposed method has been tested over 4 types of sports videos: tennis, basketball, volleyball and soccer. Good classification accuracy of 85~95% has been achieved. With correctly classified sports video shots, further structural and temporal analysis, such as event detection, video skimming, table of content, etc, will be greatly facilitated.

  3. Cannon de Hermeto Pascoal: aspectos musicais e religiosos em uma obra-prima para flauta Cannon by Hermeto Pascoal: musical and religious aspects in a flute masterpiece

    Directory of Open Access Journals (Sweden)

    Fausto Borém

    2010-12-01

    Full Text Available Estudo de caso sobre Cannon de Hermeto Pascoal, obra para flauta, humming na flauta e sons pré-gravados, planejada como uma sessão espírita musical e gravada pelo compositor no disco Slaves Mass (PASCOAL, 1977. A partir do desenho artístico de uma pauta espiralada na capa interna do mesmo LP (PASCOAL e PEREIRA, 1977 e de uma transcrição baseada na faixa gravada, a partitura da obra foi detalhadamente reconstituída e editada (PASCOAL e BORÉM, 2010; incluída neste volume de Per Musi às p.80-82. A combinação das análises formal, escalar e proporcional da partitura e seu cruzamento com a análise espectral da gravação revelam grande unidade e uma íntima relação entre os conteúdos musicais e extra-musicais da obra, na qual elementos opostos dialogam: a improvisação e as camadas de superposição de sons pré-gravados, a sonoridade acústica e os sons manipulados, a performance individual e a coletiva, a estabilidade e a instabilidade modal, as linguagens popular (embolada, jazz modal, free jazz e erudita (música concreta, atonalismo, cadenza, recitativo, os mundos terreno e espiritual. Apresenta também, em primeira mão, a abordagem analítica do "continuum separação-fusão paradoxal" da obra, a partir de ferramenta etnomusicológica criada e realizada por COSTA-LIMA NETO (2009. Inclui uma contextualização do papel da religião na música do "mago" multi-instrumentista, arranjador e compositor da música popular brasileira.Case study on Cannon by Brazilian composer, arranger and multi-instrumentalist Hermeto Pascoal, a work for flute, flute humming and pre-recorded sounds, designed as a musical spiritism session and included in the LP Slaves Mass (PASCOAL, 1977. Departing from an artistic drawing of a music staff spiral included in the internal covers of the same LP (PASCOAL e PEREIRA, 1977 and a transcription based on the listening of the track in the same disc, the score of the work was reconstituted and edited in detail

  4. Shot peening: theory applications and recent development

    International Nuclear Information System (INIS)

    Zaid, A.I.O.

    1999-01-01

    Shot peening is a surface treatment process by which the surface of an elastic-plastic target material is subjected to multiple impact by spherical shots made of glass or hard steel in a defined and controlled manner. The multiple impact produces a dynamic compressive stress at the surface of the target, thereby effectively improving its mechanical behavior and eliminates cracks and imperfections hence improving the fatigue life and strength. In this paper, the theory and practice of the shot peening process are reviewed. The main parameters involved in the process and their effects on shot peening are presented and discussed which include: shot material, size and geometry, shot pressure and shot velocity, projection angle, exposure time, table rotational speed, standoff distance coverage, saturation and peening intensity. Furthermore, the effect of shot peening on fatigue life and fatigue strength of ferrous and non-ferrous materials together with other different industrial applications of the process are given. Recent developments in utilizing the shot peening process with welded parts and hard chromium plating aiming at improvement of their fatigue strength and their resistance to stress corrosion cracking are also presented and discussed. Finally, future development of the process are outlined and discussed. (author)

  5. Shot noise in radiobiological systems.

    Science.gov (United States)

    Datesman, A

    2016-11-01

    As a model for human tissue, this report considers the rate of free radical generation in a dilute solution of water in which a beta-emitting radionuclide is uniformly dispersed. Each decay dissipates a discrete quantity of energy, creating a large number of free radicals in a short time within a small volume determined by the beta particle range. Representing the instantaneous dissipated power as a train of randomly-spaced pulses, the time-averaged dissipated power p¯ and rate of free radical generation g¯ are derived. The analogous result in the theory of electrical circuits is known as the shot noise theorem. The reference dose of X-rays D ref producing an identical rate of free radical generation and level of oxidative stress is shown a) to increase with the square root of the absorbed dose, D, and b) to be far larger than D. This finding may have important consequences for public health in cases where the level of shot noise exceeds some noise floor corresponding to equilibrium biological processes. An estimate of this noise floor is made using the example of potassium-40, a beta-emitting radioisotope universally present in living tissue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. SunShot Initiative Portfolio Book 2014

    Energy Technology Data Exchange (ETDEWEB)

    Solar Energy Technologies Office

    2014-05-01

    The 2014 SunShot Initiative Portfolio Book outlines the progress towards the goals outlined in the SunShot Vision Study. Contents include overviews of each of SunShot’s five subprogram areas, as well as a description of every active project in the SunShot’s project portfolio as of May 2014.

  7. The killing efficiency of soft iron shot

    Science.gov (United States)

    Andrews, R.; Longcore, J.R.

    1969-01-01

    A cooperative research effort between the ammunition industry and the Bureau of Sport Fisheries and Wildlife is aimed at finding a suitable non-toxic substitute for lead shot. A contract study by an independent research organization evaluated ways of coating or detoxifying lead shot or replacing it with another metal. As a result of that study, the only promising candidate is soft iron. Previous tests of hard iron shot had suggested that its killing effectiveness was poor at longer ranges due to the lower density. In addition, its hardness caused excessive damage to shotgun barrels. A unique, automated shooting facility was constructed at the Patuxent Wildlife Research Center to test the killing effectiveness of soft iron shot under controlled conditions. Tethered game-farm mallards were transported across a shooting point in a manner simulating free flight. A microswitch triggered a mounted shotgun so that each shot was 'perfect.' A soft iron shot, in Number 4 size, was produced by the ammunition industry and loaded in 12-gauge shells to give optimum ballistic performance. Commercial loads of lead shot in both Number 4 and Number 6 size were used for comparison. A total of 2,010 ducks were shot at ranges of 30 to 65 yards and at broadside and head-on angles in a statistically designed procedure. The following data were recorded for each duck: time until death, broken wing or leg bones, and number of embedded shot. Those ducks not killed outright were held for 10 days. From these data, ducks were categorized as 'probably bagged,' 'probably lost cripples,' or survivors. The test revealed that the killing effectiveness of this soft iron shot was superior to its anticipated performance and close to that obtained with commercial lead loads containing an equal number of pellets. Bagging a duck, in terms of rapid death or broken wing, was primarily dependent on the probability of a shot striking that vital area, and therefore a function of range. There was no indication

  8. A review on the basketball jump shot.

    Science.gov (United States)

    Okazaki, Victor H A; Rodacki, André L F; Satern, Miriam N

    2015-06-01

    The ability to shoot an effective jump shot in the sport of basketball is critical to a player's success. In an attempt to better understand the aspects related to expert performance, researchers have investigated successful free throws and jump shots of various basketball players and identified movement variables that contribute to their success. The purpose of this study was to complete a systematic review of the scientific literature on the basketball free throw and jump shot for the purpose of revealing the critical components of shooting that coaches, teachers, and players should focus on when teaching, learning, practising, and performing a jump shot. The results of this review are presented in three sections: (a) variables that affect ball trajectory, (b) phases of the jump shot, and (c) additional variables that influence shooting.

  9. Shot noise limit of the optical 3D measurement methods for smooth surfaces

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Pavel; Pech, Miroslav

    2016-01-01

    Roč. 27, č. 3 (2016), 1-7, č. článku 035205. ISSN 0957-0233 R&D Projects: GA ČR GA13-12301S Institutional support: RVO:68378271 Keywords : measurement uncertainty * shot noise * 3D measurement * interferometry Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.585, year: 2016

  10. Moulded interconnect device fabrication by two shot molding and lasert induced selective activation

    DEFF Research Database (Denmark)

    Sun, Jie; Hansen, Hans Nørgaard

    , comparative process analysis, applications and specially two shot injection molding and laser induced selective activation in the MID area. There is also an experimental part which contains fabrication of a MID demonstrator, selective metallization as well as characterization. The realization of molded...

  11. Single shot damage mechanism of Mo/Si multilayer optics under intense pulsed XUV-exposures

    NARCIS (Netherlands)

    Khorsand, A.R.; Sobierajski, R.; Louis, Eric; Bruijn, S.; Gleeson, A.; van de Kruijs, Robbert Wilhelmus Elisabeth; Gullikson, E.M.; Bijkerk, Frederik

    2010-01-01

    We investigated single shot damage of Mo/Si multilayer coatings exposed to the intense fs XUV radiation at the Free-electron LASer facility in Hamburg - FLASH. The interaction process was studied in situ by XUV reflectometry, time resolved optical microscopy, and “post-mortem” by

  12. Influence of Shot Peening on Failure of an Aluminum Alloy Exposed to Aggressive Aqueous Environments

    Science.gov (United States)

    Lv, Shengli; Cu, You; Zhang, Wei; Tong, Xiaoyan; Srivatsan, T. S.; Gao, Xiaosheng

    2013-06-01

    Pre-corrosion damage tests were performed on the high strength aluminum alloy (Al-Zn-Mg-Cu) that was subject to shot peening surface treatment. The tests were performed for different time levels and compared one-on-one with the performance and characteristics of the non-shot-peened alloy. The residual stress induced by the shot peening surface treatment for two different intensity levels was measured using the method of incremental drilling of holes. Based on an observation of morphology of corrosion experienced by the aluminum alloy the depth of corrosion was measured using a laser displacement sensor. The surface of the aluminum alloy that was shot peened revealed an overall better resistance to pitting while concurrently revealing evidence of partial degradation. The depth of degradation is related to the residual stress that is induced in the aluminum alloy sample by the shot peening treatment. The key mechanisms that control damage during corrosion of the shot-peened aluminum alloy can be divided into the distinct stages of (a) initial occurrence of uniform corrosion followed by (b) the generation of degradation, and (c) culminating in the initiation of pitting once the depth of degradation reaches a certain level.

  13. Active-passively mode-locked dye laser for diagnosis of laser-produced plasmas

    International Nuclear Information System (INIS)

    Teng, Y.L.; Fedosejevs, R.; Sigel, R.

    1981-03-01

    In this report an active-passively mode-locked, flashlamp-pumped dye laser for diagnosis of laser-produced plasmas is described. This dye laser system used as a pulsed light source for high-speed photography of laser-target experiments was synchronized to the ASTERIX III iodine laser pulse with better than 100 ps accuracy. The single pulse energy was 10 μJ, pulse duration less than 10 ps. In 111 shots clear shadowgrams were obtained during a total of 151 target shots, i.e. the system worked well in 74% of the shots. (orig.)

  14. Basketball shot types and shot success in different levels of competitive basketball.

    Directory of Open Access Journals (Sweden)

    Frane Erčulj

    Full Text Available The purpose of our research was to investigate the relative frequencies of different types of basketball shots (above head, hook shot, layup, dunk, tip-in, some details about their technical execution (one-legged, two-legged, drive, cut, …, and shot success in different levels of basketball competitions. We analysed video footage and categorized 5024 basketball shots from 40 basketball games and 5 different levels of competitive basketball (National Basketball Association (NBA, Euroleague, Slovenian 1st Division, and two Youth basketball competitions. Statistical analysis with hierarchical multinomial logistic regression models reveals that there are substantial differences between competitions. However, most differences decrease or disappear entirely after we adjust for differences in situations that arise in different competitions (shot location, player type, and attacks in transition. Differences after adjustment are mostly between the Senior and Youth competitions: more shots executed jumping or standing on one leg, more uncategorised shot types, and more dribbling or cutting to the basket in the Youth competitions, which can all be attributed to lesser technical and physical ability of developing basketball players. The two discernible differences within the Senior competitions are that, in the NBA, dunks are more frequent and hook shots are less frequent compared to European basketball, which can be attributed to better athleticism of NBA players. The effect situational variables have on shot types and shot success are found to be very similar for all competitions.

  15. Basketball Shot Types and Shot Success in Different Levels of Competitive Basketball

    Science.gov (United States)

    2015-01-01

    The purpose of our research was to investigate the relative frequencies of different types of basketball shots (above head, hook shot, layup, dunk, tip-in), some details about their technical execution (one-legged, two-legged, drive, cut, …), and shot success in different levels of basketball competitions. We analysed video footage and categorized 5024 basketball shots from 40 basketball games and 5 different levels of competitive basketball (National Basketball Association (NBA), Euroleague, Slovenian 1st Division, and two Youth basketball competitions). Statistical analysis with hierarchical multinomial logistic regression models reveals that there are substantial differences between competitions. However, most differences decrease or disappear entirely after we adjust for differences in situations that arise in different competitions (shot location, player type, and attacks in transition). Differences after adjustment are mostly between the Senior and Youth competitions: more shots executed jumping or standing on one leg, more uncategorised shot types, and more dribbling or cutting to the basket in the Youth competitions, which can all be attributed to lesser technical and physical ability of developing basketball players. The two discernible differences within the Senior competitions are that, in the NBA, dunks are more frequent and hook shots are less frequent compared to European basketball, which can be attributed to better athleticism of NBA players. The effect situational variables have on shot types and shot success are found to be very similar for all competitions. PMID:26038836

  16. Basketball shot types and shot success in different levels of competitive basketball.

    Science.gov (United States)

    Erčulj, Frane; Štrumbelj, Erik

    2015-01-01

    The purpose of our research was to investigate the relative frequencies of different types of basketball shots (above head, hook shot, layup, dunk, tip-in), some details about their technical execution (one-legged, two-legged, drive, cut, …), and shot success in different levels of basketball competitions. We analysed video footage and categorized 5024 basketball shots from 40 basketball games and 5 different levels of competitive basketball (National Basketball Association (NBA), Euroleague, Slovenian 1st Division, and two Youth basketball competitions). Statistical analysis with hierarchical multinomial logistic regression models reveals that there are substantial differences between competitions. However, most differences decrease or disappear entirely after we adjust for differences in situations that arise in different competitions (shot location, player type, and attacks in transition). Differences after adjustment are mostly between the Senior and Youth competitions: more shots executed jumping or standing on one leg, more uncategorised shot types, and more dribbling or cutting to the basket in the Youth competitions, which can all be attributed to lesser technical and physical ability of developing basketball players. The two discernible differences within the Senior competitions are that, in the NBA, dunks are more frequent and hook shots are less frequent compared to European basketball, which can be attributed to better athleticism of NBA players. The effect situational variables have on shot types and shot success are found to be very similar for all competitions.

  17. Shot-Noise Limited Time-Encoded Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Sebastian Karpf

    2017-01-01

    Full Text Available Raman scattering, an inelastic scattering mechanism, provides information about molecular excitation energies and can be used to identify chemical compounds. Albeit being a powerful analysis tool, especially for label-free biomedical imaging with molecular contrast, it suffers from inherently low signal levels. This practical limitation can be overcome by nonlinear enhancement techniques like stimulated Raman scattering (SRS. In SRS, an additional light source stimulates the Raman scattering process. This can lead to orders of magnitude increase in signal levels and hence faster acquisition in biomedical imaging. However, achieving a broad spectral coverage in SRS is technically challenging and the signal is no longer background-free, as either stimulated Raman gain (SRG or loss (SRL is measured, turning a sensitivity limit into a dynamic range limit. Thus, the signal has to be isolated from the laser background light, requiring elaborate methods for minimizing detection noise. Here, we analyze the detection sensitivity of a shot-noise limited broadband stimulated time-encoded Raman (TICO-Raman system in detail. In time-encoded Raman, a wavelength-swept Fourier domain mode locking (FDML laser covers a broad range of Raman transition energies while allowing a dual-balanced detection for lowering the detection noise to the fundamental shot-noise limit.

  18. Effect of Shot Peening in Different Shot Distance and Shot Angle on Surface Morphology, Surface Roughness and Surface Hardness of 316L Biomaterial

    Science.gov (United States)

    Umbu Kondi Maliwemu, Erich; Malau, Viktor; Iswanto, Priyo Tri

    2018-01-01

    Shot peening is a mechanical surface treatment with a beneficial effect to generate compressive residual stress caused by plastic deformation on the surface of material. This plastic deformation can improve the surface characteristics of metallic materials, such as modification of surface morphology, surface roughness, and surface hardness. The objective of this study is to investigate the effect of shot peening in different shot distance and shot angle on surface morphology, surface roughness, and surface hardness of 316L biomaterial. Shot distance was varied at 6, 8, 10, and 12 cm and shot angle at 30, 60, and 90°, working pressure at 7 kg/cm2, shot duration for 20 minutes, and using steel balls S-170 with diameter of 0.6 mm. The results present that the shot distance and shot angle of shot peening give the significant effect to improve the surface morphology, surface roughness, and surface hardness of 316 L biomaterial. Shot peening can increase the surface roughness by the increasing of shot distance and by the decreasing of shot angle. The nearest shot distance (6 cm) and the largest shot angle (90°) give the best results on the grain refinement with the surface roughness of 1.04 μm and surface hardness of 534 kg/mm2.

  19. Hunting shot – evolution of manufacturing technology

    Directory of Open Access Journals (Sweden)

    Piotr Bochyński

    2016-09-01

    Full Text Available Hunting shot are 1.2–10 mm diameter balls, usually made of lead alloys, forming a cluster projectile used in smoothbore hunting shotguns. Shot may also be used in pistol and revolver ammunition, in which it can constitute structural element of the projectile. Shot pellets may also be made of other materials and have other shapes. The aim of this paper is to aggregate information on the topic available from a number of different sources. It is hoped that such information will be useful for forensic ballistics experts. Historical development of pellets and their manufacturing technology from the 15th century is presented.

  20. Between Shots TRANSP Web Service

    Science.gov (United States)

    Feibush, E.; Andre, R.; Ludescher-Furth, C.; Kaye, S.; McCune, D.

    2008-11-01

    Running TRANSP between NSTX shots requires rapid data preparation and job submittal. A web service with a graphical user interface and data visualization has been developed to meet these goals. The underlying data preparation system has a command line interface written in Python and runs on a PPPL compute server. The display client is a Java program (ElVis) that sends requests to the data preparation system. As the run data is prepared, graphs are created and sent to the client for display. Flux surface plots are displayed and animated over time. The most commonly used control options are implemented in the UI as buttons and text fields. A time slice or time dependent run can be prepared. The command line interface is available in the client program for expert users to apply advanced settings, to prototype new UI buttons, and to run scripts. The client program contains a simple text editor for modifying the TRANSP namelist. When data preparation is complete the run is submitted to the TRANSP production system. The initial version has been deployed and is being tested in the control room setting. Results will be discussed in the poster presentation. Work performed at PPPL under the auspices of U.S. DOE Contract DE-AC02-76CH03073.

  1. Pregnant Women Need a Flu Shot

    Science.gov (United States)

    Pregnant? You Need a Flu Shot! Information for pregnant women Because you are pregnant, CDC and your ob- ... more likely to get severely ill from flu. Pregnant women who get flu are at high risk of ...

  2. (308 nm) excimer laser

    Indian Academy of Sciences (India)

    have been found to be 2 × 106 shots for 20% reduction of energy without any halogen ... Excimer laser; xenon chloride; discharge pumped; C–C energy ... Construction. The cross sectional view of the laser system and the photograph of the developed system are shown in figures 1 and 2, respectively. The system mainly ...

  3. Lasers

    OpenAIRE

    Passeron, Thierry

    2012-01-01

    International audience; Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be succesfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-aulait macules should not b...

  4. Laser

    OpenAIRE

    Du, K.; Loosen, P.; Herziger, G.

    1991-01-01

    Laser, consisting of a beam path multiple-folded by means of two cavity end mirrors and having at least one reflector folding the laser beam retroreflectively, the axis of which is arranged offset in parallel to the axis of a further reflector. So that the laser exhibits an improved beam quality while retaining its comparatively low adjustment sensitivity, the beam path is folded at least twice by means of the retoreflective reflector.

  5. Damage in solids irradiated by a single shot of XUV free-electron laser: irreversible changes investigated using X-ray microdiffraction, atomic force microscopy and Nomarski optical microscopy

    Czech Academy of Sciences Publication Activity Database

    Pelka, J. B.; Sobierajski, R.; Klinger, D.; Paszkowicz, W.; Krzywinski, J.; Jurek, M.; Zymierska, D.; Wawro, A.; Petroutchik, A.; Juha, Libor; Hájková, Věra; Cihelka, Jaroslav; Chalupský, Jaromír; Burian, T.; Vyšín, Luděk; Toleikis, S.; Sokolowski-Tinten, K.; Stojanovic, N.; Zastrau, U.; London, R.; Hau-Riege, S.; Riekel, C.; Davies, R.; Burghammer, M.; Dynowska, E.; Szuszkiewicz, W.; Caliebe, W.; Nietubyc, R.

    2009-01-01

    Roč. 78, Suppl. 10 (2009), S46-S52 ISSN 0969-806X R&D Projects: GA AV ČR KAN300100702; GA MŠk LC510; GA MŠk(CZ) LC528; GA MŠk LA08024; GA AV ČR IAA400100701 Institutional research plan: CEZ:AV0Z10100523 Keywords : XUV FEL * radiation damage * ablation * structure modifications * x-ray diffraction Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.149, year: 2009

  6. Imaging cold atoms with shot-noise and diffraction limited holography

    International Nuclear Information System (INIS)

    Sobol, J P; Wu, Saijun

    2014-01-01

    We theoretically develop and experimentally demonstrate a holographic method for imaging cold atoms at the diffraction and photon shot noise limits. Aided by a double point source reference field, a simple iterative algorithm robustly removes the twin image of an 87 Rb cold atom sample during the image reconstruction. Shot-noise limited phase shift and absorption images are consistently retrieved at various probe detunings, and during the laser cooling process. We consistently resolve less than 2 mrad phase shift (0.4% attenuation) of the probe light, outperforming shot-noise limited phase-contrast (absorption) imaging by a factor of 4 or more if the same camera is used without pixel saturation. We discuss the possible extension of this work for precise phase imaging of dense atomic gases, and for off-resonant probing of multiple atoms in optical lattices. (paper)

  7. Streamflow distribution maps for the Cannon River drainage basin, southeast Minnesota, and the St. Louis River drainage basin, northeast Minnesota

    Science.gov (United States)

    Smith, Erik A.; Sanocki, Chris A.; Lorenz, David L.; Jacobsen, Katrin E.

    2017-12-27

    Streamflow distribution maps for the Cannon River and St. Louis River drainage basins were developed by the U.S. Geological Survey, in cooperation with the Legislative-Citizen Commission on Minnesota Resources, to illustrate relative and cumulative streamflow distributions. The Cannon River was selected to provide baseline data to assess the effects of potential surficial sand mining, and the St. Louis River was selected to determine the effects of ongoing Mesabi Iron Range mining. Each drainage basin (Cannon, St. Louis) was subdivided into nested drainage basins: the Cannon River was subdivided into 152 nested drainage basins, and the St. Louis River was subdivided into 353 nested drainage basins. For each smaller drainage basin, the estimated volumes of groundwater discharge (as base flow) and surface runoff flowing into all surface-water features were displayed under the following conditions: (1) extreme low-flow conditions, comparable to an exceedance-probability quantile of 0.95; (2) low-flow conditions, comparable to an exceedance-probability quantile of 0.90; (3) a median condition, comparable to an exceedance-probability quantile of 0.50; and (4) a high-flow condition, comparable to an exceedance-probability quantile of 0.02.Streamflow distribution maps were developed using flow-duration curve exceedance-probability quantiles in conjunction with Soil-Water-Balance model outputs; both the flow-duration curve and Soil-Water-Balance models were built upon previously published U.S. Geological Survey reports. The selected streamflow distribution maps provide a proactive water management tool for State cooperators by illustrating flow rates during a range of hydraulic conditions. Furthermore, after the nested drainage basins are highlighted in terms of surface-water flows, the streamflows can be evaluated in the context of meeting specific ecological flows under different flow regimes and potentially assist with decisions regarding groundwater and surface

  8. Measurement of the lidar signal fluctuation with a shot-per-shot instrument.

    Science.gov (United States)

    Durieux, E; Fiorani, L

    1998-10-20

    A measurement of the signal noise was carried out with a shot-per-shot lidar. This system was operated in the UV spectral region for ozone profiling in the low troposphere. We report on important discrepancies between our results and the estimations based on the assumptions commonly supporting the numerical modeling of lidar experiments.

  9. Shot-to-shot comparison of the first Li-beam-driven hohlraum experiments

    International Nuclear Information System (INIS)

    Derzon, M.S.; Rochau, G.E.; Chandler, G.A.; Moats, A.R.; Leeper, R.J.

    1995-01-01

    Shot-to-shot comparison of the first Li-beam hohlraum experiments on PBFA II provides an opportunity to measure and determine the factor that affect the on-axis reproducibility of the Li-ion beam. Both inner-shell and thermal x-ray emission are used to estimate the relative beam power on target from shot to shot. The M- and L-shell Au x-ray yield measurements were made with an array of 11 filtered p-i-n detectors, and the thermal emission measurements were made with an array of three filtered bolometers. The analysis shows that the beam intensity on target varied by more than a factor of 10 during the shot series. By correlating the results of the beam on target with other diagnostics and events, we have identified some potential causes for these variations

  10. Pulsar radiation as polarized shot noise

    International Nuclear Information System (INIS)

    Cordes, J.M.

    1976-01-01

    Pulsar radiation can be resonably modeled as amplitude-modulated shot noise for which the amplitude modulations correspond to the subpulses and micropulses that comprise the structure of single pulses. The shot noise fluctuates on nanosecond time scales and therefore has a bandwidth typical of pulsars, namely, 1-10 GHz. If curvature radiation from bunches of coherently radiating particles is the relevant radiation mechanism, then the radiation from a single bunch corresponds to a shot pulse; such a physical interpretation is not crucial to the validity of the shot noise model, however. We calculate some statistics of the corresponding signal in a narrow-band receiver system, an informative one being the intensity modulation index of the narrow-band noise from which it can be determined whether or not the noise has Gaussian statistics. Departures from Gaussian statistics can occur if intensity variations are due primarily to changes in the number of particles radiating coherently at any instant. If the temporal density of shot pulses is sufficiently high, however, only Gaussian statistics will be observed, meaning that extensive incoherent addition occurs in the generation and the propagation of the radiation.The first and second moments of the Stokes parameters of narrow-band signals are derived for both time-independent and time-variable polarization. It is shown how the polarization properties of short time scale structure can be determined from the autocorrelation functions of the Stokes parameters

  11. Multiple echo multi-shot diffusion sequence.

    Science.gov (United States)

    Chabert, Steren; Galindo, César; Tejos, Cristian; Uribe, Sergio A

    2014-04-01

    To measure both transversal relaxation time (T2 ) and diffusion coefficients within a single scan using a multi-shot approach. Both measurements have drawn interest in many applications, especially in skeletal muscle studies, which have short T2 values. Multiple echo single-shot schemes have been proposed to obtain those variables simultaneously within a single scan, resulting in a reduction of the scanning time. However, one problem with those approaches is the associated long echo read-out. Consequently, the minimum achievable echo time tends to be long, limiting the application of these sequences to tissues with relatively long T2 . To address this problem, we propose to extend the multi-echo sequences using a multi-shot approach, so that to allow shorter echo times. A multi-shot dual-echo EPI sequence with diffusion gradients and echo navigators was modified to include independent diffusion gradients in any of the two echoes. The multi-shot approach allows us to drastically reduce echo times. Results showed a good agreement for the T2 and mean diffusivity measurements with gold standard sequences in phantoms and in vivo data of calf muscles from healthy volunteers. A fast and accurate method is proposed to measure T2 and diffusion coefficients simultaneously, tested in vitro and in healthy volunteers. Copyright © 2013 Wiley Periodicals, Inc.

  12. Demonstration of Shot-noise-limited Swept Source OCT Without Balanced Detection.

    Science.gov (United States)

    Fathipour, Vala; Schmoll, Tilman; Bonakdar, Alireza; Wheaton, Skylar; Mohseni, Hooman

    2017-04-26

    Optical coherence tomography (OCT) has been utilized in a rapidly growing number of clinical and scientific applications. In particular, swept source OCT (SS-OCT) has attracted many attentions due to its excellent performance. So far however, the limitations of existing photon detectors have prevented achieving shot-noise-limited sensitivity without using balanced-detection scheme in SS-OCT, even when superconducting single-photon detectors were used. Unfortunately, balanced-detection increases OCT system size and cost, as it requires many additional components to boost the laser power and maintain near ideal balanced performance across the whole optical bandwidth. Here we show for the first time that a photon detector is capable of achieving shot noise limited performance without using the balanced-detection technique in SS-OCT. We built a system using a so-called electron-injection photodetector, with a cutoff-wavelength of 1700 nm. Our system achieves a shot-noise-limited sensitivity of about -105 dB at a reference laser power of ~350 nW, which is more than 30 times lower laser power compared with the best-reported results. The high sensitivity of the electron-injection detector allows utilization of micron-scale tunable laser sources (e.g. VCSEL) and eliminates the need for fiber amplifiers and highly precise couplers, which are an essential part of the conventional SS-OCT systems.

  13. Lasers.

    Science.gov (United States)

    Passeron, T

    2012-12-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  14. [Lasers].

    Science.gov (United States)

    Passeron, T

    2012-11-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  15. SunShot Initiative Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    DOE Solar Energy Technologies Office

    2015-04-01

    The U.S. Department of Energy (DOE) SunShot Initiative is a collaborative national effort launched in 2011 that aggressively drives innovation to make solar energy fully cost competitive with traditional energy sources before the end of the decade. The SunShot fact sheet outlines goals and successes of the program as it works with private companies, universities, non-profit organizations, state and local governments, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour, without incentives, by the year 2020.

  16. Sport video shot segmentation and classification

    Science.gov (United States)

    Dahyot, Rozenn; Rea, Niall; Kokaram, Anil C.

    2003-06-01

    This paper considers the statistics of local appearance based measures that are suitable for the visual parsing of sport events. The moments of the colour information are computed, and the shape content in the frames is characterised by the moments of local shape measures. Their generation process is very low cost. The temporal evolution of the features then is modelled with a Hidden Markov Model. The HMM is used to generate higher level information by classifying the shots as close ups, court views, crowd shots and so on. The paper illustrates how those simple features, coupled with the HMM, can be used for parsing snooker and tennis footages.

  17. Tabletop single-shot extreme ultraviolet Fourier transform holography of an extended object.

    Science.gov (United States)

    Malm, Erik B; Monserud, Nils C; Brown, Christopher G; Wachulak, Przemyslaw W; Xu, Huiwen; Balakrishnan, Ganesh; Chao, Weilun; Anderson, Erik; Marconi, Mario C

    2013-04-22

    We demonstrate single and multi-shot Fourier transform holography with the use of a tabletop extreme ultraviolet laser. The reference wave was produced by a Fresnel zone plate with a central opening that allowed the incident beam to illuminate the sample directly. The high reference wave intensity allows for larger objects to be imaged compared to mask-based lensless Fourier transform holography techniques. We obtain a spatial resolution of 169 nm from a single laser pulse and a resolution of 128 nm from an accumulation of 20 laser pulses for an object ~11x11μm(2) in size. This experiment utilized a tabletop extreme ultraviolet laser that produces a highly coherent ~1.2 ns laser pulse at 46.9 nm wavelength.

  18. Potentiometric surfaces, summer 2013 and winter 2015, and select hydrographs for the Southern High Plains aquifer, Cannon Air Force Base, Curry County, New Mexico

    Science.gov (United States)

    Collison, Jake

    2016-04-07

    Cannon Air Force Base (Cannon AFB) is located in the High Plains physiographic region of east-central New Mexico, about 5 miles west of Clovis, New Mexico. The area surrounding Cannon AFB is primarily used for agriculture, including irrigated cropland and dairies. The Southern High Plains aquifer is the principal source of water for Cannon AFB, for the nearby town of Clovis, and for local agriculture and dairies. The Southern High Plains aquifer in the vicinity of Cannon AFB consists of three subsurface geological formations: the Chinle Formation of Triassic age, the Ogallala Formation of Tertiary age, and the Blackwater Draw Formation of Quaternary age. The Ogallala Formation is the main water-yielding formation of the Southern High Plains aquifer. Groundwater-supplied, center-pivot irrigation dominates pumping from the Southern High Plains aquifer in the area surrounding Cannon AFB, where the irrigation season typically extends from early March through October. The U.S. Geological Survey has been monitoring groundwater levels in the vicinity of Cannon AFB since 1954 and has developed general potentiometric-surface maps that show groundwater flow from northwest to southeast in the study area. While previous potentiometric-surface maps show the general direction of groundwater flow, a denser well network is needed to show details of groundwater flow at a local scale. Groundwater levels were measured in 93 wells during summer 2013 and 100 wells during winter 2015.The summer and winter potentiometric-surface maps display the presence of what is interpreted to be a groundwater trough trending from the northwest to the southeast through the study area. This groundwater trough may be the hydraulic expression of a Tertiary-age paleochannel. Groundwater north of the trough flows in a southerly direction into the trough, and groundwater south of the trough flows in an easterly direction into the trough.During the 18-month period between summer 2013 and winter 2015, changes

  19. Modelling single shot damage thresholds of multilayer optics for high-intensity short-wavelength radiation sources

    NARCIS (Netherlands)

    Loch, R.A.; Sobierajski, R.; Louis, Eric; Bosgra, J.; Bosgra, J.; Bijkerk, Frederik

    2012-01-01

    The single shot damage thresholds of multilayer optics for highintensity short-wavelength radiation sources are theoretically investigated, using a model developed on the basis of experimental data obtained at the FLASH and LCLS free electron lasers. We compare the radiation hardness of commonly

  20. Shot-to-shot intensity and wavefront stability of high-harmonic generation.

    Science.gov (United States)

    Künzel, S; Williams, G O; Boutu, W; Galtier, E; Barbrel, B; Lee, H J; Nagler, B; Zastrau, U; Dovillaire, G; Lee, R W; Merdji, H; Zeitoun, Ph; Fajardo, M

    2015-05-20

    We report on the shot-to-shot stability of intensity and spatial phase of high-harmonic generation (HHG). The intensity stability is measured for each high-harmonic (HH) order with a spectrometer. Additionally, the spatial phase is measured with an XUV wavefront sensor for a single HH order measured in a single shot, which according to our knowledge was not reported before with a Hartmann wavefront sensor. Furthermore, we compare the single-shot measurement of the spatial phase with time-integrated measurements and we show that the XUV wavefront sensor is a useful tool to simultaneously optimize the spatial phase and intensity of HHG within the available HHG parameter range used in this study.

  1. Effect of the peening intensity by shot peening

    International Nuclear Information System (INIS)

    Cheong, Seong Kyun; Chung, Suk Choo; Lee, Seung Ho

    2001-01-01

    The shot peening process is most often used to improve fatigue properties of metal parts. The single most critical parameter of the shot peening process is the shot ball itself. Without the correct quality media, all other shot peening parameters are extraneous and the desired fatigue improvement and consistency of improvement will not be achieved. shot peening involves modifications of the surface and subsurface condition of a material that can be described by the change of the residual stresses, the hardness, and the surface roughness. This paper presents the shot peening to optimize the shot ball parameters. The effect of shot peening parameter on the surface roughness, surface hardness and residual stress are investigated

  2. Shot-by-shot spectrum model for rod-pinch, pulsed radiography machines

    Directory of Open Access Journals (Sweden)

    Wm M. Wood

    2018-02-01

    Full Text Available A simplified model of bremsstrahlung production is developed for determining the x-ray spectrum output of a rod-pinch radiography machine, on a shot-by-shot basis, using the measured voltage, V(t, and current, I(t. The motivation for this model is the need for an agile means of providing shot-by-shot spectrum prediction, from a laptop or desktop computer, for quantitative radiographic analysis. Simplifying assumptions are discussed, and the model is applied to the Cygnus rod-pinch machine. Output is compared to wedge transmission data for a series of radiographs from shots with identical target objects. Resulting model enables variation of parameters in real time, thus allowing for rapid optimization of the model across many shots. “Goodness of fit” is compared with output from LSP Particle-In-Cell code, as well as the Monte Carlo Neutron Propagation with Xrays (“MCNPX” model codes, and is shown to provide an excellent predictive representation of the spectral output of the Cygnus machine. Improvements to the model, specifically for application to other geometries, are discussed.

  3. Shot-by-shot spectrum model for rod-pinch, pulsed radiography machines

    Science.gov (United States)

    Wood, Wm M.

    2018-02-01

    A simplified model of bremsstrahlung production is developed for determining the x-ray spectrum output of a rod-pinch radiography machine, on a shot-by-shot basis, using the measured voltage, V(t), and current, I(t). The motivation for this model is the need for an agile means of providing shot-by-shot spectrum prediction, from a laptop or desktop computer, for quantitative radiographic analysis. Simplifying assumptions are discussed, and the model is applied to the Cygnus rod-pinch machine. Output is compared to wedge transmission data for a series of radiographs from shots with identical target objects. Resulting model enables variation of parameters in real time, thus allowing for rapid optimization of the model across many shots. "Goodness of fit" is compared with output from LSP Particle-In-Cell code, as well as the Monte Carlo Neutron Propagation with Xrays ("MCNPX") model codes, and is shown to provide an excellent predictive representation of the spectral output of the Cygnus machine. Improvements to the model, specifically for application to other geometries, are discussed.

  4. Histopathology of mallards dosed with lead and selected substitute shot

    Science.gov (United States)

    Locke, L.N.; Irby, H.D.; Bagley, George E.

    1967-01-01

    The histopathological response of male game farm mallards fed lead, three types of plastic-coated lead, two lead-magnesium alloys, iron, copper, zinc-coated iron, and molybdenum-coated iron shot was studied. Mallards fed lead, plastic-coated lead, or lead-magnesium alloy shot developed a similar pathological response, including the formation of acid-fast intranuclear inclusion bodies in the kidneys. Birds fed iron or molybdenum-coated iron shot developed hemosiderosis of the liver. Two of four mallards fed zinc-coated iron shot also developed hemosiderosis of the liver. No lesions were found in mallards fed copper shot.

  5. NASTRAN multipartitioning and one-shot substructuring

    Science.gov (United States)

    Levy, A.

    1973-01-01

    For intermediate size problems where all the data is accessible, the present method of substructuring in three separate phases (for static analysis) is unneccessarily cumbersome. The versatility of NASTRAN's DMAP and internal logic lends itself to finding a practical alternative to these procedures whereby self-contained special-purpose ALTER packages can be written to be run in one pass. Two examples are presented here under the titles of multipartitioning and one-shot substructuring. The flow of multipartitioning resembles that of the present three-phase substructuring. The basic effect is to partition the structure into substructures and operate on each substructure separately. This can be used to reduce the bandwidth of a given problem as well as to store information which will allow a change to be made in one of the substructures in a later run. This latter procedure is carried out in a second program titled one-shot substructuring.

  6. The Slap Shot in Ice Hockey

    Science.gov (United States)

    Cross, Rod; Lindsey, Crawford

    2018-01-01

    An ice hockey player can strike a puck at speeds up to about 45 m/s (100 mph) using a technique known as the slap shot. There is nothing unusual about the speed, since golf balls, tennis balls, and baseballs can also be projected at that speed or even higher. The unusual part is that the player strikes the ice before striking the puck, causing the…

  7. SnapShot: GI tract development.

    Science.gov (United States)

    McGrath, Patrick S; Wells, James M

    2015-03-26

    The endoderm germ layer contributes to the respiratory and gastrointestinal (GI) lineages during development, giving rise to an array of specialized epithelial cell types lining organs, including the thyroid, thymus, lungs, liver, biliary system, pancreas, and intestines. This SnapShot timelines and summarizes key stages following gastrulation, including endoderm patterning, organ specification, and organogenesis. A lineage tree of the developing endocrine pancreas is outlined to further illustrate this process. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Centrifugal shot blasting. Innovative technology summary report

    International Nuclear Information System (INIS)

    1999-07-01

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer

  9. Beauty and science in a shot

    Science.gov (United States)

    Ciceri, Piera

    2017-04-01

    Taking pictures has become a daily action for young. Photography is an essential component of many areas of science, has played a crucial role in the study of anatomy, botany, archeology, ... Still today it is a "scientific tool" in the school textbooks: pictures describe, make reality larger or smaller, faster or slower, show evidence and experimental results. But a photograph has the ability to move, engage and inspire viewers. That means that a photograph can build an emotional bridge between science and people. People and students can get closer to science through beautiful, evocative and expressive shot. In this project students are involved in taking pictures with a scientific and aesthetic content looking around, setting an experiment, watching nature, playing with light, point of wiew, colors and perspective. They have to write a short text and a title that explains the scientific content, why and how they have taken the picture. Both description and title should let increase curiosity, could looks fun or stress artistic aspects. Student show their shots in an official public event in Milan managed by a committee of science and photograph experts and in a local event to parents and local community. "Shots of science" is a project promoted by the italian national association "Scienza under 18", the Physic Department of "Università degli Studi di Milano" and the "Museo di fotografia contemporanea" of Cinisello Balsamo (MI) that help students in discussing about scientific and artistic aspects of their shots. This project contributes to develop digital skills (such as to manage digital images, to share documents, to learn about copyright and creative commons license), communication skills (such as to write a caption, public speaking, to use a picture to communicate), collaboration skills (such as to work with pairs, to respect scheduled times, to be positive in giving and taking into account suggestions) and artistic skills (to learn how to compose a good

  10. A bootstrapped, low-noise, and high-gain photodetector for shot noise measurement

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Haijun; Yang, Wenhai; Li, Zhixiu; Li, Xuefeng; Zheng, Yaohui, E-mail: yhzheng@sxu.edu.cn [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China)

    2014-01-15

    We presented a low-noise, high-gain photodetector based on the bootstrap structure and the L-C (inductance and capacitance) combination. Electronic characteristics of the photodetector, including electronic noise, gain and frequency response, and dynamic range, were verified through a single-frequency Nd:YVO{sub 4} laser at 1064 nm with coherent output. The measured shot noise of 50 μW laser was 13 dB above the electronic noise at the analysis frequency of 2 MHz, and 10 dB at 3 MHz. And a maximum clearance of 28 dB at 2 MHz was achieved when 1.52 mW laser was illuminated. In addition, the photodetector showed excellent linearities for both DC and AC amplifications in the laser power range between 12.5 μW and 1.52 mW.

  11. Osseointegration improvement by shot peening in titanium dental implants

    International Nuclear Information System (INIS)

    Aparicio, C.; Gil, F.J.; Planell, J.A.; Padros, A.; Peraire, C.

    1998-01-01

    In order to optimize the implant-bone fixation, different shot peening treatments with different shot particles (TiO 2 , Al 2 O 3 ; SiC) have been made. The influence that each type of shot particle has in the bone colonization on the different treatment surfaces has been determined by means of osteoblast-like cells culture. Commercially pure titanium discs have been shot peened. Their qualitative and quantitative surface roughness have been characterized; as well as their surface contamination caused by the shot particles. Particle size has also been determined, before and after the treatment, in order to evaluate their breaking averages. Finally, a TiO 2 shot particles manufacture process by sintering has been developed. The manufacture has been necessary since this type of shot particles are not available in the market with the adequate size. (Author) 10 refs

  12. Surface severe plastic deformation of AISI 304 via conventional shot peening, severe shot peening and repeening

    Energy Technology Data Exchange (ETDEWEB)

    Unal, Okan, E-mail: unalokan78@gmail.com [Mechanical Engineering Department, Bartın University, Bartın 74100 (Turkey); Varol, Remzi [Mechanical Engineering Department, Suleyman Demirel University, Isparta 32200 (Turkey)

    2015-10-01

    Highlights: • CSP and SSP treatments transform austenite to metastable martensite structure. • Nanograin layer thickness after CSP and SSP is 8 μm and 22 μm, respectively. • Shot peening leads to carbon segregation from coarse to nano grain layer. • Repeening is an effective way to reduce surface roughness. - Abstract: Air blast conventional shot peening (CSP), severe shot peening (SSP) and repeening (RP) as a severe plastic deformation applications on AISI 304 austenitic stainless steel is addressed. Shot peened specimens are investigated based on optical, FESEM and digital microscope. The investigations present the austenite transformation to metastable martensite via mechanical twinning due to plastic deformation with high strain rates. It is found that SSP induces thicker nanograin layer with compared to CSP. In XRD studies, the austenite peaks broaden by means of severe shot peening and FWHM increase reveals the grain size reduction below 25 nm regimes on the surface. In EDAX line analysis of CSP specimen, carbon content increase has been detected from deformed layer through the nanocrystalline layer then the content reduces. The carbon segregation takes place due to the energy level distinction between dislocations and Fe−C bonds. 3d contour digital microscope studies and roughness investigations reveal that SSP has deleterious side effect on the surface roughness and surface flatness. However, RP is an effective way to reduce the surface roughness to reasonable values.

  13. Reliability analysis of minimum energy on target for laser facilities with more beam lines

    International Nuclear Information System (INIS)

    Chen Guangyu

    2008-01-01

    Shot reliability performance measures of laser facilities with more beam lines pertain to three categories: minimum-energy-on-target, power balance, and shot diagnostics. Accounting for symmetry of NIF beam line design and similarity of subset reliability in a same partition, a fault tree of meeting minimum-energy-on-target for the large laser facility shot of type K and a simplified method are presented, which are used to analyze hypothetic reliability of partition subsets in order to get trends of influences increasing number of beam lines and diverse shot types of large laser facilities on their shot reliability. Finally, it finds that improving component reliability is more crucial for laser facilities with more beam lines in comparison with those with beam lines and functional diversity from design flexibility is greatly helpful for improving shot reliability. (authors)

  14. Single shot diffraction of picosecond 8.7-keV x-ray pulses

    Directory of Open Access Journals (Sweden)

    F. H. O’Shea

    2012-02-01

    Full Text Available We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO_{2} laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO_{2} laser yielded 6×10^{7} x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to a flat silicon (111 crystal. 10^{2} diffracted photons were detected. The spectrum of the detected x rays is compared to simulation. The diffraction and detection of 10^{2} x rays is a key step to a more efficient time resolved diagnostic in which the number of observed x rays might reach 10^{4}; enabling a unique, flexible x-ray source as a sub-ps resolution diagnostic for studying the evolution of chemical reactions, lattice deformation and melting, and magnetism.

  15. Shot-to-shot fluctuations in the directed superradiant emission from extended atomic samples

    International Nuclear Information System (INIS)

    Clemens, J P; Horvath, L; Sanders, B C; Carmichael, H J

    2004-01-01

    We study collective spontaneous emission from arbitrary distributions of N two-state atoms using quantum trajectory theory and without an a priori single-mode assumption. Assuming a fully excited initial state, we calculate the angular distribution of the average intensity, focusing on pencil- and disc-shaped samples. The formalism is developed around an unravelling of the master equation in terms of source mode quantum jumps. A modified boson approximation is made to treat the many-atom case, where it is found that strong directional superradiance with shot-to-shot fluctuations occurs for a few hundred to a few thousand atoms

  16. Infrared single shot diagnostics for the longitudinal profile of the electron bunches at FLASH

    International Nuclear Information System (INIS)

    Delsim-Hashemi, Hossein

    2008-09-01

    The longitudinal profile of electron bunches plays an important role in the design of single-pass free electron lasers and future linear e + e - colliders. For the free electron laser FLASH in Hamburg, a longitudinal compression scheme is used which results in an asymmetric longitudinal bunch profile with a 'spike'. This 'spike', which has a very high peak current, is used in a high-gain SASE-FEL process to produce high intensity (about 70 μJ) femtosecond photon pulses in the XUV wavelength range. The required high peak current of the electron bunch is realized by confining a large number of electrons in a width, measured in time units, of few tens of femtosecond, making the diagnostics of such bunches a challenge. Furthermore, the operation of facilities such as FLASH shows that single-shot diagnostics is indispensable. It is intuitive to use a time domain method to measure the electron bunch length. However, when the structures present in the bunch profile fall in the femtoseconds range, this is beyond the resolution of time-resolved methods developed so far. In this thesis, a wavelength-domain technique is described that can fulfill both requirements of single shot and high resolution reaching to the femtoseconds range. The amount of charge that is confined in a typical length of several femtoseconds (FWHM of the spike) can be determined by a novel single-shot spectrometer that resolves the coherent radiation (e.g. coherent transition radiation) in the far-infrared and mid-infrared range. Furthermore the extension of this single-shot spectroscopy to shorter wavelengths reaching the near-infrared, makes it possible to investigate the presence of structures in the bunch profile that might correlate or anti-correlate to the SASE intensity. (orig.)

  17. Infrared single shot diagnostics for the longitudinal profile of the electron bunches at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Delsim-Hashemi, Hossein

    2008-09-15

    The longitudinal profile of electron bunches plays an important role in the design of single-pass free electron lasers and future linear e{sup +}e{sup -} colliders. For the free electron laser FLASH in Hamburg, a longitudinal compression scheme is used which results in an asymmetric longitudinal bunch profile with a 'spike'. This 'spike', which has a very high peak current, is used in a high-gain SASE-FEL process to produce high intensity (about 70 {mu}J) femtosecond photon pulses in the XUV wavelength range. The required high peak current of the electron bunch is realized by confining a large number of electrons in a width, measured in time units, of few tens of femtosecond, making the diagnostics of such bunches a challenge. Furthermore, the operation of facilities such as FLASH shows that single-shot diagnostics is indispensable. It is intuitive to use a time domain method to measure the electron bunch length. However, when the structures present in the bunch profile fall in the femtoseconds range, this is beyond the resolution of time-resolved methods developed so far. In this thesis, a wavelength-domain technique is described that can fulfill both requirements of single shot and high resolution reaching to the femtoseconds range. The amount of charge that is confined in a typical length of several femtoseconds (FWHM of the spike) can be determined by a novel single-shot spectrometer that resolves the coherent radiation (e.g. coherent transition radiation) in the far-infrared and mid-infrared range. Furthermore the extension of this single-shot spectroscopy to shorter wavelengths reaching the near-infrared, makes it possible to investigate the presence of structures in the bunch profile that might correlate or anti-correlate to the SASE intensity. (orig.)

  18. Digital Holography at Shot Noise Level

    OpenAIRE

    Verpillat, Frédéric; Joud, Fadwa; Atlan, Michael; Gross, Michel

    2012-01-01

    International audience; By a proper arrangement of a digital holography setup, that combines off-axis geometry with phase-shifting recording conditions, it is possible to reach the theoretical shot noise limit, in real-time experiments.We studied this limit, and we show that it corresponds to 1 photo-electron per pixel within the whole frame sequence that is used to reconstruct the holographic image. We also show that Monte Carlo noise synthesis onto holograms measured at high illumination le...

  19. Shuttlecock Velocity of a Badminton Drop Shot

    Directory of Open Access Journals (Sweden)

    Ampharin Ongvises

    2013-12-01

    Full Text Available In a badminton ‘drop shot’, the shuttlecock is struck by a non-rotating racquet at low speed. In this investigation, a shuttlecock was hit by a badminton racquet in a linear collision, simulating a drop shot. The collision was recorded with high-speed video and the velocities of the racquet and shuttlecock determined. The relationship between the impact velocity of the racquet and the velocity of the shuttlecock as it leaves the badminton racquet after collision was found to be proportional over the range tested.

  20. SnapShot: Phosphoregulation of Mitosis.

    Science.gov (United States)

    Burgess, Andrew; Vuong, Jenny; Rogers, Samuel; Malumbres, Marcos; O'Donoghue, Seán I

    2017-06-15

    During mitosis, a cell divides its duplicated genome into two identical daughter cells. This process must occur without errors to prevent proliferative diseases (e.g., cancer). A key mechanism controlling mitosis is the precise timing of more than 32,000 phosphorylation and dephosphorylation events by a network of kinases and counterbalancing phosphatases. The identity, magnitude, and temporal regulation of these events have emerged recently, largely from advances in mass spectrometry. Here, we show phosphoevents currently believed to be key regulators of mitosis. For an animated version of this SnapShot, please see http://www.cell.com/cell/enhanced/odonoghue2. Copyright © 2017. Published by Elsevier Inc.

  1. Concrete Cleaning, Inc. centrifugal shot blaster: Baseline report; Summary

    International Nuclear Information System (INIS)

    1997-01-01

    The centrifugal shot blaster is an electronically operated shot-blast machine that removes layer of concrete of varying depths. Hardened steel shot propelled at a high rate of speed abrades the surface of the concrete. The depth of material removed is determined by the rate of speed the machine is traveling and the volume of shot being fired into the blast chamber. The steel shot is reused until it is pulverized to dust, which is deposited in the waste container with the concrete being removed. Debris is continually vacuumed by a large dust collection system attached to the shot blaster. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust

  2. Catastrophe insurance modeled by shot-noise processes

    OpenAIRE

    Schmidt, Thorsten

    2014-01-01

    Shot-noise processes generalize compound Poisson processes in the following way: a jump (the shot) is followed by a decline (noise). This constitutes a useful model for insurance claims in many circumstances; claims due to natural disasters or self-exciting processes exhibit similar features. We give a general account of shot-noise processes with time-inhomogeneous drivers inspired by recent results in credit risk. Moreover, we derive a number of useful results for modeling and pricing with s...

  3. Biomechanical Analysis of the Jump Shot in Basketball

    OpenAIRE

    Struzik Artur; Pietraszewski Bogdan; Zawadzki Jerzy

    2014-01-01

    Basketball players usually score points during the game using the jump shot. For this reason, the jump shot is considered to be the most important element of technique in basketball and requires a high level of performance. The aim of this study was to compare the biomechanical characteristics of the lower limbs during a jump shot without the ball and a countermovement jump without an arm swing. The differences between variables provide information about the potential that an athlete can util...

  4. Shot Noise Thermometry for Thermal Characterization of Templated Carbon Nanotubes

    OpenAIRE

    Sayer, Robert A; Kim, Sunkook; Franklin, Aaron D; Mohammadi, Saeed; Fisher, Timothy

    2010-01-01

    A carbon nanotube (CNT) thermometer that operates on the principles of electrical shot noise is reported. Shot noise thermometry is a self-calibrating measurement technique that relates statistical fluctuations in dc current across a device to temperature. A structure consisting of vertical, top, and bottom-contacted single-walled carbon nanotubes in a porous anodic alumina template was fabricated and used to measure shot noise. Frequencies between 60 and 100 kHz were observed to preclude sig...

  5. Methodology of Testing Shot Blasting Machines in Industrial Conditions

    Directory of Open Access Journals (Sweden)

    R. Wrona

    2012-04-01

    Full Text Available Shot blasting machines are widely used for automated surface treatment and finishing of castings. In shot blasting processes the stream of shots is generated and shaped by blasting turbines, making up a kinetic and dynamic system comprising a separating rotor, an adapting sleeve and a propelling rotor provided with blades. The shot blasting performance- i.e. the quality of shot treated surfaces depends on the actual design and operational parameters of the unit whilst the values of relevant parameters are associated with the geometry of turbine components and the level of its integration with the separator system. The circulation of the blasting medium becomes the integrating factor of the process line, starting from the hopper, through the propeller turbine, casting treatment, separation of contaminated abrasive mixture, to its recycling and reuse.Inferior quality of the abrasive agent (shot and insufficient purity of the abrasive mixture are responsible for low effectiveness of shot blasting. However, most practitioners fail to fully recognise the importance of proper diagnostics of the shot blasting process in industrial conditions. The wearing of major machine components and of the blasting agent and quality of shot treated surfaces are often misinterpreted, hence the need to take into account all factors involved in the process within the frame of a comprehensive methodology.This paper is an attempt to formulate and apply the available testing methods to the engineering practice in industrial conditions.

  6. Entrance, exit, and reentrance of one shot with a shotgun

    DEFF Research Database (Denmark)

    Gulmann, C; Hougen, H P

    1999-01-01

    The case being reported is one of a homicidal shotgun fatality with an unusual wound pattern. A 34-year-old man was shot at close range with a 12-gauge shotgun armed with No. 5 birdshot ammunition. The shot entered the left axillary region, exited through the left infraclavicular region, and ther......The case being reported is one of a homicidal shotgun fatality with an unusual wound pattern. A 34-year-old man was shot at close range with a 12-gauge shotgun armed with No. 5 birdshot ammunition. The shot entered the left axillary region, exited through the left infraclavicular region...

  7. Buildings vs. ballistics: Quantifying the vulnerability of buildings to volcanic ballistic impacts using field studies and pneumatic cannon experiments

    Science.gov (United States)

    Williams, G. T.; Kennedy, B. M.; Wilson, T. M.; Fitzgerald, R. H.; Tsunematsu, K.; Teissier, A.

    2017-09-01

    Recent casualties in volcanic eruptions due to trauma from blocks and bombs necessitate more rigorous, ballistic specific risk assessment. Quantitative assessments are limited by a lack of experimental and field data on the vulnerability of buildings to ballistic hazards. An improved, quantitative understanding of building vulnerability to ballistic impacts is required for informing appropriate life safety actions and other risk reduction strategies. We assessed ballistic impacts to buildings from eruptions at Usu Volcano and Mt. Ontake in Japan and compiled available impact data from eruptions elsewhere to identify common damage patterns from ballistic impacts to buildings. We additionally completed a series of cannon experiments which simulate ballistic block impacts to building claddings to investigate their performance over a range of ballistic projectile velocities, masses and energies. Our experiments provide new insights by quantifying (1) the hazard associated with post-impact shrapnel from building and rock fragments; (2) the effect of impact obliquity on damage; and (3) the additional impact resistance buildings possess when claddings are struck in areas directly supported by framing components. This was not well identified in previous work which may have underestimated building vulnerability to ballistic hazards. To improve assessment of building vulnerability to ballistics, we use our experimental and field data to develop quantitative vulnerability models known as fragility functions. Our fragility functions and field studies show that although unreinforced buildings are highly vulnerable to large ballistics (> 20 cm diameter), they can still provide shelter, preventing death during eruptions.

  8. Picosecond laser filamentation in air

    Science.gov (United States)

    2016-09-02

    under the terms of the Creative CommonsAttribution 3.0 licence . Any further distribution of this workmustmaintain attribution to the author(s) and the...at the wavelength of 1.053 μm, in a 90 mmdiameter beam. The laser operates in the single-shot regime (one shot in ten minutes). Laser pulses can be...The operator T̂ accounts for the self-steepening and space– time focusing effects [34]. Linear dispersion of air is included in equation (5) via the

  9. Collider shot setup for Run 2 observations and suggestions

    International Nuclear Information System (INIS)

    Annala, J.; Joshel, B.

    1996-01-01

    This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This is the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb -1 /week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb -1 for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent 'components': procedures, hardware, controls, and sociology. These components don't directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components

  10. Reactive pulsed laser deposition with gas jet

    International Nuclear Information System (INIS)

    Rakowski, R.; Bartnik, A.; Fiedorowicz, H.; Jarocki, R.; Kostecki, J.; Szczurek, M.

    2001-01-01

    Different metal (Sn, Al, steel, Cu, W) thin films were synthesized by reactive pulsed laser deposition on steel, copper and glass wafers. In our work pulsed Nd:glass (10 J, 800μs) laser system was used. Jet of gas was created by electromagnetic valve perpendicularly to the laser beam. Nitrogen, oxygen and argon were used. We used several to tens laser shots to obtain visible with the naked eye layers. Thin layers were observed under an optical microscope. (author)

  11. Coherent Polariton Laser

    Science.gov (United States)

    Kim, Seonghoon; Zhang, Bo; Wang, Zhaorong; Fischer, Julian; Brodbeck, Sebastian; Kamp, Martin; Schneider, Christian; Höfling, Sven; Deng, Hui

    2016-01-01

    The semiconductor polariton laser promises a new source of coherent light, which, compared to conventional semiconductor photon lasers, has input-energy threshold orders of magnitude lower. However, intensity stability, a defining feature of a coherent state, has remained poor. Intensity noise many times the shot noise of a coherent state has persisted, attributed to multiple mechanisms that are difficult to separate in conventional polariton systems. The large intensity noise, in turn, limits the phase coherence. Thus, the capability of the polariton laser as a source of coherence light is limited. Here, we demonstrate a polariton laser with shot-noise-limited intensity stability, as expected from a fully coherent state. This stability is achieved by using an optical cavity with high mode selectivity to enforce single-mode lasing, suppress condensate depletion, and establish gain saturation. Moreover, the absence of spurious intensity fluctuations enables the measurement of a transition from exponential to Gaussian decay of the phase coherence of the polariton laser. It suggests large self-interaction energies in the polariton condensate, exceeding the laser bandwidth. Such strong interactions are unique to matter-wave lasers and important for nonlinear polariton devices. The results will guide future development of polariton lasers and nonlinear polariton devices.

  12. Coherent Polariton Laser

    Directory of Open Access Journals (Sweden)

    Seonghoon Kim

    2016-03-01

    Full Text Available The semiconductor polariton laser promises a new source of coherent light, which, compared to conventional semiconductor photon lasers, has input-energy threshold orders of magnitude lower. However, intensity stability, a defining feature of a coherent state, has remained poor. Intensity noise many times the shot noise of a coherent state has persisted, attributed to multiple mechanisms that are difficult to separate in conventional polariton systems. The large intensity noise, in turn, limits the phase coherence. Thus, the capability of the polariton laser as a source of coherence light is limited. Here, we demonstrate a polariton laser with shot-noise-limited intensity stability, as expected from a fully coherent state. This stability is achieved by using an optical cavity with high mode selectivity to enforce single-mode lasing, suppress condensate depletion, and establish gain saturation. Moreover, the absence of spurious intensity fluctuations enables the measurement of a transition from exponential to Gaussian decay of the phase coherence of the polariton laser. It suggests large self-interaction energies in the polariton condensate, exceeding the laser bandwidth. Such strong interactions are unique to matter-wave lasers and important for nonlinear polariton devices. The results will guide future development of polariton lasers and nonlinear polariton devices.

  13. Reduction of shot noise in an interference gravitational-wave detector

    International Nuclear Information System (INIS)

    Troitskii, Yu V

    2001-01-01

    The characteristics of a Michelson interferometer whose arms are formed by reflection Fabri - Perot interferometers (FPIs), which is designed for measurements of ultra-small displacements, are studied. It is shown that the recent advances in the mirror coating technology along with the optimisation of the parameters of the FPI mirrors makes it possible to greatly improve the ratio of the signal to the shot noise. Optimal transmission of the front FPI mirror is approximately equal to the absorption coefficient of the mirrors. (laser applications and other topics in quantum electronics)

  14. Why Some Pool Shots are More Difficult Than Others

    Indian Academy of Sciences (India)

    IAS Admin

    The physics behind the game of billiards is rather well understood as is our grasp of classical me- chanics. We present here a mathematical expla- nation of why slice shots are more difficult than direct shots. Despite a large number of treatises dedicated to the study of physics of billiards, it appears that the simple ...

  15. Single-shot fluctuations in waveguided high-harmonic generation

    NARCIS (Netherlands)

    Goh, S.J.; Tao, Y.; van der Slot, Petrus J.M.; Bastiaens, Hubertus M.J.; Herek, Jennifer Lynn; Biedron, S.G.; Danailov, M.B.; Milton, S.V.; Boller, Klaus J.

    2015-01-01

    For exploring the application potential of coherent soft x-ray (SXR) and extreme ultraviolet radiation (XUV) provided by high-harmonic generation, it is important to characterize the central output parameters. Of specific importance are pulse-to-pulse (shot-to-shot) fluctuations of the high-harmonic

  16. Bond strength investigation of two shot moulded polymer

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul

    This report on the project “Bond strength investigation of two shot moulded polymers” has been submitted for fulfilling the requirements for the course “Experimental Plastic Technology – 42234” at IPL-DTU. Two shot moulding is a classic manufacturing process to combine two different polymers...

  17. Equilibrium and shot noise in mesoscopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Martin, T.

    1994-10-01

    Within the last decade, there has been a resurgence of interest in the study of noise in Mesoscopic devices, both experimentally and theoretically. Noise in solid state devices can have different origins: there is 1/f noise, which is believed to arise from fluctuations in the resistance of the sample due to the motion of impurities. On top of this contribution is a frequency independent component associated with the stochastic nature of electron transport, which will be the focus of this paper. If the sample considered is small enough that dephasing and inelastic effects can be neglected, equilibrium (thermal) and excess noise can be completely described in terms of the elastic scattering properties of the sample. As mentioned above, noise arises as a consequence of random processes governing the transport of electrons. Here, there are two sources of randomness: first, electrons incident on the sample occupy a given energy state with a probability given by the Fermi-Dirac distribution function. Secondly, electrons can be transmitted across the sample or reflected in the same reservoir where they came from with a probability given by the quantum mechanical transmission/reflection coefficients. Equilibrium noise refers to the case where no bias voltage is applied between the leads connected to the sample, where thermal agitation alone allows the electrons close to the Fermi level to tunnel through the sample. In general, equilibrium noise is related to the conductance of the sample via the Johnson-Nyquist formula. In the presence of a bias, in the classical regime, one expects to recover the full shot noise < {Delta}{sup 2}I >= 2I{Delta}{mu} as was observed a long time ago in vacuum diodes. In the Mesoscopic regime, however, excess noise is reduced below the shot noise level. The author introduces a more intuitive picture, where the current passing through the device is a superposition of pulses, or electron wave packets, which can be transmitted or reflected.

  18. A shot parameter specification subsystem for automated control of PBFA II accelerator shots

    International Nuclear Information System (INIS)

    Spiller, J.L.

    1987-01-01

    The author reports on the shot parameter specification subsystem (SPSS), an integral part of the automatic control system developed for the Particle Beam Fusion Accelerator II (PBFA II). This system has been designed to fully utilize the accelerator by tailoring shot parameters to the needs of the experimenters. The SPSS is the key to this flexibility. Automatic systems will be required on many pulsed power machines for the fastest turnaround, the highest reliability, and most cost effective operation. These systems will require the flexibility and the ease of use that is part of the SPSS. The author discusses how the PBFA II control system has proved to be an effective modular system, flexible enough to meet the demands of both the fast track construction of PBFA II and the control needs of Hermes III. This system is expected to meet the demands of most future machine changes

  19. Catastrophe Insurance Modeled by Shot-Noise Processes

    Directory of Open Access Journals (Sweden)

    Thorsten Schmidt

    2014-02-01

    Full Text Available Shot-noise processes generalize compound Poisson processes in the following way: a jump (the shot is followed by a decline (noise. This constitutes a useful model for insurance claims in many circumstances; claims due to natural disasters or self-exciting processes exhibit similar features. We give a general account of shot-noise processes with time-inhomogeneous drivers inspired by recent results in credit risk. Moreover, we derive a number of useful results for modeling and pricing with shot-noise processes. Besides this, we obtain some highly tractable examples and constitute a useful modeling tool for dynamic claims processes. The results can in particular be used for pricing Catastrophe Bonds (CAT bonds, a traded risk-linked security. Additionally, current results regarding the estimation of shot-noise processes are reviewed.

  20. Seasonal ingestion of toxic and nontoxic shot by Canada geese

    Science.gov (United States)

    DeStefano, S.; Brand, C.J.; Samuel, M.D.

    1995-01-01

    We used rates of ingested shot and elevated blood-lead levels (≥0.18 ppm) to estimate the proportion of Canada geese (Branta canadensis) exposed to lead on 3 study areas in Manitoba, Minnesota, and Missouri. Lead exposure was prevalent on all areas and was common after the hunting season closed, when up to 15% of geese could have been exposed to lead shot. However, the proportion of steel shot ingested by geese has increased during the past 2 decades. We suggest that lead exposure is still a source of indirect hunting mortality in Canada geese but project that the prevalence of lead exposure in the Eastern Prairie Population and other waterfowl populations will decrease as nontoxic shot regulations persist and hunters use steel or other nontoxic shot.

  1. Investigation of kinematics of knuckling shot in soccer

    Science.gov (United States)

    Asai, T.; Hong, S.

    2017-02-01

    In this study, we use four high-speed video cameras to investigate the swing characteristics of the kicking leg while delivering the knuckling shot in soccer. We attempt to elucidate the impact process of the kicking foot at the instant of its impact with the ball and the technical mechanisms of the knuckling shot via comparison of its curved motion with that of the straight and curved shots. Two high-speed cameras (Fastcam, Photron Inc., Tokyo, Japan; 1000 fps, 1024 × 1024 pixels) are set up 2 m away from the site of impact with a line of sight perpendicular to the kicking-leg side. In addition, two semi-high-speed cameras (EX-F1, Casio Computer Co., Ltd., Tokyo, Japan; 300 fps; 720 × 480 pixels) are positioned, one at the rear and the other on the kicking-leg side, to capture the kicking motion. We observe that the ankle joint at impact in the knuckling shot flexes in an approximate L-shape in a manner similar to the joint flexing for the curve shot. The hip's external rotation torque in the knuckling shot is greater than those of other shots, which suggests the tendency of the kicker to push the heel forward and impact with the inside of the foot. The angle of attack in the knuckling shot is smaller than that in other shots, and we speculate that this small attack angle is a factor in soccer kicks which generate shots with smaller rotational frequencies of the ball.

  2. Laser damage investigations of Cu mirrors

    International Nuclear Information System (INIS)

    Gorshkov, A.; Bel'bas, I.; Maslov, M.; Sannikov, V.; Vukolov, K.

    2005-01-01

    Laser tests were performed on Cu mirrors as 'first mirror' prototypes for laser diagnostics. Data on laser damage thresholds of surfaces under the influence of pulsed YAG laser radiation were obtained for single shot and after about 1.5 x 10 5 shots. The experiments were carried out using three types of copper mirrors: diamond-turned mirror, diamond-turned substrate with copper coating and reflection grating on a copper coated mirror. The lifetime of the copper mirrors was tested. Diffusion scattering was used as a monitor of mirror surface quality. The degradation of diamond turned copper mirrors in multiple pulse laser irradiation appears to be in satisfactory accordance with a model for multipulse laser damage of metal mirrors up to 1.5 x 10 5 laser pulses. The degradation of copper coated mirrors has a more complicated behaviour

  3. Ultrashort laser pulse driven inverse free electron laser accelerator experiment

    Directory of Open Access Journals (Sweden)

    J. T. Moody

    2016-02-01

    Full Text Available In this paper we discuss the ultrashort pulse high gradient inverse free electron laser accelerator experiment carried out at the Lawrence Livermore National Laboratory which demonstrated gradients exceeding 200  MV/m using a 4 TW 100 fs long 800 nm Ti:Sa laser pulse. Due to the short laser and electron pulse lengths, synchronization was determined to be one of the main challenges in this experiment. This made necessary the implementation of a single-shot, nondestructive, electro-optic sampling based diagnostics to enable time-stamping of each laser accelerator shot with <100  fs accuracy. The results of this experiment are expected to pave the way towards the development of future GeV-class IFEL accelerators.

  4. Increased distance of shooting on basketball jump shot.

    Science.gov (United States)

    Okazaki, Victor Hugo Alves; Rodacki, André Luiz Félix

    2012-01-01

    The present study analyzed the effect of increased distance on basketball jump shot outcome and performance. Ten male expert basketball players were filmed and a number of kinematic variables analyzed during jump shot that were performed from three conditions to represent close, intermediate and far distances (2.8, 4.6, and 6.4m, respectively). Shot accuracy decreased from 59% (close) to 37% (far), in function of the task constraints (p shot was performed from close (78.92°) in comparison to intermediate distances (65.60°). While, ball release velocity increased (p jump shot accuracy when distance is augmented. Key pointsThe increased distance leads to greater spatial con-straint over shot movement that demands an adapta-tion of the movement for the regulation of the accu-racy and the impulse generation to release the ball.The reduction in balls release height and release angle, in addition to the increase in balls release ve-locity, were suggested as the main factors that de-creased shot accuracy with the distance increased.Players should look for release angles of shooting that provide an optimal balls release velocity to im-prove accuracy.

  5. Single-shot beam profile diagnostics for x-ray FEL's using gas fluorescence

    Science.gov (United States)

    Feng, Yiping; Zhu, Diling; Weninger, Clemens; Alonso-Mori, Roberto; Chollet, Matthieu; Damiani, Daniel S.; Glownia, James M.; Hastings, Jerome B.; Nelson, Silke; Song, Sanghoon; Robert, Aymeric

    2017-06-01

    We report experimental demonstration of capturing single-shot X-ray Free-electron Laser (FEL) beam profiles using gas fluorescence. The measurement was carried out at the Linac Coherent Light Source using 7 keV hard X-rays propagating through ambient air. The nitrogen fluorescence emitted upon the passage of the X-ray FEL beam were imaged using a highly sensitive optical setup, and there was sufficient optical yield that single-shot measurements were feasible. By taking two orthogonal and simultaneous images, the beam trajectory could be determined in a nearly non-invasive manner, and is best suited for photon energies in the soft X-ray regime, where such a diagnostic capability has been largely unavailable previously. The integrated intensity of the images could also serve as a non-invasive intensity monitor, complementary to current implementations of gas- and solidbased monitors. High repetition-rate Free-electron Lasers can greatly benefit from such a new diagnostic tool for eliminating potential thermal damages.

  6. Increased Distance of Shooting on Basketball Jump Shot

    OpenAIRE

    Okazaki, Victor Hugo Alves; Rodacki, André Luiz Félix

    2012-01-01

    The present study analyzed the effect of increased distance on basketball jump shot outcome and performance. Ten male expert basketball players were filmed and a number of kinematic variables analyzed during jump shot that were performed from three conditions to represent close, intermediate and far distances (2.8, 4.6, and 6.4m, respectively). Shot accuracy decreased from 59% (close) to 37% (far), in function of the task constraints (p < 0.05). Ball release height decreased (p < 0.05) from 2...

  7. Single shot, double differential spectral measurements of inverse Compton scattering in the nonlinear regime

    Directory of Open Access Journals (Sweden)

    Y. Sakai

    2017-06-01

    Full Text Available Inverse Compton scattering (ICS is a unique mechanism for producing fast pulses—picosecond and below—of bright photons, ranging from x to γ rays. These nominally narrow spectral bandwidth electromagnetic radiation pulses are efficiently produced in the interaction between intense, well-focused electron and laser beams. The spectral characteristics of such sources are affected by many experimental parameters, with intense laser effects often dominant. A laser field capable of inducing relativistic oscillatory motion may give rise to harmonic generation and, importantly for the present work, nonlinear redshifting, both of which dilute the spectral brightness of the radiation. As the applications enabled by this source often depend sensitively on its spectra, it is critical to resolve the details of the wavelength and angular distribution obtained from ICS collisions. With this motivation, we present an experimental study that greatly improves on previous spectral measurement methods based on x-ray K-edge filters, by implementing a multilayer bent-crystal x-ray spectrometer. In tandem with a collimating slit, this method reveals a projection of the double differential angular-wavelength spectrum of the ICS radiation in a single shot. The measurements enabled by this diagnostic illustrate the combined off-axis and nonlinear-field-induced redshifting in the ICS emission process. The spectra obtained illustrate in detail the strength of the normalized laser vector potential, and provide a nondestructive measure of the temporal and spatial electron-laser beam overlap.

  8. One shot, one kill: the forces delivered by archer fish shots to distant targets.

    Science.gov (United States)

    Burnette, Morgan F; Ashley-Ross, Miriam A

    2015-10-01

    Archer fishes are skillful hunters of terrestrial prey, firing jets of water that dislodge insects perched on overhead vegetation. In the current investigation, we sought an answer to the question: are distant targets impractical foraging choices? Targets far from the shooter might not be hit with sufficient force to cause them to fall. However, observations from other investigators show that archer fish fire streams of water that travel in a non-ballistic fashion, which is thought to keep on-target forces high, even to targets that are several body lengths distant from the fish. We presented targets at different distances and investigated three aspects of foraging behavior: (i) on-target forces, (ii) shot velocity, (iii) a two-target choice assay to determine if fish would show any preference for downing closer targets or more distant targets. In general, shots from our fish (Toxotes chatareus) showed a mild decrease (less than 15% on average) in on-target forces at our most distant target offered (5.8 body lengths) with respect to the closest target offered (2.3 body lengths). One individual in our investigation showed slightly, but significantly, greater on-target forces as target distance increased. Forces on the furthest targets offered were found to double that of attachment forces for 200mg insects, even for individuals whose on-target forces showed mild decreases with increases in target distance. High-speed video analysis of jet impact with the target revealed that the shot was traveling in a non-ballistic manner, even to our most distant target offered, corroborating previous suppositions that on-target forces should remain high. Fish were able to accomplish this without large changes to shot velocity, but we did find evidence that the water jets appeared to differ in the timing of their acceleration as target distance increased. Our two-target choice experiment revealed that fish show preference for downing the closer target first, even though impact

  9. Preventive effect of shot peening on stress corrosion cracking

    International Nuclear Information System (INIS)

    Okido, Shinobu; Yoshimura, Toshihiko; Enomoto, Kunio; Saito, Hideyo; Morinaka, Ren; Ishikawa, Tetsuya

    2002-01-01

    The effect of shot peening (SP) on stress corrosion cracking (SCC) prevention was evaluated from the viewpoints of crack initiation and propagation. It was found that the residual stress in a Type-304 stainless-steel specimen is changed - from tensile of 300 MPa to compressive of -800 MPa - by shot peening, and the effective SP depth is 0.35 mm. It was also found that the crack initiation and propagation were prevented by shot peening. The mechanism by which the shot peening prevents these phenomena is explained according to the theory of superposition and loading history. That is, the prevention of crack initiation and propagation results from the fact that the compressive residual stress caused by SP decreases the applied load on the crack surface and prevents rupturing of the oxide film on the surface. Moreover, the effects of SCC prevention were shown to be valid when cyclic loading is applied after peening. (author)

  10. Experimental results on recent applications of shot peening

    International Nuclear Information System (INIS)

    Zaid, A.I.O.

    2001-01-01

    Shot peening is a mechanical surface treatment by which the surface of an elastic plastic component is subjected to multiple impact of high speed hard spheres, hence introducing a compressive stress layer of certain depth below the surface. This compressive stress layer results in enhancement of the fatigue life of the component. In this paper, the mechanism of shot peening and the effect of the parameters related to it are reviewed and discussed. The effect of shot peening on the fatigue life of aluminum alloy 7075-T6 and the phenomenological aspects associated with it are also given and discussed. Also, the effect of shot peening on aluminum alloy 2024-T3 in the as received and peened conditions is presented and discussed. Butt single U and butt double vee joints were both investigated from which it was found that the butt single U joint possessed higher values of fatigue life than the double vee joint for the same shot peening intensity. Finally, experimental results on a recent application that is the effect of shot peening on the fatigue life of stainless steel 17-4PH prior to hard chromium plating are given and discussed. Comparison is also made among these results and those obtained in the case of the chromium plated without peening and as received conditions. It was found that shot peening caused an increase of 667% in the fatigue life of stainless steel 17-4PH at 0.57 Y stress level, whereas hard chromium plating was found to reduce its fatigue life and strength. Hence, chromium plating after shot peening is recommended. (author)

  11. SunShot Vision Study: February 2012 (Book)

    Energy Technology Data Exchange (ETDEWEB)

    2012-02-01

    The objective of the SunShot Vision Study is to provide an in-depth assessment of the potential for solar technologies to meet a significant share of electricity demand in the United States during the next several decades. Specifically, it explores a future in which the price of solar technologies declines by about 75% between 2010 and 2020 - in line with the U.S. Department of Energy (DOE) SunShot Initiative's targets.

  12. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    Science.gov (United States)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-02-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  13. Biomechanical analysis of the jump shot in basketball.

    Science.gov (United States)

    Struzik, Artur; Pietraszewski, Bogdan; Zawadzki, Jerzy

    2014-09-29

    Basketball players usually score points during the game using the jump shot. For this reason, the jump shot is considered to be the most important element of technique in basketball and requires a high level of performance. The aim of this study was to compare the biomechanical characteristics of the lower limbs during a jump shot without the ball and a countermovement jump without an arm swing. The differences between variables provide information about the potential that an athlete can utilise during a game when performing a jump shot. The study was conducted among 20 second-league basketball players by means of a Kistler force plate and the BTS SMART system for motion analysis. The variables measured included the take-off time, mean power, peak power, relative mean power, jump height, maximum landing force and calculated impact ratio. Surprisingly, more advantageous variables were found for the jump shot. This finding suggests a very high performance level in the jump shot in the studied group and a maximum utilisation of their motor abilities. Both types of jumps were characterised by high mean and peak power values and average heights. The high forces at landing, which result in considerable impact ratios, may have prompted the studied group to land softly. Use of the countermovement jump without an arm swing is recommended to assess and predict the progression of player's jumping ability.

  14. Biomechanical Analysis of the Jump Shot in Basketball

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2014-10-01

    Full Text Available Basketball players usually score points during the game using the jump shot. For this reason, the jump shot is considered to be the most important element of technique in basketball and requires a high level of performance. The aim of this study was to compare the biomechanical characteristics of the lower limbs during a jump shot without the ball and a countermovement jump without an arm swing. The differences between variables provide information about the potential that an athlete can utilise during a game when performing a jump shot. The study was conducted among 20 second-league basketball players by means of a Kistler force plate and the BTS SMART system for motion analysis. The variables measured included the take-off time, mean power, peak power, relative mean power, jump height, maximum landing force and calculated impact ratio. Surprisingly, more advantageous variables were found for the jump shot. This finding suggests a very high performance level in the jump shot in the studied group and a maximum utilisation of their motor abilities. Both types of jumps were characterised by high mean and peak power values and average heights. The high forces at landing, which result in considerable impact ratios, may have prompted the studied group to land softly. Use of the countermovement jump without an arm swing is recommended to assess and predict the progression of player’s jumping ability

  15. Nanosecond pulsed laser ablation of silicon in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, R.; Anvari, J.Z.; Mansour, N. [Shahid Beheshti University, Department of Physics, Tehran (Iran)

    2009-03-15

    Laser fluence and laser shot number are important parameters for pulse laser based micromachining of silicon in liquids. This paper presents laser-induced ablation of silicon in liquids of the dimethyl sulfoxide (DMSO) and the water at different applied laser fluence levels and laser shot numbers. The experimental results are conducted using 15 ns pulsed laser irradiation at 532 nm. The silicon surface morphology of the irradiated spots has an appearance as one can see in porous formation. The surface morphology exhibits a large number of cavities which indicates as bubble nucleation sites. The observed surface morphology shows that the explosive melt expulsion could be a dominant process for the laser ablation of silicon in liquids using nanosecond pulsed laser irradiation at 532 nm. Silicon surface's ablated diameter growth was measured at different applied laser fluences and shot numbers in both liquid interfaces. A theoretical analysis suggested investigating silicon surface etching in liquid by intense multiple nanosecond laser pulses. It has been assumed that the nanosecond pulsed laser-induced silicon surface modification is due to the process of explosive melt expulsion under the action of the confined plasma-induced pressure or shock wave trapped between the silicon target and the overlying liquid. This analysis allows us to determine the effective lateral interaction zone of ablated solid target related to nanosecond pulsed laser illumination. The theoretical analysis is found in excellent agreement with the experimental measurements of silicon ablated diameter growth in the DMSO and the water interfaces. Multiple-shot laser ablation threshold of silicon is determined. Pulsed energy accumulation model is used to obtain the single-shot ablation threshold of silicon. The smaller ablation threshold value is found in the DMSO, and the incubation effect is also found to be absent. (orig.)

  16. The Mercury Laser Advances Laser Technology for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Ebbers, C A; Caird, J; Moses, E

    2009-01-21

    The National Ignition Facility (NIF) at Lawrence Livermore Laboratory is on target to demonstrate 'breakeven' - creating as much fusion-energy output as laser-energy input. NIF will compress a tiny sphere of hydrogen isotopes with 1.8 MJ of laser light in a 20-ns pulse, packing the isotopes so tightly that they fuse together, producing helium nuclei and releasing energy in the form of energetic particles. The achievement of breakeven will culminate an enormous effort by thousands of scientists and engineers, not only at Livermore but around the world, during the past several decades. But what about the day after NIF achieves breakeven? NIF is a world-class engineering research facility, but if laser fusion is ever to generate power for civilian consumption, the laser will have to deliver pulses nearly 100,000 times faster than NIF - a rate of perhaps 10 shots per second as opposed to NIF's several shots a day. The Mercury laser (named after the Roman messenger god) is intended to lead the way to a 10-shots-per-second, electrically-efficient, driver laser for commercial laser fusion. While the Mercury laser will generate only a small fraction of the peak power of NIF (1/30,000), Mercury operates at higher average power. The design of Mercury takes full advantage of the technology advances manifest in its behemoth cousin (Table 1). One significant difference is that, unlike the flashlamp-pumped NIF, Mercury is pumped by highly efficient laser diodes. Mercury is a prototype laser capable of scaling in aperture and energy to a NIF-like beamline, with greater electrical efficiency, while still running at a repetition rate 100,000 times greater.

  17. 77 FR 59158 - Migratory Bird Hunting; Application for Approval of Copper-Clad Iron Shot and Fluoropolymer Shot...

    Science.gov (United States)

    2012-09-26

    ... ``there is little variability in composition to be expected'' in production of the shot. Environ-Metal... the bulk of the coating. The pigments vary between coatings, and comprise 13.8% to 20.5% by weight of...

  18. The influence of surface contamination on the ion emission from nanosecond-pulsed laser ablation of Al and Cu

    Science.gov (United States)

    Ullah, S.; Dogar, A. H.; Qayyum, H.; Rehman, Z. U.; Qayyum, A.

    2018-04-01

    Ions emitted from planar Al and Cu targets irradiated with a 1064 nm pulsed laser were investigated with the help of a time-resolving Langmuir probe. It was found that the intensity of the ions emitted from a target area rapidly decreases with the increasing number of laser shots, and seems to reach saturation after about 10 laser shots. The saturated intensity of Al and Cu ions was approximately 0.1 and 0.3 times the intensity of the respective ions measured at the first laser shot, respectively. The higher target ion intensity for the first few shots is thought to be due to the enhanced ionization of target atoms by vacuum-ultraviolet radiations emitted from the thermally excited/ionized surface contaminants. The reduction of target ion intensity with an increasing number of laser shots thus indicates the removal of contaminants from the irradiated surface area. Laser-cleaned Al and Cu surfaces were then allowed to be recontaminated with residual vacuum gases and the ion intensity was measured at various time delays. The prolonged exposure of the cleaned target to vacuum residual gases completely restores the ion intensity. Regarding surface contaminants removal, laser shots of higher intensities were found to be more effective than a higher number of laser shots having lower intensities.

  19. Development of a Micro-shot Peening Process and Testing of Micro-shot Peened Engineering Materials

    OpenAIRE

    Vahey, James

    2006-01-01

    A precision, air blast, shot peening machine was designed and developed and used to carry out peening operations on engineering materials and components. The machine was designed to allow all the variables of the peening process to be controlled and adjusted. The micro-shot peening process was applied to a series of standard High Speed Steel twist drills, carbide inserts for milling cutters, turning tools and EPDM material. The drills were used under controlled CNC conditions to machine mild ...

  20. Manhattan Solar Cannon

    Science.gov (United States)

    Treffers, Richard R.; Loisos, George; Ubbelohde, Susan; Douglas, Susanna; Pintos, Eduardo; Mulherin, James; Pasley, David

    2015-01-01

    We describe a 2.4 m hexagonal solar collector atop a Manhattan office building used for a solar / arts project. The collector uses an afocal design to concentrate the sunlight into a 0.6 m diameter beam which is directed by mirrors into a 80 m long fiber optic sculpture which descends an interior stairwell. The collector is fully steerable and follows the sun each day robotically. The control system and the optical design of the collector as well as the fiber optic sculpture will be discussed.

  1. PeoplePersonality: Chris Clarke - a physicist who studies ice cream Teaching Anecdotes: Annie Jump Cannon Obituary: György Marx 1927-2002 Starting Out: What Katie did next: part 3 Opinions: What is really important?

    Science.gov (United States)

    2003-03-01

    Featuring relationships, personalities, interactions, environments and reputations involved in physics and education PERSONALITY (156) Chris Clarke - a physicist who studies ice cream TEACHING ANECDOTES (157) Annie Jump Cannon OBITUARY (158) György Marx 1927-2002 Steven Chapman STARTING OUT (159) What Katie did next: part 3 Katie Pennicott OPINIONS (160) What is really important? Kerry Parker

  2. Shot reproducibility of the self-magnetic-pinch diode at 4.5 MV

    OpenAIRE

    Nichelle Bennett; M. Dale Crain; Darryl W. Droemer; Raymond E. Gignac; Greg Lare; Isidro Molina; Robert Obregon; Chase C. Smith; Frank L. Wilkins; Dale R. Welch; Steve Cordova; Manuel L. Gallegos; Mark D. Johnston; Mark L. Kiefer; Joshua J. Leckbee

    2014-01-01

    In experiments conducted at Sandia National Laboratories’ RITS-6 accelerator, the self-magnetic-pinch diode exhibits significant shot-to-shot variability. Specifically, for identical hardware operated at the same voltage, some shots exhibit a catastrophic drop in diode impedance. A study is underway to identify sources of shot-to-shot variations which correlate with diode impedance collapse. The scope of this report is limited to data collected at 4.5-MV peak voltage and sources of variabilit...

  3. Numerical investigation of a shot peening process by a finite element approach

    DEFF Research Database (Denmark)

    Liu, Hongsheng; Zhang, Xiaodan; Hansen, Niels

    2014-01-01

    Shot peening is a surface impact treatment widely used to improve the performance of a metal or a component. The better performance of the shot peened part is controlled by compressive residual stresses resulting from the plastic deformation of the surface layers by impacts of shot. The compressi...... such as damping ratio of material, friction coefficient, shot velocity and shot angle on the magnitude and distribution of the compressive residual stress is examined....

  4. Picosecond laser induced periodic surface structure on copper thin films

    International Nuclear Information System (INIS)

    Huynh, Thi Trang Dai; Petit, Agnès; Semmar, Nadjib

    2014-01-01

    LIPSS (Laser Induced Periodic Surface Structure) formation on copper thin films induced by a picosecond laser beam (Nd:YAG laser at 266 nm, 42 ps and 10 Hz) was studied experimentally. Copper thin films were deposited on glass and silicon substrates by magnetron sputtering. The surface modifications of irradiated zones were analyzed by scanning electron microscopy. Two distinct types of LIPSS were identified with respect to the laser fluence (F), number of laser shots (N) and substrate material. Namely, with a number of laser shots (1000 2 2 ), Low Spatial Frequency LIPSS (LSFL with a spatial period of Λ ∼ 260 nm and an orientation perpendicular to polarization) and High Spatial Frequency LIPSS (HSFL with a spatial period of Λ ∼ 130 nm and an orientation parallel to the polarization) were observed. The regime of regular spikes formation was determined for N ≥ 1000. Moreover, the 2D-map of the relationship among LIPSS formation, laser fluence and number of laser shots on copper thin film with two different substrates was established. A physics interpretation of regular spikes and LIPSS formation on copper thin film induced by ps laser with overlapping multi-shots is proposed based on experimental data and the theory of Plateau-Rayleigh instability.

  5. Effect of shot peening on metastable austenitic stainless steels

    International Nuclear Information System (INIS)

    Fargas, G.; Roa, J.J.; Mateo, A.

    2015-01-01

    In this work, shot peening was performed in a metastable austenitic stainless steel EN 1.4318 (AISI 301LN) in order to evaluate its effect on austenite to martensite phase transformation and also the influence on the fatigue limit. Two different steel conditions were considered: annealed, i.e., with a fully austenitic microstructure, and cold rolled, consisting of a mixture of austenite and martensite. X-ray diffraction, electron back-scattered diffraction and focus ion beam, as well as nanoindentation techniques, were used to elucidate deformation mechanisms activated during shot peening and correlate with fatigue response. Results pointed out that extensive plastic deformation and phase transformation developed in annealed specimens as a consequence of shot peening. However, the increase of roughness and the generation of microcracks led to a limited fatigue limit improvement. In contrast, shot peened cold rolled specimens exhibited enhanced fatigue limit. In the latter case, the main factor that determined the influence on the fatigue response was the distance from the injector, followed successively by the exit speed of the shots and the coverage factor

  6. INCREASED DISTANCE OF SHOOTING ON BASKETBALL JUMP SHOT

    Directory of Open Access Journals (Sweden)

    Victor Hugo Alves Okazaki

    2012-06-01

    Full Text Available The present study analyzed the effect of increased distance on basketball jump shot outcome and performance. Ten male expert basketball players were filmed and a number of kinematic variables analyzed during jump shot that were performed from three conditions to represent close, intermediate and far distances (2.8, 4.6, and 6.4m, respectively. Shot accuracy decreased from 59% (close to 37% (far, in function of the task constraints (p < 0.05. Ball release height decreased (p < 0.05 from 2.46 m (close to 2.38m (intermediate and to 2.33m (long. Release angle also decreased (p < 0.05 when shot was performed from close (78.92° in comparison to intermediate distances (65.60°. While, ball release velocity increased (p < 0.05 from 4.39 m/s (close to 5.75 m·s-1 (intermediate to 6.89 m·s-1 (far. These changes in ball release height, angle and velocity, related to movement performance adaptations were suggested as the main factors that influence jump shot accuracy when distance is augmented

  7. The Effect of Multiple Shot Peening on the Corrosion Behavior of Duplex Stainless Steel

    Science.gov (United States)

    Feng, Qiang; She, Jia; Wu, Xueyan; Wang, Chengxi; Jiang, Chuanhai

    2018-03-01

    Various types of shot peening treatments were applied to duplex stainless steel. The effects of shot peening intensity and working procedures on the microstructure were investigated. The domain size and microstrain evolution in the surface layer were characterized utilizing the Rietveld method. As the shot peening intensity increased, the surface roughness increased in the surface layer; however, it decreased after multiple (dual and triple) shot peening. The mole fraction of strain-induced martensite as a function of the intensity of shot peening was evaluated by XRD measurements. Both potentiodynamic polarization curves and salt spray tests of shot-peened samples in NaCl solution were investigated. The results indicate that traditional shot peening has negative effects on corrosion resistance with increasing shot peening intensity; however, the corrosion rate can be reduced by means of multiple shot peening.

  8. Superpoissonian shot noise in organic magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Cascales, Juan Pedro; Martinez, Isidoro; Aliev, Farkhad G., E-mail: farkhad.aliev@uam.es [Dpto. Fisica Materia Condensada C3, Instituto Nicolas Cabrera (INC), Condensed Matter Physics Institute (IFIMAC), Universidad Autonoma de Madrid, Madrid 28049 (Spain); Hong, Jhen-Yong; Lin, Minn-Tsong, E-mail: mtlin@phys.ntu.edu.tw [Department of Physics, National Taiwan University, Taipei 10617, Taiwan and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Szczepański, Tomasz; Dugaev, Vitalii K. [Department of Physics, Rzeszów University of Technology, al. Powstańców Warszawy 6, 35-959 Rzeszów (Poland); Barnaś, Józef [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland and Institute of Molecular Physics, Polish Academy of Sciences, ul. Smoluchowskiego 17, 60-179 Poznań (Poland)

    2014-12-08

    Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here, we investigate conductance and shot noise in magnetic tunnel junctions with 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA) barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10% and 40%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5–2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.

  9. Observability of radiation-pressure shot noise in optomechanical systems

    International Nuclear Information System (INIS)

    Boerkje, K.; Nunnenkamp, A.; Zwickl, B. M.; Yang, C.; Harris, J. G. E.; Girvin, S. M.

    2010-01-01

    We present a theoretical study of an experiment designed to detect radiation-pressure shot noise in an optomechanical system. Our model consists of a coherently driven optical cavity mode that is coupled to a mechanical oscillator. We examine the cross-correlation between two quadratures of the output field from the cavity. We determine under which circumstances radiation-pressure shot noise can be detected by a measurement of this cross-correlation. This is done in the general case of nonzero detuning between the frequency of the drive and the cavity resonance frequency. We study the qualitative features of the different contributions to the cross-correlator and provide quantitative figures of merit for the relative importance of the radiation-pressure shot noise contribution to other contributions. We also propose a modified setup of this experiment relevant to the 'membrane-in-the-middle' geometry, which potentially can avoid the problems of static bistability and classical noise in the drive.

  10. Intra-shot MSE Calibration Technique For LHCD Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Jinseok; Scott, Steve; Shiraiwa, Syun' ichi; Greenwald, Martin; Parker, Ronald; Wallace, Gregory

    2009-11-23

    The spurious drift in pitch angle of order several degrees measured by the Motional Stark Effect (MSE) diagnostic in the Alcator C-Mod tokamak1 over the course of an experimental run day has precluded direct utilization of independent absolute calibrations. Recently, the underlying cause of the drift has been identified as thermal stress-induced birefringence in a set of in-vessel lenses. The shot-to-shot drift can be avoided by using MSE to measure only the change in pitch angle between a reference phase and a phase of physical interest within a single plasma discharge. This intra-shot calibration technique has been applied to the Lower Hybrid Current Drive (LHCD) experiments and the measured current profiles qualitatively demonstrate several predictions of LHCD theory such as an inverse dependence of current drive efficiency on the parallel refractive index and the presence of off-axis current drive.

  11. Spin-dependent shot noise in semiconductor and graphene nanostructures

    Science.gov (United States)

    Dragomirova, Ralitsa L.

    Shot noise is the name given to the time-dependent non-equilibrium current (or voltage) fluctuations which persist down to zero temperature and are fundamentally related to the discrete nature of the electron charge. Over the past two decades it has become a major tool for gathering information about microscopic mechanisms of transport and correlations between charges which cannot be extracted from traditional conductance measurements. Recently a handful of theoretical and experimental studies have suggested that shot noise in systems with spin-dependent interactions provides a sensitive probe to differentiate between scattering from magnetic impurities, spin-flip scattering, and continuous spin precession effects on semiclassical or quantum transport of injected spin-polarized currents. This is due to the fact that any spin flip converts spin-↑ subsystem particle into a spin-↓ subsystem particle, where the two subsystems differ when spin degeneracy is lifted. Thus, the nonconservation of the number of particles in each subsystem generates additional source of current fluctuations. Here we generalize the scattering theory of quantum shot noise to include the full spin-density matrix of electrons. This formalism yields the spin-resolved shot noise power applicable for a generic spintronic device where partially polarized charge current or even pure spin current is injected from a spin-filtering or ferromagnetic electrode into a quantum-coherent nanostructure governed by arbitrary spin-dependent interactions. The developed formalism [2, 5] is applied in Chapter 5 to diffusive multichannel quantum wires with the Rashba spin-orbit (SO) coupling sandwiched between ferromagnetic source and ferromagnetic or normal drain electrodes. The crucial role played by the SO interactions in all-electrical control of spin in semiconductor nanostructures has ignited recent studies of their signatures on the shot noise. We investigate what is the effect of the Rahsba SO coupling

  12. Analysis of shot-to-shot variability in post-disruption runaway electron currents for diverted DIII-D discharges

    International Nuclear Information System (INIS)

    Izzo, V A; Humphreys, D A; Kornbluth, M

    2012-01-01

    In DIII-D experiments, rapid termination by Ar-pellet injection sometimes produces a post-termination runaway electron (RE) current plateau, but this effect is highly non-reproducible on a shot-to-shot basis, particularly for diverted target plasmas. A set of DIII-D discharges is analyzed with two MHD codes to understand the relationship between the current profile of the target plasma and the amplitude of the RE current plateau. Using the linear stability code GATO, a correlation between the radial profile of the unstable n = 1 mode just after Ar-pellet injection and the observed appearance of an RE plateau is identified. Nonlinear NIMROD simulations with RE test-particle calculations directly predict RE confinement times during the disruption. With one exception, NIMROD predicts better RE confinement for shots in which higher RE currents were observed in DIII-D. But, the variation in confinement is primarily connected to the saturated n = 1 mode amplitude and not its radial profile. Still, both sets of analyses support the hypothesis that RE deconfinement by MHD fluctuations is a major factor in the shot-to-shot variability of RE plateaus, though additional factors such as seed current amplitude cannot be ruled out. (paper)

  13. Analysis of shot-to-shot variability in post-disruption runaway electron currents for diverted DIII-D discharges

    Science.gov (United States)

    Izzo, V. A.; Humphreys, D. A.; Kornbluth, M.

    2012-09-01

    In DIII-D experiments, rapid termination by Ar-pellet injection sometimes produces a post-termination runaway electron (RE) current plateau, but this effect is highly non-reproducible on a shot-to-shot basis, particularly for diverted target plasmas. A set of DIII-D discharges is analyzed with two MHD codes to understand the relationship between the current profile of the target plasma and the amplitude of the RE current plateau. Using the linear stability code GATO, a correlation between the radial profile of the unstable n = 1 mode just after Ar-pellet injection and the observed appearance of an RE plateau is identified. Nonlinear NIMROD simulations with RE test-particle calculations directly predict RE confinement times during the disruption. With one exception, NIMROD predicts better RE confinement for shots in which higher RE currents were observed in DIII-D. But, the variation in confinement is primarily connected to the saturated n = 1 mode amplitude and not its radial profile. Still, both sets of analyses support the hypothesis that RE deconfinement by MHD fluctuations is a major factor in the shot-to-shot variability of RE plateaus, though additional factors such as seed current amplitude cannot be ruled out.

  14. Effect of multi-shot X-ray exposures in IFE armor materials

    International Nuclear Information System (INIS)

    Latkowski, J.F.; Abbott, R.P.; Schmitt, R.C.; Bell, B.K.

    2005-01-01

    As part of the High Average Power Laser (HAPL) program the performance of tungsten as an armor material is being studied. While the armor would be exposed to neutrons, X-rays and ions within an inertial fusion energy (IFE) power plant, the thermomechanical effects are believed to dominate. Using a pulsed X-ray source, long-term exposures of tungsten have been completed at fluences that are of interest for the IFE application. Modeling is used in conjunction with experiments on the XAPPER X-ray damage facility in an effort to recreate the effects that would be expected in an operating IFE power plant. X-ray exposures have been completed for a variety of X-ray fluences and number of shots. Analysis of the samples suggests that surface roughening has a threshold that is very close to the fluences that reproduce the peak temperatures expected in an IFE armor material

  15. Single shot near edge x-ray absorption fine structure spectroscopy in the laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Mantouvalou, I., E-mail: ioanna.mantouvalou@tu-berlin.de; Witte, K.; Martyanov, W.; Jonas, A.; Grötzsch, D.; Kanngießer, B. [Institute for Optics and Atomic Physics, Technical University of Berlin, D-10623 Berlin (Germany); Streeck, C. [Physikalisch-Technische Bundesanstalt (PTB), D-10587 Berlin (Germany); Löchel, H.; Rudolph, I.; Erko, A. [Helmholtz-Zentrum Berlin, D-14109 Berlin (Germany); Stiel, H. [Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, D-12489 Berlin (Germany)

    2016-05-16

    With the help of adapted off-axis reflection zone plates, near edge X-ray absorption fine structure spectra at the C and N K-absorption edge have been recorded using a single 1.2 ns long soft X-ray pulse. The transmission experiments were performed with a laser-produced plasma source in the laboratory rendering time resolved measurements feasible independent on large scale facilities. A resolving power of E/ΔE ∼ 950 at the respective edges could be demonstrated. A comparison of single shot spectra with those collected with longer measuring time proves that all features of the used reference samples (silicon nitrate and polyimide) can be resolved in 1.2 ns. Hence, investigations of radiation sensitive biological specimen become possible due to the high efficiency of the optical elements enabling low dose experiments.

  16. Superhydrophobic Copper Surfaces by Shot Peening and Chemical Treatment

    Science.gov (United States)

    Forooshani, H. Mojiri; Aliofkhazraei, M.; Rouhaghdam, A. Sabour

    In this paper, superhydrophobic surfaces are developed on polycrystalline copper using a combination of mechanical and chemical treatments by shot peening, dislocation etching and stearic acid treatment. The key point in this combined approach is the fabrication of a dislocation forest by shot peening. These sites were dissolved by etching, and hierarchical structures were fabricated. When these etched surfaces are treated by stearic acid, which has low surface energy, they become superhydrophobic with contact angle more than 150∘. Because of the superior properties and low costs involved with this method, it is expected to be widely used in the industry to fabricate superhydrophobic surfaces.

  17. Effect of shot peening on steam generator tube cracking risks

    International Nuclear Information System (INIS)

    Lannoy, A.

    1993-01-01

    One of the main SG tube degradation modes in stress corrosion cracking on the primary side in the tube/tube plate roll transition zone. With a view to mitigating these cracking risks, on the 900 MWe PWR's plant, the SG inner tube walls were mechanically stress-relieved by shot peening. Between 1985 and 1988, periodic eddy current testing were performed during refuelling outages before and after the shot peening that allows to monitor the number and condition of affected tubes versus time in service. Statistical analysis were performed in order to test and quantify the effects of this treatment. (author). 3 figs., 2 refs

  18. Preparation of Ultracold Atom Clouds at the Shot Noise Level

    DEFF Research Database (Denmark)

    Gajdacz, M.; Hilliard, A. J.; Kristensen, Mick

    2016-01-01

    We prepare number stabilized ultracold atom clouds through the real-time analysis of nondestructive images and the application of feedback. In our experiments, the atom number N∼10^6 is determined by high precision Faraday imaging with uncertainty ΔN below the shot noise level, i.e., ΔN... on this measurement, feedback is applied to reduce the atom number to a user-defined target, whereupon a second imaging series probes the number stabilized cloud. By this method, we show that the atom number in ultracold clouds can be prepared below the shot noise level....

  19. Continuous Variable Quantum Key Distribution with a Noisy Laser

    DEFF Research Database (Denmark)

    Jacobsen, Christian Scheffmann; Gehring, Tobias; Andersen, Ulrik Lund

    2015-01-01

    Existing experimental implementations of continuous-variable quantum key distribution require shot-noise limited operation, achieved with shot-noise limited lasers. However, loosening this requirement on the laser source would allow for cheaper, potentially integrated systems. Here, we implement...... a theoretically proposed prepare-and-measure continuous-variable protocol and experimentally demonstrate the robustness of it against preparation noise stemming for instance from technical laser noise. Provided that direct reconciliation techniques are used in the post-processing we show that for small distances...

  20. Techniques for preventing damage to high power laser components

    International Nuclear Information System (INIS)

    Stowers, I.F.; Patton, H.G.; Jones, W.A.; Wentworth, D.E.

    1977-09-01

    Techniques for preventing damage to components of the LASL Shiva high power laser system were briefly presented. Optical element damage in the disk amplifier from the combined fluence of the primary laser beam and the Xenon flash lamps that pump the cavity was discussed. Assembly and cleaning techniques were described which have improved optical element life by minimizing particulate and optically absorbing film contamination on assembled amplifier structures. A Class-100 vertical flaw clean room used for assembly and inspection of laser components was also described. The life of a disk amplifier was extended from less than 50 shots to 500 shots through application of these assembly and cleaning techniques

  1. Dye laser spectrometer for the analysis of pulsed vacuum arcs

    International Nuclear Information System (INIS)

    Hargis, P.J. Jr.; Robertson, M.M.

    1975-01-01

    A pulsed dye laser spectrometer which is used to obtain detailed single shot spectroscopic measurements of the plasma in a pulsed vacuum arc was developed. The capabilities of this spectrometer are indicated by the detection of laser induced fluorescence signals from 10 6 neutral Ti atoms in the plasma of a pulsed vacuum arc with a Ti anode. (U.S.)

  2. Femtosecond Single-Shot Imaging of Nanoscale Ferromagnetic Order in Co/Pd Multilayers using Resonant X-ray Holography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tianhan; Zhu, Diling; Benny Wu,; Graves, Catherine; Schaffert, Stefan; Rander, Torbjorn; Muller, leonard; Vodungbo, Boris; Baumier, Cedric; Bernstein, David P.; Brauer, Bjorn; Cros, Vincent; Jong, Sanne de; Delaunay, Renaud; Fognini, Andreas; Kukreja, Roopali; Lee, Sooheyong; Lopez-Flores, Victor; Mohanty, Jyoti; Pfau, Bastian; Popescu, 5 Horia

    2012-05-15

    We present the first single-shot images of ferromagnetic, nanoscale spin order taken with femtosecond x-ray pulses. X-ray-induced electron and spin dynamics can be outrun with pulses shorter than 80 fs in the investigated fluence regime, and no permanent aftereffects in the samples are observed below a fluence of 25 mJ/cm{sup 2}. Employing resonant spatially-muliplexed x-ray holography results in a low imaging threshold of 5 mJ/cm{sup 2}. Our results open new ways to combine ultrafast laser spectroscopy with sequential snapshot imaging on a single sample, generating a movie of excited state dynamics.

  3. LIL laser performance status

    International Nuclear Information System (INIS)

    Julien, X.; Adolf, A.; Bar, E.; Beau, V.; Bordenave, E.; Chies, Th.; Courchinoux, R.; Feral, Ch.; Gendeau, P.; Graillot, H.; Grosset-Grange, C.; Henry, O.; Higonenq, V.; Journot, E.; Lacampagne, L.; Lafond, E.; Le Deroff, L.; Martinez, A.; Patissou, L.; Roques, A.; Thauvin, L.; Di-Nicola, J.M.; Thiell, G.

    2011-01-01

    The Laser Integration Line (LIL) was first designed as a prototype to validate the concepts and the laser architecture of the Laser MegaJoule (LMJ). The LIL facility is a 4-beam laser representing a quad structure of the LMJ. A set of test campaigns were conducted to safely ramp up laser performance. The main goal was to measure quad-specific features such as beam synchronization and focal spot (size, smoothing contrast ratio or irradiation nonuniformity) versus the LMJ requirements. Following the laser commissioning, the LIL has become a major instrument dedicated to the achievement of plasma physics experiments for the French Simulation Program and was also opened to the academic scientific community. One of the attributes of the LIL facility is to be very flexible to accommodate the requests of plasma physicists during campaigns. The LIL is constantly evolving to best meet the needs of target physicists. Changes made or planned are either to improve the quality of laser beams, or to increase the LIL Energy-Power operating space. To optimize preparation and design of shot campaigns, the LIL performance status has been elaborated. It gives information about the characteristics of the laser in terms of near field and far field, defines the steps to maintain performance, explains how the facility responds to the request, details settings (smoothing, shaping of the focal spot, energy, temporal pulse shaping, beam pointing) and gives the limits in energy and power. In this paper, an overview of the LIL performance is presented. (authors)

  4. Data acquisition system for fusion diagnostics on the ARGUS laser

    International Nuclear Information System (INIS)

    Greenwood, J.R.; Campbell, D.E.; Frerking, C.E.

    1976-09-01

    An extensive data acquisition and analysis system has been implemented for experiments on the ARGUS laser. The system is based upon a PDP-11/40 minicomputer and CAMAC interfaces. Highspeed transient digitizers, calorimeter digitizing modules and time integrated data are interfaced through CAMAC over a fiber optic serial highway. The system allows for dynamic definition of the experimental environment by an operator, automatic data acquisition during a shot. Two interactive graphics terminals allow experimenters real-time access to target shot data

  5. Multivariate Product-Shot-noise Cox Point Process Models

    DEFF Research Database (Denmark)

    Jalilian, Abdollah; Guan, Yongtao; Mateu, Jorge

    We introduce a new multivariate product-shot-noise Cox process which is useful for model- ing multi-species spatial point patterns with clustering intra-specific interactions and neutral, negative or positive inter-specific interactions. The auto and cross pair correlation functions of the process...

  6. One-shot valve may be remotely actuated

    Science.gov (United States)

    Kami, S.

    1965-01-01

    One-shot valve, with spring-loaded plunger and sealing diaphragm, incorporates an emergency release actuated by a remote sensor. The plunger is released by the electrical melting of a fuse link and pierces the valve seal. The valve lowers fluid pressure in a container without losing the contained fluid.

  7. SnapShot: Visualization to Propel Ice Hockey Analytics.

    Science.gov (United States)

    Pileggi, H; Stolper, C D; Boyle, J M; Stasko, J T

    2012-12-01

    Sports analysts live in a world of dynamic games flattened into tables of numbers, divorced from the rinks, pitches, and courts where they were generated. Currently, these professional analysts use R, Stata, SAS, and other statistical software packages for uncovering insights from game data. Quantitative sports consultants seek a competitive advantage both for their clients and for themselves as analytics becomes increasingly valued by teams, clubs, and squads. In order for the information visualization community to support the members of this blossoming industry, it must recognize where and how visualization can enhance the existing analytical workflow. In this paper, we identify three primary stages of today's sports analyst's routine where visualization can be beneficially integrated: 1) exploring a dataspace; 2) sharing hypotheses with internal colleagues; and 3) communicating findings to stakeholders.Working closely with professional ice hockey analysts, we designed and built SnapShot, a system to integrate visualization into the hockey intelligence gathering process. SnapShot employs a variety of information visualization techniques to display shot data, yet given the importance of a specific hockey statistic, shot length, we introduce a technique, the radial heat map. Through a user study, we received encouraging feedback from several professional analysts, both independent consultants and professional team personnel.

  8. Assessment for One-Shot Library Instruction: A Conceptual Approach

    Science.gov (United States)

    Wang, Rui

    2016-01-01

    The purpose of this study is to explore a conceptual approach to assessment for one-shot library instruction. This study develops a new assessment instrument based on Carol Kuhlthau's information search process (ISP) model. The new instrument focuses on measuring and identifying changes in student readiness to do research along three…

  9. ON THE USE OF SHOT NOISE FOR PHOTON COUNTING

    International Nuclear Information System (INIS)

    Zmuidzinas, Jonas

    2015-01-01

    Lieu et al. have recently claimed that it is possible to substantially improve the sensitivity of radio-astronomical observations. In essence, their proposal is to make use of the intensity of the photon shot noise as a measure of the photon arrival rate. Lieu et al. provide a detailed quantum-mechanical calculation of a proposed measurement scheme that uses two detectors and conclude that this scheme avoids the sensitivity degradation that is associated with photon bunching. If correct, this result could have a profound impact on radio astronomy. Here I present a detailed analysis of the sensitivity attainable using shot-noise measurement schemes that use either one or two detectors, and demonstrate that neither scheme can avoid the photon bunching penalty. I perform both semiclassical and fully quantum calculations of the sensitivity, obtaining consistent results, and provide a formal proof of the equivalence of these two approaches. These direct calculations are furthermore shown to be consistent with an indirect argument based on a correlation method that establishes an independent limit to the sensitivity of shot-noise measurement schemes. Furthermore, these calculations are directly applicable to the regime of interest identified by Lieu et al. Collectively, these results conclusively demonstrate that the photon-bunching sensitivity penalty applies to shot-noise measurement schemes just as it does to ordinary photon counting, in contradiction to the fundamental claim made by Lieu et al. The source of this contradiction is traced to a logical fallacy in their argument

  10. SunShot Catalyst Prize Competition Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Solar Energy Technologies Office

    2015-04-01

    This fact sheet is an overview of the Catalyst Energy Innovation Prize, an open innovation program launched in 2014 by the U.S. Department of Energy SunShot Initiative. This program aims to catalyze the rapid creation and development of products and solutions that address near-term challenges in the U.S. solar energy marketplace.

  11. Flu Shots, Mammogram, and the Perception of Probabilities

    NARCIS (Netherlands)

    Carman, K.G.; Kooreman, P.

    2010-01-01

    We study individuals’ decisions to decline or accept preventive health care interventions such as flu shots and mammograms. In particular, we analyze the role of perceptions of the effectiveness of the intervention, by eliciting individuals' subjective probabilities of sickness and survival, with

  12. SnapShot: O-Glycosylation Pathways across Kingdoms

    DEFF Research Database (Denmark)

    Joshi, Hiren J.; Narimatsu, Yoshiki; Schjoldager, Katrine T.

    2018-01-01

    O-glycosylation is one of the most abundant and diverse types of post-translational modifications of proteins. O-glycans modulate the structure, stability, and function of proteins and serve generalized as well as highly specific roles in most biological processes. This ShapShot presents types of......-glycans found in different organisms and their principle biosynthetic pathways...

  13. DOE SunShot System Integration Program. Accomplishments and Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Boynton, Shannon [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-02-01

    During FY15, Sandia National Laboratories executed research and development (R&D) work on a portfolio of 16 SunShot Program Systems Integration (SI) agreements, with a total FY15 budget of $13.2 million. This document summarizes the impact of the Sandia contributions based on Sandia’s direct contributions by DOE.

  14. Gaze Embeddings for Zero-Shot Image Classification

    NARCIS (Netherlands)

    Karessli, N.; Akata, Z.; Schiele, B.; Bulling, A.

    2017-01-01

    Zero-shot image classification using auxiliary information, such as attributes describing discriminative object properties, requires time-consuming annotation by domain experts. We instead propose a method that relies on human gaze as auxiliary information, exploiting that even non-expert users have

  15. Opening Shots and Loose Slots: adapting Las Vegas

    NARCIS (Netherlands)

    Goggin, J.

    2015-01-01

    Anyone who has ever seen a film set in Las Vegas will be familiar with opening shots of sensational neon signage clustered against the night sky. This montage sequence, now an established convention, leads the viewer on a thrilling joy-ride, generally beginning on Fremont Street in the old city

  16. Movement symmetry and asymmetry of goal shots in female football ...

    African Journals Online (AJOL)

    This study examined the phenomenon of symmetrical skills in goal shot technique in female football players, of nine video recorded matches. The recording was taken during the 2nd Under 19 female football World Cup in 2004 and the 6th European female Championships of female seniors in 2005. The study comprised ...

  17. Lower Extremity Muscle Activity During a Women's Overhand Lacrosse Shot

    Directory of Open Access Journals (Sweden)

    Millard Brianna M.

    2014-07-01

    Full Text Available The purpose of this study was to describe lower extremity muscle activity during the lacrosse shot. Participants (n=5 females, age 22±2 years, body height 162.6±15.2 cm, body mass 63.7±23.6 kg were free from injury and had at least one year of lacrosse experience. The lead leg was instrumented with electromyography (EMG leads to measure muscle activity of the rectus femoris (RF, biceps femoris (BF, tibialis anterior (TA, and medial gastrocnemius (GA. Participants completed five trials of a warm-up speed shot (Slow and a game speed shot (Fast. Video analysis was used to identify the discrete events defining specific movement phases. Full-wave rectified data were averaged per muscle per phase (Crank Back Minor, Crank Back Major, Stick Acceleration, Stick Deceleration. Average EMG per muscle was analyzed using a 4 (Phase x 2 (Speed ANOVA. BF was greater during Fast vs. Slow for all phases (p0.05. RF and GA were each influenced by the interaction of Phase and Speed (p<0.05 with GA being greater during Fast vs. Slow shots during all phases and RF greater during Crank Back Minor and Major as well as Stick Deceleration (p<0.05 but only tended to be greater during Stick Acceleration (p=0.076 for Fast vs. Slow. The greater muscle activity (BF, RF, GA during Fast vs. Slow shots may have been related to a faster approach speed and/or need to create a stiff lower extremity to allow for faster upper extremity movements.

  18. Reader Perception of Newspaper Mug Shot Subjects in Photos and in Stories.

    Science.gov (United States)

    Lain, Laurence B.

    A study investigated whether newspaper mug shots are perceived by readers as being positive or negative in tone and whether the mug shots that are selected match the roles of their subjects in accompanying stories. Twenty-three news and feature stories with associated mug shots were clipped from seven daily newspapers. Pictures and stories were…

  19. Movement Analysis Applied to the Basketball Jump Shot--Part II.

    Science.gov (United States)

    Martin, Thomas P.

    1981-01-01

    The jump shot is one of the most important shots in the game of basketball. The movement analysis of the jump shot designates four phases: (1) preparatory position; (2) movement phase I (crouch); (3) movement phase II (jump); and (4) follow-through. (JN)

  20. An investigation of the properties of conventional and severe shot peened low alloy steel

    Science.gov (United States)

    Quang Trung, Pham; Butler, David Lee; Win Khun, Nay

    2017-07-01

    The effects of the conventional shot peening and severe shot peening process on the mechanical and tribological properties of shot peened AISI 4340 high strength steel were systematically investigated. Compared with the conventional shot peened sample, the ultrafine grain surface layer with a depth of about 20 µm generated by the severe shot peening process can enhance the hardness and wear resistance of the treated material. However, deeper dimples generated by the high media velocity in the severe shot peening process resulted in a higher surface roughness, which is considered as a side effect of this method reducing the fatigue life of the material. Applying a smaller shot size with an appropriate intensity can be used to peen the severe shot peened samples to not only reduce the surface roughness and friction coefficient but also improve the wear resistance for these samples. This work was presented in the shot peening section during ‘The 30th International Conference on Surface Modification Technologies, 2016, Milan, Italy’ (SMT30, ID 61, entitled ‘Comparison of the effects of conventional shot peening and severe shot peening processes on the mechanical and tribological properties of shot peened AISI 4340’) and the authors were encouraged to submit a manuscript to the Materials Research Express journal after adding some nessesary information.

  1. A systematic examination of the bone destruction pattern of the two-shot technique

    Directory of Open Access Journals (Sweden)

    Marcus Stoetzer

    2014-01-01

    Full Text Available Introduction: The two-shot technique is an effective stopping power method. The precise mechanisms of action on the bone and soft-tissue structures of the skull; however, remain largely unclear. The aim of this study is to compare the terminal ballistics of the two-shot and single-shot techniques. Materials and Methods: 40 fresh pigs′ heads were randomly divided into 4 groups (n = 10. Either a single shot or two shots were fired at each head with a full metal jacket or a semi-jacketed bullet. Using thin-layer computed tomography and photography, the diameter of the destruction pattern and the fractures along the bullet path were then imaged and assessed. Results: A single shot fired with a full metal jacket bullet causes minor lateral destruction along the bullet path. With two shots fired with a full metal jacket bullet, however, the maximum diameter of the bullet path is significantly greater (P < 0.05 than it is with a single shot fired with a full metal jacket bullet. In contrast, the maximum diameter with a semi-jacketed bullet is similar with the single-shot and two-shot techniques. Conclusion: With the two-shot technique, a full metal jacket bullet causes a destruction pattern that is comparable to that of a single shot fired with a semi-jacketed bullet.

  2. X-Ray Emission Spectrometer Design with Single-Shot Pump-Probe and Resonant Excitation Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Spoth, Katherine; /SUNY, Buffalo /SLAC

    2012-08-28

    Core-level spectroscopy in the soft X-ray regime is a powerful tool for the study of chemical bonding processes. The ultrafast, ultrabright X-ray pulses generated by the Linac Coherent Light Source (LCLS) allow these reactions to be studied in greater detail than ever before. In this study, we investigated a conceptual design of a spectrometer for the LCLS with imaging in the non-dispersive direction. This would allow single-shot collection of X-ray emission spectroscopy (XES) measurements with varying laser pump X-ray probe delay or a variation of incoming X-ray energy over the illuminated area of the sample. Ray-tracing simulations were used to demonstrate how the components of the spectrometer affect its performance, allowing a determination of the optimal final design. These simulations showed that the spectrometer's non-dispersive focusing is extremely sensitive to the size of the sample footprint; the spectrometer is not able to image a footprint width larger than one millimeter with the required resolution. This is compatible with a single shot scheme that maps out the laser pump X-ray probe delay in the non-dispersive direction as well as resonant XES applications at normal incidence. However, the current capabilities of the Soft X-Ray (SXR) beamline at the LCLS do not produce the required energy range in a small enough sample footprint, hindering the single shot resonant XES application at SXR for chemical dynamics studies at surfaces. If an upgraded or future beamline at LCLS is developed with lower monochromator energy dispersion the width can be made small enough at the required energy range to be imaged by this spectrometer design.

  3. Effects of shot peening pressure, media type and double shot peening on the microstructure, mechanical and tribological properties of low-alloy steel

    Science.gov (United States)

    Quang Trung, Pham; Win Khun, Nay; Butler, David Lee

    2016-12-01

    The effects of different shot peening conditions such as pressure (from 68.9-551.6 kPa), media type (media S230 and S110) and double shot peening on the microstructure, mechanical and tribological properties of shot peened AISI 4340 low-alloy steels, were systematically investigated. Their surface topography, hardness and roughness were analyzed by scanning electron microscopy, a Vickers micro-hardness tester and surface profilometer, respectively, while the cross-sectional sub-surface structures of the as-received and shot peened samples were characterized by means of optical microscopy and nanoindentation. The tribological properties were determined by using a ball-on-disc micro-tribological tester. It was shown that shot peening pressure and media type had a significant effect on the surface roughness, hardness, microstructure, wear resistance and friction of the shot peened AISI 4340 steel samples. It also indicated that the double shot peening process was a promising treatment, not only to reduce the surface roughness of the material after undergoing the first shot peening process with large media and high intensity, but to improve the tribological properties of the shot peened material.

  4. Wavefront correction for static and dynamic aberrations to within 1 second of the system shot in the NIF Beamlet demonstration facility

    International Nuclear Information System (INIS)

    Hartley, R.; Kartz, M.; Behrendt, W.

    1996-10-01

    The laser wavefront of the NIF Beamlet demonstration system is corrected for static aberrations with a wavefront control system. The system operates closed loop with a probe beam prior to a shot and has a loop bandwidth of about 3 Hz. However, until recently the wavefront control system was disabled several minutes prior to the shot to allow time to manually reconfigure its attenuators and probe beam insertion mechanism to shot mode. Thermally-induced dynamic variations in gas density in the Beamlet main beam line produce significant wavefront error. After about 5-8 seconds, the wavefront error has increased to a new, higher level due to turbulence- induced aberrations no longer being corrected- This implies that there is a turbulence-induced aberration noise bandwidth of less than one Hertz, and that the wavefront controller could correct for the majority of turbulence-induced aberration (about one- third wave) by automating its reconfiguration to occur within one second of the shot, This modification was recently implemented on Beamlet; we call this modification the t 0 -1 system

  5. Multiple beam directors for naval free electron laser weapons

    OpenAIRE

    Mitchell, Ethan D.

    2004-01-01

    Approved for public release, distribution is unlimited The Free Electron Laser has the potential to become a revolutionary weapon system. Deep magazines, low cost-per-shot, pinpoint accuracy, and speed of light delivery give this developing weapon system significant advantages over conventional systems. One limiting factor in high energy laser implementation is thermal blooming, a lensing effect which is caused by the quick heating of the atmosphere, so that the laser beam does not focus o...

  6. The Distribution of the Interval between Events of a Cox Process with Shot Noise Intensity

    Directory of Open Access Journals (Sweden)

    Angelos Dassios

    2008-01-01

    Full Text Available Applying piecewise deterministic Markov processes theory, the probability generating function of a Cox process, incorporating with shot noise process as the claim intensity, is obtained. We also derive the Laplace transform of the distribution of the shot noise process at claim jump times, using stationary assumption of the shot noise process at any times. Based on this Laplace transform and from the probability generating function of a Cox process with shot noise intensity, we obtain the distribution of the interval of a Cox process with shot noise intensity for insurance claims and its moments, that is, mean and variance.

  7. On the Path to SunShot - Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-05-01

    The halfway mark of the SunShot Initiative’s 2020 target date is a good time to take stock: How much progress has been made? What have we learned? What barriers and opportunities must still be addressed to ensure that solar technologies achieve cost parity in 2020 and realize their full potential in the decades beyond? To answer these questions, the Solar Energy Technology Office launched the On the Path to SunShot series in early 2015 in collaboration with the National Renewable Energy Laboratory (NREL) and with contributions from Lawrence Berkeley National Laboratory (LBNL), Sandia National Laboratories (SNL), and Argonne National Laboratory (ANL). The reports focus on the areas of technology development, systems integration, and market enablers.

  8. Video Shot Boundary Recognition Based on Adaptive Locality Preserving Projections

    Directory of Open Access Journals (Sweden)

    Yongliang Xiao

    2013-01-01

    Full Text Available A novel video shot boundary recognition method is proposed, which includes two stages of video feature extraction and shot boundary recognition. Firstly, we use adaptive locality preserving projections (ALPP to extract video feature. Unlike locality preserving projections, we define the discriminating similarity with mode prior probabilities and adaptive neighborhood selection strategy which make ALPP more suitable to preserve the local structure and label information of the original data. Secondly, we use an optimized multiple kernel support vector machine to classify video frames into boundary and nonboundary frames, in which the weights of different types of kernels are optimized with an ant colony optimization method. Experimental results show the effectiveness of our method.

  9. Fraction in shot-put: A learning trajectory

    Science.gov (United States)

    Putri, R. I. I.; Zulkardi

    2017-08-01

    This research was aimed to produce a learning trajectory that can help students in the fractions learning by using shot-put context at the fourth grade. The method used in this research was research design which has three stages: preparing for the experiment, the design experiment, and the retrospective analysis. Data collection techniques used was interviews, video recordings and photographs, written tests, observation and field notes. This research involved six students who have the high capability, medium capability and low capability at the first cycle and 34 students at the second cycle. The research which was conducted produced learning trajectory that consisted of a series of learning in three mathematics activities. The results showed that by using shot-put context can help students in subtraction of fractions learning and can solve the problems dealing with subtraction of fractions in daily life by using PMRI.

  10. Project Rulison: post-shot plans and evaluations

    Energy Technology Data Exchange (ETDEWEB)

    1969-12-01

    Project Rulison post-shot plans and evaluations are discussed and include physical characteristics of the Rulison cavity; pressure and temperature expected in the cavity; amount, nature, and distribution of radioactivity in the cavity; reentry plan; radioactive species which may be encountered during reentry; public safety considerations arising from release of radioactivity; procedures to assure public safety; and the radiological safety plan. Maximum hypothetical accidents and ecological considerations are discussed in the appendices.

  11. Zero-Shot Learning by Generating Pseudo Feature Representations

    OpenAIRE

    Lu, Jiang; Li, Jin; Yan, Ziang; Zhang, Changshui

    2017-01-01

    Zero-shot learning (ZSL) is a challenging task aiming at recognizing novel classes without any training instances. In this paper we present a simple but high-performance ZSL approach by generating pseudo feature representations (GPFR). Given the dataset of seen classes and side information of unseen classes (e.g. attributes), we synthesize feature-level pseudo representations for novel concepts, which allows us access to the formulation of unseen class predictor. Firstly we design a Joint Att...

  12. Why Some Pool Shots are More Difficult Than Others

    Indian Academy of Sciences (India)

    IAS Admin

    ical principles our treatment ignores the ball's spin, friction, and other well-known effects in the game of pool. Anyone who has ever played a game of pool, a form of billiards, is intuitively familiar with the following sce- nario: When a cue ball, an object ball, and a pocket lie more or less in a straight line (Figure 1a), the shot is.

  13. SnapShot: Hormones of the gastrointestinal tract.

    Science.gov (United States)

    Coate, Katie C; Kliewer, Steven A; Mangelsdorf, David J

    2014-12-04

    Specialized endocrine cells secrete a variety of peptide hormones all along the gastrointestinal (GI) tract, making it one of the largest endocrine organs in the body. Nutrients and developmental and neural cues trigger the secretion of gastrointestinal (GI) hormones from specialized endocrine cells along the GI tract. These hormones act in target tissues to facilitate digestion and regulate energy homeostasis. This SnapShot summarizes the production and functions of GI hormones. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Analysis and enhancement of 3D shape accuracy in a single-shot LIDAR sensor

    Science.gov (United States)

    Han, Munhyun; Choi, Gudong; Song, Minhyup; Seo, Hongseok; Mheen, Bongki

    2017-02-01

    The accuracy of timing jitter is of prime importance in the prevalent utilization of Light Detection and Ranging (LiDAR) technology for the real-time high-resolution three-dimensional (3D) image sensor, especially for relatively small object detection in various applications, such as in the fully automated car navigation and military surveillance. To assess the accuracy of timing, that is, the accuracy of the distance or three-dimensional shape, the standard deviation method can be used in the Time-of-Flight (ToF) LiDAR technology. While most timing jitter analyses are mainly based on a fiber-network or open space at a relatively short range distance, more accurate analyses are required to extract more information about the timing jitter at in a 3D image sensor long-range free space conditions for extended LiDAR-related applications. In this paper, utilizing a Single-Shot LiDAR System (SSLs) model with a 400 MHz wideband InGaAs Avalanche Photodiode and a 1550 nm 2 nsec full width at half maximum MOPA fiber laser, we analyzed the precise timing jitter for the implemented SSLs to characterize the measurement results. Additionally, we report the enhanced results for the resolution and precision in the given SSLs using the spline interpolation method from the measured results, and multiple-shot averaging (MSA). Finally, by adapting the proposed method to an implemented high resolution 3D LiDAR prototype, called the STUD LiDAR prototype, which can be understood as one kind of SSLs because it has a single source and a single detector as in a SSLs, we observed and analyzed the 3D resolution enhancement.

  15. Surface durability of powder-forged roller treated by shot peening

    International Nuclear Information System (INIS)

    Seki, Masanori; Fujii, Masahiro; Kobayashi, Yuji; Sato, Masaaki; Yoshida, Akira

    2010-01-01

    To investigate the influence of shot peening on the surface durability of powder-forged rollers, the case-hardened powder-forged rollers with a forging density of 7.5 g/cm 3 treated by the single shot peening and the double shot peening were fatigue-tested under a slidingrolling contact condition. The surface roughness, the surface hardness and the surface compressive residual stress of the rollers were increased by the shot peening. In addition, the pores near the roller surface were deformed by the shot peening. The failure mode of all the test rollers was spalling due to subsurface cracking. The fatigue lives of all the test rollers were improved by the shot peening, and that of the test roller S08, which was shot-peened with the hardest steel shots in this experimental range, was especially improved. The surface durability of the test roller S08 was also most improved by the shot peening. Cracks became difficult to occur and propagate under the roller surface since the pores near the roller surface were deformed by the stronger shot peening. In this study, double shot peening, which generally restrains the increase in surface roughness, was not particularly effective for the improvement in the surface durability of the powder-forged rollers, because the influence of tangential force on fatigue was not always great in a case of subsurface cracking

  16. Observability of radiation-pressure shot noise in optomechanical systems

    Science.gov (United States)

    Børkje, K.; Nunnenkamp, A.; Zwickl, B. M.; Yang, C.; Harris, J. G. E.; Girvin, S. M.

    2010-07-01

    We present a theoretical study of an experiment designed to detect radiation-pressure shot noise in an optomechanical system. Our model consists of a coherently driven optical cavity mode that is coupled to a mechanical oscillator. We examine the cross-correlation between two quadratures of the output field from the cavity. We determine under which circumstances radiation-pressure shot noise can be detected by a measurement of this cross-correlation. This is done in the general case of nonzero detuning between the frequency of the drive and the cavity resonance frequency. We study the qualitative features of the different contributions to the cross-correlator and provide quantitative figures of merit for the relative importance of the radiation-pressure shot noise contribution to other contributions. We also propose a modified setup of this experiment relevant to the “membrane-in-the-middle” geometry, which potentially can avoid the problems of static bistability and classical noise in the drive.

  17. First-time viewers' comprehension of films: bridging shot transitions.

    Science.gov (United States)

    Ildirar, Sermin; Schwan, Stephan

    2015-02-01

    Which perceptual and cognitive prerequisites must be met in order to be able to comprehend a film is still unresolved and a controversial issue. In order to gain some insights into this issue, our field experiment investigates how first-time adult viewers extract and integrate meaningful information across film cuts. Three major types of commonalities between adjacent shots were differentiated, which may help first-time viewers with bridging the shots: pictorial, causal, and conceptual. Twenty first-time, 20 low-experienced and 20 high-experienced viewers from Turkey were shown a set of short film clips containing these three kinds of commonalities. Film clips conformed also to the principles of continuity editing. Analyses of viewers' spontaneous interpretations show that first-time viewers indeed are able to notice basic pictorial (object identity), causal (chains of activity), as well as conceptual (links between gaze direction and object attention) commonalities between shots due to their close relationship with everyday perception and cognition. However, first-time viewers' comprehension of the commonalities is to a large degree fragile, indicating the lack of a basic notion of what constitutes a film. © 2014 The British Psychological Society.

  18. Transfer of mechanical energy during the shot put

    Directory of Open Access Journals (Sweden)

    Błażkiewicz Michalina

    2016-09-01

    Full Text Available The aim of this study was to analyse transfer of mechanical energy between body segments during the glide shot put. A group of eight elite throwers from the Polish National Team was analysed in the study. Motion analysis of each throw was recorded using an optoelectronic Vicon system composed of nine infrared camcorders and Kistler force plates. The power and energy were computed for the phase of final acceleration of the glide shot put. The data were normalized with respect to time using the algorithm of the fifth order spline and their values were interpolated with respect to the percentage of total time, assuming that the time of the final weight acceleration movement was different for each putter. Statistically significant transfer was found in the study group between the following segments: Right Knee – Right Hip (p = 0.0035, Left Hip - Torso (p = 0.0201, Torso – Right Shoulder (p = 0.0122 and Right Elbow – Right Wrist (p = 0.0001. Furthermore, the results of cluster analysis showed that the kinetic chain used during the final shot acceleration movement had two different models. Differences between the groups were revealed mainly in the energy generated by the hips and trunk.

  19. Laser desorption ionization and peptide sequencing on laser induced silicon microcolumn arrays

    Science.gov (United States)

    Vertes, Akos [Reston, VA; Chen, Yong [San Diego, CA

    2011-12-27

    The present invention provides a method of producing a laser-patterned silicon surface, especially silicon wafers for use in laser desorption ionization (LDI-MS) (including MALDI-MS and SELDI-MS), devices containing the same, and methods of testing samples employing the same. The surface is prepared by subjecting a silicon substrate to multiple laser shots from a high-power picosecond or femtosecond laser while in a processing environment, e.g., underwater, and generates a remarkable homogenous microcolumn array capable of providing an improved substrate for LDI-MS.

  20. X-ray emission from z pinches at 107 A: Current scaling, gap closure, and shot-to-shot fluctuations

    International Nuclear Information System (INIS)

    Stygar, W.A.; Ives, H.C.; Fehl, D.L.; Cuneo, M.E.; Mazarakis, M.G.; Bailey, J.E.; Bennett, G.R.; Bliss, D.E.; Chandler, G.A.; Leeper, R.J.; Matzen, M.K.; McDaniel, D.H.; McGurn, J.S.; McKenney, J.L.; Mix, L.P.; Muron, D.J.; Porter, J.L.; Ramirez, J.J.; Ruggles, L.E.; Seamen, J.F.

    2004-01-01

    We have measured the x-ray power and energy radiated by a tungsten-wire-array z pinch as a function of the peak pinch current and the width of the anode-cathode gap at the base of the pinch. The measurements were performed at 13- and 19-MA currents and 1-, 2-, 3-, and 4-mm gaps. The wire material, number of wires, wire-array diameter, wire-array length, wire-array-electrode design, normalized-pinch-current time history, implosion time, and diagnostic package were held constant for the experiments. To keep the implosion time constant, the mass of the array was increased as I 2 (i.e., the diameter of each wire was increased as I), where I is the peak pinch current. At 19 MA, the mass of the 300-wire 20-mm-diam 10-mm-length array was 5.9 mg. For the configuration studied, we find that to eliminate the effects of gap closure on the radiated energy, the width of the gap must be increased approximately as I. For shots unaffected by gap closure, we find that the peak radiated x-ray power P r ∝I 1.24±0.18 , the total radiated x-ray energy E r ∝I 1.73±0.18 , the x-ray-power rise time τ r ∝I 0.39±0.34 , and the x-ray-power pulse width τ w ∝I 0.45±0.17 . Calculations performed with a time-dependent model of an optically thick pinch at stagnation demonstrate that the internal energy and radiative opacity of the pinch are not responsible for the observed subquadratic power scaling. Heuristic wire-ablation arguments suggest that quadratic power scaling will be achieved if the implosion time τ i is scaled as I -1/3 . The measured 1σ shot-to-shot fluctuations in P r , E r , τ r , τ w , and τ i are approximately 12%, 9%, 26%, 9%, and 2%, respectively, assuming that the fluctuations are independent of I. These variations are for one-half of the pinch. If the half observed radiates in a manner that is statistically independent of the other half, the variations are a factor of 2 1/2 less for the entire pinch. We calculate the effect that shot-to-shot fluctuations of

  1. A Shot Parameter Specification Subsystem for automated control of PBFA [Particle Beam Fusion Accelerator] II accelerator shots

    International Nuclear Information System (INIS)

    Spiller, J.L.

    1987-01-01

    The Shot Parameter Specification Subsystem (SPSS) is an integral part of the automatic control system developed for the Particle Beam Fusion Accelerator II (PBFA II) by the Control Monitor (C/M) Software Development Team. This system has been designed to fully utilize the accelerator by tailoring shot parameters to the needs of the experimenters. The SPSS is the key to this flexibility. Automatic systems will be required on many pulsed power machines for the fastest turnaround, the highest reliability, and most cost effective operation. These systems will require the flexibility and the ease of use that is part of the SPSS. The PBFA II control system has proved to be an effective modular system, flexible enough to meet the demands of both the fast track construction of PBFA II and the control needs of Hermes III at the Simulation Technology Laboratory. This system is expected to meet the demands of most future machine changes

  2. Improved focal liver lesion detection: comparison of single-shot diffusion-weighted echoplanar and single-shot T-2 weighted turbo spin echo techniques

    NARCIS (Netherlands)

    Coenegrachts, K.; Delanote, J.; ter Beek, L.; Haspeslagh, M.; Bipat, S.; Stoker, J.; van Kerkhove, F.; Steyaert, L.; Rigauts, H.; Casselman, J. W.

    2007-01-01

    The purpose of this study was to compare diffusion-weighted respiratory-triggered single-shot spin echo echoplanar imaging (SS SE-EPI) sequence using four b-values (b=0, b=20, b=300, b=800 s mm(-2)) and single-shot T-2 weighted turbo spin echo (T2W SS TSE) in patients with focal liver lesions, with

  3. Effects of Rayleigh damping, friction and rate-dependency on 3D residual stress simulation of angled shot peening

    International Nuclear Information System (INIS)

    Kim, Taehyung; Lee, Hyungyil; Hyun, Hong Chul; Jung, Sunghwan

    2013-01-01

    Highlights: ► We propose a 3D FE model to study peening residual stress involving angled shots. ► The FE model set with plastic shot are found to best match the X-ray diffraction data. ► The model provides 3D multi-shot impact FE solution with various incidence angles. - Abstract: In this study, we propose a 3D finite element (FE) model to study shot peening involving angled shots. Using the FE model for angled shot peening, we examine relationships with the residual stress introduced by shot peening of the factors such as the Rayleigh damping in the material, dynamic friction, and the rate dependency of the material and systematically integrate them with the FE model. The FE model is set with rigid shot, elastic shot, and plastic shot respectively. Plastic deformation of the shot is also explored with the FE model. The FE model is applied to study angled multi-shots. The FE results are verified with experimental data using X-ray diffraction (XRD). The FE model set with plastic shot are found to best match the XRD results validating accuracy of the 3D FE model properly integrated with the factors and plastically deformable shot ball. The proposed model will serve to simulate actual shot peening cases, which generally involve multi-shots with various incidence angles

  4. The single-shot opto-digitizer; L'optoechantillonneur monocoup

    Energy Technology Data Exchange (ETDEWEB)

    Nail, M.; Gibert, Ph. [CEA/DAM-Ile de France, Dept. de Conception et Realisation des Experimentations (DCRE), 91 - Bruyeres-le-Chatel (France); CEA/DAM-Ile de France, Dept. Laser Puissance, DLP, 91 - Bruyeres-Le-Chatel (France)

    2000-07-01

    Laser-plasma experiments need to measure signals provided either by X-ray, photonic or neutronic detector. The measurement should have 50 GHz bandwidth and up to several hundred of Giga-Hertz for sub picosecond plasmas. For this purpose, a 35 GHz single shot opto-digitizer (10 ps risetime) has been studied and built. The device is made up of a 50 ohms microstrip propagation line, periodically lined by 100 sampled gates. The propagation line is long enough to measure a 400 ps duration. The sampling rate is 250 Gsa/s (every 4 ps). The sampled gates are made with fast recombining photo-material and turn on by a subpicosecond laser pulse which is synchronized exactly with the analysed phenomena. Every gate is recording to a storing capacitor. After the recording, every capacitor charge is needed to built the signal that was displayed on the propagation line. The dynamic range of measurement is 47 for the entire device. The device can measure positive or negative signals from 1.5 to 70 Volts. To increase the bandwidth, two another kinds of opto-digitizer were studied: one is a buried stripline with 56 GHz band width, the other a 70 GHz coplanar transmission line. For the purpose of subpicosecond plasmas, a 30 coplanar waveguide opto-digitizer was studied. Characteristics are as followed: window of measurement 40 ps, sampling rate 1 ps, bandwidth 230 GHz. Finally, a bundle of optical fibers was used to propagate the laser beam on semiconductor gates. If the gates are lighted at the same time, i.e. if the optical fibers have the same length, we get a simultaneous addressing. By using different lengths of optical fibers, we can do a sequential addressing. So, the sampling rate becomes a combination of the distance between two adjacent sampled channels, and the difference in length of optical fibers. (author)

  5. Summary Report of Working Group 6: Laser-Plasma Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Leemans, Wim P.; Downer, Michael; Siders, Craig

    2006-07-01

    A summary is given of presentations and discussions in theLaser-Plasma Acceleration Working Group at the 2006 Advanced AcceleratorConcepts Workshop. Presentation highlights include: widespreadobservation of quasi-monoenergetic electrons; good agreement betweenmeasured and simulated beam properties; the first demonstration oflaser-plasma acceleration up to 1 GeV; single-shot visualization of laserwakefield structure; new methods for measuring<100 fs electronbunches; and new methods for "machining" laser-plasma acceleratorstructures. Discussion of future direction includes: developing a roadmapfor laser-plasma acceleration beyond 1 GeV; a debate over injection andguiding; benchmarking simulations with improved wake diagnostics;petawatt laser technology for future laser-plasmaaccelerators.

  6. Electromagnetic pulses generated by high-power laser experiments

    International Nuclear Information System (INIS)

    Lubrano-Lavaderci, F.; Dubois, J.L.; Gazave, J.; Raffestin, D.; Bazzoli, S.

    2013-01-01

    During high-power laser experiments, intense electromagnetic fields are produced. For future facilities, the field level is extrapolated from measurements performed on current experimental rooms. In the LMJ (Laser Mega Joule) target chamber with the high-power PETAL beam (Petawatt Aquitaine Laser), the expected field is about 1 MW/m for high laser intensity shots (higher than 10 19 W/cm 2 ). This is a harsh environment for electric equipments. For these short-pulse laser experiments, simulations show that electromagnetic pulses are due to charged particles emission during the shot, more exactly they are due to the resulting replacement currents that appear in the target chamber. This paper shows a simulation (with the numerical tool SOPHIE) of this phenomenon, in good agreement with experimental data from Titan and Omega-EP facilities. (authors)

  7. Contribution to the development of numerical tools for the hardening of electronic devices to the neutronic and electromagnetic environment induced by a high power gain shot; Contribution a la mise en oeuvre de moyens de simulation numerique pour l'etude de la vulnerabilite des systemes electriques soumis a l'environnement radiatif et electromagnetique du Laser Megajoule

    Energy Technology Data Exchange (ETDEWEB)

    Gazave, J

    2007-12-15

    When fusion ignition will be attained inside the target chambers of high energy laser facilities (LMJ-France and NIF-Usa), a harsh environment, composed of nuclear particles and an electromagnetic pulse (EMP) will be induced. All electronic devices located in the vicinity will be sensitive to this environment. In the first part of this work, a simulation method has been developed to evaluate transient currents that will be induced in coaxial cables. The relevance of this model is then discussed thanks to comparisons with experimental results. In a second part, the possibility to simulate the propagation of the EMP, inside and outside such a big structure as a target chamber, using the finite difference in time and domain (FDTD) method is evaluated. The use of a classic FDTD method is impossible for this kind of simulation because of the huge computer resources needed. It is the reason why a 3-dimensional space-time sub-grid method for FDTD has been developed and some massively parallel FDTD calculations have also been performed. (author)

  8. Methodology for calculating guideline concentrations for safety shot sites

    International Nuclear Information System (INIS)

    1997-06-01

    Residual plutonium (Pu), with trace quantities of depleted uranium (DU) or weapons grade uranium (WU), exists in surficial soils at the Nevada Test Site (NTS), Nellis Air Force Range (NAFR), and the Tonopah Test Range (TTR) as the result of the above-ground testing of nuclear weapons and special experiments involving the detonation of plutonium-bearing devices. The special experiments (referred to as safety shots) involving plutonium-bearing devices were conducted to study the behavior of Pu as it was being explosively compressed; ensure that the accidental detonation of the chemical explosive in a production weapon would not result in criticality; evaluate the ability of personnel to manage large-scale Pu dispersal accidents; and develop criteria for transportation and storage of nuclear weapons. These sites do not pose a health threat to either workers or the general public because they are under active institutional control. The DOE is committed to remediating the safety shot sites so that radiation exposure to the public, both now and in the future, will be maintained within the established limits and be as low as reasonably achievable. Remediation requires calculation of a guideline concentration for the Pu, U, and their decay products that are present in the surface soil. This document presents the methodology for calculating guideline concentrations of weapons grade plutonium, weapons grade uranium, and depleted uranium in surface soils at the safety shot sites. Emphasis is placed on obtaining site-specific data for use in calculating dose to potential residents from the residual soil contamination

  9. Methodology for calculating guideline concentrations for safety shot sites

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    Residual plutonium (Pu), with trace quantities of depleted uranium (DU) or weapons grade uranium (WU), exists in surficial soils at the Nevada Test Site (NTS), Nellis Air Force Range (NAFR), and the Tonopah Test Range (TTR) as the result of the above-ground testing of nuclear weapons and special experiments involving the detonation of plutonium-bearing devices. The special experiments (referred to as safety shots) involving plutonium-bearing devices were conducted to study the behavior of Pu as it was being explosively compressed; ensure that the accidental detonation of the chemical explosive in a production weapon would not result in criticality; evaluate the ability of personnel to manage large-scale Pu dispersal accidents; and develop criteria for transportation and storage of nuclear weapons. These sites do not pose a health threat to either workers or the general public because they are under active institutional control. The DOE is committed to remediating the safety shot sites so that radiation exposure to the public, both now and in the future, will be maintained within the established limits and be as low as reasonably achievable. Remediation requires calculation of a guideline concentration for the Pu, U, and their decay products that are present in the surface soil. This document presents the methodology for calculating guideline concentrations of weapons grade plutonium, weapons grade uranium, and depleted uranium in surface soils at the safety shot sites. Emphasis is placed on obtaining site-specific data for use in calculating dose to potential residents from the residual soil contamination.

  10. One-shot service searches: Preprint repositories at a mouseclick

    International Nuclear Information System (INIS)

    Canessa, E.; Pastore, G.

    1996-09-01

    In this article we introduce the ICTP-International Centre for Theoretical Physics's prototype for a ''One-Shot World-Wide Preprints Search'' on the Web. This is a new centralized interface for a global search throughout the most popular scientific preprint repositories. Herein, we briefly discuss our experience with the implementation of this service and propose it as a possible alternative solution to the problem of getting access to the information without being either overloaded with lots of new documents or not being informed at all. (author). 13 refs, 3 figs

  11. INFLUENCE OF SHOT PEENING ON AISI 316Ti FATIGUE PROPERTIES

    Directory of Open Access Journals (Sweden)

    Mario Guagliano

    2012-05-01

    Full Text Available This paper deals with examination of fatigue properties of AISI 316Ti stainless steel before and after shot peening including analysis of residual stress relaxation during rotating bending fatigue tests (f = 50 Hz, T = 20 ± 3 °C, R = - 1 with use of X - ray diffractometer. Obtained experimental results show increase of fatigue properties in the high – cycle region including fatigue limit and show the behavior of residual stress, decrease, at given cyclic loading amplitude in the region from N = 103 cycles to N = 107 cycles of loading.

  12. The example of the UK SHOT haemovigilance system

    Directory of Open Access Journals (Sweden)

    Perla Eleftheriou

    2014-12-01

    Full Text Available SHOT (Serious Hazards of Transfusion scheme is the UK’s National confidential haemovigilance system, and was set up in 1996. It is an independent, confidential, professionally led haemovigilance scheme. Initially the reporting was voluntary but now required by several professional bodies. SHOT publishes annual reports with recommendations and circulates to all relevant organizations including the 4 UK Blood services, Departments of Health in England, Wales, Scotland and Northern Ireland, all relevant professional bodies and reporting hospitals. Over the 17 years of reporting, the evidence gathered has prompted changes in transfusion practice from the selection and management of donors to changes in hospital practice, better education and training. Acute transfusion reactions and transfusion-associated circulatory overload carry the highest risk for morbidity and death. Greatest risk to patients remain errors in the process at the point of blood sampling, in the laboratory and at bedside administration. SHOT’s objectives are to use findings to improve standards of hospital transfusion practice, to educate users on transfusion hazards and prevention, to aid production of clinical guidelines in blood transfusion and to inform national policy on transfusion safety. MHRA is the UK competent authority to which serious adverse reactions and events have to be reported annually. Overall the most common adverse incidents are caused by errors, resulting in the transfusion of an incorrect component or one that does not meet the specific requirements of the patient (e.g. not irradiated or not appropriately antigen matched. TACO (transfusion associated circulatory overload accounts for most deaths and major morbidity reported to SHOT but is overall underreported. Transfusions are not always given appropriately. This may be due to wrong haemoglobin results, failure to assess patients appropriately, or avoidable use of emergency O RhD negative units because

  13. A frequency-domain derivation of shot-noise

    Science.gov (United States)

    Rice, Frank

    2016-01-01

    A formula for shot-noise is derived in the frequency-domain. The derivation is complete and reasonably rigorous while being appropriate for undergraduate students; it models a sequence of random pulses using Fourier sine and cosine series, and requires some basic statistical concepts. The text here may serve as a pedagogic introduction to the spectral analysis of random processes and may prove useful to introduce students to the logic behind stochastic problems. The concepts of noise power spectral density and equivalent noise bandwidth are introduced.

  14. Micro-MID Manufacturing By Two-Shot Injection Moulding

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2008-01-01

    a specific MID process chain is used for micro products, many technical challenges are encountered which would not be problems for macro scale products. This paper investigates on a specific MID process chain (two shot moulding) and discusses the technical difficulties associated with the production process...... when the production shifts from macro to micro scale products. The investigation shows that some of the materials which are suitable for macro MIDs are not suitable for micro MIDs. Polymer-polymer bond strength, interface between two polymers and interface metallization of polymers are critical...

  15. Lasers As Particle Accelerators In Medicine: From Laser-Driven Protons To Imaging With Thomson Sources

    Science.gov (United States)

    Pogorelsky, I. V.; Babzien, M.; Polyanskiy, M. N.; Yakimenko, V.; Dover, N. P.; Palmer, C. A. J.; Najmudin, Z.; Shkolnikov, P.; Williams, O.; Rosenzweig, J.; Oliva, P.; Carpinelli, M.; Golosio, B.; Delogu, P.; Stefanini, A.; Endrizzi, M.

    2011-06-01

    We report our recent progress using a high-power, picosecond CO2 laser for Thomson scattering and ion acceleration experiments. These experiments capitalize on certain advantages of long-wavelength CO2 lasers, such as their high number of photons per energy unit and beneficial wavelength- scaling of the electrons' ponderomotive energy and critical plasma frequency. High X-ray fluxes produced in the interactions of the counter-propagating laser- and electron-beams for obtaining single-shot, high-contrast images of biological objects. The laser, focused on a hydrogen jet, generated a monoenergetic proton beam via the radiation-pressure mechanism. The energy of protons produced by this method scales linearly with the laser's intensity. We present a plan for scaling the process into the range of 100-MeV proton energy via upgrading the CO2 laser. This development will enable an advance to the laser-driven proton cancer therapy.

  16. Enhancement of the shot noise of a quantum dot–Luttinger lead system

    International Nuclear Information System (INIS)

    Yang, Kai-Hua; Liu, Bei-Yun; Wang, Huai-Yu; He, Xian

    2013-01-01

    We investigate the joint effects of the intralead electron interaction and Coulombic dot–lead interaction on the shot noise of a quantum dot coupled to Luttinger liquid leads. A formula of the shot noise is derived by applying the nonequilibrium Green function technique. The shot noise is enhanced by the dot–lead interaction. For a weak or moderately strong interaction the differential shot noise demonstrates resonant-like behavior as a function of bias and gate voltages. In the limit of strong interaction resonant behavior disappears and the differential shot noise and Fano factor scale as a power law in bias voltage. Under some parameters, the differential shot noise may become negative around resonant peaks, and the physical reason is analyzed.

  17. Effect of shot peening on crack growth resistance in corrosion environment

    International Nuclear Information System (INIS)

    Jin, Young Beom; Park, Keyung Dong

    2005-01-01

    Antifatigue failure technology take an important the part of current industries. Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefore in this paper the effect of compressive residual stress by shot peening on fatigue crack growth characteristics in stress ratio(R=0.05)was investigated with considering fracture mechanics. There is difference between shot peening specimen and unpeening specimen. Fatigue crack growth rate of shot peening specimen was lower than that of unpeening. Fatigue life shows more improvement in the shot peening material than in the unpeening material. And compressive residual stress of surface on the shot peening process operate resistance force of fatigue propagation

  18. The finite element analysis for prediction of residual stresses induced by shot peening

    International Nuclear Information System (INIS)

    Kim, Cheol; Yang, Won Ho; Sung, Ki Deug; Cho, Myoung Rae; Ko, Myung Hoon

    2000-01-01

    The shot peening is largely used for a surface treatment in which small spherical parts called shots are blasted on a surface of a metallic components with velocities up to 100m/s. This treatment leads to an improvement of fatigue behavior due to the developed compressive residual stresses, and so it has gained widespread acceptance in the automobile and aerospace industries. The residual stress profile on surface layer depends on the parameters of shot peening, which are, shot velocity, shot diameter, coverage, impact angle, material properties etc. and the method to confirm this profile is only measurement by X-ray diffractometer. Despite its importance to automobile and aerospace industries, little attention has been devoted to the accurate modeling of the process. In this paper, the simulation technique is applied to predict the magnitude and distribution of the residual stress and plastic deformation caused by shot peening with the help of the finite element analysis

  19. Lead shot ingestion in two raptor species from Doñana, Spain.

    Science.gov (United States)

    Mateo, R; Cadenas, R; Máñez, M; Guitart, R

    2001-01-01

    Diurnal raptors inhabiting wetland areas where waterfowl shooting is conducted have many opportunities to ingest lead (Pb) shot pellets when feeding on their prey. Exposure to Pb shot was studied in the Spanish imperial eagle (Aquila adalberti), an endangered species with a world population of about 150 breeding pairs, and in the red kite (Milvus milvus) from Doñana (southwest Spain). Lead exposure was evaluated by the presence of Pb shot in the pellets of both species. Results obtained by this noninvasive method demonstrated Pb shot in 11.0% of Spanish imperial eagle and 5.5% of red kite pellets. When the data of both species were pooled, there was a significant relationship between Pb shot ingestion and consumption of waterfowl during the hunting season. Pb shot found in pellets exhibited signs of erosion, and their weight distribution had peaks at 70, 170, and 240 mg, which could correspond to ammunition used for duck and goose hunting.

  20. Technical description of the PHEBUS laser

    International Nuclear Information System (INIS)

    1987-12-01

    The PHEBUS installation for laser-fusion activities consists of a laser composed of two power assemblies of neodymium doped glass, of 74 cm final diameter, capable of producing an output energy of the order of 20 kJ at 1.05 microns and 10 kJ at 0.35 or 0.53 microns for pulse durations of 1 to 6 nanosec. The laser alignment and diagnostics devices assure correct focusing of the beam on the target enable the functioning of the laser and the energy focused at each shot to be characterised. The laser beams are focused onto a target in the middle of an experiment chamber in which all the systems for diagnosing the plasma created during the interaction are coupled. A third laser system, of reduced power, is used essentially for X diagnostics of the plasma. A computerized command-control system controls the overall operation of the installation [fr

  1. Single-shot observation of growing streamers using an ultrafast camera

    International Nuclear Information System (INIS)

    Takahashi, E; Kato, S; Furutani, H; Sasaki, A; Kishimoto, Y; Takada, K; Matsumura, S; Sasaki, H

    2011-01-01

    A recently developed ultrafast camera that can acquire 10 8 frames per second was used to investigate positive streamer discharge. It enabled single-shot evaluation of streamer evolution without the need to consider shot-to-shot reproducibility. This camera was used to investigate streamers in argon. Growing branches, the transition when a streamer forms a return stroke, and related phenomena were clearly observed. (fast track communication)

  2. Temperature dependence of shot noise in double barrier magnetic tunnel junctions

    Science.gov (United States)

    Niu, Jiasen; Liu, Liang; Feng, J. F.; Han, X. F.; Coey, J. M. D.; Zhang, X.-G.; Wei, Jian

    2018-03-01

    Shot noise reveals spin dependent transport properties in a magnetic tunnel junction. We report measurement of shot noise in CoFeB/MgO/CoFeB/MgO/CoFeB double barrier magnetic tunnel junctions, which shows a strong temperature dependence. The Fano factor used to characterize shot noise increases with decreasing temperature. A sequential tunneling model can be used to account for these results, in which a larger Fano factor results from larger spin relaxation length at lower temperatures.

  3. Submicrometre periodic surface structures in InP induced by nanosecond UV laser pulses

    International Nuclear Information System (INIS)

    Kumar, Brijesh; Soni, R K

    2008-01-01

    We report fabrication of submicrometre size laser-induced periodic surface structures (ripples) on single crystalline InP by nanosecond (ns) pulsed Nd : YAG laser beam irradiation of fourth harmonic wavelength (266 nm) in HF electrolyte. The ripples are orientated parallel to the laser polarization direction and power spectral density analysis reveals reduction in the spatial period of the ripples with increasing number of laser shots. The formation of periodic structures in the presence of electrolyte is empirically explained on the basis of photoelectrochemical etching and variation of periodicity with refractive index change on laser energy and number of laser pulses. From the analysis of energy dispersive x-ray, photoluminescence (PL) and micro-Raman spectroscopy measurements on the rippled surface we conclude that the ripple structures are capped with a thin layer of In 2 O 3 . Further, a blue shift of 0.328 eV compared with the band-edge luminescence of InP is estimated from the PL spectrum of the structure fabricated with 200 laser shots. The blue shift of the PL peak is attributed to the quantum confinement effect in the nanometre size structures in the rippled surface. Micro-Raman spectra show good crystalline quality of the surface at lower number of laser shots and its degradation caused by oxidation at the higher number of shots

  4. Resonant holographic measurements of laser ablation plume expansion in vacuum and argon gas backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Lindley, Roger Alan [Michigan Univ., Ann Arbor, MI (United States)

    1993-01-01

    This thesis discusses the following on resonant holographic measurements of laser ablation plume expansion: Introduction to laser ablation; applications of laser ablation; The study of plume expansion; holographic interferometry; resonant holographic interferometry; accounting for finite laser bandwidth; The solution for doppler broadening and finite bandwidth; the main optical table; the lumonics laser spot shape; developing and reconstructing the holograms; plume expansion in RF/Plasma Environments; Determining λ°; resonant refraction effects; fringe shift interpretation; shot-to-shot consistency; laser ablation in vacuum and low pressure, inert, background gas; theoretically modeling plume expansion in vacuum and low pressure, inert, background gas; and laser ablation in higher pressure, inert, background gas.

  5. Effects of shot peening on the friction and wear of a metallic material

    International Nuclear Information System (INIS)

    Kim, Joo Young; Kim, Tae Hyung; Cheong, Seong Kyun

    2002-01-01

    This paper investigates the characteristics of friction and wear of shot peened AI 7075. Three types of specimens were used to get the experimental results. One type of specimen was made by machining and polishing. Another type of specimen was made by machining, shot peening. The other type of specimen was made by machining, shot peening, and polishing. TE77(PLINT) friction and wear tester was used to obtain the experimental data under 100N and 3Hz. The experimental results show that the shot peening process enhances the hardness near the surface of specimens and improves the wear resistance

  6. Development of a shot-blasting robot for removal of the wall concrete surface

    International Nuclear Information System (INIS)

    Tokioka, Seigo; Inagaki, Hiroichi; Sakai, Sachio; Kasahara, Ichirou; Ishigami, Shinya

    1991-01-01

    This paper reports research and development of a shot-blasting robot, for which the following targets are set up and their performances confirmed through basic experiments: (1) Uniform removal of concrete surface by an impeller type shot-blasting system. (2) Recycling of projecting material (steel shot). (3) Separation of removal material. And on the basis of these, its application to decontamination of nuclear power facilities is projected. The following three problems were focused on and the results of study are reported as follows: Step 1 : As part of a mechanical basic test, a manual type shot-blasting unit was mounted on a test device which may move freely on the concrete, and its data concerning finishing performance was obtained. Step 2 : On the basis of the results of the mechanization basic test, remote controlling of the shot blasting unit and its mounting on the suction type self-climbing carriage were studied first, secondly data of shot-blasting, operation and control method was gathered to develop a shot-blasting robot. Step 3 : A shot-blasting test was conducted for confirming climbing and shot-blasting performances. (author)

  7. The shot noise of a strongly correlated quantum dot coupled to the Luttinger liquid leads

    International Nuclear Information System (INIS)

    Yang, Kai-Hua; He, Xian; Wang, Huai-Yu; Liu, Kai-Di; Liu, Bei-Yun

    2014-01-01

    We study the shot noise of a strongly correlated quantum dot weakly coupled to Luttinger liquid leads in the Kondo regime by means of the extended equation of motion method. A general zero-frequency shot noise formula with good convergence is derived. The shot noise exhibits a non-monotonic dependence on voltage for weak intralead interaction. There is a peak around the Kondo temperature at low voltage when the interaction is very weak, and its height decreases rapidly with the intralead interaction increasing. When the interaction is moderately strong the peak disappears and the shot noise scales as a power law in bias voltage, indicating that the intralead electron interaction suppresses the shot noise. It is possible that the measurements of the shot noise spectrum can extract the information of the intralead interaction. - Highlights: • The shot noise of a dot coupled to Luttinger liquid leads in the Kondo regime. • A shot noise formula is derived. • Intralead interaction suppresses the shot noise. • The noise shows different voltage-dependence for different intralead interaction

  8. Study on the use of types of shots in Valencian Handball on professional players

    Directory of Open Access Journals (Sweden)

    José Antonio Martínez Carbonell

    2013-01-01

    Full Text Available Due to the shortage of studies of analysis in Valencian ball, we have centred this study on this sport. The aim of study has been to analyze and to quantify the types of shots , and to compare the same ones between the positions of game of 1st game line (resto and 2nd game line (medio. Analysis of 6 games of the 19th Professional League of Stand and rope 2009-2010 was carried out so i, and specifically of 12 players, using Sports Code analysis software. The results indicate significant differences (p<0.05 between the shots carried out by first game line player and second game line in the rebound and rebound-shot all of them of right and left hand,and stand shot right hand; being almost realitzados only by players from the first game line position. At the same time we find data which demonstrate us by another band used mainly by second game line players beatings, these have been volley shot, volley shot after bounce, volley shot under the line of the shoulders, palm shot and horizontal shot all of them of right hand. As conclusion of the study, we have obtained that depending on the position of game the players use a few types of I throb or others. Therefore, we affirm, that the analysis of the high performance in stand and rope from the advances of the technologies, a valuable information contributes us to establish specific bosses of training.

  9. A study on corrosive behavior of spring steel by shot-peening process

    International Nuclear Information System (INIS)

    An, Jae Pil; Park, Keyung Dong

    2004-01-01

    In this study, the influence of shot peening on the corrosion was investigated on spring steel immersed in 3.5% NaCl. The immersion test was performed on the two kinds of specimens. Corrosion potential, polarization curve, residual stress and etc. were investigated from experimental results. From test results, the effect of shot peening on the corrosion was evaluated. In case of corrosion potential, shot peened specimen shows more activated negative direction as compared with parent metal. Surface of specimen, which is treated with the shot peened, is placed as more activated state against inner base metal. It can cause the anti-corrosion effect on the base metal

  10. Muscular power, neuromuscular activation, and performance in shot put athletes at preseason and at competition period.

    Science.gov (United States)

    Kyriazis, Thomas A; Terzis, Gerasimos; Boudolos, Konstantinos; Georgiadis, Georgios

    2009-09-01

    The aim of this study was to investigate changes in shot put performance, muscular power, and neuromuscular activation of the lower extremities, between the preseason and the competition period, in skilled shot put athletes using the rotational technique. Shot put performance was assessed at the start of the pre-season period as well as after 12 weeks, at the competition period, in nine shot putters. Electromyographic (EMG) activity of the right vastus lateralis muscle was recorded during all shot put trials. Maximum squat strength (1RM) and mechanical parameters during the countermovement jump (CMJ) on a force platform were also determined at pre-season and at competition period. Shot put performance increased 4.7% (p Shot put performance was significantly related with muscular power and takeoff velocity during the CMJ, at competition period (r = 0.66, p shot put performance. These results suggest that muscular power of the lower extremities is a better predictor of rotational shot put performance than absolute muscular strength in skilled athletes, at least during the competition period.

  11. Relative toxicity of lead and selected substitute shot types to game farm mallards

    Science.gov (United States)

    Irby, H.D.; Locke, L.N.; Bagley, George E.

    1967-01-01

    The acute toxicity of lead, three types of plastic-coated lead, two lead-magnesium alloys, iron, copper, zinc-coated iron, and molybdenum-coated iron shot were tested in year-old male game farm mallards. Mallards (Anus platyrhynchos) were fed eight number 6 shot of each type and observed for a period of 60 days. Ducks used totaled 230 and most shot types were tested in three replicates of 8 ducks each. Mortality and losses of body weight were the criteria used for judging toxicity. Three types of plastic-coated lead shot were as toxic (93 percent) as the commercial lead shot (96 percent). The average mortality in mallards fed lead-magnesium alloy shot was less (58 percent) than that occurring in birds fed commercial lead shot. Mortality among mallards fed iron, copper, zinc-coated iron or molybdenum-coated iron shot was significantly less than in birds fed lead shot, and was not significantly greater than the conrtols.

  12. The Numerical FEM Model of the Kinematics of the Vibratory Shot Peening Process

    Directory of Open Access Journals (Sweden)

    Stanisław Bławucki

    2017-12-01

    Full Text Available The paper presents the results of numerical calculations, with the finite element method in the ABAQUS program environment, of the vibratory shot peening process with loose peening elements. The behaviour of shot peening elements was analysed in the kinematic aspect. The impact of the initial deployment of vibratory shot peening elements on their behaviour during processing was investigated, including the displacement, velocity, acceleration and the number of collisions. The way of determining the effectiveness of the processing with the vibratory shot peening was illustrated.

  13. A Genetic Algorithm and Fuzzy Logic Approach for Video Shot Boundary Detection.

    Science.gov (United States)

    Thounaojam, Dalton Meitei; Khelchandra, Thongam; Manglem Singh, Kh; Roy, Sudipta

    2016-01-01

    This paper proposed a shot boundary detection approach using Genetic Algorithm and Fuzzy Logic. In this, the membership functions of the fuzzy system are calculated using Genetic Algorithm by taking preobserved actual values for shot boundaries. The classification of the types of shot transitions is done by the fuzzy system. Experimental results show that the accuracy of the shot boundary detection increases with the increase in iterations or generations of the GA optimization process. The proposed system is compared to latest techniques and yields better result in terms of F1score parameter.

  14. Coherent-light-boosted, sub-shot noise, quantum interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Plick, William N; Dowling, Jonathan P [Hearne Institute for Theoretical Physics, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Agarwal, Girish S, E-mail: bplick@yahoo.co [Department of Physics, Oklahoma State University, Stillwater, OK 74078 (United States)

    2010-08-15

    We present in this paper a new scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the potential to reach far below the shot-noise limit in phase sensitivity. This new proposal avoids the pitfalls of other setups, such as difficulty in creating the required resource. Furthermore, our scheme requires no complicated detection protocol, relying instead only on simple intensity measurement. Also, bright, coherent sources 'boost' squeezed light, creating a very sensitive device. This hybrid scheme relies on no unknown components and can be constructed with current technology. In this paper, we present our analysis of this relatively straightforward device, using the operator propagation method. We derive the phase sensitivity and provide a simple numerical example of the power of our new proposal. Sensitivity to unknown phase shifts scales as a shot-noise-limited Mach-Zehnder interferometer, multiplied by a sub-Heisenberg contribution from the squeezed light.

  15. Coherent-light-boosted, sub-shot noise, quantum interferometry

    International Nuclear Information System (INIS)

    Plick, William N; Dowling, Jonathan P; Agarwal, Girish S

    2010-01-01

    We present in this paper a new scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the potential to reach far below the shot-noise limit in phase sensitivity. This new proposal avoids the pitfalls of other setups, such as difficulty in creating the required resource. Furthermore, our scheme requires no complicated detection protocol, relying instead only on simple intensity measurement. Also, bright, coherent sources 'boost' squeezed light, creating a very sensitive device. This hybrid scheme relies on no unknown components and can be constructed with current technology. In this paper, we present our analysis of this relatively straightforward device, using the operator propagation method. We derive the phase sensitivity and provide a simple numerical example of the power of our new proposal. Sensitivity to unknown phase shifts scales as a shot-noise-limited Mach-Zehnder interferometer, multiplied by a sub-Heisenberg contribution from the squeezed light.

  16. Caffeine Content in Popular Energy Drinks and Energy Shots.

    Science.gov (United States)

    Attipoe, Selasi; Leggit, Jeffrey; Deuster, Patricia A

    2016-09-01

    The use of energy beverages is high among the general population and military personnel. Previous studies have reported discrepancies between the actual amount of caffeine in products and the amount of caffeine on stated labels. Thus, the purpose of this study was to examine the content of caffeine listed on the labels of various energy drinks and energy shots. Top-selling energy drinks (n = 9) and energy shots (n = 5) were purchased from retail stores. Three of each of the 14 products were purchased and analyzed for caffeine content by an independent laboratory. Of the 14 products tested, 5 did not provide caffeine amounts on their facts panel-of those, 3 listed caffeine as an ingredient and 2 listed caffeine as part of a proprietary blend. The remaining 9 (of 14) products stated the amounts of caffeine on their labels, all of which were within 15% of the amount indicated on the label. In this study, although the energy beverages that indicated the amount of caffeine it contained had values within ±15% of the amount listed on the label, a potentially acceptable range, this finding is not acceptable with regard to current labeling regulations, which require added ingredients to total 100%. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

  17. Single-shot work extraction in quantum thermodynamics revisited

    Science.gov (United States)

    Wang, Shang-Yung

    2018-01-01

    We revisit the problem of work extraction from a system in contact with a heat bath to a work storage system, and the reverse problem of state formation from a thermal system state in single-shot quantum thermodynamics. A physically intuitive and mathematically simple approach using only elementary majorization theory and matrix analysis is developed, and a graphical interpretation of the maximum extractable work, minimum work cost of formation, and corresponding single-shot free energies is presented. This approach provides a bridge between two previous methods based respectively on the concept of thermomajorization and a comparison of subspace dimensions. In addition, a conceptual inconsistency with regard to general work extraction involving transitions between multiple energy levels of the work storage system is clarified and resolved. It is shown that an additional contribution to the maximum extractable work in those general cases should be interpreted not as work extracted from the system, but as heat transferred from the heat bath. Indeed, the additional contribution is an artifact of a work storage system (essentially a suspended ‘weight’ that can be raised or lowered) that does not truly distinguish work from heat. The result calls into question the common concept that a work storage system in quantum thermodynamics is simply the quantum version of a suspended weight in classical thermodynamics.

  18. Few-shot learning in deep networks through global prototyping.

    Science.gov (United States)

    Blaes, Sebastian; Burwick, Thomas

    2017-10-01

    Training a deep convolution neural network (CNN) to succeed in visual object classification usually requires a great number of examples. Here, starting from such a pre-learned CNN, we study the task of extending the network to classify additional categories on the basis of only few examples ("few-shot learning"). We find that a simple and fast prototype-based learning procedure in the global feature layers ("Global Prototype Learning", GPL) leads to some remarkably good classification results for a large portion of the new classes. It requires only up to ten examples for the new classes to reach a plateau in performance. To understand this few-shot learning performance resulting from GPL as well as the performance of the original network, we use the t-SNE method (Maaten and Hinton, 2008) to visualize clusters of object category examples. This reveals the strong connection between classification performance and data distribution and explains why some new categories only need few examples for learning while others resist good classification results even when trained with many more examples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The Study of Advanced Accelerator Physics Research at UCLA Using the ATF at BNL: Vacuum Acceleration by Laser of Free Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Cline, David B. [Univ. of California, Los Angeles, CA (United States)

    2016-09-07

    An experiment was designed and data were taken to demonstrate that a tightly focused laser on vacuum can accelerate an electron beam in free space. The experiment was proof-of-principle and showed a clear effect for the laser beam off and on. The size of the effect was about 20% and was consistent over 30 laser and beam shots.

  20. Single shot imaging through turbid medium and around corner using coherent light

    Science.gov (United States)

    Li, Guowei; Li, Dayan; Situ, Guohai

    2018-01-01

    Optical imaging through turbid media and around corner is a difficult challenge. Even a very thin layer of a turbid media, which randomly scatters the probe light, can appear opaque and hide any objects behind it. Despite many recent advances, no current method can image the object behind turbid media with single record using coherent laser illumination. Here we report a method that allows non-invasive single-shot optical imaging through turbid media and around corner via speckle correlation. Instead of being as an obstacle in forming diffractionlimited images, speckle actually can be a carrier that encodes sufficient information to imaging through visually opaque layers. Optical imaging through turbid media and around corner is experimentally demonstrated using traditional imaging system with the aid of iterative phase retrieval algorithm. Our method require neither scan of illumination nor two-arm interferometry or long-time exposure in acquisition, which has new implications in optical sensing through common obscurants such as fog, smoke and haze.

  1. Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy.

    Science.gov (United States)

    Kojima, Sadaoki; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Ozaki, Tetsuo; Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori; Fujioka, Shinsuke; Azechi, Hiroshi

    2016-04-01

    Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10(13) photons/shot) hard X-rays. However, high energy resolution (Δhv/hv spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO2 converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

  2. Single-shot mega-electronvolt ultrafast electron diffraction for structure dynamic studies of warm dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Mo, M. Z., E-mail: mmo09@slac.stanford.edu; Shen, X.; Chen, Z.; Li, R. K.; Dunning, M.; Zheng, Q.; Weathersby, S. P.; Reid, A. H.; Coffee, R.; Makasyuk, I.; Edstrom, S.; McCormick, D.; Jobe, K.; Hast, C.; Glenzer, S. H.; Wang, X. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Sokolowski-Tinten, K. [Faculty of Physics and Centre for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, D-47048 Duisburg (Germany)

    2016-11-15

    We have developed a single-shot mega-electronvolt ultrafast-electron-diffraction system to measure the structural dynamics of warm dense matter. The electron probe in this system is featured by a kinetic energy of 3.2 MeV and a total charge of 20 fC, with the FWHM pulse duration and spot size at sample of 350 fs and 120 μm respectively. We demonstrate its unique capability by visualizing the atomic structural changes of warm dense gold formed from a laser-excited 35-nm freestanding single-crystal gold foil. The temporal evolution of the Bragg peak intensity and of the liquid signal during solid-liquid phase transition are quantitatively determined. This experimental capability opens up an exciting opportunity to unravel the atomic dynamics of structural phase transitions in warm dense matter regime.

  3. Microscopic understanding of spin current probed by shot noise

    Science.gov (United States)

    Arakawa, Tomonori

    The spin currents is one of key issue in the spintronics field and the generation and detection of those have been intensively studied by using various materials. The analysis of experiments, however, relies on phenomenological parameters such as spin relaxation length and spin flip time. The microscopic nature of the spin current such as energy distribution and energy relaxation mechanism, has not yet well understood. To establish a better microscopic understanding of spin currents, I focused on the shot noise measurement which is well established technique in the field of mesoscopic physics [Y. M. Blanter and M. B üttiker, Phys. Rep. 336, 1 (2000).]. Although there are many theoretically works about shot noise in the presence of spin currents, for example detection of spin accumulation [J. Meair, P. Stano, and P. Jacquod, Phys. Rev. B 84 (2011).], estimation of spin flip currents, and so on, these predictions have never been experimentally confirmed. In this context, we reported the first experimental detention of shot noise in the presence of the spin accumulation in a (Ga,Mn)As/tunnel barrier/n-GaAs based lateral spin valve device [T. Arakawa et al., Phys. Rev. Lett. 114, 016601 (2015).]. Together with this result, we found however that the effective temperature of the spin current drastically increases due to the spin injection process. This heating of electron system could be a big problem to realize future spin current devices by using quantum coherence, because the effective temperature rise directly related to the destruction of the coherence of the spin current. Therefore, then we focused on the mechanism of this heating and the energy relaxation in a diffusive channel. By measuring current noise and the DC offset voltage in the usual non-local spin valve signal as a function of the spin diffusion channel length, we clarified that the electron-electron interaction length, which is the characteristic length for the relaxation of the electron system, is

  4. Gas detectors for x-ray lasers

    International Nuclear Information System (INIS)

    Tiedtke, K.; Feldhaus, J.; Hahn, U.; Jastrow, U.; Nunez, T.; Tschentscher, T.; Bobashev, S. V.; Sorokin, A. A.; Hastings, J. B.; Moeller, S.; Cibik, L.; Gottwald, A.; Hoehl, A.; Kroth, U.; Krumrey, M.; Schoeppe, H.; Ulm, G.; Richter, M.

    2008-01-01

    We have developed different types of photodetectors that are based on the photoionization of a gas at a low target density. The almost transparent devices were optimized and tested for online photon diagnostics at current and future x-ray free-electron laser facilities on a shot-to-shot basis with a temporal resolution of better than 100 ns. Characterization and calibration measurements were performed in the laboratory of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY II in Berlin. As a result, measurement uncertainties of better than 10% for the photon-pulse energy and below 20 μm for the photon-beam position were achieved at the Free-electron LASer in Hamburg (FLASH). An upgrade for the detection of hard x-rays was tested at the Sub-Picosecond Photon Source in Stanford

  5. Gas detectors for x-ray lasers

    Science.gov (United States)

    Tiedtke, K.; Feldhaus, J.; Hahn, U.; Jastrow, U.; Nunez, T.; Tschentscher, T.; Bobashev, S. V.; Sorokin, A. A.; Hastings, J. B.; Möller, S.; Cibik, L.; Gottwald, A.; Hoehl, A.; Kroth, U.; Krumrey, M.; Schöppe, H.; Ulm, G.; Richter, M.

    2008-05-01

    We have developed different types of photodetectors that are based on the photoionization of a gas at a low target density. The almost transparent devices were optimized and tested for online photon diagnostics at current and future x-ray free-electron laser facilities on a shot-to-shot basis with a temporal resolution of better than 100 ns. Characterization and calibration measurements were performed in the laboratory of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY II in Berlin. As a result, measurement uncertainties of better than 10% for the photon-pulse energy and below 20 μm for the photon-beam position were achieved at the Free-electron LASer in Hamburg (FLASH). An upgrade for the detection of hard x-rays was tested at the Sub-Picosecond Photon Source in Stanford.

  6. X-ray laser '' oscillator-amplifier'' experiments

    International Nuclear Information System (INIS)

    Shimkaveg, G.M.; Carter, M.R.; Young, B.K.F.; Walling, R.S.; Osterheld, A.L.; Trebes, J.E.; London, R.A.; Ratowsky, R.P.; Stewart, R.E.; Craxton, R.S.

    1993-01-01

    We present results from experiments directed toward increasing the degree of transverse coherence in x-ray laser beams. We have concentrated on the neon-like yttrium (Z=39) collisionally-pumped x-ray laser as the test system for these studies because of its unique combination of brightness, monochromaticity, and high-reflectivity optics availability. Attempts at improving laser performance using proximate feedback optics failed. Modest success has been found to date in ''double foil'' experiments, involving two x-ray lasers spatially separated by 29 cm and shot sequentially in an ''oscillator-amplifier'' configuration

  7. Laser amplitude stabilization for advanced interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Barr, B W; Strain, K A; Killow, C J

    2005-01-01

    We present results of experiments into the stabilization of the amplitude of Nd:YAG lasers for use in advanced gravitational wave detectors. By feeding back directly to the pump-diode driving current we achieved shot-noise-limited stabilization at frequencies up to several kHz with some residual noise at lower frequencies (sub ∼100 Hz). The method used is applicable to higher powered laser systems planned for advanced interferometric gravitational wave detectors

  8. Impact of environmental contamination on laser induced damage of silica optics in Laser MegaJoule

    International Nuclear Information System (INIS)

    Bien-Aime, K.

    2009-11-01

    Laser induced damage impact of molecular contamination on fused polished silica samples in a context of high power laser fusion facility, such as Laser MegaJoule (LMJ) has been studied. One of the possible causes of laser induced degradation of optical component is the adsorption of molecular or particular contamination on optical surfaces. In the peculiar case of LMJ, laser irradiation conditions are a fluence of 10 J/cm 2 , a wavelength of 351 nm, a pulse duration of 3 ns for a single shot/days frequency. Critical compounds have been identified thanks to environmental measurements, analysis of material outgassing, and identification of surface contamination in the critical environments. Experiments of controlled contamination involving these compounds have been conducted in order to understand and model mechanisms of laser damage. Various hypotheses are proposed to explain the damage mechanism. (author)

  9. Laser pulse shape design for laser-indirect-driven quasi-isentropic compression experiments

    Science.gov (United States)

    Xue, Quanxi; Jiang, Shaoen; Wang, Zhebin; Wang, Feng; Zhao, Xueqing; Ding, Yongkun

    2018-02-01

    Laser pulse shape design is a key work in the design of indirect-laser-driven experiments, especially for long pulse laser driven quasi-isentropic compression experiments. A method for designing such a laser pulse shape is given here. What's more, application experiments were performed, and the results of a typical shot are presented. At last of this article, the details of the application of the method are discussed, such as the equation parameter choice, radiation ablation pressure expression, and approximations in the method. The application shows that the method can provide reliable descriptions of the energy distribution in a hohlraum target; thus, it can be used in the design of long-pulse laser driven quasi-isentropic compression experiments and even other indirect-laser-driven experiments.

  10. Shot noise in systems with semi-Dirac points

    International Nuclear Information System (INIS)

    Zhai, Feng; Wang, Juan

    2014-01-01

    We calculate the ballistic conductance and shot noise of electrons through a two-dimensional stripe system (width W ≫ length L) with semi-Dirac band-touching points. We find that the ratio between zero-temperature noise power and mean current (the Fano factor) is highly anisotropic. When the transport is along the linear-dispersion direction and the Fermi energy is fixed at the semi-Dirac point, the Fano factor has a universal value F = 0.179 while a minimum conductivity exists and scales with L 1∕2 . Along the parabolic dispersion direction, the Fano factor at the semi-Dirac point has a contact-independent limit exceeding 0.9, which varies weakly with L due to the common-path interference of evanescent waves. Our findings suggest a way to discern the type of band-touching points

  11. Observation of radiation pressure shot noise on a macroscopic object.

    Science.gov (United States)

    Purdy, T P; Peterson, R W; Regal, C A

    2013-02-15

    The quantum mechanics of position measurement of a macroscopic object is typically inaccessible because of strong coupling to the environment and classical noise. In this work, we monitor a mechanical resonator subject to an increasingly strong continuous position measurement and observe a quantum mechanical back-action force that rises in accordance with the Heisenberg uncertainty limit. For our optically based position measurements, the back-action takes the form of a fluctuating radiation pressure from the Poisson-distributed photons in the coherent measurement field, termed radiation pressure shot noise. We demonstrate a back-action force that is comparable in magnitude to the thermal forces in our system. Additionally, we observe a temporal correlation between fluctuations in the radiation force and in the position of the resonator.

  12. Study of transient turbine shot without bypass in a BWR

    International Nuclear Information System (INIS)

    Vallejo Q, J. A.; Martin del Campo M, C.; Fuentes M, L.; Francois L, J. L.

    2015-09-01

    The study and analysis of operational transients are important for predicting the behavior of a system to short-terms events and the impact that would cause this transition. For the nuclear industry these studies are indispensable due to economic, environmental and social impacts that could result in an accident during the operation of a nuclear reactor. In this paper the preparation, simulation and analysis of results of a turbine shot transient, which is not taken into operation the bypass is presented. The study is realized for a BWR of 2027 MWt, to an intermediate cycle life and using the computer code Simulate-3K a depressurization stage of the vessel is created which shows the response of other security systems and gives a coherent prediction to the event presented type. (Author)

  13. Shot noise in a harmonically driven ballistic graphene transistor

    Science.gov (United States)

    Korniyenko, Y.; Shevtsov, O.; Löfwander, T.

    2017-04-01

    We study time-dependent electron transport and quantum noise in a ballistic graphene field effect transistor driven by an ac gate potential. The nonlinear response to the ac signal is computed through Floquet theory for scattering states and Landauer-Büttiker theory for charge current and its fluctuations. Photon-assisted excitation of a quasibound state in the top-gate barrier leads to resonances in transmission that strongly influence the noise properties. For strong doping of graphene under source and drain contacts, when electrons are transmitted through the channel via evanescent waves, the resonance leads to a substantial suppression of noise. The Fano factor is then reduced well below the pseudodiffusive value, F tunneling (total suppression of back-reflection) persists for perpendicular incidence also when the barrier is driven harmonically. Although the transmission is inelastic and distributed among sideband energies, a sum rule leads to total suppression of shot noise.

  14. Single-shot polarimetry imaging of multicore fiber.

    Science.gov (United States)

    Sivankutty, Siddharth; Andresen, Esben Ravn; Bouwmans, Géraud; Brown, Thomas G; Alonso, Miguel A; Rigneault, Hervé

    2016-05-01

    We report an experimental test of single-shot polarimetry applied to the problem of real-time monitoring of the output polarization states in each core within a multicore fiber bundle. The technique uses a stress-engineered optical element, together with an analyzer, and provides a point spread function whose shape unambiguously reveals the polarization state of a point source. We implement this technique to monitor, simultaneously and in real time, the output polarization states of up to 180 single-mode fiber cores in both conventional and polarization-maintaining fiber bundles. We demonstrate also that the technique can be used to fully characterize the polarization properties of each individual fiber core, including eigen-polarization states, phase delay, and diattenuation.

  15. Josephson radiation and shot noise of a semiconductor nanowire junction

    Science.gov (United States)

    van Woerkom, David J.; Proutski, Alex; van Gulik, Ruben J. J.; Kriváchy, Tamás; Car, Diana; Plissard, Sébastian R.; Bakkers, Erik P. A. M.; Kouwenhoven, Leo P.; Geresdi, Attila

    2017-09-01

    We measured the Josephson radiation emitted by an InSb semiconductor nanowire junction utilizing photon-assisted quasiparticle tunneling in an ac-coupled superconducting tunnel junction. We quantify the action of the local microwave environment by evaluating the frequency dependence of the inelastic Cooper-pair tunneling of the nanowire junction and find the zero-frequency impedance Z (0 )=492 Ω with a cutoff frequency of f0=33.1 GHz . We extract a circuit coupling efficiency of η ≈0.1 and a detector quantum efficiency approaching unity in the high-frequency limit. In addition to the Josephson radiation, we identify a shot noise contribution with a Fano factor F ≈1 , consistently with the presence of single electron states in the nanowire channel.

  16. FT-IR microspectroscopic study of shot formation in melt-blown webs.

    Science.gov (United States)

    Ko, W C; Bresee, R R

    2003-06-01

    We used Fourier transform infrared (FT-IR) microspectroscopy to investigate the chemical nature of fibers and defects called "shot" in melt-blown webs. Spectral differences were observed and evaluated in light of known thermal and oxidative degradation reactions for conditions comparable to those we used for melt blowing. Three different isotactic polypropylene polymers were evaluated in terms of the amount of shot produced and the amount of oxidative degradation exhibited by fibers and shot particles from each polymer. Little oxidative degradation was observed in fibers and the amount of degradation in fibers varied little for the three polymers we evaluated. Substantially more degradation was observed in shot particles, and the amount of degradation varied among the three polymers. Compared to polymer bound for fibers, we concluded that high temperature and mechanical shear in the extruder may introduce more chain scission in polymer bound for shot particles. Autoxidation reactions may occur after melt exits the die, and our data indicated that more oxidative degradation occurred in polymer that became shot particles than polymer that became fibers. The most favorable site for oxidation seemed to be tertiary rather than methylene hydrogen. Overall, the thermal history of polymer that becomes shot particles may be significantly different than the thermal history of polymer that becomes fibers, and this difference may have influenced shot formation.

  17. Fatigue and heat transfer behaviour of shot penned aluminium alloy for automobile applications

    Energy Technology Data Exchange (ETDEWEB)

    Nadkarni, V.S.; Sharma, M.C. [M.A.C.T., Bhopal (India). Dept. of Mech. Eng.

    2000-07-01

    In the present investigation glass beads and zirconium oxide shots were used as media to shot peening aluminium alloy specimens. Fatigue and boiling heat transfer behaviour of this alloy after shot peening was studied. Out of 0.2N and 0.4N peening intensities, 0.4N gave higher improvement on fatigue strength and boiling heat transfer. Fatigue of butt welded aluminium joints were also studied. Shot peening with zirconium oxide shots at 0.4N intensity was found to be more advantageous than glass beads. Welding reduces 19.4% fatigue strength compared to virgin samples, but shot peening could improve fatigue strength by 12% compared to welded samples. Effect of corrosive (3N Nacl) environment on fatigue strength was also studied. Zir shots were found to be economical. The commercial application of shot peening in automobiles to enhance boiling heat transfer was also studied. The heat transfer media then used was the coolant commonly used in car radiators. That was 95% ethylene glycol with some inhibitor to prevent corrosion. This was a mixture of water and glycol in 3:1 ratio. The optimum surface roughness was 6.2 {mu}m which gave optimum heat transfer at 90% improvement in boiling heat transfer compared to unpeened samples. (orig.)

  18. Different intensities of basketball drills affect jump shot accuracy of expert and junior players.

    Science.gov (United States)

    Marcolin, Giuseppe; Camazzola, Nicola; Panizzolo, Fausto Antonio; Grigoletto, Davide; Paoli, Antonio

    2018-01-01

    In basketball a maximum accuracy at every game intensity is required while shooting. The aim of the present study was to investigate the acute effect of three different drill intensity simulation protocols on jump shot accuracy in expert and junior basketball players. Eleven expert players (age 26 ± 6 yrs, weight 86 ± 11 kg, height 192 ± 8 cm) and ten junior players (age 18 ± 1 yrs, weight 75 ± 12 kg, height 184 ± 9 cm) completed three series of twenty jump shots at three different levels of exertion. Counter Movement Jump (CMJ) height was also measured after each series of jump shots. Exertion's intensity was induced manipulating the basketball drills. Heart rate was measured for the whole duration of the tests while the rating of perceived exertion (RPE) was collected at the end of each series of shots. Heart rate and rating of perceived exertion (RPE) were statistically different in the three conditions for both expert and junior players. CMJ height remained almost unchanged in both groups. Jump shot accuracy decreased with increasing drills intensity both in experts and junior players. Expert players showed higher accuracy than junior players for all the three levels of exertion (83% vs 64%, p  shots compared to the first ten shots (82% vs 70%, p  jump shot accuracy during matches.

  19. Investigations of shot reproducibility for the SMP diode at 4.5 MV.

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Nichelle [National Security Technologies, LLC, Las Vegas, NV (United States); Crain, Marlon D. [National Security Technologies, LLC, Las Vegas, NV (United States); Droemer, Darryl W. [National Security Technologies, LLC, Las Vegas, NV (United States); Gignac, Raymond Edward [National Security Technologies, LLC, Las Vegas, NV (United States); Lare, Gregory A. [National Security Technologies, LLC, Las Vegas, NV (United States); Molina, Isidro [National Security Technologies, LLC, Las Vegas, NV (United States); Obregon, Rafael [National Security Technologies, LLC, Las Vegas, NV (United States); Smith, Chase C. [National Security Technologies, LLC, Las Vegas, NV (United States); Wilkins, Frank Lee [National Security Technologies, LLC, Las Vegas, NV (United States); Welch, Dale Robert [Voss Scientific, LLC, Albuquerque, NM (United States); Cordova, Steve Ray; Gallegos, M.; Johnston, Mark D.; Kiefer, Mark Linden; Leckbee, Joshua J.; Nielsen, Daniel Scott; Oliver, Bryan Velten; Renk, Timothy Jerome; Romero, Tobias; Webb, Timothy Jay; Ziska, Derek Raymond

    2013-11-01

    In experiments conducted on the RITS-6 accelerator, the SMP diode exhibits sig- ni cant shot-to-shot variability. Speci cally, for identical hardware operated at the same voltage, some shots exhibit a catastrophic drop in diode impedance. A study is underway to identify sources of shot-to-shot variations which correlate with diode impedance collapse. To remove knob emission as a source, only data from a shot series conducted with a 4.5-MV peak voltage are considered. The scope of this report is limited to sources of variability which occur away from the diode, such as power ow emission and trajectory changes, variations in pulsed power, dustbin and transmission line alignment, and di erent knob shapes. We nd no changes in the transmission line hardware, alignment, or hardware preparation methods which correlate with impedance collapse. However, in classifying good versus poor shots, we nd that there is not a continuous spectrum of diode impedance behavior but that the good and poor shots can be grouped into two distinct impedance pro les. This result forms the basis of a follow-on study focusing on the variability resulting from diode physics. 3

  20. Image2Emoji: Zero-shot Emoji Prediction for Visual Media

    NARCIS (Netherlands)

    Cappallo, S.; Mensink, T.; Snoek, C.G.M.

    2015-01-01

    We present Image2Emoji, a multi-modal approach for generating emoji labels for an image in a zero-shot manner. Different from existing zero-shot image-to-text approaches, we exploit both image and textual media to learn a semantic embedding for the new task of emoji prediction. We propose that the

  1. Who Takes Advantage of Free Flu Shots? Examining the Effects of an Expansion in Coverage

    NARCIS (Netherlands)

    Carman, K.G.; Mosca, I.

    2011-01-01

    Because of the high risk of costly complications (including death) and the externalities of contagious diseases, many countries provide free flu shots to certain populations free of charge. This paper examines the expansion of the free flu shot program in the Netherlands. This program expanded in

  2. Shot reproducibility of the self-magnetic-pinch diode at 4.5 MV

    Directory of Open Access Journals (Sweden)

    Nichelle Bennett

    2014-05-01

    Full Text Available In experiments conducted at Sandia National Laboratories’ RITS-6 accelerator, the self-magnetic-pinch diode exhibits significant shot-to-shot variability. Specifically, for identical hardware operated at the same voltage, some shots exhibit a catastrophic drop in diode impedance. A study is underway to identify sources of shot-to-shot variations which correlate with diode impedance collapse. The scope of this report is limited to data collected at 4.5-MV peak voltage and sources of variability which occur away from the diode, such as sheath electron emission and trajectories, variations in pulsed power, load and transmission line alignment, and different field shapers. We find no changes in the transmission line hardware, alignment, or hardware preparation methods which correlate with impedance collapse. However, in classifying good versus poor shots, we find that there is not a continuous spectrum of diode impedance behavior but that the good and poor shots can be grouped into two distinct impedance profiles. In poor shots, the sheath current in the load region falls from 16%–30% of the total current to less than 10%. This result will form the basis of a follow-up study focusing on the variability resulting from diode physics.

  3. Effect of shot peening process on fatigue behavior of an alloyed austempered ductile iron

    Directory of Open Access Journals (Sweden)

    Amir Sadighzadeh Benam

    2011-08-01

    Full Text Available Shot peening is one of the most common surface treatments to improve the fatigue behavior of metallic parts. In this study the effect of shot peening process on the fatigue behavior of an alloyed austempered ductile iron (ADI has been studied. Austempering heat treatment consisted of austenitizing at 875℃ for 90 min followed by austempering at three different temperatures of 320, 365 and 400℃. Rotating-bending fatigue test was carried out on samples after shot peening by 0.4 – 0.6 mm shots. XRD and SEM analysis, micro hardness and roughness tests were carried out to study the fatigue behavior of the samples. Results indicate that the fatigue strengths of samples austempered at 320, 365 and 400℃ are increased by 27.3%, 33.3% and 48.4%, respectively, after shot peening process.

  4. Design and Implementation of Video Shot Detection on Field Programmable Gate Arrays

    Directory of Open Access Journals (Sweden)

    Jharna Majumdar

    2012-09-01

    Full Text Available Video has become an interactive medium of communication in everyday life. The sheer volume of video makes it extremely difficult to browse through and find the required data. Hence extraction of key frames from the video which represents the abstract of the entire video becomes necessary. The aim of the video shot detection is to find the position of the shot boundaries, so that key frames can be selected from each shot for subsequent processing such as video summarization, indexing etc. For most of the surveillance applications like video summery, face recognition etc., the hardware (real time implementation of these algorithms becomes necessary. Here in this paper we present the architecture for simultaneous accessing of consecutive frames, which are then used for the implementation of various Video Shot Detection algorithms. We also present the real time implementation of three video shot detection algorithms using the above mentioned architecture on FPGA (Field Programmable Gate Arrays.

  5. Acceptance test procedure, 241-SY-101/241-C-106 shot loading system

    International Nuclear Information System (INIS)

    Ostrom, M.J.

    1994-01-01

    This Acceptance Test Procedure is for the 241-SY-101/241-C-106 Shot Loading System. The procedure will test the components of the Shot Loading System and its capability of adequately loading shot into the annular space of the Container. The loaded shot will provide shielding as required for transporting and storage of a contaminated pump after removal from the tank. This test serves as verification that the SLS is acceptable for use in the pump removal operations for Tanks 241-SY-101, 241-C-106 and 241-AY-102. The pump removal operation for these three tanks will be performed by two different organizations with different equipment, but the Shot Loading System will be compatible between the two operations

  6. Real-time single-shot electron bunch length measurements

    CERN Document Server

    Wilke, I; Gillespie, W A; Berden, G; Knippels, G M H; Meer, A F G

    2002-01-01

    Linear accelerators employed as drivers for X-ray free electron lasers (FELs) require relativistic electron bunch with sub-picosecond bunch length. Precise bunch length measurements are important for the tuning and operation of the FELs. Previously, we have demonstrated that electro-optic detection is a powerful technique for sub-picosecond electron bunch length measurements. In those experiments, the measured bunch length was the average of all electron bunches within a macropulse. Here, for the first time, we present the measurement of the length of individual electron bunches using a development of our previous technique. In this experiment, the longitudinal electron bunch shape is encoded electro-optically on to the frequency spectrum of a chirped laser pulse. Subsequently, the laser pulse is dispersed by a grating and the spectrum is imaged with a CCD camera. Single bunch measurements are achieved by using a nanosecond gated camera, and synchronizing the gate with both the electron bunch and the laser pu...

  7. On the residual stress modeling of shot-peened AISI 4340 steel: finite element and response surface methods

    Science.gov (United States)

    Asgari, Ali; Dehestani, Pouya; Poruraminaie, Iman

    2018-02-01

    Shot peening is a well-known process in applying the residual stress on the surface of industrial parts. The induced residual stress improves fatigue life. In this study, the effects of shot peening parameters such as shot diameter, shot speed, friction coefficient, and the number of impacts on the applied residual stress will be evaluated. To assess these parameters effect, firstly the shot peening process has been simulated by finite element method. Then, effects of the process parameters on the residual stress have been evaluated by response surface method as a statistical approach. Finally, a strong model is presented to predict the maximum residual stress induced by shot peening process in AISI 4340 steel. Also, the optimum parameters for the maximum residual stress are achieved. The results indicate that effect of shot diameter on the induced residual stress is increased by increasing the shot speed. Also, enhancing the friction coefficient magnitude always cannot lead to increase in the residual stress.

  8. Laser Technology.

    Science.gov (United States)

    Gauger, Robert

    1993-01-01

    Describes lasers and indicates that learning about laser technology and creating laser technology activities are among the teacher enhancement processes needed to strengthen technology education. (JOW)

  9. Ultrasensitive laser measurements without tears.

    Science.gov (United States)

    Hobbs, P C

    1997-02-01

    Several easily implemented devices for doing ultrasensitive optical measurements with noisy lasers are presented. They are all-electronic noise cancellation circuits that largely eliminate excess laser intensity noise as a source of measurement error and are widely applicable. Shot-noise-limited optical measurements can now easily be made at baseband with noisy lasers. These circuits are especially useful in situations where strong intermodulation effects exist, such as current-tuned diode laser spectroscopy. These inexpensive devices (parts cost approximately $10) can be optimized for particular applications such as wideband or differential measurements. Although they cannot eliminate phase noise effects, they can reduce amplitude noise by 55-70 dB or more, even in unattended operation, and usually achieve the shot-noise limit. With 1-Hz signal-to-noise ratios of 150-160 dB, they allow performance equal or superior to a complex heterodyne system in many cases, while using much simpler dual-beam or homodyne approaches. Although these devices are related to earlier differential and ratiometric techniques, their noise cancellation performance is much better. They work well at modulation frequencies from dc to several megahertz and should be extensible to approximately 100 MHz. The circuits work by subtracting photocurrents directly, with feedback applied outside the signal path to continuously adjust the subtraction for perfect balance; thus the excess noise and spurious modulation ideally cancel at all frequencies, leaving only the shot noise. The noise cancellation bandwidth is independent of the feedback bandwidth; it depends only on the speeds of the photodiodes and of the bipolar junction transistors used. Two noise-canceled outputs are available; one is a high-pass filtered voltage proportional to the signal photocurrent and the other is a low-pass filtered voltage related to the log ratio of the signal and comparison photocurrents. For reasonable current

  10. Ablation mass features in multi-pulses femtosecond laser ablate molybdenum target

    Science.gov (United States)

    Zhao, Dongye; Gierse, Niels; Wegner, Julian; Pretzler, Georg; Oelmann, Jannis; Brezinsek, Sebastijan; Liang, Yunfeng; Neubauer, Olaf; Rasinski, Marcin; Linsmeier, Christian; Ding, Hongbin

    2018-03-01

    In this study, the ablation mass features related to reflectivity of bulk Molybdenum (Mo) were investigated by a Ti: Sa 6 fs laser pulse at central wavelength 790 nm. The ablated mass removal was determined using Confocal Microscopy (CM) technique. The surface reflectivity was calibrated and measured by a Lambda 950 spectrophotometer as well as a CCD camera during laser ablation. The ablation mass loss per pulse increase with the increasing of laser shots, meanwhile the surface reflectivity decrease. The multi-pulses (100 shots) ablation threshold of Mo was determined to be 0.15 J/cm2. The incubation coefficient was estimated as 0.835. The reflectivity change of the Mo target surface following multi-pulses laser ablation were studied as a function of laser ablation shots at various laser fluences from 1.07 J/cm2 to 36.23 J/cm2. The results of measured reflectivity indicate that surface reflectivity of Mo target has a significant decline in the first 3-laser pulses at the various fluences. These results are important for developing a quantitative analysis model for laser induced ablation and laser induced breakdown spectroscopy for the first wall diagnosis of EAST tokamak.

  11. Fano–Kondo shot noise in a quantum dot embedded interferometer irradiated with microwave fields

    International Nuclear Information System (INIS)

    Zhao, Hong-Kang; Zou, Wei-Ke

    2015-01-01

    The shot noise of a quantum dot embedded Aharonov–Bohm (AB) interferometer under the perturbation of microwave fields is investigated by employing equation of motion method. The frequency-dependent shot noise formula is derived, and the photon-assisted Fano–Kondo resonance, the suppression of Kondo peak are presented with increasing the direct tunneling strength. The interference and correlation of electrons induce the asymmetric resonant peak–valley behavior of shot noise. The enhancement and suppression of shot noise are resulting from the competition of incoherent correlation and destructive interference effects, and super-Poissonian and sub-Poissonian noise can be adjusted by the applied photon irradiation, gate bias, and direct tunneling strength. The periodic oscillation versus AB phase with period 2π appears to show plateaus and flat valleys. - Highlights: • The quantum dot embedded Aharonov–Bohm interferometer under the perturbation of ac fields have been investigated. • The frequency-dependent shot noise formula has been derived. • The photon-assisted Fano–Kondo resonant shot noise and Fano factor have been evaluated. • The enhancement and suppression of shot noise can be adjusted by the applied photon irradiation. • The periodic oscillation versus Aharonov–Bohm phase shows plateaus and flat valleys

  12. Effect of shot peening on surface fatigue life of carburized and hardened AISI 9310 spur gears

    Science.gov (United States)

    Townsend, D. P.; Zaretsky, E. V.

    1982-01-01

    Surface fatigue tests were conducted on two groups of AISI 9310 spur gears. Both groups were manufactured with standard ground tooth surfaces, with the second group subjected to an additional shot peening process on the gear tooth flanks. The gear pitch diameter was 8.89 cm (3.5 in.). Test conditions were a gear temperature of 350 K (170 F), a maximum Hertz stress of 1.71 billion N/sq m (248,000 psi), and a speed of 10,000 rpm. The shot peened gears exhibited pitting fatigue lives 1.6 times the life of standard gears without shot peening. Residual stress measurements and analysis indicate that the longer fatigue life is the result of the higher compressive stress produced by the shot peening. The life for the shot peened gear was calculated to be 1.5 times that for the plain gear by using the measured residual stress difference for the standard and shot peened gears. The measured residual stress for the shot peened gears was much higher than that for the standard gears.

  13. Subjective State, Blood Pressure, and Behavioral Control Changes Produced by an "Energy Shot"

    Science.gov (United States)

    Marczinski, Cecile A; Stamates, Amy L; Ossege, Julianne; Maloney, Sarah F; Bardgett, Mark E; Brown, Clifford J

    2014-06-01

    Background: Energy drinks and energy shots are popular consumer beverages that are advertised to increase feelings of alertness. Typically, these products include high levels of caffeine, a mild psychostimulant drug. The scientific evidence demonstrating the specific benefits of energy products to users in terms of subjective state and objective performance is surprisingly lacking. Moreover, there are rising health concerns associated with the use of these products. Therefore, the purpose of this study was to investigate the acute effects of a popular energy shot (5-Hour Energy ® ) on subjective and objective measures that were assessed hourly for 6 hours following consumption. Methods: Participants ( n =14) completed a three-session study where they received the energy shot, a placebo control, and no drink. Following dose administration, participants completed subjective Profile of Mood States ratings hourly for 6 hours. Participants also repeatedly completed a behavioral control task (the cued go/no-go task) and provided blood pressure and pulse rate readings at each hour. Results: Consumption of the energy shot did improve subjective state, as measured by increased ratings of vigor and decreased ratings of fatigue. However, the energy shot did not alter objective performance, which worsened over time. Importantly, the energy shot elevated both systolic and diastolic blood pressure. Conclusions: Consumption of one energy shot may only result in modest benefits to subjective state. Individuals with preexisting hypertension or other medical conditions should be cautious about using these new consumer products.

  14. Using persuasive messages to encourage hunters to support regulation of lead shot

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.; Penning, William; Doncarlos, Kathy

    2012-01-01

    Lead shot from hunting adds the toxic metal to environments worldwide. The United States banned lead shot for hunting waterfowl in 1991 and 26 states have lead shot restrictions beyond those mandated for waterfowl hunting. The Minnesota Department of Natural Resources (MDNR) was interested in studying hunter attitudes about expanded restrictions on the use of lead shot for hunting small game to understand what communication strategies might increase public support for potential restrictions on lead shot. We mailed messages about lead shot, including 1,200 control messages and 400 of each of 9 treatment messages, and surveys to 4,800 resident small game hunters. We compared attitudes and intentions related to a possible ban among control and treatment groups. Compared to the control message, all treatment messages elicited more positive attitudes and intentions to support a ban. A basic factual message, messages with references to Ducks Unlimited, and a first-person narrative message generated the strongest support for a ban. Results also demonstrated a substantial relationship between the use of lead shot and response to persuasive messages supporting a ban.

  15. Radiologically contaminated lead shot reuse at the Idaho National Engineering Laboratory (INEL)

    International Nuclear Information System (INIS)

    Heileson, W.M.; Grant, R.P.

    1995-01-01

    This project involved the utilization of radioactively contaminated lead shot located at the Radioactive Waste Management Complex (RWMC) for radiation shielding on a radioactive liquid process tank located at Argonne National Laboratory-West (ANL-W). The use of previously contaminated shot precludes the radioactive contamination of clean shot. With limited treatment and disposal options for contaminated lead shot, the reuse of lead for shielding is significant due to the inherent characteristic of becoming a mixed waste when radiologically contaminated. The INEL conducted a lead cleanup campaign in 1990. This was designed to ensure control of potential Resource Conservation and Recovery Act (RCRA) regulated waste. Contaminated lead from throughout the INEL, was containerized per the lead Waste Acceptance Criteria at the generator sites. Limited areas at the INEL are designated for mixed waste storage. As a result, some of the lead was stored at the RWMC in the air support weather shield (ASWS). This lead was contaminated with small amounts of fission product contamination. The lead was in the form of shot, brick, sheet, casks, and other various sized pieces. In 1993, ANL-W identified a need for lead shot to be used as shielding in a radioactive liquid waste storage and processing tank at the Fuel Cycle Facility (FCF). The contaminated lead used on this project had been in storage as mixed waste at the RWMC. This paper will focus on the processes and problems encountered to utilize the contaminated lead shot

  16. Feasibility study of a single-shot 3D electron bunch shape monitor with an electro-optic sampling technique

    Directory of Open Access Journals (Sweden)

    Yuichi Okayasu

    2013-05-01

    Full Text Available We developed a three-dimensional electron bunch charge distribution (3D-BCD monitor with single-shot detection, and a spectral decoding based electro-optic (EO sampling technique for a nondestructive monitor enables real-time reconstruction of the three-dimensional distribution of a bunch charge. We realized three goals by simultaneously probing a number of Pockels EO crystals that surround the electron beam axis with hollow and radial polarized laser pulses. First, we performed a feasibility test as a simple case of a 3D-BCD monitor probing two ZnTe crystals as EO detectors installed on the opposite angle to the electron beam axis and confirmed that we simultaneously obtained both EO signals. Since the adopted hollow probe laser pulse is not only radially polarized but also temporally shifted azimuthally, some disorders in the radial polarization distribution of such a laser pulse were numerically analyzed with a plane-wave expansion method. Based on the above investigations, the 3D-BCD monitor is feasible both in experimental and numerical estimations. Furthermore, we previously developed a femtosecond response organic crystal as a Pockels EO detector and a broadband probe laser (≥350  nm in FWHM; the 3D-BCD monitor realizes 30- to 40-fs (FWHM temporal resolution. Eventually, the monitor is expected to be equipped in such advanced accelerators as XFEL to measure and adjust the electron bunch charge distribution in real time. The 3D-BCD measurement works as a critical tool to provide feedback to seeded FELs.

  17. Ultrafast Diagnostics for Electron Beams from Laser Plasma Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Matlis, N. H.; Bakeman, M.; Geddes, C. G. R.; Gonsalves, T.; Lin, C.; Nakamura, K.; Osterhoff, J.; Plateau, G. R.; Schroeder, C. B.; Shiraishi, S.; Sokollik, T.; van Tilborg, J.; Toth, Cs.; Leemans, W. P.

    2010-06-01

    We present an overview of diagnostic techniques for measuring key parameters of electron bunches from Laser Plasma Accelerators (LPAs). The diagnostics presented here were chosen because they highlight the unique advantages (e.g., diverse forms of electromagnetic emission) and difficulties (e.g., shot-to-shot variability) associated with LPAs. Non destructiveness and high resolution (in space and time and energy) are key attributes that enable the formation of a comprehensive suite of simultaneous diagnostics which are necessary for the full characterization of the ultrashort, but highly-variable electron bunches from LPAs.

  18. Investigation of Laser Peening Effects on Hydrogen Charged Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Zaleski, Tania M. [San Jose State Univ., CA (United States)

    2008-10-30

    Hydrogen-rich environments such as fuel cell reactors can exhibit damage caused by hydrogen permeation in the form of corrosion cracking by lowering tensile strength and decreasing material ductility. Coatings and liners have been investigated, but there were few shot-peening or laser peening studies referenced in the literature with respect to preventing hydrogen embrittlement. The surface compressive residual stress induced by laser peening had shown success in preventing stress corrosion cracking (SCC) for stainless steels in power plants. The question arose if the residual stresses induced by laser peening could delay the effects of hydrogen in a material. This study investigated the effect of laser peening on hydrogen penetration into metal alloys. Three areas were studied: laser peening, hydrogenation, and hydrogen detection. This study demonstrated that laser peening does not reduce the hydrogen permeation into a stainless steel surface nor does it prevent hydrogen embrittlement. The effect of laser peening to reduce hydrogen-assisted fatigue was unclear.

  19. Holographic Snapshots of Laser Wakefields

    Science.gov (United States)

    Downer, Michael

    2006-10-01

    Tabletop plasma accelerators driven by intense ultrashort laser pulses or charged-particle bunches can now produce GeV-range electron beams and femtosecond x-ray and gamma-ray pulses, providing compact radiation sources for application in medicine, nuclear engineering, materials science and high-energy physics. In these accelerators, electrons surf on >100 GeV/m electric fields (thousands of times stronger than in conventional accelerators) generated within plasma structures (e.g. electron plasma waves, ``bubbles'' devoid of electrons) propagating behind the driving pulse. Because of their microscopic size and luminal velocity, however, critical features of these structures that determine the energy, energy spread, collimation and charge of the accelerated beam have eluded direct single-shot observation, inhibiting progress in producing high quality beams and in correlating beam properties with wake structure. Here we demonstrate single shot visualization of laser wakefield accelerator (LWFA) structures for the first time, using Frequency Domain Holography (FDH), a technique designed to image structures propagating near light speed. Our holographic ``snapshots'' capture the evolution of multiple wake periods, and resolve wavefront curvature seen previously only in simulations. These previously invisible features underlie wave breaking, electron injection and focusing within the wake, the key determinants of beam quality. We reconstruct wake morphology in real-time, providing experimental feedback and optimization. Beyond accelerators, we anticipate that FDH will provide an unprecedented visualization and feedback capability for structures created in diverse laser- and particle-plasma interactions, including fast ignition for laser fusion and plasma-based amplification and compresssion of ultra-intense laser pulses.

  20. Single shot ultrafast dynamic ellipsometry (UDE) of laser-driven shocks in single crystal explosives

    Energy Technology Data Exchange (ETDEWEB)

    Whitley, Von H [Los Alamos National Laboratory; Mcgrane, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Eakins, Dan E [Los Alamos National Laboratory; Bolme, Cindy A [Los Alamos National Laboratory

    2009-01-01

    We report on the first experiments to measure states in shocked energetic single crystals with dynamic ellipsometry. We demonstrate that these ellipsometric techniques can produce reasonable Hugoniot values using small amounts of crystalline RDX and PETN. Pressures, particle velocities and shock velocities obtained using shocked ellipsometry are comparable to those found using gas-gun flyer plates and molecular dynamics calculations. The adaptation of the technique from uniform thin films of polymers to thick non-perfect crystalline materials was a significant achievement. Correct sample preparation proved to be a crucial component. Through trial and error, we were able to resolve polishing issues, sample quality problems, birefringence effects and mounting difficulties that were not encountered using thin polymer films.

  1. Self-organized compound pattern and pulsation of dissipative solitons in a passively mode-locked fiber laser

    Science.gov (United States)

    Wang, Zhenhong; Wang, Zhi; Liu, Yange; He, Ruijing; Zhao, Jian; Wang, Guangdou; Yang, Guang

    2018-02-01

    We experimentally observe soliton self-organization and pulsation in a passively mode-locked fiber laser. The optomechanical interaction in the optical fiber is key to the formation of equidistant soliton bunches. These solitons simultaneously undergo a pulsation process with a period corresponding to tens of the cavity round trip time. Using the dispersive Fourier transformation technique, we find that the Kelly sidebands in the shot-to-shot spectra appear periodically, synchronizing with the pulsation.

  2. Robust shot-noise measurement for continuous-variable quantum key distribution

    Science.gov (United States)

    Kunz-Jacques, Sébastien; Jouguet, Paul

    2015-02-01

    We study a practical method to measure the shot noise in real time in continuous-variable quantum key distribution systems. The amount of secret key that can be extracted from the raw statistics depends strongly on this quantity since it affects in particular the computation of the excess noise (i.e., noise in excess of the shot noise) added by an eavesdropper on the quantum channel. Some powerful quantum hacking attacks relying on faking the estimated value of the shot noise to hide an intercept and resend strategy were proposed. Here, we provide experimental evidence that our method can defeat the saturation attack and the wavelength attack.

  3. SQUID based resistance bridge for shot noise measurement on low impedance samples

    OpenAIRE

    Jehl, X.; Payet-Burin, P.; Baraduc, C.; Calemczuk, R.; Sanquer, M.

    1999-01-01

    We present a resistance bridge which uses a SQUID to measure the shot noise in low impedance samples. The experimental requirements are high DC bias currents (typically 10mA) together with high AC sensitivity (pA/VHz). This system is used to investigate the shot noise in Superconductor/Normal/Superconductor junctions where Andreev reflection enhanced shot noise is expected. Because our setup has an intrinsic noise much smaller than the thermal noise of the resistance bridge at 4.2K, reliable ...

  4. Shot noise as a probe of spin-correlated transport through single atoms

    Science.gov (United States)

    Pradhan, S.; Fransson, J.

    2018-03-01

    We address the shot noise in the tunneling current through a local spin, pertaining to recent experiments on magnetic adatoms and single molecular magnets. We show that both uncorrelated and spin-correlated scattering processes contribute vitally to the noise spectrum. The spin-correlated scattering processes provide an additional contribution to the Landauer-Büttiker shot noise expression, accounting for correlations between the tunneling electrons and the localized spin moment. By calculating the Fano factor, we show that both super- and sub-Poissonian shot noise can be described within our approach. Our theory provides transparent insights into noise spectroscopy, consistent with recent experiments using local probing techniques on magnetic atoms.

  5. Vaccine shot-limiting: Estimating the prevalence, indicators, and impact on vaccination status - Michigan, 2012.

    Science.gov (United States)

    Weinberg, Meghan; Dietz, Stephanie; Potter, Rachel; Swanson, Robert; Miller, Corinne; McFadden, Jevon

    2017-02-15

    Concerns regarding vaccine safety and pain have prompted certain parents to limit the number of shots their child receives per visit. We estimated the prevalence of shot-limited children in Michigan, described their characteristics, assessed whether shot-limited children were up-to-date on recommended vaccinations, and investigated possible intervention points for vaccination education. We analyzed vaccination registry and birth record data of children born in Michigan during 2012 who had ⩾2 vaccination visits, with ⩾1 visits after age 5months. Shot-limited was defined as receiving ⩽2 shots at all visits through age 24months. Nonlimited children received >2 shots at ⩾1 visits. Up-to-date vaccination was based on receipt of a seven-vaccine series and was determined at ages 24months and 35months. Risk ratios (RR) were calculated using risk regression. Of 101,443 children, a total of 2,967 (3%) children were shot-limited. Mothers of shot-limited children were more likely to be white (RR: 1.2; 95% confidence interval [CI]: 1.2-1.2), college graduate (RR: 1.9; 95% CI: 1.9-2.0), and married (RR: 1.5; 95% CI: 1.5-1.5). Compared with nonlimited children, shot-limited children were more likely to be born in a nonhospital setting (RR: 11.7; 95% CI: 9.4-14.6) and have a midwife attendant (RR: 1.9; 95% CI: 1.7-2.1). Shot-limited children were less likely to be up-to-date on recommended vaccinations (RR: 0.2; 95% CI: 0.2-0.3); this association was stronger for those with a midwife birth attendant (RR: 0.1; 95% CI: 0.1-0.2) rather than a medical doctor (RR: 0.3; 95% CI: 0.2-0.3). Shot-limited children are less likely to be up-to-date on vaccinations, possibly leading to increased risk for vaccine-preventable diseases. This association was stronger for those with a midwife birth attendant. This analysis should prompt targeted education, such as to midwives, concerning risks associated with shot-limiting behavior. Published by Elsevier Ltd.

  6. Effects of shot peening on the residual stress of welded SS400 steel

    International Nuclear Information System (INIS)

    Lee, Jong Man; Kim, Tae Hyung; Cheong, Seong Kyun; Lee, Seung Ho

    2002-01-01

    The fatigue life of structures is usually determined by welding zone. The tensile residual stress, which is induced by welding, reduces the fatigue life and fatigue strength of welded structures. If we remove the tensile residual stress or induce the compressive residual stress, the fatigue life of welded structures will be improved. The change of hardness and compressive residual stress of welded zone after shot peening was investigated in this paper. The results show that the hardness was increased by shot peening. The residual stress was reduced by shot peening

  7. Study of the Powerful Nd:YLF Laser Amplifiers for the CTF3 Photoinjectors

    CERN Document Server

    Petrarca, M; Luchinin, G; Divall, M

    2011-01-01

    A high-power neodymium-doped yttrium lithium fluoride (Nd:YLF) mode-locked 1.5-GHz laser currently used to drive the two photoinjectors of the Compact Linear Collider Test Facility project at the European Organization for Nuclear Research is described. A phenomenological characterization of the two powerful Nd:YLF amplifiers is presented and compared with the measurements. The laser system operates in a saturated steady-state mode. This mode provides good shot-to-shot stability with pulse train mean power in the 10 kW range.

  8. "Heart Shots": a classroom activity to instigate active learning.

    Science.gov (United States)

    Abraham, Reem Rachel; Vashe, Asha; Torke, Sharmila

    2015-09-01

    The present study aimed to provide undergraduate medical students at Melaka Manipal Medical College (Manipal Campus), Manipal University, in Karnataka, India, an opportunity to apply their knowledge in cardiovascular concepts to real-life situations. A group activity named "Heart Shots" was implemented for a batch of first-year undergraduate students (n = 105) at the end of a block (teaching unit). Students were divided into 10 groups each having 10-11 students. They were requested to make a video/PowerPoint presentation about the application of cardiovascular principles to real-life situations. The presentation was required to be of only pictures/photos and no text material, with a maximum duration of 7 min. More than 95% of students considered that the activity helped them to apply their knowledge in cardiovascular concepts to real-life situations and understand the relevance of physiology in medicine and to revise the topic. More than 90% of students agreed that the activity helped them to apply their creativity in improving their knowledge and to establish a link between concepts rather than learning them as isolated facts. Based on the feedback, we conclude that the activity was student centered and that it facilitated learning. Copyright © 2015 The American Physiological Society.

  9. Low Data Drug Discovery with One-Shot Learning.

    Science.gov (United States)

    Altae-Tran, Han; Ramsundar, Bharath; Pappu, Aneesh S; Pande, Vijay

    2017-04-26

    Recent advances in machine learning have made significant contributions to drug discovery. Deep neural networks in particular have been demonstrated to provide significant boosts in predictive power when inferring the properties and activities of small-molecule compounds (Ma, J. et al. J. Chem. Inf. 2015, 55, 263-274). However, the applicability of these techniques has been limited by the requirement for large amounts of training data. In this work, we demonstrate how one-shot learning can be used to significantly lower the amounts of data required to make meaningful predictions in drug discovery applications. We introduce a new architecture, the iterative refinement long short-term memory, that, when combined with graph convolutional neural networks, significantly improves learning of meaningful distance metrics over small-molecules. We open source all models introduced in this work as part of DeepChem, an open-source framework for deep-learning in drug discovery (Ramsundar, B. deepchem.io. https://github.com/deepchem/deepchem, 2016).

  10. Kinematic adjustments in the basketball jump shot against an opponent.

    Science.gov (United States)

    Rojas, F J; Cepero, M; Oña, A; Gutierrez, M

    2000-10-01

    The aim of this study was to analyse the adjustments in technique made by a basketball player when shooting against an opponent. The subjects used consisted of 10 professional basketball players of the Spanish First Division League. Three-dimensional motion analysis based on video recordings (50 Hz) was used to obtain the kinematic characteristics of basketball jump shots with and without an opponent. It was found that when performing against an opponent the release angle of the ball increased, the flight time was reduced and postural adjustments as determined by the angles at the knee and shoulder increased, all significantly. There were several other non-significant differences that helped to interpret the changes in technique imposed by the presence of an opponent. It was suggested that when shooting with an opponent, players attempted to release the ball more quickly and from a greater height. This strategy will lessen the chance of the opponent intercepting the ball. It was concluded that the differences noted in the technical execution of the skill had implications for practice. It was suggested that training would benefit from practice with an opponent for at least some of the time to condition players to the demands which they were more likely to meet in the game situation.

  11. Deep Semisupervised Zero-Shot Learning with Maximum Mean Discrepancy.

    Science.gov (United States)

    Zhang, Lingling; Liu, Jun; Luo, Minnan; Chang, Xiaojun; Zheng, Qinghua

    2018-03-22

    Due to the difficulty of collecting labeled images for hundreds of thousands of visual categories, zero-shot learning, where unseen categories do not have any labeled images in training stage, has attracted more attention. In the past, many studies focused on transferring knowledge from seen to unseen categories by projecting all category labels into a semantic space. However, the label embeddings could not adequately express the semantics of categories. Furthermore, the common semantics of seen and unseen instances cannot be captured accurately because the distribution of these instances may be quite different. For these issues, we propose a novel deep semisupervised method by jointly considering the heterogeneity gap between different modalities and the correlation among unimodal instances. This method replaces the original labels with the corresponding textual descriptions to better capture the category semantics. This method also overcomes the problem of distribution difference by minimizing the maximum mean discrepancy between seen and unseen instance distributions. Extensive experimental results on two benchmark data sets, CU200-Birds and Oxford Flowers-102, indicate that our method achieves significant improvements over previous methods.

  12. High-energy 4ω probe laser for laser-plasma experiments at Nova

    International Nuclear Information System (INIS)

    Glenzer, S.H.; Weiland, T.L.; Bower, J.; MacKinnon, A.J.; MacGowan, B.J.

    1999-01-01

    For the characterization of inertial confinement fusion plasmas, we implemented a high-energy 4ω probe laser at the Nova laser facility. A total energy of >50 J at 4ω, a focal spot size of order 100 μm, and a pointing accuracy of 100 μm was demonstrated for target shots. This laser provides intensities of up to 3x10 14 Wcm -2 and therefore fulfills high-power requirements for laser-plasma interaction experiments. The 4ω probe laser is now routinely used for Thomson scattering. Successful experiments were performed in gas-filled hohlraums at electron densities of n e >2x10 21 cm -3 which represents the highest density plasma so far being diagnosed with Thomson scattering. copyright 1999 American Institute of Physics

  13. High-intensity laser diagnostics for OMEGA EP

    International Nuclear Information System (INIS)

    Bromage, J.; Zuegel, J.D.; Bahk, S.W.; Vickery, D.S.; Waxer, L.J.; Irwin, D.; Bagnoud, V.; Boni, R.; Moore, M.D.; Jungquist, R.; Stoeckl, C.

    2006-01-01

    OMEGA EP (Extended Performance) is a new high-energy peta-watt laser system under construction at the University of Rochester's Laboratory for Laser Energetics. This paper describes our designs for two diagnostics critical to OMEGA EP's mission. The focal-spot diagnostic (FSD) is responsible for characterizing the focal spot of OMEGA EP's off-axis parabolic mirror at full energy. The ultrafast temporal diagnostic (UTD) is responsible for characterizing pulse shapes of full-energy target shots ranging in width from < 1 to 100 ps as well as setting the desired pulse width before the shot. These diagnostics will enable, for the first time, complete spatial and temporal characterization of the focus of a high-energy peta-watt laser at full energy. (authors)

  14. Balancing habitat delivery for breeding marsh birds and nonbreeding waterfowl: An integrated waterbird management and monitoring approach at Clarence Cannon National Wildlife Refuge, Missouri

    Science.gov (United States)

    Loges, Brian W.; Lyons, James E.; Tavernia, Brian G.

    2017-08-23

    The Clarence Cannon National Wildlife Refuge (CCNWR) in the Mississippi River flood plain of eastern Missouri provides high quality emergent marsh and moist-soil habitat benefitting both nesting marsh birds and migrating waterfowl. Staff of CCNWR manipulate water levels and vegetation in the 17 units of the CCNWR to provide conditions favorable to these two important guilds. Although both guilds include focal species at multiple planning levels and complement objectives to provide a diversity of wetland community types and water regimes, additional decision support is needed for choosing how much emergent marsh and moist-soil habitat should be provided through annual management actions.To develop decision guidance for balanced delivery of high-energy waterfowl habitat and breeding marsh bird habitat, two measureable management objectives were identified: nonbreeding Anas Linnaeus (dabbling duck) use-days and Rallus elegans (king rail) occupancy of managed units. Three different composite management actions were identified to achieve these objectives. Each composite management action is a unique combination of growing season water regime and soil disturbance. The three composite management actions are intense moist-soil management (moist-soil), intermediate moist-soil (intermediate), and perennial management, which idles soils disturbance (perennial). The two management objectives and three management options were used in a multi-criteria decision analysis to indicate resource allocations and inform annual decision making. Outcomes of the composite management actions were predicted in two ways and multi-criteria decision analysis was used with each set of predictions. First, outcomes were predicted using expert-elicitation techniques and a panel of subject matter experts. Second, empirical data from the Integrated Waterbird Management and Monitoring Initiative collected between 2010 and 2013 were used; where data were lacking, expert judgment was used. Also, a

  15. Real-Time, Single-Shot Temporal Measurements of Short Electron Bunches, Terahertz CSR and FEL Radiation

    CERN Document Server

    Berden, G; Van der Meer, A F G

    2005-01-01

    Electro-optic detection of the Coulomb field of electron bunches is a promising technique for single-shot measurements of the bunch length and shape in the sub-picosecond time domain. This technique has been applied to the measurement of 50 MeV electron bunches in the FELIX free electron laser, showing the longitudinal profile of single bunches of around 650 fs FWHM [Phys. Rev. Lett. 93, 114802 (2004)]. The method is non-destructive and real-time, and therefore ideal for online monitoring of the longitudinal shape of single electron bunches. At FELIX we have used it for real-time optimization of sub-picosecond electron bunches. Electro-optic detection has also been used to measure the electric field profiles of far-infrared (or terahertz) optical pulses generated by the relativistic electrons. We have characterised the far-infrared output of the free electron laser, and more recently, we have measured the temporal profile of terahertz optical pulses generated at one of the bending magnets.

  16. Initial source of microbunching instability studies in a free electron laser injector

    Directory of Open Access Journals (Sweden)

    S. Seletskiy

    2011-11-01

    Full Text Available We present the first experimental studies of the initial source of electron beam microbunching instability in a free electron laser (FEL injector. By utilizing for the studies a transform-limited laser pulse at the photocathode, we eliminated laser-induced microbunching at the National Synchrotron Light Source Source Development Laboratory (SDL. The detailed measurements of the resulting electron beam led us to conclude that, at SDL, microbunching arising from shot noise is not amplified to any significant level, thereby allowing us to set an upper limit on the initial modulation depth of microbunching arising from shot noise. Our analysis demonstrated that the only significant source of microbunching instability under normal operational conditions at SDL is the longitudinal modulation of the photocathode laser pulse. Our work shows that assuring a longitudinally smoothed photocathode laser pulse allows mitigating microbunching instability at a typical FEL injector with a moderate microbunching gain.

  17. Laser ion source with solenoid field

    International Nuclear Information System (INIS)

    Kanesue, Takeshi; Okamura, Masahiro; Fuwa, Yasuhiro; Kondo, Kotaro

    2014-01-01

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 10 11 , which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator

  18. Laser ion source with solenoid field

    Science.gov (United States)

    Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

    2014-11-01

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

  19. The Effect of Shot Peening on the Improvement of Fatigue Strength and Characteristics Fatigue Crack of the Aluminum Alloys

    International Nuclear Information System (INIS)

    Jeon, Hyun Bae; Lim, Man Bae; Park, Won Jo

    2007-01-01

    The purpose of this study is to investigate the effect of shot peening on the fatigue strength and fatigue life of two kinds of aluminum alloys. The fatigue strength behavior of aluminum alloys were estimated by the stress ratio and shot velocities. The fatigue life and strength increased with increasing the test shot velocity. However, at the shot velocity range between 50m/s and 70m/s, the compressive residual stress phenomena were observed in test conditions of different shot velocity. The optimal shot velocity is acquired by considering the peak values of the compressive residual stress, dislocations, brittle striation, slip, and fisheye on the fracture surface of test specimen. It was observed from the SEM observation on the deformed specimen that the brittle striation, fisheye were showed in the intergranular fracture structure boundaries at the this velocities. Therefore, fatigue strength and fatigue life would be considered that shot velocity has close relationship with the compressive residual stress

  20. The importance of reliability to the SunShot Initiative (Presentation Recording)

    Science.gov (United States)

    Jones-Albertus, Rebecca

    2015-09-01

    The U.S. Department of Energy's SunShot Initiative was launched in 2011 to make subsidy-free solar electricity cost competitive with conventional energy sources by the end of the decade. Research in reliability can play a major role in realizing the SunShot goal of 0.06/kWh. By improving photovoltaic module lifetime and reducing degradation rates, a system's lifetime energy output is increased. Increasing confidence in photovoltaic performance prediction can lower perceived investment risk and thus the cost of capital. Accordingly, in 2015, SunShot expects to award more than $40 million through its SunShot National Laboratory Multiyear Partnership (SuNLaMP) and Physics of Reliability: Evaluating Design Insights for Component Technologies in Solar (PREDICTS) 2 funding programs, for research into reliability topics such as determining acceleration factors, modeling degradation rates and failure mechanisms, improving predictive performance models, and developing new test methods and instrumentation.

  1. Characterization of Residual Stress in Shot Peened Al 7075 Alloy Using Surface Acoustic Wave

    International Nuclear Information System (INIS)

    Kim, Chung Seok; Kwun, Sook In; Kim, Yong Kwon; Park, Ik Keun

    2006-01-01

    The residual stress in shot-peened Al 7075 alloy was evaluated using surface acoustic wave (SAW). Shot peening was conducted to produce a variation in the residual stress with the depth below the surface under a shot velocity of 30 m/s. The SAW velocity was measured from the V(z) curve using a scanning acoustic microscopy (SAM). The Vickers hardness profile from the surface showed a significant work hardening near the surface layer with a thickness of about 0.25 mm. As the residual stress became more compressive, the SAW velocity increased, whereas as the residual stress became more tensile, the SAW velocity decreased. The variation in the SAW velocity through the shot peened surface layer was in good agreement with the distribution of the residual stress measured by X-ray diffraction technique

  2. Investigation of fatigue properties of shot peened and plasma nitrocarburized P/M FC0205 steel

    International Nuclear Information System (INIS)

    Basaran, Ali; Kurgan, Naci; Varol, Remzi

    2013-01-01

    One of the widely used powder metal materials in automotive industry, which is copper steel FC 0205 (Fe + 2% Cu + 0.5% C), was used in this study. The pressed samples has been prepared at the compression pressure of 680 MPa and sintered in conventional furnace at 1120 .deg. C for 30 minutes. The samples with 7 Mg/m 3 densities were used as fatigue and shot peening processes. Shot peening were applied with 20A and 32A and the others were not peened. Plasma nitrocarburizing process was performed at 555 .deg. C for 2 hours under 600-900 Pa pressure. Fatigue tests were conducted at room temperature on a rotating bending type fatigue test device. It was determined that shot peening should be used where increased fatigue strength is needed, and plasma nitrocarburizing should be preferred where surface hardness is required, and plasma nitrocarburizing after shot peening process is much more useful.

  3. Experimental Study on Fatigue Behaviour of Shot-Peened Open-Hole Steel Plates.

    Science.gov (United States)

    Wang, Zhi-Yu; Wang, Qing-Yuan; Cao, Mengqin

    2017-08-25

    This paper presents an experimental study on the fatigue behaviour of shot-peened open-hole plates with Q345 steel. The beneficial effects induced by shot peening on the fatigue life improvement are highlighted. The characteristic fatigue crack initiation and propagation modes of open-hole details under fatigue loading are revealed. The surface hardening effect brought by the shot peening is analyzed from the aspects of in-depth micro-hardness and compressive residual stress. The fatigue life results are evaluated and related design suggestions are made as a comparison with codified detail categories. In particular, a fracture mechanics theory-based method is proposed and demonstrated its validity in predicting the fatigue life of studied shot-peened open-hole details.

  4. SunShot 2030 for Photovoltaics (PV): Envisioning a Low-Cost PV Future

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Wesley J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Frew, Bethany A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagnon, Pieter J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, James [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zuboy, Jarrett; Woodhouse, Michael A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-10-01

    This presentation summarizes the findings from the report 'SunShot 2030 for Photovoltaics (PV): Envisioning a Low-cost PV Future.' This presentation was given as a webinar on September 26, 2017.

  5. Influence of the shot-peening treatment on the CRF gearing behaviour

    International Nuclear Information System (INIS)

    Molinie, D.; Lemaire, E.; Randrianarivo, L.; Dorier, C.

    1998-01-01

    Surface damage are observed in service on CRF case-hardened cases. Such damage is like surface fatigue which appears in the form of frosting and can come to a micro-spalling or even a spalling damage. Survey and studies realised on gears affected by such damage, led EDF and the manufacturer to search for appropriated solutions since 1985 (optimisation of the gear bottom profile, care of the grinding and the thermochemical processing, use of oils with higher viscosity). Simulations on a running wheel device can reproduce the meshing conditions on simplified specimen. The aim is to study the influence of residual stresses following a severe grinding and shot peening treatments. An empiric selection was realised among different shot peening treatments. Endurance tests are realised on case-hardened gears with or without shot-peening treatments. Compared with standard grinded gears, it appears that the shot-peening selected increases up to 40% the gear lifetime till extended spalling. (authors)

  6. SunShot Initiative: Making Solar Energy Affordable for All Americans (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2013-10-01

    Through SunShot, DOE supports efforts by private companies, universities, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour, making solar energy affordable for more American families and businesses.

  7. Automatic video shot boundary detection using k-means clustering and improved adaptive dual threshold comparison

    Science.gov (United States)

    Sa, Qila; Wang, Zhihui

    2018-03-01

    At present, content-based video retrieval (CBVR) is the most mainstream video retrieval method, using the video features of its own to perform automatic identification and retrieval. This method involves a key technology, i.e. shot segmentation. In this paper, the method of automatic video shot boundary detection with K-means clustering and improved adaptive dual threshold comparison is proposed. First, extract the visual features of every frame and divide them into two categories using K-means clustering algorithm, namely, one with significant change and one with no significant change. Then, as to the classification results, utilize the improved adaptive dual threshold comparison method to determine the abrupt as well as gradual shot boundaries.Finally, achieve automatic video shot boundary detection system.

  8. Shot Boundary Detection in Soccer Video using Twin-comparison Algorithm and Dominant Color Region

    Directory of Open Access Journals (Sweden)

    Matko Šarić

    2008-06-01

    Full Text Available The first step in generic video processing is temporal segmentation, i.e. shot boundary detection. Camera shot transitions can be either abrupt (e.g. cuts or gradual (e.g. fades, dissolves, wipes. Sports video is one of the most challenging domains for robust shot boundary detection. We proposed a shot boundary detection algorithm for soccer video based on the twin-comparison method and the absolute difference between frames in their ratios of dominant colored pixels to total number of pixels. With this approach the detection of gradual transitions is improved by decreasing the number of false positives caused by some camera operations. We also compared performances of our algorithm and the standard twin-comparison method.

  9. Diphtheria and the Vaccine (Shot) to Prevent It: Information for Parents

    Science.gov (United States)

    ... PARENTS | DISEASES and the VACCINES THAT PREVENT THEM | Diphtheria and the Vaccine (Shot) to Prevent It Last ... April 2017 The best way to protect against diphtheria is by getting the diphther ia-tet anus- ...

  10. Shot noise and electronic properties in the inversion-symmetric Weyl semimetal resonant structure

    Science.gov (United States)

    Yang, Yanling; Bai, Chunxu; Xu, Xiaoguang; Jiang, Yong

    2018-02-01

    Using the transfer matrix method, the authors combine the analytical formula with numerical calculation to explore the shot noise and conductance of massless Weyl fermions in the Weyl semimetal resonant junction. By varying the barrier strength, the structure of the junction, the Fermi energy, and the crystallographic angle, the shot noise and conductance can be tuned efficiently. For a quasiperiodic superlattice, in complete contrast to the conventional junction case, the effect of the disorder strength on the shot noise and conductance depends on the competition of classical tunneling and Klein tunneling. Moreover, the delta barrier structure is also vital in determining the shot noise and conductance. In particular, a universal Fano factor has been found in a single delta potential case, whereas the resonant structure of the Fano factor perfectly matches with the number of barriers in a delta potential superlattice. These results are crucial for engineering nanoelectronic devices based on this topological semimetal material.

  11. Time to Get Your Seasonal Flu Shot | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... page please turn JavaScript on. Feature: Flu Season Time to Get Your Seasonal Flu Shot Past Issues / ... able to infect others for an even longer time. How serious is the flu? Certain people are ...

  12. Precision Laser Annealing of Focal Plane Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Bender, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); DeRose, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Starbuck, Andrew Lea [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Verley, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jenkins, Mark W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    We present results from laser annealing experiments in Si using a passively Q-switched Nd:YAG microlaser. Exposure with laser at fluence values above the damage threshold of commercially available photodiodes results in electrical damage (as measured by an increase in photodiode dark current). We show that increasing the laser fluence to values in excess of the damage threshold can result in annealing of a damage site and a reduction in detector dark current by as much as 100x in some cases. A still further increase in fluence results in irreparable damage. Thus we demonstrate the presence of a laser annealing window over which performance of damaged detectors can be at least partially reconstituted. Moreover dark current reduction is observed over the entire operating range of the diode indicating that device performance has been improved for all values of reverse bias voltage. Additionally, we will present results of laser annealing in Si waveguides. By exposing a small (<10 um) length of a Si waveguide to an annealing laser pulse, the longitudinal phase of light acquired in propagating through the waveguide can be modified with high precision, <15 milliradian per laser pulse. Phase tuning by 180 degrees is exhibited with multiple exposures to one arm of a Mach-Zehnder interferometer at fluence values below the morphological damage threshold of an etched Si waveguide. No reduction in optical transmission at 1550 nm was found after 220 annealing laser shots. Modeling results for laser annealing in Si are also presented.

  13. Power balance on a multibeam laser

    Science.gov (United States)

    Sampat, S.; Kelly, J. H.; Kosc, T. Z.; Rigatti, A. L.; Kwiatkowski, J.; Donaldson, W. R.; Romanofsky, M. H.; Waxer, L. J.; Dean, R.; Moshier, R.

    2018-02-01

    Inertial confinement fusion (ICF) cryogenic experiments on the 60-beam OMEGA laser have strict requirements for the laser energy delivered on target to be power balanced in order to maximize target-irradiation uniformity. For OMEGA, this quantity (power balance) is inferred from measurements of the time-integrated energy and time-resolved, spatially integrated temporal profile of each of the 60 beams at the output of the laser. The work presented here proposes a general definition of power balance as measured at the laser output and discusses the conditions that are fundamental to achieving laser power balance. Power balance necessitates equal gain across all stages of amplification, equal net losses across each amplifier stage, equal frequency conversion (from 1053 nm to 351 nm) of all 60 beams, and equal beam path lengths (beam timing). Typical OMEGA ICF laser pulse shapes consist of one or more short (100-ps) "pickets" followed by a shaped "drive" pulse of 1 to 2 ns. For these experiments, power balance is assessed for the pickets and the drive independently, with the ultimate goal of achieving root-mean-square (rms) imbalance across all 60 beams of less than 2% rms on both. This work presents a comprehensive summary of laser shot campaigns conducted to significantly improve laser power balance from typical rms values of 4.7% and 5.2%, respectively, to the 3% level for both features along with a discussion of future work required to further reduce the rms power imbalance of the laser system.

  14. Berry phase and shot noise for spin-polarized and entangled electrons

    International Nuclear Information System (INIS)

    Wang Pei; Tang Weihua; Lu Dinghui; Jiang Lixia; Zhao Xuean

    2007-01-01

    Shot noise for entangled and spin-polarized states in a four-probe geometric setup has been studied by adding two rotating magnetic fields in an incoming channel. Our results show that the noise power oscillates as the magnetic fields vary. The singlet, entangled triplet and polarized states can be distinguished by adjusting the magnetic fields. The Berry phase can be derived by measuring the shot noise power

  15. Kinematic Differences between Set- and Jump-Shot Motions in Basketball

    OpenAIRE

    Hiroki Okubo; Mont Hubbard

    2018-01-01

    Shooting arm motions at release in one-hand set and jump basketball shots have been analyzed using a kinematic model. Set and jump shots are classified by the vertical velocity and acceleration of the shooter’s shooting-side shoulder at release. The two-dimensional three-segment model includes the vertical shooting-side shoulder velocity and acceleration. Numerical simulation investigates the effect of shoulder motion. Release backspin angular velocity can be described as a function of the ve...

  16. Demonstration of the synchrotron-type spectrum of laser-produced Betatron radiation

    International Nuclear Information System (INIS)

    Fourmaux, S; Leguay, P M; Payeur, S; Lassonde, P; Gnedyuk, S; Lebrun, G; Kieffer, J C; Corde, S; Ta Phuoc, K; Malka, V; Sebban, S; Rousse, A; Fourment, C

    2011-01-01

    Betatron x-ray radiation in laser-plasma accelerators is produced when electrons are accelerated and wiggled in the laser-wakefield cavity. This femtosecond source, producing intense x-ray beams in the multi-kiloelectronvolt (keV) range, has been observed at different interaction regimes using a high-power laser from 10 to 100 TW. However, none of the spectral measurements carried out were at sufficient resolution, bandwidth and signal-to-noise ratio to precisely determine the shape of spectra with a single laser shot in order to avoid shot-to-shot fluctuations. In this paper, the Betatron radiation produced using a 80 TW laser is characterized by using a single photon counting method. We measure in a single shot spectra from 8 to 21 keV with a resolution better than 350 eV. The results obtained are in excellent agreement with theoretical predictions and demonstrate the synchrotron-type nature of this radiation mechanism. The critical energy is found to be E c =5.6±1 keV for our experimental conditions. In addition, the features of the source at this energy range open up novel opportunities for applications in time-resolved x-ray science.

  17. Use and Perceptions of Caffeinated Energy Drinks and Energy Shots in Canada.

    Science.gov (United States)

    Wiggers, Danielle; Reid, Jessica L; White, Christine M; Hammond, David

    2017-12-01

    In Canada, energy drinks and energy shots are currently classified and regulated differently (food and drugs versus natural health products, respectively), on the assumption that they are used and perceived differently. The current study examined potential differences in use and perceptions of energy drinks and shots. An online survey was conducted in 2015 using a national commercial online panel of youth and young adults aged 12-24 years (n=2,040 retained for analysis in 2016). Participants were randomized to view an image of an energy shot or drink, and were asked about 14 potential reasons for using the product. Past consumption of each product was also assessed. Chi-square and t-tests were conducted to examine differences in use and perceptions between products. Overall, 15.6% of respondents reported using both energy shots and drinks. Of all respondents, ordering of the reasons for use of each product was comparable. Despite differences in prevalence of ever-use of energy shots and drinks, consumption patterns and perceived reasons for using the products are similar. The findings provide little support for regulating energy shots differently than energy drinks. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  18. Shot-peening of carbonitrided steel: influence of the process on the mechanical state

    Directory of Open Access Journals (Sweden)

    François M.

    2010-06-01

    Full Text Available Residual stresses have a significant role in affecting engineering properties of materials and shot peening process is an effective production technique to ensure required residual stress levels. This paper presents an analysis of an orthogonal design of experiment to establish an empirical relationship between main parameters of shot peening process and residual stress profiles for a carbonitrided steel. The hardening / softening evolution of the material is followed using hardness and diffraction peak width. Four critical peening parameters, i.e. shot size, incident angle, exposure time, airblast pressure, have been chosen and the range of peening conditions are established by using the Taguchi technique. In this study, a shot velocity measurement system is used to obtain the on-line velocity during the peening process and the relationship between the maximum compressive residual stresses and the shot velocity is also developed. Analysis of the experimental data showed that it is possible to optimize the shot peening process by an effective control of process parameters.

  19. Shot noise in a toroidal carbon nanotube coupled with Majorana fermion states

    International Nuclear Information System (INIS)

    Zhang, Jian; Zhao, Hong-Kang; Wang, Qing

    2016-01-01

    Highlights: • The toroidal carbon nanotube interferometer coupled with Majorana fermions is considered. • The terminal current and shot noise have been investigated through equation of motion method. • The Andreev and cross-Andreev reflections contribute to the current and shot noise. • The enhancement of shot noise is generated by the application of Majorana fermions. • The periodic oscillations versus Aharonov–Bohm flux exhibit the controlling of Majorana fermions. - Abstract: The shot noise of a toroidal carbon nanotube (TCN) interferometer coupled with Majorana fermions is deduced from evaluating the current correlation. Many novel channels are opened for electrons to transport, and the energy gap of the semiconducting TCN becomes narrower. The Majorana fermions cause additional current correlations among the normal tunneling currents and Andreev reflection currents, and hence the shot noise and Fano factor are enhanced. The conductance, current, and shot noise are modified by Majorana fermions to exhibit different oscillation and resonance structures. The detailed behaviors of these quantities are quite different from the metal and semiconducting TCNs.

  20. Fatigue behavior of notched steel specimens with nanocrystallized surface obtained by severe shot peening

    International Nuclear Information System (INIS)

    Bagherifard, S.; Fernandez-Pariente, I.; Ghelichi, R.; Guagliano, M.

    2013-01-01

    Highlights: ► Steel notched specimens are shot peened using different peening parameters. ► Shot peening with severe parameters results in surface nanocrystallization. ► Severe treatment affects a thick layer of material by compressive residual stresses. ► Severe treatment results in a very significant fatigue strength improvement. -- Abstract: Among severe plastic deformation methods that result in surface nanocrystallization, shot peening has proved to be a promising technique. Application of severe air blast shot peening results in surface nanocrystallization, affects a thick layer of material with high compressive residual stresses but at the same time produces rather high surface roughness. In this study notched specimens with a stress concentration factor common in many structural components have been subjected to severe shot peening process. The mentioned treatment uses peening parameters essentially different from conventional ones. Roughness and X-ray diffraction residual stress measurements as well as microscopy observations have been carried out on the treated specimens. Room temperature rotating bending fatigue tests are performed to evaluate the effect of the treatment on specimens’ fatigue strength. Fracture surfaces have been then observed by scanning electron microscopy. The results indicate a very significant fatigue strength improvement for severely shot peened specimens in spite of their very high surface roughness.

  1. Microscopic analysis of effect of shot peening on corrosion fatigue behavior of aluminum alloy

    International Nuclear Information System (INIS)

    Kim, Jong Cheon; Cheong, Seong Kyun

    2012-01-01

    The object of this study considers corrosion fatigue improvement of 7075-T6 aluminum by using shot peening treatment on 3.5% NaCl solution at room temperature. Aluminum alloy is generally used in aerospace structural components because of the light weight and high strength characteristics. Many studies have shown that an aluminum alloy can be approximately 50% lighter than other materials. Mostly, corrosion leads to earlier fatigue crack propagation under tensile conditions and severely reduces the life of structures. Therefore, the technique to improve material resistance to corrosion fatigue is required. Shot peening technology is widely used to improve fatigue life and other mechanical properties by induced compressive residual stress. Even the roughness of treated surface causes pitting corrosion, the compressive residual stress, which is induced under the surface layer of material by shot peening, suppersses the corrosion and increases the corrosion resistance. The experimental results for shot peened specimens were compared with previous work for non treated aluminum alloy. The results show that the shot peening treatment affects the corrosion fatigue improvement of aluminum alloys and the induced compressive residual stress by shot peening treatment improves the resistance to corrosion fatigue

  2. A Study on the Microstructural Evolution of a Low Alloy Steel by Different Shot Peening Treatments

    Directory of Open Access Journals (Sweden)

    Juan González

    2018-03-01

    Full Text Available Recent studies have shown that severe shot peening can be categorized as a severe plastic deformation surface treatment that is able to strongly modify the microstructure of the surface layer of materials, by both increasing the dislocation density and introducing a large number of defects that define new grain boundaries and form ultrafine structure. In this work, conventional shot peening and severe shot peening treatments were applied to 39NiCrMo3 steel samples. The samples were characterized in terms of microstructure, surface roughness, microhardness, residual stresses, and surface work-hardening as a function of surface coverage. Particular attention was focused on the analysis of the microstructure to assess the evolution of grain size from the surface to the inner material to capture the gradient microstructure. Severe shot peening proved to cause a more remarkable improvement of the general mechanical characteristics compared to conventional shot peening; more significant improvement was associated with the microstructural alteration induced by the treatment. Our datas provide a detailed verification of the relationship between shot peening treatment parameters and the microstructure evolution from the treated surface to the core material.

  3. RELATIONSHIP OF KINEMATIC VARIABLES WITH THE PERFORMANCE OF BASKETBALLPLAYERS IN LAY-UP SHOT

    Directory of Open Access Journals (Sweden)

    Baljinder Singh Bal

    2009-10-01

    Full Text Available The purpose of the study was to determine the relationship between selected kinematic variables andperformance of lay-up shots. Five (N=5 male basketball players who represented Punjab Technical University,Jalandhar, were selected as subjects for the study. The help of digital photography was used to film the subjectsin sagittal plane of lay-up shot. Joint point method was used in order to obtain the values of selected angularkinematic variables from developed stick figures. Height of center of Gravity was calculated by segmentationmethod. The performance in Lay –Up Shot was recorded by the scores in Lay –Up Shot, which was obtained byusing a three point scale by the three judges. To determine the degree of relationship between selected kinematicvariables with the performance in Layup Shot, Pearson’s Product Moment Correlation Method was used. Theresults have shown the insignificant values of coefficient of correlation incase of all the selected kinematicvariables and significant relationship between the height of center of gravity at the moment of release with theperformance of the subjects in lay-up shots.

  4. Differential shot noise and Fano factor in a ferromagnet-Graphene-superconductor junction

    Science.gov (United States)

    Emamipour, Hamidreza

    2018-03-01

    Differential shot noise and Fano factor are investigated theoretically in a ferromagnet-Graphene-superconductor junctions, where ferromagnetism and superconductivity are induced by proximity effect, while the intermediate layer is Graphene. We have found that sub-gap region in shot noise and Fano factor is strongly affected by the ferromagnetic exchange energy. We have found that shot noise and Fano factor are suppressed when the exchange energy increases and the Andreev retro-reflection is the dominant process. When the dominant process is specular Andreev reflection, shot noise and Fano factor enhance by increasing the exchange energy. Also, for a wide intermediate Graphene layer, the shot noise oscillates vs applied bias voltage while there is no oscillation in the curves of Fano factor vs bias voltage. The calculation of Fano factor at zero bias shows that the Fano factor vs spin-polarization displays a clear distinction between Andreev retro-reflection and specular Andreev reflection. Our finding can be used not only to understand more about Andreev retro-reflection and specular Andreev reflection but also to discriminate between them through the differential shot noise and Fano factor.

  5. Kinematic Differences between Set- and Jump-Shot Motions in Basketball

    Directory of Open Access Journals (Sweden)

    Hiroki Okubo

    2018-02-01

    Full Text Available Shooting arm motions at release in one-hand set and jump basketball shots have been analyzed using a kinematic model. Set and jump shots are classified by the vertical velocity and acceleration of the shooter’s shooting-side shoulder at release. The two-dimensional three-segment model includes the vertical shooting-side shoulder velocity and acceleration. Numerical simulation investigates the effect of shoulder motion. Release backspin angular velocity can be described as a function of the vertical shoulder acceleration and the vertical fingertip acceleration relative to the shoulder. For proper backspin, jump shots require large vertical fingertip acceleration relative to the shoulder. The upward shoulder speed at release contributes to the vertical fingertip velocity relative to the shoulder for a given desired ball release speed, angle and backspin. On the other hand, upward shoulder motion does not contribute to the horizontal direction. As horizontal shot distance increases, upper arm angular speed also increases to produce the ball release conditions. Ball release with upward shoulder speed reduces the magnitudes of the upper arm, forearm and hand angular velocities. All these facts imply that the shooting arm motion in the jump shot is different from that of the set shot.

  6. Evaluation of the 1Shot Phantom dedicated to the mammography system using FCR

    International Nuclear Information System (INIS)

    Nagashima, Chieko; Uchiyama, Nachiko; Moriyama, Noriyuki; Nagata, Mio; Kobayashi, Hiroyuki; Sankoda, Katsuhiro; Saotome, Shigeru; Tagi, Masahiro; Kusunoki, Tetsurou

    2009-01-01

    Currently daily quality control (QC) tests for mammography systems are generally evaluated by using visual analysis phantoms, which of course means subjective measurement. In our study, however, we evaluated a novel digital phantom, the 1Shot Phantom M plus (1Shot Phantom), together with automatic analysis software dedicated for mammography systems using Fuji computed radiography (FCR). The digital phantom enables objective evaluation by providing for actual physical measurement rather than subjective visual assessment. We measured contrast to noise ratio (CNR), image receptor homogeneity, missed tissue at chest wall side, modulation transfer function (MTF), and geometric distortion utilizing the 1Shot Phantom. We then compared the values obtained using the 1Shot Phantom with values obtained from the European guidelines and International Electrotechnical Commission (IEC) standards. In addition, we evaluated the convenience of using the digital phantom. The values utilizing the 1Shot Phantom and those from the European guidelines and IEC standards were consistent, but the QC tests for the European guidelines and IEC standards methods took about six hours while the same QC tests using the 1Shot Phantom took 10 minutes or less including exposure of the phantom image, measurement, and analysis. In conclusion, the digital phantom and dedicated software proved very useful and produced improved analysis for mammography systems using FCR in clinical daily QC testing because of their objectivity and substantial time-saving convenience. (author)

  7. Quantitative single shot and spatially resolved plasma wakefield diagnostics

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Levy, Matthew C; Ratan, Naren; Sadler, James; Bingham, Robert; Burrows, Philip N; Trines, Raoul; Wing, Matthew; Norreys, Peter

    2015-01-01

    Diagnosing plasma conditions can give great advantages in optimizing plasma wakefield accelerator experiments. One possible method is that of photon acceleration. By propagating a laser probe pulse through a plasma wakefield and extracting the imposed frequency modulation, one can obtain an image of the density modulation of the wakefield. In order to diagnose the wakefield parameters at a chosen point in the plasma, the probe pulse crosses the plasma at oblique angles relative to the wakefield. In this paper, mathematical expressions relating the frequency modulation of the laser pulse and the wakefield density profile of the plasma for oblique crossing angles are derived. Multidimensional particle-in-cell simulation results presented in this paper confirm that the frequency modulation profiles and the density modulation profiles agree to within 10%. Limitations to the accuracy of the measurement are discussed in this paper. This technique opens new possibilities to quantitatively diagnose the plasma wakefie...

  8. Research on the laser angle deception jamming technology of laser countermeasure

    Science.gov (United States)

    Ma, Shi-wei; Chen, Wen-jian; Gao, Wei; Duan, Yuan-yuan

    2015-10-01

    In recent years , laser guided weapons behave very well at destroying the military goals in the local wars, the single-shot probability, effective range and hitting precision getting better. And the semi-active laser guided weapons are the most widely used laser guided weapons. In order to improve the viability and protect important military goals, it's necessary to study the technology to against the semi-active guided weapons. This paper studies the working principle, the advantages and disadvantages of the semi-active guided weapons at first, and analyze the possibility of laser angle deception jamming system working. Then it analyzes the working principle and process of laser angle deception jamming technology. Finally it designs a half-real simulation system of laser angle deception jamming, which consists of semi-active laser guided weapons simulation system and laser angle deception jamming system. The simulation system demonstrates the working process of the laser angle deception jamming system. This paper provides fundamental base for the research on the countermeasure technology of semi-active laser guided weapons.

  9. Picosecond high power laser systems and picosecond diagnostic technique in laser produced plasma

    International Nuclear Information System (INIS)

    Kuroda, Hiroto; Masuko, H.; Maekawa, Shigeru; Suzuki, Yoshiji; Sugiyama, Masaru.

    1979-01-01

    Highly repetitive, high power YAG and Glass laser systems have been developed and been successfully used for the studies of laser-plasma interactions. Various picosecond diagnostic techniques have been developed for such purposes in the regions from optical to X-ray frequency. Recently highly sensitive X-ray (1 - 10 KeV) streak camera for highly repetitive operations have been developed. Preliminary experiment shows the achievement of 28ps temporal resolution (100μm slit) and good sensitivity with detectable minimum number of 10E3-1KeV photons/shot/slit area. (author)

  10. A treatment planning study to assess the feasibility of laser-driven proton therapy using a compact gantry design

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Kerstin M., E-mail: kerstin.hofmann@lrz.tu-muenchen.de; Wilkens, Jan J. [Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, Ismaninger Str. 22, 81675 München, Germany and Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany); Masood, Umar [OncoRay National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, PF 41, 01307 Dresden (Germany); Pawelke, Joerg [OncoRay National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, PF 41, 01307 Dresden, Germany and Institute of Radiation Physics, Helmholtz-Zentrum Dresden - Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany)

    2015-09-15

    Purpose: Laser-driven proton acceleration is suggested as a cost- and space-efficient alternative for future radiation therapy centers, although the properties of these beams are fairly different compared to conventionally accelerated proton beams. The laser-driven proton beam is extremely pulsed containing a very high proton number within ultrashort bunches at low bunch repetition rates of few Hz and the energy spectrum of the protons per bunch is very broad. Moreover, these laser accelerated bunches are subject to shot-to-shot fluctuations. Therefore, the aim of this study was to investigate the feasibility of a compact gantry design for laser-driven proton therapy and to determine limitations to comply with. Methods: Based on a published gantry beam line design which can filter parabolic spectra from an exponentially decaying broad initial spectrum, a treatment planning study was performed on real patient data sets. All potential parabolic spectra were fed into a treatment planning system and numerous spot scanning proton plans were calculated. To investigate limitations in the fluence per bunch, the proton number of the initial spectrum and the beam width at patient entrance were varied. A scenario where only integer shots are delivered as well as an intensity modulation from shot to shot was studied. The resulting plans were evaluated depending on their dosimetric quality and in terms of required treatment time. In addition, the influence of random shot-to-shot fluctuations on the plan quality was analyzed. Results: The study showed that clinically relevant dose distributions can be produced with the system under investigation even with integer shots. For small target volumes receiving high doses per fraction, the initial proton number per bunch must remain between 1.4 × 10{sup 8} and 8.3 × 10{sup 9} to achieve acceptable delivery times as well as plan qualities. For larger target volumes and standard doses per fraction, the initial proton number is even

  11. Impact of environmental contamination on laser induced damage of silica optics in Laser MegaJoule; Impact de l'environnement sur l'endommagement laser des optiques de silice du Laser MegaJoule

    Energy Technology Data Exchange (ETDEWEB)

    Bien-Aime, K.

    2009-11-15

    Laser induced damage impact of molecular contamination on fused polished silica samples in a context of high power laser fusion facility, such as Laser MegaJoule (LMJ) has been studied. One of the possible causes of laser induced degradation of optical component is the adsorption of molecular or particular contamination on optical surfaces. In the peculiar case of LMJ, laser irradiation conditions are a fluence of 10 J/cm{sup 2}, a wavelength of 351 nm, a pulse duration of 3 ns for a single shot/days frequency. Critical compounds have been identified thanks to environmental measurements, analysis of material outgassing, and identification of surface contamination in the critical environments. Experiments of controlled contamination involving these compounds have been conducted in order to understand and model mechanisms of laser damage. Various hypotheses are proposed to explain the damage mechanism. (author)

  12. Fabrication and subband gap optical properties of silicon supersaturated with chalcogens by ion implantation and pulsed laser melting

    International Nuclear Information System (INIS)

    Bob, Brion P.; Aziz, Michael J.; Kohno, Atsushi; Charnvanichborikarn, Supakit; Williams, James S.; Warrender, Jeffrey M.; Umezu, Ikurou; Tabbal, Malek

    2010-01-01

    Topographically flat, single crystal silicon supersaturated with the chalcogens S, Se, and Te was prepared by ion implantation followed by pulsed laser melting and rapid solidification. The influences of the number of laser shots on the atomic and carrier concentration-depth profiles were measured with secondary ion mass spectrometry and spreading resistance profiling, respectively. We found good agreement between the atomic concentration-depth profiles obtained from experiments and a one-dimensional model for plane-front melting, solidification, liquid-phase diffusion, with kinetic solute trapping, and surface evaporation. Broadband subband gap absorption is exhibited by all dopants over a wavelength range from 1 to 2.5 microns. The absorption did not change appreciably with increasing number of laser shots, despite a measurable loss of chalcogen and of electronic carriers after each shot.

  13. CO2 TEA Laser-Enhanced Laser Ablation Molecular Isotopic Spectrometry (TELLAMIS)

    Science.gov (United States)

    Brown, Staci R.; Akpovo, Charlemagne A.; Ford, Alan; Herbert, Kenley; Johnson, Lewis

    2014-03-01

    Recently, it has been shown that the relative abundance of isotopes in enriched materials can be determined via laser-induced breakdown spectroscopy (LIBS) in a technique known as laser-ablation molecular isotopic spectroscopy (LAMIS). The original LAMIS work has focused on single-pulse (SP) LIBS for the excitation. However, dual-pulse (DP) LIBS reduces shot-to-shot variation and can lower detection limits of an element by about an order of magnitude or more. It also has the potential to improve the accuracy of the determination of the relative abundances of isotopes in LAMIS by minimizing the signal-to-noise ratio. In this work, a DP-LIBS technique for improving LAMIS relative-abundance information from a sample is presented. The new technique, called (TEA) Transverse-Excited breakdown in Atmosphere Laser-Enhanced Laser Ablation Molecular Isotopic Spectrometry (TELLAMIS), uses a carbon dioxide (CO2) laser to increase the breakdown emission from LIBS in the LAMIS method. This technique is demonstrated on a collection of relative abundance isotopes of boron- 10 and boron-11 in varying concentrations in boric acid. Least-squares fitting to theoretical models are used to deduce plasma parameters and understand reproducibility of results. DTRA.

  14. Development of Compton X-ray spectrometer for high energy resolution single-shot high-flux hard X-ray spectroscopy

    International Nuclear Information System (INIS)

    Kojima, Sadaoki; Ikenouchi, Takahito; Arikawa, Yasunobu; Sakata, Shohei; Zhang, Zhe; Abe, Yuki; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke; Azechi, Hiroshi; Ozaki, Tetsuo; Miyamoto, Shuji; Yamaguchi, Masashi; Takemoto, Akinori

    2016-01-01

    Hard X-ray spectroscopy is an essential diagnostics used to understand physical processes that take place in high energy density plasmas produced by intense laser-plasma interactions. A bundle of hard X-ray detectors, of which the responses have different energy thresholds, is used as a conventional single-shot spectrometer for high-flux (>10 13 photons/shot) hard X-rays. However, high energy resolution (Δhv/hv < 0.1) is not achievable with a differential energy threshold (DET) X-ray spectrometer because its energy resolution is limited by energy differences between the response thresholds. Experimental demonstration of a Compton X-ray spectrometer has already been performed for obtaining higher energy resolution than that of DET spectrometers. In this paper, we describe design details of the Compton X-ray spectrometer, especially dependence of energy resolution and absolute response on photon-electron converter design and its background reduction scheme, and also its application to the laser-plasma interaction experiment. The developed spectrometer was used for spectroscopy of bremsstrahlung X-rays generated by intense laser-plasma interactions using a 200 μm thickness SiO 2 converter. The X-ray spectrum obtained with the Compton X-ray spectrometer is consistent with that obtained with a DET X-ray spectrometer, furthermore higher certainly of a spectral intensity is obtained with the Compton X-ray spectrometer than that with the DET X-ray spectrometer in the photon energy range above 5 MeV.

  15. Nanosecond laser damage investigations in nonlinear crystals

    International Nuclear Information System (INIS)

    Hildenbrand, A.

    2008-11-01

    Lasers become more and more powerful and compact. This raises laser induced damage issues in optical components, especially in nonlinear crystals. This thesis deals with nanosecond laser damage investigations in nonlinear crystals used for frequency conversion (KTP, KDP, LBO) and electro-optic applications (RTP, KDP). First, due to nonlinear and anisotropic effects of the crystals, the development of a metrology dedicated to laser damage studies of crystals was necessary. This metrology was then applied to the study of KTP and RTP isomorphous crystals, and LBO crystals. The influence of many parameters on the laser damage resistance, such as wavelength, polarization and crystal orientation, was studied allowing a better understanding of the laser damage phenomena in these crystals. Moreover, laser induced damage characterization was realized on these crystals with a high number of shots and in the real operating conditions, showing that the laser damage threshold of the component depends on its use. For example, the coexistence of multiple wavelengths inside the crystal takes a great part in the damage phenomena. (author)

  16. Optimization of a seeding option for the VUV free electron laser at DESY

    CERN Document Server

    Saldin, E L; Yurkov, M V

    2000-01-01

    In order to get fully coherent radiation from the Free Electron Laser (FEL) amplifier starting from the shot noise, it is foreseen to implement a seeding option into the VUV FEL being under construction at DESY (DESY print TESLA-FEL 95-03, Hamburg, DESY, 1995, Seeding option for the VUV free electron laser at DESY: joint DESY and GKSS proposal; Available at DESY upon request only). It consists of an additional undulator, a bypass for electrons and an X-ray monochromator. This paper presents the results of optimization of the seeding option for the VUV FEL providing maximal spectral brightness at minimal shot-to-shot intensity fluctuations. Calculations are performed with three-dimensional, time-dependent simulation code FAST (Nucl. Instr. and Meth. A 429 (1999) 233).

  17. Few-femtosecond time-resolved measurements of X-ray free-electron lasers.

    Science.gov (United States)

    Behrens, C; Decker, F-J; Ding, Y; Dolgashev, V A; Frisch, J; Huang, Z; Krejcik, P; Loos, H; Lutman, A; Maxwell, T J; Turner, J; Wang, J; Wang, M-H; Welch, J; Wu, J

    2014-04-30

    X-ray free-electron lasers, with pulse durations ranging from a few to several hundred femtoseconds, are uniquely suited for studying atomic, molecular, chemical and biological systems. Characterizing the temporal profiles of these femtosecond X-ray pulses that vary from shot to shot is not only challenging but also important for data interpretation. Here we report the time-resolved measurements of X-ray free-electron lasers by using an X-band radiofrequency transverse deflector at the Linac Coherent Light Source. We demonstrate this method to be a simple, non-invasive technique with a large dynamic range for single-shot electron and X-ray temporal characterization. A resolution of less than 1 fs root mean square has been achieved for soft X-ray pulses. The lasing evolution along the undulator has been studied with the electron trapping being observed as the X-ray peak power approaches 100 GW.

  18. Analysis of Indium Tin Oxide Film Using Argon Fluroide (ArF) Laser-Excited Atomic Fluorescence of Ablated Plumes.

    Science.gov (United States)

    Ho, Sut Kam; Garcia, Dario Machado

    2017-04-01

    A two-pulse laser-excited atomic fluorescence (LEAF) technique at 193 nm wavelength was applied to the analysis of indium tin oxide (ITO) layer on polyethylene terephthalate (PET) film. Fluorescence emissions from analytes were induced from plumes generated by first laser pulse. Using this approach, non-selective LEAF can be accomplished for simultaneous multi-element analysis and it overcomes the handicap of strict requirement for laser excitation wavelength. In this study, experimental conditions including laser fluences, times for gating and time delay between pulses were optimized to reveal high sensitivity with minimal sample destruction and penetration. With weak laser fluences of 100 and 125 mJ/cm 2 for 355 and 193 nm pulses, detection limits were estimated to be 0.10% and 0.43% for Sn and In, respectively. In addition, the relation between fluorescence emissions and number of laser shots was investigated; reproducible results were obtained for Sn and In. It shows the feasibility of depth profiling by this technique. Morphologies of samples were characterized at various laser fluences and number of shots to examine the accurate penetration. Images of craters were also investigated using scanning electron microscopy (SEM). The results demonstrate the imperceptible destructiveness of film after laser shot. With such weak laser fluences and minimal destructiveness, this LEAF technique is suitable for thin-film analysis.

  19. 3-D analysis of fatigue crack behaviour in a shot peened steam turbine blade material

    Energy Technology Data Exchange (ETDEWEB)

    He, B.Y., E-mail: Binyan.he@soton.ac.uk [Engineering Materials, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Katsamenis, O.L. [muVIS X-ray Imaging Centre, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Mellor, B.G.; Reed, P.A.S. [Engineering Materials, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2015-08-26

    Serial mechanical sectioning and high resolution X-ray tomography have been used to study the three-dimensional morphology of small fatigue cracks growing in a 12 Cr tempered martensitic steam turbine blade material. A range of surface conditions has been studied, namely polished and shot peened (with varying levels of intensity). In the polished (unpeened) condition, inclusions (alumina and manganese sulphide) played an important role in initiating and controlling early fatigue crack behaviour. When fatigue cracks initiated from an alumina stringer, the crack morphology was normally dominated by single stringers, which were always in the centre of the fatigue crack, indicating its primary role in initiation. Manganese sulphide inclusion groups however seemed to dominate and affect the crack path along both the surface and depth crack growth directions. The more intensely shot peened condition did not however evidence inclusion or stringer affected fatigue crack initiation or growth behaviour; sub-surface crack coalescence being clearly observed by both serial sectioning and computed tomography (CT) imaging techniques at a depth of about 150–180 μm. These sub-surface crack coalescences can be linked to both the extent of the compressive residual stress as well as the depth of the plastic deformation arising from the intense shot peening process. Shot peening appears to provide a different defect population that initiates fatigue cracks and competes with the underlying metallurgical defect populations. The most beneficial shot peening process would in this case appear to “deactivate” the original metallurgical defect population and substitute a known defect distribution from the shot peening process from which fatigue cracks grow rather slowly in the strain hardened surface layer which also contains compressive residual stresses. A benefit to fatigue life in bending, even under Low Cycle Fatigue (LCF) conditions, has been observed in these tests if a

  20. 3-D analysis of fatigue crack behaviour in a shot peened steam turbine blade material

    International Nuclear Information System (INIS)

    He, B.Y.; Katsamenis, O.L.; Mellor, B.G.; Reed, P.A.S.

    2015-01-01

    Serial mechanical sectioning and high resolution X-ray tomography have been used to study the three-dimensional morphology of small fatigue cracks growing in a 12 Cr tempered martensitic steam turbine blade material. A range of surface conditions has been studied, namely polished and shot peened (with varying levels of intensity). In the polished (unpeened) condition, inclusions (alumina and manganese sulphide) played an important role in initiating and controlling early fatigue crack behaviour. When fatigue cracks initiated from an alumina stringer, the crack morphology was normally dominated by single stringers, which were always in the centre of the fatigue crack, indicating its primary role in initiation. Manganese sulphide inclusion groups however seemed to dominate and affect the crack path along both the surface and depth crack growth directions. The more intensely shot peened condition did not however evidence inclusion or stringer affected fatigue crack initiation or growth behaviour; sub-surface crack coalescence being clearly observed by both serial sectioning and computed tomography (CT) imaging techniques at a depth of about 150–180 μm. These sub-surface crack coalescences can be linked to both the extent of the compressive residual stress as well as the depth of the plastic deformation arising from the intense shot peening process. Shot peening appears to provide a different defect population that initiates fatigue cracks and competes with the underlying metallurgical defect populations. The most beneficial shot peening process would in this case appear to “deactivate” the original metallurgical defect population and substitute a known defect distribution from the shot peening process from which fatigue cracks grow rather slowly in the strain hardened surface layer which also contains compressive residual stresses. A benefit to fatigue life in bending, even under Low Cycle Fatigue (LCF) conditions, has been observed in these tests if a

  1. Optimum laser intensity for the production of energetic deuterium ions from laser-cluster interaction

    Energy Technology Data Exchange (ETDEWEB)

    Bang, W.; Dyer, G.; Quevedo, H. J.; Bernstein, A. C.; Gaul, E.; Rougk, J.; Aymond, F.; Donovan, M. E.; Ditmire, T. [Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712 (United States)

    2013-09-15

    We measured, using Petawatt-level pulses, the average ion energy and neutron yield in high-intensity laser interactions with molecular clusters as a function of laser intensity. The interaction volume over which fusion occurred (1–10 mm{sup 3}) was larger than previous investigations, owing to the high laser power. Possible effects of prepulses were examined by implementing a pair of plasma mirrors. Our results show an optimum laser intensity for the production of energetic deuterium ions both with and without the use of the plasma mirrors. We measured deuterium plasmas with 14 keV average ion energies, which produced 7.2 × 10{sup 6} and 1.6 × 10{sup 7} neutrons in a single shot with and without plasma mirrors, respectively. The measured neutron yields qualitatively matched the expected yields calculated using a cylindrical plasma model.

  2. Optimum laser intensity for the production of energetic deuterium ions from laser-cluster interaction

    Science.gov (United States)

    Bang, W.; Dyer, G.; Quevedo, H. J.; Bernstein, A. C.; Gaul, E.; Rougk, J.; Aymond, F.; Donovan, M. E.; Ditmire, T.

    2013-09-01

    We measured, using Petawatt-level pulses, the average ion energy and neutron yield in high-intensity laser interactions with molecular clusters as a function of laser intensity. The interaction volume over which fusion occurred (1-10 mm3) was larger than previous investigations, owing to the high laser power. Possible effects of prepulses were examined by implementing a pair of plasma mirrors. Our results show an optimum laser intensity for the production of energetic deuterium ions both with and without the use of the plasma mirrors. We measured deuterium plasmas with 14 keV average ion energies, which produced 7.2 × 106 and 1.6 × 107 neutrons in a single shot with and without plasma mirrors, respectively. The measured neutron yields qualitatively matched the expected yields calculated using a cylindrical plasma model.

  3. Laser targets: introduction

    International Nuclear Information System (INIS)

    Rosen, M.D.

    1985-01-01

    The laser target design group was engaged in three main tasks in 1984: (1) analyzing Novette implosion and hohlraum-scaling data, (2) planning for the first experiments on Nova, and (3) designing laboratory x-ray laser targets and experiments. The Novette implosion and hohlraum scaling data are mostly classified and are therefore not discussed in detail here. The authors achieved average final/initial pusher pr ratios of about 50, some 3 times higher than the value achieved in the best Shiva shots. These pr values imply a fuel compression to 100 times liquid density, although this figure and other aspects of the experiments are subject to further interpretation because of detailed questions of target symmetry and stability. Their main long-term goal for Nova is to produce a so-called hydrodynamically equivalent target (HET) - that is, a target whose hydrodynamic behavior (implosion velocity, convergence ratio, symmetry and stability requirements, etc.) is very much like that of a high-gain target, but one that is scaled down in size to match the energy available from Nova and is too small to achieve enough hot-spot pr to ignite the cold, near-Fermi-degenerate fuel around it. Their goal for Nova's first year is to do experiments that will teach them how to achieve the symmetry and stability conditions required by an HET

  4. Metal surface nitriding by laser induced plasma

    Science.gov (United States)

    Thomann, A. L.; Boulmer-Leborgne, C.; Andreazza-Vignolle, C.; Andreazza, P.; Hermann, J.; Blondiaux, G.

    1996-10-01

    We study a nitriding technique of metals by means of laser induced plasma. The synthesized layers are composed of a nitrogen concentration gradient over several μm depth, and are expected to be useful for tribological applications with no adhesion problem. The nitriding method is tested on the synthesis of titanium nitride which is a well-known compound, obtained at present by many deposition and diffusion techniques. In the method of interest, a laser beam is focused on a titanium target in a nitrogen atmosphere, leading to the creation of a plasma over the metal surface. In order to understand the layer formation, it is necessary to characterize the plasma as well as the surface that it has been in contact with. Progressive nitrogen incorporation in the titanium lattice and TiN synthesis are studied by characterizing samples prepared with increasing laser shot number (100-4000). The role of the laser wavelength is also inspected by comparing layers obtained with two kinds of pulsed lasers: a transversal-excited-atmospheric-pressure-CO2 laser (λ=10.6 μm) and a XeCl excimer laser (λ=308 nm). Simulations of the target temperature rise under laser irradiation are performed, which evidence differences in the initial laser/material interaction (material heated thickness, heating time duration, etc.) depending on the laser features (wavelength and pulse time duration). Results from plasma characterization also point out that the plasma composition and propagation mode depend on the laser wavelength. Correlation of these results with those obtained from layer analyses shows at first the important role played by the plasma in the nitrogen incorporation. Its presence is necessary and allows N2 dissociation and a better energy coupling with the target. Second, it appears that the nitrogen diffusion governs the nitriding process. The study of the metal nitriding efficiency, depending on the laser used, allows us to explain the differences observed in the layer features

  5. Ion temperature measurement of a tokamak plasma by collective Thomson scattering of D2O laser radiation

    International Nuclear Information System (INIS)

    Behn, R.; Salito, S.A.; Siegrist, M.R.; Dicken, D.; Hackmann, J.

    1988-10-01

    A D 2 O FIR laser emitting 0.5 J in 1.4 μs at 385 μm and a heterodyne receiver system comprising a Schottky barrier diode mixer with a noise temperature of 8000 K (DSB) were used in a Thomson scattering experiment to measure the ion temperature of a tokamak plasma during a single laser shot. Series of measurements under reproducible plasma conditions have been carried out in H, D and He-plasmas. Their statistical analysis yielded a typical relative error of 25 % for a single shot measurement. (author) 9 figs., 2 tabs., 7 refs

  6. Next generation laser optics for a hybrid fusion-fission power plant

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, C J; Latkowski, J T; Schaffers, K I

    2009-09-10

    The successful completion of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL), followed by a campaign to achieve ignition, creates the proper conditions to begin exploring what development work remains to construct a power plant based on Inertial Confinement Fusion (ICF) technology. Fundamentally, two distinct NIF laser properties must be overcome. The repetition rate must increase from a shot every four hours to several shots per second. Additionally, the efficiency of converting electricity to laser light must increase by 20x to roughly 10 percent. Solid state diode pumped lasers, commercially available for table top applications, have adequate repetition rates and power conversion efficiencies, however, they operate at a tiny fraction of the required energy for an ICF power plant so would need to be scaled in energy and aperture. This paper describes the optics and coatings that would be needed to support this type of laser architecture.

  7. THE EFFECT OF COURT LOCATION AND AVAILABLE TIME ON THE TACTICAL SHOT SELECTION OF ELITE SQUASH PLAYERS

    Directory of Open Access Journals (Sweden)

    Goran Vuckovic

    2013-03-01

    Full Text Available No previous research in squash has considered the time between shots or the proximity of the ball to a wall, which are two important variables that influence shot outcomes. The aim of this paper was to analyse shot types to determine the extent to which they are played in different court areas and a more detailed analysis to determine whether the time available had an influence on the shot selected. Ten elite matches, contested by fifteen of the world's top right handed squash players (age 27 ± 3.2, height 1.81 ± 0.06 m, weight 76.3 ± 3.7 kg, at the men's World Team Championships were processed using the SAGIT/Squash tracking system with shot information manually added to the system. Results suggested that shot responses were dependent upon court location and the time between shots. When these factors were considered repeatable performance existed to the extent that one of two shots was typically played when there was limited time to play the shot (< 1.20s. For example, it was clear that when players did not have a lot of time to hit the ball (low time i.e. < 1.06s, and mid time i.e. 1.06 - 1.20s in the front left corner close to the side wall, the crosscourt lob was used frequently (44.30% and 36.31% respectively whereas when there was more time this shot was seldom used (13.64%. Consequently variant and invariant behaviour were shown to exist in elite squash although for the first time it was suggested that the availability of time to play a shot contributed to which of these behaviours was evident. This analysis could be extended by adopting a case study approach to see how individual differences in strategy and tactics affect shot selections

  8. Feasibility of ultrasonic and eddy current methods for measurement of residual stress in shot peened metals

    International Nuclear Information System (INIS)

    Lavrentyev, Anton I.; Stucky, Paul A.; Veronesi, William A.

    2000-01-01

    Shot peening is a well-known method for extending the fatigue life of metal components by introducing compressive residual stresses near their surfaces. The capability to nondestructively evaluate the near surface residual stress would greatly aid the assurance of proper fatigue life in shot-peened components. This paper presents preliminary results from a feasibility study examining the use of ultrasonic and eddy current NDE methods for residual stress measurement in components where the stress has been introduced by shot peening. With an ultrasonic method, a variation of ultrasonic surface wave speed with shot peening intensity was measured. Near surface conductivity was measured by eddy current methods. Since the effective penetration depth of both methods employed is inversely related to the excitation frequency, by making measurements at different frequencies, each method has the potential to provide the stress-depth profile. Experiments were conducted on aluminum specimens (alloy 7075-T7351) peened within the Almen peening intensity range of 4C to 16C. The experimental results obtained demonstrate a correlation between peening intensity and Rayleigh wave velocity and between peening intensity and conductivity. The data suggests either of the methods may be suitable, with limitations, for detecting unsatisfactory levels of shot peening. Several factors were found to contribute to the measured responses: surface roughness, near surface plastic deformation (cold work) and residual stress. The contribution of each factor was studied experimentally. The feasibility of residual stress determination from the measured data is discussed

  9. Shot noise in a quantum dot system coupled with Majorana bound states

    Science.gov (United States)

    Chen, Qiao; Chen, Ke-Qiu; Zhao, Hong-Kang

    2014-08-01

    We investigate the spectral density of shot noise and current for the system of a quantum dot coupled to Majorana bound states (MBS) employing the nonequilibrium Green’s function. The Majorana bound states at the end of the wire strongly affect the shot noise. There are two types of coupling in the system: dot-MBS and MBS-MBS coupling. The curves of shot noise and current versus coupling strength have novel steps owing to the energy-level splitting caused by dot-MBS coupling. The magnitude of these steps increases with the strength of dot-MBS coupling λ but decreases with the strength of MBS-MBS coupling. The steps shift toward the large ∣eV∣ region as λ or ɛM increases. In addition, dot-MBS coupling enhances the shot noise while MBS-MBS coupling suppresses the shot noise. In the absence of MBS-MBS coupling, a sharp jump emerges in the curve of the Fano factor at zero bias owing to the differential conductance being reduced by a factor of 1/2. This provides a novel technique for the detection of Majorana fermions.

  10. Development of an underwater shot peening system to prevent stress corrosion cracking of reactor internals

    International Nuclear Information System (INIS)

    Obata, M.; Kimura, M.; Shima, S.; Kanno, M.

    1998-01-01

    The water projection type shot peening system and remotely driven robots were developed to be operated under water, in order to apply shot peening to reactor internals (shroud) in boiling water reactors (BWRs). The effects of processing parameters on the residual stress depth profiles were examined to obtain the optimum processing conditions to suppress stress corrosion cracking (SCC). Creviced bent beam (CBB) type stress corrosion tests showed that the SCC resistance in Type 304 stainless steel was remarkable increased by the shot peening. It was ascertained by several fundamental experiments that the shot peening had no detrimental effects on the other material characteristics and had sufficient applicability to the practical shroud. The reliable processing system which the accelerated shots by the pressurized water could be supplied, completely sucked and repeatedly used in order to reduce radioactive waste was developed. Two types of remote handling robots were also developed to positioning to follow the complicated shape of the core shroud welds, and for processing efficiency by reducing radiation exposure , one for processing the inner surface of the cylindrical core shroud, and the other for processing the outer surface in the narrow annulus region. The system and robots were successfully applied to the core shrouds of Hamaoka Unit- 1 and Unit-2 of Chubu Electric Power Co., Ltd. (author)

  11. Effect of Shot Peening on Tribological Behaviors of Molybdenum-Thermal Spray Coating using HVOF Method

    Directory of Open Access Journals (Sweden)

    H. Mohassel

    2017-03-01

    Full Text Available We have investigated the influence of post-shot peening on Mo-coating as compared to substrate steel 16MnCr5 (according to ZFN-413 A. Shot peening of carburized steel discs with and without Mo-coating was performed by using Shot size S230, Almen intensity 0.42 mm ’A’ and exposure time 96 sec. Tribological properties were analyzed, using pin-on-disc tribometer apparatus, under dry sliding conditions at different specific applied loads, sliding velocities and distance. Typical standardized methods were used for studying of surface integrity parameters (micro-hardness, topography and surface roughness. Surface morphology of the Mo-coating specimens with and without Shot Peening before and after wear was evaluated by Scanning Electron Microscopy. The results showed that shot peening after Mo-coating has considerable effect on improving wear resistance and because of having low friction coefficient has showed better wear behavior and tribologi cal properties over that of the un-peened Mo-coating.

  12. Numerical simulation of the shot peening process under previous loading conditions

    International Nuclear Information System (INIS)

    Romero-Ángeles, B; Urriolagoitia-Sosa, G; Torres-San Miguel, C R; Molina-Ballinas, A; Benítez-García, H A; Vargas-Bustos, J A; Urriolagoitia-Calderón, G

    2015-01-01

    This research presents a numerical simulation of the shot peening process and determines the residual stress field induced into a component with a previous loading history. The importance of this analysis is based on the fact that mechanical elements under shot peening are also subjected to manufacturing processes, which convert raw material into finished product. However, material is not provided in a virgin state, it has a previous loading history caused by the manner it is fabricated. This condition could alter some beneficial aspects of the residual stress induced by shot peening and could accelerate the crack nucleation and propagation progression. Studies were performed in beams subjected to strain hardening in tension (5ε y ) before shot peening was applied. Latter results were then compared in a numerical assessment of an induced residual stress field by shot peening carried out in a component (beam) without any previous loading history. In this paper, it is clearly shown the detrimental or beneficial effect that previous loading history can bring to the mechanical component and how it can be controlled to improve the mechanical behavior of the material

  13. Analysis of Signal-to-Noise Ratio of the Laser Doppler Velocimeter

    DEFF Research Database (Denmark)

    Lading, Lars

    1973-01-01

    The signal-to-shot-noise ratio of the photocurrent of a laser Doppler anemometer is calculated as a function of the parameters which describe the system. It is found that the S/N is generally a growing function of receiver area, that few large particles are better than many small ones, and that g...

  14. Laser Pointers: Low-Cost, Low-Tech Innovative, Interactive Instruction Tool

    Science.gov (United States)

    Zdravkovska, Nevenka; Cech, Maureen; Beygo, Pinar; Kackley, Bob

    2010-01-01

    This paper discusses the use of laser pointers at the Engineering and Physical Sciences Library, University of Maryland, College Park, as a personal response system (PRS) tool to encourage student engagement in and interactivity with one-shot, lecture-based information literacy sessions. Unlike more sophisticated personal response systems like…

  15. Angle-resolved spectral Fabry-Pérot interferometer for single-shot measurement of refractive index dispersion over a broadband spectrum

    Science.gov (United States)

    Dong, J. T.; Ji, F.; Xia, H. J.; Liu, Z. J.; Zhang, T. D.; Yang, L.

    2018-01-01

    An angle-resolved spectral Fabry-Pérot interferometer is reported for fast and accurate measurement of the refractive index dispersion of optical materials with parallel plate shape. The light sheet from the wavelength tunable laser is incident on the parallel plate with converging angles. The transmitted interference light for each angle is dispersed and captured by a 2D sensor, in which the rows and the columns are used to simultaneously record the intensities as a function of wavelength and incident angle, respectively. The interferogram, named angle-resolved spectral intensity distribution, is analyzed by fitting the phase information instead of finding the fringe peak locations that present periodic ambiguity. The refractive index dispersion and the physical thickness can be then retrieved from a single-shot interferogram within 18 s. Experimental results of an optical substrate standard indicate that the accuracy of the refractive index dispersion is less than 2.5  ×  10-5 and the relative uncertainty of the thickness is 6  ×  10-5 mm (3σ) due to the high stability and the single-shot measurement of the proposed system.

  16. Almen intensity effect on microstructure and mechanical properties of low carbon steel subjected to severe shot peening

    International Nuclear Information System (INIS)

    Unal, Okan; Varol, Remzi

    2014-01-01

    This paper discusses alteration of microstructure and mechanical properties of low carbon steel after severe shot peening process. An ultra fine grained surface layer was formed on AISI 1017 mild steel by means of severe shot peening process. Surface characteristics were affirmed using optical microscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Nano hardness measurements were taken along the depth from shot peened surface using nanoindentation methods. The results showed that severe (unconventional) air blast shot peening process is an effective way to obtain ultra fine grained surface layer and to obtain superior mechanical properties.

  17. Regular self-microstructuring on CR39 using high UV laser dose

    International Nuclear Information System (INIS)

    Parvin, P.; Refahizadeh, M.; Mortazavi, S.Z.; Silakhori, K.; Mahdiloo, A.; Aghaii, P.

    2014-01-01

    The UV laser induced replicas in the form of self-lining microstructures are created by high dose (with high fluence) ArF laser irradiation on CR39. Microstructures as the self-induced contours, in the form of concentric circles, appear when the laser fluence is well above the ablation threshold. It leads to the regular periodic parallel lines, i.e. circles with large radii having spatial separation 100–200 nm and line width 300–600 nm, where the number of shots increases to achieve higher UV doses. The surface wettability is also investigated after laser texturing to exhibit that a notable hydrophilicity takes place at high doses.

  18. The effect of femtosecond laser irradiation conditions on precipitation of silver nanoparticles in silicate glasses

    International Nuclear Information System (INIS)

    Zeng Huidan; Qiu Jianrong; Jiang Xiongwei; Zhu Congshan; Gan Fuxi

    2004-01-01

    We report the effect of femtosecond laser irradiation conditions on precipitation of silver nanoparticles in silicate glasses. Absorption spectra show that the intensity of the absorption peak due to the surface plasmon resonance of silver nanoparticles increases with increase of the light intensity of the laser beam, beam diameter in the focal plane, Rayleigh length of the focusing lens and shot number of the laser pulse. The position of the surface plasmon resonance peak remains constant regardless of the variation of the irradiation conditions. The influences of laser irradiation conditions on the size and spatial distribution of silver nanoparticles are discussed

  19. The Newest Laser Processing

    International Nuclear Information System (INIS)

    Lee, Baek Yeon

    2007-01-01

    This book mentions laser processing with laser principle, laser history, laser beam property, laser kinds, foundation of laser processing such as laser oscillation, characteristic of laser processing, laser for processing and its characteristic, processing of laser hole including conception of processing of laser hole and each material, and hole processing of metal material, cut of laser, reality of cut, laser welding, laser surface hardening, application case of special processing and safety measurement of laser.

  20. Double-shot MeV electron diffraction and microscopy

    Directory of Open Access Journals (Sweden)

    P. Musumeci

    2017-07-01

    Full Text Available In this paper, we study by numerical simulations a time-resolved MeV electron scattering mode where two consecutive electron pulses are used to capture the evolution of a material sample on 10 ps time scales. The two electron pulses are generated by illuminating a photocathode in a radiofrequency photogun by two short laser pulses with adjustable delay. A streak camera/deflecting cavity is used after the sample to project the two electron bunches on two well separated regions of the detector screen. By using sufficiently short pulses, the 2D spatial information from each snapshot can be preserved. This “double-shot” technique enables the efficient capture of irreversible dynamics in both diffraction and imaging modes. In this work, we demonstrate both modes in start-to-end simulations of the UCLA Pegasus MeV microscope column.

  1. Kinetics of proton transfer in a green fluorescent protein: A laser ...

    Indian Academy of Sciences (India)

    Unknown

    triggered by the UV laser shot through a photodiode; thus, the zero of time was deter- mined by the incoming laser flash. This instrument was calibrated by photoactivation of a solution containing 2 mM o-NBA and 1 µM of the fluorescent pH indicator fluorescein at pH 8 (figure 3). The pH jump-induced decrease in ...

  2. Anti-spoof touchless 3D fingerprint recognition system using single shot fringe projection and biospeckle analysis

    Science.gov (United States)

    Chatterjee, Amit; Bhatia, Vimal; Prakash, Shashi

    2017-08-01

    Fingerprint is a unique, un-alterable and easily collected biometric of a human being. Although it is a 3D biological characteristic, traditional methods are designed to provide only a 2D image. This touch based mapping of 3D shape to 2D image losses information and leads to nonlinear distortions. Moreover, as only topographic details are captured, conventional systems are potentially vulnerable to spoofing materials (e.g. artificial fingers, dead fingers, false prints, etc.). In this work, we demonstrate an anti-spoof touchless 3D fingerprint detection system using a combination of single shot fringe projection and biospeckle analysis. For fingerprint detection using fringe projection, light from a low power LED source illuminates a finger through a sinusoidal grating. The fringe pattern modulated because of features on the fingertip is captured using a CCD camera. Fourier transform method based frequency filtering is used for the reconstruction of 3D fingerprint from the captured fringe pattern. In the next step, for spoof detection using biospeckle analysis a visuo-numeric algorithm based on modified structural function and non-normalized histogram is proposed. High activity biospeckle patterns are generated because of interaction of collimated laser light with internal fluid flow of the real finger sample. This activity reduces abruptly in case of layered fake prints, and is almost absent in dead or fake fingers. Furthermore, the proposed setup is fast, low-cost, involves non-mechanical scanning and is highly stable.

  3. Near field flow characteristics of the Bjork-Shiley Monostrut valve in a modified single shot valve chamber.

    Science.gov (United States)

    Manning, Keefe B; Przybysz, T Michael; Fontaine, Arnold A; Tarbell, John M; Deutsch, Steven

    2005-01-01

    In certain mechanical heart valves, cavitation has been shown to develop during closure and rebound, leading to valve damage, blood damage, and strokes. Whereas it is uncertain what causes mechanical heart valve related strokes, some evidence suggests that stable bubbles may be the culprits. Previous work has indicated that vortex cavitation may contribute to stable bubble growth. Therefore, in an effort to understand the vortex cavitation, laser Doppler velocimetry data are collected in a plane parallel to and 3 mm away from the major orifice during closure and rebound of a Bjork-Shiley Monostrut mechanical heart valve. A modified single shot chamber is used that incorporates a more realistic near valve geometry than those used in previous studies. The results show the formation of a vortex during closure, which intensifies during rebound and dissipates during the final closing cycle. A regurgitant jet with mean velocities up to 3 m/s through the clearance gap of the valve provides energy to the vortex. During the final closing cycle, the vortex breaks up into asymmetrical, small scale flow patterns. This study provides further evidence that stable bubble formation may stem from the intense vortex cavitation occurring during valve closure and rebound.

  4. Beneficial effect of shot peening on steamside oxidation of 300-series austenitic steels: An electrochemical study

    Science.gov (United States)

    Bystrianský, Václav; Krausová, Aneta; Macák, Jan; Děd, Jiří; Eltai, Elsadig; Hamouda, Abdel Magid

    2018-01-01

    The formation of a protective oxide ensures the good corrosion resistance of austenitic steels in high temperature steam. However after long-term interaction even the protective oxide may tend to exfoliate and cause operational problems. With shot peening believed to be an effective method for mitigating steamside oxidation and exfoliation, we compared oxide layers formed on two materials: AISI 316H with a rugged untreated surface and Super304H with a shot-peened surface. In addition to conventional methods (SEM/EDS, Raman spectroscopy), Mott-Schottky analysis was used to characterize the oxide layers in order to determine the quality of the protective oxide. The oxides formed on Super 304H showed unexpected semiconducting behaviour with a significantly lower charge carrier density, thereby supporting the benefits of shot peening. Our findings extend the knowledge applicable to the design of more efficient coal-fired power plants.

  5. Duopoly Market Analysis within One-Shot Decision Framework with Asymmetric Possibilistic Information

    Directory of Open Access Journals (Sweden)

    Peijun Guo

    2010-12-01

    Full Text Available In this paper, a newly emerging duopoly market with a short life cycle is analyzed. The partially known information of market is characterized by the possibility distribution of the parameter in the demand function. Since the life cycle of the new product is short, how many products should be produced by two rival firms is a typical one-shot decision problem. Within the one-shot decision framework, the possibilistic Cournot equilibrium is obtained for the optimal production level of each firm in a duopoly market with asymmetrical possibilistic information. The analysis results show that the proposed approaches are reasonable for one-shot decision problems, which are extensively encountered in business and economics.

  6. Empirical modeling of shot peening parameters for welded austenitic stainless steel using grey relational analysis

    International Nuclear Information System (INIS)

    Singh, Lakhwinder; Aggarwal, M. L.; Khan, R. A.

    2012-01-01

    The attempt of this paper is to present an effective approach for the optimization of the shot peening process of welded AISI 304 austenitic stainless steel with multi performance characteristics using Grey relational analysis (GRA) based on Taguchi orthogonal array. Twenty-seven experimental runs are performed to determine best process parameters level. An analysis of variance (ANOVA) is carried out to identify significant peening parameters. The response tables are obtained for analyzing the optimal levels of shot peening parameters and major factors that affect the quality function. The multiple performance characteristics including tensile strength, surface hardness and surface roughness are the quality functions considered for the optimization. Further mathematical models are developed using regression analysis for the tensile strength, surface hardness and surface roughness. It will be very helpful to the engineers in deciding the levels of the shot peening parameters for desired performance characteristics

  7. Why a noninteracting model works for shot noise in fractional charge experiments

    Science.gov (United States)

    Feldman, D. E.; Heiblum, Moty

    2017-03-01

    A fractional quasiparticle charge is a manifestation of strong interactions in the fractional quantum Hall effect. Nevertheless, shot noise of quasiparticles is well described by a formula, derived for noninteracting charges. We explain the success of that formula by proving that in the limits of strong and weak backscattering it holds irrespectively of microscopic details in weakly and strongly interacting systems alike. The derivation relies only on principles of statistical mechanics. We also derive an approximate model-independent formula for shot noise in the regime of intermediate backscattering. The equation is numerically close to the standard "noninteracting" fitting formula but suggests a different physical interpretation of the experimental results. We verify our theoretical predictions with a shot-noise experiment at the filling factor 3 /5 .

  8. Two-shot point-diffraction interferometer with an unknown phase shift

    International Nuclear Information System (INIS)

    Bai, Fuzhong; Liu, Zhen; Bao, Xiaoyan

    2010-01-01

    On the basis of a modified Mach–Zehnder interferometer, this paper proposes a two-shot point-diffraction interferometer (PDI), by which two π-shifted interferograms are created according to the principle of half-wave loss and are simultaneously captured by a single CCD camera. After an arbitrary unknown phase shift is induced, a second and final shot captures these last two patterns. Then a novel algorithm based on statistical principles is developed to extract the actual phase shift and the wavefront phase from four interferograms. The combination of two required shots and a robust algorithm allows the proposed PDI to be implemented efficiently and accurately. Related simulation and experiments are conducted to prove the correctness of the proposed method

  9. Notes from the Field: 10 Short Lessons on One-Shot Instruction

    Directory of Open Access Journals (Sweden)

    Megan Oakleaf

    2012-12-01

    Full Text Available Librarians teach. It might not be what they planned to do when they entered the profession, or it may have been a secret hope all along. Either way, librarians teach, and one teaching scenario remains quintessential: the one-shot library instruction session. In recognition of the centrality of the “one-shot,” this article shares several authors' “notes from the field." The notes provide a range of strategies for developing pedagogically sound one-shot library instruction sessions, grouped loosely into three categories: planning, delivery, and integration. The authors offer these insights in their own words in hopes that other teaching librarians may benefit from their experiences.

  10. A Shot Number Based Approach to Performance Analysis in Table Tennis

    Directory of Open Access Journals (Sweden)

    Tamaki Sho

    2017-01-01

    Full Text Available The current study proposes a novel approach that improves the conventional performance analysis in table tennis by introducing the concept of frequency, or the number of shots, of each shot number. The improvements over the conventional method are as follows: better accuracy of the evaluation of skills and tactics of players, additional insights into scoring and returning skills and ease of understanding the results with a single criterion. The performance analysis of matches played at the 2012 Summer Olympics in London was conducted using the proposed method. The results showed some effects of the shot number and gender differences in table tennis. Furthermore, comparisons were made between Chinese players and players from other countries, what threw light on the skills and tactics of the Chinese players. The present findings demonstrate that the proposed method provides useful information and has some advantages over the conventional method.

  11. Clarifying beliefs underlying hunter intentions to support a ban on lead shot

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.; Doncarlos, Kathy

    2016-01-01

    Shot from hunting adds toxic lead to environments worldwide. Existing lead shot regulations have been instituted with little understanding of hunter beliefs and attitudes. This study applied the Theory of Reasoned Action, using a multilevel, multivariate approach, to clarify how positive and negative beliefs relate to attitudes about a ban on lead shot. Structure coefficients and commonality analysis were employed to further examine relationships between beliefs and attitudes. Results suggest that while both positive and negative outcomes influence attitudes, positive outcomes were more influential for supporters and negative beliefs for opposers. Management may need to focus on the results from hunters who indicated that they would be unlikely to support a ban, as these hunters include those who may actively oppose additional efforts to regulate lead.

  12. Numerical method for solving stochastic differential equations with Poissonian white shot noise.

    Science.gov (United States)

    Kim, Changho; Lee, Eok Kyun; Hänggi, Peter; Talkner, Peter

    2007-07-01

    We propose a numerical integration scheme to solve stochastic differential equations driven by Poissonian white shot noise. Our formula, which is based on an integral equation, which is equivalent to the stochastic differential equation, utilizes a discrete time approximation with fixed integration time step. We show that our integration formula approaches the Euler formula if the Poissonian noise approaches the Gaussian white noise. The accuracy and efficiency of the proposed algorithm are examined by studying the dynamics of an overdamped particle driven by Poissonian white shot noise in a spatially periodic potential. We find that the accuracy of the proposed algorithm only weakly depends on the parameters characterizing the Poissonian white shot noise; this holds true even if the limit of Gaussian white noise is approached.

  13. A Shot Number Based Approach to Performance Analysis in Table Tennis.

    Science.gov (United States)

    Tamaki, Sho; Yoshida, Kazuto; Yamada, Koshi

    2017-01-01

    The current study proposes a novel approach that improves the conventional performance analysis in table tennis by introducing the concept of frequency, or the number of shots, of each shot number. The improvements over the conventional method are as follows: better accuracy of the evaluation of skills and tactics of players, additional insights into scoring and returning skills and ease of understanding the results with a single criterion. The performance analysis of matches played at the 2012 Summer Olympics in London was conducted using the proposed method. The results showed some effects of the shot number and gender differences in table tennis. Furthermore, comparisons were made between Chinese players and players from other countries, what threw light on the skills and tactics of the Chinese players. The present findings demonstrate that the proposed method provides useful information and has some advantages over the conventional method.

  14. Shot noise of charge current in a quantum dot responded by rotating and oscillating magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hong-Kang, E-mail: zhaohonk@yahoo.com; Zou, Wei-Ke [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Chen, Qiao [Department of Maths and Physics, Hunan Institute of Engineering, Xiangtan 411104 (China)

    2014-09-07

    We have investigated the shot noise and Fano factor of the dynamic spin-polarized quantum dot under the perturbations of a rotating magnetic field (RMF), and an oscillating magnetic field (OMF) by employing the non-equilibrium Green's function approach. The shot noise is enhanced from sub-Poissonian to super-Poissonian due to the application of RMF and OMF, and it is controlled sensitively by the tilt angle θ of RMF. The magnitude of shot noise increases as the photon energy ℏω of OMF increases, and its valley eventually is reversed to peaks as the photon energy is large enough. Double-peak structure of Fano factor is exhibited as the frequency of OMF increases to cover a large regime. The Zeeman energy μ{sub 0}B{sub 0} acts as an effective gate bias to exhibit resonant behavior, and novel peak emerges associated with the applied OMF.

  15. Laser damage test bench for space optics

    Science.gov (United States)

    Riede, Wolfgang; Allenspacher, Paul

    2017-11-01

    At the German Aerospace Center in Stuttgart a laser damage test bench is run to evaluate damage thresholds of various optical components. The system setup is based on the current ISO standards 11254 [1-3] for single shot and multiple pulse operation. The laser damage test bench contains two repetitively pulsed laser sources, a Ti:Sapphire and a Nd:YAG laser, operating at wavelengths of 775 nm and 1064 nm, respectively. Harmonic wavelength converters to the visible spectral range are available. Both lasers are supplying the same damage testing rig. Online damage assessment techniques like sensitive scatter probe monitoring and video microscopy monitoring are used. The system is suited and has been tested extensively in the past for dielectric coated optics like beam turning mirrors, reflectors and windows, nonlinear optical components, semiconductors, and laser crystals. The damage test bench is located in a class 10,000 cleanroom environment under a laminar flowbox providing an additional isolation factor of >103. The tests can also be performed in sealed optical compartments in partial vacuum and under long term irradiation conditions. All experiments are supported by theoretical simulation of laser-material interactions, down to the sub-ps timescale [4].

  16. Charged particle and laser irradiation of selected materials

    Energy Technology Data Exchange (ETDEWEB)

    Svendsen, W.E.

    1996-11-01

    The main topics of the present thesis are the processes governing electronic sputtering of insulators and laser ablation of metals and insulators. The sputtering yield for electron bombardment of solid deuterium was investigated using quartz crystal microbalances as the measuring technique. The sputtering yield was measured with varying electron energy and deuterium film thickness. Laser ablation measurements of silver and nickel were carried out using a Nd:YAG laser. The effect of various experimental parameters such as background gas pressure (Ar, N{sub 2}), position of quartz crystals with respect to target position and the optimal number of laser shots for carrying out the experiments were investigated. The deposition rate was measured with varying laser wavelength and laser fluence. The angular distribution of the ablated material was measured for silver as well. A theoretical model based on the thermal properties of laser interaction with metals was applied in the initial phase of ablation. For the non-thermal processes governing laser interaction with the ablated plasma plume, a model developed by Phipps and Dreyfus was used to interpret the results. Laser ablation measurements of water-ice were carried using a Nitrogen laser. Attempts were made to measure the deposition rate for various the laser wavelengths and energies. (au) 8 tabs., 49 ills., 77 refs.

  17. Charged particle and laser irradiation of selected materials

    International Nuclear Information System (INIS)

    Svendsen, W.E.

    1996-11-01

    The main topics of the present thesis are the processes governing electronic sputtering of insulators and laser ablation of metals and insulators. The sputtering yield for electron bombardment of solid deuterium was investigated using quartz crystal microbalances as the measuring technique. The sputtering yield was measured with varying electron energy and deuterium film thickness. Laser ablation measurements of silver and nickel were carried out using a Nd:YAG laser. The effect of various experimental parameters such as background gas pressure (Ar, N 2 ), position of quartz crystals with respect to target position and the optimal number of laser shots for carrying out the experiments were investigated. The deposition rate was measured with varying laser wavelength and laser fluence. The angular distribution of the ablated material was measured for silver as well. A theoretical model based on the thermal properties of laser interaction with metals was applied in the initial phase of ablation. For the non-thermal processes governing laser interaction with the ablated plasma plume, a model developed by Phipps and Dreyfus was used to interpret the results. Laser ablation measurements of water-ice were carried using a Nitrogen laser. Attempts were made to measure the deposition rate for various the laser wavelengths and energies. (au) 8 tabs., 49 ills., 77 refs

  18. Proceedings of the Laser Issues for Electron RF Photoinjectors Workshop

    CERN Document Server

    Bolton, P

    2003-01-01

    The Linac Coherent Light Source (LCLS) proposed for SLAC is a SASE FEL designed to generate high brightness, coherent, ultrashort x-ray pulses. The injector of choice is the RF photoinjector, which is capable of producing suitably low emittance electron beams. It is well established that the performance of the SASE FEL depends critically on properties of the electron beam generated by the injector and therefore on the injector laser beam parameters. This workshop was established specifically to provide a forum for discussion of photoinjector laser systems. Laser design requirements and technical challenges common to RF photoinjectors were highlighted and some solutions were explored. This included not only details of laser systems but also those of laser-based diagnostics envisioned for monitoring ultrashort electron microbunches on a single shot basis. Sixty-one registrants representing twenty-three institutions from Italy, Germany, Japan and the United States attended. The program listing shows that the twe...

  19. MR imaging of laser-induced meniscal lesions

    International Nuclear Information System (INIS)

    Naegele, M.; Leunig, M.; Goetz, A.E.; Lumper, W.; Gamarra, F.; Brendel, W.; Lissner, J.

    1990-01-01

    This paper determines whether MR imaging is able to demonstrate smaller laser-induced meniscal lesions and how the surrounding medium affects their detectability. Nine bovine menisci were studied, with eight to 10 laser-induced lesions per meniscus. Three different lasers were used (ER-YAG, HO-YAG, and Excimer-XeCl); three hertz values were used for each laser system. MR imaging was performed at 1.0 T on a Siemens Magnetom imager and with an experimental Helmholtz surface coil; three-dimensional fast low-angle shot images were obtained (50 degrees flip angle, 1-mm sections, two data acquisitions). Each meniscus was examined in room air, in 0.9% NaCl, and in Gd-DTPA, without a change in position. All laser-induced lesions were histologically prepared, and all lesion sizes measured with a digital imaging system. MR examinations were evaluated blindly

  20. Laser cleaning of varnishes and contaminants on brass

    International Nuclear Information System (INIS)

    Mateo, M.P.; Ctvrtnickova, T.; Fernandez, E.; Ramos, J.A.; Yanez, A.; Nicolas, G.

    2009-01-01

    The capability of laser ablation to perform controlled cleaning of varnishes containing contaminants and paints used by restorers in artistic objects from brass samples while keeping unaltered the finish structure is demonstrated in this work. Adequate laser energy per pulse and number of laser shots required to perform a suitable cleaning by laser ablation have been optimized. The inspection of the samples before and after the cleaning process by optical microscopy and by Fourier transform infrared spectroscopy (FTIR) technique demonstrated that the finish structure of the surface was intact while the coatings were completely eliminated. Furthermore, a laser-induced plasma spectroscopy (LIBS)-based detection system was applied during the irradiation process for the analysis of the material removal and also for its monitoring

  1. Quasi-thermal noise and shot noise spectroscopy on a CubeSat in Earth's ionosphere

    Science.gov (United States)

    Maj, Ronald; Cairns, Iver H.

    2017-03-01

    We investigate the practicality of using quasi-thermal noise (QTN) and shot noise spectroscopy on a CubeSat in the Earth's ionosphere and constrain the satellite antenna length for optimal detection of these signals. The voltage spectra predicted for thermal Langmuir waves (QTN) and particle "shot noise" are modeled, and it is shown that the signals detected can provide two very good, independent, passive, in situ methods of measuring the plasma density and temperature in the ionosphere. The impact of the antenna potential ϕ is also discussed, and we show that the negative potential calculated for the ionosphere due to natural current flows has a significant impact on the voltage power level of the shot noise spectrum. The antenna configuration is also shown to play an important role in the shot noise, with a monopole configuration enhancing the spectrum significantly compared with a dipole. Antenna lengths on the order of 20-40 cm are found to be ideal for ionospheric plasma conditions, nicely matching CubeSat sizes and producing detectable thermal Langmuir waves and shot noise at the microvolt level. Further, with a continuous stream of data points at different latitudes and longitudes an orbiting CubeSat can produce a global picture for the ionospheric plasma density and temperature using QTN and shot noise signals. If implemented, especially in a constellation, these data would be more frequent and cover a much greater domain than current ground-based or single-satellite methods. This could lead to improved ionospheric models, such as the empirically based International Reference Ionosphere.

  2. Noise equivalent circuit of a semiconductor laser diode

    Science.gov (United States)

    Harder, C.; Margalit, S.; Yariv, A.; Katz, J.; Shacham, J.

    1982-01-01

    A small-signal model of a semiconductor laser is extended to include the effects of intrinsic noise by adding current and voltage noise sources. The current noise source represents the shot noise of carrier recombination, while the voltage noise source represents the random process of simulated emission. The usefulness of the noise equivalent circuit is demonstrated by calculating the modulation and noise characteristics of a current-driven diode as a function of bias current and frequency.

  3. Thermodynamics of nanocrystilline formation in surface layer of Hadfield steel by shot peening

    International Nuclear Information System (INIS)

    Yan Weilin; Fang Liang; Sun Kun; Xu Yunhua

    2007-01-01

    Conventional shot peening tests of Hadfield steel have shown that a nanostructured grains layer can be easily produced. Theoretically, nanostructure formation thermodynamics becomes an important issue to coarse grains transformating into nanocrystalline. In the present paper, thermodynamics of strain induced nanosized microstructure in Hadfield steel after shot peening was discussed based on Pringogine's nonequilibrium thermodynamics and Miedema semi-experimental theory. It was concluded that the difference of Gibbs free energy should be at least increased to 0.1380 kJ/mol in the alloy system by strain hardening, compared to the previous Gibbs energy before the treatment

  4. Shot Noise Suppression in a Quantum Point Contact with Short Channel Length

    International Nuclear Information System (INIS)

    Jeong, Heejun

    2015-01-01

    An experimental study on the current shot noise of a quantum point contact with short channel length is reported. The experimentally measured maximum energy level spacing between the ground and the first excited state of the device reached up to 7.5 meV, probably due to the hard wall confinement by using shallow electron gas and sharp point contact geometry. The two-dimensional non-equilibrium shot noise contour map shows noise suppression characteristics in a wide range of bias voltage. Fano factor analysis indicates spin-polarized transport through a short quantum point contact. (paper)

  5. Different intensities of basketball drills affect jump shot accuracy of expert and junior players

    Directory of Open Access Journals (Sweden)

    Giuseppe Marcolin

    2018-02-01

    Full Text Available Background In basketball a maximum accuracy at every game intensity is required while shooting. The aim of the present study was to investigate the acute effect of three different drill intensity simulation protocols on jump shot accuracy in expert and junior basketball players. Materials & Methods Eleven expert players (age 26 ± 6 yrs, weight 86 ± 11 kg, height 192 ± 8 cm and ten junior players (age 18 ± 1 yrs, weight 75 ± 12 kg, height 184 ± 9 cm completed three series of twenty jump shots at three different levels of exertion. Counter Movement Jump (CMJ height was also measured after each series of jump shots. Exertion’s intensity was induced manipulating the basketball drills. Heart rate was measured for the whole duration of the tests while the rating of perceived exertion (RPE was collected at the end of each series of shots. Results Heart rate and rating of perceived exertion (RPE were statistically different in the three conditions for both expert and junior players. CMJ height remained almost unchanged in both groups. Jump shot accuracy decreased with increasing drills intensity both in experts and junior players. Expert players showed higher accuracy than junior players for all the three levels of exertion (83% vs 64%, p < 0.001; 75% vs 57%, p < 0.05; 76% vs 60%, p < 0.01. Moreover, for the most demanding level of exertion, experts showed a higher accuracy in the last ten shots compared to the first ten shots (82% vs 70%, p < 0.05. Discussion Experts coped better with the different exertion’s intensities, thus maintaining a higher level of performance. The introduction of technical short bouts of high-intensity sport-specific exercises into skill sessions should be proposed to improve jump shot accuracy during matches.

  6. Inversion recovery single-shot TurboFLASH for assessment of myocardial infarction at 3 Tesla.

    Science.gov (United States)

    Bauner, Kerstin U; Muehling, Olaf; Wintersperger, Bernd J; Winnik, Eva; Reiser, Maximilian F; Huber, Armin

    2007-06-01

    The aim of the study was to assess the diagnostic accuracy of imaging myocardial infarction with a single-shot inversion recovery turbofast low-angle shot (SS IR turboFLASH) sequence at 3.0 Tesla in comparison with an established segmented inversion recovery turboFLASH sequence at 1.5 Tesla. Fifteen patients with myocardial infarction were examined at a 1.5 Tesla magnetic resonance (MR) System (Avanto, Siemens, Medical Solutions) and at a 3.0 Tesla MR system (TIM Trio, Siemens, Medical Solutions). Imaging delayed enhancement was started 15 minutes after application of contrast material. A SS IR turboFLASH was performed at 3.0 Tesla and compared with a segmented IR turboFLASH sequence at 1.5 and at 3.0 Tesla. The IR turboFLASH sequence at 1.5 Tesla served as reference method. Infarct volumes, contrast/noise ratio (CNR) of infarcted and normal myocardium were compared with the reference method. The Single-Shot IR turboFLASH technique allows imaging 9 slices during a single breath-hold. The CNR between infarction and normal myocardium of the reference method was 6.4 at 1.5 Tesla. The mean value of CNR of the IR turboFLASH sequence was 7.3 at 3.0 Tesla for the single-shot technique and 14.1 at 3.0 Tesla for the segmented technique. No significant difference was found for the CNR values of the reference technique at 1.5 Tesla and the single-shot technique at 3.0 Tesla, however for the comparison of the segmented technique at 1.5 and at 3 Tesla (P = 0.0001). The correlation coefficients of the infarct volumes, determined with the Single-Shot IR turboFLASH and the segmented IR turboFLASH technique at 3.0 compared with the reference method, were r = 0.95 (P < 0.0001) and r = 0.95 (P < 0.0001). The loss of CNR, which is caused by replacement of the segmented technique by the single-shot technique, is completely compensated by the approximately 2-fold CNR increase at the higher field strength. The IR turboFLASH technique at 3.0 Tesla IR can be used as a single-shot technique

  7. Mean first passage times of processes driven by white shot noise.

    Science.gov (United States)

    Laio, F; Porporato, A; Ridolfi, L; Rodriguez-Iturbe, I

    2001-03-01

    We consider mean first passage times in systems driven by white shot noise with exponentially distributed jump heights. Simple interpretable results are obtained and the linkage between those results and the steady-state probability density function of the process is presented. The virtual waiting-time or Takács process (constant losses) and the shot noise process with linear losses are analyzed in depth, along with a more complex process with useful implications for the modeling of the soil moisture dynamics in hydrology.

  8. Optimization of a jump shot rhythm at the junior level of basketball performance

    OpenAIRE

    Bazanov, Boriss; Rannama, Indrek; Sirel, Kersti

    2015-01-01

    The jump shot is one of the most frequently used methods of shooting in the modern basketball. For example in the Spanish league, it accounts for 41% of all points (Rojas et al., 2000). Based on the results of our previous research which enabled to determine the phase structure and create rhythm models of shooting in elite male basketball (Bazanov, 2001, 2014) the purpose of this study was to improve the shooting rhythm of jump shot performances of male under 20 years old basketball players. ...

  9. Different intensities of basketball drills affect jump shot accuracy of expert and junior players

    OpenAIRE

    Marcolin, Giuseppe; Camazzola, Nicola; Panizzolo, Fausto Antonio; Grigoletto, Davide; Paoli, Antonio

    2018-01-01

    Background In basketball a maximum accuracy at every game intensity is required while shooting. The aim of the present study was to investigate the acute effect of three different drill intensity simulation protocols on jump shot accuracy in expert and junior basketball players. Materials & Methods Eleven expert players (age 26 ± 6 yrs, weight 86 ± 11 kg, height 192 ± 8 cm) and ten junior players (age 18 ± 1 yrs, weight 75 ± 12 kg, height 184 ± 9 cm) completed three series of twenty jump shot...

  10. Residual stress assessment for shot peened nickel based superalloy by eddy current technique

    Science.gov (United States)

    Shen, Yuping

    Surface enhancement treatment by shot peening has been widely used in industrial applications, especially for aircraft engine components. Typical peening processes use small shots of a few hundred micrometer in diameter blasted on component surfaces, resulting in residual stress near the surface in the depth range of a few hundred micrometers nominally. Compressive surface residual stress is useful for improving crack initiation resistance that prolongs service life of the part. To implement this highly desirable maintenance strategy, an in-service nondestructive method is needed to monitor the residual stress state of parts periodically, so that appropriate maintenance actions can be taken when residual-stress protection is lost, by either replacing or re-treating the part. X-ray and neutron diffraction methods are the only two standard methods considered the most reliable. However, conventional XRD methods can achieve relatively low penetration depth (Neutron diffraction method has also a practical limitation in terms of its cost and resulting radioactivity. In this dissertation, we developed a swept high frequency eddy current (SHFEC) measurement methodology for conductivity characterization of shot peened nickel based alloys. A model-based, eddy current inversion method is presented and applied to the SHFEC data obtained from a series of shot peened nickel based alloys to determine the depth profiles of actual conductivity up to 400 mum below the samples' surfaces. By developing a modified piezo-resistivity theory that includes the effect of texture on stress-induced conductivity changes, the residual stress profile of a shot peened IN718 sample is obtained from eddy current data. The obtained residual stress depth profile agrees with that measured by the standard layer removal XRD method. Texture profile of the shot peened IN718 sample is demonstrated by an XRD partial pole figure and orientation image microscopy (OIM). A new procedure of analyzing

  11. Single-shot self-interference incoherent digital holography using off-axis configuration.

    Science.gov (United States)

    Hong, Jisoo; Kim, Myung K

    2013-12-01

    We propose a single-shot incoherent holographic imaging technique that adopts self-interference incoherent digital holography (SIDH) with slight tilt of the plane mirror in the optical configuration. The limited temporal coherence length of the illumination leads the guide-star hologram of the proposed system to have a Gaussian envelope of elliptical ring shape. The observation shows that the reconstruction by cross correlation with the guide-star hologram achieves better quality than the usual propagation methods. Experimentally, we verify that the hologram and 3D reconstruction can be implemented incoherently with the proposed single-shot off-axis SIDH.

  12. Deuteron-induced reactions generated by intense lasers for PET isotope production

    Science.gov (United States)

    Kimura, Sachie; Bonasera, Aldo

    2011-05-01

    We investigate the feasibility of using laser accelerated protons/deuterons for positron emission tomography (PET) isotope production by means of the nuclear reactions 11B(p, n) 11C and 10B(d, n) 11C. The second reaction has a positive Q-value and no energy threshold. One can, therefore, make use of the lower energy part of the laser-generated deuterons, which includes the majority of the accelerated deuterons. By assuming that the deuteron spectra are similar to the proton spectra, the 11C produced from the reaction 10B(d, n) 11C is estimated to be 7.4×10 9 per laser-shot at the Titan laser at Lawrence Livermore National Laboratory. Meanwhile a high-repetition table-top laser irradiation is estimated to generate 3.5×10 711C per shot from the same reaction. In terms of the 11C activity, it is about 2×10 4 Bq per shot. If this laser delivers kHz, the activity is integrated to 1 GBq after 3 min. The number is sufficient for the practical application in medical imaging for PET.

  13. Specifications of nanosecond laser ablation with solid targets, aluminum, silicon rubber, and polymethylmethacrylate (PMMA)

    Science.gov (United States)

    Morshedian, Nader

    2017-09-01

    The ablation parameters such as threshold fluence, etch depth, ablation rate and the effect of material targets were investigated under the interaction of laser pulse with low intensity. The parameters of the laser system are: laser pulse energy in the range of 110-140 mJ, wavelength 1064 nm and pulse duration 20 ns. By macroscopic estimation of the outward images of the ablation and data obtained, we can conclude that the photothermal and photoionization processes have more influence for aluminum ablation. In contrast, for polymer samples, from the macroscopic observation of the border pattern at the irradiated spot, and also the data obtained from the experiment results, we deduce that both chemical change due to heating and photochemical dissociation were effective mechanisms of ablation. However, concerning the two polymer samples, apart from considering the same theoretical ablation model, it is conceived that the photomehanical specifications of PMMA are involved in the ablation parameters. The threshold fluence for an ablation rate of 30 laser shots were obtained as 12.4, 24.64, and 11.71 J cm-2, for aluminum, silicon rubber and polymethylmethacrylate (PMMA) respectively. The ablation rate is exponentially decreased by the laser-shot number, especially for aluminum. Furthermore, the etch depth after 30 laser shots was measured as 180, 630 and 870 μm, for aluminum, silicon rubber and PMMA, respectively.

  14. Active frequency stabilization of a 1.062-micron, Nd:GGG, diode-laser-pumped nonplanar ring oscillator to less than 3 Hz of relative linewidth

    Science.gov (United States)

    Day, T.; Gustafson, E. K.; Byer, R. L.

    1990-01-01

    Results are presented on the frequency stabilization of two diode-laser-pumped ring lasers that are independently locked to the same high-finesse interferometer. The relative frequency stability is measured by locking the lasers one free spectral range apart and observing the heterodyne beat note. The resultant beat note width of 2.9 Hz is consistent with the theoretical system noise-limited linewidth and is approximately 20 times that expected for shot-noise-limited performance.

  15. Theory of some laser noise effects.

    Science.gov (United States)

    Wang, Y. K.; Lamb, W. E., Jr.

    1973-01-01

    A simple version of the semiclassical theory is applied to the shot effect. Considerations of thermal noise reported by Lamb (1965) are extended to take into account amplitude fluctuations. The laser is considered to be a lossy cavity of the Fabry-Perot type in single-mode operation with a circular frequency driven by an inverted population of active atoms. The electric field is taken to be transverse to the cavity axis. The amplitude and phase are assumed to be slowly varying functions which satisfy two self-consistency equations.

  16. Laser propulsion activity in South Africa

    CSIR Research Space (South Africa)

    Michaelis, MM

    2006-07-01

    Full Text Available projectiles reportedly ‘hit the roof’ some 10 metres high. Unfortunately, no momentum coupling constants were available, nor was there any time to take measurements. As to HF laser propulsion, only a rudimentary single-shot pendulum test was performed... together with a propulsion demonstration with a small plastic target. The reason for report- ing this is that HF LP or DF (deuterium fluoride) LP was the first type envisaged2 but has never been developed even in the laboratory. The South African HF...

  17. Laser-driven soft-X-ray undulator source

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Matthias

    2010-08-04

    The experimental results described in this thesis demonstrate the successful synergy between the research fields described above: the development of an undulator source driven by laser-plasma accelerated electron beams. First efforts in this new field have led to the production of radiation in the visible to infrared part of the electromagnetic spectrum [Schlenvoigt et al., 2008]. In contrast to these early achievements, the experiment described here shows the successful production of laser-driven undulator radiation in the soft-X-ray range with a remarkable reproducibility. The source produced tunable, collimated beams with a wavelength of {proportional_to}17 nm from a compact setup. Undulator spectra were detected in {proportional_to}70% of consecutive driver-laser shots, which is a remarkable reproducibility for a first proof-of-concept demonstration using ultra-high intensity laser systems. This can be attributed to a stable electron acceleration scheme as well as to the first application of miniature magnetic quadrupole lenses with laseraccelerated beams. The lenses significantly reduce the electron beam divergence and its angular shot-to-shot fluctuations The setup of this experiment is the foundation of potential university-laboratory-sized, highly-brilliant hard X-ray sources. By increasing the electron energy to about 1 GeV, X-ray pulses with an expected duration of {proportional_to}10 fs and a photon energy of 1 keV could be produced in an almost identical arrangement. It can also be used as a testbed for the development of a free-electron laser of significantly smaller dimension than facilities based on conventional accelerators [Gruener et al., 2007]. Such compact sources have the potential for application in many fields of science. In addition, these developments could lead to ideal sources for ultrafast pump-probe experiments due to the perfect synchronization of the X-ray beam to the driver laser. (orig.)

  18. Laser-driven soft-X-ray undulator source

    International Nuclear Information System (INIS)

    Fuchs, Matthias

    2010-01-01

    The experimental results described in this thesis demonstrate the successful synergy between the research fields described above: the development of an undulator source driven by laser-plasma accelerated electron beams. First efforts in this new field have led to the production of radiation in the visible to infrared part of the electromagnetic spectrum [Schlenvoigt et al., 2008]. In contrast to these early achievements, the experiment described here shows the successful production of laser-driven undulator radiation in the soft-X-ray range with a remarkable reproducibility. The source produced tunable, collimated beams with a wavelength of ∝17 nm from a compact setup. Undulator spectra were detected in ∝70% of consecutive driver-laser shots, which is a remarkable reproducibility for a first proof-of-concept demonstration using ultra-high intensity laser systems. This can be attributed to a stable electron acceleration scheme as well as to the first application of miniature magnetic quadrupole lenses with laseraccelerated beams. The lenses significantly reduce the electron beam divergence and its angular shot-to-shot fluctuations The setup of this experiment is the foundation of potential university-laboratory-sized, highly-brilliant hard X-ray sources. By increasing the electron energy to about 1 GeV, X-ray pulses with an expected duration of ∝10 fs and a photon energy of 1 keV could be produced in an almost identical arrangement. It can also be used as a testbed for the development of a free-electron laser of significantly smaller dimension than facilities based on conventional accelerators [Gruener et al., 2007]. Such compact sources have the potential for application in many fields of science. In addition, these developments could lead to ideal sources for ultrafast pump-probe experiments due to the perfect synchronization of the X-ray beam to the driver laser. (orig.)

  19. Effects of actions preceding the jump shot on gaze behavior and shooting performance in elite female basketball players

    NARCIS (Netherlands)

    Oudejans, R.R.D.; Karamat, R.S.; Stolk, M.H.

    2012-01-01

    The aim was to investigate the effects of different actions preceding the jump shot on basketball shooting in expert female basketball players. Participants took two-point jump shots after a dribble or after receiving a pass. The dribble was executed with the dominant or non-dominant hand.

  20. Shot-peening effect on the structure, microhardness, and compressive stresses of the austenitic steel 1.4539

    Directory of Open Access Journals (Sweden)

    Barbara Nasiłowska

    2015-06-01

    Full Text Available This article presents shot-peening effect on the structure, microhardness, and compressive stresses of the austenitic steel 1.4539. The research shows strengthening of the top layer and the formation of compressive stresses in the subsurface layers of the shot-peening elements.[b]Keyword[/b]: austenitic steel 1.4539, residual stresses, Waisman-Phillips’a method

  1. Shot noise as a probe of spin-polarized transport through single atoms

    DEFF Research Database (Denmark)

    Burtzlaff, Andreas; Weismann, Alexander; Brandbyge, Mads

    2015-01-01

    Single atoms on Au(111) surfaces have been contacted with the Au tip of a low temperature scanning tunneling microscope. The shot noise of the current through these contacts has been measured up to frequencies of 120 kHz and Fano factors have been determined to characterize the transport channels...

  2. Eating Disorders Prevention Programming May Be Failing: Evaluation of 2 One-Shot Programs.

    Science.gov (United States)

    Martz, Denise M.; Bazzini, Doris G.

    1999-01-01

    Two studies (N=114; n=77) were conducted to evaluate the impact of one-shot interventions to prevent eating disorders. Results of the first study were positive but small. The second study showed minimal effects on dieting and body esteem at one-month follow-up. The overall utility of such programming is discussed. (Author/EMK)

  3. Two-step estimation procedures for inhomogeneous shot-noise Cox processes

    DEFF Research Database (Denmark)

    Prokesová, Michaela; Dvorák, Jirí; Jensen, Eva B. Vedel

    In the present paper we develop several two-step estimation procedures for inhomogeneous shot-noise Cox processes. The intensity function is parametrized by the inhomogeneity parameters while the pair-correlation function is parametrized by the interaction parameters. The suggested procedures...

  4. A solid target for SINQ based on a Pb-shot Pebble-bed

    International Nuclear Information System (INIS)

    Atchison, F.; Heidenreich, G.

    1991-01-01

    Preliminary results from scoping calculations examining the possibilities of implementing a Pebble-bed of Pb-shot as a target for SINQ are presented. The primary design objects are set out and estimates of heating and activation given. Cooling circuit parameters are discussed and estimates for operating conditions presented. A short discussion of problems associated with a realisation is included. (author)

  5. Watching More Closely: Shot Scale Affects Film Viewers' Theory of Mind Tendency But Not Ability.

    Science.gov (United States)

    Rooney, Brendan; Bálint, Katalin E

    2017-01-01

    Recent research debates the effects of exposure to narrative fiction on recognition of mental states in others and self, referred to as Theory of Mind. The current study explores the mechanisms by which such effects could occur in fictional film. Using manipulated film scenes, we conducted a between subject experiment ( N = 136) exploring how film shot-scale affects viewers' Theory of Mind. Specifically, in our methods we distinguish between the trait Theory of Mind abilities (ToM ability), and the state-like tendency to recognize mental states in others and self (ToM tendency). Results showed that close-up shots (compared to long shots) of a character was associated with higher levels of Theory of Mind tendency, when the facial expression was sad but not when it was neutral. And this effect did not transfer to other characters in the film. There was also no observable effect of character depiction on viewers' general Theory of Mind ability. Together the findings suggest that formal and content features of shot scale can elicit Theory of Mind responses by directing attention toward character mental states rather than improving viewers' general Theory of Mind ability.

  6. IMPROVED MOTOR-TIMING: EFFECTS OF SYNCHRONIZED METRO-NOME TRAINING ON GOLF SHOT ACCURACY

    Directory of Open Access Journals (Sweden)

    Louise Rönnqvist

    2009-12-01

    Full Text Available This study investigates the effect of synchronized metronome training (SMT on motor timing and how this training might affect golf shot accuracy. Twenty-six experienced male golfers participated (mean age 27 years; mean golf handicap 12.6 in this study. Pre- and post-test investigations of golf shots made by three different clubs were conducted by use of a golf simulator. The golfers were randomized into two groups: a SMT group and a Control group. After the pre-test, the golfers in the SMT group completed a 4-week SMT program designed to improve their motor timing, the golfers in the Control group were merely training their golf-swings during the same time period. No differences between the two groups were found from the pre-test outcomes, either for motor timing scores or for golf shot accuracy. However, the post-test results after the 4-weeks SMT showed evident motor timing improvements. Additionally, significant improvements for golf shot accuracy were found for the SMT group and with less variability in their performance. No such improvements were found for the golfers in the Control group. As with previous studies that used a SMT program, this study's results provide further evidence that motor timing can be improved by SMT and that such timing improvement also improves golf accuracy

  7. Light emission probing quantum shot noise and charge fluctuations at a biased molecular junction

    DEFF Research Database (Denmark)

    Schneider, N.L.; Lu, Jing Tao; Brandbyge, M.

    2012-01-01

    The emission of plasmonic light from a single C60 molecule on Cu(111) is probed in a scanning tunneling microscope from the weak-coupling, tunneling range to strong coupling of the molecule to the electrodes at contact. At positive sample voltage the photon yield decreases owing to shot...

  8. Effect of Shot Peening on the Fatigue Strength of Automotive Tubular Stabilizer Bars DC 218

    Directory of Open Access Journals (Sweden)

    Wittek A.M.

    2016-12-01

    Full Text Available This paper concerns issues related to the development of designs of stabilizer bars for new motor vehicle models. It involves not only the designing of a stabilizer bar with the shape required by the manufacturer, but also the preparation of bending and heat treatment processes as well as the performance of strength and fatigue tests. In the prototype development phase, the simulations techniques (FEM may be used to assess the design. The article contains a detailed analysis of a stabilizer bar designated with the DC 218 VA symbol. Performed numerical strength and fatigue calculations showed that the developed stabilizer bar design with the desired shape did not achieve the required number of fatigue cycles. It was also proven at the test stand by testing a prototype stabilizer bar. Therefore, it was suggested to supplement the technological process with an additional shot peening operation whose main aim was to reduce the length of microcracks on the stabilizer bar’s surface. This effect was confirmed during comparative metallographic tests of not shot – peened and shot – peened stabilizer bars. After shot peening, the analysed stabilizer bar reached a fatigue strength which exceeded the limits set by the manufacturer.

  9. Residual stress redistribution in shot peened samples subject to mechanical loading

    International Nuclear Information System (INIS)

    Buchanan, Dennis J.; John, Reji

    2014-01-01

    Shot peening is a well-established surface treatment process that imparts large compressive residual stresses onto the surface and at shallow depths to retard initiation and growth of fatigue cracks. The plastic deformation developed during the surface treatment sets up a constraint that retains compressive stresses on the surface balanced by tensile residual stresses in the interior. However, component service histories that produce subsequent plastic deformation may redistribute these residual stresses. In most engineering components, this additional plastic deformation is localized to stress concentration sites such as holes, notches, and fillets. In the case of gross plastic deformation where the entire cross section experiences material yielding the residual stress profile may redistribute, resulting in tensile stresses on the outside surface balanced by compression in the interior. This paper describes a series of experiments combined with models to explain the redistribution in residual stress depth profiles subject to applied stresses producing gross plastic strains in shot peened laboratory specimens. The initial room temperature residual stress and plastic strain profiles provide initial conditions for predictions. Model predictions correlate well with experimental results on shot peened dogbone specimens subject to single cycle and fatigue loading conditions at elevated temperature. Experiments on shot peened notched specimens do not exhibit the same stress redistribution even for larger applied stresses

  10. Serious Hazards of Transfusion (SHOT) haemovigilance and progress is improving transfusion safety.

    Science.gov (United States)

    Bolton-Maggs, Paula H B; Cohen, Hannah

    2013-11-01

    The Serious Hazards of Transfusion (SHOT) UK confidential haemovigilance reporting scheme began in 1996. Over the 16 years of reporting, the evidence gathered has prompted changes in transfusion practice from the selection and management of donors to changes in hospital practice, particularly better education and training. However, half or more reports relate to errors in the transfusion process despite the introduction of several measures to improve practice. Transfusion in the UK is very safe: 2·9 million components were issued in 2012, and very few deaths are related to transfusion. The risk of death from transfusion as estimated from SHOT data in 2012 is 1 in 322,580 components issued and for major morbidity, 1 in 21,413 components issued; the risk of transfusion-transmitted infection is much lower. Acute transfusion reactions and transfusion-associated circulatory overload carry the highest risk for morbidity and death. The high rate of participation in SHOT by National Health Service organizations, 99·5%, is encouraging. Despite the very useful information gained about transfusion reactions, the main risks remain human factors. The recommendations on reduction of errors through a 'back to basics' approach from the first annual SHOT report remain absolutely relevant today. © 2013 The Authors. British Journal of Haematology published by John Wiley & Sons Ltd.

  11. Visual one-shot learning as an 'anti-camouflage device': a novel morphing paradigm.

    Science.gov (United States)

    Ishikawa, Tetsuo; Mogi, Ken

    2011-09-01

    Once people perceive what is in the hidden figure such as Dallenbach's cow and Dalmatian, they seldom seem to come back to the previous state when they were ignorant of the answer. This special type of learning process can be accomplished in a short time, with the effect of learning lasting for a long time (visual one-shot learning). Although it is an intriguing cognitive phenomenon, the lack of the control of difficulty of stimuli presented has been a problem in research. Here we propose a novel paradigm to create new hidden figures systematically by using a morphing technique. Through gradual changes from a blurred and binarized two-tone image to a blurred grayscale image of the original photograph including objects in a natural scene, spontaneous one-shot learning can occur at a certain stage of morphing when a sufficient amount of information is restored to the degraded image. A negative correlation between confidence levels and reaction times is observed, giving support to the fluency theory of one-shot learning. The correlation between confidence ratings and correct recognition rates indicates that participants had an accurate introspective ability (metacognition). The learning effect could be tested later by verifying whether or not the target object was recognized quicker in the second exposure. The present method opens a way for a systematic production of "good" hidden figures, which can be used to demystify the nature of visual one-shot learning.

  12. Single-shot two-dimensional full-range optical coherence tomography achieved by dispersion control

    NARCIS (Netherlands)

    Witte, S.; Baclayon, M.; Peterman, E.J.G.; Toonen, R.F.G.; Mansvelder, H.D.; Groot, M.L.

    2009-01-01

    We present a full-range Fourier-domain optical coherence tomography (OCT) system that is capable of acquiring two-dimensional images of living tissue in a single shot. By using line illumination of the sample in combination with a two-dimensional imaging spectrometer, 1040 depth scans are performed

  13. Watching More Closely: Shot Scale Affects Film Viewers’ Theory of Mind Tendency But Not Ability

    Science.gov (United States)

    Rooney, Brendan; Bálint, Katalin E.

    2018-01-01

    Recent research debates the effects of exposure to narrative fiction on recognition of mental states in others and self, referred to as Theory of Mind. The current study explores the mechanisms by which such effects could occur in fictional film. Using manipulated film scenes, we conducted a between subject experiment (N = 136) exploring how film shot-scale affects viewers’ Theory of Mind. Specifically, in our methods we distinguish between the trait Theory of Mind abilities (ToM ability), and the state-like tendency to recognize mental states in others and self (ToM tendency). Results showed that close-up shots (compared to long shots) of a character was associated with higher levels of Theory of Mind tendency, when the facial expression was sad but not when it was neutral. And this effect did not transfer to other characters in the film. There was also no observable effect of character depiction on viewers’ general Theory of Mind ability. Together the findings suggest that formal and content features of shot scale can elicit Theory of Mind responses by directing attention toward character mental states rather than improving viewers’ general Theory of Mind ability. PMID:29387032

  14. A practical globalization of one-shot optimization for optimal design of tokamak divertors

    Energy Technology Data Exchange (ETDEWEB)

    Blommaert, Maarten, E-mail: maarten.blommaert@kuleuven.be [Institute of Energy and Climate Research (IEK-4), FZ Jülich GmbH, D-52425 Jülich (Germany); Dekeyser, Wouter; Baelmans, Martine [KU Leuven, Department of Mechanical Engineering, 3001 Leuven (Belgium); Gauger, Nicolas R. [TU Kaiserslautern, Chair for Scientific Computing, 67663 Kaiserslautern (Germany); Reiter, Detlev [Institute of Energy and Climate Research (IEK-4), FZ Jülich GmbH, D-52425 Jülich (Germany)

    2017-01-01

    In past studies, nested optimization methods were successfully applied to design of the magnetic divertor configuration in nuclear fusion reactors. In this paper, so-called one-shot optimization methods are pursued. Due to convergence issues, a globalization strategy for the one-shot solver is sought. Whereas Griewank introduced a globalization strategy using a doubly augmented Lagrangian function that includes primal and adjoint residuals, its practical usability is limited by the necessity of second order derivatives and expensive line search iterations. In this paper, a practical alternative is offered that avoids these drawbacks by using a regular augmented Lagrangian merit function that penalizes only state residuals. Additionally, robust rank-two Hessian estimation is achieved by adaptation of Powell's damped BFGS update rule. The application of the novel one-shot approach to magnetic divertor design is considered in detail. For this purpose, the approach is adapted to be complementary with practical in parts adjoint sensitivities. Using the globalization strategy, stable convergence of the one-shot approach is achieved.

  15. Regularity of particle velocity decrease with scale d distance for rockbursts and shot holes

    Czech Academy of Sciences Publication Activity Database

    Holub, Karel; Rušajová, Jana

    2015-01-01

    Roč. 20, č. 2 (2015), s. 80-85 ISSN 1335-1788 Institutional support: RVO:68145535 Keywords : rockburst * hole shot * particle velocity * scaled distance * cylindrical and spherical waveforms Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.390, year: 2015 http://actamont.tuke.sk/pdf/2015/n2/2holub.pdf

  16. Analysis of shots on target and goals scored in soccer matches ...

    African Journals Online (AJOL)

    The aim of this study was to analyse the characteristics and patterns of shots on target and goals scored during the 2012-European Championship. The broadcasted matches were recorded and converted into electronic video files for a computerbased analysis. This quantitative study examined 31 matches of the ...

  17. Watching More Closely: Shot Scale Affects Film Viewers’ Theory of Mind Tendency But Not Ability

    Directory of Open Access Journals (Sweden)

    Brendan Rooney

    2018-01-01

    Full Text Available Recent research debates the effects of exposure to narrative fiction on recognition of mental states in others and self, referred to as Theory of Mind. The current study explores the mechanisms by which such effects could occur in fictional film. Using manipulated film scenes, we conducted a between subject experiment (N = 136 exploring how film shot-scale affects viewers’ Theory of Mind. Specifically, in our methods we distinguish between the trait Theory of Mind abilities (ToM ability, and the state-like tendency to recognize mental states in others and self (ToM tendency. Results showed that close-up shots (compared to long shots of a character was associated with higher levels of Theory of Mind tendency, when the facial expression was sad but not when it was neutral. And this effect did not transfer to other characters in the film. There was also no observable effect of character depiction on viewers’ general Theory of Mind ability. Together the findings suggest that formal and content features of shot scale can elicit Theory of Mind responses by directing attention toward character mental states rather than improving viewers’ general Theory of Mind ability.

  18. Comparative Study on the Efficacy of Two Regimens of Single-Shot ...

    African Journals Online (AJOL)

    ... mother by increasing self esteem and improving bonding with the baby. Objective: To assess and compare the satisfaction and efficacy of two regimens of single-shot spinal blocks for the relief of labor pain in women who present in active phase of labour. Design: A prospective randomised single-blind observational study

  19. A second-order autocorrelator for single-shot measurement of ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    mental and second-harmonic frequency respectively, and 2α is the crossover angle of the beams inside the ... dispersion (GVD) effects in the crystal and spatial resolution of the imaging system. In the case ... Figure 3a shows the image of SH radiation from the KDP crystal corresponding to the single- shot operation of the ...

  20. Prebiotic effect of fruit and vegetable shots containing Jerusalem artichoke inulin: a human intervention study.

    Science.gov (United States)

    Ramnani, P; Gaudier, E; Bingham, M; van Bruggen, P; Tuohy, K M; Gibson, G R

    2010-07-01

    The present study aimed to determine the prebiotic effect of fruit and vegetable shots containing inulin derived from Jerusalem artichoke (JA). A three-arm parallel, placebo-controlled, double-blind study was carried out with sixty-six healthy human volunteers (thirty-three men and thirty-three women, age range: 18-50 years). Subjects were randomised into three groups (n 22) assigned to consume either the test shots, pear-carrot-sea buckthorn (PCS) or plum-pear-beetroot (PPB), containing JA inulin (5 g/d) or the placebo. Fluorescent in situ hybridisation was used to monitor populations of total bacteria, bacteroides, bifidobacteria, Clostridium perfringens/histolyticum subgroup, Eubacterium rectale/Clostridium coccoides group, Lactobacillus/Enterococcus spp., Atopobium spp., Faecalibacterium prausnitzii and propionibacteria. Bifidobacteria levels were significantly higher on consumption of both the PCS and PPB shots (10.0 (sd 0.24) and 9.8 (sd 0.22) log10 cells/g faeces, respectively) compared with placebo (9.3 (sd 0.42) log10 cells/g faeces) (P 90 %) to the product was observed. The present study confirms the prebiotic efficacy of fruit and vegetable shots containing JA inulin.

  1. Feature Selection Methods for Zero-Shot Learning of Neural Activity

    Directory of Open Access Journals (Sweden)

    Carlos A. Caceres

    2017-06-01

    Full Text Available Dimensionality poses a serious challenge when making predictions from human neuroimaging data. Across imaging modalities, large pools of potential neural features (e.g., responses from particular voxels, electrodes, and temporal windows have to be related to typically limited sets of stimuli and samples. In recent years, zero-shot prediction models have been introduced for mapping between neural signals and semantic attributes, which allows for classification of stimulus classes not explicitly included in the training set. While choices about feature selection can have a substantial impact when closed-set accuracy, open-set robustness, and runtime are competing design objectives, no systematic study of feature selection for these models has been reported. Instead, a relatively straightforward feature stability approach has been adopted and successfully applied across models and imaging modalities. To characterize the tradeoffs in feature selection for zero-shot learning, we compared correlation-based stability to several other feature selection techniques on comparable data sets from two distinct imaging modalities: functional Magnetic Resonance Imaging and Electrocorticography. While most of the feature selection methods resulted in similar zero-shot prediction accuracies and spatial/spectral patterns of selected features, there was one exception; A novel feature/attribute correlation approach was able to achieve those accuracies with far fewer features, suggesting the potential for simpler prediction models that yield high zero-shot classification accuracy.

  2. A novel percutaneous nephrolithotomy (PCNL set: The ‘Economical One-shot PCNL Set’ (Ecoset

    Directory of Open Access Journals (Sweden)

    Necmettin Penbegul

    2017-09-01

    Conclusions: The one-shot dilatation technique using the Ecoset for PCNL can be feasibly, safely, and effectively performed in almost every adult patient. The Amplatz dilator set and balloon dilator set have the disadvantage of relatively high cost, whereas the Ecoset is the cheapest ‘disposable set’ that can be used during PCNL surgery.

  3. Single-shot LIBS spectral quality for waste particles in open air

    NARCIS (Netherlands)

    Xia, H.; Bakker, M.C.M.

    2015-01-01

    This work investigates the ability of LIBS to produce quality spectra from small particles of concrete demolition waste using single-shot spectra collected in open air. The 2–8?mm materials are rounded river gravel, green glass shards, and plastic flakes. Considered are focal length, air, moisture,

  4. Zero-Shot Learning - The Good, the Bad and the Ugly

    NARCIS (Netherlands)

    Xian, Y.; Schiele, B.; Akata, Z.

    2017-01-01

    Due to the importance of zero-shot learning, the number of proposed approaches has increased steadily recently. We argue that it is time to take a step back and to analyze the status quo of the area. The purpose of this paper is three-fold. First, given the fact that there is no agreed upon

  5. Shot Noise and Fiber Amplifier Effects in Photonic-Doppler Velocimetry Systems

    Science.gov (United States)

    Miller, Edward Kirk; Larson, Eric; Lee, Kevin

    2017-06-01

    We present theoretical and experimental data to show the effects of shot noise and erbium-doped fiber amplifiers (EDFA's) on the achievable dynamic range of photonic-Doppler velocimetry (PDV) systems. We show that many common system configurations are very nearly shot noise limited. Heterodyne gain from strong local-oscillator (LO) light creates a signal amplitude that can be recorded on high-speed digitizers, and the shot noise from the LO sets the system noise floor above the levels of electronic noise in the photoreceiver and digitizer. We show that boosting weak signal returns using an EDFA creates noise in the same proportion that it increases signal, leaving the signal-to-noise ratio (SNR) unchanged. Amplified spontaneous emission (ASE) from the EDFA, when mixed with the LO light, creates a noise term proportional to the LO shot noise and to the EDFA gain. The net result is that EDFA's are useful for boosting heterodyne signal levels for recording, and they can be used to boost weak return light before lossy components, but they do not improve the fundamental SNR of the system.

  6. A study on the corrosion characteristics of gear steel by shot peening

    International Nuclear Information System (INIS)

    Kang, Jin Shik; Kim, Tae Hyung; Cheong, Seong Kyun; Yoon, Jong Ku; Lee, Seung Ho

    2001-01-01

    The surface treatment technique to increase corrosion resistance is very important in mechanical components of structures. Therefore, this paper investigates the effects of shot peening on the corrosion resistance of SCM 420steel. The results show that the surface compressive residual stress largely increases, which cause the increase of corrosion resistance

  7. 77 FR 58114 - SunShot Prize: Race to the Rooftop

    Science.gov (United States)

    2012-09-19

    ...: Race to the Rooftop competition challenges the ingenuity of America's businesses and communities to... achieve a $1 per watt non-hardware cost using innovative, verifiable processes and business practices. As... competition. Today's notice announces the SunShot Prize and the release of prize rules. Issued in Washington...

  8. Micron-scale resolution radiography of laser-accelerated and laser-exploded foils using an yttrium x-ray laser

    International Nuclear Information System (INIS)

    Cauble, R.; Da Silva, L.B.; Barbee, T.W. Jr.; Celliers, P.; Moreno, J.C.; Mrowka, S.; Perry, T.S.; Wan, A.S.

    1994-09-01

    The authors have imaged laser-accelerated foils and exploding foils on the few-micron scale using an yttrium x-ray laser (155 angstrom, 80 eV, ∼200 ps duration) and a multilayer mirror imaging system. At the maximum magnification of 30, resolution was of order one micron. The images were side-on radiographs of the foils. Accelerated foils showed significant filamentation on the rear-side (away from the driving laser) of the foil, although the laser beam was smoothed. In addition to the narrow rear-side filamentation, some shots revealed larger-scale plume-like structures on the front (driven) side of the Al foil. These plumes seem to be little-affected by beam smoothing and are likely a consequence of Rayleigh-Taylor instability. The experiments were carried out at the Nova two-beam facility

  9. Time resolved temperature measurement of polymer surface irradiated by mid-IR free electron laser

    Science.gov (United States)

    Araki, Mitsunori; Chiba, Tomoyuki; Oyama, Takahiro; Imai, Takayuki; Tsukiyama, Koichi

    2017-08-01

    We have developed the time-resolved temperature measurement system by using a radiation thermometer FLIR SC620. Temporal temperature profiles of an acrylic resin surface by the irradiation of infrared free electron laser (FEL) pulse were recorded in an 8 ms resolution to measure an instantaneous temperature rise and decay profile. Under the single-shot condition, a peak temperature defined as the temperature jump from the ambient temperature was found to be proportional to the absorbance. Under the multi-shot condition, the temperature accumulation was found to reach a roughly constant value where the supply and release of the heat is balanced.

  10. MR cholangiopancreatography of pancreaticobiliary diseases: Comparison of single-shot RARE and multislice HASTE sequences

    Energy Technology Data Exchange (ETDEWEB)

    Morrin, Martina M.; Farrell, Richard J.; McEntee, Gerry; MacMathuna, Padraic; Stack, John P.; Murrah, John G

    2000-11-01

    AIMS: We prospectively compared two breath-hold magnetic resonance cholangiopancreatography (MRCP) sequences: single-shot rapid acquisition with relaxation enhancement (RARE) and multislice half-Fourier acquisition single-shot turbo spin echo (HASTE) in imaging the pancreaticobiliary system. PATIENTS AND METHODS: The diagnostic accuracy of single-shot RARE and multislice HASTE was studied in 34 subjects who had undergone conventional cholangiopancreatography. Overall image quality, duct conspicuity, image artifact, signal intensity and contrast-to-noise ratios were assessed independently by two radiologists who were unaware of the underlying diagnosis. RESULTS: Both sequences had comparable diagnostic accuracy regarding a normal biliary system, choledocholithiasis, extra-hepatic and intra-hepatic strictures. Single-shot RARE was superior to multislice HASTE in diagnosing a normal pancreatic system, pancreatic and intrahepatic duct strictures, while providing significantly better image quality (mean {+-} SE 3.7 {+-} 0.07 vs 3.3 {+-} 0.08: P = 0.02) and significantly less image artifact (mean {+-} SE 3.6 {+-} 0.07 vs 3.2 {+-} 0.08:P = 0.01). Single-shot RARE provided significantly better duct conspicuity regarding the pancreatic duct within the body (2.7 {+-} 0.2 vs 2.1 {+-} 0.2: P = 0.003) and tail (2.4 {+-} 0.2 vs 1.6 {+-} 0.2;P = 0.0001), as well as the intrahepatic ducts (3.0 {+-} 0.1 vs 2.6 {+-} 0.1: P = 0.004) but there was no significant difference regarding the remainder of the biliary tree. CONCLUSION: Single-shot RARE provides superior image quality, duct conspicuity with the added advantage of less image artifact and shorter acquisition time. However, volume averaging can cause common bile duct stones to be missed. Therefore, multislice HASTE sequences should still be acquired if choledocholithiasis is suspected. Larger studies are required to assess the diagnostic efficacy of single-shot RARE sequences in pancreatic duct and intra-hepatic duct disease

  11. The jump shot - a biomechanical analysis focused on lateral ankle ligaments.

    Science.gov (United States)

    Lindner, M; Kotschwar, A; Zsoldos, R R; Groesel, M; Peham, C

    2012-01-03

    Handball is one of the top four athletic games with highest injury risks. The jump shot is the most accomplished goal shot technique and the lower extremities are mostly injured. As a basis for ankle sprain simulation, the aim of this study was to extend the ankle region of an existing musculoskeletal full-body model through incorporation of three prominent lateral ankle ligaments: ligamentum fibulotalare anterius (LFTA), ligamentum fibulotalare posterius (LFTP), ligamentum fibulocalcaneare (LFC). The specific objective was to calculate and visualise ligament force scenarios during the jumping and landing phases of controlled jump shots. Recorded kinematic data of performed jump shots and the corresponding ground reaction forces were used to perform inverse dynamics. The calculated peak force of the LFTA (107 N) was found at maximum plantarflexion and of the LFTP (150 N) at maximum dorsiflexion. The peak force of the LFC (190 N) was observed at maximum dorsiflexion combined with maximum eversion. Within the performed jump shots, the LFTA showed a peak force (59 N to 69 N) during maximum plantarflexion in the final moment of the lift off. During landing, the force developed by the LFTA reached its peak value (61 N to 70 N) at the first contact with the floor. After that, the LFTP developed a peak force (70 N to 118 N). This model allows the calculation of forces in lateral ankle ligaments. The information obtained in this study can serve as a basis for future research on ankle sprain and ankle sprain simulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Retrograde hot-shot cardioplegia in patients with left ventricular hypertrophy undergoing aortic valve replacement.

    Science.gov (United States)

    Ascione, Raimondo; Suleiman, Saadeh M; Angelini, Gianni D

    2008-02-01

    Intermittent antegrade cold-blood cardioplegia followed by terminal warm-blood cardioplegic reperfusion or hot-shot is reported to reduce myocardial injury in the setting of coronary surgery. The efficacy of this cardioplegic technique in patients with left ventricular hypertrophy secondary to aortic stenosis remains uncertain. Thirty-six patients with left ventricular hypertrophy undergoing aortic valve replacement were prospectively randomized to cold-blood cardioplegia either alone (cold-blood cardioplegia group) or with retrograde hot-shot (hot-shot group). Reperfusion injury was assessed by measuring myocardial levels of adenosine triphosphate and lactate in left and right ventricular biopsies taken 5 minutes after institution of cardiopulmonary bypass and 20 minutes after removal of cross-clamp using high-performance liquid chromatography and enzymatic techniques. Myocardial injury was assessed by serial release of troponin I up to 48 hours postoperatively. Overall clinical outcome was prospectively collected. Baseline and intraoperative characteristics were similar between groups. In the hot-shot group, there were no significant changes in the myocardial concentration of adenosine triphosphate and lactate in both left and right ventricular biopsies after reperfusion. In the cold-blood cardioplegia group, there was a trend to a fall in adenosine triphosphate levels in the left and right ventricular biopsies after reperfusion, but this reached statistical significance only in the right ventricle. Troponin I release was raised in both groups at 4 and 12 hours after surgery (p < 0.05), but did not reach levels of myocardial infarction. The terminal retrograde hot-shot reperfusion does not add any extra benefit to antegrade cold-blood cardioplegia in preventing myocardial injury in patients with left ventricular hypertrophy undergoing aortic valve replacement. Nevertheless, it appears to reduce ischemic stress in the right ventricle. There was no difference in

  13. Is Attribute-Based Zero-Shot Learning an Ill-Posed Strategy?

    KAUST Repository

    Alabdulmohsin, Ibrahim

    2016-09-03

    One transfer learning approach that has gained a wide popularity lately is attribute-based zero-shot learning. Its goal is to learn novel classes that were never seen during the training stage. The classical route towards realizing this goal is to incorporate a prior knowledge, in the form of a semantic embedding of classes, and to learn to predict classes indirectly via their semantic attributes. Despite the amount of research devoted to this subject lately, no known algorithm has yet reported a predictive accuracy that could exceed the accuracy of supervised learning with very few training examples. For instance, the direct attribute prediction (DAP) algorithm, which forms a standard baseline for the task, is known to be as accurate as supervised learning when as few as two examples from each hidden class are used for training on some popular benchmark datasets! In this paper, we argue that this lack of significant results in the literature is not a coincidence; attribute-based zero-shot learning is fundamentally an ill-posed strategy. The key insight is the observation that the mechanical task of predicting an attribute is, in fact, quite different from the epistemological task of learning the “correct meaning” of the attribute itself. This renders attribute-based zero-shot learning fundamentally ill-posed. In more precise mathematical terms, attribute-based zero-shot learning is equivalent to the mirage goal of learning with respect to one distribution of instances, with the hope of being able to predict with respect to any arbitrary distribution. We demonstrate this overlooked fact on some synthetic and real datasets. The data and software related to this paper are available at https://mine. kaust.edu.sa/Pages/zero-shot-learning.aspx. © Springer International Publishing AG 2016.

  14. Laser Damage Inspection Final Report

    International Nuclear Information System (INIS)

    Salmon, J.T.; Brase, J.M.; Bliss, E.S.; Carrano, C.J.; Kegelmeyer, L.M.; Miller, M.G.; Orth, C.D.; Sacks, R.A.

    2001-01-01

    Large, high-power laser systems are often designed as reimaging multipass cavities to maximize the extraction of energy from the amplifiers. These multipass cavities often have vacuum spatial filters that suppress the growth of beam instability via B-integral effects. These spatial filters also relay images of laser damage, often nearly superimposing these images in common planes. Also, the fluence damage threshold limits the minimum size of the optics. When used as vacuum barriers in the spatial filters, these large optics present a safety hazard from the risk of implosion if the laser damage were sufficiently large. The objective of the project was to develop algorithms and methods for optical detection and characterization of laser-induced damage of optics. The system should detect small defects (about 5% of the critical size), track their growth over multiple laser shots, and characterize the defects accurately so that the optic can be replaced (at 25% of the critical size) and, hence, minimize the risk of implosion. The depth of field must be short enough to isolate the damaged vacuum barrier from other damaged optics in the beamline, and the system should also be capable of inspecting other optics in the beamline, since damage on one optic can subsequently damage subsequent optics. Laser induced damage starts as a small (<<1mm) crater and grows as material is removed on subsequent laser shots. The highly fractured rough surface of the crater scatters light from the illuminating inspection beam. This scattered light is imaged by the inspection system. Other types of defects may occur as well including inclusions in the bulk glass, tooling marks, and surface contamination. This report will discuss the detection and characterization of crater-like surface defects although the general techniques may prove useful for other types of defects. The work described here covers the development of an image processing approach and specific algorithms for defect detection

  15. Laser Therapy

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Laser Resurfacing Uses for Laser Resurfacing Learn more ...

  16. The National Ignition Facility 2007 laser performance status

    Energy Technology Data Exchange (ETDEWEB)

    Haynam, C A; Sacks, R A; Wegner, P J; Bowers, M W; Dixit, S N; Erbert, G V; Heestand, G M; Henesian, M A; Hermann, M R; Jancaitis, K S; Manes, K R; Marshall, C D; Mehta, N C; Menapace, J; Nostrand, M C; Orth, C D; Shaw, M J; Sutton, S B; Williams, W H; Widmayer, C C [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94550 (United States)], E-mail: haynam1@llnl.gov (and others)

    2008-05-15

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory contains a 192-beam 3.6 MJ neodymium glass laser that is frequency converted to 351nm light. It has been designed to support high energy density science (HEDS), including the demonstration of fusion ignition through Inertial Confinement. To meet this goal, laser design criteria include the ability to generate pulses of up to 1.8-MJ total energy at 351nm, with peak power of 500 TW and precisely-controlled temporal pulse shapes spanning two orders of magnitude. The focal spot fluence distribution of these pulses is conditioned, through a combination of special optics in the 1{omega} (1053 nm) portion of the laser (continuous phase plates), smoothing by spectral dispersion (SSD), and the overlapping of multiple beams with orthogonal polarization (polarization smoothing). In 2006 and 2007, a series of measurements were performed on the NIF laser, at both 1{omega} and 3{omega} (351 nm). When scaled to full 192-beam operation, these results lend confidence to the claim that NIF will meet its laser performance design criteria and that it will be able to simultaneously deliver the temporal pulse shaping, focal spot conditioning, peak power, shot-to-shot reproducibility, and power balance requirements of indirect-drive fusion ignition campaigns. We discuss the plans and status of NIF's commissioning, and the nature and results of these measurement campaigns.

  17. Lasers technology

    International Nuclear Information System (INIS)

    2014-01-01

    The Laser Technology Program of IPEN is developed by the Center for Lasers and Applications (CLA) and is committed to the development of new lasers based on the research of new optical materials and new resonator technologies. Laser applications and research occur within several areas such as Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. Additional goals of the Program are human resource development and innovation, in association with Brazilian Universities and commercial partners

  18. [The determination of the distance of a shot from a smooth-bore weapon based on the damages from the action of the wad containers].

    Science.gov (United States)

    Korniiash, V A; Iodes, Iu V; Goloshchapov, I V

    1989-01-01

    Experimental shots from a No. 16 calibre single-barrelled gun using commercial cartridges in the plastic cartridge cases supplied by wad containers with Nos. 1 and 2 shots revealed that lesions that had typical morphologic structure which were characteristic of wad container action were produced at close distances (less than 2 meters). Therefore preliminary experimental shots are necessary before making concrete decisions on characteristic features of an injuring projectile and shot distance.

  19. Near Field Intensity Trends of Main Laser Alignment Images in the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Leach, R R; Beltsar, I; Burkhart, S; Lowe-Webb, R; Kamm, V M; Salmon, T; Wilhelmsen, K

    2015-01-22

    The National Ignition Facility (NIF) utilizes 192 high-energy laser beams focused with enough power and precision on a hydrogen-filled spherical, cryogenic target to potentially initiate a fusion reaction. NIF has been operational for six years; during that time, thousands of successful laser firings or shots have been executed. Critical instrument measurements and camera images are carefully recorded for each shot. The result is a massive and complex database or ‘big data’ archive that can be used to investigate the state of the laser system at any point in its history or to locate and track trends in the laser operation over time. In this study, the optical light throughput for more than 1600 NIF shots for each of the 192 main laser beams and 48 quads was measured over a three year period from January 2009 to October 2012. The purpose was to verify that the variation in the transmission of light through the optics over time performed within design expectations during this time period. Differences between average or integrated intensity from images recorded by the input sensor package (ISP) and by the output sensor package (OSP) in the NIF beam-line were examined. A metric is described for quantifying changes in the integrated intensity measurements and was used to view potential trends. Results are presented for the NIF input and output sensor package trends and changes over the three year time-frame.

  20. Synchronized delivery of Er:YAG-laser pulses into water studied by a laser beam transmission probe for enhanced endodontic treatment

    Science.gov (United States)

    Gregorčič, P.; Lukač, N.; Možina, J.; Jezeršek, M.

    2016-04-01

    We examine the effects of the synchronized delivery of multiple Er:YAG-laser pulses during vapor-bubble oscillations into water. For this purpose, we used a laser beam transmission probe that enables monitoring of the bubble's dynamics from a single shot. To overcome the main drawbacks of this technique, we propose and develop an appropriate and robust calibration by simultaneous employment of shadow photography. By using the developed experimental method, we show that the resonance effect is obtained when the second laser pulse is delivered at the end or slightly after the first bubble's collapse. In this case, the resonance effect increases the mechanical energy of the secondary bubble's oscillations and prolongs their duration. The presented laser method for synchronized delivery of Er:YAG-laser pulses during bubble oscillations has great potential for further improvement of laser endodontic treatment, especially upon their safety and efficiency.