WorldWideScience

Sample records for intensity laser-solid interactions

  1. Understanding laser-solid interactions at ultra-high intensities

    Science.gov (United States)

    Murphy, C. D.; Gray, R. J.; Carroll, D. C.; MacLellan, D. A.; Powell, H.; Scott, G. G.; Ridgers, C. P.; Brady, C. S.; Neely, D.; Green, J. S.; Booth, N.; McKenna, P.

    2012-10-01

    The interaction of matter with lasers is a subject which has progressed rapidly over the last two decades as higher intensity lasers have opened the door to nonlinear and then relativistic interactions such that applications in ion acceleration and x-ray backlighting sources have become a clear possibility. Until recently, lasers capable of reaching the highest intensities (˜10^21 Wcm-2) have been glass-based systems with a low shot rate making detailed studies prohibitively time consuming. The development of petawatt-class Ti:Sapphire lasers such as Astra Gemini at STFC - Rutherford Appleton Laboratory, has made the systematic studies required to understand such interaction physics feasible. One such experiment on the Astra Gemini laser will be presented. The photon and particle diagnostics used will be explained and their results presented.

  2. Relativistic Quasimonoenergetic Positron Jets from Intense Laser-Solid Interactions

    Science.gov (United States)

    Chen, Hui; Wilks, S. C.; Meyerhofer, D. D.; Bonlie, J.; Chen, C. D.; Chen, S. N.; Courtois, C.; Elberson, L.; Gregori, G.; Kruer, W.; Landoas, O.; Mithen, J.; Myatt, J.; Murphy, C. D.; Nilson, P.; Price, D.; Schneider, M.; Shepherd, R.; Stoeckl, C.; Tabak, M.; Tommasini, R.; Beiersdorfer, P.

    2010-07-01

    Detailed angle and energy resolved measurements of positrons ejected from the back of a gold target that was irradiated with an intense picosecond duration laser pulse reveal that the positrons are ejected in a collimated relativistic jet. The laser-positron energy conversion efficiency is ˜2×10-4. The jets have ˜20 degree angular divergence and the energy distributions are quasimonoenergetic with energy of 4 to 20 MeV and a beam temperature of ˜1MeV. The sheath electric field on the surface of the target is shown to determine the positron energy. The positron angular and energy distribution is controlled by varying the sheath field, through the laser conditions and target geometry.

  3. High Harmonic Radiation Generation and Attosecond pulse generation from Intense Laser-Solid Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Alexander Roy [Univ. of Michigan, Ann Arbor, MI (United States); Krushelnick, Karl [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-09-08

    We have studied ion motion effects in high harmonic generation, including shifts to the harmonics which result in degradation of the attosecond pulse train, and how to mitigate them. We have examined the scaling with intensity of harmonic emission. We have also switched the geometry of the interaction to measure, for the first time, harmonics from a normal incidence interaction. This was performed by using a special parabolic reflector with an on axis hole and is to allow measurements of the attosecond pulses using standard techniques. Here is a summary of the findings: First high harmonic generation in laser-solid interactions at 1021 Wcm-2, demonstration of harmonic focusing, study of ion motion effects in high harmonic generation in laser-solid interactions, and demonstration of harmonic amplification.

  4. A focusable, convergent fast-electron beam from ultra-high-intensity laser-solid interactions

    CERN Document Server

    Scott, R H H

    2015-01-01

    A novel scheme for the creation of a convergent, or focussing, fast-electron beam generated from ultra-high-intensity laser-solid interactions is described. Self-consistent particle-in-cell simulations are used to demonstrate the efficacy of this scheme in two dimensions. It is shown that a beam of fast-electrons of energy 500 keV - 3 MeV propagates within a solid-density plasma, focussing at depth. The depth of focus of the fast-electron beam is controlled via the target dimensions and focussing optics.

  5. Measurement of the relaxation time of hot electrons in laser-solid interaction at relativistic laser intensities

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H; Shepherd, R; Chung, H K; Dyer, G; Faenov, A; Fournier, K B; Hansen, S B; Hunter, J; Kemp, A; Pikuz, T; Ping, Y; Widmann, K; Wilks, S C; Beiersdorfer, P

    2006-08-22

    The authors have measured the relaxation time of hot electrons in short pulse laser-solid interactions using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. Employing laser intensities of 10{sup 17}, 10{sup 18}, and 10{sup 19} W/cm{sup 2}, they find increased laser coupling to hot electrons as the laser intensity becomes relativistic and thermalization of hot electrons at timescales on the order of 10 ps at all laser intensities. They propose a simple model based on collisional coupling and plasma expansion to describe the rapid relaxation of hot electrons. The agreement between the resulting K{sub {alpha}} time-history from this model with the experiments is best at highest laser intensity and less satisfactory at the two lower laser intensities.

  6. Effects of the plasma profiles on photon and pair production in ultrahigh intensity laser solid interaction

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Y. X.; Jin, X. L., E-mail: jinxiaolin@uestc.edu.cn; Yan, W. Z.; Li, J. Q.; Li, B. [Vacuum Electronics National Laboratory, University of Electronic Science and Technology of China, Chengdu 610054 (China); Yu, J. Q. [Vacuum Electronics National Laboratory, University of Electronic Science and Technology of China, Chengdu 610054 (China); John Adams Institute for Accelerator Science, Imperial College London, London SW7 2AZ (United Kingdom)

    2015-12-15

    The model of photon and pair production in strong field quantum electrodynamics is implemented into our 1D3V particle-in-cell code with Monte Carlo algorithm. Using this code, the evolution of the particles in ultrahigh intensity laser (∼10{sup 23} W/cm{sup 2}) interaction with aluminum foil target is observed. Four different initial plasma profiles are considered in the simulations. The effects of initial plasma profiles on photon and pair production, energy spectra, and energy evolution are analyzed. The results imply that one can set an optimal initial plasma profile to obtain the desired photon distributions.

  7. Front versus rear side light-ion acceleration from high-intensity laser-solid interactions

    Science.gov (United States)

    Willingale, L.; Petrov, G. M.; Maksimchuk, A.; Davis, J.; Freeman, R. R.; Matsuoka, T.; Murphy, C. D.; Ovchinnikov, V. M.; Van Woerkom, L.; Krushelnick, K.

    2011-01-01

    The source of ions accelerated from high-intensity laser interactions with thin foil targets is investigated by coating a deuterated plastic layer either on the front, rear or both surfaces of thin foil targets. The originating surface of the deuterons is therefore known and this method is used to assess the relative source contributions and maximum energies using a Thomson parabola spectrometer to obtain high-resolution light-ion spectra. Under these experimental conditions, laser intensity of (0.5-2.5) × 1019 W cm-2, pulse duration of 400 fs and target thickness of 6-13 µm, deuterons originating from the front surface can gain comparable maximum energies as those from the rear surface and spectra from either side can deviate from Maxwellian. Two-dimensional particle-in-cell simulations model the acceleration and show that any presence of a proton rich contamination layer over the surface is detrimental to the deuteron acceleration from the rear surface, whereas it is likely to be less influential on the front side acceleration mechanism.

  8. Effects of laser intensity on the emission direction of fast electrons in laser-solid interactions

    Institute of Scientific and Technical Information of China (English)

    张军; 张杰; 邱阳; 盛政明; 李玉同; 金展; 滕浩

    2003-01-01

    The dependence of emission direction of fast electrons on the laser intensity has been investigated. The experimental results show that, at nonrelativistic laser intensities, the emission of fast electrons is mainly in the polarization plane. With the increase of the laser intensity, fast electrons emit towards the laser propagation direction from laser polarization direction. At relativistic laser intensities, fast electrons move away from the laser polarization plane, closely to the reflection direction of the incident laser beam.

  9. Dissipative Structures At Laser-Solid Interactions

    Science.gov (United States)

    Nanai, Laszlo

    1989-05-01

    The questions which are discussed in this lecture refer to one of sections of laser-solid interactions, namely: to formation of different dissipative structures on the surface of metals and semiconductors when they are irradiated by intensive laser light in chemically active media (f.e.air). Some particular examples of the development at different spatial and time instabilities, periodic and stochastic structures, auto-wave processes are present-ed using testing materials vanadium metal and semiconducting V205 single crystals and light sources: cw and pulsed CO2 and YAG lasers.

  10. Scaling high-order harmonic generation from laser-solid interactions to ultrahigh intensity.

    Science.gov (United States)

    Dollar, F; Cummings, P; Chvykov, V; Willingale, L; Vargas, M; Yanovsky, V; Zulick, C; Maksimchuk, A; Thomas, A G R; Krushelnick, K

    2013-04-26

    Coherent x-ray beams with a subfemtosecond (scale length, which can strongly influence the harmonic generation mechanism. It is shown that for intensities in excess of 10(21)  W cm(-2) an optimum density ramp scale length exists that balances an increase in efficiency with a growth of parametric plasma wave instabilities. We show that for these higher intensities the optimal scale length is c/ω0, for which a variety of HOHG properties are optimized, including total conversion efficiency, HOHG divergence, and their power law scaling. Particle-in-cell simulations show striking evidence of the HOHG loss mechanism through parametric instabilities and relativistic self-phase modulation, which affect the produced spectra and conversion efficiency.

  11. High-repetition rate relativistic electron beam generation from intense laser solid interactions

    Science.gov (United States)

    Batson, Thomas; Nees, John; Hou, Bixue; Thomas, A. G. R.; Krushelnick, Karl

    2015-05-01

    Relativistic electron beams have applications spanning materials science, medicine, and home- land security. Recent advances in short pulse laser technology have enabled the production of very high focused intensities at kHz rep rates. Consequently this has led to the generation of high ux sources of relativistic electrons- which is a necessary characteristic of these laser plasma sources for any potential application. In our experiments, through the generation of a plasma with the lambda cubed laser system at the University of Michigan (a 5 × 1018W=cm2, 500 Hz, Ti:Sapphire laser), we have measured electrons ejected from the surface of fused silica nd Cu targets having energies in excess of an MeV. The spectrum of these electrons was measured with respect to incident laser angle, prepulse timing, and focusing conditions. While taken at a high repetition rate, the pulse energy of the lambda cubed system was consistently on the order of 10 mJ. In order to predict scaling of the electron energy with laser pulse energy, simulations are underway which compare the spectrum generated with the lambda cubed system to the predicted spectrum generated on the petawatt scale HERCULES laser system at the University of Michigan.

  12. Intense high repetition rate Mo Kα x-ray source generated from laser solid interaction for imaging application

    Energy Technology Data Exchange (ETDEWEB)

    Huang, K.; Li, M. H.; Yan, W. C.; Ma, Y.; Zhao, J. R.; Li, Y. F.; Chen, L. M., E-mail: lmchen@iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Guo, X. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190 (China); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); School of Optoelectronics, Beijing Institute of Technology, Beijing 100081 (China); Li, D. Z. [Institute of High Energy Physics, CAS, Beijing 100049 (China); Chen, Y. P.; Zhang, J. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2014-11-15

    We report an efficient Mo Kα x-ray source produced by interaction of femtosecond Ti: sapphire laser pulses with a solid Molybdenum target working at 1 kHz repetition rate. The generated Mo Kα x-ray intensity reaches to 4.7 × 10{sup 10} photons sr{sup −1} s{sup −1}, corresponding to an average power of 0.8 mW into 2π solid angle. The spatial resolution of this x-ray source is measured to be 26 lp/mm. With the high flux and high spatial resolution characteristics, high resolving in-line x-ray radiography was realized on test objects and large size biological samples within merely half a minute. This experiment shows the possibility of laser plasma hard x-ray source as a new low cost and high resolution system for radiography and its ability of ultrafast x-ray pump-probe study of matter.

  13. Effects of target pre-heating and expansion on terahertz radiation production from intense laser-solid interactions

    Institute of Scientific and Technical Information of China (English)

    X.H.Yuan; Y.Fang; D.C.Carroll; D.A.MacLellan; F.Du; N.Booth; M.Burza; M.Chen; R.J.Gray; Y.F.Jin; Y.T.Li; Y.Liu; D.Neely; H.Powell; G.Scott; C.-G.Wahlstrm; J.Zhang; P.McKenna; Z.M.Sheng

    2014-01-01

    The first experimental measurements of intense(~7 × 1019 W cm-2) laser-driven terahertz(THz) radiation from a solid target which is preheated by an intense pulse of laser-accelerated protons is reported. The total energy of the THz radiation is found to decrease by approximately a factor of 2 compared to a cold target reference. This is attributed to an increase in the scale length of the preformed plasma, driven by proton heating, at the front surface of the target,where the THz radiation is generated. The results show the importance of controlling the preplasma scale length for THz production.

  14. Generation of surface electrons in femtosecond laser-solid interactions

    Institute of Scientific and Technical Information of China (English)

    XU; Miaohua; LI; Yutong; YUAN; Xiaohui; ZHENG; Zhiyuan; LIANG; Wenxi; YU; Quanzhi; ZHANG; Yi; WANG; Zhaohua; WEI; Zhiyi; ZHANG; Jie

    2006-01-01

    The characteristics of hot electrons produced by p-polarized femtosecond laser-solid interactions are studied. The experimental results show that the outgoing electrons are mainly emitted in three directions: along the target surface, the normal direction and the laser backward direction. The electrons flowing along the target surface are due to the confinement of the electrostatic field and the surface magnetic field, while the electrons in the normal direction due to the resonant absorption.

  15. Measuring fast electron spectra and laser absorption in relativistic laser-solid interactions using differential bremsstrahlung photon detectors

    CERN Document Server

    Scott, R H H; Perez, F; Streeter, M J V; Davies, J R; Schlenvoigt, H -P; Santos, J J; Hulin, S; Lancaster, K L; Baton, S D; Rose, S J; Norreys, P A

    2013-01-01

    A photon detector suitable for the measurement of bremsstrahlung spectra generated in relativistically-intense laser-solid interactions is described. The Monte Carlo techniques used to back-out the fast electron spectrum and laser energy absorbed into fast electrons are detailed. A relativistically-intense laser-solid experiment using frequency doubled laser light is used to demonstrate the effective operation of the detector. The experimental data was interpreted using the 3-spatial-dimension Monte Carlo code MCNPX (Pelowitz 2008), and the fast electron temperature found to be 125 keV.

  16. Measuring fast electron spectra and laser absorption in relativistic laser-solid interactions using differential bremsstrahlung photon detectors.

    Science.gov (United States)

    Scott, R H H; Clark, E L; Pérez, F; Streeter, M J V; Davies, J R; Schlenvoigt, H-P; Santos, J J; Hulin, S; Lancaster, K L; Baton, S D; Rose, S J; Norreys, P A

    2013-08-01

    A photon detector suitable for the measurement of bremsstrahlung spectra generated in relativistically intense laser-solid interactions is described. The Monte Carlo techniques used to extract the fast electron spectrum and laser energy absorbed into forward-going fast electrons are detailed. A relativistically intense laser-solid experiment using frequency doubled laser light is used to demonstrate the effective operation of the detector. The experimental data were interpreted using the 3-spatial-dimension Monte Carlo code MCNPX [D. Pelowitz, MCNPX User's Manual Version 2.6.0, Los Alamos National Laboratory, 2008], and the fast electron temperature found to be 125 keV.

  17. Micron-scale Fast Electron Filamentation and Recirculation determined from Rear Side Optical Emission in High Intensity Laser-Solid Interactions

    CERN Document Server

    Bellei, C; Kar, S; Henig, A; Kneip, S; Palmer, C; Sävert, A; Willingale, L; Carroll, D; Dromey, B; Green, J S; Markey, K; Simpson, P; Clarke, R J; Lowe, H; Neely, D; Spindloe, C; Tolley, M; Kaluza, M; Mangles, S P D; McKenna, P; Norreys, P A; Schreiber, J; Zepf, M; Davies, J R; Krushelnick, K; Najmudin, Z

    2010-01-01

    The transport of relativistic electrons generated in the interaction of petawatt class lasers with solid targets has been studied through measurements of the optical emission from their rear surface. The high degree of polarization of the emission indicates that it is predominantly optical transition radiation. A halo that surrounds the main region of emission is also polarized, and is attributed to the effect of electron recirculation. The variation of the amplitude of the transition radiation with respect to observation angle provides evidence for the presence of {$\\mu$m-size} filaments.

  18. Photon dose estimation from ultraintense laser-solid interactions and shielding calculation with Monte Carlo simulation

    Science.gov (United States)

    Yang, Bo; Qiu, Rui; Li, JunLi; Lu, Wei; Wu, Zhen; Li, Chunyan

    2017-02-01

    When a strong laser beam irradiates a solid target, a hot plasma is produced and high-energy electrons are usually generated (the so-called "hot electrons"). These energetic electrons subsequently generate hard X-rays in the solid target through the Bremsstrahlung process. To date, only limited studies have been conducted on this laser-induced radiological protection issue. In this study, extensive literature reviews on the physics and properties of hot electrons have been conducted. On the basis of these information, the photon dose generated by the interaction between hot electrons and a solid target was simulated with the Monte Carlo code FLUKA. With some reasonable assumptions, the calculated dose can be regarded as the upper boundary of the experimental results over the laser intensity ranging from 1019 to 1021 W/cm2. Furthermore, an equation to estimate the photon dose generated from ultraintense laser-solid interactions based on the normalized laser intensity is derived. The shielding effects of common materials including concrete and lead were also studied for the laser-driven X-ray source. The dose transmission curves and tenth-value layers (TVLs) in concrete and lead were calculated through Monte Carlo simulations. These results could be used to perform a preliminary and fast radiation safety assessment for the X-rays generated from ultraintense laser-solid interactions.

  19. Study on the optimum parameters for laser-solid interaction

    Institute of Scientific and Technical Information of China (English)

    Liyun Lin(林丽云); Shengbo Wang(王声波); Dahao Guo(郭大浩); Hongxing Wu(吴鸿兴); Xiaoping Xia(夏小平); Yusheng Dai(戴宇生)

    2003-01-01

    The optimum parameters for laser propulsion are discussed, such as laser induced pressure on targets,interaction parameters (Cm, Isp) and optimum laser intensity Is, etc. It is verified that the larger laserpower density will induce higher thrusting force. It is also found that, to drive a 1.010-kg target duringconfined laser ablation in vacuum and a 17.45-g one during direct laser ablation in air at the standardpressure, the needed minimum power intensities are on the same order of magnitude.

  20. Modeling plasma plumes generated from laser solid interactions

    Science.gov (United States)

    Wilks, Scott C.; Higginson, D. P.; Link, A. J.; Park, H.-S.; Ping, Y.; Rinderknecht, H. G.; Ross, J. S.; Orban, C.; Hua, R.

    2016-10-01

    Laser pulses interacting with solid targets sitting in a vacuum form the basis for a large class of High Energy Density physics experiments. The resulting hydrodynamical evolution of the target during and after this interaction can be modeled using myriad techniques. These techniques range from pure particle-in-cell (PIC) to pure radiation-hydrodynamics, and include a large number of hybrid techniques in between. The particular method employed depends predominately on laser intensity. We compare and contrast several methods relevant for a large range of laser intensities (from Iλ2 1 ×1012W . μm2 /cm2 to Iλ2 1 ×1019W . μm2 /cm2) and energies (from E 100 mJ to E 100 kJ .) Density, temperature, and velocity profiles are benchmarked against recent experimental data. These experimental data include proton radiographs, time resolved x-ray images, and neutron yield and spectra. Methods to self-consistently handle backscatter and detailed energy deposition will also be discussed. LLNL-ABS-697767. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  1. Micron-Scale Mapping of Megagauss Magnetic Fields in Petawatt Laser-Solid Interactions

    CERN Document Server

    Chatterjee, Gourab; Robinson, A P L; Booth, N; Culfa, O; Dance, R J; Gizzi, L A; Gray, R J; Green, J S; Koester, P; Kumar, G Ravindra; Labate, L; Lad, Amit D; Lancaster, K L; Pasley, J; Woolsey, N C; Rajeev, P P

    2013-01-01

    We report spatially and temporally resolved measurements of magnetic fields generated by petawatt laser-solid interactions with high spatial resolution, using optical polarimetry. The polarimetric measurements map the megagauss magnetic field profiles generated by the fast electron currents at the target rear. The magnetic fields at the rear of a 50 $\\mu$m thick aluminum target exhibit distinct and unambiguous signatures of electron beam filamentation. These results are corroborated by hybrid simulations.

  2. Current scaling and plasma heating in relativistic laser-solid interaction

    CERN Document Server

    Kluge, Thomas; Huang, Lingen; Metzkes, Josefine; Cowan, Thomas E; Schramm, Ulrich

    2015-01-01

    Intense and energetic electron currents can be generated by ultra-intense lasers interacting with solid density targets. Especially for ultra-short laser pulses their temporal evolution needs to be taken into account for many non-linear processes as instantaneous currents may differ significantly from the average. Hence, a dynamic model including the temporal variation of the electron currents which goes beyond a simple bunching with twice the laser frequency but otherwise constant current is needed. Here we present a new time-dependent model to describe the laser generated currents and obtain simple expressions for the temporal evolution and resulting corrections of averages. To exemplify the model and its predictive capabilities we show the impact of temporal evolution, spectral distribution and spatial modulations on Ohmic heating of the bulk target material.

  3. Terahertz emission from two-plasmon-decay induced transient currents in laser-solid interactions

    Energy Technology Data Exchange (ETDEWEB)

    Liao, G.-Q.; Li, C. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Y.-T., E-mail: ytli@iphy.ac.cn, E-mail: zmsheng@sjtu.edu.cn; Wang, W.-M. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China); Mondal, S.; Hafez, H. A.; Fareed, M. A.; Ozaki, T. [INRS-EMT, 1650 Boulevard Lionel-Boulet, Varennes, Québec J3X 1S2 (Canada); Sheng, Z.-M., E-mail: ytli@iphy.ac.cn, E-mail: zmsheng@sjtu.edu.cn [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China); Zhang, J. [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China)

    2016-01-15

    We have studied the generation of terahertz (THz) radiation via the interaction of intense femtosecond laser pulses with solid targets at a small incidence angle. It is found that preplasma with a moderate density gradient can enhance the emission. We also observe saturation of the THz output with the driving laser energy. We find that THz emission is closely related to the 3/2 harmonics of the driving laser. Particle-in-cell simulations indicate that under the present experimental conditions, the THz emission could be attributed to the transient currents at the plasma-vacuum interface, mainly formed by the two-plasmon-decay instability.

  4. Ultrahigh-current proton beams from short-pulse laser-solid interactions

    Energy Technology Data Exchange (ETDEWEB)

    Badziak, J; Jablowski, S; Parys, P; Rosinski, M; Suchanska, R; Wolowski, J [Institute of Plasma Physics and Laser Microfusion, EURATOM Association, Warsaw (Poland); Antici, P; Fuchs, J; Lancia, L; Mancic, A [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, Route de Saclay, 91128 Palaiseau (France); Szydlowski, A [Andrzej Soltan Institute for Nuclear Studies, Warsaw (Poland)], E-mail: badziak@ifpilm.waw.pl

    2008-05-01

    The results of studies of high-current proton beam generation from thin (1-3{mu}m) solid targets irradiated by 0.35-ps laser pulse of intensity up to 2x10{sup 19} W/cm{sup 2} are reported. It is shown that the proton beams of multi-MA currents and multi-TA/cm{sup 2} current densities at the source can be produced when the laser-target interaction conditions approach the skin-layer ponderomotive acceleration requirements. The current and energy spectrum of protons remarkably depend on the target structure. In particular, using a double-layer Au/PS target (plastic covered by 0.1 - 0.2{mu}m Au front layer) results in two-fold higher proton currents and higher proton energies than in the case of a plastic target.

  5. Weibel magnetic field competes with Biermann fields in laser-solid interactions

    Science.gov (United States)

    Shukla, Nitin; Schoeffler, Kevin; Vieira, Jorge; Fonseca, Ricardo; Silva, Luis

    2016-10-01

    Biermann battery induced magnetic fields caused by non-parallel density and temperature gradients, first investigated experimentally, continue to be measured in many current experiments. A detailed study of Biermann generated magnetic fields in collisionless systems has been carried out, showing that for large system sizes (L /de >= 100) , where de is the electron inertial length, the Weibel instability dominates as the major source of magnetic field. In this work, we demonstrate the possibility of experimentally generating this strong Weibel magnetic field. We model, using ab initio PIC simulations, the interaction of a short (ps) high intensity (a0 >= 1) laser pulse, with a target of sufficiently large gradient scale length, L. The expanding hot energetic electron population generated by the laser produces an anisotropy in the velocity distribution. This anisotropy provides the free energy that drives the Weibel instability that appears on the surfaces of the target and dominates over the Biermann battery field.

  6. Unexpected generation of super-high energetic electrons at relativistic circularly polarized laser-solid interactions in the presence of large scale pre-plasmas

    CERN Document Server

    Wu, D; Luan, S X; Yu, W

    2015-01-01

    As a continuation of the previous work "Identifying the source of super-high energetic electrons in the presence of pre-plasma in laser-matter interaction at relativistic intensities [arXiv: 1512.02411]", we have investigated the role of circularly polarized (CP) laser pulses while keeping other conditions the same. It is found that in the presence of large scale pre-formed plasmas, super-high energetic electrons can be generated at relativistic CP laser-solid interactions. For laser of intensity 10$^{20}\\ $W$/$cm$^2$ and pre-plasma scale-length 10$\\ \\mu$m, the cut-off energy of electron by CP laser is 120$\\ $MeV compared with 100$\\ $MeV in the case of linearly polarized (LP) laser. The unexpected super-high energetic electron acceleration can also be explained by the two-stage acceleration model, by considering the polarization transition of the reflected laser from CP to elliptically polarized (EP). The polarization state transition is addressed, and a modified scaling law in the presence of EP laser is obt...

  7. Longitudinal proton probing of ultrafast and high-contrast laser-solid interactions

    Directory of Open Access Journals (Sweden)

    Albertazzi B.

    2013-11-01

    Full Text Available We have performed an experiment aimed at measuring self-generated magnetic fields produced in solids by high electron currents following high-intensity and high contrast short-pulse laser irradiation. This was done using longitudinal high resolution proton deflectometry. The experiment was performed at the Titan-JLF laser facility with a high-power short-pulse beam (700 fs, ∼  110 J split into two beams irradiating two solid targets. One beam is used for the generation of protons and the other beam for the generation of the ultra-high currents of electrons and of the associated magnetic fields. This capability allows us to study the spatio-temporal evolution of the magnetic fields and its dependence on the laser intensity and target material.

  8. Demonstration of Coherent Terahertz Transition Radiation from Relativistic Laser-Solid Interactions

    Science.gov (United States)

    Liao, Guo-Qian; Li, Yu-Tong; Zhang, Yi-Hang; Liu, Hao; Ge, Xu-Lei; Yang, Su; Wei, Wen-Qing; Yuan, Xiao-Hui; Deng, Yan-Qing; Zhu, Bao-Jun; Zhang, Zhe; Wang, Wei-Min; Sheng, Zheng-Ming; Chen, Li-Ming; Lu, Xin; Ma, Jing-Long; Wang, Xuan; Zhang, Jie

    2016-05-01

    Coherent transition radiation in the terahertz (THz) region with energies of sub-mJ/pulse has been demonstrated by relativistic laser-driven electron beams crossing the solid-vacuum boundary. Targets including mass-limited foils and layered metal-plastic targets are used to verify the radiation mechanism and characterize the radiation properties. Observations of THz emissions as a function of target parameters agree well with the formation-zone and diffraction model of transition radiation. Particle-in-cell simulations also well reproduce the observed characteristics of THz emissions. The present THz transition radiation enables not only a potential tabletop brilliant THz source, but also a novel noninvasive diagnostic for fast electron generation and transport in laser-plasma interactions.

  9. RADIATION DOSE MEASUREMENTS FOR HIGH-INTENSITY LASER INTERACTIONS WITH SOLID TARGETS AT SLAC.

    Science.gov (United States)

    Liang, T; Bauer, J; Cimeno, M; Ferrari, A; Galtier, E; Granados, E; Lee, H J; Liu, J; Nagler, B; Prinz, A; Rokni, S; Tran, H; Woods, M

    2016-12-01

    A systematic study of photon and neutron radiation doses generated in high-intensity laser-solid interactions is underway at SLAC National Accelerator Laboratory. These laser-solid experiments are being performed using a 25 TW (up to 1 J in 40 fs) femtosecond pulsed Ti:sapphire laser at the Linac Coherent Light Source's (LCLS) Matter in Extreme Conditions (MEC) facility. Radiation measurements were performed with passive and active detectors deployed at various locations inside and outside the target chamber. Results from radiation dose measurements for laser-solid experiments at SLAC MEC in 2014 with peak intensity between 10(18) and 7.1 × 10(19) W cm(-2) are presented.

  10. Radiation Dose Measurement for High-Intensity Laser Interactions with Solid Targets at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Taiee [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-09-25

    A systematic study of photon and neutron radiation doses generated in high-intensity laser-solid interactions is underway at SLAC National Accelerator Laboratory. We found that these laser-solid experiments are being performed using a 25 TW (up to 1 J in 40 fs) femtosecond pulsed Ti:sapphire laser at the Linac Coherent Light Source’s (LCLS) Matter in Extreme Conditions (MEC) facility. Additionally, radiation measurements were performed with passive and active detectors deployed at various locations inside and outside the target chamber. Results from radiation dose measurements for laser-solid experiments at SLAC MEC in 2014 with peak intensity between 1018 to 7.1x1019 W/cm2 are presented.

  11. The controllable super-high energetic electrons by external magnetic fields at relativistic laser-solid interactions in the presence of large scale pre-plasmas

    CERN Document Server

    Wu, D; Luan, S X; Yu, W

    2016-01-01

    The two stage electron acceleration model [arXiv: 1512.02411 and arXiv: 1512.07546] is extended to the study of laser magnetized-plasmas interactions at relativistic intensities and in the presence of large-scale preformed plasmas. It is shown that the cut-off electron kinetic energy is controllable by the external magnetic field strength and directions. Further studies indicate that for a right-hand circularly polarized laser (RH-CP) of intensity $10^{20}\\ \\text{W}/\\text{cm}^2$ and pre-plasma scale length $10\\ \\mu\\text{m}$, the cut-off electron kinetic energy can be as high as $500\\ \\text{MeV}$, when a homogeneous external magnetic field of exceeding $10000\\ \\text{T}$ (or $B=\\omega_{c}/\\omega_0>1$) is loaded along the laser propagation direction, which is a significant increase compared with that $120\\ \\text{MeV}$ without external magnetic field. A laser front sharpening mechanism is identified at relativistic laser magnetized-plasmas interactions with $B=\\omega_{c}/\\omega_0>1$, which is responsible for thes...

  12. Micron-scale mapping of megagauss magnetic fields using optical polarimetry to probe hot electron transport in petawatt-class laser-solid interactions.

    Science.gov (United States)

    Chatterjee, Gourab; Singh, Prashant Kumar; Robinson, A P L; Blackman, D; Booth, N; Culfa, O; Dance, R J; Gizzi, L A; Gray, R J; Green, J S; Koester, P; Kumar, G Ravindra; Labate, L; Lad, Amit D; Lancaster, K L; Pasley, J; Woolsey, N C; Rajeev, P P

    2017-08-21

    The transport of hot, relativistic electrons produced by the interaction of an intense petawatt laser pulse with a solid has garnered interest due to its potential application in the development of innovative x-ray sources and ion-acceleration schemes. We report on spatially and temporally resolved measurements of megagauss magnetic fields at the rear of a 50-μm thick plastic target, irradiated by a multi-picosecond petawatt laser pulse at an incident intensity of ~10(20) W/cm(2). The pump-probe polarimetric measurements with micron-scale spatial resolution reveal the dynamics of the magnetic fields generated by the hot electron distribution at the target rear. An annular magnetic field profile was observed ~5 ps after the interaction, indicating a relatively smooth hot electron distribution at the rear-side of the plastic target. This is contrary to previous time-integrated measurements, which infer that such targets will produce highly structured hot electron transport. We measured large-scale filamentation of the hot electron distribution at the target rear only at later time-scales of ~10 ps, resulting in a commensurate large-scale filamentation of the magnetic field profile. Three-dimensional hybrid simulations corroborate our experimental observations and demonstrate a beam-like hot electron transport at initial time-scales that may be attributed to the local resistivity profile at the target rear.

  13. A diagnostic for micrometer sensitive positioning of solid targets in intense laser-matter interaction

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Prashant Kumar, E-mail: singh01@ibs.re.kr [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kakolee, K.F. [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Jeong, T.W. [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of); Ter-Avetisyan, Sargis, E-mail: sargis@ibs.re.kr [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

    2016-09-01

    A target position monitoring diagnostic, relevant to intense laser-solid interaction, is presented. The alignment system, having a sensitivity of few micrometers, consist of an infinity corrected long working distance objective, a broadband illuminating source and a CCD camera. The imaging system, placed along the axis of incident laser pulse, serves the dual purpose of laser focus diagnosis and precise positioning of the target in three dimension axis. By employing this technique, solid targets with thickness varying from opaque micrometer thick foils to few nanometer thin transparent foils can be aligned precisely. The effectiveness of the entire alignment system is demonstrated in enhanced acceleration of ions in intense laser-matter interaction, with very high reproducibility.

  14. Investigation of the effect of laser parameters on the target, plume and plasma behavior during and after laser-solid interaction

    Science.gov (United States)

    Stancalie, A.; Ciobanu, S. S.; Sporea, D.

    2017-09-01

    A detailed theoretical and experimental analysis is performed for a wide range of laser operating conditions, typical for laser induced breakdown spectroscopy (LIBS) and laser ablation (LA) experiments on copper metallic target. The plasma parameters were experimentally estimated from the line intensities ratio which reflects the relative population of neutral excited species in the plasma. In the case of LA experiments the highest temperature observed was 8210 ± 370 K. In case of LIBS measurements, a maximum temperature of 8123 K has been determined. The experimental results are in good agreement with a stationary, hydrodynamic model. We have theoretically investigated the plasma emission based on the generalized collisional-radiative model as implemented in the ADAS interconnected set of computer codes and data collections. The ionic population density distribution over the ground and excited states into the cooper plasma is graphically displayed as output from the code. The theoretical line intensity ratios are in good agreement with experimental values for the electron density and temperature range measured in our experiments.

  15. Imitation, Interaction and Dialogue Using Intensive Interaction: Tea Party Rules

    Science.gov (United States)

    Barber, Mark

    2007-01-01

    Intensive Interaction has become widely used when building up communication with children with profound learning difficulties. Often practitioners understand Intensive Interaction to be primarily about imitation and Mark Barber shows how this can be a "mis"understanding that limits the kinds of interactions that can be enjoyed by conversation…

  16. Gamma-ray emission in ultra-intense laser interaction with solid targets

    Science.gov (United States)

    Klimo, Ondrej; Vyskocil, Jiri; Kumar, Deepak; Limpouch, Jiri; Weber, Stefan

    2016-10-01

    Electrons moving in ultra-intense laser fields emit hard radiation due to radiation reaction and non-linear Compton scattering. Multi-MeV γ-rays were measured by scattering of electrons generated from laser wakefield with a focused laser of intensity a0 1 . However, non-linear Compton scattering and radiation reaction is also an efficient mechanism for generating copious amount of γ-rays in laser interaction with solids at intensities approaching 1022 W/cm2. Emission of γ-rays due to radiation reaction and bremsstrahlung are investigated here in the high intensity regime of laser-solid target interaction by using a combination of Particle-in-Cell and Monte Carlo radiation transport simulations. The relative contribution of these processes is analyzed as a function of the target parameters. We concentrate on the influence of the target thickness, material, preplasma conditions or a surface structure on the generation of high energy photons and study separately their energy and angular distributions. It is demonstrated that the presence of preplasma or a special surface structure may significantly enhance emission of hard γ photons and their cut-off energy and change their angular distribution. Supported by Czech Science Foundation project 15-02964S.

  17. Laser Ion Acceleration from the Interaction of Ultra-Intense laser Pulse with thi foils

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Matthew Mark [Univ. of California, Berkeley, CA (United States)

    2004-03-12

    The discovery that ultra-intense laser pulses (I > 1018 W/cm2) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I > 1018 W/cm2), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by Up = ([1 + Iλ2/1.3 x 1018]1/2 - 1) moc2, where Iλ2 is the irradiance in Wμm2/cm2 and moc2 is the electron rest mass.At laser irradiance of Iλ2 ~ 1018 Wμm2/cm2, the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the front surface of the target to energies up to tens of MeV. Another model, known as Target Normal Sheath Acceleration (TNSA), describes the mechanism as an electrostatic sheath on the back surface of the laser target. According to the TNSA model, relativistic hot electrons created at the laser-solid interaction penetrate the foil where a few escape to infinity. The remaining hot electrons are retained by the target potential and establish an electrostatic sheath on the back surface of the target.

  18. Potential intravenous drug interactions in intensive care

    Directory of Open Access Journals (Sweden)

    Maiara Benevides Moreira

    Full Text Available Abstract OBJECTIVE To analyze potential intravenous drug interactions, and their level of severity associated with the administration of these drugs based on the prescriptions of an intensive care unit. METHOD Quantitative study, with aretrospective exploratory design, and descriptive statistical analysis of the ICU prescriptions of a teaching hospital from March to June 2014. RESULTS The sample consisted of 319 prescriptions and subsamples of 50 prescriptions. The mean number of drugs per patient was 9.3 records, and a higher probability of drug interaction inherent to polypharmacy was evidenced. The study identified severe drug interactions, such as concomitant administration of Tramadol with selective serotonin reuptake inhibitor drugs (e.g., Metoclopramide and Fluconazole, increasing the risk of seizures due to their epileptogenic actions, as well as the simultaneous use of Ranitidine-Fentanyl®, which can lead to respiratory depression. CONCLUSION A previous mapping of prescriptions enables the characterization of the drug therapy, contributing to prevent potential drug interactions and their clinical consequences.

  19. Interaction intensity and pollinator-mediated selection.

    Science.gov (United States)

    Trunschke, Judith; Sletvold, Nina; Ågren, Jon

    2017-02-27

    In animal-pollinated plants, the opportunity for selection and the strength of pollinator-mediated selection are expected to increase with the degree of pollen limitation. However, whether differences in pollen limitation can explain variation in pollinator-mediated and net selection among animal-pollinated species is poorly understood. In the present study, we quantified pollen limitation, variance in relative fitness and pollinator-mediated selection on five traits important for pollinator attraction (flowering start, plant height, flower number, flower size) and pollination efficiency (spur length) in natural populations of 12 orchid species. Pollinator-mediated selection was quantified by subtracting estimates of selection gradients for plants receiving supplemental hand-pollination from estimates obtained for open-pollinated control plants. Mean pollen limitation ranged from zero to 0.96. Opportunity for selection, pollinator-mediated selection and net selection were all positively related to pollen limitation, whereas nonpollinator-mediated selection was not. Opportunity for selection varied five-fold, strength of pollinator-mediated selection varied three-fold and net selection varied 1.5-fold among species. Supplemental hand-pollination reduced both opportunity for selection and selection on floral traits. The results show that the intensity of biotic interactions is an important determinant of the selection regime, and indicate that the potential for pollinator-mediated selection and divergence in floral traits is particularly high in species that are strongly pollen-limited.

  20. A Dual Aspect Process Model of Intensive Interaction

    Science.gov (United States)

    Firth, Graham

    2009-01-01

    Intensive Interaction is an empirically researched approach to developing fundamental communication and sociability for people with severe and profound learning disabilities and/or autism. However, it is the author's contention that certain aspects of Intensive Interaction are not universally conceptualised in a uniform manner, and that there are…

  1. Microengineering laser plasma interactions at relativistic intensities

    OpenAIRE

    S. Jiang; Ji,L.L.; Audesirk, H.; George, K M; Snyder, J.; Krygier, A.; Lewis, N. S.; Schumacher, D. W.; Pukhov, A.; Freeman, R. R.; Akli, K. U.

    2015-01-01

    We report on the first successful proof-of-principle experiment to manipulate laser-matter interactions on the microscale using highly ordered Si microwire arrays. The interaction of a high contrast short pulse laser with a flat target via periodic Si microwires yields a substantial enhancement in both total and cut-off energies of the produced electron beam. The self generated electric and magnetic fields behave as an electromagnetic lens that confines and guides electrons between the microw...

  2. Microengineering laser plasma interactions at relativistic intensities

    CERN Document Server

    Jiang, S; Audesirk, H; George, K M; Snyder, J; Krygier, A; Lewis, N S; Schumacher, D W; Pukhov, A; Freeman, R R; Akli, K U

    2015-01-01

    We report on the first successful proof-of-principle experiment to manipulate laser-matter interactions on the microscale using highly ordered Si microwire arrays. The interaction of a high contrast short pulse laser with a flat target via periodic Si microwires yields a substantial enhancement in both total and cut-off energies of the produced electron beam. The self generated electric and magnetic fields behave as an electromagnetic lens that confines and guides electrons between the microwires as they acquire relativistic energies via direct laser acceleration (DLA).

  3. Microengineering Laser Plasma Interactions at Relativistic Intensities.

    Science.gov (United States)

    Jiang, S; Ji, L L; Audesirk, H; George, K M; Snyder, J; Krygier, A; Poole, P; Willis, C; Daskalova, R; Chowdhury, E; Lewis, N S; Schumacher, D W; Pukhov, A; Freeman, R R; Akli, K U

    2016-02-26

    We report on the first successful proof-of-principle experiment to manipulate laser-matter interactions on microscales using highly ordered Si microwire arrays. The interaction of a high-contrast short-pulse laser with a flat target via periodic Si microwires yields a substantial enhancement in both the total and cutoff energies of the produced electron beam. The self-generated electric and magnetic fields behave as an electromagnetic lens that confines and guides electrons between the microwires as they acquire relativistic energies via direct laser acceleration.

  4. Intense Magnetized Plasma-Wall Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Bruno S. [UNR; Fuelling, Stephan [UNR

    2013-11-30

    This research project studied wall-plasma interactions relevant to fusion science. Such interactions are a critical aspect of Magneto-Inertial Fusion (MIF) because flux compression by a pusher material, in particular the metal for the liner approach to MIF, involves strong eddy current heating on the surface of the pusher, and probably interactions and mixing of the pusher with the interior fuel during the time when fusion fuel is being burned. When the pusher material is a metal liner, high-energy-density conditions result in fascinating behavior. For example, "warm dense matter" is produced, for which material properties such as resistivity and opacity are not well known. In this project, the transformation into plasma of metal walls subjected to pulsed megagauss magnetic fields was studied with an experiment driven by the UNR 1 MA Zebra generator. The experiment was numerically simulated with using the MHRDR code. This simple, fundamental high-energy-density physics experiment, in a regime appropriate to MIF, has stimulated an important and fascinating comparison of numerical modeling codes and tables with experiment. In addition, we participated in developing the FRCHX experiment to compress a field-reversed-configuration (FRC) plasma with a liner, in collaboration with researchers from Air Force Research Laboratory and Los Alamos National Lab, and we helped develop diagnostics for the Plasma Liner Experiment (PLX) at LANL. Last, but not least, this project served to train students in high-energy-density physics.

  5. Experimental reduction in interaction intensity strongly affects biotic selection.

    Science.gov (United States)

    Sletvold, Nina; Ågren, Jon

    2016-11-01

    The link between biotic interaction intensity and strength of selection is of fundamental interest for understanding biotically driven diversification and predicting the consequences of environmental change. The strength of selection resulting from biotic interactions is determined by the strength of the interaction and by the covariance between fitness and the trait under selection. When the relationship between trait and absolute fitness is constant, selection strength should be a direct function of mean population interaction intensity. To test this prediction, we excluded pollinators for intervals of different length to induce five levels of pollination intensity within a single plant population. Pollen limitation (PL) increased from 0 to 0.77 across treatments, accompanied by a fivefold increase in the opportunity for selection. Trait-fitness covariance declined with PL for number of flowers, but varied little for other traits. Pollinator-mediated selection on plant height, corolla size, and spur length increased by 91%, 34%, and 330%, respectively, in the most severely pollen-limited treatment compared to open-pollinated plants. The results indicate that realized biotic selection can be predicted from mean population interaction intensity when variation in trait-fitness covariance is limited, and that declines in pollination intensity will strongly increase selection on traits involved in the interaction. © 2016 by the Ecological Society of America.

  6. Biotic interaction strength and the intensity of selection.

    Science.gov (United States)

    Benkman, Craig W

    2013-08-01

    Although the ecological and evolutionary impacts of species interactions have been the foci of much research, the relationship between the strength of species interactions and the intensity of selection has been investigated only rarely. I develop a simple model demonstrating how the opportunity for selection varies with interaction strength, and then use the relationship between the maximum value of the selection differential and the opportunity for selection (Arnold & Wade 1984) to evaluate how selection differentials vary in relation to species interaction strength. This model predicts an initial deceleration and then an accelerating increase in the intensity of selection with increasing strength of antagonistic interactions and with decreasing strength of mutualistic interactions. Empirical data from several studies provide support for this model. These results further support an evolutionary mechanism for some striking patterns of evolutionary diversification including the latitudinal species gradient, and should be relevant to studies of eco-evolutionary dynamics.

  7. High-Intensity Femtosecond Laser Interaction with Rare Gas Clusters

    Institute of Scientific and Technical Information of China (English)

    林亚风; 钟钦; 曾淳; 陈哲

    2001-01-01

    With a 45 fs multiterawatt 790 nm laser system and jets of argon and krypton atomic clusters, a study of the interaction of fs intense laser pulses with large size rare gas dusters was conducted. The maximum laser intensity of about 7 × 1016 W/cm2 and dusters composed of thousands of atoms which were determined through Rayleigh scattering measurements were involved inthe experiments. On the one hand, the results indicate that the interaction is strongly cluster size dependent. The stronger the interaction, the larger the clusters are. On the other hand, a saturation followed by a drop of the energy of ions ejected from the interaction will occur when the laser intensity exceeds a definite value for clusters of a certain size.

  8. Ion Acceleration from the Interaction of Ultra-Intense Lasers with Solid Foils

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Matthew M. [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    The discovery that ultra-intense laser pulses (I > 1018 W/cm2) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I > 1018 W/cm2), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by Up = ([1 + Iλ2/1.3 x 1018]1/2 - 1) m{sub o}c2, where Iλ2 is the irradiance in W μm2/cm2 and moc2 is the electron rest mass. At laser irradiance of Iλ2 ~ 1020 W μm2/cm2, the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the front surface of the target to energies up to tens of MeV. Another model, known as Target Normal Sheath Acceleration (TNSA), describes the mechanism as an electrostatic sheath on the back surface of the laser target. According to the TNSA model, relativistic hot electrons created at the laser-solid interaction penetrate the foil where a few escape to infinity. The remaining hot electrons are retained by the target potential and establish an electrostatic sheath on the back surface of the target. In this thesis we present several experiments that study the accelerated ions by

  9. Intense terahertz radiation from relativistic laser-plasma interactions

    Science.gov (United States)

    Liao, G. Q.; Li, Y. T.; Li, C.; Liu, H.; Zhang, Y. H.; Jiang, W. M.; Yuan, X. H.; Nilsen, J.; Ozaki, T.; Wang, W. M.; Sheng, Z. M.; Neely, D.; McKenna, P.; Zhang, J.

    2017-01-01

    The development of tabletop intense terahertz (THz) radiation sources is extremely important for THz science and applications. This paper presents our measurements of intense THz radiation from relativistic laser-plasma interactions under different experimental conditions. Several THz generation mechanisms have been proposed and investigated, including coherent transition radiation (CTR) emitted by fast electrons from the target rear surface, transient current radiation at the front of the target, and mode conversion from electron plasma waves (EPWs) to THz waves. The results indicate that relativistic laser plasma is a promising driver of intense THz radiation sources.

  10. Changing intensity of interaction can resolve prisoner's dilemmas

    Science.gov (United States)

    Li, Jiaqi; Zhang, Chunyan; Sun, Qinglin; Chen, Zengqiang; Zhang, Jianlei

    2016-03-01

    We put forward a computational model which mainly focuses on the effect of changing the intensity of interaction between individuals to study the evolutionary prisoner's dilemma game in social networks. In this model, an individual will unilaterally increase the intensity of interaction from it to some of its neighbors in case it is satisfied with the current income which it obtains from the neighbor; conversely, the individual will unilaterally reduce the intensity of interaction from it to its neighbor. We show that this simple evolutionary rule can effectively shift the survival barrier of cooperators and drastically facilitate the emergence of cooperation. Interestingly, for a fixed temptation to defect, there exists the smallest increment of intensity of interaction, resulting in a plateau of high cooperation level due to the positive feedback mechanism. Furthermore, we find good agreement between simulation results and theoretical predictions obtained from an extended pair-approximation method. Meanwhile, we illustrate the dynamical evolution of cooperators on the network, and investigate the impact of noise during the strategy updates.

  11. The Effectiveness of Intensive Interaction, A Systematic Literature Review

    Science.gov (United States)

    Hutchinson, Nick; Bodicoat, Anna

    2015-01-01

    Background: Intensive Interaction is an approach used for communicating with people with profound and multiple intellectual disabilities [PMID] or autism. It has gained increased recognition as a helpful technique, but the evidence has not been systematically reviewed. Method: Computerized and hand searches of the literature were conducted using…

  12. Effects of radiation damping in ultra-intense laser matter interaction at extreme intensity regime

    Science.gov (United States)

    Sentoku, Yasuhiko; Pandit, Rishi

    2011-10-01

    Effects of the radiation damping in the interaction of extremely intense laser (>1022 W/cm2) with metal targets are studied via a relativistic collisional particle- in-cell simulation, PICLS. We had introduced the Landau-Lifshitz equation, which is the first order term of the Lorentz-Dirac equation to PIC, and also derived the second order term to check its effect. We had implemented these damping terms in the two- dimensional PICLS code, and had studied the laser plasma interaction at >1022 W/cm2 intensities. Hot electrons generated by such extreme-intense laser lights on the target get the relativistic energy with relativistic Lorentz factor γ > 100 , and lose energy strongly by emitting radiations. Especially, we had studied the second term's effect in a comparison with the first order damping term, and found that the second term becomes comparable to the first order term when the laser intensity >1023 W/cm2. With the higher order term, the hot electrons with energies greater than 500 MeV are totally suppressed and hard them to go beyond that energy even increasing the laser intensity >1023 W/cm2. Supported by US DOE DE-PS02-08ER08-16 and DE-FC02-04ER54789.

  13. The radiation reaction effect in ultra intense laser foil interactions

    Science.gov (United States)

    Klimo, O.; Jirka, M.; Masek, M.; Limpouch, J.; Bussmann, M.; Korn, G.

    2013-05-01

    Since the radiation reaction effect on electron propagation is very small in most cases, it can be usually neglected and the Lorentz force equation can be applied. However, ultra-intense lasers with normalized vector potential of the order of 100 can accelerate electrons to relativistic velocities with very high gamma factor. When the electron is accelerated to such high velocities the amount of emitted radiation may become large and radiation damping and emission of energetic photons should be considered. This work studies the influence of the radiation reaction force on laser interaction with solid foil targets. It compares different approaches adopted in PIC simulations to take into account the radiation reaction. The simulations of a counter-propagating relativistic electron and an ultra-intense laser beam demonstrate a strong energy loss of electrons due to non-linear Compton scattering. The interaction of ultra-intense laser pulse with solid foil is studied using PIC simulations. It is shown that the effect of radiation reaction strongly depends on the recirculation of high-energy electrons. When the recirculation is efficient, the radiation coming from the target is much more intense and it shows different spectral and angular characteristics.

  14. Extremely high-intensity laser interactions with fundamental quantum systems

    CERN Document Server

    Di Piazza, A; Hatsagortsyan, K Z; Keitel, C H

    2011-01-01

    The field of laser-matter interaction traditionally deals with the response of atoms, molecules and plasmas to an external light wave. However, the recent sustained technological progress is opening the possibility of employing intense laser radiation to prompt or substantially influence physical processes beyond atomic-physics energy scales. Available optical laser intensities exceeding $10^{22}\\;\\text{W/cm$^2$}$ can push the fundamental light-electron interaction to the extreme limit where radiation-reaction effects dominate the electron dynamics, can shed light on the structure of the quantum vacuum and can prime the creation of particles like electrons, muons and pions and the corresponding antiparticles. Also, novel sources of intense coherent high-energy photons and laser-based particle colliders can pave the way to nuclear quantum optics and can even allow for potential discovery of new particles beyond the Standard Model. These are the main topics of the present article, which is devoted to a review o...

  15. The interaction of intense subpicosecond laser pulses with underdense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Coverdale, C.A.

    1995-05-11

    Laser-plasma interactions have been of interest for many years not only from a basic physics standpoint, but also for their relevance to numerous applications. Advances in laser technology in recent years have resulted in compact laser systems capable of generating (psec), 10{sup 16} W/cm{sup 2} laser pulses. These lasers have provided a new regime in which to study laser-plasma interactions, a regime characterized by L{sub plasma} {ge} 2L{sub Rayleigh} > c{tau}. The goal of this dissertation is to experimentally characterize the interaction of a short pulse, high intensity laser with an underdense plasma (n{sub o} {le} 0.05n{sub cr}). Specifically, the parametric instability known as stimulated Raman scatter (SRS) is investigated to determine its behavior when driven by a short, intense laser pulse. Both the forward Raman scatter instability and backscattered Raman instability are studied. The coupled partial differential equations which describe the growth of SRS are reviewed and solved for typical experimental laser and plasma parameters. This solution shows the growth of the waves (electron plasma and scattered light) generated via stimulated Raman scatter. The dispersion relation is also derived and solved for experimentally accessible parameters. The solution of the dispersion relation is used to predict where (in k-space) and at what frequency (in {omega}-space) the instability will grow. Both the nonrelativistic and relativistic regimes of the instability are considered.

  16. The interaction of intense subpicosecond laser pulses with underdense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Coverdale, Christine Ann [Univ. of California, Davis, CA (United States)

    1995-05-11

    Laser-plasma interactions have been of interest for many years not only from a basic physics standpoint, but also for their relevance to numerous applications. Advances in laser technology in recent years have resulted in compact laser systems capable of generating (psec), 1016 W/cm2 laser pulses. These lasers have provided a new regime in which to study laser-plasma interactions, a regime characterized by Lplasma ≥ 2LRayleigh > cτ. The goal of this dissertation is to experimentally characterize the interaction of a short pulse, high intensity laser with an underdense plasma (no ≤ 0.05ncr). Specifically, the parametric instability known as stimulated Raman scatter (SRS) is investigated to determine its behavior when driven by a short, intense laser pulse. Both the forward Raman scatter instability and backscattered Raman instability are studied. The coupled partial differential equations which describe the growth of SRS are reviewed and solved for typical experimental laser and plasma parameters. This solution shows the growth of the waves (electron plasma and scattered light) generated via stimulated Raman scatter. The dispersion relation is also derived and solved for experimentally accessible parameters. The solution of the dispersion relation is used to predict where (in k-space) and at what frequency (in ω-space) the instability will grow. Both the nonrelativistic and relativistic regimes of the instability are considered.

  17. Nurse-Patient Communication Interactions in the Intensive Care Unit

    Science.gov (United States)

    Happ, Mary Beth; Garrett, Kathryn; Thomas, Dana DiVirgilio; Tate, Judith; George, Elisabeth; Houze, Martin; Radtke, Jill; Sereika, Susan

    2011-01-01

    Background The inability to speak during critical illness is a source of distress for patients, yet nurse-patient communication in the intensive care unit has not been systematically studied or measured. Objectives To describe communication interactions, methods, and assistive techniques between nurses and nonspeaking critically ill patients in the intensive care unit. Methods Descriptive observational study of the nonintervention/usual care cohort from a larger clinical trial of nurse-patient communication in a medical and a cardiothoracic surgical intensive care unit. Videorecorded interactions between 10 randomly selected nurses (5 per unit) and a convenience sample of 30 critically ill adults (15 per unit) who were awake, responsive, and unable to speak because of respiratory tract intubation were rated for frequency, success, quality, communication methods, and assistive communication techniques. Patients self-rated ease of communication. Results Nurses initiated most (86.2%) of the communication exchanges. Mean rate of completed communication exchange was 2.62 exchanges per minute. The most common positive nurse act was making eye contact with the patient. Although communication exchanges were generally (>70%) successful, more than one-third (37.7%) of communications about pain were unsuccessful. Patients rated 40% of the communication sessions with nurses as somewhat difficult to extremely difficult. Assistive communication strategies were uncommon, with little to no use of assistive communication materials (eg, writing supplies, alphabet or word boards). Conclusions Study results highlight specific areas for improvement in communication between nurses and nonspeaking patients in the intensive care unit, particularly in communication about pain and in the use of assistive communication strategies and communication materials. PMID:21362711

  18. Interaction of High Intensity Electromagnetic Waves with Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    G. Shvets

    2008-10-03

    The focus of our work during the duration of this grant was on the following areas: (a) the fundamental plasma physics of intense laser-plasma interactions, including the nonlinear excitation of plasma waves for accelerator applications, as well as the recently discovered by us phenomenon of the relativistic bi-stability of relativistic plasma waves driven by a laser beatwave; (b) interaction of high power microwave beams with magnetized plasma, including some of the recently discovered by us phenomena such as the Undulator Induced Transparency (UIT) as well as the new approaches to dynamic manipulation of microwave pulses; (c) investigations of the multi-color laser pulse interactions in the plasma, including the recently discovered by us phenomenon of Electromagnetic Cascading (EC) and the effect of the EC of three-dimensional dynamics of laser pulses (enhanced/suppressed selffocusing etc.); (d) interaction of high-current electron beams with the ambient plasma in the context of Fast Ignitor (FI) physics, with the emphasis on the nonlinear dynamics of the Weibel instability and beam filamentation.

  19. Ptychographic measurements of ultrahigh-intensity laser-plasma interactions

    Science.gov (United States)

    Leblanc, A.; Monchocé, S.; Bourassin-Bouchet, C.; Kahaly, S.; Quéré, F.

    2016-04-01

    The extreme intensities now delivered by femtosecond lasers make it possible to drive and control relativistic motion of charged particles with light, opening a path to compact particle accelerators and coherent X-ray sources. Accurately characterizing the dynamics of ultrahigh-intensity laser-plasma interactions as well as the resulting light and particle emissions is an essential step towards such achievements. This remains a considerable challenge, as the relevant scales typically range from picoseconds to attoseconds in time, and from micrometres to nanometres in space. In these experiments, owing to the extreme prevalent physical conditions, measurements can be performed only at macroscopic distances from the targets, yielding only partial information at these microscopic scales. This letter presents a major advance by applying the concepts of ptychography to such measurements, and thus retrieving microscopic information hardly accessible until now. This paves the way to a general approach for the metrology of extreme laser-plasma interactions on very small spatial and temporal scales.

  20. A Warm Fluid Model of Intense Laser-Plasma Interactions

    Science.gov (United States)

    Tarkenton, G. M.; Shadwick, B. A.; Esarey, E. H.; Leemans, W. P.

    2001-10-01

    Following up on our previous work on modeling intense laser-plasma interactions with cold fluids,(B.A.Shadwick, G. M. Tarkenton, E.H. Esarey, and W.P. Leemans, ``Fluid Modeling of Intense Laser-Plasma Interactions'', in Advanced Accelerator Concepts), P. Colestock and S. Kelley editors, AIP Conf. Proc. 569 (AIP, NY 2001), pg. 154. we are exploring warm fluid models. These models represent the next level in a hierarchy of complexity beyond the cold fluid approximation. With only a modest increase in computation effort, warm fluids incorporate effects that are relevant to a variety of technologically interesting cases. We present a derivation of the warm fluid from a kinetic (i.e. Vlasov) perspective and make a connection with the usual relativistic thermodynamic approach.(S. R. de Groot, W. A. van Leeuwen and Ch. G. van Weert, Relativistic Kinetic Theory: Principles and Applications), North-Holland (1980). We will provide examples where the warm fluids yield physics results not contained in the cold model and discuss experimental parameters where these effects are believed to be important.

  1. Relativistic electron mirrors from high intensity laser nanofoil interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, Daniel

    2012-12-21

    The reflection of a laser pulse from a mirror moving close to the speed of light could in principle create an X-ray pulse with unprecedented high brightness owing to the increase in photon energy and accompanying temporal compression by a factor of 4γ{sup 2}, where γ is the Lorentz factor of the mirror. While this scheme is theoretically intriguingly simple and was first discussed by A. Einstein more than a century ago, the generation of a relativistic structure which acts as a mirror is demanding in many different aspects. Recently, the interaction of a high intensity laser pulse with a nanometer thin foil has raised great interest as it promises the creation of a dense, attosecond short, relativistic electron bunch capable of forming a mirror structure that scatters counter-propagating light coherently and shifts its frequency to higher photon energies. However, so far, this novel concept has been discussed only in theoretical studies using highly idealized interaction parameters. This thesis investigates the generation of a relativistic electron mirror from a nanometer foil with current state-of-the-art high intensity laser pulses and demonstrates for the first time the reflection from those structures in an experiment. To achieve this result, the electron acceleration from high intensity laser nanometer foil interactions was studied in a series of experiments using three inherently different high power laser systems and free-standing foils as thin as 3nm. A drastic increase in the electron energies was observed when reducing the target thickness from the micrometer to the nanometer scale. Quasi-monoenergetic electron beams were measured for the first time from ultrathin (≤5nm) foils, reaching energies up to ∝35MeV. The acceleration process was studied in simulations well-adapted to the experiments, indicating the transition from plasma to free electron dynamics as the target thickness is reduced to the few nanometer range. The experience gained from those

  2. Generation of Energetic Particles in Intense Laser Matter Interaction

    Science.gov (United States)

    Ramakrishna, Bhuvanesh; Muhammad, Tayyab; Bagchi, Suman; Mandal, Tirtha; Chakera, Juzer; Naik, Prasad; Gupta, Parshotam Dass; Department of Physics, Indian Institute of Technology Hyderabad, India. Collaboration; Laser Plasma Division, Raja Ramanna CentreAdvanced Technology, Indore, India. Collaboration

    2016-10-01

    The acceleration of high energy ion beams up to several tens of MeV per nucleon following the interaction of an ultra-short (t 1018 W.cm-2. μm-2) laser pulse with solid targets, is one of the burgeoning fields of research in the last few years. Mechanisms leading to forward-accelerated, high quality ion beams, operating at currently accessible laser intensities (up to 1021 W/cm2) in laser-matter interactions, are mainly associated with large electric fields set up at the target rear interface by the laser-accelerated electrons leaving the target. In this paper, we present our recent experimental results on MeV ion generation by mildly relativistic (1019 W / cm - 2) short-pulse (45 fs) laser interaction with foil targets of varying thicknesses, structured / uniform targets (e.g. nano structures on thin metallic foils, sandwich targets). Spectral modification / bunching, and divergence from structured targets will be discussed. DST Ramanujan Fellowship (SR/S2/RJN-25/2012).

  3. Optimizing Interactive Development of Data-Intensive Applications

    Science.gov (United States)

    Interlandi, Matteo; Tetali, Sai Deep; Gulzar, Muhammad Ali; Noor, Joseph; Condie, Tyson; Kim, Miryung; Millstein, Todd

    2017-01-01

    Modern Data-Intensive Scalable Computing (DISC) systems are designed to process data through batch jobs that execute programs (e.g., queries) compiled from a high-level language. These programs are often developed interactively by posing ad-hoc queries over the base data until a desired result is generated. We observe that there can be significant overlap in the structure of these queries used to derive the final program. Yet, each successive execution of a slightly modified query is performed anew, which can significantly increase the development cycle. Vega is an Apache Spark framework that we have implemented for optimizing a series of similar Spark programs, likely originating from a development or exploratory data analysis session. Spark developers (e.g., data scientists) can leverage Vega to significantly reduce the amount of time it takes to re-execute a modified Spark program, reducing the overall time to market for their Big Data applications. PMID:28405637

  4. X-ray polarization spectroscopy from ultra-intense interactions

    Energy Technology Data Exchange (ETDEWEB)

    Booth, N; Pasley, J; Wagenaars, E; Waugh, J N; Woolsey, N C [Department of Physics, University of York, Heslington, York, YO10 5DD (United Kingdom); Clarke, R; Gallegos, P; Rajeev, P P [Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, OX11 0QN (United Kingdom); Gizzi, L; Koester, P; Labate, L; Levato, T [ILIL-IPCF, Consiglio Nazionale delle Ricerche, and INFN, Pisa (Italy); Gregori, G; Li, B [Department of Physics, University of Oxford, OX4 1PJ (United Kingdom); Makita, M; Riley, D, E-mail: nb505@york.ac.u [Department of Physics and Mathematics, Queens University Belfast, Belfast, BT1 4NN (United Kingdom)

    2010-08-01

    Detailed knowledge of fast electron energy transport following the interaction of ultrashort intense laser pulses is a key subject for fast ignition. This is a problem relevant to many areas of laser-plasma physics with particular importance to fast ignition and X-ray secondary source development, necessary for the development of large-scale facilities such as HiPER and ELI. Operating two orthogonal crystal spectrometers set at Bragg angles close to 45{sup 0} determines the X-ray s- and p- polarization ratio. From this ratio, it is possible to infer the velocity distribution function of the fast electron beam within the dense plasma. We report on results of polarization measurements at high density for sulphur and nickel buried layer targets in the high intensity range of 10{sup 19} - 10{sup 21} Wcm{sup -2}. We observe at 45{sup 0} the Ly-{alpha} doublet using two sets of orthogonal highly-orientated pyrolytic graphite (HOPG) crystals set in 1st order for sulphur and 3rd order for nickel.

  5. Hot Electron Diagnostic in a Solid Laser Target by Buried K-Shell Fluorer Technique from Ultra-Intense (3x1020W/cm2,< 500 J) Laser-Plasma Interactions on the Petawatt Laser at LLNL

    Energy Technology Data Exchange (ETDEWEB)

    Yasuike, K.; Key, M.H.; Hatchett, S.P.; Snavely, R.A.

    2000-06-29

    Characterization of hot electron production (a conversion efficiency from laser energy into electrons) in ultra intense laser-solid target interaction, using 1.06 {micro}m laser light with an intensity of up to 3 x 10{sup 20}W cm{sup -2} and an on target laser energy of {le}500 J, has been done by observing K{sub {beta}} as well as K{sub {alpha}} emissions from a buried Mo layer in the targets, which are same structure as in the previous 100 TW experiments but done under less laser intensity and energy conditions ({le} 4 x 10{sup 19} Wcm{sup -2} and {le} 30 J). The conversion efficiency from the laser energy into the energy, carried by hot electrons, has been estimated to be {approx}50%, which are little bit higher than the previous less laser energy ({approx} 20 J) experiments, yet the x-ray emission spectra from the target has change drastically, i.e., gamma flash.

  6. Progress in Ultrafast Intense Laser Science

    CERN Document Server

    Yamanouchi, Kaoru; Li, Ruxin; Chin, See Leang

    2009-01-01

    The PUILS series presents Progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science. PUILS has been stimulated by the recent development of ultrafast laser technologies. Each volume contains approximately 15 chapters, authored by researchers at the forefront. Each chapter opens with an overview of the topics to be discussed, so that researchers, who are not experts in the specific topics, as well as graduate students can grasp the importance and attractions of this sub-field of research, and these are followed by reports of cutting-edge discoveries. This fourth volume covers a broad range of topics from this interdisciplinary research field, focusing on strong field ionization of atoms; excitation, ionization and fragmentation of molecules; nonlinear intense optical phenomena and attosecond pulses; and laser - solid interactions and photoemission.

  7. Interactive Language Teaching in the Intensive English Classroom

    Institute of Scientific and Technical Information of China (English)

    TianAiguo

    2004-01-01

    In the traditional intensive English classroom, the teacher plays the dominant role; he is the lecturer who is interested in presenting language items, the organizer of teaching and learning activities, and the assessor of learners' performance.Students are usually bench-bound listeners. They watch the teacher explaining language points and giving samples, take

  8. Design Requirements for Communication-Intensive Interactive Applications

    Science.gov (United States)

    Bolchini, Davide; Garzotto, Franca; Paolini, Paolo

    Online interactive applications call for new requirements paradigms to capture the growing complexity of computer-mediated communication. Crafting successful interactive applications (such as websites and multimedia) involves modeling the requirements for the user experience, including those leading to content design, usable information architecture and interaction, in profound coordination with the communication goals of all stakeholders involved, ranging from persuasion to social engagement, to call for action. To face this grand challenge, we propose a methodology for modeling communication requirements and provide a set of operational conceptual tools to be used in complex projects with multiple stakeholders. Through examples from real-life projects and lessons-learned from direct experience, we draw on the concepts of brand, value, communication goals, information and persuasion requirements to systematically guide analysts to master the multifaceted connections of these elements as drivers to inform successful communication designs.

  9. Short-pulse high intensity laser thin foil interaction

    Science.gov (United States)

    Audebert, Patrick

    2003-10-01

    The technology of ultrashort pulse laser generation has progressed to the point that optical pulses larger than 10 J, 300 fs duration or shorter are routinely produced. Such pulses can be focused to intensities exceeding 10^18 W/cm^2. With high contrast pulses, these focused intensities can be used to heat solid matter to high temperatures with minimal hydrodynamic expansion, producing an extremely high energy-density state of matter for a short period of time. This high density, high temperature plasma can be studied by x-ray spectroscopy. We have performed experiments on thin foils of different elements under well controlled conditions at the 100 Terawatt laser at LULI to study the characteristics X-ray emission of laser heated solids. To suppress the ASE effect, the laser was frequency doubled. S-polarized light with a peak intensity of 10^19W/cm^2 was used to minimize resonance absorption. To decrease the effect of longitudinal temperature gradients very thin (800 μ) aluminum foil targets were used. We have also studied the effect of radial gradient by limiting the measured x-ray emission zone using 50μ or 100μ pinhole on target. The spectra, in the range 7-8Å, were recorded using a conical crystal spectrometer coupled to a 800 fs resolution streak camera. A Fourier Domain Interferometry (FDI) of the back of the foil was also performed providing a measurement of the hydrodynamic expansion as function of time for each shot. To simulate the experiment, we used the 1D hydrodynamic code FILM with a given set of plasma parameter (ρ, Te) as initial conditions. The X-ray emission was calculated by post processing hydrodynamic results with a collisional-radiative model which uses super-configuration average atomic data. The simulation reproduces the main features of the experimental time resolved spectrum.

  10. Large amplitude electromagnetic solitons in intense laser plasma interaction

    Institute of Scientific and Technical Information of China (English)

    Li Bai-Wen; Ishiguro S; Skoric M M

    2006-01-01

    This paper shows that the standing, backward- and forward-accelerated large amplitude relativistic electromagnetic solitons induced by intense laser pulse in long underdense collisionless homogeneous plasmas can be observed by particle simulations. In addition to the inhomogeneity of the plasma density, the acceleration of the solitons also depends upon not only the laser amplitude but also the plasma length. The electromagnetic frequency of the solitons is between about half and one of the unperturbed electron plasma frequency. The electrostatic field inside the soliton has a one-cycle structure in space, while the transverse electric and magnetic fields have half-cycle and one-cycle structure respectively.Analytical estimates for the existence of the solitons and their electromagnetic frequencies qualitatively coincide with our simulation results.

  11. On very short and intense laser-plasma interactions

    CERN Document Server

    Fiore, Gaetano

    2016-01-01

    We briefly report on some results regarding the impact of very short and intense laser pulses on a cold, low-density plasma initially at rest, and the consequent acceleration of plasma electrons to relativistic energies. Locally and for short times the pulse can be described by a transverse plane electromagnetic travelling-wave and the motion of the electrons by a purely Magneto-Fluido-Dynamical (MFD) model with a very simple dependence on the transverse electromagnetic potential, while the ions can be regarded as at rest; the Lorentz-Maxwell and continuity equations are reduced to the Hamilton equations of a Hamiltonian system with 1 degree of freedom, in the case of a plasma with constant initial density, or a collection of such systems otherwise. We can thus describe both the well-known "wakefield" behind the pulse and the recently predicted "slingshot effect", i.e. the backward expulsion of high energy electrons just after the laser pulse has hit the surface of the plasma.

  12. Particle acceleration by ultra-intense laser-plasma interactions

    CERN Document Server

    Nakajima, K

    2002-01-01

    The mechanism of particle acceleration by ultra-increase laser-plasma interaction is explained. Laser light can generate very high electric field by focusing with electromagnetic field matched phase with frequency. 1018 W/cm sup 2 laser light produce about 3 TV/m electric field. Many laser accelerators, which particle acceleration method satisfies phase matching particle and electric field, are proposed. In these accelerators, the Inverse Cherenkov Accelerator, Inverse FEL Accelerator and Laser-Plasma Accelerator are explained. Three laser-plasma acceleration mechanisms: Plasma Beat Wave Accelerator, Laser Wake-Field Accelerator (LWFA) and Self-Modulated LWFA, showed particle acceleration by experiments. By developing a high speed Z pinch capillary-plasma optical waveguide, 2.2 TW and 90 fs laser pulse could be propagated 2 cm at 40 mu m focusing radius in 1999. Dirac acceleration or ultra-relativistic ponderomotive acceleration mechanism can increase energy exponentially. (S.Y.)

  13. A Laboratory-Intensive Course on the Experimental Study of Protein-Protein Interactions

    Science.gov (United States)

    Witherow, D. Scott; Carson, Sue

    2011-01-01

    The study of protein-protein interactions is important to scientists in a wide range of disciplines. We present here the assessment of a lab-intensive course that teaches students techniques used to identify and further study protein-protein interactions. One of the unique elements of the course is that students perform a yeast two-hybrid screen…

  14. Electroweak interactions between intense neutrino beams and dense electron-positron magneto-plasmas

    CERN Document Server

    Tsintsadze, N L; Stenflo, L

    2003-01-01

    The electroweak coupling between intense neutrino beams and strongly degenerate relativistic dense electron-positron magneto-plasmas is considered. The intense neutrino bursts interact with the plasma due to the weak Fermi interaction force, and their dynamics is governed by a kinetic equation. Our objective here is to develop a kinetic equation for a degenerate neutrino gas and to use that equation to derive relativistic magnetohydrodynamic equations. The latter are useful for studying numerous collective processes when intense neutrino beams nonlinearly interact with degenerate, relativistic, dense electron-positron plasmas in strong magnetic fields. If the number densities of the plasma particles are of the order of 10 sup 3 sup 3 cm sup - sup 3 , the pair plasma becomes ultra-relativistic, which strongly affects the potential energy of the weak Fermi interaction. The new system of equations allows several neutrino-driven streaming instabilities involving new types of relativistic Alfven-like waves, The re...

  15. Potential drug-drug interactions in intensive care units of a hospital in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Oliveira-Paula

    2014-12-01

    Full Text Available Drug-drug interactions are important causes of adverse reactions in health units. The high consumption of medicines in intensive care units predisposes patients to potential drug-drug interactions. This study aimed at examining the frequency and the characteristics of drug-drug interactions in intensive care units of Hospital Universitario of Universidade Estadual de Londrina. We analyzed the prescriptions of patients over 18 years, admitted from January to May 2010, who remained hospitalized for at least four days. The analysis of drug-drug interactions was carried out using the Micromedex Drug-Reax® system. The interactions were classified by severity, time required for the onset of adverse effects, mechanism of action and quality of scientific evidence. Moreover, the possible adverse events were analyzed, as well as the recommended strategies of management and monitoring. Altogether, 198 different potential drug-drug interactions were identified with the occurrence of 1242 episodes. Of these, 43% were characterized by moderate interactions, 35% major, 16% minor and 6% contraindicated. The therapeutic inefficacy was the most frequent possible adverse event (18% and the main recommended strategy of management was the dose adjustment (35.6%. The most frequent interactions were: fentanyl + midazolam (8.6%, phenytoin + ranitidine (5.5% and midazolam + ranitidine (4.8%. These results demonstrate the importance of drug-drug interactions as a significant adverse event in intensive care units and thus, preventive measures are required to minimize this problem.

  16. Simulation of intense laser-dense matter interactions. X-ray production and laser absorption

    Energy Technology Data Exchange (ETDEWEB)

    Ueshima, Yutaka; Kishimoto, Yasuaki; Sasaki, Akira [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Sentoku, Yasuhiko; Tajima, Toshiki

    1998-03-01

    The development of short-pulse ultra high intensity lasers will enable us to generate short-pulse intense soft and hard X-rays. Acceleration of an electron in laser field generates intense illuminated located radiation, Larmor radiation, around KeV at 10{sup 18} W/cm{sup 2} with 100 TW and 1 {mu}m wave length laser. The Coulomb interaction between rest ions and relativistic electron generates broad energy radiation, bremsstrahlung emission, over MeV at 10{sup 18} W/cm{sup 2} with the same condition. These intense radiations come in short pulses of the same order as that of the irradiated laser. The generated intense X-rays, Larmor and bremsstrahlung radiation, can be applied to sources of short pulse X-ray, excitation source of inner-shell X-ray laser, position production and nuclear excitation, etc. (author)

  17. Impact of computer usage on the social interaction patterns of intense computer users and programmers

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, T.J.

    1986-01-01

    This research is a qualitative analysis of the impact of intense computer use upon interpersonal relations. Through the use of a structured interview conducted through an interactive computer program called SIGMUND, data were collected from sixty subjects on: (1) the areas of the computer's attraction; (2) the intensity of the interaction with the computer; (3) the level, breadth and depth of the intense computer users' interpersonal relations; and (4) the impact of computer usage on interpersonal relationships. Additional personal interviews were conducted by the researcher with seven of these subjects for further clarification. The subjects were all extensive computer users. All but one were computer programmers and spent a mean of 5.13 hours per day at the computer. Conclusions are that intense computer users (1) seek the same qualities in interpersonal relations that are found with the computer; (2) due to this, they gradually narrow their social field to include primarily other intense computer users; (3) seek instant intensity in interpersonal relations, often without success; and (4) become gradually isolated from humans as this failure increases, reverting more to computer use. Computer use need not, however, have this negative impact. With awareness of the problems and a concerted effort on the computer user's part, the intensity of the computer relationship can be carried over to interpersonal relationships with some benefit.

  18. Hot Electron Diagnostic in a Solid Laser Target by K-Shell Lines Measurement from Ultra-Intense Laser-Plasma Interactions R=1.06 (micron)m, 3x10 W/cm -2(less than or equal to) 500 J

    Energy Technology Data Exchange (ETDEWEB)

    Yasuike, K.; Wharton, K.B.; Key, M.; Hatchett, S.; Snavely, R.

    2000-07-27

    Characterization of hot electron production (a conversion efficiency from laser energy into electrons) from ultra intense laser-solid target interaction by observing molybdenum (Mo) K{beta} as well as K{alpha} emissions from a buried fluorescence tracer layer in the targets has been done. The experiments used 1.06 {micro}m laser light with an intensity of from 2 x 10{sup 18} up to 3 x 10{sup 20} W cm{sup -2} (20-0.5 ps pulse width) and an on target laser energy of 280-500 J. The conversion efficiency from the laser energy into the energy, carried by hot electrons, has been estimated to be {approx}50% for the 0.5 ps shots at an on-target laser intensity of 3 x 10{sup 20} W cm{sup -2}, which increased from {approx}30% at 1 x 10{sup 19} W cm{sup -2} 5 ps shots and {approx} 12% at 2 x 10{sup 18} W cm{sup -2} 20 ps shots.

  19. Effects of radiation damping in extreme ultra-intense laser-plasma interaction

    Science.gov (United States)

    Pandit, Rishi; Sentoku, Yasuhiko

    2011-10-01

    Effects of the radiation damping in the interaction of extremely intense laser (>1022 W/cm2) with overdense plasma are studied via a relativistic collisional particle-in-cell simulation, PICLS1D. We had derived the Landau-Lifshitz equation, which is the first order term of the Lorentz-Dirac equation, and also derived the second order term as the first time and implemented in the code. The code had been tested in a single particle motion at the extreme intensity laser. It was found that the first order damping term is reasonable up to the intensity 1022 W/cm2, but the second oder term becomes not negligible and comparable to the first order term beyond 1023 W/cm2. The radiation damping model was introduced to a one- dimensional particle-in-cell code (PIC), and tested in the laser - plasma interaction at extreme intensity. The strong damping of hot electrons in high energy tail was demonstrated in PIC simulations. Hot electrons generated by such extreme-intense laser lights on the plasma get the relativistic energy with gamma factor >100, and lose energy strongly by emitting radiation. The second order term becomes comparable to the first order term when the laser intensity >1023 W/cm2. US DOE DE-PS02-08ER08-16 and DE-FC02-04ER54789.

  20. Teaching Intensive Interaction to Paid Carers: Using the "Communities of Practice" Model to Inform Training

    Science.gov (United States)

    Rayner, Kelly; Bradley, Samantha; Johnson, Gemma; Mrozik, Jennifer H.; Appiah, Afua; Nagra, Maninder K.

    2016-01-01

    The engagement of people with learning disabilities in social communication is crucial to the development of relationships with others, a sense of social inclusion and self-worth. Intensive Interaction is an approach that can help carers develop their skills to engage people with severe and profound learning disabilities in personally relevant…

  1. Patterns of Non-Verbal Social Interactions within Intensive Mathematics Intervention Contexts

    Science.gov (United States)

    Thomas, Jonathan Norris; Harkness, Shelly Sheats

    2016-01-01

    This study examined the non-verbal patterns of interaction within an intensive mathematics intervention context. Specifically, the authors draw on social constructivist worldview to examine a teacher's use of gesture in this setting. The teacher conducted a series of longitudinal teaching experiments with a small number of young, school-age…

  2. PREFACE: XXX International Conference on Interaction of Intense Energy Fluxes with Matter

    Science.gov (United States)

    Fortov, V. E.; Khishchenko, K. V.; Karamurzov, B. S.; Efremov, V. P.; Sultanov, V. G.

    2015-11-01

    This paper is a preface to the proceedings of the XXX International Conference on Interaction of Intense Energy Fluxes with Matter, which was held in Elbrus settlement, in the Kabardino-Balkar Republic of the Russian Federation, from March 1-6, 2015.

  3. On the mechanisms of interaction of low-intensity millimeter waves with biological objects

    Energy Technology Data Exchange (ETDEWEB)

    Betskii, O.V.

    1994-07-01

    The interaction of low-intensity millimeter-band electromagnetic waves with biological objects is examined. These waves are widely used in medical practice as a means of physiotherapy for the treatment of various human disorders. Principal attention is given to the mechanisms through which millimeter waves act on the human organism.

  4. 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.

  5. Optimum laser intensity for the production of energetic deuterium ions from laser-cluster interaction

    CERN Document Server

    Bang, W; Quevedo, H J; Bernstein, A C; Gaul, E; Rougk, J; Aymond, F; Donovan, M; Ditmire, T

    2013-01-01

    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 mm^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 7.2x10^6 and 1.6x10^7 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.

  6. Electromagnetic cascade in high-energy electron, positron, and photon interactions with intense laser pulses

    Science.gov (United States)

    Bulanov, S. S.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2013-06-01

    The interaction of high-energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of photons. These photons can consequently convert into electron-positron pairs. As a result charged particles quickly lose their energy developing an exponentially decaying energy distribution, which suppresses the emission of high-energy photons, thus reducing the number of electron-positron pairs being generated. Therefore, this type of interaction suppresses the development of the electromagnetic avalanche-type discharge, i.e., the exponential growth of the number of electrons, positrons, and photons does not occur in the course of interaction. The suppression will occur when three-dimensional effects can be neglected in the transverse particle orbits, i.e., for sufficiently broad laser pulses with intensities that are not too extreme. The final distributions of electrons, positrons, and photons are calculated for the case of a high-energy e-beam interacting with a counterstreaming, short intense laser pulse. The energy loss of the e-beam, which requires a self-consistent quantum description, plays an important role in this process, as well as provides a clear experimental observable for the transition from the classical to quantum regime of interaction.

  7. Electromagnetic cascade in high energy electron, positron, and photon interactions with intense laser pulses

    CERN Document Server

    Bulanov, S S; Esarey, E; Leemans, W P

    2013-01-01

    The interaction of high energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of photons. These photons can consequently convert into electron-positron pairs. As a result charged particles quickly lose their energy developing an exponentially decaying energy distribution, which suppresses the emission of high energy photons, thus reducing the number of electron-positron pairs being generated. Therefore, this type of interaction suppresses the development of the electromagnetic avalanche-type discharge, i.e., the exponential growth of the number of electrons, positrons, and photons does not occur in the course of interaction. The suppression will occur when 3D effects can be neglected in the transverse particle orbits, i.e., for sufficiently broad laser pulses with intensities that are not too extreme. The final distributions of electrons, positrons, and...

  8. Application of norm-conserving pseudopotentials to intense laser-matter interactions

    Science.gov (United States)

    Tong, Xiao-Min; Wachter, Georg; Sato, Shunsuke A.; Lemell, Christoph; Yabana, Kazuhiro; Burgdörfer, Joachim

    2015-10-01

    We investigate the applicability of norm-conserving pseudopotentials to intense laser-matter interactions by performing time-dependent density functional theory simulations with an all-electron potential and with norm-conserving pseudopotentials. We find pseudopotentials to be reliable for the simulation of above-threshold ionization over a broad range of laser intensities both for the total ionization probability and the photoelectron energy spectrum. For the simulation of high-order-harmonic generation, pseudopotentials are shown to be applicable for lower-order harmonics in the spectral range in which the one-photon recombination dipole-matrix element can be recovered by the pseudopotential calculation.

  9. Drug-nutrient interactions in the intensive care unit: literature review and current recommendations

    Science.gov (United States)

    Heldt, Tatiane; Loss, Sergio Henrique

    2013-01-01

    Objective To describe the interactions between drugs and nutrients and their frequency in the intensive care unit and to assess the professional team's awareness regarding this subject. Methods The keywords "drug interactions" and "nutrition therapy" were searched in the PubMed (specifically MeSH) electronic database. The studies were systematically reviewed for descriptions of the types of interactions between drugs and nutrients, including their frequency and consequences. Results Sixty-seven articles were found. Among these, 20 articles were appropriate for the methodology adopted and accomplished the objectives of the study. Of these 20 articles, 14 articles described interactions between drugs and enteral nutrition, three described interactions between drugs and parenteral nutrition, and three described the importance and care required to avoid such interactions. Conclusions The literature about drug and nutrient interactions is limited and suggests the inability of health care teams to recognize the potential for these interactions. Possibly, the elaboration of a protocol to evaluate drug-nutrient interactions will increase the safety and efficacy of therapeutics. PMID:23917982

  10. The generation of high-quality, intense ion beams by ultra-intense lasers

    CERN Document Server

    Roth, M; Audebert, Patrick; Blazevic, A; Brambrink, E; Cowan, T E; Fuchs, J; Gauthier, J C; Geissel, M; Hegelich, M; Karsch, S; Meyer-Ter-Vehn, J; Ruhl, H; Schlegel, T; Stephens, R B

    2002-01-01

    Intense beams of protons and heavy ions have been observed in ultra-intense laser-solid interaction experiments. Thereby, a considerable fraction of the laser energy is transferred to collimated beams of energetic ions (e.g. up to 50 MeV protons; 100 MeV fluorine), which makes these beams highly interesting for various applications. Experimental results indicate a very short-pulse duration and an excellent beam quality, leading to beam intensities in the TW range. To characterize the beam quality and its dependence on laser parameters and target conditions we performed experiments using the 100 TW laser system at Laboratoire pour l'Utilisation des Lasers Intenses at the Ecole Polytechnique, France, with focused intensities exceeding 10 sup 1 sup 9 W cm sup - sup 2. We found a strong dependence on the target rear surface conditions allowing to tailor the ion beam by an appropriate target design. We also succeeded in the generation of heavy ion beams by suppressing the proton amount at the target surface. We wi...

  11. Understanding the Femtosecond Laser-Solid Interaction Near and Beyond the Material Damage Threshold

    Science.gov (United States)

    2016-05-23

    Presentation efforts: Journal articles: 1. Jian Cheng, Mingjun Chen, Kyle Kafka, Drake Austin, Jinghe Wang, Yong Xiao and Enam Chowdhury, Determination of...ultra-short laser induced damage threshold of KH2PO4 crystal: Numerical calculation and experimental verification, AIP Advances 6, 035221 (2016). 2...maximum file size for the Report Document is 50MB. Archival Publications (published) during reporting period: Journal Articles 1. Jian Cheng, Mingjun

  12. Classical Dynamics of Harmonic Generation of the Hydrogen Molecular Ion Interacting with Ultrashort Intense Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    LI Chao-Hong; DUAN Yi-Wu; Wing-Ki Liu; Jian-Min Yuan

    2001-01-01

    Within Born-Oppenheimer approximation, by using the classical trajectory theory, a description for the high order harmonic generation of the hydrogen molecular ion interacting with ultrashort laser pulses has been pre sented. The Coulomb singularities have been remedied by the regularization. The action-angle variables have been used to generate the initial inversion symmetry microcanonical distribution. Within a proper intensity range, a harmonic plateau with only odd harmonics appears. For a larger intensity, because of the existence of chaos, the harmonic spectra become noisier. For a large enough intensity, the ionization takes place and the harmonics disappear. So the chaos causes the noises, the ionization suppresses the harmonic generation, and the onset of the ionization follows the onset of chaos.

  13. Observing and estimating of intensive triad interaction occurrence in very shallow water

    Science.gov (United States)

    Mahmoudof, Seyed Masoud; Badiei, Peyman; Siadatmousavi, Seyed Mostafa; Chegini, Vahid

    2016-07-01

    In this study, a series of field measurements were carried out to investigate triad interactions of spectral peak in near shore. The water level fluctuations were recorded at 5 stations with depths varying from 0.8 to 5 m along a shore-perpendicular transect at sandy coasts of Nowshahr, located in the southern Caspian Sea coast. Two storms with significant wave height of approximately 1.4 m were observed during the measurement period. Using bispectral analysis, a new quantitative index is proposed to investigate temporal and spatial intensity of nonlinear interaction between spectral peak and other harmonics. The proposed index was evaluated for time series of water level data and compared with the bicoherence value of self-spectral peak triad interaction (SSPT); b2 (fp ,fp) . Comparing to SSPT, the proposed new index includes all positive and negative triad interactions with spectral peak. The relative depth, kp d , of non-breaking waves varied from 0.25 to 2.00 along the transect during the study period, where kp is the wave-number and d is the water depth. In general, SSPT increased by decreasing kp d ; however, the results showed that in two shallow stations the maximum SSPT did not correspond to the lowest values of kp d . A considerable time lag was observed between occurrence of the most intensive triad interactions and termination of wave breaking in post storm condition. Furthermore, the intensive triad interactions happened several hours after the largest Ursell numbers of non-breaking waves.

  14. Furry picture transition rates in the intense fields at a lepton collider interaction point

    Directory of Open Access Journals (Sweden)

    A. Hartin

    2015-04-01

    Full Text Available The effect on particle physics processes by intense electromagnetic fields in the charge bunch collisions at future lepton colliders is considered. Since the charge bunch fields are tied to massive sources (the e+e− charges, a reference frame is chosen in which the fields appear to be co-propagating. Solutions of the Dirac equation minimally coupled to the electromagnetic fields reasonably associated with two intense overlapping charge bunches are obtained and found to be a Volkov solution with respect to a null 4-vector whose 3-vector part lies in the common propagation direction. These solutions are used within the Furry interaction picture to calculate the beamstrahlung transition rate for electron radiation due to interaction with the electromagnetic fields of two colliding charge bunches. New analytic expressions are obtained and compared numerically with the beamstrahlung in the electromagnetic field of one charge bunch. The techniques developed will be applied to other collider physics processes in due course.

  15. Furry picture transition rates in the intense fields at a lepton collider interaction point

    CERN Document Server

    Hartin, Anthony

    2015-01-01

    The effect on particle physics processes by intense electromagnetic fields in the charge bunch collisions at future lepton colliders is considered. Since the charge bunch fields are tied to massive sources (the $e^{+}e^{-}$ charges), a reference frame is chosen in which the fields appear to be co-propagating. Solutions of the Dirac equation minimally coupled to the electromagnetic fields reasonably associated with two intense overlapping charge bunches are obtained and found to be a Volkov solution with respect to a null 4-vector whose 3-vector part lies in the common propagation direction. These solutions are used within the Furry interaction picture to calculate the beamstrahlung transition rate for electron radiation due to interaction with the electromagnetic fields of two colliding charge bunches. New analytic expressions are obtained and compared numerically with the beamstrahlung in the electromagnetic field of one charge bunch. The techniques developed will be applied to other collider physics process...

  16. Quasi-monoenergetic positron beam generation from ultra-intense laser-matter interactions

    Science.gov (United States)

    Nakamura, Tatsufumi; Hayakawa, Takehito

    2016-10-01

    In ultra-intense laser-matter interactions in which the radiation reaction effect plays an important role, γ-rays are effectively generated that are intense, collimated, and of short duration. These γ-rays propagate through the target, which results in the electron-positron pair creation caused by the interaction of the γ-rays with the nuclear electric fields. The positron beam thus generated has several unique features; it is quasi-monoenergetic in nature with a peak energy of hundreds of MeV, well collimated, and of ultra-short duration. Based on the numerical simulations, the dependences of the number and monochromaticity of the positrons on the laser and target parameters are explored, which leads to the proposal of a new type of the laser-driven positron source.

  17. Potential drug-drug interactions in cardiothoracic intensive care unit of a pulmonary teaching hospital.

    Science.gov (United States)

    Farzanegan, Behrooz; Alehashem, Maryam; Bastani, Marjan; Baniasadi, Shadi

    2015-02-01

    Little is known about clinically significant drug-drug interactions (DDIs) in respiratory settings. DDIs are more likely to occur in critically ill patients due to complex pharmacotherapy regimens and organ dysfunctions. The aim of this study was to identify the pattern of potential DDIs (pDDIs) occurring in cardiothoracic intensive care unit (ICU) of a pulmonary hospital. A prospective observational study was conducted for 6 months. All pDDIs for admitted patients in cardiothoracic ICU were identified with Lexi-Interact program and assessed by a clinical pharmacologist. The interacting drugs, reliability, mechanisms, potential outcomes, and clinical management were evaluated for severe and contraindicated interactions. The study included 195 patients. Lung cancer (14.9%) was the most common diagnosis followed by tracheal stenosis (14.3%). The rate of pDDIs was 720.5/100 patients. Interactions were more commonly observed in transplant patients. 17.7% of pDDIs were considered as severe and contraindicated interactions. Metabolism (54.8%) and additive (24.2%) interactions were the most frequent mechanisms leading to pDDIs, and azole antifungals and fluoroquinolones were the main drug classes involved. The pattern of pDDIs in cardiothoracic ICU differs from other ICU settings. Specialized epidemiological knowledge of drug interactions may help clinical practitioners to reduce the risk of adverse drug events.

  18. Study of hot electrons generated from intense laser-plasma interaction employing Image Plate

    Institute of Scientific and Technical Information of China (English)

    LIANG WenXi; JIN Zhan; WEI ZhiYi; ZHAO Wei; LI YingJun; ZHANG Jie; LI YuTong; XU MiaoHua; YUAN XiaoHui; ZHENG ZhiYuan; ZHANG Yi; LIU Feng; WANG ZhaoHua; LI HanMing

    2008-01-01

    Image Plate (IP) is convenient to be used and very suitable for radiation detection because of its advantages such as wide dynamic range, high detective quantum efficiency, ultrahigh sensitivity and superior linearity. The function mechanism and characteristics of IP are introduced in this paper. IP was employed in the study of hot electrons generated from intense laser-plasma interaction. The angular distri-bution and energy spectrum of hot electrons were measured with IP in the experi-ments. The results demonstrate that IP is an effective radiation detector for the study of laser-plasma interaction.

  19. Study of hot electrons generated from intense laser-plasma interaction employing Image Plate

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Image Plate (IP) is convenient to be used and very suitable for radiation detection because of its advantages such as wide dynamic range, high detective quantum efficiency, ultrahigh sensitivity and superior linearity. The function mechanism and characteristics of IP are introduced in this paper. IP was employed in the study of hot electrons generated from intense laser-plasma interaction. The angular distri- bution and energy spectrum of hot electrons were measured with IP in the experi- ments. The results demonstrate that IP is an effective radiation detector for the study of laser-plasma interaction.

  20. Electromagnetic Confined Plasma Target for Interaction Studies with Intense Laser Fields

    Energy Technology Data Exchange (ETDEWEB)

    Zielbauer, B; Ursescu, U; Trotsenko, S; Spillmann, U; Schuch, R; Stohlker, T; Kuhl, T; Borneis, S; Schenkel, T; McDonald, J; Schneider, D

    2006-08-09

    The paper describes a novel application of an electron beam ion trap as a plasma target facility for intense laser-plasma interaction studies. The low density plasma target ({approx}10{sup 13}/cm{sup 3}) is confined in a mobile cryogenic electromagnetic charged particle trap, with the magnetic confinement field of 1-3T maintained by a superconducting magnet. Ion plasmas for a large variety of ion species and charge states are produced and maintained within the magnetic field and the space charge of an energetic electron beam in the ''Electron Beam Ion Trap'' (EBIT) geometry. Intense laser beams (optical lasers, x-ray lasers and upcoming ''X-Ray Free Electron Lasers'' (XFEL)) provide strong time varying electromagnetic fields (>10{sup 12} V/cm in femto- to nano-sec pulses) for interactions with electromagnetically confined neutral/non-neutral plasmas. The experiments are aimed to gain understanding of the effects of intense photon fields on ionization/excitation processes, the ionization balance, as well as photon polarization effects. First experimental scenarios and tests with an intense laser that utilize the ion plasma target are outlined.

  1. Radiation reaction effects on the interaction of an electron with an intense laser pulse.

    Science.gov (United States)

    Kravets, Yevgen; Noble, Adam; Jaroszynski, Dino

    2013-07-01

    Radiation reaction effects will play an important role in near-future laser facilities, yet their theoretical description remains obscure. We explore the Ford-O'Connell equation for radiation reaction, and discuss its relation to other commonly used treatments. By analyzing the interaction of a high energy electron in an intense laser pulse, we find that radiation reaction effects prevent the particle from accessing a regime in which the Landau-Lifshitz approximation breaks down.

  2. Nutrition Education Research Brief: Message Framing, Use of Interactive Technology to Tailor Messages, and Intervention Intensity

    OpenAIRE

    Mary Kay Fox; Charlotte Hanson; Ronette Briefel

    2007-01-01

    This research brief is intended to assist nutrition educators in assessing whether specific characteristics of nutrition messages promote desired dietary behavior changes. Based on a computerized literature search targeting peer-reviewed journal articles, it highlights three topics pertinent to the design of nutrition education programs—message framing, use of interactive technology to tailor messages, and intervention intensity. While some promising results were found to be associated with...

  3. Intense Cherenkov-type terahertz electromagnetic radiation from ultrafast laser-plasma interaction

    Institute of Scientific and Technical Information of China (English)

    Hu Qiang-Lin; Liu Shi-Bing; Li Wei

    2008-01-01

    A Cherenkov-type terahertz electromagnetic radiation is revealed, which results efficiently from the collective effects in the time-domain of ultrafast pulsed electron current produced by ultrafast intense laser-plasma interaction.The emitted pulse waveform and spectrum, and the dependence of laser pulse parameters on the structure of the radiation field are investigated numerically. The condition of THz radiation generation in this regime and Cherenkov geometry of the radiation field are studied analytically.

  4. Patterns of non-verbal social interactions within intensive mathematics intervention contexts

    Science.gov (United States)

    Thomas, Jonathan Norris; Harkness, Shelly Sheats

    2016-06-01

    This study examined the non-verbal patterns of interaction within an intensive mathematics intervention context. Specifically, the authors draw on social constructivist worldview to examine a teacher's use of gesture in this setting. The teacher conducted a series of longitudinal teaching experiments with a small number of young, school-age children in the context of early arithmetic development. From these experiments, the authors gathered extensive video records of teaching practice and, from an inductive analysis of these records, identified three distinct patterns of teacher gesture: behavior eliciting, behavior suggesting, and behavior replicating. Awareness of their potential to influence students via gesture may prompt teachers to more closely attend to their own interactions with mathematical tools and take these teacher interactions into consideration when forming interpretations of students' cognition.

  5. Network of Spaces and Interaction-Related Behaviors in Adult Intensive Care Units

    Directory of Open Access Journals (Sweden)

    Mahbub Rashid

    2014-12-01

    Full Text Available Using three spatial network measures of “space syntax”, this correlational study describes four interaction-related behaviors among three groups of users in relation to visibility and accessibility of spaces in four adult intensive care units (ICUs of different size, geometry, and specialty. Systematic field observations of interaction-related behaviors show significant differences in spatial distribution of interaction-related behaviors in the ICUs. Despite differences in unit characteristics and interaction-related behaviors, the study finds that when nurses and physicians “interact while sitting” they prefer spaces that help maintain a high level of environmental awareness; that when nurses “walk” and “interact while walking” they avoid spaces with better global access and visibility; and that everyone in ICUs “walk” more in spaces with higher control over neighboring spaces. It is argued that such consistent behavioral patterns occur due to the structural similarities of spatial networks over and above the more general functional similarities of ICUs.

  6. Radiation from high-intensity ultrashort-laser-pulse and gas-jet magnetized plasma interaction.

    Science.gov (United States)

    Dorranian, Davoud; Starodubtsev, Mikhail; Kawakami, Hiromichi; Ito, Hiroaki; Yugami, Noboru; Nishida, Yasushi

    2003-08-01

    Using a gas-jet flow, via the interaction between an ultrashort high-intensity laser pulse and plasma in the presence of a perpendicular external dc magnetic field, the short pulse radiation from a magnetized plasma wakefield has been observed. Different nozzles are used in order to generate different densities and gas profiles. The neutral density of the gas-jet flow measured with a Mach-Zehnder interferometer is found to be proportional to back pressure of the gas jet in the range of 1 to 8 atm. Strength of the applied dc magnetic field varies from 0 to 8 kG at the interaction region. The frequency of the emitted radiation with the pulse width of 200 ps (detection limit) is in the millimeter wave range. Polarization and spatial distributions of the experimental data are measured to be in good agreement with the theory based on the V(p)xB radiation scheme, where V(p) is the phase velocity of the electron plasma wave and B is the steady magnetic field intensity. Characteristics of the radiation are extensively studied as a function of plasma density and magnetic field strength. These experiments should contribute to the development of a new kind of millimeter wavelength radiation source that is tunable in frequency, pulse duration, and intensity.

  7. Interaction of intense femtosecond laser pulses with high-Z solids

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, A.; Sasaki, Akira; Utsumi, Takayuki; Fukumoto, Ichirou; Tajima, Toshiki [Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Institute, Neyagawa, Osaka (Japan); Yoshida, Masatake [National Institute of Material and Chemical Research, Tsukuba, Ibaraki (Japan); Kondo, Kenichi [Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama, Kanagawa (Japan)

    2000-03-01

    A plasma irradiated by an intense very short pulse laser can be an ultimate high brightness source of incoherent inner-shell X-ray emission of 1-30 keV. The recently developed 100 TW, 20 fs laser facility in JAERI can make considerable enhancement here. To show this a hybrid model combining hydrodynamics and collisional particle-in-cell simulations is applied. Effect of laser prepulse on the interaction of an intense s-polarized femtosecond, {approx}20/40 fs, laser pulse with high-Z solid targets is studied. A new absorption mechanism originating from the interaction of the laser pulse with plasma waves excited by the relativistic component of the Lorentz force is found to increase the absorption rate over 30% even for a very short laser pulse. The obtained hot electron temperature exceeds 0.5-1 MeV at optimal conditions for absorption. Results of the simulation for lower laser pulse intensities are in good agreement with the experimental measurements of the hot electron energy distribution. (author)

  8. Intra-pulse transition between ion acceleration mechanisms in intense laser-foil interactions

    Energy Technology Data Exchange (ETDEWEB)

    Padda, H.; King, M.; Gray, R. J.; Powell, H. W.; Gonzalez-Izquierdo, B.; Wilson, R.; Dance, R. J.; MacLellan, D. A.; Butler, N. M. H.; Capdessus, R.; McKenna, P., E-mail: paul.mckenna@strath.ac.uk [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Stockhausen, L. C. [Centro de Laseres Pulsados (CLPU), Parque Cientifico, Calle del Adaja s/n. 37185 Villamayor, Salamanca (Spain); Carroll, D. C. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom); Yuan, X. H. [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China); Borghesi, M. [Centre for Plasma Physics, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Neely, D. [SUPA Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Central Laser Facility, STFC Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom)

    2016-06-15

    Multiple ion acceleration mechanisms can occur when an ultrathin foil is irradiated with an intense laser pulse, with the dominant mechanism changing over the course of the interaction. Measurement of the spatial-intensity distribution of the beam of energetic protons is used to investigate the transition from radiation pressure acceleration to transparency-driven processes. It is shown numerically that radiation pressure drives an increased expansion of the target ions within the spatial extent of the laser focal spot, which induces a radial deflection of relatively low energy sheath-accelerated protons to form an annular distribution. Through variation of the target foil thickness, the opening angle of the ring is shown to be correlated to the point in time transparency occurs during the interaction and is maximized when it occurs at the peak of the laser intensity profile. Corresponding experimental measurements of the ring size variation with target thickness exhibit the same trends and provide insight into the intra-pulse laser-plasma evolution.

  9. Comparing Particle-in-Cell QED Models for High-Intensity Laser-Plasma Interactions

    Science.gov (United States)

    Luedtke, Scott V.; Labun, Lance A.; Hegelich, Björn Manuel

    2016-10-01

    High-intensity lasers, such as the Texas Petawatt, are pushing into new regimes of laser-matter interaction, requiring continuing improvement and inclusion of new physics effects in computer simulations. Experiments at the Texas Petawatt are reaching intensity regimes where new physics-quantum electrodynamics (QED) corrections to otherwise classical plasma dynamics-becomes important. We have two particle-in-cell (PIC) codes with different QED implementations. We review the theory of photon emission in QED-strong fields, and cover the differing PIC implementations. We show predictions from the two codes and compare with ongoing experiments. This work was supported by NNSA cooperative agreement DE-NA0002008, the Defense Advanced Research Projects Agency's PULSE program (12-63-PULSE-FP014) and the Air Force Office of Scientific Research (FA9550-14-1-0045). HPC resources provided by TACC.

  10. Intra-pulse transition between ion acceleration mechanisms in intense laser-foil interactions

    Science.gov (United States)

    Padda, Hersimerjit; King, Martin; Gray, Ross; Powell, Haydn; Gonzalez-Izquierdo, Bruno; Stockhausen, Luca; Wilson, Robbie; Carroll, David; Dance, Rachel; MacLellan, David; Yuan, Xiaohui; Butler, Nick; Capdessus, Remi; Borghesi, Marco; Neely, David; McKenna, Paul

    2016-10-01

    Laser-driven sheath acceleration of ions has been widely studied and the recent move to ultra thin foil interactions enables promising new acceleration mechanisms. However, the acceleration dynamics in this regime are complex and over the course of the laser-foil interaction multiple ion acceleration mechanisms can occur, resulting in the dominant mechanism changing throughout the interaction. Measuring the spatial intensity distribution of the accelerated proton beam we investigate the transition from radiation pressure acceleration to transparency-driven processes. Using PIC simulations, the radiation pressure drives an increased expansion of the target ions, which results in a radial deflection of low MeV protons to form an annular distribution. By varying the thickness of the target, the opening angle of the ring is shown to be correlated to the point in time that transparency occurs and is maximised at the peak of the laser intensity profile. Measurements of the ring size as a function of target thickness are found to be in good agreement with the simulation results.

  11. Using XFELs for Probing of Complex Interaction Dynamics of Ultra-Intense Lasers with Solid Matter

    CERN Document Server

    Kluge, Thomas; Huang, Lingen; Metzkes, Josefine; Schramm, Ulrich; Bussmann, Michael; Cowan, Thomas E

    2013-01-01

    We demonstrate the potential of X-ray free-electron lasers (XFEL) to advancethe understanding of complex plasma dynamics by allowing for the first time nanometer and femtosecond resolution at the same time in plasma diagnostics. Plasma phenomena on such short timescales are of high relevance for many fields of physics, in particular in the ultra-intense ultra-short laser interaction with matter. Highly relevant yet only partially understood phenomena may become directly accessible in experiment. These include relativistic laser absorption at solid targets, creation of energetic electrons and electron transport in warm dense matter, including the seeding and development of surface and beam instabilities, ambipolar expansion, shock formation, and dynamics at the surfaces or at buried layers. We demonstrate the potentials of XFEL plasma probing for high power laser matter interactions using exemplary the small angle X-ray scattering technique, focusing on general considerations for XFEL probing.

  12. Ultra-intense laser-plasma interaction toward Weibel-mediated collisionless shocks formation

    Science.gov (United States)

    Grassi, Anna; Grech, M.; Amiranoff, F.; Macchi, A.; Riconda, C.

    2016-10-01

    The rapid developments in laser technology will soon offer the opportunity to study in the laboratory the processes driving Weibel-mediated collisionless shocks, typical of various astrophysical scenarii. The interaction of an ultra-intense laser with an overdense plasma has been identified as the preferential configuration. Yet, the experimental requirements still need to be properly investigated. High performance computing simulations are a necessary tool for this study. In this work, we present a series of kinetic simulations performed with the PIC code SMILEI, varying the laser and plasma parameters. In particular, we will study the effect of the laser polarisation and plasma density to obtain the best conditions for the creation of a collisionless shock. The role of the electrons heated at the interaction surface and of particles accelerated via the Hole Boring (laser-piston) mechanism on the generation of the current filamentation instability and the subsequent shock front formation will be highlighted.

  13. Clinical relevancy and risks of potential drug–drug interactions in intensive therapy

    Science.gov (United States)

    Rodrigues, Aline Teotonio; Stahlschmidt, Rebeca; Granja, Silvia; Falcão, Antonio Luis Eiras; Moriel, Patricia; Mazzola, Priscila Gava

    2014-01-01

    Purpose Evaluate the potential Drug–Drug Interactions (pDDI) found in prescription orders of adult Intensive Care Unit (ICU) of a Brazilian public health system hospital; quantify and qualify the pDDI regarding their severity and risks to the critical patient, using the database from Micromedex®. Methods Prospective study (January–December of 2011) collecting and evaluating 369 prescription orders (convenient sampling), one per patient. Results During the study 1844 pDDIs were identified and distributed in 405 pairs (medication A × medication B combination). There was an average of 5.00 ± 5.06 pDDIs per prescription order, the most prevalent being moderate and important interactions, present in 74% and 67% of prescription orders, respectively. In total, there were 9 contraindicated, 129 important and 204 moderate pDDIs. Among them 52 had as management recommendation to “avoid concomitant use” or “suspension of medication”, while 306 had as recommendation “continuous and adequate monitoring”. Conclusion The high number of pDDIs found in the study combined with the evaluation of the clinical relevancy of the most frequent pDDIs in the ICU shows that moderate and important interactions are highly incident. As the majority of them demand monitoring and adequate management, being aware of these interactions is major information for the safe and individualized risk management. PMID:27134536

  14. Lambda-Lambda interaction from two-particle intensity correlation in relativistic heavy-ion collisions

    CERN Document Server

    Ohnishi, Akira; Furumoto, Takenori

    2015-01-01

    We investigate $\\Lambda\\Lambda$ interaction dependence of the $\\Lambda\\Lambda$ intensity correlation in high-energy heavy-ion collisions. By analyzing the correlation data recently obtained by the STAR collaboration based on theoretically proposed $\\Lambda\\Lambda$ interactions, we give a constraint on the $\\Lambda\\Lambda$ scattering length, $-1.25~\\text{fm} < a_0 < 0$, suggesting that $\\Lambda\\Lambda$ interaction is weakly attractive and there is no loosely bound state. In addition to the fermionic quantum statistics and the $\\Lambda\\Lambda$ interaction, effects of collective flow, feed-down from $\\Sigma^0$, and the residual source are also found to be important to understand the data. We demonstrate that the correlation data favor negative $\\Lambda\\Lambda$ scattering length with the pair purity parameter $\\lambda=(0.67)^2$ evaluated by using experimental data on the $\\Sigma^0/\\Lambda$ ratio, while the positive scattering length could be favored when we regard $\\lambda$ as a free fitting parameter.

  15. The unsteady regime of intense short-pulse under-dens plasma interactions

    CERN Document Server

    Yazdanpanah, Jam; Chakhmachi, Amir; Khalilzadeh, Elnaz

    2015-01-01

    We have performed a detailed study on the interaction of ultra-intense, short laser pulse with under-dens plasma. The underlying interaction physics is outlined and key topics like laser absorption and electron acceleration are addressed. This study is assisted by the extensive 1D3V particle-in-cell (PIC) simulations over a wide range of initial plasma densities, , ( is the critical density) and laser intensities, . It is noticed that the steady propagation of a short-pulse through a low density plasma is violated in proportion to the expression ( and are electron density laser gamma factor). Accordingly, when the plasma density rises toward the critical value, a new physical regime appears which has not been adequately explored, previously. Using general conservation laws it is demonstrated that due to the radiation pressure, strong wave-breaking (phase mixing) occurs in this regime. The electron acceleration is described in terms of the wave-breaking followed by the direct laser acceleration (DLA). A new ph...

  16. Situational Motivation and Perceived Intensity: Their Interaction in Predicting Changes in Positive Affect from Physical Activity

    Directory of Open Access Journals (Sweden)

    Eva Guérin

    2012-01-01

    Full Text Available There is evidence that affective experiences surrounding physical activity can contribute to the proper self-regulation of an active lifestyle. Motivation toward physical activity, as portrayed by self-determination theory, has been linked to positive affect, as has the intensity of physical activity, especially of a preferred nature. The purpose of this experimental study was to examine the interaction between situational motivation and intensity [i.e., ratings of perceived exertion (RPE] in predicting changes in positive affect following an acute bout of preferred physical activity, namely, running. Fourty-one female runners engaged in a 30-minute self-paced treadmill run in a laboratory context. Situational motivation for running, pre- and post-running positive affect, and RPE were assessed via validated self-report questionnaires. Hierarchical regression analyses revealed a significant interaction effect between RPE and introjection (P<.05 but not between RPE and identified regulation or intrinsic motivation. At low levels of introjection, the influence of RPE on the change in positive affect was considerable, with higher RPE ratings being associated with greater increases in positive affect. The implications of the findings in light of SDT principles as well as the potential contingencies between the regulations and RPE in predicting positive affect among women are discussed.

  17. Ultra Intense Laser Pulse Interactions with Planer and Spherical Plasmas for Fast Ignitor

    Science.gov (United States)

    Tanaka, Kazuo A.

    1999-11-01

    The fast ignitor concept requires the guiding or penetration of an ultra-intense laser close to a highly compressed (1000 times solid density) core and the generation of energetic electrons (MeV). Ultra-intense laser plasma interactions have been intensively studied using the Peta Watt Module (PWM) laser system synchronized with the GEKKO XII laser system. The ultra-intense laser pulse of 50J energy, 0.5-1 psec pulse width and 1053 nm laser wavelength could be focused onto a preformed plasma created on a solid target at an intensity of 1e19 W/cm2. The preformed plasma had a cut-off density surface at around 100 micron from the surface. Changing the focus position of this 100 TW laser pulse relative to the preformed plasma, we found an anomalous mode. Side view of x-ray pinhole camera showed that there was a local tiny spot almost at the surface of the solid target which indicates the propagation of the pulse in the long scale-length plasma into an over-dense region for over 100 micorn distance. The erergy spectrum and angular distribution of more than MeV electrons were measured. Its energy transport was studied with K-a spectroscopy. The backscattered light of the ultra-intense laser light was spectrally and spatially resolved. The backscattered light image showed several hot spots within the focused region. The spatilally resolved spectra of the backscattered light were totally different at the hot spots and surrounding regions. The details of neutron spectra were measured using ``MANDALA" neutron spectormeters with a total of 841 channel photo-multiplier detectors. The data indicates that deuterium ions were accelerated by the hot electrons up to 100 keV and created beam fusion reactions within solid CD targets. Guiding channels were created utilizing a ponderomotive self-focusing in preformed plasmas created on a solid target. The self-focus channel was measured by both UV and x-ray laser probes. The details of the experiment as well as the theoretical

  18. Nonlinear interactions between electromagnetic waves and electron plasma oscillations in quantum plasmas.

    Science.gov (United States)

    Shukla, P K; Eliasson, B

    2007-08-31

    We consider nonlinear interactions between intense circularly polarized electromagnetic (CPEM) waves and electron plasma oscillations (EPOs) in a dense quantum plasma, taking into account the electron density response in the presence of the relativistic ponderomotive force and mass increase in the CPEM wave fields. The dynamics of the CPEM waves and EPOs is governed by the two coupled nonlinear Schrödinger equations and Poisson's equation. The nonlinear equations admit the modulational instability of an intense CPEM pump wave against EPOs, leading to the formation and trapping of localized CPEM wave pipes in the electron density hole that is associated with a positive potential distribution in our dense plasma. The relevance of our investigation to the next generation intense laser-solid density plasma interaction experiments is discussed.

  19. Structured plasma waveguides and deep EUV generation enabled by intense laser-cluster interactions

    Science.gov (United States)

    Layer, Brian David

    Using the unique properties of the interaction between intense, short-pulse lasers and nanometer scale van-der-Waals bonded aggregates (or 'clusters'), modulated waveguides in hydrogen, argon and nitrogen plasmas were produced and extreme ultraviolet (EUV) light was generated in deeply ionized nitrogen plasmas. A jet of clusters behaves as an array of mass-limited, solid-density targets with the average density of a gas. Two highly versatile experimental techniques are demonstrated for making preformed plasma waveguides with periodic structure within a laser-ionized cluster jet. The propagation of ultra-intense femtosecond laser pulses with intensities up to 2 x1017 W/cm2 has been experimentally demonstrated in waveguides generated using both methods, limited by available laser energy. The first uses a 'ring grating' to impose radial intensity modulations on the channel-generating laser pulse, which leads to axial intensity modulations at the laser focus within the cluster jet target. This creates a waveguide with axial modulations in diameter with a period between 35 mum and 2 mm, determined by the choice of ring grating. The second method creates modulated waveguides by focusing a uniform laser pulse within a jet of clusters with ow that has been modulated by periodically spaced wire obstructions. These wires make sharp, stable voids as short as 50 mum with a period as small as 200 mum within waveguides of hydrogen, nitrogen, and argon plasma. The gaps persist as the plasma expands for the full lifetime of the waveguide. This technique is useful for quasi-phase matching applications where index-modulated guides are superior to diameter modulated guides. Simulations show that these 'slow wave' guiding structures could allow direct laser acceleration of electrons, achieving gradients of 80 MV/cm and 10 MV/cm for laser pulse powers of 1.9 TW and 30 GW, respectively. Results are also presented from experiments in which a nitrogen cluster jet from a cryogenically

  20. Rewriting the rules governing high intensity interactions of light with matter

    Science.gov (United States)

    Borisov, Alex B.; McCorkindale, John C.; Poopalasingam, Sankar; Longworth, James W.; Simon, Peter; Szatmári, Sándor; Rhodes, Charles K.

    2016-04-01

    The trajectory of discovery associated with the study of high-intensity nonlinear radiative interactions with matter and corresponding nonlinear modes of electromagnetic propagation through material that have been conducted over the last 50 years can be presented as a landscape in the intensity/quantum energy [I-ħω] plane. Based on an extensive series of experimental and theoretical findings, a universal zone of anomalous enhanced electromagnetic coupling, designated as the fundamental nonlinear domain, can be defined. Since the lower boundaries of this region for all atomic matter correspond to ħω ~ 103 eV and I  ≈  1016 W cm-2, it heralds a future dominated by x-ray and γ-ray studies of all phases of matter including nuclear states. The augmented strength of the interaction with materials can be generally expressed as an increase in the basic electromagnetic coupling constant in which the fine structure constant α  →  Z 2 α, where Z denotes the number of electrons participating in an ordered response to the driving field. Since radiative conditions strongly favoring the development of this enhanced electromagnetic coupling are readily produced in self-trapped plasma channels, the processes associated with the generation of nonlinear interactions with materials stand in natural alliance with the nonlinear mechanisms that induce confined propagation. An experimental example involving the Xe (4d105s25p6) supershell for which Z  ≅  18 that falls in the specified anomalous nonlinear domain is described. This yields an effective coupling constant of Z 2 α  ≅  2.4  >  1, a magnitude comparable to the strong interaction and a value rendering as useless conventional perturbative analyses founded on an expansion in powers of α. This enhancement can be quantitatively understood as a direct consequence of the dominant role played by coherently driven multiply-excited states in the dynamics of the coupling. It is also

  1. Picosecond Neutron Yields from Ultra-Intense Laser-Target Interactions

    Science.gov (United States)

    Ellison, C. Leland; Fuchs, Julien

    2009-11-01

    High-flux neutron sources for neutron imaging and materials analysis applications have typically been provided by accelerator-based (Spallation Neutron Source) and reactor-based (High Flux Isotope Reactor) neutron sources. A novel approach is to use ultra-intense (> 10^18 W/cm^2) laser-target interactions to generate picosecond, collimated neutrons. Here we examine the feasibility of a source based on current (LULI) and upcoming laser facility capabilities. A Monte-Carlo code calculates angular and energy distributions of neutrons generated by D-D fusion events occurring within a deuterated target for a given incident beam of D+ ions. The parameters of the deuteron beam are well understood from laser-plasma and laser-target studies relevant to fast-ignition fusion. Expected neutron yields are presented in comparison to conventional neutron sources, previous experimental neutron yields, and within the context of neutron shielding safety requirements.

  2. Production and dynamics of positrons in ultrahigh intensity laser-foil interactions

    CERN Document Server

    Kostyukov, I Yu

    2016-01-01

    The electron-positron pair production accompanying interaction of a circularly polarized laser pulse with a foil is studied for laser intensities higher than $10^{24}$W cm$^{-2}$. The laser energy penetrates into the foil due to the effect of the relativistic hole-boring. It is demonstrated that the electron-positron plasma is produced as a result of quantum-electrodynamical cascading in the field of the incident and reflected laser light in front of the foil. The incident and reflected laser light makes up the circularly polarized standing wave in the reference frame of the hole-boring front and the pair density peaks near the nodes and antinodes of the wave. A model based on the particle dynamics with radiation reaction effect near the magnetic nodes is developed. The model predictions are verified by 3D PIC-MC simulations.

  3. Prepulse effects on the interaction of intense femtosecond laser pulses with high-Z solids

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, Alexei; Sasaki, Akira; Utsumi, Takayuki; Fukumoto, Ichirou; Tajima, Toshiki; Saito, Fumikazu; Hironaka, Yoichiro; Nakamura, Kazutaka G.; Kondo, Ken-ichi; Yoshida, Masatake

    2000-11-01

    K{alpha} emission of high-Z solid targets irradiated by an intense, short (<100 fs) laser pulse in the 10 keV region is shown to be sensitive to the electron energy cutoff, which is strongly dependent on the density gradient of the plasma corona formed by a long prepulse. The absorption rate of short laser pulses, the hot electron distribution, and x-ray emission from a Cu slab target are studied via a hybrid model, which combines the hydrodynamics, collisional particle-in-cell, and Monte Carlo simulation techniques, and via a direct spectroscopic measurement. An absorption mechanism originating from the interaction of the laser pulse with plasma waves is found to increase the absorption rate by over 30% even for a very short, s-polarized laser pulse. Calculated and measured x-ray spectra are in good agreement, confirming the electron energy cutoff.

  4. Lighting up the Christmas tree: high-intensity laser interactions with a nano-structured target

    CERN Document Server

    Gonoskov, A; Ilderton, A; Mackenroth, F; Marklund, M

    2014-01-01

    We perform a numerical study of the interaction of a high-intensity laser pulse with a nano-structured target. In particular, we study a target where the nano-structuring increases the absorption rate as compared to the flat target case. The transport of electrons within the target, and in particular in the nano-structure, is analysed. It is shown that it is indeed possible, using a terawatt class laser, to light up a nano-scale Christmas tree. Due to the form of the tree we achieve very strong edge fields, in particular at the top where the star is located. Such edge fields, as here located at ion rich spots, makes strong acceleration gradients possible. It also results in a nice, warm glow suitable for the holiday season.

  5. Collisional and collision-less surface heating in intense laser matter interaction

    Science.gov (United States)

    Kemp, Andreas; Divol, Laurent

    2015-11-01

    We explore the interaction of high-contrast intense sub-100 fs laser pulses with solid density tar- gets, using numerically converged collisional particle-in-cell simulations in one two and three dimen- sions. We observe a competition between two mechanisms that can lead to plasma heating. Inverse bremsstrahlung at solid density on one hand, and electrons scattering off plasma waves on the other, can both heat the skin layer to keV temperatures on a femtosecond time scale, facilitating a heat wave and a source of MeV electrons that penetrate and heat the bulk target. Collision-less effects heat the surface effectively starting at the relativistic intensity threshold, independent of plasma density. Our numerical results show that a high-contrast 1J/100fs laser can drive a solid target into the warm dense matter regime. This system is suitable to ab-initio modeling and experimental probing. Work performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. The interaction of intense ultrashort laser pulses with cryogenic He jets

    CERN Document Server

    Shihab, M; Redmer, R

    2016-01-01

    We study the interaction of intense ultrashort laser pulses with cryogenic He jets using 2d/3v relativistic Particle-in-Cell simulations (XOOPIC). Of particular interest are laser intensities $(10^{15}-10^{20})$ W/cm$^2$, pulse lengths $\\le 100$ fs, and the frequency regime $\\sim 800$ nm for which the jets are initially transparent and subsequently not homogeneously ionized. Pulses $\\ge 10^{16}$ W/cm$^2$ are found to drive ionization along the jet and outside the laser spot, the ionization-front propagates along the jet at a fraction of the speed of light. Within the ionized region, there is a highly transient field, which may be interpreted as two-surface wave decay and as a result of the charge-neutralizing disturbance at the jet-vacuum interface. The ionized region has solid-like densities and temperatures of few to hundreds of eV, i.e., warm and hot dense matter regimes. Such extreme conditions are relevant for high-energy densities as found, e.g., in shock-wave experiments and inertial confinement fusion...

  7. Modeling the interaction of light intensity, nutrient concentration and uranium toxicity in Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, E.; Horemans, N.; Vandenhove, H. [Belgian Nuclear Research Centre SCK-CEN (Belgium); Cedergreen, N. [University of Copenhagen (Denmark); Jager, T. [Vrije Universiteit Amsterdam (Netherlands)

    2014-07-01

    Radioecology aims at assessing the effect of radionuclides and radiation on the environment. Since we cannot test every possible environmental situation in the laboratory, we need modeling approaches to extrapolate the results of toxicity assays to environmentally relevant scenarios. Therefore, it is of crucial importance to understand the effect of relevant environmental factors, such as nutrients, temperature and light on the toxicity of the test. Radionuclides are often found to induce the production of reactive oxygen species (ROS). In plants, an overload of ROS can lead to disturbances of the photosynthetic system. Since the light intensity determines the efficiency of the photo-systems in plants, it can be expected to interact with the effect of radionuclides. The nutrient concentration of the test medium determines the physiological state of the plant, affecting in turn the plant's capability of dealing with stress and hence influences the toxicity of the contaminant. To study the interaction of stressors with environmental conditions, mechanistic effect modeling is promoted widely in ecotoxicology. In principle, the modelling aims at a mechanistic understanding of the different processes causing the stress individually, and integrating them in one framework to study their joint effect and possible interaction. We here present a mechanistic effect model for Lemna minor (common duckweed), which is based on Dynamic Energy Budget (DEB) theory. Models based on DEB have been used widely to study the effects of compounds on animals. Due to its general applicability to all types of organisms, it holds potential to be used for comparison of species and compounds in a broad context. Energy uptake from the environment is modeled explicitly, and metabolic rates are set to depend on temperature in DEB models. Therefore, they can be used to extrapolate effects to a wide range of environmentally relevant scenarios. Until now, the DEB research in ecotoxicology has

  8. Prevalence of potential drug interactions in patients in an intensive care unit of a university hospital in Brazil

    Directory of Open Access Journals (Sweden)

    Adriano Max Moreira Reis

    2011-01-01

    Full Text Available OBJECTIVES: To investigate the prevalence of potential drug interactions at the intensive care unit of a university hospital in Brazil and to analyze their clinical significance. METHODS: This cross-sectional retrospective study included 299 patients who had been hospitalized in the intensive care unit of the hospital. The drugs administered during the first 24 hours of hospitalization, in the 50th length-ofstay percentile and at the time of discharge were analyzed to identify potential drug-drug and drug-enteral nutrition interactions using DRUG-REAXH software. The drugs were classified according to the anatomical therapeutic chemical classification. RESULTS: The median number of medications per patient was smaller at the time of discharge than in the 50th length-of-stay percentile and in the first 24 hours of hospitalization. There was a 70% prevalence of potential drug interactions at the intensive care unit at the studied time points of hospitalization. Most of the drug interactions were either severe or moderate, and the scientific evidence for the interactions was, in general, either good or excellent. Pharmacodynamic interactions presented a subtle predominance in relation to pharmacokinetic interactions. The occurrence of potential drug interactions was associated with the number of medications administered and the length of stay. Medications that induced cytochrome P450, drugs that prolong the QT interval and cardiovascular drugs were pharmacotherapy factors associated with potential drug interactions. CONCLUSION: The study showed that potential drug interactions were prevalent in the intensive care unit due to the complexity of the pharmacotherapies administered. The interactions were associated with the number of drugs, the length of stay and the characteristics of the administered medications.

  9. Interactions of subglottal pressure and neuromuscular activation on fundamental frequency and intensity.

    Science.gov (United States)

    Chhetri, Dinesh K; Park, Soo Jin

    2016-05-01

    Fundamental frequency (F0) and intensity sound pressure level (SPL) of voice are controlled by intrinsic laryngeal muscle (ILM) activation and subglottal pressure (Psub). Their interactions were investigated. In an in vivo canine model, the thyroarytenoid (TA), lateral cricoarytenoid/interarytenoid (LCA/IA), and cricothyroid (CT) muscles were independently activated from threshold to maximal contraction by neuromuscular stimulation in various combinations, whereas airflow was increased to phonation onset pressure and beyond. The resultant acoustic output was analyzed for effects of Psub on vibratory stability, F0, and SPL. Muscle activation plots and vocal range profiles by individual ILM activation states were analyzed. Cricothyroid activation increased phonation onset F0, but vibration was less stable in high CT conditions and displayed vibratory mode change. In addition, a decrease in F0 with increased Psub was observed in high CT conditions. Intensity increased with Psub in all conditions, but the slope was greater at high CT, low TA/LCA/IA activations. Lateral cricoarytenoid/interarytenoid activation improved vocal efficiency. To maintain same F0 with increasing SPL (messa di voce), TA activation was decreased and LCA/IA activation was increased. The same F0 and SPL could be achieved with a variety of ILM activation combinations. Cricothyroid is primarily required for increasing F0, whereas TA can increase or decrease F0 and SPL. Lateral cricoarytenoid/interarytenoid activation likely maintains vocal fold adduction during increased Psub and improves vocal efficiency. This study also demonstrates laryngeal motor equivalence, the ability of the larynx to achieve the same target F0 and SPL with multiple combinations of ILM activation. N/A. Laryngoscope, 126:1123-1130, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  10. The interaction of intense ultrashort laser pulses with cryogenic He planar jets

    Science.gov (United States)

    Shihab, M.; Bornath, Th; Redmer, R.

    2017-04-01

    We study the interaction of intense ultrashort laser pulses with cryogenic He planar jets, i.e., slabs, using 2D3V relativistic particle-in-cell simulations. Of particular interest are laser intensities ({10}15{--}{10}20) W cm‑2, pulse lengths ≤100 fs, and the wave length regime ∼800 nm for which the slabs are initially transparent and subsequently inhomogeneously ionized. Pulses ≥slant {10}16 W cm‑2 are found to drive ionization along the slab and outside the laser spot, the ionization front propagates along the slab at a considerable fraction of the speed of light. Within the ionized region, there is a highly transient field which is a result of the charge-neutralizing disturbance at the slab-vacuum interface and which may be interpreted in terms of a two-surface-wave decay. The ionized region is predicted to reach solid-like densities and temperatures of few to hundreds of eV, i.e., it belongs to warm and hot dense matter regimes. Such extreme conditions are relevant for high-energy densities as found, e.g., in shock-wave experiments and inertial confinement fusion studies. The temporal evolution of the ionization is studied considering theoretically a pump–probe x-ray Thomson scattering scheme. We observe plasmon and non-collective modes that are generated in the slab, and their amplitude is proportional to the ionized volume. Our theoretical findings could be tested at free-electron laser facilities such as FLASH and the European XFEL (Hamburg) and the LCLS (Stanford).

  11. A theoretical scheme for generation of Gazeau-Klauder coherent states via intensity-dependent degenerate Raman interaction

    CERN Document Server

    Yadollahi, F; 10.1016/j.optcom.2010.09.062

    2010-01-01

    A theoretical scheme is presented for generating Gazeau-Klauder coherent states(GKCSs) via the generalization of degenerate Raman interaction with coupling constant to intensity-dependent coupling. Firstly, we prove that in the intensity-dependent degenerate Raman interaction, under particular conditions, the modified efective Hamiltonian can be used instead of Hamiltonian in the interaction picture, for describing the atom-field interaction. We suppose that the cavity field is initially prepared in a nonlinear CS, which is not temporally stable. As we will observe, after the occurrence of the interaction between atom and field, the generated state involves a superposition of GKCSs which are temporally stable and initial nonlinear CS. Under specific conditions which may be prepared, the generated state just includes GKCS. So, in this way we produced the GKCS, successfully.

  12. High Intensity Femtosecond XUV Pulse Interactions with Atomic Clusters: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Ditmire, Todd [Univ. of Texas, Austin, TX (United States). Center for High Energy Density Science

    2016-10-12

    We propose to expand our recent studies on the interactions of intense extreme ultraviolet (XUV) femtosecond pulses with atomic and molecular clusters. The work described follows directly from work performed under BES support for the past grant period. During this period we upgraded the THOR laser at UT Austin by replacing the regenerative amplifier with optical parametric amplification (OPA) using BBO crystals. This increased the contrast of the laser, the total laser energy to ~1.2 J , and decreased the pulse width to below 30 fs. We built a new all reflective XUV harmonic beam line into expanded lab space. This enabled an increase influence by a factor of 25 and an increase in the intensity by a factor of 50. The goal of the program proposed in this renewal is to extend this class of experiments to available higher XUV intensity and a greater range of wavelengths. In particular we plan to perform experiments to confirm our hypothesis about the origin of the high charge states in these exploding clusters, an effect which we ascribe to plasma continuum lowering (ionization potential depression) in a cluster nano-­plasma. To do this we will perform experiments in which XUV pulses of carefully chosen wavelength irradiate clusters composed of only low-Z atoms and clusters with a mixture of this low-­Z atom with higher Z atoms. The latter clusters will exhibit higher electron densities and will serve to lower the ionization potential further than in the clusters composed only of low Z atoms. This should have a significant effect on the charge states produced in the exploding cluster. We will also explore the transition of explosions in these XUV irradiated clusters from hydrodynamic expansion to Coulomb explosion. The work proposed here will explore clusters of a wider range of constituents, including clusters from solids. Experiments on clusters from solids will be enabled by development we performed during the past grant period in which we constructed and

  13. Experimental Research of Fast Proton Generation From Ultra-short Intense Laser Pulses Interaction With Different Thickness Al Foils

    Institute of Scientific and Technical Information of China (English)

    LAN; Xiao-fei; LU; Jian-xin; HUANG; Yong-sheng; WANG; Lei-jian; XI; Xiao-feng; TANG; Xiu-zhang

    2012-01-01

    <正>With the development of laser technology, the generation of fast ions by the interaction of ultra-short ultra-intense laser pulses with matters has recently been attracting considerable attention, especially for acceleration of proton. Before performing experiment, we calibrated the CR39 detector using standard proton beams from conventional accelerator. In the field of proton acceleration driven by ultra-short ultra-intense laser pulses,

  14. Collisionless absorption, hot electron generation, and energy scaling in intense laser-target interaction

    CERN Document Server

    Liseykina, T; Murakami, M

    2014-01-01

    Among the various attempts to understand collisionless absorption of intense ultrashort laser pulses a variety of models has been invented to describe the laser beam target interaction. In terms of basic physics collisionless absorption is understood now as the interplay of the oscillating laser field with the space charge field produced in the plasma. A first approach to this idea is realized in Brunel's model the essence of which consists in the formation of an oscillating charge cloud in the vacuum in front of the target. The investigation of statistical ensembles of orbits shows that the absorption process is localized at the ion-vacuum interface and in the skin layer: Single electrons enter into resonance with the laser field thereby undergoing a phase shift which causes orbit crossing and braking of Brunel's laminar flow. This anharmonic resonance acts like an attractor for the electrons and leads to the formation of a Maxwellian tail in the electron energy spectrum. Most remarkable results of our inves...

  15. Longitudinal Ion Acceleration from High-Intensity Laser Interactions with Underdense Plasma

    CERN Document Server

    Willingale, L; Nilson, P M; Clarke, R J; Dangor, A E; Kaluza, M C; Karsch, S; Lancaster, K L; Mori, W B; Schreiber, J; Thomas, A G R; Wei, M S; Krushelnick, K; Najmudin, Z

    2007-01-01

    Longitudinal ion acceleration from high-intensity (I ~ 10^20 Wcm^-2) laser interactions with helium gas jet targets (n_e ~ 0.04 n_c) have been observed. The ion beam has a maximum energy for He^2+ of approximately 40 MeV and was directional along the laser propagation path, with the highest energy ions being collimated to a cone of less than 10 degrees. 2D particle-in-cell simulations have been used to investigate the acceleration mechanism. The time varying magnetic field associated with the fast electron current provides a contribution to the accelerating electric field as well as providing a collimating field for the ions. A strong correlation between the plasma density and the ion acceleration was found. A short plasma scale-length at the vacuum interface was observed to be beneficial for the maximum ion energies, but the collimation appears to be improved with longer scale-lengths due to enhanced magnetic fields in the ramp acceleration region.

  16. Microstructure evolution of laser solid forming of Ti-A1-V ternary system alloys from blended elemental powders

    Institute of Scientific and Technical Information of China (English)

    Hua Tan; Fengying Zhang; Jing Chen; Xin Lin; Weidong Huang

    2011-01-01

    @@ Morphology evolution of prior β grains of laser solid forming (LSF) Ti-xAl-yV (x ≤ 11,y ≤ 20) alloys from blended elemental powders is investigated.The formation mechanism of grain morphology is revealed by incorporating columnar to equiaxed transition (CET) mechanism during solidification.%Morphology evolution of prior β grains of laser solid forming (LSF) Ti-xAl-yV (x ≤ 11,y ≤ 20) alloys from blended elemental powders is investigated. The formation mechanism of grain morphology is revealed by incorporating columnar to equiaxed transition (CET) mechanism during solidification. The morphology of prior β grains of LSF Ti-6Al-yV changes from columnar to equiaxed grains with increasing element V content from 4 to 20 wt.-%. This agrees well with CET theoretical prediction. Likewise, the grain morphology of LSF Ti-xA1-2V from blended elemental powders changes from large columnar to small equiaxed with increasing A1 content from 2 to 11 wt.-%. The macro-morphologies of LSF Ti-8A1-2V and Ti-11A1-2V from blended elemental powders do not agree with CET predictions. This is caused by the increased disturbance effects of mixing enthalpy with increasing A1 content, generated in the alloying process of Ti, Al, and V in the molten pool.

  17. Collisionless absorption, hot electron generation, and energy scaling in intense laser-target interaction

    Energy Technology Data Exchange (ETDEWEB)

    Liseykina, T., E-mail: tatyana.tiseykina@uni-rostock.de [Institut für Physik, Universität Rostock, Universitätsplatz 3, 18051 Rostock (Germany); Institute of Computational Technologies SD RAS, Acad. Lavrentjev Ave. 6, 630090 Novosibirsk (Russian Federation); Mulser, P. [Theoretical Quantum Electronics, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan)

    2015-03-15

    Among the various attempts to understand collisionless absorption of intense and superintense ultrashort laser pulses, a whole variety of models and hypotheses has been invented to describe the laser beam target interaction. In terms of basic physics, collisionless absorption is understood now as the interplay of the oscillating laser field with the space charge field produced by it in the plasma. A first approach to this idea is realized in Brunel's model the essence of which consists in the formation of an oscillating charge cloud in the vacuum in front of the target, therefore frequently addressed by the vague term “vacuum heating.” The investigation of statistical ensembles of orbits shows that the absorption process is localized at the ion-vacuum interface and in the skin layer: Single electrons enter into resonance with the laser field thereby undergoing a phase shift which causes orbit crossing and braking of Brunel's laminar flow. This anharmonic resonance acts like an attractor for the electrons and leads to the formation of a Maxwellian tail in the electron energy spectrum. Most remarkable results of our investigations are the Brunel like spectral hot electron distribution at the relativistic threshold, the minimum of absorption at Iλ{sup 2}≅(0.3−1.2)×10{sup 21} Wcm{sup −2}μm{sup 2} in the plasma target with the electron density of n{sub e}λ{sup 2}∼10{sup 23}cm{sup −3}μm{sup 2}, the drastic reduction of the number of hot electrons in this domain and their reappearance in the highly relativistic domain, and strong coupling, beyond expectation, of the fast electron jets with the return current through Cherenkov emission of plasmons. The hot electron energy scaling shows a strong dependence on intensity in the moderately relativistic domain Iλ{sup 2}≅(10{sup 18}−10{sup 20}) Wcm{sup −2}μm{sup 2}, a scaling in vague accordance with current published estimates in the range Iλ{sup 2}≅(0.14−3.5)×10{sup 21}

  18. Transverse Dynamics and Energy Tuning of Fast Electrons Generated in Sub-Relativistic Intensity Laser Pulse Interaction with Plasmas

    CERN Document Server

    Mori, M; Daito, I; Kotaki, H; Hayashi, Y; Yamazaki, A; Ogura, K; Sagisaka, A; Koga, J; Nakajima, K; Daido, H; Bulanov, S V; Kimura, T

    2006-01-01

    The regimes of quasi-mono-energetic electron beam generation were experimentally studied in the sub-relativistic intensity laser plasma interaction. The observed electron acceleration regime is unfolded with two-dimensional-particle-in-cell simulations of laser-wakefield generation in the self-modulation regime.

  19. Intensive Interaction as a Novel Approach in Social Care: Care Staff's Views on the Practice Change Process

    Science.gov (United States)

    Firth, Graham; Elford, Helen; Leeming, Catherine; Crabbe, Marion

    2008-01-01

    Background: Intensive Interaction is an approach to developing the pre-verbal communication and sociability of people with severe or profound and multiple learning disabilities and autism. Previous research has indicated many potential benefits; however, the approach is not consistently used in social care. Aim: To report on the significant and…

  20. Interactive effects of herbivory and competition intensity determine invasive plant performance.

    Science.gov (United States)

    Huang, Wei; Carrillo, Juli; Ding, Jianqing; Siemann, Evan

    2012-10-01

    Herbivory can reduce plant fitness, and its effects can be increased by competition. Though numerous studies have examined the joint effects of herbivores and competitors on plant performance, these interactive effects are seldom considered in the context of plant invasions. Here, we examined variation in plant performance within a competitive environment in response to both specialist and generalist herbivores using Chinese tallow as a model species. We combined tallow plants from native and invasive populations to form all possible pairwise combinations, and designated invasive populations as stronger neighbours and native populations as weaker neighbours. We found that when no herbivory was imposed, invasive populations always had higher total biomass than natives, regardless of their neighbours, which is consistent with our assumption of increased competitive ability. Defoliation by either generalist or specialist herbivores suppressed plant growth but the effects of specialists were generally stronger for invasive populations. Invasive populations had their lowest biomass when fed upon by specialists while simultaneously competing with stronger neighbours. The root/shoot ratios of invasive populations were lower than those of native populations under almost all conditions, and invasive plants were taller than native plants overall, especially when herbivores were present, suggesting that invasive populations may adopt an "aboveground first" strategy to cope with herbivory and competition. These results suggest that release from herbivores, especially specialists, improves an invader's performance and helps to increase its competitive ability. Therefore, increasing interspecific competition intensity by planting a stronger neighbour while simultaneously releasing a specialist herbivore may be an especially effective method of managing invasive plants.

  1. Pair plasma formation in the interaction of a thin plasma with ultra-intense counter-propagating lasers

    Science.gov (United States)

    Slade-Lowther, Cody

    2016-10-01

    Next-generation lasers (e.g. ELI) expect to reach peak intensities of 1023 Wcm-2. At such intensities, the electromagnetic field strength is sufficient for non-linear Quantum Electrodynamics effects to become important. The processes of non-linear Compton scattering and Breit-Wheeler Pair production become likely at intensities >=1023 Wcm-2, and have been predicted to lead to prolific pair and γ-ray production via electromagnetic cascades. We present results for the case of two counter-propagating circularly- polarized lasers of intensity I ∈ [1023 ,1025 ] Wcm24 interacting with a plasma of initial density n0 ∈ [1025 ,1035 ] via the Monte-Carlo- particle-in-cell code EPOCH. We show the maximum pair plasma density in I vs n0 space. We further discuss the variation within this space on the plasma characteristics, including laser absorption and field-particle energy distribution.

  2. Bremsstrahlung production with high-intensity laser matter interactions and applications

    NARCIS (Netherlands)

    Galy, J.; Maucec, M.; Hamilton, D. J.; Edwards, R.; Magill, J.

    2007-01-01

    In the last decade an evolution of experimental relativistic laser-plasma physics has led to highly sophisticated lasers, which are now able to generate ultra short pulses and can be focused to intensities in excess of 10(21) W cm(-2), with more than 500 J on target. In the intense electric field of

  3. Bremsstrahlung production with high-intensity laser matter interactions and applications

    NARCIS (Netherlands)

    Galy, J.; Maucec, M.; Hamilton, D. J.; Edwards, R.; Magill, J.

    2007-01-01

    In the last decade an evolution of experimental relativistic laser-plasma physics has led to highly sophisticated lasers, which are now able to generate ultra short pulses and can be focused to intensities in excess of 10(21) W cm(-2), with more than 500 J on target. In the intense electric field of

  4. Study of 2 and 3/2 harmonics in ultrashort high-intensity laser plasma interaction

    Indian Academy of Sciences (India)

    V Arora; P A Naik; J A Chakera; R A Khan; P D Gupta

    2010-12-01

    An experimental study is presented on measurements of optical spectrum of the laser light scattered from solid surface irradiated by Ti:sapphire laser pulses up to an intensity of 1.2 × 1018 W cm-2. The spectrum has well-defined peaks at wavelengths corresponding to 2 and 3/2 radiations. The spectral features vary with the laser intensity and show blue-shift with increasing laser intensity. At a constant laser fluence, the spectrum is red-shifted with increasing laser pulse duration. The observed results are explained in terms of the density scale length variation of the plasma and laser chirp.

  5. Interactive effects of photoperiod and light intensity on blood physiological and biochemical reactions of broilers grown to heavy weights.

    Science.gov (United States)

    Olanrewaju, H A; Purswell, J L; Collier, S D; Branton, S L

    2013-04-01

    The effects of photoperiod, light intensity, and their interaction on blood acid-base balance, metabolites, and electrolytes in broiler chickens under environmentally controlled conditions were examined in 2 trials. A 3 × 3 factorial experiment in a randomized complete block design was used in this study. In each trial, all treatment groups were provided 23L:1D with 20 lx of intensity from placement to 7 d, and then subjected to the treatments. The 9 treatments consisted of 3 photoperiods [long/continuous (23L:1D) from d 8 to 56, regular/intermittent (2L:2D), and short/nonintermittent (8L:16D) from d 8 to 48 and 23L:1D from d 49 to 56, respectively] and exposure to 3 light intensities (10, 5.0, and 0.5 lx) from d 8 through d 56 at 50% RH. Feed and water were provided ad libitum. Venous blood samples were collected on d 7, 14, 28, 42, and 56. Main effects indicated that short/nonintermittent photoperiod significantly (P light intensity, or their interaction. There was no effect of light intensity on most of the blood variables examined. Acid-base regulation during photoperiod and light intensity exposure did not deteriorate despite a lower pH and higher partial pressure of CO2 with normal HCO3(-). These results indicate that continuous exposure of broiler chickens to varying light intensities had a minor effect on blood physiological variables, whereas the short photoperiod markedly affected most blood physiological variables without inducing physiological stress in broilers.

  6. Exploring the "intensity fading" phenomenon in the study of noncovalent interactions by MALDI-TOF mass spectrometry

    DEFF Research Database (Denmark)

    Yanes, Oscar; Aviles, Francesc X; Roepstorff, Peter;

    2007-01-01

    The difficulties to detect intact noncovalent complexes involving proteins and peptides by MALDI-TOF mass spectrometry have hindered a widespread use of this approach. Recently, "intensity fading MS" has been presented as an alternative strategy to detect noncovalent interactions in solution...... the intensity fading phenomenon, as well as a comparison with the strategy based on the direct detection of intact complexes by MALDI MS. For this purpose, the study is focused on two different protease-inhibitor complexes naturally occurring in solution, together with a heterogeneous mixture of nonbinding...

  7. Generation of higher order nonclassical states via interaction of intense electromagnetic field with third order nonlinear medium

    CERN Document Server

    Pathak, A

    2006-01-01

    Interaction of intense laser beam with an inversion symmetric third order nonlinear medium is modeled as a quartic anharmonic oscillator. A first order operator solution of the model Hamiltonian is used to study the possibilities of generation of higher order nonclassical states. It is found that the higher order squeezed and higher order antibunched states can be produced by this interaction. It is also shown that the higher order nonclassical states may appear separately, i.e. a higher order antibunched state is not essentially higher order squeezed state and vice versa.

  8. Controlled electron bunch generation in the few-cycle ultra-intense laser–solid interaction scenario

    Energy Technology Data Exchange (ETDEWEB)

    Kluge, T., E-mail: t.kluge@hzdr.de; Bussmann, M.; Cowan, T.E.; Schramm, U.

    2016-09-01

    The generation of Maxwellian or exponentially decaying spectra in the interaction of ultra-intense ultra-short laser pulses with solid foils is very general observation both in experiments and simulations. Yet, the physical origin of this observation is not well understood. For a very idealized situation of plane wave, plane and cold target interaction, we show that both randomization between individual electron bunches accelerated by the laser through the plasma as well as randomization during a single bunch are not observable in particle-in-cell simulations. Hence they are not accountable for the apparent thermalization (exponential spectrum).

  9. Enhanced laser absorption from radiation pressure in intense laser plasma interactions

    Science.gov (United States)

    Dollar, F.; Zulick, C.; Raymond, A.; Chvykov, V.; Willingale, L.; Yanovsky, V.; Maksimchuk, A.; Thomas, A. G. R.; Krushelnick, K.

    2017-06-01

    The reflectivity of a short-pulse laser at intensities of 2× {10}21 {{Wcm}}-2 with ultra-high contrast ({10}-15) on sub-micrometer silicon nitride foils was studied experimentally using varying polarizations and target thicknesses. The reflected intensity and beam quality were found to be relatively constant with respect to intensity for bulk targets. For submicron targets, the measured reflectivity drops substantially without a corresponding increase in transmission, indicating increased conversion of fundamental to other wavelengths and particle heating. Experimental results and trends observed in 3D particle-in-cell simulations emphasize the critical role of ion motion due to radiation pressure on the absorption process. Ion motion during ultra-short pulses enhances the electron heating, which subsequently transfers more energy to the ions.

  10. High-intensity X-rays interaction with matter processes in plasmas, clusters, molecules and solids

    CERN Document Server

    Hau-Riege, Stefan P

    2012-01-01

    Filling the need for a book bridging the effect of matter on X-ray radiation and the interaction of x-rays with plasmas, this monograph provides comprehensive coverage of the topic. As such, it presents and explains such powerful new X-ray sources as X-ray free-electron lasers, as well as short pulse interactions with solids, clusters, molecules, and plasmas, and X-ray matter interactions as a diagnostic tool. Equally useful for researchers and practitioners working in the field.

  11. Laser-matter interaction at high intensity and high temporal contrast; Interaction laser matiere a haut flux et fort contraste temporel

    Energy Technology Data Exchange (ETDEWEB)

    Doumy, G

    2006-01-15

    The continuous progress in the development of laser installations has already lead to ultra-short pulses capable of achieving very high focalized intensities (I > 10{sup 18} W/cm{sup 2}). At these intensities, matter presents new non-linear behaviours, due to the fact that the electrons are accelerated to relativistic speeds. The experimental access to this interaction regime on solid targets has long been forbidden because of the presence, alongside the femtosecond pulse, of a pedestal (mainly due to the amplified spontaneous emission (ASE) which occurs in the laser chain) intense enough to modify the state of the target. In this thesis, we first characterized, both experimentally and theoretically, a device which allows an improvement of the temporal contrast of the pulse: the Plasma Mirror. It consists in adjusting the focusing of the pulse on a dielectric target, so that the pedestal is mainly transmitted, while the main pulse is reflected by the overcritical plasma that it forms at the surface. The implementation of such a device on the UHI 10 laser facility (CEA Saclay - 10 TW - 60 fs) then allowed us to study the interaction between ultra-intense, high contrast pulses with solid targets. In a first part, we managed to generate and characterize dense plasmas resulting directly from the interaction between the main pulse and very thin foils (100 nm). This characterization was realized by using an XUV source obtained by high order harmonics generation in a rare gas jet. In a second part, we studied experimentally the phenomenon of high order harmonics generation on solid targets, which is still badly understood, but could potentially lead to a new kind of energetic ultra-short XUV sources. (author)

  12. Attospiral generation upon interaction of circularly polarized intense laser pulses with cone-like targets

    CERN Document Server

    Lécz, Zsolt

    2015-01-01

    Generation of high intensity attopulses is investigated in cylindrical geometry by using 3D particle-in-cell plasma simulation code. Due to the rotation symmetric target, a circularly polarized laser pulse is considered propagating on the axis of a hollow cone-like target. The large incidence angle and constant ponderomotive pressure leads to nano-bunching of relativistic electrons responsible for the laser-driven synchrotron emission. A numerical method is developed to find the source and direction of the coherent radiation that is responsible for the existence of attopulses. The intensity modulation in the harmonic spectrum is well described by the model of coherent synchrotron emission extended to the regime of higher order \\gamma-spikes. The spatial distribution of the higher harmonics resembles a spiral shape which gets focused into a small volume behind the target.

  13. Interaction of Clusters with Intense, Few-Cycle, Long Wavelength Fields

    Science.gov (United States)

    2015-11-05

    spectral region. We have finished the construction of TOF spectrometer cluster beam machine by which several intriguing phenomena have been observed. The...intense laser in the mid-infrared spectral region (1-4.5 micron). Applications are in the perspective included the production of highly charged, energetic...title and subtitle with volume number and part number, if applicable. On classified documents, enter the title classification in parentheses. 5a

  14. Contrasting Effects of Land Use Intensity and Exotic Host Plants on the Specialization of Interactions in Plant-Herbivore Networks

    Science.gov (United States)

    de Araújo, Walter Santos; Vieira, Marcos Costa; Lewinsohn, Thomas M.; Almeida-Neto, Mário

    2015-01-01

    Human land use tends to decrease the diversity of native plant species and facilitate the invasion and establishment of exotic ones. Such changes in land use and plant community composition usually have negative impacts on the assemblages of native herbivorous insects. Highly specialized herbivores are expected to be especially sensitive to land use intensification and the presence of exotic plant species because they are neither capable of consuming alternative plant species of the native flora nor exotic plant species. Therefore, higher levels of land use intensity might reduce the proportion of highly specialized herbivores, which ultimately would lead to changes in the specialization of interactions in plant-herbivore networks. This study investigates the community-wide effects of land use intensity on the degree of specialization of 72 plant-herbivore networks, including effects mediated by the increase in the proportion of exotic plant species. Contrary to our expectation, the net effect of land use intensity on network specialization was positive. However, this positive effect of land use intensity was partially canceled by an opposite effect of the proportion of exotic plant species on network specialization. When we analyzed networks composed exclusively of endophagous herbivores separately from those composed exclusively of exophagous herbivores, we found that only endophages showed a consistent change in network specialization at higher land use levels. Altogether, these results indicate that land use intensity is an important ecological driver of network specialization, by way of reducing the local host range of herbivore guilds with highly specialized feeding habits. However, because the effect of land use intensity is offset by an opposite effect owing to the proportion of exotic host species, the net effect of land use in a given herbivore assemblage will likely depend on the extent of the replacement of native host species with exotic ones. PMID

  15. Controlling two plasmon decay instability in intense femtosecond laser driven plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Prashant Kumar; Adak, Amitava; Lad, Amit D.; Chatterjee, Gourab; Ravindra Kumar, G., E-mail: grk@tifr.res.in [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005 (India); Brijesh, P. [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005 (India); UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India)

    2015-11-15

    We investigate the onset of the two-plasmon-decay (TPD) instability in intense femtosecond laser-solid interaction. In particular, this instability, originating at the quarter critical electron density surface in the inhomogeneous plasma, is explored for a wide range of laser parameters-energy, pulse duration, and intensity contrast. By varying these laser parameters, we demonstrate ways to excite and control the growth of the TPD process. The pulse duration scan carried out under a constant laser fluence reveals the pulse width dependent nature of TPD growth. The spectral splitting of the TPD induced three-halves harmonic emission is used to infer the electron temperature near the quarter critical density surface. Moreover, by varying the laser contrast over four orders of magnitude, we find that the intensity threshold of three-halves harmonic emission increases by nearly two orders of magnitude. This contrast dependent intensity threshold for the emission of three-halves harmonic can be a useful diagnostic of the laser contrast.

  16. An in-vacuo optical levitation trap for high-intensity laser interaction experiments with isolated microtargets

    Energy Technology Data Exchange (ETDEWEB)

    Price, C. J., E-mail: c.price10@imperial.ac.uk; Giltrap, S.; Stuart, N. H.; Parker, S.; Patankar, S.; Lowe, H. F.; Smith, R. A. [Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Donnelly, T. D. [Department of Physics, Harvey Mudd College, Claremont, California 91711 (United States); Drew, D.; Gumbrell, E. T. [Radiation Physics, AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom)

    2015-03-15

    We report on the design, construction, and characterisation of a new class of in-vacuo optical levitation trap optimised for use in high-intensity, high-energy laser interaction experiments. The system uses a focused, vertically propagating continuous wave laser beam to capture and manipulate micro-targets by photon momentum transfer at much longer working distances than commonly used by optical tweezer systems. A high speed (10 kHz) optical imaging and signal acquisition system was implemented for tracking the levitated droplets position and dynamic behaviour under atmospheric and vacuum conditions, with ±5 μm spatial resolution. Optical trapping of 10 ± 4 μm oil droplets in vacuum was demonstrated, over timescales of >1 h at extended distances of ∼40 mm from the final focusing optic. The stability of the levitated droplet was such that it would stay in alignment with a ∼7 μm irradiating beam focal spot for up to 5 min without the need for re-adjustment. The performance of the trap was assessed in a series of high-intensity (10{sup 17} W cm{sup −2}) laser experiments that measured the X-ray source size and inferred free-electron temperature of a single isolated droplet target, along with a measurement of the emitted radio-frequency pulse. These initial tests demonstrated the use of optically levitated microdroplets as a robust target platform for further high-intensity laser interaction and point source studies.

  17. An in-vacuo optical levitation trap for high-intensity laser interaction experiments with isolated microtargets.

    Science.gov (United States)

    Price, C J; Donnelly, T D; Giltrap, S; Stuart, N H; Parker, S; Patankar, S; Lowe, H F; Drew, D; Gumbrell, E T; Smith, R A

    2015-03-01

    We report on the design, construction, and characterisation of a new class of in-vacuo optical levitation trap optimised for use in high-intensity, high-energy laser interaction experiments. The system uses a focused, vertically propagating continuous wave laser beam to capture and manipulate micro-targets by photon momentum transfer at much longer working distances than commonly used by optical tweezer systems. A high speed (10 kHz) optical imaging and signal acquisition system was implemented for tracking the levitated droplets position and dynamic behaviour under atmospheric and vacuum conditions, with ±5 μm spatial resolution. Optical trapping of 10 ± 4 μm oil droplets in vacuum was demonstrated, over timescales of >1 h at extended distances of ∼40 mm from the final focusing optic. The stability of the levitated droplet was such that it would stay in alignment with a ∼7 μm irradiating beam focal spot for up to 5 min without the need for re-adjustment. The performance of the trap was assessed in a series of high-intensity (10(17) W cm(-2)) laser experiments that measured the X-ray source size and inferred free-electron temperature of a single isolated droplet target, along with a measurement of the emitted radio-frequency pulse. These initial tests demonstrated the use of optically levitated microdroplets as a robust target platform for further high-intensity laser interaction and point source studies.

  18. An investigation of the interaction of intense laser radiation with molecules of sulfur hexafluoride through the buffer gas technique

    Science.gov (United States)

    Eletskii, A. V.; Klimov, V. D.; Udalova, T. A.

    1981-02-01

    Measurements of the coefficient of the absorption of intense (approximately 10 to the 7th W/sq cm) radiation from a CO2 laser by SF6 molecules in the presence of noble gases and at pressures up to 40 bars are presented. The dependence of the coefficient of absorption on the pressure and type of buffer gas, as well as on the wavelength and intensity of the incident radiation, makes it possible to follow the formation of the vibrational state distribution function of the molecules. The character of the distribution function depends on the competition between vibrational relaxation processes and laser radiation absorption. At high pressures, that is, at helium pressures greater than approximately 20-40 bars, a two-level scheme for the interaction of intense laser radiation with SF6 is implemented experimentally for the first time. Here, molecules excited by light to the v = 1 state relax instantaneously upon collision. The dependence of the rate constant for the destruction of SF6 molecular states on the number of the vibrational level v upon collision with helium atoms can be evaluated from the experimental data. Taken as a whole, the data confirm the assumption of the linear, single-photon nature of the interaction of laser radiation with SF6 molecules.

  19. Linking market interaction intensity of 3D Ising type financial model with market volatility

    Science.gov (United States)

    Fang, Wen; Ke, Jinchuan; Wang, Jun; Feng, Ling

    2016-11-01

    Microscopic interaction models in physics have been used to investigate the complex phenomena of economic systems. The simple interactions involved can lead to complex behaviors and help the understanding of mechanisms in the financial market at a systemic level. This article aims to develop a financial time series model through 3D (three-dimensional) Ising dynamic system which is widely used as an interacting spins model to explain the ferromagnetism in physics. Through Monte Carlo simulations of the financial model and numerical analysis for both the simulation return time series and historical return data of Hushen 300 (HS300) index in Chinese stock market, we show that despite its simplicity, this model displays stylized facts similar to that seen in real financial market. We demonstrate a possible underlying link between volatility fluctuations of real stock market and the change in interaction strengths of market participants in the financial model. In particular, our stochastic interaction strength in our model demonstrates that the real market may be consistently operating near the critical point of the system.

  20. Effect of radiation damping on the interaction of ultra-intense laser pulses with an overdense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, Alexei; Koga, James; Sasaki, Akira; Ueshima, Yutaka [Japan Atomic Energy Research Inst., Advanced Photon Research Center, Neyagawa, Osaka (Japan)

    2001-10-01

    The effect of radiation damping on the interaction of an ultra-intense laser pulse with an overdense plasma is studied via relativistic particle-in-cell simulation. The calculation is performed for a Cu solid slab including ionization. We find a strong effect from radiation damping on the electron energy cut-off at about 150 MeV and on the absorption of a laser pulse with an intensity I=5x10{sup 22} W/cm{sup 2} and duration of 20 fs. Hot electrons reradiate more then 10% of the laser energy during the laser pulse. With the laser intensity, the energy loss due to the radiation damping increases as I{sup 3}. In addition, we observe that the laser pulse may not propagate in the plasma even if {omega}{sub pl}{sup 2}/{omega}{sup 2}{gamma}<1. The increase of skin depth with the laser intensity due to relativistic effects gives rise to the absorption efficiency. (author)

  1. Laser induced periodic surface structure formation in germanium by strong field mid IR laser solid interaction at oblique incidence.

    Science.gov (United States)

    Austin, Drake R; Kafka, Kyle R P; Trendafilov, Simeon; Shvets, Gennady; Li, Hui; Yi, Allen Y; Szafruga, Urszula B; Wang, Zhou; Lai, Yu Hang; Blaga, Cosmin I; DiMauro, Louis F; Chowdhury, Enam A

    2015-07-27

    Laser induced periodic surface structures (LIPSS or ripples) were generated on single crystal germanium after irradiation with multiple 3 µm femtosecond laser pulses at a 45° angle of incidence. High and low spatial frequency LIPSS (HSFL and LSFL, respectively) were observed for both s- and p-polarized light. The measured LSFL period for p-polarized light was consistent with the currently established LIPSS origination model of coupling between surface plasmon polaritons (SPP) and the incident laser pulses. A vector model of SPP coupling is introduced to explain the formation of s-polarized LSFL away from the center of the damage spot. Additionally, a new method is proposed to determine the SPP propagation length from the decay in ripple depth. This is used along with the measured LSFL period to estimate the average electron density and Drude collision time of the laser-excited surface. Finally, full-wave electromagnetic simulations are used to corroborate these results while simultaneously offering insight into the nature of LSFL formation.

  2. The efficiency of 'viscous interaction' between the solar wind and the magnetosphere during intense northward IMF events

    Science.gov (United States)

    Tsurutani, Bruce T.; Gonzalez, W. D.

    1995-01-01

    We examined 11 cases when the interplanetary magnetic field (IMF) was intensely northward (greater than 10 nT) for long durations of time (greater than 3 hours), to quantitatively determine an uppler limit on the efficiency of solar wind energy injection into the magnetosphere. We have specifically selected these large B(sub N) events to minimize the effects of magnetic reconnection. Many of these cases occurred during intervals of high-speed streams associated with coronal mass ejections when viscous interaction effects might be at a maximum. It is found that the typical efficiency of solar wind energy injection into the magnetosphere is 1.0 x 10(exp -3) to 4.0 x 10(exp -3), 100 to 30 times less efficient than during periods of intense southward IMFs. Other energy sinks not included in these numbers are discussed. Estimates of their magnitudes are provided.

  3. Role of pre-pulses in the interaction of intense, ultrashort lasers with structured surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rajeev, P.P.; Kahaly, S.; Bagchi, S.; Bose, S.; Kiran, P.P.; Ayyub, P.; Ravindra Kumar, G. [Tata Institute of Fundamental Research, Mumbai (India)

    2006-06-15

    We examine enhanced hard X-ray emission (20 - 200 keV) from plasmas produced on nano-particles coated optically polished copper surface under different prepulse conditions. We observe that enhancement reduces with increasing prepulse intensity. The dynamics of the process is seen to be in the picosecond regime. We attribute this to pre-plasma formation on nano-particles and subsequent modification/destruction of the nano-structure layer before the arrival of the main pulse. It is suggested that high-contrast ultrashort pulses are essential for nano-particles to function as yield enhancer. (authors)

  4. Simulation study of radiation enhancement through an interaction between periodically aligned carbon nanotubes and an intense laser

    Science.gov (United States)

    Taguchi, Toshihiro; Inoue, Masahiko; Antonsen, Thomas

    2012-10-01

    Interaction between ultra-intense laser and solid material has a lot of applications. One is an emission of electromagnetic wave in a wide range of wavelength, which is from THz to X-ray. In order to select the wavelength, one of interesting target materials is single-walled carbon nanotube. Huge number of carbon nanotubes can be grown vertically on a substrate and they can be aligned periodically on the substrate. Once an ultra-intense laser is irradiated on the nanotubes, the strong electric field of the laser forcedly oscillates electrons in each nanotube and they irradiate electromagnetic wave. Waves emitted from periodically aligned nanotubes are expected to interfere each other, and then the amplitude of the output radiation is to be enhanced. In order to analyze such radiation processes from the laser-matter interaction, we have been developing an electromagnetic particle-in-cell (PIC) code including collisional and ionization processes. We will present recent results about an interaction between strong laser and carbon nanotubes analyzed by the PIC code. In the presentation, we will show the radiation spectrum and its enhancement due to the periodic structure.

  5. Applications of the Judd-Ofelt theory to the praseodymium ion in laser solids

    Energy Technology Data Exchange (ETDEWEB)

    Bowlby, B.E.; Di Bartolo, B

    2002-12-15

    The praseodymium ion in its trivalent state is a very good representative of the entire class of rare earth ions and of the complex spectroscopic properties that they exhibit when placed in solid host lattices. The plethora of its radiative transitions, on one hand, demands the intervention of a theory that could explain their absolute and relative intensities, and, on the other hand, provides a good opportunity for the verification of the validity and of the limits of such a theory. We present our data on the spectral characteristics of trivalent praseodymium in a crystal of barium yttrium fluoride and apply the Judd-Ofelt theory to this system. We then examine the problems presented by the application of the Judd-Ofelt theory to the praseodymium ion and the remedies that have been proposed to ameliorate its performance in the somewhat extreme case provided by the spectra of this ion in solids.

  6. Computational strong-field quantum dynamics intense light-matter interactions

    CERN Document Server

    2017-01-01

    This graduate textbook introduces the computational techniques to study ultra-fast quantum dynamics of matter exposed to strong laser fields. Coverage includes methods to propagate wavefunctions according to the time-dependent Schrödinger, Klein-Gordon or Dirac equation, the calculation of typical observables, time-dependent density functional theory, multi-configurational time-dependent Hartree-Fock, time-dependent configuration interaction singles, the strong-field approximation, and the microscopic particle-in-cell approach.

  7. Energy Quantization and Probability Density of Electron in Intense-Field-Atom Interactions

    Institute of Scientific and Technical Information of China (English)

    敖淑艳; 程太旺; 李晓峰; 吴令安; 付盘铭

    2003-01-01

    We find that, due to the quantum correlation between the electron and the field, the electronic energy becomes quantized also, manifesting the particle aspect of light in the electron-light interaction. The probability amplitude of finding electron with a given energy is given by a generalized Bessel function, which can be represented as a coherent superposition of contributions from a few electronic quantum trajectories. This concept is illustrated by comparing the spectral density of the electron with the laser assisted recombination spectrum.

  8. EdiFlow: data-intensive interactive workflows for visual analytics

    OpenAIRE

    Benzaken, Veronique; Fekete, Jean-Daniel; Hémery, Pierre-Luc; Khemiri, Wael; Manolescu, Ioana

    2011-01-01

    International audience; Visual analytics aims at combining interactive data visualization with data analysis tasks. Given the explosion in volume and complexity of scientific data, e.g., associated to biological or physical processes or social networks, visual analytics is called to play an important role in scientific data management. Most visual analytics platforms, however, are memory-based, and are therefore limited in the volume of data handled. Moreover, the integration of each new algo...

  9. Target Surface Area Effects on Hot Electron Dynamics from High Intensity Laser-Plasma Interactions

    Science.gov (United States)

    2016-08-19

    amuch higher peak current of hot electronswhich induced current in parallel wires through strong electric andmagneticfield growth . In theHERCULES shots...interaction. This was consistent with an induced current resulting from the growth and decay of a magnetic field of the form ( ) ( )»B t r I t r...Alternatively, direct current would be expected to scale exponentially , while an expanding plasma could be expected to scale as r1 2. It is of interest to note

  10. Enhanced proton acceleration by intense laser interaction with an inverse cone target

    Science.gov (United States)

    Bake, Muhammad Ali; Aimidula, Aimierding; Xiaerding, Fuerkaiti; Rashidin, Reyima

    2016-08-01

    The generation and control of high-quality proton bunches using focused intense laser pulse on an inverse cone target is investigated with a set of particle-in-cell simulations. The inverse cone is a high atomic number conical frustum with a thin solid top and open base, where the laser impinges onto the top surface directly, not down the open end of the cone. Results are compared with a simple planar target, where the proton angular distribution is very broad because of transverse divergence of the electromagnetic fields behind the target. For a conical target, hot electrons along the cone wall surface induce a transverse focusing sheath field. This field can effectively suppress the spatial spreading of the protons, resulting in a high-quality small-emittance, low-divergence proton beam. A slightly lower proton beam peak energy than that of a conventional planar target was also found.

  11. Positron acceleration by sheath field in ultra-intense laser–solid interactions

    Science.gov (United States)

    Yan, Yonghong; Wu, Yuchi; Chen, Jia; Yu, Minghai; Dong, Kegong; Gu, Yuqiu

    2017-04-01

    A positron production experiment was performed by irradiating an ultra-intense picosecond laser on solid tantalum targets. Quasi-monoenergetic positron beams were obtained owing to the sheath field on the back of the target. The experiment shows that the peak energy of the positron spectrum has a linear relation with the reciprocal of the target diameter. A simple analytical model of the sheath field was constructed to explain the experimental data, which predicts the positron peak energy in terms of the target diameter and hot electron parameters. Based on the field model, Monte Carlo simulations were conducted to treat the positron production and acceleration self-consistently. The simulated spectra are in good agreement with most experiment results. The disagreement of the 1 mm diameter data reveals that the hot electron propagation along the target flank surface plays an important role in the sheath field set up. Several aspects involved in the positron acceleration are discussed.

  12. Dynamics of self-generated, large amplitude magnetic fields following high-intensity laser matter interaction

    CERN Document Server

    Sarri, G; Cecchetti, C A; Kar, S; Liseykina, T V; Yang, X H; Dieckmann, M E; Fuchs, J; Galimberti, M; Gizzi, L A; Jung, R; Kourakis, I; Osterholz, J; Pegoraro, F; Robinson, A P L; Romagnani, L; Willi, O; Borghesi, M

    2012-01-01

    The dynamics of magnetic fields with amplitude of several tens of Megagauss, generated at both sides of a solid target irradiated with a high intensity (? 1019W/cm2) picosecond laser pulse, has been spatially and temporally resolved using a proton imaging technique. The amplitude of the magnetic fields is sufficiently large to have a constraining effect on the radial expansion of the plasma sheath at the target surfaces. These results, supported by numerical simulations and simple analytical modeling, may have implications for ion acceleration driven by the plasma sheath at the rear side of the target as well as for the laboratory study of self-collimated high-energy plasma jets.

  13. Nonlinear interaction of charged particles with nonplane counterpropagating laser pulses of relativistic intensities

    Directory of Open Access Journals (Sweden)

    H. K. Avetissian

    2010-10-01

    Full Text Available The nonlinear threshold phenomena of particle reflection and capture of electrons in the induced Compton process that have previously been revealed in the case of plane monochromatic counterpropagating waves, take place also with the actual nonplane laser pulses of ultrashort duration and lead to particle acceleration. In contrast to analogous phenomena in the induced Cherenkov and undulator processes, the Compton reflection-capture mechanism with laser pulses of relativistic intensities practically may be realized for arbitrary initial energies of particles. The acceleration effect for particles initially in rest is explored numerically, taking into account the significance of this case connected with the relativistic electron bunches of high densities, which currently may be realized by relativistic lasers on the ultrathin solid foils where the electrons initially are almost in rest.

  14. Heat-treated microstructure and mechanical properties of laser solid forming Ti-6Al-4V alloy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shuangyin; LIN Xin; CHEN Jing; HUANG Weidong

    2009-01-01

    The effects of heat treatment on the microstmcture and mechanical properties of laser solid forming (LSF) Ti-6Al-4V alloy were investigated. The influences of the temperature and time of solution treatment and aging treatment were analyzed. The results show that the microstructure of LSFed samples consists of Widmanstatten α laths and a little acicular in columnar prior β grains with an average grain width of 300 which grow epitaxially from the substmte along the deposition direction (Z). Solution treatment had an important effect on the width, aspect ratio, and volume fraction of primary and secondary α laths, and aging treatment mainly affects the aspect ratio and volume fraction of pri-mary α laths and the width and volume fraction of secondary α laths. Globular α phase was first observed in LSFed samples when the sam-ples were heat treated with solution treatment (950℃, 8 h/air cooling (AC)) or with solution treatment (950℃, 1 h/AC) and aging treatment (550℃, above 8 h/AC), respectively. The coarsening and globularization mechanisms of α phase in LSFed Ti-6Al-4V alloy during heat treatment were presented. To obtain good integrated mechanical properties for LSFed Ti-6Al-4V alloys, an optimized heat treatment regimen was suggested.

  15. Mono-energetic ions emission by nanosecond laser solid target irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Muoio, A., E-mail: Annamaria.Muoio@lns.infn.it [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Viale F.S. D’Alcontres 31, 98166 Messina (Italy); Tudisco, S. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Altana, C. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via S. Sofia 64, 95123 Catania (Italy); Lanzalone, G. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Università degli Studi di Enna “Kore”, Via delle Olimpiadi, 94100 Enna (Italy); Mascali, D.; Cirrone, G.A.P.; Schillaci, F. [Istituto Nazionale di Fisica Nucleare – Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Trifirò, A. [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Viale F.S. D’Alcontres 31, 98166 Messina (Italy); Sezione INFN, Catania (Italy)

    2016-09-01

    An experimental campaign aiming to investigate the acceleration mechanisms through laser–matter interaction in nanosecond domain has been carried out at the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS, Catania. Pure Al targets were irradiated by 6 ns laser pulses at different pumping energies, up to 2 J. Advanced diagnostics tools were used to characterize the plasma plume and ion production. We show the preliminary results of this experimental campaign, and especially the ones showing the production of multicharged ions having very narrow energy spreads.

  16. Nonlinear complexity of random visibility graph and Lempel-Ziv on multitype range-intensity interacting financial dynamics

    Science.gov (United States)

    Zhang, Yali; Wang, Jun

    2017-09-01

    In an attempt to investigate the nonlinear complex evolution of financial dynamics, a new financial price model - the multitype range-intensity contact (MRIC) financial model, is developed based on the multitype range-intensity interacting contact system, in which the interaction and transmission of different types of investment attitudes in a stock market are simulated by viruses spreading. Two new random visibility graph (VG) based analyses and Lempel-Ziv complexity (LZC) are applied to study the complex behaviors of return time series and the corresponding random sorted series. The VG method is the complex network theory, and the LZC is a non-parametric measure of complexity reflecting the rate of new pattern generation of a series. In this work, the real stock market indices are considered to be comparatively studied with the simulation data of the proposed model. Further, the numerical empirical study shows the similar complexity behaviors between the model and the real markets, the research confirms that the financial model is reasonable to some extent.

  17. Intensity-based hierarchical clustering in CT-scans: application to interactive segmentation in cardiology

    Science.gov (United States)

    Hadida, Jonathan; Desrosiers, Christian; Duong, Luc

    2011-03-01

    The segmentation of anatomical structures in Computed Tomography Angiography (CTA) is a pre-operative task useful in image guided surgery. Even though very robust and precise methods have been developed to help achieving a reliable segmentation (level sets, active contours, etc), it remains very time consuming both in terms of manual interactions and in terms of computation time. The goal of this study is to present a fast method to find coarse anatomical structures in CTA with few parameters, based on hierarchical clustering. The algorithm is organized as follows: first, a fast non-parametric histogram clustering method is proposed to compute a piecewise constant mask. A second step then indexes all the space-connected regions in the piecewise constant mask. Finally, a hierarchical clustering is achieved to build a graph representing the connections between the various regions in the piecewise constant mask. This step builds up a structural knowledge about the image. Several interactive features for segmentation are presented, for instance association or disassociation of anatomical structures. A comparison with the Mean-Shift algorithm is presented.

  18. Nonlinear interaction of intense hypergeometric Gaussian subfamily laser beams in plasma

    Science.gov (United States)

    Sobhani, H.; Vaziri (Khamedi), M.; Rooholamininejad, H.; Bahrampour, A. R.

    2016-07-01

    Propagation of Hypergeometric-Gaussian laser beam in a nonlinear plasma medium is investigated by considering the Source Dependent Expansion method. A subfamily of Hypergeometric-Gaussian beams with a non-negative, even and integer radial index, can be expressed as the linear superposition of finite number of Laguerre-Gaussian functions. Propagation of Hypergeometric-Gaussian beams in a nonlinear plasma medium depends on the value of radial index. The bright rings' number of these beams is changed during the propagation in plasma medium. The effect of beam vortex charge number l and initial (input) beam intensity on the self-focusing of Hypergeometric-Gaussian beams is explored. Also, by choosing the suitable initial conditions, Hypergeometric-Gaussian subfamily beams can be converted to one or more mode components that a typical of mode conversion may be occurred. The self-focusing of these winding beams can be used to control the focusing force and improve the electron bunch quality in laser plasma accelerators.

  19. Interaction of intense femtosecond laser pulses with KDP and DKDP crystals in the short wavelength regime

    Science.gov (United States)

    Duchateau, Guillaume; Geoffroy, Ghita; Belsky, Andrei; Fedorov, Nikita; Martin, Patrick; Guizard, Stéphane

    2013-10-01

    We investigate the electronic photo-excitation and relaxation mechanisms involved in the optical breakdown of potassium dihydrogen phosphate crystal (KH2PO4) and its deuterated form. The dynamics and spectroscopic properties of electron-hole pair formation are investigated using time-resolved measurement of the dielectric function, and luminescence spectroscopy. The non-common mechanical and electronic characteristics of these dielectric materials are revealed by the particular structure of ablation craters and also by the complex dynamics observed in the relaxation of excited carriers. This relaxation occurs in two steps, and varies with the initial carrier density and thus with the laser intensity. We show that the defect states play a key role in the excitation pathways, and also determine the relaxation stage. The latter also depends upon the initial amount of energy of the electron-hole pair after photo-excitation. A model based on kinetic equations describing the evolution of the different level populations allows us to successfully interpret and reproduce the experimental data.

  20. Delayed conifer mortality after fuel reduction treatments: Interactive effects of fuel, fire intensity, and bark beetles

    Science.gov (United States)

    Youngblood, A.; Grace, J.B.; Mciver, J.D.

    2009-01-01

    turn depended on fire intensity, which was greater in units where thinning increased large woody fuels. These results have implications when deciding among management options for restoring ecosystem health in similar ponderosa pine and Douglas-fir forests. ?? 2009 by the Ecological Society of America.

  1. Interaction of ultra-short ultra-intense laser pulses with under-dense plasmas; Interaction d'impulsions laser ultra-courtes et ultra-intenses avec des plasmas sous denses

    Energy Technology Data Exchange (ETDEWEB)

    Solodov, A

    2000-12-15

    Different aspects of interaction of ultra-short ultra-intense laser pulses with underdense plasmas are studied analytically and numerically. These studies can be interesting for laser-driven electron acceleration in plasma, X-ray lasers, high-order harmonic generation, initial confinement fusion with fast ignition. For numerical simulations a fully-relativistic particle code WAKE was used, developed earlier at Ecole Polytechnique. It was modified during the work on the thesis in the part of simulation of ion motion, test electron motion, diagnostics for the field and plasma. The studies in the thesis cover the problems of photon acceleration in the plasma wake of a short intense laser pulse, phase velocity of the plasma wave in the Self-Modulated Laser Wake-Field Accelerator (SM LWFA), relativistic channeling of laser pulses with duration of the order of a plasma period, ion dynamics in the wake of a short intense laser pulse, plasma wave breaking. Simulation of three experiments on the laser pulse propagation in plasma and electron acceleration were performed. Among the main results of the thesis, it was found that reduction of the plasma wave phase velocity in the SM LWFA is crucial for electron acceleration, only if a plasma channel is used for the laser pulse guiding. Self-similar structures describing relativistic guiding of short laser pulses in plasmas were found and relativistic channeling of initially Gaussian laser pulses of a few plasma periods in duration was demonstrated. It was shown that ponderomotive force of a plasma wake excited by a short laser pulse forms a channel in plasma and plasma wave breaking in the channel was analyzed in detail. Effectiveness of electron acceleration by the laser field and plasma wave was compared and frequency shift of probe laser pulses by the plasma waves was found in conditions relevant to the current experiments. (author)

  2. Radiation from laser-microplasma-waveguide interactions in the ultra-intense regime

    CERN Document Server

    Yi, Longqing; Shen, Baifei

    2016-01-01

    When a high-contrast ultra-relativistic laser beam enters a micro-sized plasma waveguide, the pulse energy is coupled into waveguide modes, which remarkably modifies the interaction of electrons and electromagnetic wave. The electrons that pulled out of walls form a dense helical bunch inside the channel are efficiently accelerated by the transverse magnetic modes to hundreds of MeVs. In the mean time, the asymmetry in the transverse electric and magnetic fields provides significant wiggling that leads to a bright, well-collimated emission of hard X-rays. In this paper, we present our study on the underlying physics in the aforementioned process using 3D particle-in-cell simulations. The mechanism of electron acceleration and the dependence of radiation properties on different laser plasma parameters are addressed. A theoretical analysis model and basic scalings for X-ray emission are also presented by considering the lowest optical modes in the waveguide, which is adequate to describe the basic observed phen...

  3. Interaction of Volcanic Forcing and El Nino: Sensitivity to the Eruption Magnitude and El Nino Intensity

    KAUST Repository

    Predybaylo, Evgeniya

    2015-04-01

    Volcanic aerosols formed in the stratosphere after strong explosive eruptions influence Earth\\'s radiative balance, affecting atmospheric and oceanic temperatures and circulation. It was observed that the recent volcanic eruptions frequently occurred in El Nino years. Analysis of the paleo data confirms that the probability of a sequent El Nino occurrence after the eruption increases. To better understand the physical mechanism of this interaction we employed ocean-atmosphere coupled climate model CM2.1, developed in the Geophysical Fluid Dynamics Laboratory, and conducted a series of numerical experiments using initial conditions with different El Nino Southern Oscillation (ENSO) strengths forced by volcanic eruptions of different magnitudes, Pinatubo of June 1991 and Tambora of April 1815: (i) strong ENSO/Pinatubo, (ii) weak ENSO/Pinatubo, (iii) strong ENSO/Tambora. The amount of ejected material from the Tambora eruption was about three times greater than that of the Pinatubo eruption. The initial conditions with El Nino were sampled from the CM2.1 long control run. Our simulations show the enhancement of El Nino in the second year after an eruption. We found that the spatial-temporal structure of model responses is sensitive to both the magnitude of an eruption and the strength of El Nino. We analyzed the ocean dynamic in the tropical Pacific for all cases to uncover the physical mechanism, resulting in the enhanced and/or prolonged El Nino.

  4. Radiation from laser-microplasma-waveguide interactions in the ultra-intense regime

    Science.gov (United States)

    Yi, Longqing; Pukhov, Alexander; Shen, Baifei

    2016-07-01

    When a high-contrast ultra-relativistic (>1020 W/cm2) laser beam enters a micro-sized plasma waveguide, the pulse energy is coupled into waveguide modes, which significantly modifies the interaction between the electrons and electromagnetic wave. Electrons pulled out from the walls of the waveguide form a dense helical bunch inside the channel and are efficiently accelerated by the transverse magnetic modes to hundreds of MeV. The asymmetry in the transverse electric and magnetic fields drives strong oscillations, which lead to the emission of bright, well-collimated, hard X-rays. In this paper, we present our study on the underlying physics in the aforementioned process using 3D particle-in-cell simulations. The mechanism of electron acceleration and the dependence of radiation properties on different laser plasma parameters are addressed. An analytic model and basic scalings for X-ray emission are also presented by considering the lowest optical modes in the waveguide, which is adequate to describe the basic phenomenon. In addition, the effects of high-order modes as well as laser polarization are also qualitatively discussed. The considered X-ray source has promising features, potentially making it a competitive candidate for a future tabletop synchrotron source.

  5. Role of single-particle and pair condensates in Bose systems with arbitrary intensity of interaction

    Directory of Open Access Journals (Sweden)

    A.S. Peletminskii

    2013-03-01

    Full Text Available We study a superfluid Bose system with single-particle and pair condensates on the basis of a half-phenomenological theory of a Bose liquid not involving the weakness of interparticle interaction. The coupled equations describing the equilibrium state of such system are derived from the variational principle for entropy. These equations are analyzed at zero temperature both analytically and numerically. It is shown that the fraction of particles in the single-particle and pair condensates essentially depends on the total density of the system. At densities attainable in condensates of alkali-metal atoms, almost all particles are in the single-particle condensate. The pair condensate fraction grows with increasing total density and becomes dominant. It is shown that at density of liquid helium, the single-particle condensate fraction is less than 10% that agrees with experimental data on inelastic neutron scattering, Monte Carlo calculations and other theoretical predictions. The ground state energy, pressure, and compressibility are found for the system under consideration. The spectrum of single-particle excitations is also analyzed.

  6. An Overview of Trypanosoma brucei Infections: An Intense Host–Parasite Interaction

    Science.gov (United States)

    Ponte-Sucre, Alicia

    2016-01-01

    Trypanosoma brucei rhodesiense and T. brucei gambiense, the causative agents of Human African Trypanosomiasis, are transmitted by tsetse flies. Within the vector, the parasite undergoes through transformations that prepares it to infect the human host. Sequentially these developmental stages are the replicative procyclic (in which the parasite surface is covered by procyclins) and trypo-epimastigote forms, as well as the non-replicative, infective, metacyclic form that develops in the vector salivary glands. As a pre-adaptation to their life in humans, metacyclic parasites begin to express and be densely covered by the Variant Surface Glycoprotein (VSG). Once the metacyclic form invades the human host the parasite develops into the bloodstream form. Herein the VSG triggers a humoral immune response. To avoid this humoral response, and essential for survival while in the bloodstream, the parasite changes its cover periodically and sheds into the surroundings the expressed VSG, thus evading the consequences of the immune system activation. Additionally, tools comparable to quorum sensing are used by the parasite for the successful parasite transmission from human to insect. On the other hand, the human host promotes clearance of the parasite triggering innate and adaptive immune responses and stimulating cytokine and chemokine secretion. All in all, the host–parasite interaction is extremely active and leads to responses that need multiple control sites to develop appropriately. PMID:28082973

  7. Potential drug-drug interactions in medical intensive care unit of a tertiary care hospital in Pakistan.

    Science.gov (United States)

    Ismail, Mohammad; Khan, Farmanullah; Noor, Sidra; Haider, Iqbal; Haq, Inam-Ul; Ali, Zahid; Shah, Zahir; Hassam, Mohsin

    2016-10-01

    Background Patients admitted to intensive care unit (ICU) present with severe and life-threatening illnesses. Most of them suffer from various comorbidities. They usually receive complex pharmacotherapy with large number of medicines which increase the risk of drug-drug interactions (DDIs). Objective The present report aimed to investigate prevalence and levels of potential DDIs (pDDIs) in medical ICU. Methods Medications profiles of 416 patients were checked for pDDIs using Micromedex Drug-Reax(®). Prevalence, levels of severity and levels of documentation were reported. Results Of total 416 patients, 310 were exposed to pDDIs (overall prevalence = 74.5 %). Likewise, a prevalence rate of 13.9 % was recorded for contraindicated pDDIs, 52.2 % for major pDDI and 58.4 % for moderate pDDI. This study reported 740 interacting drug pairs that were presented in total 1686 pDDIs. Of 1686 pDDIs, 4.3 % were of contraindicated severity, 33.8 % of major severity and 49.6 % of moderate severity, whereas 45.5 % were of fair scientific evidence and 41.4 % of good scientific evidence. Conclusion In this study, pDDIs were found highly prevalent in ICU patients at a rate of 74.5 %. Most of the pDDIs had moderate severity; however, substantial number of interactions (38.1 %) had major and contraindicated severity.

  8. QPROP: A Schrödinger-solver for intense laser atom interaction

    Science.gov (United States)

    Bauer, Dieter; Koval, Peter

    2006-03-01

    The QPROP package is presented. QPROP has been developed to study laser-atom interaction in the nonperturbative regime where nonlinear phenomena such as above-threshold ionization, high order harmonic generation, and dynamic stabilization are known to occur. In the nonrelativistic regime and within the single active electron approximation, these phenomena can be studied with QPROP in the most rigorous way by solving the time-dependent Schrödinger equation in three spatial dimensions. Because QPROP is optimized for the study of quantum systems that are spherically symmetric in their initial, unperturbed configuration, all wavefunctions are expanded in spherical harmonics. Time-propagation of the wavefunctions is performed using a split-operator approach. Photoelectron spectra are calculated employing a window-operator technique. Besides the solution of the time-dependent Schrödinger equation in single active electron approximation, QPROP allows to study many-electron systems via the solution of the time-dependent Kohn-Sham equations. Program summaryProgram title:QPROP Catalogue number:ADXB Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXB Program obtainable from:CPC Program Library, Queen's University of Belfast, N. Ireland Computer on which program has been tested:PC Pentium IV, Athlon Operating system:Linux Program language used:C++ Memory required to execute with typical data:Memory requirements depend on the number of propagated orbitals and on the size of the orbitals. For instance, time-propagation of a hydrogenic wavefunction in the perturbative regime requires about 64 KB RAM (4 radial orbitals with 1000 grid points). Propagation in the strongly nonperturbative regime providing energy spectra up to high energies may need 60 radial orbitals, each with 30000 grid points, i.e. about 30 MB. Examples are given in the article. No. of bits in a word:Real and complex valued numbers of double precision are used No. of lines in distributed program

  9. Detailed Experimental Study of Ion Acceleration by Interaction of an Ultra-Short Intense Laser with an Underdense Plasma.

    Science.gov (United States)

    Kahaly, S; Sylla, F; Lifschitz, A; Flacco, A; Veltcheva, M; Malka, V

    2016-08-17

    Ion acceleration from intense (Iλ(2) > 10(18) Wcm(-2) μm(2)) laser-plasma interaction is experimentally studied within a wide range of He gas densities. Focusing an ultrashort pulse (duration  ion plasma period) on a newly designed submillimetric gas jet system, enabled us to inhibit total evacuation of electrons from the central propagation channel reducing the radial ion acceleration associated with ponderomotive Coulomb explosion, a mechanism predominant in the long pulse scenario. New ion acceleration mechanism have been unveiled in this regime leading to non-Maxwellian quasi monoenergetic features in the ion energy spectra. The emitted nonthermal ion bunches show a new scaling of the ion peak energy with plasma density. The scaling identified in this new regime differs from previously reported studies.

  10. Laser-driven γ-ray, positron, and neutron source from ultra-intense laser-matter interactions

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Tatsufumi, E-mail: t-nakamura@fit.ac.jp [Fukuoka Institute of Technology, Fukuoka, Fukuoka 811-0295 (Japan); Hayakawa, Takehito [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1106 (Japan)

    2015-08-15

    In ultra-intense laser-matter interactions, γ-rays are effectively generated via the radiation reaction effect. Since a significant fraction of the laser energy is converted into γ-rays, understanding of the energy transport inside of the target is important. We have developed a Particle-in-Cell code which includes generation of the γ-rays, their energy transport, and photo-nuclear reactions. Using the code, we have investigated the characteristics of the quantum beams generated by the transport of the laser-driven γ-rays. It is shown that collimated, mono-energetic positron beams with hundreds of MeV are generated by using thick targets. Neutron beams are also effectively generated by using beryllium targets via photo-nuclear reactions. These lead to the proposal of quantum beam sources of γ-rays, positrons, and neutrons with distinctive characters, which are selectively generated by choosing target conditions.

  11. Effect of plasma inhomogeneity on ion acceleration when an ultra-intense laser pulse interacts with a foil target

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, A.A.; Platonov, K.Yu. [Institute for Laser Physics, SC Vavilov State Optical Institute, St. Petersburg (Russian Federation); Zhidkov, A.G. [University of Tokyo, Graduate School of Engineering, Nuclear Engineering Research Laboratory, Tokai, Naka, Ibaraki (Japan); Sasaki, A. [Advanced Photon Research Center JAERI, Kizu-cho, Soraku-gun, Kyoto (Japan)

    2002-07-01

    Fast electrons generated via the interaction of ultra-intense laser pulses with a solid target can produce multi-MeV ions from laser-induced plasmas. These fast ions can be used for various applications ranging from the ion implantation to the stimulation of nuclear reactions. The most important point here is the efficiency of production of such fast ions. We analyse in detail, with the help of an analytical model and particle-in-cell simulations, the most efficient acceleration mechanisms including the ponderomotive force driving and acceleration by the shock wave, and compare the electrostatic ion acceleration at the front side and at the rear side of a foil target. We also determine the optimal plasma density distribution shaped by the laser pre-pulse. (author)

  12. Effect of low intensity laser interaction with human skin fibroblast cells using fiber-optic nano-probes.

    Science.gov (United States)

    Pal, Gopalendu; Dutta, Ashim; Mitra, Kunal; Grace, Michael S; Amat, Albert; Romanczyk, Tara B; Wu, Xingjia; Chakrabarti, Kristi; Anders, Juanita; Gorman, Erik; Waynant, Ronald W; Tata, Darrell B

    2007-03-01

    Over the past forty years, many efforts have been devoted to study low power laser light interactions with biological systems. Some of the investigations were performed in-vitro, on bulk cell populations. Our present work was undertaken to apply specially engineered fiber-optic based nano-probes for the precise delivery of laser light on to a single cell and to observe production of low power laser light induced reactive oxygen species (ROS). A normal human skin fibroblast (NHF) cell line was utilized in this investigation and the cells were irradiated under two different schemes of exposure: (1) an entire NHF cell population within a Petri dish using a fan beam methodology, and (2) through the precise delivery of laser energy on to a single NHF cell using fiber-optic nano-probe. Photobiostimulative studies were conducted through variation of laser intensity, exposure time, and the energy dose of exposure. Laser irradiation induced enhancement in the rate of cell proliferation was observed to be dependent on laser exposure parameters and the method of laser delivery. The total energy dose (fluence) had a greater influence on the enhancement in the rate of cellular proliferation than compared to laser intensity. The enhancement in the growth rate was observed to have a finite life-time of several days after the initial laser exposure. Fluorescent life-time imaging of ROS was performed during the nano-based single cell exposure method. The kinetics of ROS generation was found to depend strongly on the laser fluence and not on the laser intensity.

  13. Intense Flare-CME Event of the Year 2015: Propagation and Interaction Effects between Sun and Earth's Orbit

    CERN Document Server

    Johri, Abhishek

    2016-01-01

    In this paper, We report the interplanetary effects of a fast coronal mass ejection (CME) associated with the intense X2.7 flare that occurred on 05 May 2015. The near-Sun signatures of the CME at low-coronal heights $<$2 {R$_{\\odot}$} are obtained from the EUV images at 171 {\\AA} and metric radio observations. The intensity and duration of the CME-driven radio bursts in the near-Sun and interplanetary medium indicate this CME event to be an energetic one. The interplanetary scintillation data, along with the low-frequency radio spectrum, played a crucial role in understanding the radial evolution of the speed and expansion of the CME in the inner heliosphere as well as its interaction with a preceding slow CME. The estimation of the speed of the CME at several points along the Sun to 1 AU shows shows that i) the CME went through a rapid acceleration as well as expansion up to a height of $\\approx$6 {R$_{\\odot}$}, and ii) the CME continued to propagate at speed $\\geq$800 kms$^{-1}$ between the Sun and 1 AU...

  14. Feasibility and observed safety of interactive video games for physical rehabilitation in the intensive care unit: a case series.

    Science.gov (United States)

    Kho, Michelle E; Damluji, Abdulla; Zanni, Jennifer M; Needham, Dale M

    2012-04-01

    Early rehabilitation in the intensive care unit (ICU) improves patients' physical function. Despite reports of using commercially available interactive video game systems for rehabilitation, there are few data evaluating feasibility and safety as part of routine in-patient rehabilitation, particularly in the ICU. We conducted an observational study from September 1, 2009, to August 31, 2010, of adults admitted to a 16-bed medical ICU receiving video games as part of routine physical therapy (PT), evaluating use and indications and occurrence of 14 prospectively monitored safety events. Of 410 patients receiving PT in the medical ICU, 22 (5% of all patients; male, 64%; median age, 52 years) had 42 PT treatments with video games (median [interquartile range] per patient, 1.0 [1.0-2.0]). Main indications for video game therapy included balance (52%) and endurance (45%), and the most common activities included boxing (38%), bowling (24%), and balance board (21%). Of 42 treatments, 69% occurred while standing and 45% while mechanically ventilated. During 35 hours of PT treatment, 0 safety events occurred (95% upper confidence limit for safety event rate, 8.4%). Novel use of interactive video games as part of routine PT in critically ill patients is feasible and appears safe in our case series. Video game therapy may complement existing rehabilitation techniques for ICU patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Theoretical study of the interaction between intense laser pulses and rare gas clusters; Etude theorique de l'interaction entre une impulsion laser intense et un agregat de gaz rare

    Energy Technology Data Exchange (ETDEWEB)

    Micheau, S

    2007-07-15

    The irradiation of nanometer-scale rare gas clusters by a short (a few hundreds of femtosecond) and intense (I > 10{sup 15} W/cm{sup 2}) laser pulse yields multi-keV short X-ray bursts. We employ an hydrodynamic model, the so-called 'nano-plasma model', to understand the mechanisms that tailor the interaction. In this model, the cluster is treated as a dielectric sphere embedded in the quasi-static laser field leading to the formation of a plasma of nano-metric size. We have shown that this model cannot reproduce the experimental results such as the high ionization states and associated X-ray spectra. We have thus included in the model two additional mechanisms that significantly improve the ionization dynamics. First, we have introduced high order ionization processes involving intermediate excited states X{sup q+} + e{sup -} {yields} X{sup q+*} + e{sup -} {yields}... {yields} X{sup q+1+} + 2 e{sup -}. We have used a model potential approach to describe the electronic structure of the cluster's ions (and atoms), and we have computed the total excitation and ionization cross-sections in the distorted-wave Born approximation. Secondly we have studied the influence of screening phenomena induced by the electronic density on the interaction dynamics. By using a sophisticated potential, we have shown that screening effects enhance ionization and lower excitation cross sections with respect to the unscreened data. The improved nano-plasma model allows us to reproduce the populations of highly charged states experimentally observed, and the variation of argon He{sub {alpha}} emission with respect to the various experimental parameters (cluster size, laser pulse duration, intensity and wavelength). We have further computed time- and energy-resolved X-ray spectra which emphasize ultra-short emission duration (less than 100 fs), and therefore indicate that cluster-based X-ray sources are adequate to ultrafast X-ray science applications. (author)

  16. Evaluation of Transmutation of 137Cs(r,n) 136Cs Using Ultra-Intense Lasers in Solid Targets

    Institute of Scientific and Technical Information of China (English)

    R. Sadighi-Bonabi; O. Kokabee

    2006-01-01

    Relativistic electrons produced in ultra-intense laser-solid interaction generate highly collimated γ-ray beams through Bremsstrahlung that can be used to induce photonuclear reactions. Photonuclear transmutation (of (γ, n) type) of 137Cs, one of the hazardous nuclear wastes with half-life of 30.17 years which cannot be transmuted practically with neutron bombardment due to its very low neutron capture cross section, has been considered. Nuclear activity of produced 136Cs with half-life of 13.16 days has been evaluated analytically using available experimental data. With irradiating a 137Cs sample by p-polarized laser light of 1020 Wcm-2 and the repetition rate of 10 Hz for 30mm, the activity of 0.24 Bq is obtained. It is found that intensity has a large effect in yield around 1021 Wcm-2. For similar laser with intensity of 5×1021 Wcm-2, the activity increases with a factor of 105.

  17. Accelerating Protons to Therapeutic Energies with Ultra-Intense Ultra-Clean and Ultra-Short Laser Pulses

    CERN Document Server

    Bulanov, Stepan S; Bychenkov, Valery Yu; Chvykov, Vladimir; Kalinchenko, Galina; Matsuoka, Takeshi; Rousseau, Pascal; Reed, Stephen; Yanovsky, Victor; Krushelnick, Karl; Litzenberg, Dale William; Maksimchuk, Anatoly

    2008-01-01

    Proton acceleration by high-intensity laser pulses from ultra-thin foils for hadron therapy is discussed. With the improvement of the laser intensity contrast ratio to 10-11 achieved on Hercules laser at the University of Michigan, it became possible to attain laser-solid interactions at intensities up to 1022 W/cm2 that allows an efficient regime of laser-driven ion acceleration from submicron foils. Particle-In-Cell (PIC) computer simulations of proton acceleration in the Directed Coulomb explosion regime from ultra-thin double-layer (heavy ions / light ions) foils of different thicknesses were performed under the anticipated experimental conditions for Hercules laser with pulse energies from 3 to 15 J, pulse duration of 30 fs at full width half maximum (FWHM), focused to a spot size of 0.8 microns (FWHM). In this regime heavy ions expand predominantly in the direction of laser pulse propagation enhancing the longitudinal charge separation electric field that accelerates light ions. The dependence of the ma...

  18. Interactive influence of leaf age, light intensity, and girdling on green ash foliar chemistry and emerald ash borer development.

    Science.gov (United States)

    Chen, Yigen; Poland, Therese M

    2009-07-01

    Biotic and abiotic environmental factors affect plant nutritional quality and defensive compounds that confer plant resistance to herbivory. Influence of leaf age, light availability, and girdling on foliar nutrition and defense of green ash (Fraxinus pennsylvanica Marsh) was examined in this study. Longevity of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), adults reared on green ash foliage subjected to these factors was assayed. Mature leaves generally were more nutritious with greater amino acids and a greater ratio of protein to non-structural carbohydrate (P:C) than young leaves, in particular when trees were grown in shade. On the other hand, mature leaves had lower amounts of trypsin and chymotrypsin inhibitors, and total phenolics compared to young leaves. Lower defense of mature leaves alone, or along with higher nutritional quality may lead to increased survival and longevity of emerald ash borer feeding on mature leaves. Sunlight reduced amino acids and P:C ratio, irrespective of leaf age and girdling, and elevated total protein of young foliage, but not protein of mature leaves. Sunlight also dramatically increased all investigated defensive compounds of young, but not mature leaves. Girdling reduced green ash foliar nutrition, especially, of young leaves grown in shade and of mature leaves grown in sun. However emerald ash borer performance did not differ when fed leaves from trees grown in sun or shade, or from girdled or control trees. One explanation is that emerald ash borer reared on lower nutritional quality food may compensate for nutrient deficiency by increasing its consumption rate. The strong interactions among leaf age, light intensity, and girdling on nutrition and defense highlight the need for caution when interpreting data without considering possible interactions.

  19. Scales of benthic–pelagic coupling and the intensity of species interactions: From recruitment limitation to top-down control

    Science.gov (United States)

    Navarrete, Sergio A.; Wieters, Evie A.; Broitman, Bernardo R.; Castilla, Juan Carlos

    2005-01-01

    Large and usually unpredictable variation in species interaction strength has been a major roadblock to applying local experimental results to large-scale management and conservation issues. Recent studies explicitly considering benthic-pelagic coupling are starting to shed light on, and find regularities in, the causes of such large-scale variation in coastal ecosystems. Here, we evaluate the effects of variation in wind-driven upwelling on community regulation along 900 km of coastline of the southeastern Pacific, between 29°S and 35°S during 72 months. Variability in the intensity of upwelling occurring over tens of km produced predictable variation in recruitment of intertidal mussels, but not barnacles, and did not affect patterns of community structure. In contrast, sharp discontinuities in upwelling regimes produced abrupt and persistent breaks in the dynamics of benthic and pelagic communities over hundreds of km (regional) scales. Rates of mussel and barnacle recruitment changed sharply at ≈32°-33°S, determining a geographic break in adult abundance of these competitively dominant species. Analysis of satellite images demonstrates that regional-scale discontinuities in oceanographic regimes can couple benthic and pelagic systems, as evidenced by coincident breaks in dynamics and concentration of offshore surface chlorophyll-a. Field experiments showed that the paradigm of top-down control of intertidal benthic communities holds only south of the discontinuity. To the north, populations seem recruitment-limited, and predators have negligible effects, despite attaining similarly high abundances and potential predation effects across the region. Thus, geographically discontinuous oceanographic regimes set bounds to the strength of species interactions and define distinct regions for the design and implementation of sustainable management and conservation policies. PMID:16332959

  20. Scales of benthic-pelagic coupling and the intensity of species interactions: from recruitment limitation to top-down control.

    Science.gov (United States)

    Navarrete, Sergio A; Wieters, Evie A; Broitman, Bernardo R; Castilla, Juan Carlos

    2005-12-13

    Large and usually unpredictable variation in species interaction strength has been a major roadblock to applying local experimental results to large-scale management and conservation issues. Recent studies explicitly considering benthic-pelagic coupling are starting to shed light on, and find regularities in, the causes of such large-scale variation in coastal ecosystems. Here, we evaluate the effects of variation in wind-driven upwelling on community regulation along 900 km of coastline of the southeastern Pacific, between 29 degrees S and 35 degrees S during 72 months. Variability in the intensity of upwelling occurring over tens of km produced predictable variation in recruitment of intertidal mussels, but not barnacles, and did not affect patterns of community structure. In contrast, sharp discontinuities in upwelling regimes produced abrupt and persistent breaks in the dynamics of benthic and pelagic communities over hundreds of km (regional) scales. Rates of mussel and barnacle recruitment changed sharply at approximately 32 degrees -33 degrees S, determining a geographic break in adult abundance of these competitively dominant species. Analysis of satellite images demonstrates that regional-scale discontinuities in oceanographic regimes can couple benthic and pelagic systems, as evidenced by coincident breaks in dynamics and concentration of offshore surface chlorophyll-a. Field experiments showed that the paradigm of top-down control of intertidal benthic communities holds only south of the discontinuity. To the north, populations seem recruitment-limited, and predators have negligible effects, despite attaining similarly high abundances and potential predation effects across the region. Thus, geographically discontinuous oceanographic regimes set bounds to the strength of species interactions and define distinct regions for the design and implementation of sustainable management and conservation policies.

  1. Spouse criticism and hostility during marital interaction: effects on pain intensity and behaviors among individuals with chronic low back pain.

    Science.gov (United States)

    Burns, John W; Post, Kristina M; Smith, David A; Porter, Laura S; Buvanendran, Asokumar; Fras, Anne Marie; Keefe, Francis J

    2017-08-08

    Individuals with chronic pain may experience negative responses from spouse, family and friends. Responses such as overt criticism and hostility may be associated with worsening pain and function for chronic pain sufferers. We used a laboratory procedure to evaluate whether variability in spouse criticism/hostility exhibited toward chronic low back pain (CLBP) patients during a conflictual discussion predicted variability in patient pain and function during a subsequent pain-induction task. CLBP patients (n=71) and their spouses (n=71) participated in a 10-minute discussion followed by the patient undergoing a 10-minute structured pain behavior task (SPBT). Spouse criticism/hostility perceived by patients and patient Beck Depression Inventory II (BDI) scores correlated significantly and positively with pain intensity during the SPBT, whereas perceived spouse hostility, patient BDI scores and spouse trait hostility correlated significantly and positively with observed pain behaviors during the SPBT. Spouse criticism/hostility coded by raters from video recordings interacted significantly with patient BDI scores, such that observed spouse criticism/hostility was related significantly and positively with pain behaviors only for patients with high BDI scores. Patient sex interacted significantly with observed spouse criticism/hostility, such that observed spouse criticism/hostility was related significantly and positively with pain behaviors only for female patients. Results support the hypothesis that spouse criticism and hostility - actually expressed or perceived -- may worsen CLBP patient symptoms. Further, women patients and patients high in depressive symptoms appeared most vulnerable to spouse criticism/hostility. Thus, negative marital communication patterns may be appropriate targets for intervention, especially among these two at risk groups.

  2. Communication strategies and intensive interaction therapy meet the theology of the body: bioethics in dialogue with people with profound disabilities.

    Science.gov (United States)

    Matthews, Pia

    2013-01-01

    Academic bioethics does not appear to be interested in communication and its ethical concerns unless communication is to do with issues such as capacity, consent, truth telling and confidentiality. In contrast practitioners are interested in actually communicating with their patients and they are often particularly perplexed when it comes to people with profound disabilities where communication appears disrupted. Although some new and not so new communication strategies, and especially intensive interaction, are available, little has been written on either the ethical concerns these may present or the deeper concepts that underpin them. This article explores the practical applications of some of these communication strategies. By engaging these strategies with theology, and specifically Pope John Paul's Theology of the Body, this article identifies and addresses some significant ethical issues that may arise, notably the risk of dualism and of objectifying the human person. Moreover it provides communication strategies with a rationale that goes beyond practicalities to one based on respect for human dignity, justice and solidarity.

  3. Land-use intensity and host plant identity interactively shape communities of arbuscular mycorrhizal fungi in roots of grassland plants.

    Science.gov (United States)

    Vályi, Kriszta; Rillig, Matthias C; Hempel, Stefan

    2015-03-01

    We studied the effect of host plant identity and land-use intensity (LUI) on arbuscular mycorrhizal fungi (AMF, Glomeromycota) communities in roots of grassland plants. These are relevant factors for intraradical AMF communities in temperate grasslands, which are habitats where AMF are present in high abundance and diversity. In order to focus on fungi that directly interact with the plant at the time, we investigated root-colonizing communities. Our study sites represent an LUI gradient with different combinations of grazing, mowing, and fertilization. We used massively parallel multitag pyrosequencing to investigate AMF communities in a large number of root samples, while being able to track the identity of the host. We showed that host plants significantly differed in AMF community composition, while land use modified this effect in a plant species-specific manner. Communities in medium and low land-use sites were subsets of high land-use communities, suggesting a differential effect of land use on the dispersal of AMF species with different abundances and competitive abilities. We demonstrate that in these grasslands, there is a small group of highly abundant, generalist fungi which represent the dominating species in the AMF community.

  4. Superhot-X-ray and -electron transport in high-intensity CO2-laser-plasma interactions

    Science.gov (United States)

    Enright, G. D.; Burnett, N. H.

    1985-12-01

    A comprehensive investigation of the high-energy (70-400-keV) X-ray emission from CO2 laser-produced plasmas at intensities up to 3 x 10 to the 14th W/sq cm has revealed the presence of a 'superhot' component. The intensity of this component scales very strongly with incident laser intensity. It is expected that for intensities greater than about 5 x 10 to the 15th W/sq cm energy balance in CO2-laser-produced plasmas would be dominated by the energetic electrons responsible for this high-energy X-ray emission.

  5. Echocardiography practice, training and accreditation in the intensive care: document for the World Interactive Network Focused on Critical Ultrasound (WINFOCUS

    Directory of Open Access Journals (Sweden)

    Catena Emanuele

    2008-10-01

    Full Text Available Abstract Echocardiography is increasingly used in the management of the critically ill patient as a non-invasive diagnostic and monitoring tool. Whilst in few countries specialized national training schemes for intensive care unit (ICU echocardiography have been developed, specific guidelines for ICU physicians wishing to incorporate echocardiography into their clinical practice are lacking. Further, existing echocardiography accreditation does not reflect the requirements of the ICU practitioner. The WINFOCUS (World Interactive Network Focused On Critical UltraSound ECHO-ICU Group drew up a document aimed at providing guidance to individual physicians, trainers and the relevant societies of the requirements for the development of skills in echocardiography in the ICU setting. The document is based on recommendations published by the Royal College of Radiologists, British Society of Echocardiography, European Association of Echocardiography and American Society of Echocardiography, together with international input from established practitioners of ICU echocardiography. The recommendations contained in this document are concerned with theoretical basis of ultrasonography, the practical aspects of building an ICU-based echocardiography service as well as the key components of standard adult TTE and TEE studies to be performed on the ICU. Specific issues regarding echocardiography in different ICU clinical scenarios are then described. Obtaining competence in ICU echocardiography may be achieved in different ways – either through completion of an appropriate fellowship/training scheme, or, where not available, via a staged approach designed to train the practitioner to a level at which they can achieve accreditation. Here, peri-resuscitation focused echocardiography represents the entry level – obtainable through established courses followed by mentored practice. Next, a competence-based modular training programme is proposed: theoretical

  6. Relationship between solar wind corotating interaction regions and the phasing and intensity of Saturn kilometric radiation bursts

    Directory of Open Access Journals (Sweden)

    S. V. Badman

    2008-11-01

    Full Text Available Voyager spacecraft measurements of Saturn kilometric radiation (SKR identified two features of these radio emissions: that they pulse at a period close to the planetary rotation period, and that the emitted intensity is correlated with the solar wind dynamic pressure (Desch and Kaiser, 1981; Desch, 1982; Desch and Rucker, 1983. In this study the inter-relation between the intensity and the pulsing of the SKR is analysed using Cassini spacecraft measurements of the interplanetary medium and SKR over the interval encompassing Cassini's approach to Saturn, and the first extended orbit. Cassini Plasma Spectrometer ion data were only available for a subset of the dates of interest, so the interplanetary conditions were studied primarily using the near-continuously available magnetic field data, augmented by the ion moment data when available. Intense SKR bursts were identified when solar wind compressions arrived at Saturn. The intensity of subsequent emissions detected by Cassini during the compression intervals was variable, sometimes remaining intense for several planetary rotations, sometimes dimming and rarely disappearing. The timings of the initial intense SKR peaks were sometimes independent of the long-term pulsing behaviour identified in the SKR data. Overall, however, the pulsing of the SKR peaks during the disturbed intervals was not significantly altered relative to that during non-compression intervals.

  7. Spectroscopic study of the interaction of Nd{sup +3} with amino acids: phenomenological 4f-4f intensity parameters

    Energy Technology Data Exchange (ETDEWEB)

    Jerico, Soraya; Carubelli, Celia R.; Massabni, Ana M.G.; Stucchi, Elizabeth B.; Leite, Sergio R. de A. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica; Malta, Oscar [Pernambuco Univ., Recife, PE (Brazil). Dept. de Quimica Fundamental

    1998-10-01

    We have studied behaviour of the phenomenological 4f-4f intensity parameters in compounds of the Nd{sup 3+} ion with glycine, L-aspartic acid, L-glutamic acid, L-histidine, DL-malic acid and Aspartame{sup TM} in aqueous solution, as function of the pK values and partial charges on the oxygens of the carboxylate groups of these molecules. The results are discussed and qualitatively interpreted in terms of the forced electric dipole and dynamic coupling mechanisms of the 4f-4f intensities, thus indicating that the forced electric dipole mechanism is dominant. (author)

  8. Identifying the source of super-high energetic electrons in the presence of pre-plasma in laser-matter interaction at relativistic intensities

    Science.gov (United States)

    Wu, D.; Krasheninnikov, S. I.; Luan, S. X.; Yu, W.

    2017-01-01

    The generation of super-high energetic electrons influenced by pre-plasma in relativistic intensity laser-matter interaction is studied in a one-dimensional slab approximation with particle-in-cell simulations. Different pre-plasma scale lengths and laser intensities are considered, showing an increase in both particle number and cut-off kinetic energy of electrons with the increase of pre-plasma scale length and laser intensity, the cut-off kinetic energy greatly exceeding the corresponding laser ponderomotive energy. A two-stage electron acceleration model is proposed to explain the underlying physics. The first stage is attributed to the synergetic acceleration by longitudinal electric field and counter-propagating laser pulses, and a scaling law is obtained with efficiency depending on the pre-plasma scale length and laser intensity. These electrons pre-accelerated in the first stage could build up an intense electrostatic potential barrier with maximal value several times as large as the initial electron kinetic energy. Some of the energetic electrons could be further accelerated by reflection off the electrostatic potential barrier, with their finial kinetic energies significantly higher than the values pre-accelerated in the first stage.

  9. Double ionization effect in electron accelerations by high-intensity laser pulse interaction with a neutral gas

    Science.gov (United States)

    Nandan Gupta, Devki

    2013-11-01

    We study the effect of laser-induced double-ionization of a helium gas (with inhomogeneous density profile) on vacuum electron acceleration. For enough laser intensity, helium gas can be found doubly ionized and it strengthens the divergence of the pulse. The double ionization of helium gas can defocus the laser pulse significantly, and electrons are accelerated by the front of the laser pulse in vacuum and then decelerated by the defocused trail part of the laser pulse. It is observed that the electrons experience a very low laser-intensity at the trailing part of the laser pulse. Hence, there is not much electron deceleration at the trailing part of the pulse. We found that the inhomogeneity of the neutral gas reduced the rate of tunnel ionization causing less defocusing of the laser pulse and thus the electron energy gain is reduced.

  10. Double ionization effect in electron accelerations by high-intensity laser pulse interaction with a neutral gas

    Directory of Open Access Journals (Sweden)

    Gupta Devki Nandan

    2013-11-01

    Full Text Available We study the effect of laser-induced double-ionization of a helium gas (with inhomogeneous density profile on vacuum electron acceleration. For enough laser intensity, helium gas can be found doubly ionized and it strengthens the divergence of the pulse. The double ionization of helium gas can defocus the laser pulse significantly, and electrons are accelerated by the front of the laser pulse in vacuum and then decelerated by the defocused trail part of the laser pulse. It is observed that the electrons experience a very low laser-intensity at the trailing part of the laser pulse. Hence, there is not much electron deceleration at the trailing part of the pulse. We found that the inhomogeneity of the neutral gas reduced the rate of tunnel ionization causing less defocusing of the laser pulse and thus the electron energy gain is reduced.

  11. Influence of intensity and frequency of ultrasonic waves on capillary interaction and oil recovery from different rock types.

    Science.gov (United States)

    Naderi, Khosrow; Babadagli, Tayfun

    2010-03-01

    Oil saturated cylindrical sandstone cores were placed into imbibition cells where they contacted with an aqueous phase and oil recovery performances were tested with and without ultrasonic radiation keeping all other conditions and parameters constant. Experiments were conducted for different initial water saturation, oil viscosity and wettability. The specifications of acoustic sources such as ultrasonic intensity (45-84W/sqcm) and frequency (22 and 40kHz) were also changed. An increase in recovery was observed with ultrasonic energy in all cases. This change was more remarkable for the oil-wet medium. The additional recovery with ultrasonic energy became lower as the oil viscosity increased. We also designed a setup to measure the ultrasonic energy penetration capacity in different media, namely air, water, and slurry (sand+water mixture). A one-meter long water or slurry filled medium was prepared and the ultrasonic intensity and frequency were monitored as a function of distance from the source. The imbibition cells were placed at certain distances from the sources and the oil recovery was recorded. Then, the imbibition recovery was related to the ultrasonic intensity, frequency, and distance from the ultrasonic source.

  12. The effect of external magnetic field on the density distributions and electromagnetic fields in the interaction of high-intensity short laser pulse with collisionless underdense plasma

    Science.gov (United States)

    Mahmoodi-Darian, Masoomeh; Ettehadi-Abari, Mehdi; Sedaghat, Mahsa

    2016-03-01

    Laser absorption in the interaction between ultra-intense femtosecond laser and solid density plasma is studied theoretically here in the intensity range I{λ^2} ˜eq 10^{14}{-}10^{16}{{W}}{{{cm}}^{-2}} \\upmu{{{m}}2} . The collisionless effect is found to be significant when the incident laser intensity is less than 10^{16}{{W}}{{{cm}}^{-2}}\\upmu{{{m}}2} . In the current work, the propagation of a high-frequency electromagnetic wave, for underdense collisionless plasma in the presence of an external magnetic field is investigated. When a constant magnetic field parallel to the laser pulse propagation direction is applied, the electrons rotate along the magnetic field lines and generate the electromagnetic part in the wake with a nonzero group velocity. Here, by considering the ponderomotive force in attendance of the external magnetic field and assuming the isothermal collisionless plasma, the nonlinear permittivity of the plasma medium is obtained and the equation of electromagnetic wave propagation in plasma is solved. Here, by considering the effect of the ponderomotive force in isothermal collisionless magnetized plasma, it is shown that by increasing the laser pulse intensity, the electrons density profile leads to steepening and the electron bunches of plasma become narrower. Moreover, it is found that the wavelength of electric and magnetic field oscillations increases by increasing the external magnetic field and the density distribution of electrons also grows in comparison to the unmagnetized collisionless plasma.

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

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Dale Robert (Mission Research Corporation, Albuquerque, NM); MacFarlane, Joseph John (Prism Computational Sciences, Madison, WI); Mehlhorn, Thomas Alan; Campbell, Robert B.

    2004-11-01

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

  14. Recent development of self-interaction-free time-dependent density-functional theory for nonperturbative treatment of atomic and molecular multiphoton processes in intense laser fields.

    Science.gov (United States)

    Chu, Shih-I

    2005-08-08

    In this paper, we present a short account of some recent developments of self-interaction-free density-functional theory (DFT) and time-dependent density-functional theory (TDDFT) for accurate and efficient treatment of the electronic structure, and time-dependent quantum dynamics of many-electron atomic and molecular systems. The conventional DFT calculations using approximate and explicit exchange-correlation energy functional contain spurious self-interaction energy and improper long-range asymptotic potential, preventing reliable treatment of the excited, resonance, and continuum states. We survey some recent developments of DFT/TDDFT with optimized effective potential (OEP) and self-interaction correction (SIC) for both atomic and molecular systems for overcoming some of the above mentioned difficulties. These DFT (TDDFT)/OEP-SIC approaches allow the use of orbital-independent single-particle local potential which is self-interaction free. In addition we discuss several numerical techniques recently developed for efficient and high-precision treatment of the self-interaction-free DFT/TDDFT equations. The usefulness of these procedures is illustrated by a few case studies of atomic, molecular, and condensed matter processes of current interests, including (a) autoionizing resonances, (b) relativistic OEP-SIC treatment of atomic structure (Z=2-106), (c) shell-filling electronic structure in quantum dots, (d) atomic and molecular processes in intense laser fields, including multiphoton ionization, and very-high-order harmonic generation, etc. For the time-dependent processes, an alternative Floquet formulation of TDDFT is introduced for time-independent treatment of multiphoton processes in intense periodic or quasiperiodic fields. We conclude this paper with some open questions and perspectives of TDDFT.

  15. On extreme field limits in high power laser matter interactions: radiation dominant regimes in high intensity electromagnetic wave interaction with electrons

    CERN Document Server

    Bulanov, Sergei V; Kando, Masaki; Koga, James K; Nakamura, Tatsufumi; Bulanov, Stepan S; Zhidkov, Alexei G; Kato, Yoshiaki; Korn, Georg

    2013-01-01

    We discuss the key important regimes of electromagnetic field interaction with charged particles. Main attention is paid to the nonlinear Thomson/Compton scattering regime with the radiation friction and quantum electrodynamics effects taken into account. This process opens a channel of high efficiency electromagnetic energy conversion into hard electromagnetic radiation in the form of ultra short high power gamma ray flashes.

  16. Using an intense laser beam in interaction with muon/electron beam to probe the Noncommutative QED

    CERN Document Server

    Tizchang, S; Haghighat, M; Mohammadi, R

    2016-01-01

    It is known that the linearly polarized photons can partly transform to circularly polarized ones via forward Compton scattering in a background such as the external magnetic field or noncommutative space time. Based on this fact we explore the effects of the NC-background on the scattering of a linearly polarized laser beam from an intense beam of charged leptons. We show that for a muon/electron beam flux $\\bar\\varepsilon_{\\mu,e}\\sim 10^{12}/10^{10}\\,{\\rm TeV}\\,{\\rm cm}^{-2}\\,{\\rm sec}^{-1}$ and a linearly polarized laser beam with energy $k^0\\sim $1 eV and average power $\\bar{P}_{\\rm laser}\\simeq$1 MW, the generation rate of circularly polarized photons is about $R_{_V} \\sim 10^4/{\\rm sec}$ for Noncommutative energy scale $\\Lambda_{\\tiny{NC}}\\sim 10$TeV. This is fairly large and can grow for more intense beams in near future.

  17. Interaction of interstitial hydrogen atoms within h.c.p. metals and distribution of diffuse radiation-scattering intensity in reciprocal space

    Energy Technology Data Exchange (ETDEWEB)

    Tatarenko, V.A. [G.V. Kurdyumov Inst. for Metal Physics, Kyyiv (Ukraine). Dept. of Soilid State Theory

    2001-05-01

    A microscopic model for the strain-controlled atomic ordering of interstitial impurity atoms and for the strain-induced decomposition reaction in their solid solutions based on host crystals with a polyatomic basis is used. It takes into account the 'blocking' and static-displacements' effects in interactions between impurity atoms arranged on different-type interstices, in order to explain the salient features of distribution of the diffuse-scattering intensity in reciprocal space for such interstitial solid solutions based on some hexagonal close-packed (h.c.p.) transition and rare-earth metals. (Author)

  18. Enhanced target normal sheath acceleration of protons from intense laser interaction with a cone-tube target

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, K. D.; Huang, T. W. [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); Zhou, C. T., E-mail: zcangtao@iapcm.ac.cn [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060 (China); Qiao, B., E-mail: bqiao@pku.edu.cn [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006 (China); Wu, S. Z. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Ruan, S. C. [College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060 (China); He, X. T. [Center for Applied Physics and Technology, HEDPS, and School of Physics, Peking University, Beijing 100871 (China); Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

    2016-01-15

    Laser driven proton acceleration is proposed to be greatly enhanced by using a cone-tube target, which can be easily manufactured by current 3D-print technology. It is observed that energetic electron bunches are generated along the tube and accelerated to a much higher temperature by the combination of ponderomotive force and longitudinal electric field which is induced by the optical confinement of the laser field. As a result, a localized and enhanced sheath field is produced at the rear of the target and the maximum proton energy is about three-fold increased based on the two-dimentional particle-in-cell simulation results. It is demonstrated that by employing this advanced target scheme, the scaling of the proton energy versus the laser intensity is much beyond the normal target normal sheath acceleration (TNSA) case.

  19. Enhanced target normal sheath acceleration of protons from intense laser interaction with a cone-tube target

    Directory of Open Access Journals (Sweden)

    K. D. Xiao

    2016-01-01

    Full Text Available Laser driven proton acceleration is proposed to be greatly enhanced by using a cone-tube target, which can be easily manufactured by current 3D-print technology. It is observed that energetic electron bunches are generated along the tube and accelerated to a much higher temperature by the combination of ponderomotive force and longitudinal electric field which is induced by the optical confinement of the laser field. As a result, a localized and enhanced sheath field is produced at the rear of the target and the maximum proton energy is about three-fold increased based on the two-dimentional particle-in-cell simulation results. It is demonstrated that by employing this advanced target scheme, the scaling of the proton energy versus the laser intensity is much beyond the normal target normal sheath acceleration (TNSA case.

  20. Using a network-based approach to identify interactions structure for innovation in a low-technology intensive sector

    Energy Technology Data Exchange (ETDEWEB)

    Aouinait, C.; Lepori, B.; Christen, D.; Carlen, C.; Foray, D.

    2016-07-01

    Knowledge transfer in the agricultural network is realized through interactions between stakeholders, inducing innovation development and diffusion. The aim of the paper was to trace interactions in the Swiss apricot sector. Identification of collaborations using face-toface interviews of knowledge producers and knowledge users were conducted. The study showed that informal collaborations are exclusively used to transfer knowledge and create innovation. Personal ties have been established between internal actors of the value chain (e.g. professionals like producers, transformers and wholesalers). External partners like public research organizations have created strong ties with agricultural stakeholders. However, the spatial proximity does not guarantee higher rate of collaborations. The links with the Universities of Applied Sciences, closely located, are sparse. Hence, in order to warrant innovation success, spatial proximity has to be balanced with organizational proximity. Despite the educational background of producers, there are a few connections with universities. Human capital formation and education in the agricultural sector should be examined to design innovation policy. Besides, the public research center for agriculture catalyzes knowledge transfer and facilitates innovation adoption. A suitable ecology of actors through the value chain from research to application is necessary. Furthermore, productive interactions should be investigated to identify the efficiency of knowledge and innovation transfer mechanisms and potential gaps in this process. (Author)

  1. Estimations of electron-positron pair production at high-intensity laser interaction with high-Z targets

    CERN Document Server

    Gryaznykh, D A; Lykov, V A

    1998-01-01

    Electron-positron pairs' generation occuring in the interaction of $10^{18}$-$10^{20}$~W/cm$^2$ laser radiation with high-Z targets are examined. Computational results are presented for the pair production and the positron yield from the target with allowance for the contribution of pair production processes due to electrons and bremsstrahlung photons. Monte-Carlo simulations using the PRIZMA code confirm the estimates obtained. The possible positron yield from high-Z targets irradiated by picosecond lasers of power $10^2$-$10^3$~TW is estimated to be $10^9$-$10^{11}$.

  2. Time dependent Doppler shifts in high-order harmonic generation in intense laser interactions with solid density plasma and frequency chirped pulses

    Energy Technology Data Exchange (ETDEWEB)

    Welch, E. C.; Zhang, P.; He, Z.-H. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2104 (United States); Dollar, F. [JILA, University of Colorado, Boulder, Colorado 80309 (United States); Krushelnick, K.; Thomas, A. G. R., E-mail: agrt@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109-2104 (United States); Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2104 (United States)

    2015-05-15

    High order harmonic generation from solid targets is a compelling route to generating intense attosecond or even zeptosecond pulses. However, the effects of ion motion on the generation of harmonics have only recently started to be considered. Here, we study the effects of ion motion in harmonics production at ultrahigh laser intensities interacting with solid density plasma. Using particle-in-cell simulations, we find that there is an optimum density for harmonic production that depends on laser intensity, which scales linearly with a{sub 0} with no ion motion but with a reduced scaling if ion motion is included. We derive a scaling for this optimum density with ion motion and also find that the background ion motion induces Doppler red-shifts in the harmonic structures of the reflected pulse. The temporal structure of the Doppler shifts is correlated to the envelope of the incident laser pulse. We demonstrate that by introducing a frequency chirp in the incident pulse we are able to eliminate these Doppler shifts almost completely.

  3. Data-Intensive Science Meets Inquiry-Driven Pedagogy: Interactive Big Data Exploration, Threshold Concepts, and Liminality

    Science.gov (United States)

    Ramachandran, R.; Nair, U. S.; Word, A.

    2014-12-01

    Threshold concepts in any discipline are the core concepts an individual must understand in order to master a discipline. By their very nature, these concepts are troublesome, irreversible, integrative, bounded, discursive, and reconstitutive. Although grasping threshold concepts can be extremely challenging for each learner as s/he moves through stages of cognitive development relative to a given discipline, the learner's grasp of these concepts determines the extent to which s/he is prepared to work competently and creatively within the field itself. The movement of individuals from a state of ignorance of these core concepts to one of mastery occurs not along a linear path but in iterative cycles of knowledge creation and adjustment in liminal spaces - conceptual spaces through which learners move from the vaguest awareness of concepts to mastery, accompanied by understanding of their relevance, connectivity, and usefulness relative to questions and constructs in a given discipline. With the explosive growth of data available in atmospheric science, driven largely by satellite Earth observations and high-resolution numerical simulations, paradigms such as that of data-intensive science have emerged. These paradigm shifts are based on the growing realization that current infrastructure, tools and processes will not allow us to analyze and fully utilize the complex and voluminous data that is being gathered. In this emerging paradigm, the scientific discovery process is driven by knowledge extracted from large volumes of data. In this presentation, we contend that this paradigm naturally lends to inquiry-driven pedagogy where knowledge is discovered through inductive engagement with large volumes of data rather than reached through traditional, deductive, hypothesis-driven analyses. In particular, data-intensive techniques married with an inductive methodology allow for exploration on a scale that is not possible in the traditional classroom with its typical

  4. Improvement of localised corrosion resistance of AISI 2205 Duplex Stainless Steel joints made by gas metal arc welding under electromagnetic interaction of low intensity

    Energy Technology Data Exchange (ETDEWEB)

    García-Rentería, M.A., E-mail: crazyfim@gmail.com [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); López-Morelos, V.H., E-mail: vhlopez@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); García-Hernández, R., E-mail: rgarcia@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); Dzib-Pérez, L., E-mail: luirdzib@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); García-Ochoa, E.M., E-mail: emgarcia@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); González-Sánchez, J., E-mail: jagonzal@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico)

    2014-12-01

    Highlights: • Electromagnetic interaction in welding improved localised corrosion resistance. • Electromagnetic interaction in welding enhanced γ/δ phase balance of DuplexSS. • Welding under Electromagnetic interaction repress formation and growth of detrimental phases. • Welds made with gas protection (2% O{sub 2} + 98% Ar) have better microstructural evolution during welding. - Abstract: The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O{sub 2} (M1) and 97% Ar + 3% N{sub 2} (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.

  5. Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Warren, B.

    2012-12-01

    We present results from the grant entitled, Continuation of full-scale three-dimensional numerical experiments on high-intensity particle and laser beam-matter interactions. The research significantly advanced the understanding of basic high-energy density science (HEDS) on ultra intense laser and particle beam plasma interactions. This advancement in understanding was then used to to aid in the quest to make 1 GeV to 500 GeV plasma based accelerator stages. The work blended basic research with three-dimensions fully nonlinear and fully kinetic simulations including full-scale modeling of ongoing or planned experiments. The primary tool was three-dimensional particle-in-cell simulations. The simulations provided a test bed for theoretical ideas and models as well as a method to guide experiments. The research also included careful benchmarking of codes against experiment. High-fidelity full-scale modeling provided a means to extrapolate parameters into regimes that were not accessible to current or near term experiments, thereby allowing concepts to be tested with confidence before tens to hundreds of millions of dollars were spent building facilities. The research allowed the development of a hierarchy of PIC codes and diagnostics that is one of the most advanced in the world.

  6. Integration of the Lorentz-Dirac equation: Interaction of an intense laser pulse with high-energy electrons.

    Science.gov (United States)

    Koga, James

    2004-10-01

    Usually the motion of an electron under the influence of electromagnetic fields is influenced to a small extent by radiation damping. With the advent of high power high irradiance lasers it has become possible to generate focused laser irradiances where electrons interacting with the laser become highly relativistic over very short time and spatial scales. By focusing petawatt class lasers to very small spot sizes the amount of radiation emitted by electrons can become very large. Resultingly, the damping of the electron motion by the emission of this radiation can become large. In order to study this problem a code is written to solve a set of equations describing the evolution of a strong electromagnetic wave interacting with a single electron. Usually the equation of motion of an electron including radiation damping under the influence of electromagnetic fields is derived from the Lorentz-Dirac equation treating the damping as a perturbation. We use this equation to integrate forward in time and use the Lorentz-Dirac equation to integrate backward in time. We show that for very short wavelength electromagnetic radiation deep in the quantum regime at high irradiances differences between the perturbation equation and Lorentz-Dirac can be seen. However, for electron motion in the classical regime the differences are negligible. For electron motion in the classical regime the first order damping equation is found to be very adequate.

  7. Interactive effects of redox intensity and phosphate availability on growth and nutrient relations of Cladium jamaicense (Cyperaceae)

    Science.gov (United States)

    Lissner, J.; Mendelssohn, I.A.; Lorenzen, B.; Brix, H.; McKee, K.L.; Miao, S.L.

    2003-01-01

    Expansion of Typha domingensis into areas previously dominated by Cladium jamaicense in the Florida Everglades has been linked to anthropogenic phosphorus (P) enrichment and increased hydroperiod. The principal stress factor for plants in flooded soils is biochemical reduction, the intensity of which is measured as redox potential (Eh). The objective of this study was to assess the growth response of C. jamaicense to Eh (-150, +150, and +600 mV) and P availability (10, 80, and 500 ??g P/L). Plants were grown hydroponically in a factorial experiment using titanium (Ti3+) citrate as an Eh buffer. Treatment effects on growth, biomass partitioning, and tissue nutrients were recorded. Growth approximately doubled in response to a 50-fold increase in P availability. Low redox significantly reduced growth and tissue P concentration. While plant P concentrations increased 20-fold between the 10 and 500 ??g P/L treatments, P concentrations were 50-100% higher at +600 mV than at -150 mV within each phosphate level. At high Eh, C. jamaicense appears well adapted to low nutrient environments because of its low P requirement and high retention of acquired E However, at low Eh the ability to acquire or conserve acquired P decreases and as a consequence, higher phosphate levels are required to sustain growth. Findings of this study indicate that young C. jamaicense exhibits low tolerance to strongly reducing conditions when phosphate is scarce.

  8. Interaction between Gender and Skill on Competitive State Anxiety Using the Time-to-Event Paradigm: What Roles Do Intensity, Direction, and Frequency Dimensions Play?

    Science.gov (United States)

    Hagan, John E.; Pollmann, Dietmar; Schack, Thomas

    2017-01-01

    Background and purpose: The functional understanding and examination of competitive anxiety responses as temporal events that unfold as time-to-competition moves closer has emerged as a topical research area within the domains of sport psychology. However, little is known from an inclusive and interaction oriented perspective. Using the multidimensional anxiety theory as a framework, the present study examined the temporal patterning of competitive anxiety, focusing on the dimensions of intensity, direction, and frequency of intrusions in athletes across gender and skill level. Methods: Elite and semi-elite table tennis athletes from the Ghanaian league (N = 90) completed a modified version of Competitive State Anxiety Inventory-2 (CSAI-2) with the inclusion of the directional and frequency of intrusion scales at three temporal phases (7 days, 2 days, and 1 h) prior to a competitive fixture. Results: Multivariate Analyses of Variance repeated measures with follow-up analyses revealed significant interactions for between-subjects factors on all anxiety dimensions (intensity, direction, and frequency). Notably, elite (international) female athletes were less cognitively anxious, showed more facilitative interpretation toward somatic anxiety symptoms and experienced less frequency of somatic anxiety symptoms than their male counterparts. However, both elite groups displayed appreciable level of self-confidence. For time-to-event effects, both cognitive and somatic anxiety intensity fluctuated whereas self-confidence showed a steady rise as competition neared. Somatic anxiety debilitative interpretation slightly improved 1 h before competition whereas cognitive anxiety frequencies also increased progressively during the entire preparatory phase. Conclusion: Findings suggest a more dynamic image of elite athletes’ pre-competitive anxiety responses than suggested by former studies, potentially influenced by cultural differences. The use of psychological skills

  9. Interaction between Gender and Skill on Competitive State Anxiety Using the Time-to-Event Paradigm: What Roles Do Intensity, Direction, and Frequency Dimensions Play?

    Directory of Open Access Journals (Sweden)

    John E. Hagan

    2017-05-01

    Full Text Available Background and purpose: The functional understanding and examination of competitive anxiety responses as temporal events that unfold as time-to-competition moves closer has emerged as a topical research area within the domains of sport psychology. However, little is known from an inclusive and interaction oriented perspective. Using the multidimensional anxiety theory as a framework, the present study examined the temporal patterning of competitive anxiety, focusing on the dimensions of intensity, direction, and frequency of intrusions in athletes across gender and skill level.Methods: Elite and semi-elite table tennis athletes from the Ghanaian league (N = 90 completed a modified version of Competitive State Anxiety Inventory-2 (CSAI-2 with the inclusion of the directional and frequency of intrusion scales at three temporal phases (7 days, 2 days, and 1 h prior to a competitive fixture.Results: Multivariate Analyses of Variance repeated measures with follow-up analyses revealed significant interactions for between-subjects factors on all anxiety dimensions (intensity, direction, and frequency. Notably, elite (international female athletes were less cognitively anxious, showed more facilitative interpretation toward somatic anxiety symptoms and experienced less frequency of somatic anxiety symptoms than their male counterparts. However, both elite groups displayed appreciable level of self-confidence. For time-to-event effects, both cognitive and somatic anxiety intensity fluctuated whereas self-confidence showed a steady rise as competition neared. Somatic anxiety debilitative interpretation slightly improved 1 h before competition whereas cognitive anxiety frequencies also increased progressively during the entire preparatory phase.Conclusion: Findings suggest a more dynamic image of elite athletes’ pre-competitive anxiety responses than suggested by former studies, potentially influenced by cultural differences. The use of psychological

  10. Broadband Brillouin Scatter from CO2-Laser-Target Interactions

    Science.gov (United States)

    Mitchel, G. R.; Grek, B.; Johnston, T. W.; Pépin, H.; Church, P.; Lavigne, P.; Martin, F.; Décoste, R.

    1982-05-01

    Light scattered near the incident wavelength from CO2 laser-solid target interactions in oblique incidence shows the spectral signature of Brillouin scattering both in the backward and in the near specular directions. This instability is apparently seeded by broadband scatter from the critical density surface and then amplified in the underdense plasma. 60% of the incident light is scattered, and the Brillouin contribution to total scatter may be large if the source is also large.

  11. Production of intense beams of mass-selected water cluster ions and theoretical study of atom-water interactions

    CERN Document Server

    Wang, Z P; Reinhard, P -G; Suraud, E; Bruny, G; Montano, C; Feil, S; Eden, S; Abdoul-Carime, H; Farizon, B; Farizon, M; Ouaskit, S; Maerk, T D

    2009-01-01

    The influences of water molecules surrounding biological molecules during irradiation with heavy particles (atoms,ions) are currently a major subject in radiation science on a molecular level. In order to elucidate the underlying complex reaction mechanisms we have initiated a joint experimental and theoretical investigation with the aim to make direct comparisons between experimental and theoretical results. As a first step, studies of collisions of a water molecule with a neutral projectile (C atom) at high velocities (> 0.1 a.u.), and with a charged projectile (proton) at low velocities (< 0.1 a.u.) have been studied within the microscopic framework. In particular, time-dependent density functional theory (TDDFT) was applied to the valence electrons and coupled non-adiabatically to Molecular dynamics (MD) for ionic cores. Complementary experimental developments have been carried out to study projectile interactions with accelerated (< 10 keV) and mass-selected cluster ions. The first size distributio...

  12. Data-Intensive Science meets Inquiry-Driven Pedagogy: Interactive Big Data Exploration, Threshold Concepts, and Liminality

    Science.gov (United States)

    Ramachandran, Rahul; Word, Andrea; Nair, Udasysankar

    2014-01-01

    us to analyze and fully utilize the complex and voluminous data that is being gathered. In this emerging paradigm, the scientific discovery process is driven by knowledge extracted from large volumes of data. In this presentation, we contend that this paradigm naturally lends to inquiry-driven pedagogy where knowledge is discovered through inductive engagement with large volumes of data rather than reached through traditional, deductive, hypothesis-driven analyses. In particular, data-intensive techniques married with an inductive methodology allow for exploration on a scale that is not possible in the traditional classroom with its typical problem sets and static, limited data samples. In addition, we identify existing gaps and possible solutions for addressing the infrastructure and tools as well as a pedagogical framework through which to implement this inductive approach.

  13. Investigation of interactions of intense plasma streams with tungsten and carbon fibre composite targets in the PF-1000 facility

    Science.gov (United States)

    Kubkowska, Monika; Skladnik-Sadowska, Elzbieta; Kwiatkowski, Roch; Malinowski, Karol; Kowalska-Strzęciwilk, Ewa; Paduch, Marian; Sadowski, Marek J.; Pisarczyk, Tadeusz; Chodukowski, Tomasz; Kalinowska, Zofia; Zielinska, Ewa; Scholz, Marek

    2014-05-01

    This paper presents the results of research on interactions of pulsed plasma streams, as generated by the PF-1000 facility, with solid targets made of tungsten or carbon fibre composite. The device was equipped with a modified inner electrode with a central tungsten insert of 50 mm in diameter. The PF-1000 experimental chamber was filled with pure deuterium at p0 = 1.47 hPa. At the charging voltage U0 = 24 kV, the maximum current amounted to 1.8 MA in about 5.5 μs after the discharge initiation. The investigated targets were located on the z-axis, at a distance of 9 cm from the inner electrode end. For plasma diagnostics, optical emission spectroscopy, 16-frame laser interferometry and a soft x-ray measuring system of four silicon pin diodes were used. It was observed that plasma streams reached the target about 100 ns after the maximum compression and generated a plasma pillow at the sample surface, as proved from time-resolved optical spectra.

  14. Prevalência de interações medicamentosas em unidades de terapia intensiva no Brasil Prevalence of drug interactions in intensive care units in Brazil

    Directory of Open Access Journals (Sweden)

    Rhanna Emanuela Fontenele Lima de Carvalho

    2013-01-01

    Full Text Available OBJETIVO: Determinar a prevalência de interações medicamentosas em unidades de terapia intensiva e analisar a significância clínica das interações identificadas. MÉTODOS: Estudo multicêntrico, transversal e retrospectivo desenvolvido com 1124 pacientes em sete unidades de terapia intensiva (UTI de hospitais de ensino no Brasil. As informações sobre os medicamentos administrados com 24 horas e 120 horas de internação foram obtidas nas prescrições. RESULTADOS: Em 24 horas 70,6% dos pacientes apresentaram pelo menos uma interação medicamentosa. O número de interações medicamentosas detectadas em 24 horas foi 2299 e em 120 horas foi 2619. Midazolam, fentanil, fenitoína e omeprazol foram os fármacos com maior frequência de interações medicamentosas. CONCLUSÃO: Nesta amostra, interações medicamentosas moderadas e graves foram mais prevalentes. Diante desses resultados, todas as ações dos profissionais de saúde que prestam assistência ao paciente devem ser integradas visando identificar e prevenir possíveis eventos a medicamentos.OBJECTIVE: To determine the prevalence of drug interactions in intensive care units and to analyze the clinical significance of interactions identified. METHODS: A multicenter, retrospective and cross sectional study conducted with 1124 patients in the seven intensive care units of teaching hospitals in Brazil. Information on drugs administered at 24 hours and 120 hours of hospitalization was obtained from the prescriptions. RESULTS: Within 24 hours, 70.6% of patients had at least one drug interaction; the number at 24h was 2299, at 120 h it was 2619. Midazolam, fentanyl, phenytoin and omeprazole were the drugs with higher frequency of drug interactions. CONCLUSION: In this sample, moderate and severe drug interactions were more prevalent. In light of these findings, all actions of health professionals who provide care to these patients must be integrated in order to identify and prevent

  15. Influence of the interaction between light intensity and CO2 concentration on productivity and quality of spinach (Spinacia oleracea L.) grown in fully controlled environment

    Science.gov (United States)

    Proietti, Simona; Moscatello, Stefano; Giacomelli, Gene A.; Battistelli, Alberto

    2013-09-01

    The effects of the factorial combination of two light intensities (200 and 800 μmol m-2 s-1) and two CO2 concentrations (360 and 800 ppm) were studied on the productivity and nutritional quality of spinach (Spinacia oleracea L.) grown under controlled environment. After 6 weeks within a growth chamber, spinach plants were sampled and analyzed for productivity and quality. There were no statistically significant interactions between the effects of light and CO2 for all of the variables studied, except for the nitrate and oxalic acid content of the leaves. High light and high CO2 independently one from the other, promoted spinach productivity, and the accumulation of ascorbic acid, while their interactive effect limited the accumulation of nitrate and oxalic acid in the spinach leaves. The results highlight the importance of considering the effects of the interaction among environmental variables on maximizing production and the nutritional quality of the food when cultivating and modeling the plant response in controlled environment systems such as for bioregenerative life support.

  16. Strong Radiation-Damping Effects in a Gamma-Ray Source Generated by the Interaction of a High-Intensity Laser with a Wakefield-Accelerated Electron Beam

    Science.gov (United States)

    Thomas, A. G. R.; Ridgers, C. P.; Bulanov, S. S.; Griffin, B. J.; Mangles, S. P. D.

    2012-10-01

    A number of theoretical calculations have studied the effect of radiation-reaction forces on radiation distributions in strong-field counterpropagating electron-beam-laser interactions, but could these effects—including quantum corrections—be observed in interactions with realistic bunches and focusing fields, as is hoped in a number of soon-to-be-proposed experiments? We present numerical calculations of the angularly resolved radiation spectrum from an electron bunch with parameters similar to those produced in laser-wakefield-acceleration experiments, interacting with an intense, ultrashort laser pulse. For our parameters, the effect of radiation damping on the angular distribution and energy distribution of photons is not easily discernible for a realistic moderate-emittance electron beam. However, experiments using such a counterpropagating beam-laser geometry should be able to measure these effects using current laser systems through measurement of the electron-beam properties. In addition, the brilliance of this source is very high, with peak spectral brilliance exceeding 1029photonss-1mm-2mrad-2(0.1%bandwidth)-1 with an approximately 2% conversion efficiency and with a peak energy of 10 MeV.

  17. The effect of parent training in music and multimodal stimulation on parent-neonate interactions in the neonatal intensive care unit.

    Science.gov (United States)

    Whipple, J

    2000-01-01

    This study examined the effects of parent training in music and multimodal stimulation on the quantity and quality of parent-neonate interactions and the weight gain and length of hospitalization of premature and low birthweight (LBW) infants in a Neonatal Intensive Care Unit (NICU). Twenty sets of parents and premature LBW infants participated in the study. Parents in the experimental group (n = 10) received approximately one hour of instruction in appropriate uses of music, multimodal stimulation including massage techniques, and signs of infant overstimulation and techniques for its avoidance. Parent-neonate interactions, specifically parent actions and responses and infant stress and nonstress behaviors, were observed for subjects in both groups. Infant stress behaviors were significantly fewer and appropriateness of parent actions and responses were significantly greater for experimental infants and parents than for control subjects. Parents in the experimental group also self-reported spending significantly more time visiting in the NICU than did parents of control infants. In addition, length of hospitalization was shorter and average daily weight gain was greater for infants whose parents received training, although these differences were not significant. A one month, postdischarge follow-up showed little difference between experimental and control group parent-infant interactions in the home.

  18. The impact of R&D intensity on corporate reputation: Interaction effect of innovation with high social benefit The impact of R&D intensity on corporate reputation: Interaction effect of innovation with high social benefit The impact of R&D intensity on corporate reputation: Interaction effect of innovation with high social benefit

    Directory of Open Access Journals (Sweden)

    Rosamaria Cox Moura-Leite

    2012-06-01

    Full Text Available Purpose: This article analyzes the effect that Research and Development (R&D intensity has on corporate reputation, and how this effect can be positively moderated when innovation yields some kind of social benefits.Design/methodology/approach: As a theoretical framework we use the resource based view theory and the institutional theory. For the empirical analysis we used the panel data technique to estimate our models, the sample is composed of 257 US firms and covers a four-year period from 2004 to 2007. Findings: The results of this research demonstrates that R&D with the moderation of innovation with high social benefits will produce a greater positive effect on corporate reputation than R&D by itself, since R&D activities can produce innovations that do not produce any social benefit which may not be perceived by stakeholders.Practical implications: Innovative firms should focus their efforts on identifying opportunities in their R&D processes to initiate related corporate social responsibility activities that could help them build a good reputation, which in the long run can give them a competitive advantage and profitable results.Originality/value: Recently several studies have seen that R&D is related with corporate social responsibility and that it is important to include both variables when studying financial performance. Our research is novel in the sense that we are applying the same logic but studying the relationship with corporate reputation, which has been scarcely talked about in existing literature.Purpose: This article analyzes the effect that Research and Development (R&D intensity has on corporate reputation, and how this effect can be positively moderated when innovation yields some kind of social benefits.Design/methodology/approach: As a theoretical framework we use the resource based view theory and the institutional theory. For the empirical analysis we used the panel data technique to estimate our models, the sample

  19. Improvement of localised corrosion resistance of AISI 2205 Duplex Stainless Steel joints made by gas metal arc welding under electromagnetic interaction of low intensity

    Science.gov (United States)

    García-Rentería, M. A.; López-Morelos, V. H.; García-Hernández, R.; Dzib-Pérez, L.; García-Ochoa, E. M.; González-Sánchez, J.

    2014-12-01

    The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O2 (M1) and 97% Ar + 3% N2 (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.

  20. Identifying the source of super-high energetic electrons in the presence of pre-plasma in laser-matter interaction at relativistic intensities

    CERN Document Server

    Wu, D; Luan, S X; Yu, W

    2015-01-01

    The generation of super-high energetic electrons influenced by pre-plasma in relativistic intensity laser matter interaction is studied in a one-dimensional slab approximation with particle-in-cell simulations. Different pre-plasma scale-lengths of $1\\ \\mu\\text{m}$, $5\\ \\mu\\text{m}$, $10\\ \\mu\\text{m}$ and $15\\ \\mu\\text{m}$ are considered, showing an increase in both particle number and cut-off kinetic energy of energetic electrons with the increase of pre-plasma scale-length, and the obtained cut-off electron energies greatly exceeding the ponderomotive energies. A two-stage electron acceleration model is proposed to explain the underlying physics. The first stage is attributed to the synergetic acceleration by longitudinal electric field and laser pulse, with the efficiency depending on the pre-plasma scale-length. The fast electrons pre-accelerated in the first stage could build up an intense electrostatic potential with the potential energy several times as large of the initial electron kinetic energy. Par...

  1. SLAC/DESY International Workshop on Interactions of Intense Sub-Picosecond X-Rays with Matter, Stanford, CA, January 23-24, 1997

    CERN Document Server

    Tatchyn, R

    1998-01-01

    This is the proceedings volume of the 1997 SLAC/DESY International Workshop on Interactions of Intense Sub-picosecond X-Ray Pulses with Matter. The workshop theme evolved out of design and R and D studies, undertaken at SLAC, DESY, and elsewhere [1,2], of the new class of linac-driven X-Ray Free Electron Lasers (XRFELs) operating with photocathode-based, low-emittance electron beams in the Self-Amplified Spontaneous Emission (SASE) regime [3]. It can be noted that, following the conclusion of the workshop, funded design study reports on R and D facilities based on these novel sources have been completed and published by both laboratories [4,5]. Topical significance was imparted to the workshop agenda by a series of prior workshops organized to explore scientific and technological applications of linac driven XRFELs [6,7,8,9]. These served to highlight underlying concerns regarding the potential loading effects of the highly intense radiation pulses from this new class of light source on the instrumentation, s...

  2. Dose-Dependent Effects of L-Arginine on PROP Bitterness Intensity and Latency and Characteristics of the Chemical Interaction between PROP and L-Arginine.

    Directory of Open Access Journals (Sweden)

    Melania Melis

    Full Text Available Genetic variation in the ability to taste the bitterness of 6-n-propylthiouracil (PROP is a complex trait that has been used to predict food preferences and eating habits. PROP tasting is primarily controlled by polymorphisms in the TAS2R38 gene. However, a variety of factors are known to modify the phenotype. Principle among them is the salivary protein Ps-1 belonging to the basic proline-rich protein family (bPRP. Recently, we showed that oral supplementation with Ps-1 as well as its related free amino acids (L-Arg and L-Lys enhances PROP bitterness perception, especially for PROP non-tasters who have low salivary levels of Ps-1. Here, we show that salivary L-Arg levels are higher in PROP super-tasters compared to medium tasters and non-tasters, and that oral supplementation with free L-Arg enhances PROP bitterness intensity as well as reduces bitterness latency in a dose-dependent manner, particularly in individuals with low salivary levels of both free L-Arg and Ps-1 protein. Supplementation with L-Arg also enhanced the bitterness of caffeine. We also used 1H-NMR spectroscopy and quantum-mechanical calculations carried out by Density Functional Theory (DFT to characterize the chemical interaction between free L-Arg and the PROP molecule. Results showed that the -NH2 terminal group of the L-ArgH+ side chain interacts with the carbonyl or thiocarbonyl groups of PROP by forming two hydrogen bonds with the resulting charged adduct. The formation of this PROP•ArgH+ hydrogen-bonded adduct could enhance bitterness intensity by increasing the solubility of PROP in saliva and its availability to receptor sites. Our data suggest that L-Arg could act as a 'carrier' of various bitter molecules in saliva.

  3. Dose-Dependent Effects of L-Arginine on PROP Bitterness Intensity and Latency and Characteristics of the Chemical Interaction between PROP and L-Arginine.

    Science.gov (United States)

    Melis, Melania; Arca, Massimiliano; Aragoni, Maria Carla; Cabras, Tiziana; Caltagirone, Claudia; Castagnola, Massimo; Crnjar, Roberto; Messana, Irene; Tepper, Beverly J; Tomassini Barbarossa, Iole

    2015-01-01

    Genetic variation in the ability to taste the bitterness of 6-n-propylthiouracil (PROP) is a complex trait that has been used to predict food preferences and eating habits. PROP tasting is primarily controlled by polymorphisms in the TAS2R38 gene. However, a variety of factors are known to modify the phenotype. Principle among them is the salivary protein Ps-1 belonging to the basic proline-rich protein family (bPRP). Recently, we showed that oral supplementation with Ps-1 as well as its related free amino acids (L-Arg and L-Lys) enhances PROP bitterness perception, especially for PROP non-tasters who have low salivary levels of Ps-1. Here, we show that salivary L-Arg levels are higher in PROP super-tasters compared to medium tasters and non-tasters, and that oral supplementation with free L-Arg enhances PROP bitterness intensity as well as reduces bitterness latency in a dose-dependent manner, particularly in individuals with low salivary levels of both free L-Arg and Ps-1 protein. Supplementation with L-Arg also enhanced the bitterness of caffeine. We also used 1H-NMR spectroscopy and quantum-mechanical calculations carried out by Density Functional Theory (DFT) to characterize the chemical interaction between free L-Arg and the PROP molecule. Results showed that the -NH2 terminal group of the L-ArgH+ side chain interacts with the carbonyl or thiocarbonyl groups of PROP by forming two hydrogen bonds with the resulting charged adduct. The formation of this PROP•ArgH+ hydrogen-bonded adduct could enhance bitterness intensity by increasing the solubility of PROP in saliva and its availability to receptor sites. Our data suggest that L-Arg could act as a 'carrier' of various bitter molecules in saliva.

  4. Integrated Laser-Target Interaction Experiments on the RAL Petawatt Laser

    Energy Technology Data Exchange (ETDEWEB)

    Patel, P. K.; Key, M. H.; Mackinnon, A. J.; Akli, K.; Berry, R.; Borghesi, M.; Brummit, P. A.; Chambers, D.; Clarke, R. J.; Damian, C.; Chen, H.; Eagleton, R.; Freeman, R.; Glenzer, S.; Gregori, G.; Heathcote, R.; Izumi, N.; Kar, S.; King, J. A.; Kock, J.; Kuba, J.; May, M.; Moon, S.; Neely, D.; Neville, D. R.; Nikroo, A.; Niles, A.; Pasley, J.; Patel, N.; Park, H. S.; Romagnani, L.; Shepherd, R.; Snavely, R. A.; Stephens, R.; Stoeckl, C.; Storm, M.; Theobald, W.; Van Maren, R.; Wilks, S. C.; Zhang, B.

    2005-07-01

    We report on two recent experimental campaigns performed on the new Petawatt laser at the Rutherford Appleton Laboratory in the UK.The laser has recently demonstrated performance characteristics of 400 J of laser energy being delivered on target in a sub 400 fs pulse, reaching a peak focal intensity on the order of 10''21 W/cm''2. The experiments covered multiplic areas of investigation including hot electron transport in planar foil and cone focus geometries, relativistic laser-solid interactions proton beam focusing and heating, and high energy K-alpha production and radiography. A somewhat novel approach was taken to the experiments in that all of the diagnostics required for the different areas of study were fielded simultaneously and operated on all shots. Thus, we were able to obtain extensive sets of measurements on a single-shot basis which provides significant benefit to our understanding of the laser-target interaction conditions and plasma properties. (Author)

  5. Strong radiation damping effects in a gamma-ray source generated by the interaction of a high intensity laser with a wakefield accelerated electron beam

    Science.gov (United States)

    Thomas, Alexander; Ridgers, Christopher; Bulanov, Stepan; Griffin, Blake; Mangles, Stuart

    2012-10-01

    We present numerical calculations of the angularly resolved radiation spectrum from a relativistic electron beam interacting with an ultrashort laser pulse. These calculations include the effect of semi-classical radiation reaction forces including a Gaunt factor for synchrotron radiation. For a laser of 5x10^21 Wcm-2 intensity interacting with a 200 MeV electron beam with an emittance similar to that in laser wakefield acceleration experiments, radiation reaction does not produce a significant change in the angular and energy distribution of photons. However the effects of radiation reaction are clear when observing the electron beam properties. The result is that near-term experiments using such a counter-propagating beam-laser geometry should be able to measure the effects of quantum effects in radiation reaction. The calculations also show that the brilliance of this source is very high, with a peak spectral brilliance exceeding 10^29 photons,s-1mm-2mrad-2(0.1% bandwidth)-1 with approximately 2% efficiency and with a peak energy of 10 MeV.

  6. High harmonic generation in H$_{2}^{+}$ and HD+ by intense femtosecond laser pulses: A wave packet approach with nonadiabatic interaction in HD+

    Indian Academy of Sciences (India)

    Farzana Sharmin; Samir Saha; S S Bhattacharyya

    2013-06-01

    We have theoretically investigated the high harmonic generation (HHG) spectra of H$_{2}^{+}$ and HD+ using a time-dependent wave packet approach for the nuclear motion with pulsed lasers of peak intensities (0) of 3.5 × 1014 and 4.5 × 1014 W/cm2, wavelengths (L) of 800 and 1064 nm, and pulse durations () of 40 and 50 fs, for initial vibrational levels 0 = 0 and 1. We have argued that for these conditions the harmonic generation due to the transitions in the electronic continuum by tunnelling or multiphoton ionization will not be important. Thus, the characteristic features of HHG spectra in our model arise only due to the nuclear motions on the two lowest field-coupled electronic states between which both interelectronic and intraelectronic (due to intrinsic dipole moments, for HD+) radiative transitions can take place. For HD+, the effect of nonadiabatic (NA) interaction between the two lowest Born–Oppenheimer (BO) electronic states has been taken into account and comparison has been made with the HHG spectra of HD+ obtained in the BO approximation. Even harmonics and a second plateau in the HHG spectra of HD+ with the NA interaction and hyper-Raman lines in the spectra of both H$_{2}^{+}$ and HD+ for 0 = 1 have been observed for higher value of 0 or L. Our calculations indicate reasonable efficiencies of harmonic generation even without involving the electronic continuum.

  7. The Effect of Interactive Web-Based Monitoring on Breastfeeding Exclusivity, Intensity, and Duration in Healthy, Term Infants After Hospital Discharge.

    Science.gov (United States)

    Ahmed, Azza H; Roumani, Ali M; Szucs, Kinga; Zhang, Lingsong; King, Demetra

    2016-01-01

    To determine whether a Web-based interactive breastfeeding monitoring system increased breastfeeding duration, exclusivity, and intensity as primary outcomes and decreased symptoms of postpartum depression as a secondary outcome. Two-arm, randomized controlled trial. Three hospitals in the Midwestern United States. One hundred forty one (141) mother-newborn dyads were recruited before discharge. Postpartum women were randomly assigned to the control or intervention groups. Women in the control group (n = 57) followed the standard hospital protocol, whereas women in the intervention group (n = 49) were given access to an online interactive breastfeeding monitoring system and were prompted to record breastfeeding and infant output data for 30 days. A follow-up online survey was sent to both groups at 1, 2, and 3 months to assess breastfeeding outcomes and postpartum depression. For mothers and infants, there were no significant differences in demographics between groups. No significant differences in breastfeeding outcomes were found between groups at discharge (p = .707). A significant difference in breastfeeding outcomes was found between groups at 1, 2, and 3 months (p = .027, p < .001, and p = .002, respectively). Members of the intervention group had greater exclusive breastfeeding rates at 1, 2, and 3 months. By the end of the third month, 84% of the intervention group was breastfeeding compared with 66% of the control group. Postpartum depression symptom scores decreased for both groups at 1, 2, and 3 months (control group: 4.9 ± 3.9, 4.3 ± 4.9, and 3.2 ± 3.9, respectively; intervention group: 4.7 ± 4.5, 3.0 ± 3.4, and 2.8 ± 3.6, respectively). However, there was no significant difference between groups at 1, 2, and 3 months (p = .389, .170, and .920, respectively) for depression. The Web-based interactive breastfeeding monitoring system may be a promising intervention to improve breastfeeding duration, exclusivity, and intensity. Copyright © 2016

  8. Interactive GPU-based maximum intensity projection of large medical data sets using visibility culling based on the initial occluder and the visible block classification.

    Science.gov (United States)

    Kye, Heewon; Sohn, Bong-Soo; Lee, Jeongjin

    2012-07-01

    Maximum intensity projection (MIP) is an important visualization method that has been widely used for the diagnosis of enhanced vessels or bones by rotating or zooming MIP images. With the rapid spread of multidetector-row computed tomography (MDCT) scanners, MDCT scans of a patient generate a large data set. However, previous acceleration methods for MIP rendering of such a data set failed to generate MIP images at interactive rates. In this paper, we propose novel culling methods in both object and image space for interactive MIP rendering of large medical data sets. In object space, for the visibility test of a block, we propose the initial occluder resulting from a preceding image to utilize temporal coherence and increase the block culling ratio a lot. In addition, we propose the hole filling method using the mesh generation and rendering to improve the culling performance during the generation of the initial occluder. In image space, we find out that there is a trade-off between the block culling ratio in object space and the culling efficiency in image space. In this paper, we classify the visible blocks into two types by their visibility. And we propose a balanced culling method by applying a different culling algorithm in image space for each type to utilize the trade-off and improve the rendering speed. Experimental results on twenty CT data sets showed that our method achieved 3.85 times speed up in average without any loss of image quality comparing with conventional bricking method. Using our visibility culling method, we achieved interactive GPU-based MIP rendering of large medical data sets.

  9. Intense Laser - Electron Beam Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, T.; Ditmire, T.; LeSage, G.

    2000-02-25

    Applicants seeking a Certificate of Compliance for an Independent Spent Fuel Storage Installation (ISFSI) cask must evaluate the consequences of a handling accident resulting in a drop or tip-over of the cask onto a concrete storage pad. As a result, analytical modeling approaches that might be used to evaluate the impact of cylindrical containers onto concrete pads are needed. One such approach, described and benchmarked in NUREG/CR-6608,{sup 1} consists of a dynamic finite element analysis using a concrete material model available in DYNA3D{sup 2} and in LS-DYNA,{sup 3} together with a method for post-processing the analysis results to calculate the deceleration of a solid steel billet when subjected to a drop or tip-over onto a concrete storage pad. The analysis approach described in NUREG/CR-6608 gives a good correlation of analysis and test results. The material model used for the concrete in the analyses in NUREG/CR-6608 is, however, somewhat troublesome to use, requiring a number of material constants which are difficult to obtain. Because of this a simpler approach, which adequately evaluates the impact of cylindrical containers onto concrete pads, is sought. Since finite element modeling of metals, and in particular carbon and stainless steel, is routinely and accurately accomplished with a number of finite element codes, the current task involves a literature search for and a discussion of available concrete models used in finite element codes. The goal is to find a balance between a concrete material model with a limited number of required material parameters which are readily obtainable, and a more complex model which is capable of accurately representing the complex behavior of the concrete storage pad under impact conditions. The purpose of this effort is to find the simplest possible way to analytically represent the storage cask deceleration during a cask tip-over or a cask drop onto a concrete storage pad. This report is divided into three sections. The Section II provides a summary of the literature search on concrete finite element models. The Section III discusses commercial codes. The Section IV provides recommendations.

  10. An Analysis of the Interactive Development between Lhasa and Shigatse from the Perspective of the Intensity of their Economic Contact and Regional Breaking Point

    Institute of Scientific and Technical Information of China (English)

    QIU Lilan

    2014-01-01

    In the Tibet Autonomous Region , Lhasa and Shigatse are the two core cities in the region’ s development , and they play a leading role for the development of other counties and cit-ies.From the perspective of research on urban ag-glomeration and urban geography , the two cities have a relationship of interactive contact and com-mon development .Within the context of rapid ur-banization in China , the interactive development between Lhasa and Shigatse has become an inevita-ble research focus for the socio-economic construc-tion of Tibet . The intensity of economic contact is used tomeasure the degree of regional economic ties.Onthe one hand, it can reflect the city’ s economiccenter ability to radiate out to the surrounding areas.On the other hand, it can also reflect the levelof acceptance of the surrounding areas to the city’s economic center ability to radiate out tothem.According to the results of economic calculation,the intensity of economic contact betweenLhasa and Shigatse from 2007 to 2011 steadily increasedwith an annual rate of about 20%.Thecontinuous increase of the intensity of economiccontact also meant that the influence of Lhasa andShigatse on the surrounding cities is expanding .Moreover, comparative data show that due to restrictionson the population and level of economicdevelopment, there is still a big gap in Lhasa andShigatse if compared with other urbanized areas inChina.However, regarding the increasing speedof the intensity of contact with other core cities,Lhasa and Shigatse have achieved remarkable a -chievements. During the 1930’ s, William J.Reilly proposedthe Law of Retail Gravitation which was usedby P.D.Converse in the field of urban managementto differentiate the scope of influence ofneighboring cities.In 1949, he put forward theconcept of “Breaking Point” together with a relevantcomputational formula.The Breaking Point isnormally determined by the scale of two cities andthe distance between them.According to the

  11. Effects of electron recirculation on a hard x-ray source observed during the interaction of a high intensity laser pulse with thin Au targets

    Science.gov (United States)

    Compant La Fontaine, A.; Courtois, C.; Lefebvre, E.; Bourgade, J. L.; Landoas, O.; Thorp, K.; Stoeckl, C.

    2013-12-01

    The interaction of a high intensity laser pulse on the preplasma of a high-Z solid target produced by the pulse's pedestal generates high-energy electrons. These electrons subsequently penetrate inside the solid target and produce bremsstrahlung photons, generating an x-ray source which can be used for photonuclear studies or to radiograph high area density objects. The source characteristics are compared for targets with thin (20 μm) and thick (100 μm) Au foils on the Omega EP laser at Laboratory for Laser Energetics. Simulations using the particle-in-cell code CALDER show that for a 20 μm thickness Au target, electrons perform multiple round-trips in the target under the effect of the laser ponderomotive potential and the target electrostatic potential. These relativistic electrons have random transverse displacements, with respect to the target normal, attributed to electrostatic fluctuation fields. As a result, the x-ray spot size is increased by a factor 2 for thin target compared to thick targets, in agreement with experimental results. In addition, the computed doses agree with the measured ones provided that electron recirculation in the thin target is taken into account. A dose increase by a factor 1.7 is then computed by allowing for recirculation. In the 100 μm target case, on the other hand, this effect is found to be negligible.

  12. P3: An installation for high-energy density plasma physics and ultra-high intensity laser–matter interaction at ELI-Beamlines

    Directory of Open Access Journals (Sweden)

    S. Weber

    2017-07-01

    Full Text Available ELI-Beamlines (ELI-BL, one of the three pillars of the Extreme Light Infrastructure endeavour, will be in a unique position to perform research in high-energy-density-physics (HEDP, plasma physics and ultra-high intensity (UHI (>1022W/cm2 laser–plasma interaction. Recently the need for HED laboratory physics was identified and the P3 (plasma physics platform installation under construction in ELI-BL will be an answer. The ELI-BL 10 PW laser makes possible fundamental research topics from high-field physics to new extreme states of matter such as radiation-dominated ones, high-pressure quantum ones, warm dense matter (WDM and ultra-relativistic plasmas. HEDP is of fundamental importance for research in the field of laboratory astrophysics and inertial confinement fusion (ICF. Reaching such extreme states of matter now and in the future will depend on the use of plasma optics for amplifying and focusing laser pulses. This article will present the relevant technological infrastructure being built in ELI-BL for HEDP and UHI, and gives a brief overview of some research under way in the field of UHI, laboratory astrophysics, ICF, WDM, and plasma optics.

  13. Parental engagement and early interactions with preterm infants during the stay in the neonatal intensive care unit: protocol of a mixed-method and longitudinal study

    Science.gov (United States)

    Stefana, Alberto; Lavelli, Manuela

    2017-01-01

    Introduction The preterm infants' developmental outcomes depend on biological and environmental risk factors. The environmental factors include prolonged parental separation, less exposure to early mother/father–infant interactions and the parents' ability to respond to the trauma of premature birth. In the case of premature birth, the father's ability to take an active part in the care of the infant from the start is essential. The parents' emotional closeness to the preterm infant hospitalised in the neonatal intensive care unit (NICU) may be crucial to the well-being of the newborn, the development of mutual regulation, the establishment of a functioning parent–infant affective relationship and the parents' confidence in their ability to provide care for their baby. Methods and analysis This is a mixed-method, observational and longitudinal study. The methodological strategy will include: (1) ethnographic observation in a level III NICU located in Italy for a duration of 18 months; (2) 3-minute video recordings of mother–infant and father–infant interaction in the NICU; (3) a semistructured interview with fathers during the infants' hospital stay; (4) 3-minute video recordings of mother–infant and father–infant face-to-face interaction in the laboratory at 4 months of corrected age; (5) self-report questionnaires for parents on depression and quality of the couple relationship at the approximate times of the video recording sessions. Ethics and dissemination The study protocol was approved by the Ethical Committee for Clinical Trials of the Verona and Rovigo Provinces. Results aim to be published in international peer-reviewed journals, and presented at relevant national and international conferences. This research project will develop research relevant to (1) the quality and modalities of maternal and paternal communication with the preterm infant in the NICU; (2) the influence of maternal/paternal social stimulation on the infant behavioural

  14. Parental engagement and early interactions with preterm infants during the stay in the neonatal intensive care unit: protocol of a mixed-method and longitudinal study.

    Science.gov (United States)

    Stefana, Alberto; Lavelli, Manuela

    2017-02-02

    The preterm infants' developmental outcomes depend on biological and environmental risk factors. The environmental factors include prolonged parental separation, less exposure to early mother/father-infant interactions and the parents' ability to respond to the trauma of premature birth. In the case of premature birth, the father's ability to take an active part in the care of the infant from the start is essential. The parents' emotional closeness to the preterm infant hospitalised in the neonatal intensive care unit (NICU) may be crucial to the well-being of the newborn, the development of mutual regulation, the establishment of a functioning parent-infant affective relationship and the parents' confidence in their ability to provide care for their baby. This is a mixed-method, observational and longitudinal study. The methodological strategy will include: (1) ethnographic observation in a level III NICU located in Italy for a duration of 18 months; (2) 3-minute video recordings of mother-infant and father-infant interaction in the NICU; (3) a semistructured interview with fathers during the infants' hospital stay; (4) 3-minute video recordings of mother-infant and father-infant face-to-face interaction in the laboratory at 4 months of corrected age; (5) self-report questionnaires for parents on depression and quality of the couple relationship at the approximate times of the video recording sessions. The study protocol was approved by the Ethical Committee for Clinical Trials of the Verona and Rovigo Provinces. Results aim to be published in international peer-reviewed journals, and presented at relevant national and international conferences. This research project will develop research relevant to (1) the quality and modalities of maternal and paternal communication with the preterm infant in the NICU; (2) the influence of maternal/paternal social stimulation on the infant behavioural states; (3) the quality and modalities of paternal support to the partner

  15. Broadband Brillouin scatter from CO/sub 2/-laser--target interactions

    Energy Technology Data Exchange (ETDEWEB)

    Mitchel, G.R.; Grek, B.; Johnston, T.W.; Pepin, H.; Church, P.; Lavigne, P.; Martin, F.; Decoste, R.

    1982-05-24

    Light scattered near the incident wavelength from CO/sub 2/ laser--solid target interactions in oblique incidence shows the spectral signature of Brillouin scattering both in the backward and in the near specular directions. This instability is apparently seeded by broadband scatter from the critical density surface and then amplified in the underdense plasma. 60% of the incident light is scattered, and the Brillouin contribution to total scatter may be large if the source is also large.

  16. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions...... interaction between a human operator and an artificial actor or agent. We can apply insights from puppetry to develop culturally-aware robots. Here we describe the development of a robotic marionette theatre wherein robotic controllers assume the role of human puppeteers. The system has been built, tested...

  17. Interactions

    DEFF Research Database (Denmark)

    The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists...... such as Lorentz and Einstein as well as mathematicians such as Poincare, Minkowski, Hilbert and Weyl contributed to this development. They created the new physical theories and the mathematical disciplines that play such paramount roles in their mathematical formulations. These physicists and mathematicians were...

  18. Sound Intensity

    DEFF Research Database (Denmark)

    Crocker, M.J.; Jacobsen, Finn

    1997-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  19. Sound Intensity

    DEFF Research Database (Denmark)

    Crocker, M.J.; Jacobsen, Finn

    1997-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  20. Sound intensity

    DEFF Research Database (Denmark)

    Crocker, Malcolm J.; Jacobsen, Finn

    1998-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  1. Generation and transport of fast electrons in the interaction of high intensity laser with matter; Generation et transport des electrons rapides dans l'interaction laser-matiere a haut flux

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, H

    2005-10-15

    The general context of this study is the Inertial Confinement for thermonuclear controlled fusion and, more precisely, the Fast Igniter (FI). In this context the knowledge of the generation and transport of fast electrons is crucial. This thesis is an experimental study of the generation and transport of fast electrons in the interaction of a high intensity laser ({>=} 10{sup 19} W/cm{sup 2}) with a solid target. The main diagnostic used here is the transition radiation. This radiation depends on the electrons which produce it and thus it gives important information on the electrons: energy, temperature, propagation geometry, etc. The spectral, temporal and spatial analysis permitted to put in evidence the acceleration of periodic electron bunches which, in this case, emit a Coherent Transition Radiation (CTR). During this thesis we have developed some theoretical models in order to explain the experimental results. We find this way two kinds of electron bunches, emitted either at the laser frequency ({omega}{sub 0}), either at the double of this frequency (2{omega}{sub 0}), involving several acceleration mechanisms: vacuum heating / resonance absorption and Lorentz force, respectively. These bunches are also observed in the PIC (particle-in-cell) simulations. The electron temperature is of about 2 MeV in our experimental conditions. The electrons are emitted starting from a point source (which is the laser focal spot) and then propagate in a ballistic way through the target. In some cases they can be re-injected in the target by the electrostatic field from the target edges. This diagnostic is only sensitive to the coherent relativistic electrons, which explains the weak total energy that they contain (about a few mJ). The CTR signal emitted by those fast electrons is largely dominating the signal emitted by the less energetic electrons, even if they contain the major part of the energy (about 1 J). (author)

  2. Interaction of argon clusters with intense VUV-laser radiation: the role of electronic structure in the energy-deposition process.

    Science.gov (United States)

    Laarmann, T; De Castro, A R B; Gürtler, P; Laasch, W; Schulz, J; Wabnitz, H; Möller, T

    2004-04-09

    The response of Ar clusters to intense vacuum-ultraviolet pulses is investigated with photoion spec-troscopy. By varying the laser wavelength, the initial excitation was either tuned to absorption bands of surface or bulk atoms of clusters. Multiple ionization is observed, which leads to Coulomb explosion. The efficiency of resonant 2-photon ionization for initial bulk and surface excitation is compared with that of the nonresonant process at different laser intensities. The specific electronic structure of clusters plays almost no role in the explosion dynamics at a peak intensity larger than 1.8 x 10(12) W/cm(2). The inner ionization of atoms for resonant and nonresonant excitation is then saturated and the energy deposition is mainly controlled by the plasma heating rate. Molecular dynamics simulations indicate that standard collisional heating cannot fully account for the strong energy absorption.

  3. Depletion of intense fields

    CERN Document Server

    Seipt, D; Marklund, M; Bulanov, S S

    2016-01-01

    The interaction of charged particles and photons with intense electromagnetic fields gives rise to multi-photon Compton and Breit-Wheeler processes. These are usually described in the framework of the external field approximation, where the electromagnetic field is assumed to have infinite energy. However, the multi-photon nature of these processes implies the absorption of a significant number of photons, which scales as the external field amplitude cubed. As a result, the interaction of a highly charged electron bunch with an intense laser pulse can lead to significant depletion of the laser pulse energy, thus rendering the external field approximation invalid. We provide relevant estimates for this depletion and find it to become important in the interaction between fields of amplitude $a_0 \\sim 10^3$ and electron bunches with charges of the order of nC.

  4. Depletion of Intense Fields

    Science.gov (United States)

    Seipt, D.; Heinzl, T.; Marklund, M.; Bulanov, S. S.

    2017-04-01

    The interaction of charged particles and photons with intense electromagnetic fields gives rise to multiphoton Compton and Breit-Wheeler processes. These are usually described in the framework of the external field approximation, where the electromagnetic field is assumed to have infinite energy. However, the multiphoton nature of these processes implies the absorption of a significant number of photons, which scales as the external field amplitude cubed. As a result, the interaction of a highly charged electron bunch with an intense laser pulse can lead to significant depletion of the laser pulse energy, thus rendering the external field approximation invalid. We provide relevant estimates for this depletion and find it to become important in the interaction between fields of amplitude a0˜1 03 and electron bunches with charges of the order of 10 nC.

  5. Interactions of carbon and nitrogen metabolism with changing light intensity in natural populations and cultures of planktonic blue-green algae

    Energy Technology Data Exchange (ETDEWEB)

    Ward, A.K.

    1978-01-01

    This study dealt with the factors contributing to the occurrence of blue-green algae in the plankton of lakes. Blue-green algal populations were examined in two different aquatic systems, moderately productive Lawrence Lake and hypereutrophic Wintergreen Lake, with regard to inorganic nitrogen source, light intensity and regime, and species of blue-green algae present. In order to understand the relationship between light and nitrogen source better among natural populations, representative species of blue-green algae, including isolates of Aphanizomenon flos-aquae, Microcystis aeruginosa, and Anabaena flos-aquae, were grown in laboratory cultures under continuously high, variable, and continuously low light at intensities similar to those in the lakes.

  6. Theory of two-electron atoms interacting with intense laser pulses: the one-photon ionization of He and the photodetachment of H{sup -}

    Energy Technology Data Exchange (ETDEWEB)

    Abrashkevich, A.G.; Shapiro, M. [Weizmann Inst. of Science, Rehovoth (Israel). Dept. of Chemical Physics and Structural Chemistry

    1996-02-28

    Theory of one-photon ionization of atoms by intense light pulses is developed. The infinite set of coupled first-order differential equations, derived from the time-dependent Schroedinger equation, is reduced to a single integro-differential equation. This equation is solved both numerically and in closed form by invoking the slowly varying continuum approximation (SVCA). Comparisons of the SVCA with the numerical solutions are used to delimit the range of validity of this approximation. The time-evolution of wavepackets composed of scattering states prepared by short laser pulses is studied as a function of the pulse intensity. We predict a transient `freezing` of the wavepacket during its build-up phase. Temporal saturation and power broadening of the wavepacket by the strong field are also studied. Our method is used to performing exact numerical calculations of the real-time strong-pulse one-photon ionization of He and the photodetachment of H{sup -}. (author).

  7. The intense neutron generator

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W.B

    1966-07-01

    The presentation discusses both the economic and research contexts that would be served by producing neutrons in gram quantities at high intensities by electrical means without uranium-235. The revenue from producing radioisotopes is attractive. The array of techniques introduced by the multipurpose 65 megawatt Intense Neutron Generator project includes liquid metal cooling, superconducting magnets for beam bending and focussing, super-conductors for low-loss high-power radiofrequency systems, efficient devices for producing radiofrequency power, plasma physics developments for producing and accelerating hydrogen, ions at high intensity that are still far out from established practice, a multimegawatt high voltage D.C. generating machine that could have several applications. The research fields served relate principally to materials science through neutron-phonon and other quantum interactions as well as through neutron diffraction. Nuclear physics is served through {mu}-, {pi}- and K-meson production. Isotope production enters many fields of applied research. (author)

  8. A randomized controlled trial evaluating a low-intensity interactive online parenting intervention, Triple P Online Brief, with parents of children with early onset conduct problems.

    Science.gov (United States)

    Baker, Sabine; Sanders, Matthew R; Turner, Karen M T; Morawska, Alina

    2017-04-01

    This randomized controlled trial examined the efficacy of Triple P Online Brief, a low-intensity online positive parenting program for parents of children with early onset disruptive behavior problems. Two hundred parents with 2-9-year-old children displaying early onset disruptive behavior difficulties were randomly assigned to either the intervention condition (n = 100) or a Waitlist Control group (n = 100). At 8-week post-assessment, parents in the intervention group displayed significantly less use of ineffective parenting strategies and significantly more confidence in dealing with a range of behavior concerns. These effects were maintained at 9-month follow-up assessment. A delayed effect was found for child behavior problems, with parents in the intervention group reporting significantly fewer and less frequent child behavior problems at follow-up, but not at post-assessment. All effect sizes were in the small to medium range. There were no significant improvements in observed negative parent and child behavior. No change was seen for parents' adjustment, anger, or conflict over parenting. Consumer satisfaction ratings for the program were high. A brief, low-intensity parenting program delivered via the Internet can bring about significant improvements in parenting and child behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Theory of two-electron atoms interacting with intense laser pulses: the one-photon ionization of He and the photodetachment of ?

    Science.gov (United States)

    Abrashkevich, Alexander G.; Shapiro, Moshe

    1996-02-01

    Theory of one-photon ionization of atoms by intense light pulses is developed. The infinite set of coupled first-order differential equations, derived from the time-dependent Schrödinger equation, is reduced to a single integro-differential equation. This equation is solved both numerically and in closed form by invoking the slowly varying continuum approximation (SVCA). Comparisons of the SVCA with the numerical solutions are used to delimit the range of validity of this approximation. The time-evolution of wavepackets composed of scattering states prepared by short laser pulses is studied as a function of the pulse intensity. We predict a transient `freezing' of the wavepacket during its build-up phase. Temporal saturation and power broadening of the wavepacket by the strong field are also studied. Our method is used to performing exact numerical calculations of the real-time strong-pulse one-photon ionization of He and the photodetachment of 0953-4075/29/4/006/img2.

  10. Intensive mobilities:

    DEFF Research Database (Denmark)

    Vannini, Phillip; Bissell, David; Jensen, Ole B.

    This paper explores the intensities of long distance commuting journeys as a way of exploring how bodily sensibilities are being changed by the mobilities that they undertake. The context of this paper is that many people are travelling further to work than ever before owing to a variety of facto....... By exploring how experiences of long-distance workers become constituted by a range of different material forces enables us to more sensitively consider the practical, technical, and political implications of this increasingly prevalent yet underexplored regime of work....... which relate to transport, housing and employment. Yet we argue that the experiential dimensions of long distance mobilities have not received the attention that they deserve within geographical research on mobilities. This paper combines ideas from mobilities research and contemporary social theory...... with fieldwork conducted in Canada, Denmark and Australia to develop our understanding of the experiential politics of long distance workers. Rather than focusing on the extensive dimensions of mobilities that are implicated in patterns and trends, our paper turns to the intensive dimensions of this experience...

  11. Generation of shock fronts in the interaction of short pulses of intense laser light in supercritical plasma; Generacion de frentes de choque en la interaccion de pulsos cortos de luz laser intensa en plasmas supercriticos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez V, V.E. [ITESST, 52650 Estado de Mexico (Mexico); Ondarza R, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    The investigation of the laser interaction with plasma has been carried out mainly in laboratories of Europe, Japan and United States during the last decades. This studies concern the propagation of intense light laser in a non homogeneous plasma, the radiation absorption and the generation of suprathermal electrons, among others. Numerical simulations made by Denavit, for radiation pulses for up of 10{sup 20} W/cm{sup 2} on solid targets, have allowed to observe the generation of ionic crash fronts with high propagation speeds. In this work it is expanded the study of this effect through algorithms of particles simulation. (Author)

  12. Interaction of intense laser fields with metal clusters. Energy absorpion by scattering processes; Wechselwirkung von intensiven Laserfeldern mit Metallclustern. Energieabsorption durch Streuprozesse

    Energy Technology Data Exchange (ETDEWEB)

    Koehn, Joerg

    2010-02-23

    The present thesis aims at the theoretical description of laser-cluster interactions by means of semiclassical simulations, using small sodium clusters as model systems. In particular, the dynamics of ionization and electron emission is analyzed. To this end a model has been developed, which takes the density- and temperature dependence of electron-electron scattering cross sections within the nanoplasma into account. Furthermore the possibility of resonant excitation with few-cycle-pulses and control of the electron emission by means of the carrier-envelope-phase is investigated. (orig.)

  13. Effect of the Initial Laser Phase on the Interaction Between Relativistic Electron and Ultra-Intense Laser Field in a Strong Uniform Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    HE Xin-Kui; SHUAI Bin; GE Xiao-Chun; LI Ru-Xin; XU Zhi-Zhan

    2004-01-01

    @@ We investigate the influence of the initial laser phase on the interaction between relativistic electron and ultraintense linear polarized laser field in a strong uniform magnetic field. It is found that the dynamic behaviour of the relativistic electron and the emission spectrum varies dramatically with different initial laser field phases.The effect of changing initial phase is contrary in the two parameter regions divided by the resonance condition.The phase dependence of the electron energy and velocity components are also studied. Some beat structure is found when the initial laser phase is zero and this structure is absent when the initial laser phase is a quarter of a period.

  14. EFFECT OF LIGHT INTENSITY, TEMPERATURE, TOTAL NITROGEN CONCENTRATION AND THEIR INTERACTION ON HYDRILLA VERTICILLATA%光强、温度、总氮浓度对黑藻生长的影响

    Institute of Scientific and Technical Information of China (English)

    朱丹婷; 乔宁宁; 李铭红; 陈攀

    2011-01-01

    为寻求沉水植物生长的主效环境因子,探求富营养化水体沉水植物的衰亡机理并选择治理富营养化的先锋植物,实验选择长江中下游常见沉水植物种黑藻(Hydrilla verticillata),利用正交试验设计,通过室内静态模拟实验研究三种主要环境因子光照强度、温度、总氮浓度及其互作对黑藻断枝生长的影响.结果表明:光照强度和温度为影响黑藻生长的主效环境因子,并且光强与温度的交互作用对黑藻生长有较为显著的影响,具体表现为黑藻的生长指标(株高、生物量、分枝数)、光合指标(叶绿素a+b浓度、叶绿素a/b、叶绿体总色素含量)和生理活性指标(根活力、可溶性糖含量、MDA含量)的变化均与这两个环境因子及其互作呈显著相关;总氮浓度的变化对黑藻生长影响不大,在2-8 mg/L的总氮浓度下,黑藻均可以正常生长.根据本实验黑藻生长指标、光合色素含量以及生理活性在不同环境因子组合的变化结果可知,黑藻在5320-12000 lx光照强度、20℃-30℃、4-8 mg/L水体总氮浓度的条件下生长良好,故推测黑藻可作为春夏季富营养化水体中恢复和重建沉水植被的先锋工具种.%With the strengthening of freshwater eutrophication, the original aquatic vegetation gradually reduced and even disappeared, resulting in the well-functional grass type water degraded to algae-based water. Submerged plant is a key factor for the construction of stable and well-functioning freshwater ecosystems. Therefore, restoration and reconstruction of submerged plants is very important for prevention and control of eutrophication. The growth and development, decline and extinction of submerged plants are closely related with environmental factors due to their aquatic characteristics. In this study, we aim to explore the effects of light intensity, temperature, total nitrogen concentration and their interactions on the growth and development

  15. Simultaneous high speed digital cinematographic and X-ray radiographic imaging of a intense multi-fluid interaction with rapid phase changes

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, Roberta Concilio; Park, Hyun Sun; Dinh, Truc-Nam [Royal Institute of Technology, Division of Nuclear Power Safety, AlbaNova, Stockholm SE-106 91 (Sweden)

    2009-04-15

    As typical for the study of the vapor explosions, the qualitative and quantitative understanding of the phenomena requires visualization of both material and interface dynamics. A new approach to multi-fluid multiphase visualization is presented with the focus on the development of a synchronized high-speed visualization by digital cinematography and X-ray radiography. The developed system, named SHARP (simultaneous high-speed acquisition of X-ray radiography and photography), and its image processing methodology, directed to an image synchronization procedure and a separate quantification of vapor and molten material dynamics, is presented in this paper. Furthermore, we exploit an intrinsic property of the X-ray radiation, namely the differences in linear mass attenuation coefficients over the beam path through a multi-component system, to characterize the evolution of molten material distribution. Analysis of the data obtained by the SHARP system and image processing procedure developed granted new insights into the physics of the vapor explosion phenomena, as well as, quantitative information of the associated dynamic micro-interactions. (author)

  16. Interaction of low-intensity nuclear radiation dose with the human blood: Using the new technique of CR-39NTDs for an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Asaad H., E-mail: asadhawlery@hotmail.co [Research Group of Radiation and Medical Physics, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Jaafar, Mohamad S. [Research Group of Radiation and Medical Physics, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2011-03-15

    Complete blood counts were analyzed for 30 samples of human blood with radiation dose rate ranging between 10 and 41 {mu}Sv/h using a Radium-226 source with different time of exposure. A new technique involving a nuclear track detector type CR-39(CR-39 NTDs) was used to estimate the alpha particle density incident on the blood samples. The results show that the ranges of alpha particle in blood samples and on the surface of CR-39NTDs vary exponentially with energy of alpha particles. This depends on the restricted energy loss and target density. Changes in the blood components due to irradiation occurred for different durations of irradiation, and the duration of irradiation that influenced the blood samples in this study was 6 min. The change in red blood cell (RBC) was negligible, so it is less affected than other blood components. In addition, most changes in the blood contents began at a low radiation dose (10.38-13.41 {mu}Sv/h). For the doses 13.41-21.77 {mu}Sv/h, platelet (PLT) counts increased rapidly and adversely with the RBC and white blood cell (WBC) due to chromosomal aberration. Besides, rapid PLT count reduction rapidly at high dose (42.1 {mu}Sv h) causes thrombocytopenia; in contrast, WBC increased, which is an indication of cancer caused due to increase in alpha particle dose. Generally, our results are in agreement with the essentials of blood content and the principles of biological radiation interaction.

  17. Hot electron refluxing in the short intense laser pulse interactions with solid targets and its influence on K-α radiation

    Directory of Open Access Journals (Sweden)

    Horný Vojtěch

    2015-06-01

    Full Text Available Fast electrons created as a result of the laser beam interaction with a solid target penetrate into the target material and initialize processes leading to the generation of the characteristic X-ray K-α radiation. Due to the strong electric field induced at the rear side of a thin target the transmitted electrons are redirected back into the target. These refluxing electrons increase the K-α radiation yield, as well as the duration of the X-ray pulse and the size of the radiation emitting area. A model describing the electron refluxing was verified via particle-in-cell simulations for non-relativistic electron energies. Using this model it was confirmed that the effect of the electron refluxing on the generated X-ray radiation depends on the target thickness and the target material. A considarable increase of the number of the emitted K-α photons is observed especially for thin targets made of low-Z materials, and for higher hot electron temperatures.

  18. Computation of energy interaction parameters as well as electric dipole intensity parameters for the absorption spectral study of the interaction of Pr(III) with L-phenylalanine, L-glycine, L-alanine and L-aspartic acid in the presence and absence of Ca 2+ in organic solvents

    Science.gov (United States)

    Moaienla, T.; Singh, Th. David; Singh, N. Rajmuhon; Devi, M. Indira

    2009-10-01

    Studying the absorption difference and comparative absorption spectra of the interaction of Pr(III) and Nd(III) with L-phenylalanine, L-glycine, L-alanine and L-aspartic acid in the presence and absence of Ca 2+ in organic solvents, various energy interaction parameters like Slater-Condon ( FK), Racah ( Ek), Lande factor ( ξ4f), nephelauxetic ratio ( β), bonding ( b1/2), percentage-covalency ( δ) have been evaluated applying partial and multiple regression analysis. The values of oscillator strength ( P) and Judd-Ofelt electric dipole intensity parameter Tλ ( λ = 2, 4, 6) for different 4f-4f transitions have been computed. On analysis of the variation of the various energy interaction parameters as well as the changes in the oscillator strength ( P) and Tλ values reveal the mode of binding with different ligands.

  19. Generation of shock fronts in the interaction of the short pulses of intense laser light in supercritical plasma; Generacion de frentes de choque en la interaccion de pulsos cortos de luz laser intensa en plasmas supercriticos

    Energy Technology Data Exchange (ETDEWEB)

    Lopez V, V.E

    2004-07-01

    The plasma is the state of the matter but diffused in the nature. The sun and the stars big heaps of hot plasma can be considered. The external surface of the terrestrial atmosphere this recovered by a layer of plasma. All gassy discharge (lightning spark arch etc.) this related with the formation of plasma. This way, 99 percent of our environment this formed almost of plasma. It is denominated plasma to the ionized gas in the one which all or most of the atoms have lost one or several of the electrons that belonged him, becoming positive ions and free electrons. In the plasma certain physical characteristics exist as for their behavior like they are the collective movements the quasi neutrality, the Debye length, the uncertainty etc. All these behaviors make that the study of the plasma is complex. For this they exist technical of numeric simulation joined to the technological advance of big computers of more capacity and prosecution speed. The simulation techniques of particles are those where a numeric code is built based on a model or theory of a system that it is wanted to investigate. This way through the simulation the results are compared with those theoretical predictions based on an analytic model. The applications of the physics of the plasma are multiple however we focus ourselves in the interaction laser-plasma. Both finish decades of investigation in the interaction of lasers with plasma they have been carried out in laboratories of Europe, Japan, United States. This studies concern the propagation of intense light laser in dense plasma homogeneous, the radiation absorption in cold plasma and problems related with the generation of suprathermal electrons among others. Other areas of the physics of the plasma-laser interaction that it has been considerable attention is the broadly well-known field as parametric uncertainties induced instabilities by the light and that they include the dispersions for example stimulated Raman and Brillouin being able to

  20. A numerical study of time-dependent Schrödinger equation for multiphoton vibrational interaction of NO molecule, modelled as Morse oscillator, with intense far-infrared femtosecond lasers

    Indian Academy of Sciences (India)

    Amita Wadehra; B M Deb

    2003-10-01

    For the NO molecule, modelled as a Morse oscillator, time-dependent (TD) nuclear Schrödinger equation has been numerically solved for the multiphoton vibrational dynamics of the molecule under a far-infrared laser of wavelength 10503 nm, and four different intensities, = 1 × 108, 1 × 1013, 5 × 1016, and 5 × 1018W cm-2 respectively. Starting from the vibrational ground state at zero time, various TD quantities such as the norm, dissociation probability, potential energy curve and dipole moment are examined. Rich high-harmonics generation (HHG) spectra and above-threshold dissociation (ATD) spectra, due to the multiphoton interaction of vibrational motions with the laser field, and consequent elevation to the vibrational continuum, have been obtained and analysed.

  1. Measuring Physical Activity Intensity

    Science.gov (United States)

    ... aerobic activity: relative intensity and absolute intensity. Relative Intensity The level of effort required by a person to do an activity. When using relative intensity, people pay attention to how physical activity affects ...

  2. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... aerobic activity: relative intensity and absolute intensity. Relative Intensity The level of effort required by a person to do an activity. When using relative intensity, people pay attention to how physical activity affects ...

  3. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... Compartir For more help with what counts as aerobic activity, watch this video: Windows Media Player, 4: ... ways to understand and measure the intensity of aerobic activity: relative intensity and absolute intensity. Relative Intensity ...

  4. Molecular near-field antenna effect in resonance hyper-Raman scattering: Intermolecular vibronic intensity borrowing of solvent from solute through dipole-dipole and dipole-quadrupole interactions

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Rintaro; Hamaguchi, Hiro-o, E-mail: hhama@nctu.edu.tw [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan (China)

    2014-05-28

    We quantitatively interpret the recently discovered intriguing phenomenon related to resonance Hyper-Raman (HR) scattering. In resonance HR spectra of all-trans-β-carotene (β-carotene) in solution, vibrations of proximate solvent molecules are observed concomitantly with the solute β-carotene HR bands. It has been shown that these solvent bands are subject to marked intensity enhancements by more than 5 orders of magnitude under the presence of β-carotene. We have called this phenomenon the molecular-near field effect. Resonance HR spectra of β-carotene in benzene, deuterated benzene, cyclohexane, and deuterated cyclohexane have been measured precisely for a quantitative analysis of this effect. The assignments of the observed peaks are made by referring to the infrared, Raman, and HR spectra of neat solvents. It has been revealed that infrared active and some Raman active vibrations are active in the HR molecular near-field effect. The observed spectra in the form of difference spectra (between benzene/deuterated benzene and cyclohexane/deuterated cyclohexane) are quantitatively analyzed on the basis of the extended vibronic theory of resonance HR scattering. The theory incorporates the coupling of excited electronic states of β-carotene with the vibrations of a proximate solvent molecule through solute–solvent dipole–dipole and dipole–quadrupole interactions. It is shown that the infrared active modes arise from the dipole–dipole interaction, whereas Raman active modes from the dipole–quadrupole interaction. It is also shown that vibrations that give strongly polarized Raman bands are weak in the HR molecular near-field effect. The observed solvent HR spectra are simulated with the help of quantum chemical calculations for various orientations and distances of a solvent molecule with respect to the solute. The observed spectra are best simulated with random orientations of the solvent molecule at an intermolecular distance of 10 Å.

  5. Calculation and Comparison of Energy Interaction and Intensity Parameters for the Interaction of Nd(III with DL-Valine, DL-Alanine and β-Alanine in Presence and Absence of Ca2+/Zn2+ in Aqueous and Different Aquated Organic Solvents Using 4f-4f Transition Spectra as Probe

    Directory of Open Access Journals (Sweden)

    H. Debecca Devi

    2009-01-01

    Full Text Available Absorption difference and comparative absorption spectrophotometric studies involving 4f-4f transitions of Nd(III and different amino acids: DL-valine, DL-alanine, and β-alanine in presence and absence of Ca(II and Zn(II in aqueous and different aquated organic solvents have been carried out. Variations in the spectral energy parameters: Slater-Condon (FK factor, Racah (EK, Lande factor (ξ4f, nephelauxetic ratio (β, bonding (b1/2, percentage covalency (δ are calculated to explore the mode of interaction of Nd(III with different amino acids: DL-valine, DL-alanine, and β-alanine. The values of experimentally calculated oscillator strength (P and computed values of Judd-Ofelt electric dipole intensity parameters, Tλ (λ = 2,4,6, are also determined for different 4f-4f transitions. The variation in the values of P and Tλ parameters explicitly shows the relative sensitivities of the 4f-4f transitions as well as the specific correlation between relative intensities, ligand structures, and nature of Nd(III-ligand interaction.

  6. Iowa Intensive Archaeological Survey

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This shape file contains intensive level archaeological survey areas for the state of Iowa. All intensive Phase I surveys that are submitted to the State Historic...

  7. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... for a breath. Absolute Intensity The amount of energy used by the body per minute of activity. ... or vigorous-intensity based upon the amount of energy used by the body while doing the activity. ...

  8. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... Older Adults Overcoming Barriers Measuring Physical Activity Intensity Target Heart Rate & Estimated Maximum Heart Rate Perceived Exertion ( ... a heavy backpack Other Methods of Measuring Intensity Target Heart Rate and Estimated Maximum Heart Rate Perceived ...

  9. Rainfed intensive crop systems

    DEFF Research Database (Denmark)

    Olesen, Jørgen E

    2014-01-01

    This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed.......This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed....

  10. Midbrain local circuits shape sound intensity codes.

    Science.gov (United States)

    Grimsley, Calum Alex; Sanchez, Jason Tait; Sivaramakrishnan, Shobhana

    2013-01-01

    Hierarchical processing of sensory information requires interaction at multiple levels along the peripheral to central pathway. Recent evidence suggests that interaction between driving and modulating components can shape both top down and bottom up processing of sensory information. Here we show that a component inherited from extrinsic sources combines with local components to code sound intensity. By applying high concentrations of divalent cations to neurons in the nucleus of the inferior colliculus in the auditory midbrain, we show that as sound intensity increases, the source of synaptic efficacy changes from inherited inputs to local circuits. In neurons with a wide dynamic range response to intensity, inherited inputs increase firing rates at low sound intensities but saturate at mid-to-high intensities. Local circuits activate at high sound intensities and widen dynamic range by continuously increasing their output gain with intensity. Inherited inputs are necessary and sufficient to evoke tuned responses, however local circuits change peak output. Push-pull driving inhibition and excitation create net excitatory drive to intensity-variant neurons and tune neurons to intensity. Our results reveal that dynamic range and tuning re-emerge in the auditory midbrain through local circuits that are themselves variable or tuned.

  11. Intensity Frontier Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Kettell S.; Rameika, R.; Tshirhart, B.

    2013-09-24

    The fundamental origin of flavor in the Standard Model (SM) remains a mystery. Despite the roughly eighty years since Rabi asked “Who ordered that?” upon learning of the discovery of the muon, we have not understood the reason that there are three generations or, more recently, why the quark and neutrino mixing matrices and masses are so different. The solution to the flavor problem would give profound insights into physics beyond the Standard Model (BSM) and tell us about the couplings and the mass scale at which the next level of insight can be found. The SM fails to explain all observed phenomena: new interactions and yet unseen particles must exist. They may manifest themselves by causing SM reactions to differ from often very precise predictions. The Intensity Frontier (1) explores these fundamental questions by searching for new physics in extremely rare processes or those forbidden in the SM. This often requires massive and/or extremely finely tuned detectors.

  12. Relativistic motion of charged particles in the interaction of short pulses of intense laser light with plasma; Movimiento relativista de particulas cargadas en la interaccion de pulsos cortos de luz laser intensa con plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gomez R, F

    2004-07-01

    oscillations free of the electrons in the plasma. These oscillations, calls of Langmuir, its are produced by the present electric field in the electrically neuter plasma when it is produced any deviation of the space distribution of the electrons takes place regarding that of the equilibrium. An analytical theory for the case of a particle in a plasma, which decreases to the one described in the chapter 4 is studied. It will see that in a dense plasma the movement of the electrons produces strong interactions, which modify the dynamics of the electron and the propagation of the pulse. These effects will be analyzed by means of simulations in which a single particle intervenes and where the space-charge effects will be represented by means of a vectorial potential. In this calculation the effects of the movement of the electron on the propagation of the laser its will be rejected. Our results will be compare with those reported by Bardsley et al. and the excellent approaches obtained will be shown. To carry out the analytical compute in the calculations, atomic units (u a) are introduced, which are more appropriate for this type of study. For the interpretation of the numerical results it will be convenient to carry out certain analytical calculations. Diagrams of trajectory where the electron is initially in repose, and where the maximum amplitude of the electric field will be of 100 u a (5,14 x 10{sup 11} V/cm), corresponding to an intensity of pulse of 3,5 x 10{sup 20} W/cm{sup 2} and to an optical frequency of {omega} = 0,18 u a, of a KrF laser will be present. The final part will dedicate it to the presentation and interpretation of our results, as well as the perspectives and research lines opened up around the studied problem. In the last part of this work its put on all the bibliographical references that have been consulted for the realization of this work. (Author)

  13. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... Adults Overcoming Barriers Measuring Physical Activity Intensity Target Heart Rate & Estimated Maximum Heart Rate Perceived Exertion (Borg Rating of Perceived Exertion Scale) ...

  14. Laser-surface interactions

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    This book is about the interaction of laser radiation with various surfaces at variable parameters of radiation. As a basic principle of classification we chose the energetic or intensity level of interaction of laser radiation with the surfaces. These two characteristics of laser radiation are the most important parameters defining entire spectrum of the processes occurring on the surfaces during interaction with electromagnetic waves. This is a first book containing a whole spectrum of the laser-surface interactions distinguished by the ranges of used laser intensity. It combines the surface response starting from extremely weak laser intensities (~1 W cm-2) up to the relativistic intensities (~1020 W cm-2 and higher). The book provides the basic information about lasers and acquaints the reader with both common applications of laser-surface interactions (laser-related printers, scanners, barcode readers, discs, material processing, military, holography, medicine, etc) and unusual uses of the processes on t...

  15. Interação medicamentosa: conhecimento de enfermeiros das unidades de terapia intensiva Interacción medicamentosa: conocimiento de enfermeros de las unidades de cuidados intensivos Medication interaction: knowledge of nurses in intensive care units

    Directory of Open Access Journals (Sweden)

    Leila Márcia Pereira de Faria

    2011-01-01

    Full Text Available OBJETIVO: Avaliar o conhecimento das interações medicamentosas (IMde enfermeiros que atuam em unidades de terapia intensiva de adultos, de três hospitais públicos de Goiás. MÉTODOS: Estudo descritivo, transversal. População 64 e amostra, 51 enfermeiros. Construiu-se um instrumento de coleta de dados, utilizando informações da base de dados MICROMEDEX®. RESULTADOS: Sobre o conhecimento de IM e manejo clínico, houve uma relação de acertos e erros de, aproximadamente, 50% dos enfermeiros. As duplas de medicamentos que os enfermeiros mais acertaram foram relativas a medicamentos com ação sedativa e analgésica e as que apresentaram mais erros, foram as de ação anti-infecciosa e anti-hipertensiva. CONCLUSÃO: É necessário sensibilizar autoridades e profissionais sobre a importância das IM na UTI e implementar ações para a segurança dos pacientes na terapêutica medicamentosa.OBJETIVO: Evaluar el conocimiento de las interacciones medicamentosas (IM de enfermeros que actúan en unidades de cuidados intensivos de adultos, de tres hospitales públicos de Goiás. MÉTODOS: Estudio descriptivo, transversal. Población 64 y muestra 51 enfermeros. Se construyó un instrumento de recolección de datos, utilizando informaciones de la base de datos MICROMEDEX®. RESULTADOS: Sobre el conocimiento de IM y manejo clínico, hubo una relación de aciertos y errores de, aproximadamente el 50% de los enfermeros. El par de medicamentos que los enfermeros aciertan más fueron los relativos a medicamentos con acción sedante y analgésica y los que presentaron más errores, fueron los de acción anti-infecciosa y anti-hipertensiva. CONCLUSIÓN: Es necesario sensibilizar a las autoridades y profesionales sobre la importancia de las IM en la UCI e implementar acciones para la seguridad de los pacientes en la terapéutica medicamentosa.OBJECTIVE: To evaluate adult intensive care unit (ICU nurses' knowledge of medication interactions (IM in three

  16. Pediatric intensive care.

    Science.gov (United States)

    Macintire, D K

    1999-07-01

    To provide optimal care, a veterinarian in a pediatric intensive care situation for a puppy or kitten should be familiar with normal and abnormal vital signs, nursing care and monitoring considerations, and probable diseases. This article is a brief discussion of the pediatric intensive care commonly required to treat puppies or kittens in emergency situations and for canine parvovirus type 2 enteritis.

  17. Analysis and simulation of XPM intensity modulation

    Institute of Scientific and Technical Information of China (English)

    Jing Huang; Jianquan Yao

    2005-01-01

    Based on the split-step Fourier method and small signal analysis, an improved analytical solution which describes the cross-phase modulation (XPM) intensity is derived. It can suppress the spurious XPM intensity modulation efficiently in the whole transmission fiber. Thus it is more coincidence with the practical result. Furthermore, it is convenient, because it is independent of channel separation and the dispersion and nonlinear effects interact through the XPM intensity. A criterion of select the step size is described as the derived XPM intensity modulation being taken into account. It is non-uniform distribution method, the simulation accuracy is improved when the step size is determined by the improved XPM intensity.

  18. Intensity Biased PSP Measurement

    Science.gov (United States)

    Subramanian, Chelakara S.; Amer, Tahani R.; Oglesby, Donald M.; Burkett, Cecil G., Jr.

    2000-01-01

    The current pressure sensitive paint (PSP) technique assumes a linear relationship (Stern-Volmer Equation) between intensity ratio (I(sub o)/I) and pressure ratio (P/P(sub o)) over a wide range of pressures (vacuum to ambient or higher). Although this may be valid for some PSPs, in most PSPs the relationship is nonlinear, particularly at low pressures (less than 0.2 psia when the oxygen level is low). This non-linearity can be attributed to variations in the oxygen quenching (de-activation) rates (which otherwise is assumed constant) at these pressures. Other studies suggest that some paints also have non-linear calibrations at high pressures; because of heterogeneous (non-uniform) oxygen diffusion and quenching. Moreover, pressure sensitive paints require correction for the output intensity due to light intensity variation, paint coating variation, model dynamics, wind-off reference pressure variation, and temperature sensitivity. Therefore to minimize the measurement uncertainties due to these causes, an insitu intensity correction method was developed. A non-oxygen quenched paint (which provides a constant intensity at all pressures, called non-pressure sensitive paint, NPSP) was used for the reference intensity (I(sub NPSP) with respect to which all the PSP intensities (I) were measured. The results of this study show that in order to fully reap the benefits of this technique, a totally oxygen impermeable NPSP must be available.

  19. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... rate and breathing. The talk test is a simple way to measure relative intensity. In general, if ... Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs File Formats Help: How do I view different ...

  20. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... Button Our Division About Us Nutrition Physical Activity Overweight & Obesity Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Measuring Physical Activity Intensity Recommend on Facebook Tweet Share Compartir For ...

  1. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... energy used by the body while doing the activity. Top of Page Moderate Intensity Walking briskly (3 miles per hour or faster, but not race-walking) Water aerobics Bicycling slower than 10 miles per hour ...

  2. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... Measuring Intensity Target Heart Rate and Estimated Maximum Heart Rate Perceived Exertion (Borg Rating of Perceived Exertion Scale) Get Email Updates To receive email updates about this page, enter your ... ...

  3. Measuring Physical Activity Intensity

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    Full Text Available ... per hour or faster, but not race-walking) Water aerobics Bicycling slower than 10 miles per hour Tennis (doubles) Ballroom dancing General gardening Vigorous Intensity Race walking, jogging, or running Swimming ...

  4. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... Measuring Intensity Target Heart Rate and Estimated Maximum Heart Rate Perceived Exertion (Borg Rating of Perceived Exertion Scale) Get Email Updates To receive email updates about this page, enter your email ... ...

  5. Measuring Physical Activity Intensity

    Medline Plus

    Full Text Available ... be able to say more than a few words without pausing for a breath. Absolute Intensity The ... per hour or faster, but not race-walking) Water aerobics Bicycling slower than 10 miles per hour ...

  6. Measuring Physical Activity Intensity

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    Full Text Available ... be able to say more than a few words without pausing for a breath. Absolute Intensity The ... site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel file Audio/Video file Apple ...

  7. Measuring Physical Activity Intensity

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    Full Text Available ... Adults Needs for Children What Counts Needs for Older Adults Needs for Pregnant or Postpartum Women Physical Activity & ... to Your Life Activities for Children Activities for Older Adults Overcoming Barriers Measuring Physical Activity Intensity Target Heart ...

  8. [Intensive medicine in Spain].

    Science.gov (United States)

    2011-03-01

    Intensive care medicine is a medical specialty that was officially established in our country in 1978, with a 5-year training program including two years of common core training followed by three years of specific training in an intensive care unit accredited for training. During this 32-year period, intensive care medicine has carried out an intense and varied activity, which has allowed its positioning as an attractive and with future specialty in the hospital setting. This document summarizes the history of the specialty, its current situation, the key role played in the programs of organ donation and transplantation of the National Transplant Organization (after more than 20 years of mutual collaboration), its training activities with the development of the National Plan of Cardiopulmonary Resuscitation, with a trajectory of more than 25 years, its interest in providing care based on quality and safety programs for the severely ill patient. It also describes the development of reference registries due to the need for reliable data on the care process for the most prevalent diseases, such as ischemic heart disease or ICU-acquired infections, based on long-term experience (more than 15 years), which results in the availability of epidemiological information and characteristics of care that may affect the practical patient's care. Moreover, features of its scientific society (SEMICYUC) are reported, an organization that agglutinates the interests of more than 280 ICUs and more than 2700 intensivists, with reference to the journal Medicina Intensiva, the official journal of the society and the Panamerican and Iberian Federation of Critical Medicine and Intensive Care Societies. Medicina Intensiva is indexed in the Thompson Reuters products of Science Citation Index Expanded (Scisearch(®)) and Journal Citation Reports, Science Edition. The important contribution of the Spanish intensive care medicine to the scientific community is also analyzed, and in relation to

  9. Data-intensive science

    CERN Document Server

    Critchlow, Terence

    2013-01-01

    Data-intensive science has the potential to transform scientific research and quickly translate scientific progress into complete solutions, policies, and economic success. But this collaborative science is still lacking the effective access and exchange of knowledge among scientists, researchers, and policy makers across a range of disciplines. Bringing together leaders from multiple scientific disciplines, Data-Intensive Science shows how a comprehensive integration of various techniques and technological advances can effectively harness the vast amount of data being generated and significan

  10. Towards higher intensities

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Over the past 2 weeks, commissioning of the machine protection system has advanced significantly, opening up the possibility of higher intensity collisions at 3.5 TeV. The intensity has been increased from 2 bunches of 1010 protons to 6 bunches of 2x1010 protons. Luminosities of 6x1028 cm-2s-1 have been achieved at the start of fills, a factor of 60 higher than those provided for the first collisions on 30 March.   The recent increase in LHC luminosity as recorded by the experiments. (Graph courtesy of the experiments and M. Ferro-Luzzi) To increase the luminosity further, the commissioning crews are now trying to push up the intensity of the individual proton bunches. After the successful injection of nominal intensity bunches containing 1.1x1011 protons, collisions were subsequently achieved at 450 GeV with these intensities. However, half-way through the first ramping of these nominal intensity bunches to 3.5 TeV on 15 May, a beam instability was observed, leading to partial beam loss...

  11. Detecting radiation reaction at moderate laser intensities.

    Science.gov (United States)

    Heinzl, Thomas; Harvey, Chris; Ilderton, Anton; Marklund, Mattias; Bulanov, Stepan S; Rykovanov, Sergey; Schroeder, Carl B; Esarey, Eric; Leemans, Wim P

    2015-02-01

    We propose a new method of detecting radiation reaction effects in the motion of particles subjected to laser pulses of moderate intensity and long duration. The effect becomes sizable for particles that gain almost no energy through the interaction with the laser pulse. Hence, there are regions of parameter space in which radiation reaction is actually the dominant influence on charged particle motion.

  12. Requirements Analysis for Information-Intensive Systems

    Science.gov (United States)

    Callender, E. D.; Hartsough, C.; Morris, R. V.; Yamamoto, Y.

    1986-01-01

    Report discusses role of requirements analysis in development of information-intensive systems. System examined from variety of human viewpoints during design, development, and implementation. Such examination, called requirements analysis, ensures system simultaneously meets number of distinct but interacting needs. Viewpoints defined and integrated to help attain objectives.

  13. Stimulated Raman backscattering at high laser intensities

    Energy Technology Data Exchange (ETDEWEB)

    Skoric, M.M. [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Tajima, Toshiki; Sasaki, Akira; Maluckov, A.; Jovanovic, M.

    1998-03-01

    Signatures of Stimulated Raman backscattering of a short-pulse high-intensity laser interacting with an underdense plasma are discussed. We introduce a nonlinear three-wave interaction model that accounts for laser pump depletion and relativistic detuning. A mechanism is revealed based on a generic route to chaos, that predicts a progressive increase of the backscatter complexity with a growing laser intensity. Importance of kinetic effects is outlined and demonstrated in fluid-hybrid and particle simulations. As an application, we show that spectral anomalies of the backscatter, predicted by the above model, are consistent with recent sub-picosecond, high-intensity laser gas-target measurements at Livermore and elsewhere. Finally, a recently proposed scheme for generation of ultra-short, low-prepulse laser pulses by Raman backscattering in a thin foil target, is shown. (author)

  14. Stochastic conditional intensity processes

    DEFF Research Database (Denmark)

    Bauwens, Luc; Hautsch, Nikolaus

    2006-01-01

    model allows for a wide range of (cross-)autocorrelation structures in multivariate point processes. The model is estimated by simulated maximum likelihood (SML) using the efficient importance sampling (EIS) technique. By modeling price intensities based on NYSE trading, we provide significant evidence...

  15. Generation of magnetic fields by the ponderomotive force of electromagnetic waves in dense plasmas

    OpenAIRE

    Shukla, P K; Shukla, Nitin; Stenflo, Lennart

    2010-01-01

    We show that the non-stationary ponderomotive force of a, large-amplitude electromagnetic move in a very dense quantum plasma wall streaming degenerate electrons can spontaneously create d.c. magnetic fields. The present result can account for the seed magnetic fields in compact astrophysical objects and in the next-generation intense laser-solid density, plasma interaction experiments.

  16. What is Data-Intensive Science?

    Energy Technology Data Exchange (ETDEWEB)

    Critchlow, Terence J.; Kleese van Dam, Kerstin

    2013-06-03

    What is Data Intensive Science? Today we are living in a digital world, where scientists often no longer interact directly with the physical object of their research, but do so via digitally captured, reduced, calibrated, analyzed, synthesized and, at times, visualized data. Advances in experimental and computational technologies have lead to an exponential growth in the volumes, variety and complexity of this data and while the deluge is not happening everywhere in an absolute sense, it is in a relative one. Science today is data intensive. Data intensive science has the potential to transform not only how we do science, but how quickly we can translate scientific progress into complete solutions, policies, decisions and ultimately economic success. Critically, data intensive science touches some of the most important challenges we are facing. Consider a few of the grand challenges outlined by the U.S. National Academy of Engineering: make solar energy economical, provide energy from fusion, develop carbon sequestration methods, advance health informatics, engineer better medicines, secure cyberspace, and engineer the tools of scientific discovery. Arguably, meeting any of these challenges requires the collaborative effort of trans-disciplinary teams, but also significant contributions from enabling data intensive technologies. Indeed for many of them, advances in data intensive research will be the single most important factor in developing successful and timely solutions. Simple extrapolations of how we currently interact with and utilize data and knowledge are not sufficient to meet this need. Given the importance of these challenges, a new, bold vision for the role of data in science, and indeed how research will be conducted in a data intensive environment is evolving.

  17. Interactions of light intensity, insecticide concentration, and time on the efficacy of systemic insecticides in suppressing populations of the sweetpotato whitefly (Hemiptera: Aleyrodidae) and the citrus mealybug (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Cloyd, Raymond A; Williams, Kimberly A; Byrne, Frank J; Kemp, Kenneth E

    2012-04-01

    The impact of light intensity on the uptake and persistence of the systemic neonicotinoid insecticides, imidacloprid and dinotefuran, were evaluated in poinsettia (Euphorbia pulcherrima Willd.) and yellow sage (Lantana camara L.). Insecticide residues were measured in leaves sampled from the treated plants at four time intervals after treatment to determine the relationship between insecticide concentration and efficacy against two insect pests: sweetpotato whitefly, Bemisia tabaci Gennadius, and the citrus mealybug, Planococcus citri Risso. The insecticides were evaluated at their respective label rate and at the comparable label rate of the other insecticide under two different light environments: ambient and shade. The uptake of dinotefuran into yellow sage was more rapid at both treatment rates than both rates of imidacloprid, resulting in higher percent mortality of whitefly nymphs (89.8-100) compared with imidacloprid (14.1-89.2) across all 4 wk. Additionally, plants that received both rates of dinotefuran had fewer whitefly pupae (whitefly nymphs (89.5-99.6) compared with imidacloprid (14.1-89.2) across all 4 wk. However, despite efficient uptake, the efficacy of both systemic insecticides was less for citrus mealybug where percent mortality values were <50% among all the treatments across the 4 wk. The use of the two systemic insecticides evaluated in regards to pest management in horticultural cropping systems is discussed.

  18. Intensive culture”

    DEFF Research Database (Denmark)

    Michelsen, Anders Ib

    2012-01-01

    Scott Lash argumenterer i bogen Intensive Culture for en vending fra ”ekstensiv” til ”intensiv” i den nutidige globalisering. Bogens udgangspunkt er en stadig mere ekstensiv og gennemtrængende globalisering af kultur, forbrugs- og vareformer, ”comtemporary culture, today’s capitalism – our global...... information society – is ever more extensive”. Dette medfører imidlertid et paradoks, fordi den ekstensive kultur slår om i intensive kulturformer: ”Given this growing extensification of contemporary culture, on another level and at the same time, we seem to be experiencing a parallel phenomenon whose colours......, samlivsmøstre etc.; ”the sheer pace of life in the streets of today’s mega-city would seem somehow to be intensive”....

  19. Intensities of Mobility

    DEFF Research Database (Denmark)

    Bissell, David; Vannini, Phillip; Jensen, Ole B.

    2016-01-01

    This paper explores the intensities of long-distance commuting journeys in order to understand how bodily sensibilities become attuned to the regular mobilities which they undertake. More people are travelling farther to and from work than ever before, owing to a variety of factors which relate...... to complex social and geographical dynamics of transport, housing, lifestyle, and employment. Yet, the experiential dimensions of long-distance commuting have not received the attention that they deserve within research on mobilities. Drawing from fieldwork conducted in Australia, Canada, and Denmark...... this paper aims to further develop our collective understanding of the experiential particulars of long-distance workers or ‘supercommuters’. Rather than focusing on the extensive dimensions of mobilities that are implicated in broad social patterns and trends, our paper turns to the intensive dimensions...

  20. The future of intensive care medicine.

    Science.gov (United States)

    Blanch, L; Annane, D; Antonelli, M; Chiche, J D; Cuñat, J; Girard, T D; Jiménez, E J; Quintel, M; Ugarte, S; Mancebo, J

    2013-03-01

    Intensive care medical training, whether as a primary specialty or as secondary add-on training, should include key competences to ensure a uniform standard of care, and the number of intensive care physicians needs to increase to keep pace with the growing and anticipated need. The organisation of intensive care in multiple specialty or central units is heterogeneous and evolving, but appropriate early treatment and access to a trained intensivist should be assured at all times, and intensivists should play a pivotal role in ensuring communication and high-quality care across hospital departments. Structures now exist to support clinical research in intensive care medicine, which should become part of routine patient management. However, more translational research is urgently needed to identify areas that show clinical promise and to apply research principles to the real-life clinical setting. Likewise, electronic networks can be used to share expertise and support research. Individuals, physicians and policy makers need to allow for individual choices and priorities in the management of critically ill patients while remaining within the limits of economic reality. Professional scientific societies play a pivotal role in supporting the establishment of a defined minimum level of intensive health care and in ensuring standardised levels of training and patient care by promoting interaction between physicians and policy makers. The perception of intensive care medicine among the general public could be improved by concerted efforts to increase awareness of the services provided and of the successes achieved.

  1. Clinical usefulness of wave intensity analysis.

    Science.gov (United States)

    Sugawara, Motoaki; Niki, Kiyomi; Ohte, Nobuyuki; Okada, Takashi; Harada, Akimitsu

    2009-02-01

    Wave intensity (WI) is a hemodynamic index, which can evaluate the working condition of the heart interacting with the arterial system. It can be defined at any site in the circulatory system and provides a great deal of information. However, we need simultaneous measurements of blood pressure and velocity to obtain wave intensity, which has limited the clinical application of wave intensity, in spite of its potential. To expand the application of wave intensity in the clinical setting, we developed a real-time non-invasive measurement system for wave intensity based on a combined color Doppler and echo-tracking system. We measured carotid arterial WI in normal subjects and patients with various cardiovascular diseases. In the coronary artery disease group, the magnitude of the first peak of carotid arterial WI (W (1)) increased with LV max. dP/dt (r = 0.74, P WI can be obtained non-invasively using an echo-Doppler system in the clinical setting. This method will increase the clinical usefulness of wave intensity.

  2. Intense fusion neutron sources

    Science.gov (United States)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  3. Intensidad exportadora e interacción entre fortalezas del marketing mix: un análisis basado en redes neuronales artificiales || Export Intensity and Interaction between Marketing Mix: An Analysis based on Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Gutiérrez-Villar, Belén

    2014-12-01

    Full Text Available Entre los factores determinantes de la actuación exportadora de las empresas, numerosos estudios han subrayado la relevancia del mix de marketing. Generalmente, la mayoría de los estudios abordan el análisis de las variables centrado en estrategias específicas, en particular fenómenos de estandarización-adaptación. El presente estudio analiza si existe un efecto interactivo de fortalezas generadas en las diferentes variables del mix de marketing que pueda asociarse a diferentes perfiles exportadores. Para ello, se ha empleado el algoritmo Extreme Learning Machine (ELM dentro de los procedimientos Perceptrón Multicapa (MLP de Redes Neuronales Artificiales (RNA. Asimismo, el análisis se combina con un novedoso procedimiento de análisis de sensibilidad desarrollado ad hoc para este estudio, el cual permite conocer los efectos individuales e interactivos de las variables predictoras sobre la variable dependiente en problemas clasificatorios de naturaleza dicotómica. Los resultados obtenidos nos permiten corroborar la existencia de los efectos interactivos postulados, poniendo al mismo tiempo de manifiesto la utilidad de las RNA y del análisis de sensibilidad propuesto para la investigación en el área de marketing y, específicamente, para los estudios de internacionalización de empresas. || Among the determining factors in export activity, many studies have highlighted the relevance of the marketing mix. Generally, the majority of them use a variables analysis to focus on specific strategies, in particular, standardized-adaptations. This paper analyzes if there is an interactive effect of strength generated in different variables of the marketing mix that can be associated with different export profiles. The Extreme Learning Machine (ELM algorithm has been used within the Multilayer Perceptron (MLP of Artificial Neural Networks (ANN. In addition, the analyses combine a novel approach for sensitivity analysis developed ad hoc for this

  4. The Stress Intensity Factor Variation of Two Cracks Interaction in Nuclear Piping%两裂纹在核管道中应力强度因子的相互影响研究

    Institute of Scientific and Technical Information of China (English)

    白鑫; 谢里阳

    2015-01-01

    With the aging of nuclear power plants,safety assessment for nuclear pipeline becomes more important.In the past,the assessment of nuclear piping only consider a single crack problem;or confined to the issue of a main crack;or focused on considering two cracks meeting any condition to be merged into one crack,namely,detailed study on multiple cracks under the stress intensity factor variation is rough.It is not a perfect part of fracture mechanics for multiple crack problems.In order to improve the content of fracture mechanics,fracture mechanics applied to increase the value and improve the safety and reliability of nuclear piping,inner surface cracks is determined as the major flaws of nuclear piping,the role of nuclear piping two cracks stress intensity factor and its general form are obtained by analysis of the actual variation with the finite element method.Two crack phenomenon is the basic situation of multiple cracks.Thus,this work provides a method to assess the basis for the existence of multiple cracks in nuclear safety pipeline.%随着核电站的老化,核管道安全评估变得更为重要。以往核管道的损伤容限评定通常只考虑单一裂纹问题,或只局限于研究一个主裂纹的问题,或主要集中于考虑两个裂纹满足何条件时,二者方可合并为一个裂纹的问题,对多裂纹情况下应力强度因子变化规律的研究较粗糙。在理论与方法方面,多裂纹问题一直是断裂力学不够完善的部分。本文以核管道的内表面裂纹为对象,采用有限元法分析核管道两个裂纹情况下的应力强度因子,得到其随裂纹间距、裂纹长度、裂纹深度变化的规律。又两个裂纹的现象为多裂纹现象中最基本的情况,即本研究工作可为存在多裂纹的核管道的安全评估提供方法依据。

  5. Global relationship of fire occurrence and fire intensity: A test of intermediate fire occurrence-intensity hypothesis

    Science.gov (United States)

    Luo, Ruisen; Hui, Dafeng; Miao, Ning; Liang, Chuan; Wells, Nicholas

    2017-05-01

    Fire plays a significant role in global atmosphere and biosphere carbon and nutrient cycles. Globally, there are substantially different distributions and impacts between fire occurrence and fire intensity. It is prominent to have a thorough investigation of global relationship between fire occurrence and fire intensity for future fire prediction and management. In this study, we proposed an intermediate fire occurrence-intensity (IFOI) hypothesis for the global relationship between fire occurrence and fire intensity, suggesting that fire occurrence changes with fire intensity following a humped relationship. We examined this hypothesis via satellite data from January 2001 to December 2013 at a global scale, and in small and large fire intensity zones, respectively. Furthermore, the fire occurrence and fire intensity relationship was developed among different vegetation types to reveal the changes of parameters and strengths. Finally, the environmental factors (including climatic, hydraulic, biological, and anthropogenic variables) underpinning the fire occurrence and intensity pattern were evaluated for the underlying mechanisms. The results supported our IFOI hypothesis and demonstrated that the humped relationship is driven by different causes among vegetation types. Fire occurrence increases with fire intensity in small fire intensity zones due to alleviation of the factors limiting both fire occurrence and intensity. Beyond a certain fire intensity threshold, fire occurrence is constrained, probably due to the limitation of available fuels. The information generated in this study could be helpful for understanding global variation of fire occurrence and fire intensity due to fire-vegetation-climate-human interactions and facilitating future fire management.

  6. Relativistic motion of charged particles in the interaction of short pulses of intense laser light with plasma; Movimiento relativista de particulas cargadas en la interaccion de pulsos cortos de luz laser intensa con plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gomez R, F

    2004-07-01

    In the chapter 1 we show the foundations of the special relativity in the frame of the classical mechanics and we develop the necessary theory for the theoretical description of the relativistic dynamics of charged particles in the interaction with electromagnetic fields. It will see that starting from the energy conservation principle is derived the Einstein's law that establishes the relationship among this and the mass. Later on, it will take the action of a charged particle in a given radiation field and in the one which only we will take two parts, the action of the free particle and the one that defines the interaction of this with the field. The equations of motion of a charge in an electromagnetic field come given by the Lagrange equations, being obtained an expression for the force, well-known as Lorentz force, which consists of two terms, the first of them is the force that the electric field E exercises on the particle; which doesn't depend on the charge speed and is oriented in the direction of the field, the second term represents the force that exercises the magnetic field B and that it is proportional to the charge speed, being perpendicular to the direction of it. In the chapter 2 an integration method of the Hamilton-Jacobi for the case of a pulse is that allows to found analytical forms for the moment, the energy and the charge position is developed with detail. We will present, also, a discussion of the classical theory of the relativistic dynamic of free electrons. They are also obtained, invariant quantities like the phase, before the frame of the reference inertial changes, well-known as Lorentz invariants of the system. In this part it is considered to the electron in the laboratory frame (frame in which the particle is initially in repose regarding the observer), of which the speed and the acceleration quadrivectors can be calculated. We demonstrate that the {eta} phase is a Lorentz invariant. It is shown, also that the proper time

  7. Identification of clinically significant drug-drug interactions in cardiac ...

    African Journals Online (AJOL)

    Purpose: To identify clinically significant potential drug-drug interactions in cardiac intensive care units of two tertiary care ... Keywords: Pharmacy service, Drug interactions, Critical/intensive care, Adverse outcomes. Tropical .... Standard error.

  8. Progress in ultrafast intense laser science XII

    CERN Document Server

    Roso, Luis; Li, Ruxin; Mathur, Deepak; Normand, Didier

    2015-01-01

    This  volume covers a broad range of topics focusing on atoms, molecules, and clusters interacting in intense laser field, laser induced filamentation, and laser plasma interaction and application. The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries. .

  9. Protecting coherence by reservoir engineering: intense bath disturbance

    Science.gov (United States)

    Zhou, Zixian; Lü, Zhiguo; Zheng, Hang

    2016-08-01

    We put forward a scheme based on reservoir engineering to protect quantum coherence from leaking to bath, in which we intensely disturb the Lorentzian bath by N harmonic oscillators. We show that the intense disturbance changes the spectrum of the bath and reduces the qubit-bath interaction. Furthermore, we give the exact time evolution with the Lorentzian spectrum by a master equation and calculate the concurrence and survival probability of the qubits to demonstrate the effect of the intense bath disturbance on the protection of coherence. Meanwhile, we reveal the dynamic effects of counter-rotating interaction on the qubits as compared to the results of the rotating-wave approximation.

  10. Lectures on Ultrafast Intense Laser Science 1 Volume 1

    CERN Document Server

    Yamanouchi, Kaoru

    2011-01-01

    This book features tutorial-like chapters on ultrafast intense laser science by world-leading scientists who are active in the rapidly developing interdisciplinary research field. It is written to give a comprehensive survey of all the essential aspects of ultrafast intense laser science. The volume covers theories of atoms and molecules in intense laser fields, high intensity physics scaled to long wavelength, pulse shaping techniques, non-linear optics in the XUV region, ultrafast X-ray spectroscopy, quantum emission and applications, filamentation, and ultraintense-laser matter interaction.

  11. Focusing of Intense Laser via Parabolic Plasma Concave Surface

    Science.gov (United States)

    Zhou, Weimin; Gu, Yuqiu; Wu, Fengjuan; Zhang, Zhimeng; Shan, Lianqiang; Cao, Leifeng; Zhang, Baohan

    2015-12-01

    Since laser intensity plays an important role in laser plasma interactions, a method of increasing laser intensity - focusing of an intense laser via a parabolic plasma concave surface - is proposed and investigated by three-dimensional particle-in-cell simulations. The geometric focusing via a parabolic concave surface and the temporal compression of high harmonics increased the peak intensity of the laser pulse by about two orders of magnitude. Compared with the improvement via laser optics approaches, this scheme is much more economic and appropriate for most femtosecond laser facilities. supported by National Natural Science Foundation of China (Nos. 11174259, 11175165), and the Dual Hundred Foundation of China Academy of Engineering Physics

  12. A conceptual framework of clinical nursing care in intensive care

    Directory of Open Access Journals (Sweden)

    Rafael Celestino da Silva

    2015-10-01

    Full Text Available Objective: to propose a conceptual framework for clinical nursing care in intensive care.Method: descriptive and qualitative field research, carried out with 21 nurses from an intensive care unit of a federal public hospital. We conducted semi-structured interviews and thematic and lexical content analysis, supported by Alceste software.Results: the characteristics of clinical intensive care emerge from the specialized knowledge of the interaction, the work context, types of patients and nurses characteristic of the intensive care and care frameworks.Conclusion: the conceptual framework of the clinic's intensive care articulates elements characteristic of the dynamics of this scenario: objective elements regarding technology and attention to equipment and subjective elements related to human interaction, specific of nursing care, countering criticism based on dehumanization.

  13. A conceptual framework of clinical nursing care in intensive care.

    Science.gov (United States)

    da Silva, Rafael Celestino; Ferreira, Márcia de Assunção; Apostolidis, Thémistoklis; Brandão, Marcos Antônio Gomes

    2015-01-01

    to propose a conceptual framework for clinical nursing care in intensive care. descriptive and qualitative field research, carried out with 21 nurses from an intensive care unit of a federal public hospital. We conducted semi-structured interviews and thematic and lexical content analysis, supported by Alceste software. the characteristics of clinical intensive care emerge from the specialized knowledge of the interaction, the work context, types of patients and nurses characteristic of the intensive care and care frameworks. the conceptual framework of the clinic's intensive care articulates elements characteristic of the dynamics of this scenario: objective elements regarding technology and attention to equipment and subjective elements related to human interaction, specific of nursing care, countering criticism based on dehumanization.

  14. 21 cm Intensity Mapping

    CERN Document Server

    Peterson, Jeffrey B; Ansari, Reza; Bandura, Kevin; Bond, Dick; Bunton, John; Carlson, Kermit; Chang, Tzu-Ching; DeJongh, Fritz; Dobbs, Matt; Dodelson, Scott; Darhmaoui, Hassane; Gnedin, Nick; Halpern, Mark; Hogan, Craig; Goff, Jean-Marc Le; Liu, Tiehui Ted; Legrouri, Ahmed; Loeb, Avi; Loudiyi, Khalid; Magneville, Christophe; Marriner, John; McGinnis, David P; McWilliams, Bruce; Moniez, Marc; Palanque-Delabruille, Nathalie; Pasquinelli, Ralph J; Pen, Ue-Li; Rich, Jim; Scarpine, Vic; Seo, Hee-Jong; Sigurdson, Kris; Seljak, Uros; Stebbins, Albert; Steffen, Jason H; Stoughton, Chris; Timbie, Peter T; Vallinotto, Alberto; Wyithe, Stuart; Yeche, Christophe

    2009-01-01

    Using the 21 cm line, observed all-sky and across the redshift range from 0 to 5, the large scale structure of the Universe can be mapped in three dimensions. This can be accomplished by studying specific intensity with resolution ~ 10 Mpc, rather than via the usual galaxy redshift survey. The data set can be analyzed to determine Baryon Acoustic Oscillation wavelengths, in order to address the question: 'What is the nature of Dark Energy?' In addition, the study of Large Scale Structure across this range addresses the questions: 'How does Gravity effect very large objects?' and 'What is the composition our Universe?' The same data set can be used to search for and catalog time variable and transient radio sources.

  15. Cosmic Dawn Intensity Mapper

    CERN Document Server

    Cooray, Asantha; Burgarella, Denis; Chary, Ranga; Chang, Tzu-Ching; Doré, Olivier; Fazio, Giovanni; Ferrara, Andrea; Gong, Yan; Santos, Mario; Silva, Marta; Zemcov, Michael

    2016-01-01

    Cosmic Dawn Intensity Mapper is a "Probe Class" mission concept for reionization studies of the universe. It will be capable of spectroscopic imaging observations between 0.7 to 6-7 microns in the near-Infrared. The primary observational objective is pioneering observations of spectral emission lines of interest throughout the cosmic history, but especially from the first generation of distant, faint galaxies when the universe was less than 800 million years old. With spectro-imaging capabilities, using a set of linear variable filters (LVFs), CDIM will produce a three-dimensional tomographic view of the epoch of reionization (EoR). CDIM will also study galaxy formation over more than 90% of the cosmic history and will move the astronomical community from broad-band astronomical imaging to low-resolution (R=200-300) spectro-imaging of the universe.

  16. The Danish Intensive Care Database

    DEFF Research Database (Denmark)

    Christiansen, Christian Fynbo; Møller, Morten Hylander; Nielsen, Henrik

    2016-01-01

    AIM OF DATABASE: The aim of this database is to improve the quality of care in Danish intensive care units (ICUs) by monitoring key domains of intensive care and to compare these with predefined standards. STUDY POPULATION: The Danish Intensive Care Database (DID) was established in 2007...

  17. The Taxonomy of Intervention Intensity

    Science.gov (United States)

    Fuchs, Lynn S.; Fuchs, Douglas; Malone, Amelia S.

    2016-01-01

    The purpose of this article is to describe the Taxonomy of Intervention Intensity, which articulates 7 dimensions for evaluating and building intervention intensity. We explain the Taxonomy's dimensions of intensity. In explaining the Taxonomy, we rely on a case study to illustrate how the Taxonomy can systematize the process by which special…

  18. Self-trapping of intensities changing under SHG and SWG for high intensive femtosecond laser pulse

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Kharitonov, Dmitry M.; Fedotov, Mikhail V.

    2017-05-01

    SHG and SFG (SWG) and THG are used widely in many practical applications such as a substance diagnostics, and imaging of various physical, chemical and biological processes as well as for laser radiation frequency conversion. One of very interesting phenomena under the frequency conversion takes place if a basic wave incident intensity is enough high: a synchronic mode of the laser pulse intensities changing along a propagation coordinate appears under certain conditions. First of all, we investigate this phenomenon using the frame-work of long pulse duration approximation and plane wave approximation without applying the basic wave energy non-depletion approximation. Applying an original approach we derive the solution of Schr¨odinger equations describing the THG via a SHG process and summary frequency wave generation (SFG) process for femtosecond pulses. Among many modes of the frequency conversion process under consideration we found out analytically the mode corresponding to synchronous intensities changing for the interacting waves. We derive conditions of such mode realization in dependence of the problem parameters. After that we verify our analytical consideration using a computer simulation of the problem on the base of the corresponding Schr¨odinger equations. Computer simulation shown also a new phenomenon at three-wave interaction: interacting wave intensities changing with two (or more) oscillation periods.

  19. An Ocean-Based Potential Intensity Index for Tropical Cyclones

    Science.gov (United States)

    Lin, I. I.; Black, P. G.; Price, J. F.; Yang, C.; Chen, S. S.; Chi, N.; Harr, P.; Lien, C.; D'Asaro, E. A.; Wu, C.

    2012-12-01

    Improvement in tropical cyclones' intensity prediction is an important ongoing effort. Cooling of the ocean by storm mixing reduces storm intensity by reducing the air-sea enthalpy flux. Here, we modify the widely used Sea Surface Temperature Potential Intensity (SST_PI) index by including information from the upper subsurface ocean to form a new Ocean Cooling Potential Intensity index, OC_PI. Applied to a 14-year (1998-2011) Western Pacific typhoon archive, the correlation coefficient between the predicted maximum intensity and the observed peak intensity increased from 0.08 to 0.31. For the sub group of slow-moving TCs that has the strongest interaction with subsurface ocean, r2 increases to 0.56. OC_PI thus contributes to the improvement on the existing PI through incorporation of ocean's subsurface information.

  20. Beam-Material Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, N. V. [Fermilab; Cerutti, F. [CERN

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high-intensity energetic particle beam interactions with accelerator, generic target, and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and environment in challenging current and future applications.

  1. Beam-Material Interaction

    CERN Document Server

    Mokhov, N.V.

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high- intensity energetic particle beam interactions with accelerator, generic target , and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and envir onment in challenging current and future application

  2. Whistler intensities above thunderstorms

    Directory of Open Access Journals (Sweden)

    J. Fiser

    2010-01-01

    Full Text Available We report a study of penetration of the VLF electromagnetic waves induced by lightning to the ionosphere. We compare the fractional hop whistlers recorded by the ICE experiment onboard the DEMETER satellite with lightning detected by the EUCLID detection network. To identify the fractional hop whistlers, we have developed software for automatic detection of the fractional-hop whistlers in the VLF spectrograms. This software provides the detection times of the fractional hop whistlers and the average amplitudes of these whistlers. Matching the lightning and whistler data, we find the pairs of causative lightning and corresponding whistler. Processing data from ~200 DEMETER passes over the European region we obtain a map of mean amplitudes of whistler electric field as a function of latitudinal and longitudinal difference between the location of the causative lightning and satellite magnetic footprint. We find that mean whistler amplitude monotonically decreases with horizontal distance up to ~1000 km from the lightning source. At larger distances, the mean whistler amplitude usually merges into the background noise and the whistlers become undetectable. The maximum of whistler intensities is shifted from the satellite magnetic footprint ~1° owing to the oblique propagation. The average amplitude of whistlers increases with the lightning current. At nighttime (late evening, the average amplitude of whistlers is about three times higher than during the daytime (late morning for the same lightning current.

  3. Emotionally Intense Science Activities

    Science.gov (United States)

    King, Donna; Ritchie, Stephen; Sandhu, Maryam; Henderson, Senka

    2015-08-01

    Science activities that evoke positive emotional responses make a difference to students' emotional experience of science. In this study, we explored 8th Grade students' discrete emotions expressed during science activities in a unit on Energy. Multiple data sources including classroom videos, interviews and emotion diaries completed at the end of each lesson were analysed to identify individual student's emotions. Results from two representative students are presented as case studies. Using a theoretical perspective drawn from theories of emotions founded in sociology, two assertions emerged. First, during the demonstration activity, students experienced the emotions of wonder and surprise; second, during a laboratory activity, students experienced the intense positive emotions of happiness/joy. Characteristics of these activities that contributed to students' positive experiences are highlighted. The study found that choosing activities that evoked strong positive emotional experiences, focused students' attention on the phenomenon they were learning, and the activities were recalled positively. Furthermore, such positive experiences may contribute to students' interest and engagement in science and longer term memorability. Finally, implications for science teachers and pre-service teacher education are suggested.

  4. 强激光与锥型结构靶相互作用准直电子束粒子模拟研究%Collimated electrons generated by intense laser pulse interaction with cone-structured targets using particle simulation

    Institute of Scientific and Technical Information of China (English)

    吴凤娟; 王为武; 张锋; 谷渝秋; 张保汉; 周维民; 单连强; 李芳; 刘东晓; 张智猛; 李博原; 毕碧; 伍波

    2014-01-01

    Generation and propagation of fast electron bunches from interaction of short, ultra intense laser with cone-sandwich target are investigated by PIC (particle-in-cell) simulation. Results are compared with those in the interaction of the same laser parameters with cone-channel target, cone-wire target and cone target. Fast electrons generated by the interaction of intense laser with cone-sandwich target can be effectively collimated and propagated by the quasi-static strong magnetic field generated by the material surface of different densities. Compared with the other three cone-structured target, the more number and the higher energy of the fast electrons are generated by cone-sandwich target. This can well improve the energy conversion efficiency of the laser to fast electrons and the quality of fast electron bunches, which are favorable for the fast ignition energy deposition.%利用PIC(particle-in-cell)方法模拟研究了超短强激光与锥型三明治结构靶相互作用快电子束的产生和传输,并与锥通道靶、锥丝靶和锥靶在相同激光参数下的作用结果进行了比较。研究发现强激光与锥三明治靶作用产生的快电子能被不同密度材料产生的准静态界面强磁场有效地准直传输。相对其他三种锥型结构靶,锥三明治靶能产生更多数目及更高能量的快电子,提高了激光到快电子的能量转换效率和快电子束的品质,这对快点火能量沉积是有利的。

  5. Organizing Safe Transitions from Intensive Care

    Directory of Open Access Journals (Sweden)

    Marie Häggström

    2014-01-01

    Full Text Available Background. Organizing and performing patient transfers in the continuum of care is part of the work of nurses and other staff of a multiprofessional healthcare team. An understanding of discharge practices is needed in order to ultimate patients’ transfers from high technological intensive care units (ICU to general wards. Aim. To describe, as experienced by intensive care and general ward staff, what strategies could be used when organizing patient’s care before, during, and after transfer from intensive care. Method. Interviews of 15 participants were conducted, audio-taped, transcribed verbatim, and analyzed using qualitative content analysis. Results. The results showed that the categories secure, encourage, and collaborate are strategies used in the three phases of the ICU transitional care process. The main category; a safe, interactive rehabilitation process, illustrated how all strategies were characterized by an intention to create and maintain safety during the process. A three-way interaction was described: between staff and patient/families, between team members and involved units, and between patient/family and environment. Discussion/Conclusions. The findings highlight that ICU transitional care implies critical care rehabilitation. Discharge procedures need to be safe and structured and involve collaboration, encouraging support, optimal timing, early mobilization, and a multidiscipline approach.

  6. High-Power, High-Intensity Laser Propagation and Interactions

    Science.gov (United States)

    2014-03-10

    Krushelnick, A.Ting, C.I. Moore, H. R. Burris, E. Esarey, P. Sprangle and M. Baine, Phys. Rev. Lett. 78, 4047 (1997). 71. Y. Ehrlich , C. Cohen, D...R. Burris, Y. Ehrlich , R. Hubbard and P. Sprangle, Phys. Rev. E 59, R4769 (1999). 73. A.B. Borisov, A.V. Borovskiy, O.B. Shiryaev, V.V. Korobkin A

  7. Knowledge-Intensive, Interactive and Efficient Relational Pattern Learning

    Science.gov (United States)

    2006-09-01

    sub- sumption ( Gottlob , 1987), Marcinkowski and Pacholski’s result on the undecidability of implication between definite clauses (Marcinkowski and...satisfaction problems. Journal of Automated Reasoning, 24:67–100, 2000. G. Gottlob . Subsumption and implication. Information Processing Letters, 24(2...Letters, 496:237-241. 16. E. Dantsin, T. Eiter, G. Gottlob & A. Voronkov (2001). Complexity and expressive power of logic programming. ACM Computing

  8. Understanding Intense Laser Interactions with Solid Density Plasma

    Science.gov (United States)

    2017-01-04

    NOTES. Enter information not included elsewhere such as: prepared in cooperation with; translation of; report supersedes; old edition number, etc...3Scientific RepoRts | 6:36224 | DOI: 10.1038/srep36224 To demonstrate that this set-up is not limited by the electron source but the magnetic -deflection...are pre- sented in Fig. 4 for ultrafast dynamics of the undiffracted (0-order) and one of the (220)-order peaks. The pump solenoid magnetic lens LPA

  9. Progress in Ultrafast Intense Laser Science VIII

    CERN Document Server

    Nisoli, Mauro; Hill, Wendell; III, III

    2012-01-01

    The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science and optical science which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield as well as graduate students can grasp the importance and attractions of the research topic at hand. These are followed by reports of cutting-edge discoveries. This eighth volume covers a broad range of topics from this interdisciplinary research field, focusing on molecules interacting with ultrashort and intense laser fields, advanced technologies for the characterization of ultrashort laser pulses and their applications, laser plasma formation and laser acceleration.

  10. Intense, ultrashort light and dense, hot matter

    Indian Academy of Sciences (India)

    G Ravindra Kumar

    2009-07-01

    This article presents an overview of the physics and applications of the interaction of high intensity laser light with matter. It traces the crucial advances that have occurred over the past few decades in laser technology and nonlinear optics and then discusses physical phenomena that occur in intense laser fields and their modeling. After a description of the basic phenomena like multiphoton and tunneling ionization, the physics of plasma formed in dense matter is presented. Specific phenomena are chosen for illustration of the scientific and technological possibilities – simulation of astrophysical phenomena, relativistic nonlinear optics, laser wakefield acceleration, laser fusion, ultrafast real time X-ray diffraction, application of the particle beams produced from the plasma for medical therapies etc. A survey of the Indian activities in this research area appears at the end.

  11. Progress in Ultrafast Intense Laser Science III

    CERN Document Server

    Yamanouchi, Kaoru; Agostini, Pierre; Ferrante, Gaetano

    2008-01-01

    The PUILS series presents Progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science. PUILS has been stimulated by the recent development of ultrafast laser technologies. Each volume contains approximately 15 chapters, authored by researchers at the forefront. Each chapter opens with an overview of the topics to be discussed, so that researchers, who are not experts in the specific topics, as well as graduate students can grasp the importance and attractions of this sub-field of research, and these are followed by reports of cutting-edge discoveries. This third volume covers a diverse range of disciplines, focusing on such topics as strong field ionization of atoms, ionization and fragmentation of molecules and clusters, generation of high-order harmonics and attosecond pulses, filamentation and laser plasma interaction, and the development of ultrashort and ultrahigh-intensity light sources.

  12. Progress in Ultrafast Intense Laser Science VI

    CERN Document Server

    Yamanouchi, Kaoru; Bandrauk, André D

    2010-01-01

    The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries. This sixth volume covers a broad range of topics from this interdisciplinary research field, focusing on responses of molecules to ultrashort intense laser pulses, generation and characterization of attosecond pulses and high-order harmonics, and filamentation and laser-plasma interaction.

  13. The language of pain: intensity.

    Science.gov (United States)

    Bailey, C A; Davidson, P O

    1976-09-01

    Thirty-nine adjectives which may be used to describe a pain experience were rated on an "intensity" continuum by 93 subjects, and in a second study by an additional 90 subjects. In each study these ratings were intercorrelated and factor-analyzed. The first 6 factors extracted were rotated to a simple structure criterion. The first factor was identified as an "intensity" factor. Examination of the adjectives indicated that intensity relates to "affective-evaluative" adjectives rather than "sensory" ones. The implications of these findings for the language a patient may use to communicate the intensity of a pain are discussed.

  14. Handbook of data intensive computing

    CERN Document Server

    Furht, Borko

    2011-01-01

    Data Intensive Computing refers to capturing, managing, analyzing, and understanding data at volumes and rates that push the frontiers of current technologies. The challenge of data intensive computing is to provide the hardware architectures and related software systems and techniques which are capable of transforming ultra-large data into valuable knowledge. Handbook of Data Intensive Computing is written by leading international experts in the field. Experts from academia, research laboratories and private industry address both theory and application. Data intensive computing demands a fund

  15. Aligning molecules with intense nonresonant laser fields

    DEFF Research Database (Denmark)

    Larsen, J.J.; Safvan, C.P.; Sakai, H.

    1999-01-01

    Molecules in a seeded supersonic beam are aligned by the interaction between an intense nonresonant linearly polarized laser field and the molecular polarizability. We demonstrate the general applicability of the scheme by aligning I2, ICl, CS2, CH3I, and C6H5I molecules. The alignment is probed...... by mass selective two dimensional imaging of the photofragment ions produced by femtosecond laser pulses. Calculations on the degree of alignment of I2 are in good agreement with the experiments. We discuss some future applications of laser aligned molecules....

  16. Particle Physics in Intense Electromagnetic Fields

    CERN Document Server

    Kurilin, A V

    1999-01-01

    The quantum field theory in the presence of classical background electromagnetic fields is reviewed. We give a pedagogical introduction to the Feynman-Furry method of describing non-perturbative interactions with very strong electromagnetic fields. A particular emphasis is given to the case of the plane-wave electromagnetic field for which the charged particles' wave functions and propagators are presented. Some general features of quantum processes proceeding in the intense electromagnetic background are argued. We also discuss the possibilities of searching new physics through the investigations of quantum phenomena induced by the strong electromagnetic environment.

  17. Catfish production using intensive aeration

    Science.gov (United States)

    For the last 3 years, researchers at UAPB and NWAC have been monitoring and verifying production yields in intensively aerated catfish ponds with aeration rates greater than 6 hp/acre. We now have three years of data on commercial catfish production in intensively aerated ponds. With stocking densi...

  18. The Dynamics of Intensive Cultivation

    OpenAIRE

    Christian Bidard

    2008-01-01

    An increase in the demand for agricultural goods leads to the use of more intensive cultivation methods. Though Ricardo sees no difficulties in the intensification process, their existence is revealed by the possible occurrence of multiple equilibria. A general theory of intensive rent is based on a formal parallel with single-product systems without land.

  19. Traffic light intensity meter, TIM®

    NARCIS (Netherlands)

    Leden, N. van der; Varkevisser, J.; Vroom, J. de; Oijen, T van

    2005-01-01

    The intensity of traffic lights decreases over time as a result of pollution and ageing. The Dutch Traffic Research Centre of the Ministry of Transport, Public Works and Water Management is searching for a convenient method for measuring the luminous intensity of traffic lights on the road, in order

  20. MRI intensity inhomogeneity correction by combining intensity and spatial information

    Energy Technology Data Exchange (ETDEWEB)

    Vovk, Uros; Pernus, Franjo; Likar, Bostjan [Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, 1000 Ljubljana (Slovenia)

    2004-09-07

    We propose a novel fully automated method for retrospective correction of intensity inhomogeneity, which is an undesired phenomenon in many automatic image analysis tasks, especially if quantitative analysis is the final goal. Besides most commonly used intensity features, additional spatial image features are incorporated to improve inhomogeneity correction and to make it more dynamic, so that local intensity variations can be corrected more efficiently. The proposed method is a four-step iterative procedure in which a non-parametric inhomogeneity correction is conducted. First, the probability distribution of image intensities and corresponding second derivatives is obtained. Second, intensity correction forces, condensing the probability distribution along the intensity feature, are computed for each voxel. Third, the inhomogeneity correction field is estimated by regularization of all voxel forces, and fourth, the corresponding partial inhomogeneity correction is performed. The degree of inhomogeneity correction dynamics is determined by the size of regularization kernel. The method was qualitatively and quantitatively evaluated on simulated and real MR brain images. The obtained results show that the proposed method does not corrupt inhomogeneity-free images and successfully corrects intensity inhomogeneity artefacts even if these are more dynamic.

  1. Intense electron and ion beams

    CERN Document Server

    Molokovsky, Sergey Ivanovich

    2005-01-01

    Intense Ion and Electron Beams treats intense charged-particle beams used in vacuum tubes, particle beam technology and experimental installations such as free electron lasers and accelerators. It addresses, among other things, the physics and basic theory of intense charged-particle beams; computation and design of charged-particle guns and focusing systems; multiple-beam charged-particle systems; and experimental methods for investigating intense particle beams. The coverage is carefully balanced between the physics of intense charged-particle beams and the design of optical systems for their formation and focusing. It can be recommended to all scientists studying or applying vacuum electronics and charged-particle beam technology, including students, engineers and researchers.

  2. The economics of intense exercise.

    Science.gov (United States)

    Meltzer, David O; Jena, Anupam B

    2010-05-01

    Despite the well-known benefits of exercise, the time required for exercise is widely understood as a major reason for low levels of exercise in the US. Intensity of exercise can change the time required for a given amount of total exercise but has never been studied from an economic perspective. We present a simple model of exercise behavior which suggests that the intensity of exercise should increase relative to time spent exercising as wages increase, holding other determinants of exercise constant. Our empirical results identify an association between income and exercise intensity that is consistent with the hypothesis that people respond to increased time costs of exercise by increasing intensity. More generally, our results suggest that time costs may be an important determinant of exercise patterns and that factors that can influence the time costs of exercise, such as intensity, may be important concerns in designing interventions to promote exercise.

  3. High Intensity Particle Physics at PW-class laser facilities

    Science.gov (United States)

    Bulanov, Stepan; Schroeder, Carl; Esarey, Eric; Esirkepov, Timur; Kando, Masaki; Rosanov, Nikolay; Korn, Georg; Bulanov, Sergey V.; Leemans, Wim P.

    2015-11-01

    The processes typical for high intensity particle physics, i.e., the interactions of charged particles with strong electromagnetic fields, have attracted considerable interest recently. Some of these processes, previously believed to be of theoretical interest only, are now becoming experimentally accessible. High intensity electromagnetic (EM) fields significantly modify the interactions of particles and EM fields, giving rise to the phenomena that are not encountered either in classical or perturbative quantum theory of these interactions. One of such phenomena is the radiation reaction, which radically influences the electron motion in an electromagnetic standing wave formed by two super-intense counter-propagating laser pulses. Depending on the laser intensity and wavelength, either classical or quantum mode of radiation reaction prevail, or both are strong. When radiation reaction dominates, electron motion evolves to limit cycles and strange attractors. This creates a new framework for high energy physics experiments on an interaction of energetic charged particle beams and colliding super-intense laser pulses. Work supported by U.S. DOE under Contract No. DE-AC02-05CH11231.

  4. Intensive insulin therapy in the intensive cardiac care unit.

    Science.gov (United States)

    Hasin, Tal; Eldor, Roy; Hammerman, Haim

    2006-01-01

    Treatment in the intensive cardiac care unit (ICCU) enables rigorous control of vital parameters such as heart rate, blood pressure, body temperature, oxygen saturation, serum electrolyte levels, urine output and many others. The importance of controlling the metabolic status of the acute cardiac patient and specifically the level of serum glucose was recently put in focus but is still underscored. This review aims to explain the rationale for providing intensive control of serum glucose levels in the ICCU, especially using intensive insulin therapy and summarizes the available clinical evidence suggesting its effectiveness.

  5. Potential drug interactions in intensive care patients at a teaching hospital Interacciones medicamentosas potenciales en pacientes de una unidad de terapia intensiva de un hospital universitario Interações medicamentosas potenciais em pacientes de unidade de terapia intensiva de um hospital universitário

    Directory of Open Access Journals (Sweden)

    Rhanna Emanuela Fontenele Lima

    2009-04-01

    Full Text Available This study assessed potential drugs interactions in intensive care patients at a university hospital in Ceará, northeast Brazil. Of 102 patients studied, 72.5% were exposed to 311 potential drug-drug interactions; 64% of them were females aged 60 years or more and hospital stay was at least 9 days. A statistically significant association was found between number of drugs used and the occurrence of drug interactions. A total of 1,140 drugs were scheduled to be administered concomitantly; of these, 74% had potential for drug interactions. As for the classification of these events, 48.2% had a pharmacokinetic profile; 55.4% were of slow onset; 54.7% had moderate severity; and 60.6% were well-documented in the literature. The most common clinical action taken was "to monitor signs and symptoms". Nursing staff can perform 80% of preventive actions to avoid undesirable effects of drug interactions. However, nurses need to have adequate knowledge about drug action mechanisms and triggering factors associated to drug interactions.Este estudio investigó interacciones medicamentosas (IM potenciales en una Unidad de Terapia Intensiva (UTI en un hospital universitario del Ceará. De los 102 pacientes del estudio, 72,5% presentaron 311 potenciales IMs. De estos, 64% eran del sexo femenino, con edad mayor o igual a 60 años y tiempo de internación mayor o igual a nueve días. Hubo una asociación estadísticamente significativa entre el número de medicamentos y la ocurrencia de IM; 1.140 medicamentos fueron administrados durante el mismo horario, entre estos, 74% presentaron potencial para IM. En lo que se refiere a la clasificación de las IMs, 48,2% presentaron un perfil fármaco cinético, 55,4% inicio demorado, 54,7% moderada gravedad y 60,6% bien documentadas en la literatura. El manejo clínico más frecuente fue "observar señales y síntomas". Ochenta por ciento de las intervenciones para evitar los efectos indeseables de las IMs pueden ser

  6. Theoretical calculation on CIDEP intensity of radical-triplet pairs based on the full interaction Hamiltonian%自由基-三重态对化学诱导动态电子极化强度的全哈密顿计算

    Institute of Scientific and Technical Information of China (English)

    许新胜; 朱光来; 陆同兴; 崔执凤

    2008-01-01

    Based on the whole zero field splitting (zfs) inte raction of triplet molecule in the interaction Hamiltonian of stable radicals and excited triplet molecules complexes, the intensity of chemical induced dynamic electron polarization (CIDEP) originated from RTPM were theoretically calculated in detail. In the calculation, the second order perturbation theory and the motion equation are used. The result of calculation indicates that the polarization pattern is hyperfine related E+E/A or A+A/E pattern, in which the net emissive or net absorptive polarization results from the zero field splitting (zfs) and the E/A or A/E polarization results from hyperfine (hf) interactions of the radical. Furthermore, the zero field splitting interaction E(S2Tξ-S2Tη) makes the net polarization decrease and the hyperfine dependent polarization increase.%基于考虑含E(S2Tξ-S2Tη) 项的相互作用全哈密顿,利用密度矩阵运动方程,对自由基-三重态对机理的CIDEP强度进行了详细的理论计算.计算结果表明:四重态母体自由基-三重态机理(QP-RTPM)和二重态母体自由基-三重态机理(DP-RTPM)分别使稳定自由基形成发射+发射/吸收(E+E/A)和吸收+吸收/发射(A+A/E)型多重性极化,其中净E(A)极化由零场分裂相互作用产生,超精细相关E/A(A/E)极化由超精细相互作用产生.另外,零场分裂相互作用项E(S2Tξ-S2Tη) ,使稳定自由基的净极化减弱,超精细相关极化加强.

  7. Nonadiabatic Effects of Atomic Coherence on Laser Intensity Fluctuations in Electromagnetically Induced Transparency

    Institute of Scientific and Technical Information of China (English)

    XU Qing; HU Xiang-Ming

    2011-01-01

    In an electromagnetically induced transparency system,the atoms have long-lived coherence compared to the cavity lifetime and interact nonadiabatically with the laser fields.We show that the high frequency fluctuations of both the intensities and the intensity difference can be squeezed below the shot noise limit due to the nonadiabatic effects.This noise squeezing can be used to enhance the precision in the short time measurements based on the intensities or the intensity difference.

  8. TASKS OF THE "INTENSIVE READING"

    Institute of Scientific and Technical Information of China (English)

    伍向梅

    1984-01-01

    @@ To Chinese students who are learning English as a foreign language, the "intensive reading" course is of great practical value,especially in the intermediate stage,i.e.senior-middle school or the second or third year in college. "Intensive reading"implies the recognition of the configuration, pronunciation, grammatical inflexion and structure of words, sentences, paragraphs, and the whole text. It strength ens listening and speaking, affords language, content, and models for writing.It helps the student lay a solid foundation of the language. Thus, the tasks assigned to the "intensive reading" are worth studying.

  9. Active Provenance in Data-intensive Research

    Science.gov (United States)

    Spinuso, Alessandro; Mihajlovski, Andrej; Filgueira, Rosa; Atkinson, Malcolm

    2017-04-01

    Scientific communities are building platforms where the usage of data-intensive workflows is crucial to conduct their research campaigns. However managing and effectively support the understanding of the 'live' processes, fostering computational steering, sharing and re-use of data and methods, present several bottlenecks. These are often caused by the poor level of documentation on the methods and the data and how users interact with it. This work wants to explore how in such systems, flexibility in the management of the provenance and its adaptation to the different users and application contexts can lead to new opportunities for its exploitation, improving productivity. In particular, this work illustrates a conceptual and technical framework enabling tunable and actionable provenance in data-intensive workflow systems in support of reproducible science. It introduces the concept of Agile data-intensive systems to define the characteristic of our target platform. It shows a novel approach to the integration of provenance mechanisms, offering flexibility in the scale and in the precision of the provenance data collected, ensuring its relevance to the domain of the data-intensive task, fostering its rapid exploitation. The contributions address aspects of the scale of the provenance records, their usability and active role in the research life-cycle. We will discuss the use of dynamically generated provenance types as the approach for the integration of provenance mechanisms into a data-intensive workflow system. Enabling provenance can be transparent to the workflow user and developer, as well as fully controllable and customisable, depending from their expertise and the application's reproducibility, monitoring and validation requirements. The API that allows the realisation and adoption of a provenance type is presented, especially for what concerns the support of provenance profiling, contextualisation and precision. An actionable approach to provenance

  10. High intensity protons in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.; Ahrens, L.; Blaskiewicz, M.; Brennan, J. M.; Drees, K. A.; Fischer, W.; Huang, H.; Minty, M.; Robert-Demolaize, G.; Thieberger, P.; Yip, K.

    2012-01-05

    During the 2012 summer shutdown a pair of electron lenses will be installed in RHIC, allowing the beam-beam parameter to be increased by roughly 50 percent. To realize the corresponding luminosity increase bunch intensities have to be increased by 50 percent, to 2.5 {center_dot} 10{sup 11} protons per bunch. We list the various RHIC subsystems that are most affected by this increase, and propose beam studies to ensure their readiness. The proton luminosity in RHIC is presently limited by the beam-beam effect. To overcome this limitation, electron lenses will be installed in IR10. With the help of these devices, the headon beam-beam kick experienced during proton-proton collisions will be partially compensated, allowing for a larger beam-beam tuneshift at these collision points, and therefore increasing the luminosity. This will be accomplished by increasing the proton bunch intensity from the presently achieved 1.65 {center_dot} 10{sup 11} protons per bunch in 109 bunches per beam to 2.5 {center_dot} 10{sup 11}, thus roughly doubling the luminosity. In a further upgrade we aim for bunch intensities up to 3 {center_dot} 10{sup 11} protons per bunch. With RHIC originally being designed for a bunch intensity of 1 {center_dot} 10{sup 11} protons per bunch in 56 bunches, this six-fold increase in the total beam intensity by far exceeds the design parameters of the machine, and therefore potentially of its subsystems. In this note, we present a list of major subsystems that are of potential concern regarding this intensity upgrade, show their demonstrated performance at present intensities, and propose measures and beam experiments to study their readiness for the projected future intensities.

  11. Interactions of astringent substances.

    Science.gov (United States)

    Lawless, H T; Corrigan, C J; Lee, C B

    1994-04-01

    Two-component mixtures of astringent materials were rated for perceived intensity of astringent and taste attributes over time. Components included alum (a complex salt), gallic acid (the monomeric component of hydrolyzable tannins), catechin (the monomeric component of condensed tannins) and citric acid. Mixtures of alum and gallic acid showed mixture suppression, in that the 50/50 mixture was less intense than either component in astringency, drying, roughing and puckery/drawing sensations. Suppression was seen at concentration levels producing moderate to strong astringency but was absent or less pronounced at lower concentration levels. A similar pattern held for citric acid, although the suppressive effects were less pronounced. Catechin and gallic acid mixtures were additive. Sensory interactions between astringent materials appears to depend on the substances involved and their concentrations (or intensity levels).

  12. 基于GSH-CdTe/CdS量子点的荧光变化研究hsDNA与盐酸洛美沙星-Cu(Ⅱ)配合物的相互作用%Interaction of Herring Sperm DNA with Lomefloxacin Hydrochloride-Cu(Ⅱ) Based on Changes in the Fluorescence Intensity of GSH-CdTe/CdS Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    沈益忠; 刘绍璞; 殷鹏飞; 何佑秋

    2013-01-01

    Glutathione (GSH)-capped CdTe/CdS quantum dots(GSH-CdTe/CdS QDs) were synthesized in aqueous solution.The particle sizes and morphological characteristics of GSH-CdTe/CdS QDs were investigated by transmission electron microscopy(TEM).The results exhibits that the particle size of as-prepared QDs has a narrow size distribution and good dispersivity.In Tris-HCl buffer medium (pH =7.6),lomefloxacin hydrochloride-Cu (Ⅱ) coordination compound(LMFH-Cu2+) was adsorbed to the surfaces of GSH-CdTe/CdS QDs through electrostatic attraction and formed ground state complex,which resulted in the quenching of the fluorescence of GSH-CdTe/CdS QDs.Adding herring sperm DNA (hsDNA) to GSH-CdTe/CdS QDs-LMFH-Cu(Ⅱ) system led to the fluorescence intensity of GSH-CdTe/CdS QDs recover,which can be explained by that the addition of hsDNA to the system induced LMFH-Cu(Ⅱ) to dissociate from the surface of GSH-CdTe/CdS QDs and embed into its double helix structure.According to the fluorescence quenching and restoration for GSH-CdTe/CdS QDs,fluorescence reversible control of GSH-CdTe/CdS QDs was realized.Compared with the interaction between GSH-CdTe/CdS QDs and LMFH,the interaction of GSH-CdTe/CdS QDs-LMFH-Cu (Ⅱ)-hsDNA was studied by fluorescence (FL),resonance Rayleigh scattering(RRS) and ultraviolet-visible absorption (UV-Vis) spectra.Meanwhile,the interaction mechanism was discussed and corresponding model of interaction was built.%采用水相法合成了谷胱甘肽(GSH)修饰的CdTe/CdS量子点(GSH-CdTe/CdS QDs).透射电子显微镜表征结果表明,GSH-CdTe/CdS QDs的粒径分布均匀,分散性好.在Tris-HCl(pH=7.6)缓冲液中,由于静电引力作用,带正电的盐酸洛美沙星(LMFH)-Cu(Ⅱ)配合物[LMFH-Cu(Ⅱ)]吸附到带负电的GSH-CdTe/CdSQDs表面形成基态复合物,导致GSH-CdTe/CdS QDs的荧光猝灭.随后,向GSH-CdTe/CdS QDs-LMFH-Ca(Ⅱ)配合物体系中加入鲱鱼精DNA(hsDNA),hsDNA可诱导LMFH-Cu(Ⅱ)配合物从GSH-CdTe/CdS QDs表面脱落而嵌

  13. Limitations in intense exercise performance of athletes - effect of speed endurance training on ion handling and fatigue development

    DEFF Research Database (Denmark)

    Hostrup, Morten; Bangsbo, Jens

    2016-01-01

    Mechanisms underlying fatigue development and limitations for performance during intense exercise have been intensively studied during the past couple of decades. Fatigue development may involve several interacting factors and depends on type of exercise undertaken and training level...... and power output during intense exercise. Regular speed endurance training (SET), i.e. exercise performed at intensities above that corresponding to maximum oxygen consumption (VO2max ), enhances intense exercise performance. However, most of the studies that have provided mechanistic insight...

  14. Proton Acceleration Drived by High-intensity Ultraviolet Laser

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The generation of energetic protons from a solid thin-foil by the interactions of ultra-short and intense laser pulses is investigated in numerous experiments in the last decade. The energetic proton beams are promising candidates for proton fast ignitor (PFI)

  15. Intensive family preservation services in Flanders : An outcome study

    NARCIS (Netherlands)

    Van Puyenbroeck, Hubert; Loots, Gerrit; Grietens, Hans; Jacquet, Wolfgang; Vanderfaeillie, Johan; Escudero, Valentin

    Set up as a one-group pre-test-post-test follow-up design, this study examines the outcomes of intensive family preservation services (IFPS) in Flanders addressing the following research questions: Does IFPS make a significant difference concerning (1) the interaction between parent and child? (2)

  16. Intense harmonics generation with customized photon frequency and optical vortex

    Science.gov (United States)

    Zhang, Xiaomei; Shen, Baifei; Shi, Yin; Zhang, Lingang; Ji, Liangliang; Wang, Xiaofeng; Xu, Zhizhan; Tajima, Toshiki

    2016-08-01

    An optical vortex with orbital angular momentum (OAM) enriches the light and matter interaction process, and helps reveal unexpected information in relativistic nonlinear optics. A scheme is proposed for the first time to explore the origin of photons in the generated harmonics, and produce relativistic intense harmonics with expected frequency and an optical vortex. When two counter-propagating Laguerre-Gaussian laser pulses impinge on a solid thin foil and interact with each other, the contribution of each input pulse in producing harmonics can be distinguished with the help of angular momentum conservation of photons, which is almost impossible for harmonic generation without an optical vortex. The generation of tunable, intense vortex harmonics with different photon topological charge is predicted based on the theoretical analysis and three-dimensional particle-in-cell simulations. Inheriting the properties of OAM and harmonics, the obtained intense vortex beam can be applied in a wide range of fields, including atom or molecule control and manipulation.

  17. Infrared intensity of 1-monolaurin-water systems in the gel phase

    Science.gov (United States)

    Kanesaka, Isao; Ishizaka, Makiko; Shimizu, Kunihiko

    2000-11-01

    The infrared spectra of 1-monolaurin-water systems, where KSCN is added as the intensity standard, were observed and the infrared intensity of the bands due to acyl groups measured relatively to that of the CN stretching. The infrared intensities of the bands parallel and perpendicular to the paraffin chains decrease and increase, respectively, on going from the crystalline β phase to the gel phase, confirming that these intensity changes result from the long-range interaction among oscillating dipoles. The infrared spectra with no CH 2 rocking and the splitting of the CH 2 rocking are also discussed with the same interaction model.

  18. [The future of intensive medicine].

    Science.gov (United States)

    Palencia Herrejón, E; González Díaz, G; Mancebo Cortés, J

    2011-05-01

    Although Intensive Care Medicine is a young specialty compared with other medical disciplines, it currently plays a key role in the process of care for many patients. Experience has shown that professionals with specific training in Intensive Care Medicine are needed to provide high quality care to critically ill patients. In Europe, important steps have been taken towards the standardization of training programs of the different member states. However, it is now necessary to take one more step forward, that is, the creation of a primary specialty in Intensive Care Medicine. Care of the critically ill needs to be led by specialists who have received specific and complete training and who have the necessary professional competences to provide maximum quality care to their patients. The future of the specialty presents challenges that must be faced with determination, with the main objective of meeting the needs of the population.

  19. Nanostructured intense-laser cleaner

    CERN Document Server

    Li, Xiao Feng; Kong, Qing; Wang, Ping Xiao; Yu, Qin; Gu, Yan Jan; Qu, Jun Fan

    2016-01-01

    A nanostructured target is proposed to enhance an intense-laser contrast: when a laser prepulse is injected on a nanostructured solid target surface, the prepulse is absorbed effectively by the nanostructured surface. The nanostructure size should be less than the laser wavelength. After the prepulse absorption, the front part of the main pulse destroys the microstructure and makes the surface a flat plasma mirror. The body of the main pulse is reflected almost perfectly. Compared with the plasma mirrors, the nanostructured surface is effective for the absorption of the intense laser prepulse, higher than 10^14 W/cm2. By the nanostructured laser cleaner, the laser pulse contrast increases about a hundredfold. The nanostructured laser cleaner works well for near-future intense lasers.

  20. Raman spectroscopy an intensity approach

    CERN Document Server

    Guozhen, Wu

    2017-01-01

    This book summarizes the highlights of our work on the bond polarizability approach to the intensity analysis. The topics covered include surface enhanced Raman scattering, Raman excited virtual states and Raman optical activity (ROA). The first chapter briefly introduces the Raman effect in a succinct but clear way. Chapter 2 deals with the normal mode analysis. This is a basic tool for our work. Chapter 3 introduces our proposed algorithm for the Raman intensity analysis. Chapter 4 heavily introduces the physical picture of Raman virtual states. Chapter 5 offers details so that the readers can have a comprehensive idea of Raman virtual states. Chapter 6 demonstrates how this bond polarizability algorithm is extended to ROA intensity analysis. Chapters 7 and 8 offer details on ROA, showing many findings on ROA mechanism that were not known or neglected before. Chapter 9 introduces our proposed classical treatment on ROA which, as combined with the results from the bond polarizability analysis, leads to a com...

  1. Low intensity transcranial electric stimulation

    DEFF Research Database (Denmark)

    Antal, Andrea; Alekseichuk, I; Bikson, M

    2017-01-01

    Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears...... following stimulation as well as prickling and burning sensations occurring during tDCS at peak-to-baseline intensities of 1-2mA and during tACS at higher peak-to-peak intensities above 2mA. The prevalence of published AEs is different in studies specifically assessing AEs vs. those not assessing them......, being higher in the former. AEs are frequently reported by individuals receiving placebo stimulation. The profile of AEs in terms of frequency, magnitude and type is comparable in healthy and clinical populations, and this is also the case for more vulnerable populations, such as children, elderly...

  2. Sound intensity and its measurement

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    1997-01-01

    The paper summarises the basic theory of sound intensity and its measurement and gives an overview of the state of the art with particular emphasis on recent developments in the field. Eighty references are given, most of which to literature published in the past two years. The paper describes...... and discusses the sources of error in measurement of sound intensity and the resulting limitations imposed on various applications of such measurements. Finally, some unresolved problems are mentioned, and the possibility of improving the instrumentation is discussed....

  3. [Physiotherapy in intensive care medicine].

    Science.gov (United States)

    Nessizius, S

    2014-10-01

    A high amount of recently published articles and reviews have already focused on early mobilisation in intensive care medicine. However, in the clinical setting the problem of its practicability remains as each professional group in the mobility team has its own expectations concerning the interventions made by physiotherapy. Even though there are as yet no standard operation procedures (SOP), there do exist distinctive mobilisation concepts that are well implemented in certain intensive care units (http://www.fruehmobilisierung.de/Fruehmobilisierung/Algorithmen.html). Due to these facts and the urgent need for SOPs this article presents the physiotherapeutic concept for the treatment of patients in the intensive care unit which has been developed by the author: First the patients' respiratory and motor functions have to be established in order to classify the patients and allocate them to their appropriate group (one out of three) according to their capacities; additionally, the patients are analysed by checking their so-called "surrounding conditions". Following these criteria a therapy regime is developed and patients are treated accordingly. By constant monitoring and re-evaluation of the treatment in accordance with the functions of the patient a dynamic system evolves. "Keep it simple" is one of the key features of that physiotherapeutic concept. Thus, a manual for the classification and the physiotherapeutic treatment of an intensive care patient was developed. In this article it is demonstrated how this concept can be implemented in the daily routine of an intensive care unit. Physiotherapy in intensive care medicine has proven to play an important role in the patients' early rehabilitation if the therapeutic interventions are well adjusted to the needs of the patients. A team of nursing staff, physiotherapists and medical doctors from the core facility for medical intensive care and emergency medicine at the medical university of Innsbruck developed the

  4. Music Inside an Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Ana Maria Loureiro De Souza Delabary

    2004-07-01

    Full Text Available This paper reports on the music therapy work performed in the intensive care unit of a university hospital. Clinical practice is inserted with in the hospital psychology department and acts jointly with some of the other health departments in the same hospital. The text presents the employed methodology, techniques, and repertoire, along with some considerations, comments, and observations on the practical side of the treatment. Music therapy imposes itself as a valuable element for the health area and becomes particularly meaningful as a part of the hospital's humanization program which is being developed in the institution. Striving for care quality, all the while it helps integrating all involved personnel interacting with the patients, music can be a powerful stimulus for the improvement of health care, particularly in the reception and support of the difficult situations terminal patients are faced with.

  5. Spectral intensity distribution of trapped fermions

    Indian Academy of Sciences (India)

    Sudeep Kumar Ghosh

    2015-10-01

    To calculate static response properties of a many-body system, local density approximation (LDA) can be safely applied. But, to obtain dynamical response functions, the applicability of LDA is limited bacause dynamics of the system needs to be considered as well. To examine this in the context of cold atoms, we consider a system of non-interacting spin-$\\frac{1}{2}$ fermions confined by a harmonic trapping potential. We have calculated a very important response function, the spectral intensity distribution function (SIDF), both exactly and using LDA at zero temperature and compared with each other for different dimensions, trap frequencies and momenta. The behaviour of the SIDF at a particular momentum can be explained by noting the behaviour of the density of states (DoS) of the free system (without trap) in that particular dimension. The agreement between exact and LDA SIDFs becomes better with increase in dimensions and number of particles.

  6. Forward-backward correlations between intensive observables

    CERN Document Server

    Kovalenko, Vladimir

    2016-01-01

    We demonstrate that the investigations of the forward-backward correlations between intensive observables enable to obtain more clear signal about the initial stage of hadronic interaction, e.g. about the process of string fusion, compared to usual forward-backward multiplicity correlations. As an example, the correlation between mean-event transverse momenta of charged particles in separated rapidity intervals is considered. We performed calculations in the framework of dipole-based Monte Carlo string fusion model. We obtained the dependence of the correlation strength on the collision centrality for different initial energies and colliding systems. It is shown that the dependence reveals the decline of the correlation coefficient for most central Pb-Pb collisions at LHC energy. We compare the results both with the ones obtained in alternative models and with the ones obtained by us using various MC generators.

  7. Intensity-intensity and intensity-amplitude correlation of microwave photons from a superconducting artificial atom

    Science.gov (United States)

    Wang, Fei; Feng, Xunli; Oh, C. H.

    2016-10-01

    We investigate the dynamics of the microwave-frequency nonclassical correlations in a three-level Δ -configuration artificial atom, which is realized by superconducting quantum circuits. The intensity-intensity correlation and intensity field are strongly dependent on the relative phase Φ of the driven fields. It is found that two interference loops are formed in the dressed state picture at Φ =0 or π, which are responsible for the generation of nonclassical microwave photons. When the phase is changed into Φ =π /2 or 3π /2 , the temporal correlation functions exhibit different oscillating behaviors. The phase-sensitive nonclassical correlations of fluorescence photons may find practical application in the design of all-optical switches and quantum information processing.

  8. Sound intensity and its measurement

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    1997-01-01

    The paper summarises the basic theory of sound intensity and its measurement and gives an overview of the state of the art with particular emphasis on recent developments in the field. Eighty references are given, most of which to literature published in the past two years. The paper describes...

  9. Intensive care of haematological patients

    DEFF Research Database (Denmark)

    Magid, Tobias; Haase, Nicolai; Andersen, Jakob Steen

    2012-01-01

    This article presents the treatment results of 320 consecutive patients with malignant haematological diagnoses admitted to a tertiary intensive care unit at a Danish University hospital over a six-year period (2005-2010). With reference to international publications, we describe the development...

  10. Perceiving the Intensity of Light

    Science.gov (United States)

    Purves, Dale; Williams, S. Mark; Nundy, Surajit; Lotto, R. Beau

    2004-01-01

    The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, "illusions" such as simultaneous brightness contrast, Mach bands,…

  11. How is intensive care reimbursed?

    DEFF Research Database (Denmark)

    Bittner, Martin-Immanuel; Donnelly, Maria; van Zanten, Arthur Rh

    2013-01-01

    Reimbursement schemes in intensive care are more complex than in other areas of healthcare, due to special procedures and high care needs. Knowledge regarding the principles of functioning in other countries can lead to increased understanding and awareness of potential for improvement. This can ...

  12. Intensity of smiling and attractiveness as facial signals of trustworthiness in women.

    Science.gov (United States)

    Schmidt, K; Levenstein, R; Ambadar, Z

    2012-06-01

    Facial attractiveness is associated with a variety of positive social characteristics including trustworthiness. Variations in smiling, such as the appearance of the Duchenne marker and increased intensity of expression, have likewise been linked with positive judgments of trustworthiness. The study investigated the interaction of the effects of models' attractiveness and their smiling intensity on impressions of perceived trustworthiness. Participants rated the attractiveness and expressivity of neutral, low intensity, and high intensity smiling images of 45 women models. These images were also presented to a second group of participants who rated trustworthiness. Repeated measures analysis of covariance of the effects of attractiveness and manipulated smile intensity on trustworthiness indicated a main effect for smile intensity: increased smile intensity was associated with greater trustworthiness. Attractiveness also contributed to rated trustworthiness independently of smiling intensity. Results suggested there is an additional contribution of facial expression in creating social impressions of trustworthiness.

  13. Grid-Enabled Interactive Data Language for Astronomical Data Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Grid technologies provide a valuable solution for data intensive scientific applications but are not readily available for astronomical data and Interactive Data...

  14. Electroweak interactions at LEP

    CERN Document Server

    Swain, J D

    2000-01-01

    The electroweak interactions are based on an extension of the electromagnetic (Maxwell) interactions, realized in a rather odd way so that the symmetries of the theory are not immediately obvious. This "broken" theory has been the subject of intense investigation at LEP, and has passed all tests with flying colours. These lectures are meant to complement the many excellent presentations of the standard SU(2)/sub L/*U(1)/sub Y/ electroweak interactions in three main ways: first to clarify the physical meaning of symmetries in particle physics, second, to summarize the recent tests of the standard model using LEP data, and finally to look at possible roles of gravity in understanding mass. (10 refs).

  15. Use intensity of social networks in southern Brazil

    Directory of Open Access Journals (Sweden)

    Rafaele Matte Wojahn

    2017-08-01

    Full Text Available A social network implies in connect people. This article aims to identify the use intensity of social network in Southern Brazil. The research was characterized by quantitative approach, descriptive, cross-sectional and survey, with a sample of 372 respondents. To data analysis was used descriptive analysis to characterize the sample, verify the access frequency of social networks and the daily access time, and Pearson’s Correlation to identify the daily access time and the social networks. The results indicated the social network used in more intensity is the Facebook and then Whatsapp, and the access occurs at home. However, all the social networks promote interactions toward users.

  16. Infrared intensity and morphology of l-monolaurin-water systems.

    Science.gov (United States)

    Kanesaka, I; Shimizu, K

    2000-02-15

    The infrared spectra for some metastable states in 1-monolaurin water systems were observed at room temperature, where the relative intensity of bands due to paraffin chains changed considerably, especially in the CH2 rockings, which disappear in some cases. It is considered that the spectral changes result from the morphology change on going from the crystal to the liquid crystal, smectic B phase, so-called gel phase, which consists of the lipid bilayers with ordered paraffin chains alternating with water layers. The model for explaining the intensity change is proposed on the basis of the interaction among oscillating dipoles.

  17. Infrared intensity and morphology of 1-monolaurin-water systems

    Science.gov (United States)

    Kanesaka, Isao; Shimizu, Kunihiko

    2000-02-01

    The infrared spectra for some metastable states in 1-monolaurin-water systems were observed at room temperature, where the relative intensity of bands due to paraffin chains changed considerably, especially in the CH 2 rockings, which disappear in some cases. It is considered that the spectral changes result from the morphology change on going from the crystal to the liquid crystal, smectic B phase, so-called gel phase, which consists of the lipid bilayers with ordered paraffin chains alternating with water layers. The model for explaining the intensity change is proposed on the basis of the interaction among oscillating dipoles.

  18. Relações e interações no ambiente de cuidados em Unidade de Terapia Intensiva Relaciones e interacciones en el ambiente de cuidados en una Unidad de Cuidados Intensivos Relationships and interactions in the Intensive Care Unit environment of care

    Directory of Open Access Journals (Sweden)

    Marli Terezinha Stein Backes

    2012-01-01

    Full Text Available OBJETIVO: Discutir as relações e interações do ambiente de cuidados em Unidade de Terapia Intensiva (UTI. MÉTODOS: Estudo de abordagem qualitativa foi fundamentado na "Grounded Theory". Foram entrevistados 47 sujeitos diferenciados de três UTIs Adulto, localizadas em Florianópolis/SC, Santa Maria/RS e Pelotas/RS, entre junho de 2009 e setembro de 2010. RESULTADOS: Neste estudo, são apresentadas e discutidas duas categorias: "A rede de apoio, a ordem/desordem e perturbações no ambiente de UTI"; "Convivendo com certezas, incertezas e contradições no ambiente de UTI". CONCLUSÃO: Considera-se necessário compreender o ambiente de UTI a partir de uma visão sistêmica. E isso significa acolher a circularidade e dinamicidade de ordem-desordem-organização que continuamente (re alimentam as relações e interações humanas e profissionais nesse ambiente.OBJETIVO: Discutir las relaciones e interacciones del ambiente de cuidados en una Unidad de Cuidados Intensivos (UTI. MÉTODOS: Estudio de abordaje cualitativo fundamentado en la "Grounded Theory". Entrevistamos a 47 personas en tres unidades de cuidados intensivos de adultos diferente, localizadas en Florianópolis/SC, Santa Maria/RS y Pelotas/RS, entre junio de 2009 y setiembre de 2010. RESULTADOS: En este estudio, se presentan y discuten dos categorías: "La red de apoyo, el orden/desorden y perturbaciones en el ambiente de UCI" y "Conviviendo con certezas, incertidumbres y contradicciones en el ambiente de UCI". CONCLUSIÓN: Se considera necesario comprender el ambiente de UCI a partir de una visión sistémica. Y eso significa acoger la circularidad y dinamicidad de orden-desorden-organización que continuamente (re alimentan las relaciones e interacciones humanas y profesionales en ese ambiente.OBJECTIVE: To discuss relationships and interactions in the Intensive Care Unit's (ICU environment of care. METHODS: A qualitative study that was based on grounded theory. We interviewed 47

  19. Sound intensity radiated by Gaohu

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Gaohu is one of the main bowed stringed instruments used in Guangdong music and Chinese native Orchestra. However its sound intensity has never been carefully measured. In this paper the sound power measurements of Gaohu were performed in a reverberation chamber according to the Chinese national standard. Two qualified musicians performed on their own instruments. The mean sound power levels and the dynamic ranges of Gaohu were investigated by four channel acoustic measuring equipments when single notes, music scale and melodies were performed under pp, mp, f and ff dynamics. Great differences were found when Gaohu performed single notes, while the sound power levels were quite close when music scale were performed under f dynamic to those when melodies were performed under normal dynamic mark, the sound power levels of Gaohu when music scale was performed under f dynamics were suggested as the typical and representative value of the sound intensities of Gaohu instrument.

  20. IN DEFENCE OF INTENSIVE READING

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    In his article‘Why Intensive Reading Hinders the Development of Both English Language Teachingand English Language Learning in China’.Ian Cotton.a British lecturer in Chongqing University,concludes thai the teaching method of Intensive Reading(IR)in China is mainly responsible for the,comparatively low level of Chinese students skills in listening and speaking.He believes IRcontributes nothing to the development of English language teaching and learning in China.Such aconclusion,in my.opinion,is extreme and does not reflect the actual situation of ELT in China.Infact.IR has proved to be an effective teaching method to improve students’English.The question ishow to use the method effectively.

  1. CIM—Compact intensity modulation

    Science.gov (United States)

    Bleuel, M.; Lang, E.; Gähler, R.; Lal, J.

    2008-07-01

    Compact intensity modulation (CIM), a new method to modulate the intensity of a neutron beam is demonstrated. CIM allows the production of arbitrary signals where the focus point can be chosen and changed without any constraints. A novel feature in this technique compared to spin echo techniques is that the neutron polarization is kept parallel or anti-parallel to the static fields during the passage through the magnetic fields and the beating pattern at the detector is produced by an amplitude modulation (AM) of the adiabatic RF-spin flippers rather than Larmor precession like in neutron spin echo (NSE) instruments; thus, the achievable contrast is very high and the instrument resolution can be changed very quickly. This gives the fascinating possibility at pulsed neutron sources to sweep the modulation frequency of the flippers in order to increase dynamic resolution range during the same neutron pulse.

  2. Ultrahigh-intensity inverse bremsstrahlung

    Science.gov (United States)

    Kostyukov, I. Yu.; Rax, J.-M.

    1999-01-01

    We study inverse bremsstrahlung in the ultrahigh intensity relativistic regime. The fully relativistic ultrahigh intensity absorption (emission) coefficient is derived for an arbitrary scattering potential and small-angle scattering. We find that in the Coulomb field case this absorption (emission) coefficient can be calculated as a function of the quiver energy, drift momentum, and impact parameter in two complementary regimes: (i) for remote collisions when the impact parameter is larger than the amplitude of the quiver motion, and (ii) for instantaneous collisions when the scattering time is shorter than the period of the wave. Both circular and linear polarizations are considered, and this study reveals that in this relativistic regime inverse bremsstrahlung absorption can be viewed as a harmonic Compton resonance heating of the laser-driven electron by the virtual photon of the ion Coulomb field. The relativistic modification of Marcuse's effect [Bell Syst. Tech. J. 41, 1557 (1962)] are also discussed, and relations with previous nonrelativistic results are elucidated.

  3. Neutrino physics with an intense \

    CERN Document Server

    Henning, R

    2010-01-01

    We study some of the physics potential of an intense $1\\,\\mathrm{MCi}$ $^{51}\\mathrm{Cr}$ source combined with the {\\sc Majorana Demonstrator} enriched germanium detector array. The {\\sc Demonstrator} will consist of detectors with ultra-low radioactive backgrounds and extremely low energy thresholds of~$\\sim 400\\,\\mathrm{eV}$. We show that it can improve the current limit on the neutrino magnetic dipole moment. We briefly discuss physics applications of the charged-current reaction of the $^{51}\\mathrm{Cr} neutrino with the $^{73}\\mathrm{Ge} isotope. Finally, we argue that the rate from a realistic, intense tritium source is below the detectable limit of even a tonne-scale HPGe experiment

  4. Intensive temperature and quantum correlations

    CERN Document Server

    Ferraro, Alessandro; Acin, Antonio

    2011-01-01

    We consider quantum systems of coupled harmonic oscillators and study the question of whether temperature is an intensive quantity, in the sense that a block of a thermal state can be approximated by an effective thermal state at the same temperature as the whole system. We identify instances in which this approximation is not valid, as the block state and the reference thermal state are distinguishable. Contrary to the standard thermodynamic intuition, this distinguishability may even increase with the block size. However, we also show that the two states do become less distinguishable with the block size for standard coarse-grained measurements. Finally, we point out the role entanglement plays in this problem: in general, the thermodynamic paradigm of local intensive temperature applies whenever entanglement is not present in the system.

  5. Pediatric intensive care in Argentina.

    Science.gov (United States)

    Schnitzler, E J

    1993-09-01

    8.2% of the gross domestic product is spent annually on health care in Argentina, a country of 32 million people. There is 1 medical doctor of every 147,000 beds in a total 3180 hospitals. The infant mortality rate in Argentina is 24.5/1000 live births which is high compared to developed countries. Perinatal causes and congenital anomalies are the main cause of death after the neonatal period, and accidents, cardiac disease, and respiratory tract infections are the main causes of death among children over age 1 year. Argentina has approximately 35 pediatric intensive care units (ICU), but 154 of 244 beds are within or near the capital. Only 2 hospitals have pediatric intensive care fellowship programs, so full time dedicated staff is rare. 250 registered pediatricians dedicated to intensive care are in the Argentine Pediatric Society and the nurse/bed ratio is 1:2-1:3. Moreover, the country has neither postanesthesia recuperation units, burn units, chronic ventilation units, nor approved home assistance programs, and intermediate care is not clearly standardized. These inadequacies have led to a shortage of beds and the caring for of critically ill children in general pediatric or emergency wards in hospitals which lack adequate equipment; patients are often discharged inappropriately to clear bed space. Even so, prehospital and emergency room care tends to be provided without the necessary coordination with the pediatric ICU, and structural conditions regarding electrical self-sufficiency, air conditioning, and circulation are met in only few units. Despite the existence of these adverse conditions for the care of critically ill children, a pediatric organ transplant program developed since 1987 has demonstrated 70% to 100% survival rates for 16l orthotopic liver and 9 heart transplants, respectively. Alternatives to improving intensive care in Argentina include optimizing the response of emergency and critical care delivery systems, categorizing hospitals and

  6. INTENSIVE PROCESSES OF RETAIL INTERNATIONALIZATION

    OpenAIRE

    Ishak Mesic

    2010-01-01

    Integration and globalization of world market have resulted in trade internationalization, especially in the sector of retailing. Global trade, and in particular global retail, has become more intensive. Free European market has speeded up cross border retail expansion within European Union. Retail internationalization, with increased tempo, has redefined relationships in distribution channels on a global scale. Even though the speed of retail internationalization is, without a doubt, increas...

  7. IONIS: Approximate atomic photoionization intensities

    Science.gov (United States)

    Heinäsmäki, Sami

    2012-02-01

    A program to compute relative atomic photoionization cross sections is presented. The code applies the output of the multiconfiguration Dirac-Fock method for atoms in the single active electron scheme, by computing the overlap of the bound electron states in the initial and final states. The contribution from the single-particle ionization matrix elements is assumed to be the same for each final state. This method gives rather accurate relative ionization probabilities provided the single-electron ionization matrix elements do not depend strongly on energy in the region considered. The method is especially suited for open shell atoms where electronic correlation in the ionic states is large. Program summaryProgram title: IONIS Catalogue identifier: AEKK_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKK_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1149 No. of bytes in distributed program, including test data, etc.: 12 877 Distribution format: tar.gz Programming language: Fortran 95 Computer: Workstations Operating system: GNU/Linux, Unix Classification: 2.2, 2.5 Nature of problem: Photoionization intensities for atoms. Solution method: The code applies the output of the multiconfiguration Dirac-Fock codes Grasp92 [1] or Grasp2K [2], to compute approximate photoionization intensities. The intensity is computed within the one-electron transition approximation and by assuming that the sum of the single-particle ionization probabilities is the same for all final ionic states. Restrictions: The program gives nonzero intensities for those transitions where only one electron is removed from the initial configuration(s). Shake-type many-electron transitions are not computed. The ionized shell must be closed in the initial state. Running time: Few seconds for a

  8. LHC Report: reaching high intensity

    CERN Multimedia

    Jan Uythoven

    2015-01-01

    After both beams having been ramped to their full energy of 6.5 TeV, the last two weeks saw the beam commissioning process advancing on many fronts. An important milestone was achieved when operators succeeded in circulating a nominal-intensity bunch. During the operation, some sudden beam losses resulted in beam dumps at top energy, a problem that needed to be understood and resolved.   In 2015 the LHC will be circulating around 2800 bunches in each beam and each bunch will contain just over 1 x 1011 protons. Until a few days ago commissioning was taking place with single bunches of 5 x 109 protons. The first nominal bunch with an intensity of 1 x 1011 protons was injected on Tuesday, 21 April. In order to circulate such a high-intensity bunch safely, the whole protection system must be working correctly: collimators, which protect the aperture, are set at preliminary values known as coarse settings; all kicker magnets for injecting and extracting the beams are commissioned with beam an...

  9. Intense Collaboration In Globally Distributed Teams: Evolving Patterns Of Dependencies And Coordination

    NARCIS (Netherlands)

    K. Kumar (Kuldeep); P.C. van Fenema (Paul); M.A. von Glinow

    2004-01-01

    textabstractAs multi-national firms and major offshore outsourcing companies develop experience with global work, their globally distributed teams face the challenge of collaborating intensely without the common interaction advantages associated with collocated work. This chapter analyzes the

  10. Intense Collaboration In Globally Distributed Teams: Evolving Patterns Of Dependencies And Coordination

    OpenAIRE

    Kumar, Kuldeep; Fenema, Paul; Glinow, M.A.

    2004-01-01

    textabstractAs multi-national firms and major offshore outsourcing companies develop experience with global work, their globally distributed teams face the challenge of collaborating intensely without the common interaction advantages associated with collocated work. This chapter analyzes the sources of intense collaboration. It then introduces strategies that organizations have developed to reduce the intensity of collaboration (sequentializing work, using mediating artifacts, modularity), o...

  11. Mapping 3D focal intensity exposes the stable trapping positions of single nanoparticles

    DEFF Research Database (Denmark)

    Kyrsting, A.; Bendix, P.M.; Oddershede, L.B.

    2013-01-01

    The photonic interactions between a focused Gaussian laser beam and a nanoscopic particle are highly dependent on exact particle location and focal intensity distribution. So far, the 3D focal intensity distribution and the preferred position of a nanoparticle confined within the focal region were...... only theoretically predicted. Here, we directly map the three-dimensional focal intensity distribution, quantify stable trapping positions, and prove that certain sizes of nanoparticles stably trap in front of the focus. © 2012 American Chemical Society....

  12. Recognition of static and dynamic facial expressions: Influences of sex, type and intensity of emotion

    OpenAIRE

    2013-01-01

    Ecological validity of static and intense facial expressions in emotional recognition has been questioned. Recent studies have recommended the use of facial stimuli more compatible to the natural conditions of social interaction, which involves motion and variations in emotional intensity. In this study, we compared the recognition of static and dynamic facial expressions of happiness, fear, anger and sadness, presented in four emotional intensities (25 %, 50 %, 75 % and 100 %). Twenty volunt...

  13. The response of farmland bird communities to agricultural intensity as influenced by its spatial aggregation.

    Directory of Open Access Journals (Sweden)

    Félix Teillard

    Full Text Available The shape of the relationship between biodiversity and agricultural intensity determines the range of intensities that should be targeted by conservation policies to obtain the greatest environmental benefits. Although preliminary evidence of this relationship exists, the influence of the spatial arrangement of intensity on biodiversity remains untested. We conducted a nationwide study linking agricultural intensity and its spatial arrangement to a farmland bird community of 22 species. Intensity was described with a continuous indicator based on Input Cost per hectare, which was relevant for both livestock and crop production. We used the French Breeding Bird Survey to compute several descriptors of the farmland bird community along the intensity gradient and tested for the significance of an interaction effect between intensity and its spatial aggregation on these descriptors. We found that the bird community was comprised of both winner and loser species with regard to intensity. The community composition descriptors (trophic level, specialisation, and specialisation for grassland indices displayed non-linear relationships to intensity, with steeper slopes in the lower intensity range. We found a significant interaction effect between intensity and its spatial aggregation on the grassland specialisation index of the bird community; the effect of agricultural intensity was strengthened by its spatial aggregation. We suggest that an opportunity to improve the effectiveness of conservation policies exists by targeting measures in areas where intensity is moderate to low and aggregated. The effect of the aggregation of agricultural intensity on biodiversity should be considered in other scales and taxa when developing optimal policy targeting and intensity allocation strategies.

  14. Optimization of Axial Intensity Point Spread Function

    Institute of Scientific and Technical Information of China (English)

    WANG Haifeng; GAN Fuxi; CHEN Zhongyu

    2001-01-01

    It is known that for the converged laser beam, the axial intensity distribution corresponds to a Gaussian curve, that is, the intensity on the focal plane is the peak intensity. When it defocuses, the intensity would decrease rapidly. In optical data storage, for instance, we expect the intensity within a certain distance to be almost equal. In this paper, we propose to use a pure phase superresolution apodizer to optimize the axial intensity distribution of the converged laser beam and at the same time improve the resolution. The intensity point spread function remains almost identical in a wide range within the focal depth.

  15. Transmission Intensity and Drug Resistance in Malaria Population Dynamics : Implications for Climate Change

    NARCIS (Netherlands)

    Artzy-Randrup, Yael; Alonso, David; Pascual, Mercedes

    2010-01-01

    Although the spread of drug resistance and the influence of climate change on malaria are most often considered separately, these factors have the potential to interact through altered levels of transmission intensity. The influence of transmission intensity on the evolution of drug resistance has b

  16. Knowledge sharing behavior and intensive care nurse innovation: the moderating role of control of care quality

    DEFF Research Database (Denmark)

    Li-Ying, Jason; Paunova, Minna; Egerod, Ingrid

    2016-01-01

    quality within the unit. Conclusions The increasing pressures to implement the control of care quality and innovate may be conflicting, unless handled properly. Implications for nursing management Process control at intensive care units should be loosened, when personal interaction between intensive care...

  17. Planning the Future of U.S. Particle Physics (Snowmass 2013): Chapter 2: Intensity Frontier

    CERN Document Server

    Hewett, J L; Babu, K S; Butler, J; Casey, B; de Gouvea, A; Essig, R; Grossman, Y; Hitlin, D; Jaros, J; Kearns, E; Kumar, K; Ligeti, Z; Lu, Z -T; Pitts, K; Ramsey-Musolf, M; Ritchie, J; Scholberg, K; Wester, W; Zeller, G P

    2014-01-01

    These reports present the results of the 2013 Community Summer Study of the APS Division of Particles and Fields ("Snowmass 2013") on the future program of particle physics in the U.S. Chapter 2, on the Intensity Frontier, discusses the program of research with high-intensity beams and rare processes. This area includes experiments on neutrinos, proton decay, charged-lepton and quark weak interactions, atomic and nuclear probes of fundamental symmetries, and searches for new, light, weakly-interacting particles.

  18. The calculation of vibrational intensities in forbidden electronic transitions.

    Science.gov (United States)

    Johnson, Philip M; Xu, Haifeng; Sears, Trevor J

    2006-10-28

    A method is described for the use of electronic structure and Franck-Condon factor programs in the calculation of the vibrational intensities in forbidden electronic transitions. Using the B 2B2-X 2B1 electronic transition of benzonitrile cation as a test case, transition moments were calculated using the symmetry adapted cluster/configuration interaction method at various points along the normal mode displacements of the molecule, from which transition moment derivatives were obtained. The transition moments were found to vary almost linearly with respect to the normal mode displacements. Using these, along with Franck-Condon factors, an expansion of the transition moment with respect to the normal coordinates provides a measure of vibrational intensities, including the effects of geometry change and Duschinsky rotation [Acta Physicochim. URSS 7, 551 (1937)]. Second order terms in the moment expansion are calculated, and it is determined that they must be included if the intensity of combination bands is to be properly obtained.

  19. Stabilizing the intensity for a Hamiltonian model of the FEL

    CERN Document Server

    Bachelard, R; Fanelli, D; Leoncini, X; Vittot, M

    2008-01-01

    The intensity of an electromagnetic wave interacting self-consistently with a beam of charged particles, as in a Free Electron Laser, displays large oscillations due to an aggregate of particles, called the macro-particle. In this article, we propose a strategy to stabilize the intensity by destabilizing the macro-particle. This strategy involves the study of the linear stability of a specific periodic orbit of a mean-field model. As a control parameter - the amplitude of an external wave - is varied, a bifurcation occur in the system which has drastic effects on the self-consistent dynamics, and in particular, on the macro-particle. We show how to obtain an appropriate tuning of the control parameter which is able to strongly decrease the oscillations of the intensity without reducing its mean-value.

  20. Stabilizing the intensity for a Hamiltonian model of the FEL

    Energy Technology Data Exchange (ETDEWEB)

    Bachelard, R. [Centre de Physique Theorique, CNRS Luminy, Case 907, F-13288 Marseille Cedex 9 (France)], E-mail: bachelard@cpt.univ-mrs.fr; Chandre, C. [Centre de Physique Theorique, CNRS Luminy, Case 907, F-13288 Marseille Cedex 9 (France); Fanelli, D. [Theoretical Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom); Leoncini, X.; Vittot, M. [Centre de Physique Theorique, CNRS Luminy, Case 907, F-13288 Marseille Cedex 9 (France)

    2008-08-01

    The intensity of an electromagnetic wave interacting self-consistently with a beam of charged particles, as in a Free Electron Laser, displays large oscillations due to an aggregate of particles, called the macro-particle. In this article, we propose a strategy to stabilize the intensity by destabilizing the macro-particle. This strategy involves the study of the linear stability of a specific periodic orbit of a mean-field model. As a control parameter-the amplitude of an external wave-is varied, a bifurcation occurs in the system which has drastic effects on the self-consistent dynamics, and in particular, on the macro-particle. We show how to obtain an appropriate tuning of the control parameter which is able to strongly decrease the oscillations of the intensity without reducing its mean-value.

  1. Intense sweetness surpasses cocaine reward.

    Directory of Open Access Journals (Sweden)

    Magalie Lenoir

    Full Text Available BACKGROUND: Refined sugars (e.g., sucrose, fructose were absent in the diet of most people until very recently in human history. Today overconsumption of diets rich in sugars contributes together with other factors to drive the current obesity epidemic. Overconsumption of sugar-dense foods or beverages is initially motivated by the pleasure of sweet taste and is often compared to drug addiction. Though there are many biological commonalities between sweetened diets and drugs of abuse, the addictive potential of the former relative to the latter is currently unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that when rats were allowed to choose mutually-exclusively between water sweetened with saccharin-an intense calorie-free sweetener-and intravenous cocaine-a highly addictive and harmful substance-the large majority of animals (94% preferred the sweet taste of saccharin. The preference for saccharin was not attributable to its unnatural ability to induce sweetness without calories because the same preference was also observed with sucrose, a natural sugar. Finally, the preference for saccharin was not surmountable by increasing doses of cocaine and was observed despite either cocaine intoxication, sensitization or intake escalation-the latter being a hallmark of drug addiction. CONCLUSIONS: Our findings clearly demonstrate that intense sweetness can surpass cocaine reward, even in drug-sensitized and -addicted individuals. We speculate that the addictive potential of intense sweetness results from an inborn hypersensitivity to sweet tastants. In most mammals, including rats and humans, sweet receptors evolved in ancestral environments poor in sugars and are thus not adapted to high concentrations of sweet tastants. The supranormal stimulation of these receptors by sugar-rich diets, such as those now widely available in modern societies, would generate a supranormal reward signal in the brain, with the potential to override self

  2. Intensive treatment of leg lymphedema

    Directory of Open Access Journals (Sweden)

    Pereira de Godoy Jose

    2010-01-01

    Full Text Available Background: Despite of all the problems caused by lymphedema, this disease continues to affect millions of people worldwide. Thus, the identification of the most efficacious forms of treatment is necessary. Aim: The aim of this study was to evaluate a novel intensive outpatient treatment for leg lymphedema. Methods: Twenty-three legs of 19 patients were evaluated in a prospective randomized study. The inclusion criteria were patients with Grade II and III lymphedema, where the difference, measured by volumetry, between the affected limb below the knee and the healthy limb was greater than 1.5 kg. Intensive treatment was carried out for 6- to 8-h sessions in the outpatient clinic. Analysis of variance was utilized for statistical analysis with an alpha error of 5% (P-value < 0.05 being considered significant. Results: All limbs had significant reductions in size with the final mean loss being 81.1% of the volume of edema. The greatest losses occurred in the first week (P-value < 0.001. Losses of more than 90% of the lymphedema occurred in 9 (39.13% patients; losses of more than 80% in 13 (56.52%, losses of more than 70% in 17 (73.91% and losses of more than 50% were recorded for 95.65% of the patients; only 1 patient lost less than 50% (37.9% of the edema. Conclusion: The intensive treatment of lymphedema in the outpatient clinic can produce significant reductions in the volume of edema over a short period of time and can be recommended for any grade of lymphedema, in particular the more advanced degrees.

  3. [Intensive care medicine -- update 2005].

    Science.gov (United States)

    Flohé, S; Lendemans, S; Schmitz, D; Waydhas, C

    2006-06-01

    This manuscript gives a review about important studies addressing problems in intensive care medicine that have been published in journals focussing on critical care medicine and surgery in 2005. Only clinical studies are included in this review, mostly meta-analyses, randomized controlled trials and a few important or interesting observational studies. In addition to describing major results a critical appraisal of each study is undertaken, which, however, is neither comprehensive nor complete. It is merely intended to address some important aspects for the reader who should be stimulated to go deeper into one or the other topic or study. The publication of the new CPR-guidelines of the American Heart Association and the European Resuscitation Council as well as the newly developed SAPS III score to predict intensive care unit outcome are among the outstanding topics. Several randomized trials and meta-analyses deal with aspects of drug therapy of septic patients. Some important and relevant findings have been reported with respect to the efficiency of the open-lung concept, non-invasive ventilation, the use of heat and moisture exchanger filters compared to active humidifiers and of closed systems for endotracheal suctioning. The role of immuno-nutrition in adults and children as well as of early enteral nutrition can be defined more clearly. Whether corticosteroids should be used in the treatment of severe traumatic brain injury can be definitely answered now. There are some new insights reported into the management of patients infected or contaminated with MRSA in the intensive care unit. Last but not least an impressive study shows that not only the newest therapeutic developments but the stringent use of the already known treatment options may result in dramatic improvements of patient outcome.

  4. Neuroimaging craving: urge intensity matters.

    Science.gov (United States)

    Wilson, Stephen J; Sayette, Michael A

    2015-02-01

    Functional neuroimaging has become an increasingly common tool for studying drug craving. Furthermore, functional neuroimaging studies, which have addressed an incredibly diverse array of questions regarding the nature and treatment of craving, have had a substantial impact on theoretical models of addiction. Here, we offer three points related to this sizeable and influential body of research. First, we assert that the craving most investigators seek to study represents not just a desire but a strong desire to use drugs, consistent with prominent theoretical and clinical descriptions of craving. Secondly, we highlight that, despite the clear conceptual and clinical emphasis on craving as an intense desire, brain imaging studies often have been designed explicitly in a way that reduces the ability to generate powerful cravings. We illustrate this point by reviewing the peak urge levels endorsed by participants in functional magnetic resonance imaging (fMRI) studies of cigarette craving in nicotine-deprived versus non-deprived smokers. Thirdly, we suggest that brain responses measured during mild states of desire (such as following satiety) differ in fundamental ways from those measured during states of overpowering desire (i.e. craving) to use drugs. We support this position by way of a meta-analysis revealing that fMRI cue exposure studies using nicotine-deprived smokers have produced different patterns of brain activation to those using non-deprived smokers. Regarding brain imaging studies of craving, intensity of the urges matter, and more explicit attention to urge intensity in future work has the potential to yield valuable information about the nature of craving. © 2014 Society for the Study of Addiction.

  5. Explicit Interaction

    DEFF Research Database (Denmark)

    Löwgren, Jonas; Eriksen, Mette Agger; Linde, Per

    2006-01-01

    as an interpretation of palpability, comprising usability as well as patient empowerment and socially performative issues. We present a prototype environment for video recording during physiotherapeutical consultation which illustrates our current thoughts on explicit interaction and serves as material for further......We report an ongoing study of palpable computing to support surgical rehabilitation, in the general field of interaction design for ubiquitous computing. Through explorative design, fieldwork and participatory design techniques, we explore the design principle of explicit interaction...

  6. Floor interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Ludvigsen, Martin;

    2005-01-01

    Within architecture, there is a long tradition of careful design of floors. The design has been concerned with both decorating floors and designing floors to carry information. Ubiquitous computing technology offers new opportunities for designing interactive floors. This paper presents three...... different interactive floor concepts. Through an urban perspective it draws upon the experiences of floors in architecture, and provides a set of design issues for designing interactive floors....

  7. Photoelectric effect at ultrahigh intensities.

    Science.gov (United States)

    Sorokin, A A; Bobashev, S V; Feigl, T; Tiedtke, K; Wabnitz, H; Richter, M

    2007-11-23

    In the spectral range of the extreme ultraviolet at a wavelength of 13.3 nm, we have studied the photoionization of xenon at ultrahigh intensities. For our ion mass-to-charge spectroscopy experiments, irradiance levels from 10(12) to 10(16) W cm(-2) were achieved at the new free-electron laser in Hamburg FLASH by strong beam focusing with the aid of a spherical multilayer mirror. Ion charges up to Xe21+ were observed and investigated as a function of irradiance. Our surprising results are discussed in terms of a perturbative and nonperturbative description.

  8. [Advances in neonatal intensive medicine].

    Science.gov (United States)

    Pérez-González, J; Olivares, J L; Ventura, P; Fabre, E

    1983-09-01

    In the last few year a significative reduction on the rates of neonatal morbimortality have appeared. This has been achieved because a better understanding of embrio-fetal physiology, emerged under the patronage of technological development: new diagnostic techniques, monitorization (physiological and therapeutical) in both, pre and postnatal periods. This model of attendance (perinatology) has its' climax in neonatal intensive care. New scientific plans have to be examined continuously in a critical way, according with ethical reasons related with this type of medical assistance.

  9. Low-energy cosmic ray protons from nuclear interactions of cosmic rays with the interstellar medium.

    Science.gov (United States)

    Wang, H. T.

    1973-01-01

    The intensity of low-energy (less than 100 MeV) protons from nuclear interactions of higher-energy (above 100 MeV) cosmic rays with the interstellar medium is calculated. The resultant intensity in the 10- to 100-MeV range is larger by a factor of 3-5 than the observed proton intensity near earth. The calculated intensity from nuclear interactions constitutes a lower limit on the actual proton intensity in interstellar space.

  10. Playful Interaction

    DEFF Research Database (Denmark)

    2003-01-01

    The video Playful Interaction describes a future architectural office, and envisions ideas and concepts for playful interactions between people, materials and appliances in a pervasive and augmented working environment. The video both describes existing developments, technologies and designs...... as well as ideas not yet implemented such as playful modes of interaction with an augmented ball. Playful Interaction has been used as a hybrid of a vision video and a video prototype (1). Externally the video has been used to visualising our new ideas, and internally the video has also worked to inspire...

  11. Underwater Acoustic Propagation in the Philippine Sea: Intensity Fluctuations

    Science.gov (United States)

    White, Andrew W.

    In the spring of 2009, broadband transmissions from a ship-suspended source with a 284 Hz center frequency were received on a moored and navigated vertical array of hydrophones over a range of 107 km in the Philippine Sea. During a 60-hour period over 19 000 transmissions were carried out. The observed wavefront arrival structure reveals four distinct purely refracted acoustic paths: one with a single upper turning point near 80 m depth, two with a pair of upper turning points at a depth of roughly 300 m, and one with three upper turning points at 420 m. Individual path intensity, defined as the absolute square of the center frequency Fourier component for that arrival, was estimated over the 60-hour duration and used to compute scintillation index and log-intensity variance. Monte Carlo parabolic equation simulations using internal-wave induced sound speed perturbations obeying the Garrett-Munk internal-wave en- ergy spectrum were in agreement with measured data for the three deeper-turning paths but differed by as much as a factor of four for the near surface-interacting path. Estimates of the power spectral density and temporal autocorrelation function of intensity were attempted, but were complicated by gaps in the measured time-series. Deep fades in intensity were observed in the near surface-interacting path. Hypothesized causes for the deep fades were examined through further acoustic propagation modeling and analysis of various available oceanographic measurements.

  12. Blood Pulsation Intensity Video Mapping

    CERN Document Server

    Borges, Pedro Henrique de M

    2016-01-01

    In this study, we make non-invasive, remote, passive measurements of the heart beat frequency and determine the map of blood pulsation intensity in a region of interest (ROI) of skin. The ROI used was the forearm of a volunteer. The method employs a regular video camera and visible light, and the video acquisition takes less than 1 minute. The mean cardiac frequency found in our volunteer was within 1 bpm of the ground-truth value simultaneously obtained via earlobe plethysmography. Using the signals extracted from the video images, we have determined an intensity map for the blood pulsation at the surface of the skin. In this paper we present the experimental and data processing details of the work and well as limitations of the technique. ----------------------------------------- Neste estudo medimos a frequ\\^encia card\\'iaca de forma n\\~ao invasiva, remota e passiva e determinamos o mapa da atividade de pulsa\\c{c}\\~ao sangu\\'inea numa regi\\~ao de interesse (ROI) da pele. A ROI utilizada foi o antebra\\c{c}o...

  13. Ionization Induced Scattering of Femtosecond Intense Laser Pulses in Cluster Plasmas

    Institute of Scientific and Technical Information of China (English)

    Wang Xiangxin; Wang Cheng; Liu Jiansheng; Li Shaohui; Ni Guoquan

    2005-01-01

    The 45° scattering of a femtosecond (60 fs) intense laser pulse with a 20 nm FWHM (the full width at half maximum) spectrum centered at 790 nm has been studied experimentally while focused in argon clusters at intensity ~ 1016 W/cra2. Scattering spectra under different backing pressures and laser-plasma interaction lengths were obtained, which showed spectral blueshifting, beam refraction and complex modulation. These ionization-induced effects reveal the modulation of laser pulses propagating in plasmas and the existing obstacle in laser cluster interaction at high laser intensity and high electron density.

  14. Aesthetic interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Iversen, Ole Sejer; Krogh, Peter;

    2004-01-01

    There is a growing interest in considering aesthetic aspects in the design of interactive systems. A set of approaches are emerging each representing different applications of the terminology as well as different inherent assumptions on the role of the user, designer and interaction ideals....... In this paper, we use the concept of Pragmatist Aesthetics to provide a framework for distinguishing between different approaches to aesthetics. Moreover, we use our own design cases to illustrate how pragmatist aesthetics is a promising path to follow in the context of designing interactive systems......, as it promotes aesthetics of use, rather than aesthetics of appearance. We coin this approach in the perspective of aesthetic interaction. Finally we make the point that aesthetics is not re-defining everything known about interactive systems. We provide a framework placing this perspective among other...

  15. Laser-driven generation of ultra-intense proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Badziak, J.; Jablonski, S.; Kubkowska, M.; Parys, P.; Rosinski, M.; Wolowski, J. [EURATOM, Inst Plasma Phys and Laser Microfus, PL-00908 Warsaw (Poland); Antici, P.; Fuchs, J.; Mancic, A. [UPMC, LULI, Ecole Polytech, CNRS, CEA, F-91128 Palaiseau (France); Szydlowski, A. [Andrzej Soltan Inst Nucl Studies, Otwock (Poland)

    2010-07-01

    The results of experimental and numerical studies of high-intensity proton beam generation driven by a short laser pulse of relativistic intensity are reported. In the experiment, a 350 fs laser pulse of 1.06 or 0.53 m wavelength and intensity up to 2*10{sup 19} Wcm{sup -2} irradiated a thin (0.6-2{mu}m) plastic (PS) or Au/PS (plastic covered by 0.2{mu}m Au front layer) target along the target normal. The effect of laser intensity, the target structure and the laser wavelength on the proton beam parameters and laser-protons energy conversion efficiency were examined. Both the measurements and one-dimensional particle-in-cell simulations showed that MeV proton beams of intensity 10{sup 18}Wcm{sup -2} and current density 10{sup 12}Acm{sup -2} at the source can be produced when the laser intensity-wavelength squared product I{sub L{lambda}}{sup 2} is 10{sup 19}Wcm{sup -2}m{sup 2} and the laser-target interaction conditions approach the skin-layer ponderomotive acceleration (SLPA) requirements. The simulations also proved that at I{sub L{lambda}}{sup 2} {>=} 5*10{sup 19}Wcm{sup -2}m{sup 2} and {lambda} {<=} 0.53{mu}m, SLPA clearly prevails over other acceleration mechanisms and it can produce multi-MeV proton beams of extremely high intensities above 10{sup 20}Wcm{sup -2}. (authors)

  16. Intensive Care for Eclampic Coma

    Directory of Open Access Journals (Sweden)

    V. V. Moroz

    2010-01-01

    Full Text Available Objective: to enhance the efficiency of treatment of puerperas with eclampic coma, by substantiating, developing, and introducing new algorithms for correction of systemic hemodynamic, metabolic disturbances, and perfusion-metabolic changes in brain tissues. Subjects and methods. Studies were conducted in 18 puerperas with eclampic coma (Group 2 in whom the authors used a new treatment algorithm aimed at maintaining baseline cerebral perfusion pressure (CPP, restoring volemic levels at the expense of interstitial fluid. A control group (Group 1 included 30 patients who received conventional standard therapy. Regional cerebral circulation was measured by a non-invasive (inhalation radioisotopic method, by applying the tracer 131Xe, as described by V. D. Obrist et al., on a modified КПРДИ-1 apparatus (USSR. The rate of brain oxygen uptake was determined from the oxygen content between the artery and the internal jugular vein. Central hemodynamic parameters were studied by the direct method of right heart catheterization using a flow-directed Swan-Ganz catheter. The volumes of total and extracellular fluids were estimated using 20% urea and mannitol solutions, respectively, at 0.2 g/kg weight by the procedure of V. M. Mogen. Circulating blood volume (CBV was determined by a radioisotopic method using 131iodine albumin on an УPI-7 apparatus (USSR. Cerebral spinal fluid pressure was measured by an ИиНД apparatus. Studies were made in four steps: 1 on admission; 2 on days 2—3; 3 during emergence from coma; 4 before transition. Results. The use of the new algorithm for intensive care for eclampic coma, which is aimed at improving the perfusion metabolic provision of brain structures, with a reduction in mean blood pressure by 10—15% of the baseline level, by administering magnesium sulfate and nimodipine, and at compensating for CBV by high-molecular-weight hydroxyethylated starch (stabizol, ensured early emergence from a comatose state

  17. A conceptual framework of clinical nursing care in intensive care1

    Science.gov (United States)

    da Silva, Rafael Celestino; Ferreira, Márcia de Assunção; Apostolidis, Thémistoklis; Brandão, Marcos Antônio Gomes

    2015-01-01

    Objective: to propose a conceptual framework for clinical nursing care in intensive care. Method: descriptive and qualitative field research, carried out with 21 nurses from an intensive care unit of a federal public hospital. We conducted semi-structured interviews and thematic and lexical content analysis, supported by Alceste software. Results: the characteristics of clinical intensive care emerge from the specialized knowledge of the interaction, the work context, types of patients and nurses characteristic of the intensive care and care frameworks. Conclusion: the conceptual framework of the clinic's intensive care articulates elements characteristic of the dynamics of this scenario: objective elements regarding technology and attention to equipment and subjective elements related to human interaction, specific of nursing care, countering criticism based on dehumanization. PMID:26487133

  18. Sleep in intensive care unit

    DEFF Research Database (Denmark)

    Boyko, Yuliya; Jennum, Poul; Nikolic, Miki

    2017-01-01

    PURPOSE: To determine if improving intensive care unit (ICU) environment would enhance sleep quality, assessed by polysomnography (PSG), in critically ill mechanically ventilated patients. MATERIALS AND METHODS: Randomized controlled trial, crossover design. The night intervention "quiet routine......" protocol was directed toward improving ICU environment between 10pm and 6am. Noise levels during control and intervention nights were recorded. Patients on mechanical ventilation and able to give consent were eligible for the study. We monitored sleep by PSG.The standard (American Association of Sleep...... Medicine) sleep scoring criteria were insufficient for the assessment of polysomnograms. Modified classification for sleep scoring in critically ill patients, suggested by Watson et al. (Crit Care Med 2013;41:1958-1967), was used. RESULTS: Sound level analysis showed insignificant effect...

  19. HI intensity mapping with FAST

    CERN Document Server

    Bigot-Sazy, Marie-Anne; Battye, Richard A; Browne, Ian W A; Chen, Tianyue; Dickinson, Clive; Harper, Stuart; Maffei, Bruno; Olivari, Lucas C; Wilkinson, Peter N

    2015-01-01

    We discuss the detectability of large-scale HI intensity fluctuations using the FAST telescope. We present forecasts for the accuracy of measuring the Baryonic Acoustic Oscillations and constraining the properties of dark energy. The FAST $19$-beam L-band receivers ($1.05$--$1.45$ GHz) can provide constraints on the matter power spectrum and dark energy equation of state parameters ($w_{0},w_{a}$) that are comparable to the BINGO and CHIME experiments. For one year of integration time we find that the optimal survey area is $6000\\,{\\rm deg}^2$. However, observing with larger frequency coverage at higher redshift ($0.95$--$1.35$ GHz) improves the projected errorbars on the HI power spectrum by more than $2~\\sigma$ confidence level. The combined constraints from FAST, CHIME, BINGO and Planck CMB observations can provide reliable, stringent constraints on the dark energy equation of state.

  20. MR image intensity inhomogeneity correction

    Science.gov (United States)

    (Vişan Pungǎ, Mirela; Moldovanu, Simona; Moraru, Luminita

    2015-01-01

    MR technology is one of the best and most reliable ways of studying the brain. Its main drawback is the so-called intensity inhomogeneity or bias field which impairs the visual inspection and the medical proceedings for diagnosis and strongly affects the quantitative image analysis. Noise is yet another artifact in medical images. In order to accurately and effectively restore the original signal, reference is hereof made to filtering, bias correction and quantitative analysis of correction. In this report, two denoising algorithms are used; (i) Basis rotation fields of experts (BRFoE) and (ii) Anisotropic Diffusion (when Gaussian noise, the Perona-Malik and Tukey's biweight functions and the standard deviation of the noise of the input image are considered).

  1. Beam intensity upgrade at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Marchionni, A.; /Fermilab

    2006-07-01

    The performance of the Fermilab proton accelerator complex is reviewed. The coming into operation of the NuMI neutrino line and the implementation of slip-stacking to increase the anti-proton production rate has pushed the total beam intensity in the Main Injector up to {approx} 3 x 10{sup 13} protons/pulse. A maximum beam power of 270 kW has been delivered on the NuMI target during the first year of operation. A plan is in place to increase it to 350 kW, in parallel with the operation of the Collider program. As more machines of the Fermilab complex become available with the termination of the Collider operation, a set of upgrades are being planned to reach first 700 kW and then 1.2 MW by reducing the Main Injector cycle time and by implementing proton stacking.

  2. Intensive Insulin Therapy: Tight Blood Sugar Control

    Science.gov (United States)

    ... insulin therapy can help you achieve desired blood sugar control and what intensive insulin therapy requires of ... aggressive treatment approach designed to control your blood sugar levels. Intensive insulin therapy requires close monitoring of ...

  3. Human influence on tropical cyclone intensity

    Science.gov (United States)

    Sobel, Adam H.; Camargo, Suzana J.; Hall, Timothy M.; Lee, Chia-Ying; Tippett, Michael K.; Wing, Allison A.

    2016-07-01

    Recent assessments agree that tropical cyclone intensity should increase as the climate warms. Less agreement exists on the detection of recent historical trends in tropical cyclone intensity. We interpret future and recent historical trends by using the theory of potential intensity, which predicts the maximum intensity achievable by a tropical cyclone in a given local environment. Although greenhouse gas-driven warming increases potential intensity, climate model simulations suggest that aerosol cooling has largely canceled that effect over the historical record. Large natural variability complicates analysis of trends, as do poleward shifts in the latitude of maximum intensity. In the absence of strong reductions in greenhouse gas emissions, future greenhouse gas forcing of potential intensity will increasingly dominate over aerosol forcing, leading to substantially larger increases in tropical cyclone intensities.

  4. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2012-01-01

    Ready to create rich interactive experiences with your artwork, designs, or prototypes? This is the ideal place to start. With this hands-on guide, you'll explore several themes in interactive art and design-including 3D graphics, sound, physical interaction, computer vision, and geolocation-and learn the basic programming and electronics concepts you need to implement them. No previous experience is necessary. You'll get a complete introduction to three free tools created specifically for artists and designers: the Processing programming language, the Arduino microcontroller, and the openFr

  5. Pondermotive absorption of a short intense laser pulse in a non-uniform plasma

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, A.A.; Platonov, K.Yu. [Inst. for Laser Physics, SC `Vavilov State Optical Inst.` 12, Birzhevaya line, St Petersburg (Russian Federation); Tanaka, K.A.

    1998-03-01

    An analytical description of the pondermotive absorption mechanism at a short high intense laser pulse interaction with a strong inhomogeneous plasma is presented. The optimal conditions for the maximum of resonance absorption of laser pulse interaction with non-uniform plasma at normal incidence are founded. (author)

  6. Effects of extensive system versus semi-intensive and intensive systems on growth and carcass quality of dairy kids

    Directory of Open Access Journals (Sweden)

    Pedro Zurita Herrera

    2011-11-01

    Full Text Available The aim of this research was to study the effects of three different management systems on growth and carcass quality of 61 Murciano-Granadina breed kids and their interaction with sex. In the extensive system, 21 kids were allocated to suckle from their dams on free-range pasture with no additional feedstuff. In the semi-intensive system, 20 kids were suckled from their dams and had access to alfalfa hay and cereal straw (no free-range pasture. In the intensive system, 20 kids were separated from the dams at birth and then fed with milk replacer and alfalfa hay. Animals were slaughtered at 7.00 ± 1.00 kg of average BW. The semi-intensive system and extensive system kids grew faster than intensive system animals (127, 113 and 96 g/d, respectively. Differences in energy intake may explain these differences. Intensive system kids displayed the lowest real dressing percentages, calculated as 100 × (hot carcass weight/empty body weight, due to high development of empty gastrointestinal tract. The long leg and carcass were larger in extensive system kids than in kids from other management systems, presumably due to high physical activity on the free-range pastures. The carcasses and cuts from semi-intensive system and extensive system kids displayed more fat than those of intensive system kids. Males grew faster than females (122 and 103 g/d, respectively. Carcasses in male kids showed a higher content of bones but a lower content of fat than carcasses in female kids. The extensive system is feasible for producing kid meat from a dairy breed.

  7. On the Cultivation of Intensive Reading Skills

    Institute of Scientific and Technical Information of China (English)

    杨雪琴

    2008-01-01

    This paper concerns the importance of the cultivation of reading skills,the characteristics of intensive reading and how to cultivate the intensive reading skills.Since the focus of this papre is how to cultivate the intensive reading skills,we make a systematic exposition from three points: word study,grammar patterns and text.

  8. Treatment Intensity and Childhood Apraxia of Speech

    Science.gov (United States)

    Namasivayam, Aravind K.; Pukonen, Margit; Goshulak, Debra; Hard, Jennifer; Rudzicz, Frank; Rietveld, Toni; Maassen, Ben; Kroll, Robert; van Lieshout, Pascal

    2015-01-01

    Background: Intensive treatment has been repeatedly recommended for the treatment of speech deficits in childhood apraxia of speech (CAS). However, differences in treatment outcomes as a function of treatment intensity have not been systematically studied in this population. Aim: To investigate the effects of treatment intensity on outcome…

  9. Subjective intensity and pleasantness in taste

    NARCIS (Netherlands)

    Veldhuizen, M.G.

    2006-01-01

    This thesis contains studies on intensity and pleasantness in taste perception. There is a formal relationship between intensity and hedonic value of stimuli, which can be expressed in an inverted U. The fact that pleasantness depends partially on stimulus intensity poses a problem when one wants to

  10. 7 CFR 29.3011 - Color intensity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Color intensity. 29.3011 Section 29.3011 Agriculture... Color intensity. The varying degree of saturation or chroma. Color intensity as applied to tobacco describes the strength or weakness of a specific color or hue. It is applicable to all colors...

  11. 7 CFR 29.1006 - Color intensity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Color intensity. 29.1006 Section 29.1006 Agriculture... Type 92) § 29.1006 Color intensity. The varying degree of saturation or chroma. Color intensity as applied to tobacco describes the strength or weakness of a specific color or hue. (See Elements of...

  12. 7 CFR 29.2508 - Color intensity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Color intensity. 29.2508 Section 29.2508 Agriculture...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2508 Color intensity. The varying degree of saturation or chroma. Color intensity as applied to tobacco describes the strength or weakness of a...

  13. 7 CFR 29.2258 - Color intensity.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Color intensity. 29.2258 Section 29.2258 Agriculture... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2258 Color intensity. The varying degree of saturation or chroma. Color intensity as applied to tobacco describes...

  14. Building collaborative teams in neonatal intensive care.

    Science.gov (United States)

    Brodsky, Dara; Gupta, Munish; Quinn, Mary; Smallcomb, Jane; Mao, Wenyang; Koyama, Nina; May, Virginia; Waldo, Karen; Young, Susan; Pursley, DeWayne M

    2013-05-01

    The complex multidisciplinary nature of neonatal intensive care combined with the numerous hand-offs occurring in this shift-based environment, requires efficient and clear communication and collaboration among staff to provide optimal care. However, the skills required to function as a team are not typically assessed, discussed, or even taught on a regular basis among neonatal personnel. We developed a multidisciplinary, small group, interactive workshop based on Team STEPPS to provide staff with formal teamwork skills, and to introduce new team-based practices; 129 (95%) of the eligible 136 staff were trained. We then compared the results of the pretraining survey (completed by 114 (84%) of staff) with the post-training survey (completed by 104 (81%) of participants) 2 years later. We found an improvement in the overall teamwork score from 7.37 to 8.08 (p=showing that staff had greater job fulfilment (p=<0.0001), believed that their abilities were being utilised properly (p=0.003), and felt more respected (p=0.0037). 90% of staff found the new practice of team meetings to help increase awareness of unit acuity, and 77% of staff noted that they had asked for help or offered assistance because of information shared during these meetings. In addition to summarising the results of our training programme, this paper also provides practical tools that may be of use in developing team training programmes in other neonatal units.

  15. Embarrassing Interactions

    DEFF Research Database (Denmark)

    Deterding, Sebastian; Lucero, Andrés; Holopainen, Jussi;

    2015-01-01

    Wherever the rapid evolution of interactive technologies disrupts standing situational norms, creates new, often unclear situational audiences, or crosses cultural boundaries, embarrassment is likely. This makes embarrassment a fundamental adoption and engagement hurdle, but also a creative design...

  16. Interaction graphs

    DEFF Research Database (Denmark)

    Seiller, Thomas

    2016-01-01

    Interaction graphs were introduced as a general, uniform, construction of dynamic models of linear logic, encompassing all Geometry of Interaction (GoI) constructions introduced so far. This series of work was inspired from Girard's hyperfinite GoI, and develops a quantitative approach that should...... be understood as a dynamic version of weighted relational models. Until now, the interaction graphs framework has been shown to deal with exponentials for the constrained system ELL (Elementary Linear Logic) while keeping its quantitative aspect. Adapting older constructions by Girard, one can clearly define...... "full" exponentials, but at the cost of these quantitative features. We show here that allowing interpretations of proofs to use continuous (yet finite in a measure-theoretic sense) sets of states, as opposed to earlier Interaction Graphs constructions were these sets of states were discrete (and finite...

  17. Neutrino Interactions

    CERN Document Server

    McFarland, Kevin

    2008-01-01

    This manuscript summarizes a series of three lectures on interactions of neutrinos . The lectures begin with a pedagogical foundation and then explore topics of interest to current and future neutrino oscillation and cross-section experiments.

  18. Interactive Workspaces

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst

    augmented reality, interactive building elements, and mobile devices to support new ways of working in a diversity of application domains with work situations ranging from individual work, through local collaboration, to distributed collaboration. The work situations may take place in offices/project rooms...... or in the field. The types of tasks may range from adhoc to more planned forms of interaction. We involve users from specific application domains and use settings continuously in our research following a participatory design approach....

  19. Emotional Intensity Modulates the Integration of Bimodal Angry Expressions: ERP Evidence

    Directory of Open Access Journals (Sweden)

    Zhihui Pan

    2017-06-01

    Full Text Available Integration of information from face and voice plays a central role in social interactions. The present study investigated the modulation of emotional intensity on the integration of facial-vocal emotional cues by recording EEG for participants while they were performing emotion identification task on facial, vocal, and bimodal angry expressions varying in emotional intensity. Behavioral results showed the rates of anger and reaction speed increased as emotional intensity across modalities. Critically, the P2 amplitudes were larger for bimodal expressions than for the sum of facial and vocal expressions for low emotional intensity stimuli, but not for middle and high emotional intensity stimuli. These findings suggested that emotional intensity modulates the integration of facial-vocal angry expressions, following the principle of Inverse Effectiveness (IE in multimodal sensory integration.

  20. Classification of knowledge-intensive organizations

    Science.gov (United States)

    Marquart, Edward J.

    Managing knowledge workers in knowledge-intensive organizations has become important because knowledge itself is emerging as a primary sustainable competitive advantage. This dissertation traces the development of two important items related to knowledge-intensive organizations. First, it documents a careful study of the literature which allows for the construction of a Knowledge-Intensity Continuum. This continuum then forms the basis for the development of a Knowledge-Intensity Assessment survey instrument which allows an organization to be placed along this continuum. A cross-section of research, consulting, and manufacturing organizations was surveyed using this instrument. The findings provided evidence that supports the validity of the Knowledge-Intensity Continuum. Additionally, onsite interviews provided evidence that the Knowledge-Intensity Assessment survey can be used as a tool to locate any organization on this continuum. Using this survey to clearly identify knowledge-intensive organizations will allow for further research into effective management systems for knowledge workers in these organizations.

  1. Spatially Confined Propagation of Intense Ultraviolet Radiation in Plasmas.

    Science.gov (United States)

    Shi, Xiaomei

    X-ray amplification requires a high energy deposition rate in a high aspect-ratio volume. High power lasers for x-ray laser pumping have become available with the development of the short pulse and high intensity laser technology capable of producing pulses with a peak power as high as 10^{12} watts. Short pulses of high intensity x-ray have been observed in laser -plasma interactions, which encurages many scientists actively pursuing the goal of constructing practical x-ray lasers. Our approach has concentrated on producing high aspect ratio x-ray amplifying medium by spatially confined propagation of high power laser pulse in plasmas. A high intensity laser beam induces nonlinear refractive index changes in plasma. In the case of subpicosecond ultrahigh power laser-plasma interaction, the dominant mechanisms responsible for the refractive index change in plasmas are: (1) the relativistic free electron mass increase due to the increase of electron oscillation velocity in the intense electromagnetic field of the laser pulses; and (2) displacement of free electrons out of the high intensity region of the laser beam by ponderomotive force. Both of the above effects lead to a refractive index change of the plasma, which in turn has a positive lensing effect on the beam. If the focusing effect is strong enough to overcome diffraction the beam will stay in a spatially confined mode of propagation. This confined propagation provides an effective method of concentrating energy. The field intensity associated with the confined propagation is so high that the highly excited medium with high aspect ratio suitable for x-ray amplification can be achieved. In this research we have successfully demonstrated spatially confined propagation of 500 GW subpicosecond laser pulse in laser induced plasma. The measured diameter of the propagation is less than 2 μm and the aspect ratio of the confined propagation is over 1000. The filed intensity associated with the propagation is

  2. Interaction Widget

    DEFF Research Database (Denmark)

    Ingstrup, Mads

    2003-01-01

    This pattern describes the idea of making a user interface of discrete, reusable entities---here called interaction widgets. The idea behind widgets is described using two perspectives, that of the user and that of the developer. It is the forces from these two perspectives that are balanced in t...... in the pattern. The intended audience of the pattern is developers and researchers within the field of human computer interaction.......This pattern describes the idea of making a user interface of discrete, reusable entities---here called interaction widgets. The idea behind widgets is described using two perspectives, that of the user and that of the developer. It is the forces from these two perspectives that are balanced...

  3. Hadronic Interactions

    CERN Document Server

    Yamazaki, Takeshi

    2015-01-01

    Understanding hadronic interactions is crucial for investigating the properties of unstable hadrons, since measuring physical quantities for unstable hadrons including the resonance mass and decay width requires simultaneous calculations of final scattering states. Recent studies of hadronic scatterings and decays are reviewed from this point of view. The nuceon-nucleon and multi-nucleon interactions are very important to understand the formation of nucleus from the first principle of QCD. These interactions have been studied mainly by two methods, due originally to L\\"uscher and to HALQCD. The results obtained from the two methods are compared in three channels, $I=2$ two-pion, H-dibaryon, and two-nucleon channels. So far the results from the two methods for the two-nucleon channels are different even at the level of the presence or absence of bound states. We then discuss possible uncertainties in each method. Recent results on the binding energy for helium nuclei are also reviewed.

  4. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy

    Governance has become one of the most commonly used concepts in contemporary political science. It is, however, often used to mean a variety of different things. This book helps to clarify this conceptual muddle by concentrating on one variety of governance-interactive governance. The authors argue...... that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other governments......, but all these forms represent means of governing involving mixtures of state action with the actions of other entities.This book explores thoroughly this meaning of governance, and links it to broader questions of governance. In the process of explicating this dimension of governance the authors also...

  5. The intensity of A. Wat

    Directory of Open Access Journals (Sweden)

    Jerzy Kandziora

    2012-01-01

    Full Text Available The article discusses a collection of literary essays Elementy do portretu. Szkice o twórczości Aleksandra Wata published and edited by Poznań-based specialists in Polish literature and dedicated to Professor Ewa Wiegandt. The starting point for the discussion is the observation that the authors of the essays had to grapple with the elusiveness and multidimensional character of the output of A. Wat, with the entanglement of the text of his works with the text of his biography, and finally with the multitude of its cultural contexts. The reviewer distinguishes four research currents in the collection of essays, each being a different answer to these particular traits of Wat’s writing. Historical and literary studies in the book show the author in his relations and as a non-categorizable author, and challenge the Futurist character of his juvenile writings by juxtaposing them with earlier Symbolism and later Catastrophism. The interpretative study current tries to find ways to define Wat through reading his individual works. Here, the overriding opposition between ”closeness” and ”openness”, so pivotal in the poet’s works, becomes apparent. The current of thematology that present Wat’s literary topoi in relation to his biography is well represented in the volume. Finally, the studies that cross the strictly literary horizon try to capture the multi-tier structures of Wat’s works, reinterpreting them from the sociological, historical or axiological perspectives. The final conclusion of the review is the acknowledgement of the richness offered by the book that corresponds well to the intensity of works and the biography of the author.

  6. Interactive benchmarking

    DEFF Research Database (Denmark)

    Lawson, Lartey; Nielsen, Kurt

    2005-01-01

    distance functions. The frontier is given by an explicit quantile, e.g. “the best 90 %”. Using the explanatory model of the inefficiency, the user can adjust the frontiers by submitting state variables that influence the inefficiency. An efficiency study of Danish dairy farms is implemented......We discuss individual learning by interactive benchmarking using stochastic frontier models. The interactions allow the user to tailor the performance evaluation to preferences and explore alternative improvement strategies by selecting and searching the different frontiers using directional...... in the suggested benchmarking tool. The study investigates how different characteristics on dairy farms influences the technical efficiency....

  7. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2009-01-01

    Make cool stuff. If you're a designer or artist without a lot of programming experience, this book will teach you to work with 2D and 3D graphics, sound, physical interaction, and electronic circuitry to create all sorts of interesting and compelling experiences -- online and off. Programming Interactivity explains programming and electrical engineering basics, and introduces three freely available tools created specifically for artists and designers: Processing, a Java-based programming language and environment for building projects on the desktop, Web, or mobile phonesArduino, a system t

  8. Collocated Interaction

    DEFF Research Database (Denmark)

    E. Fischer, Joel; Porcheron, Martin; Lucero, Andrés

    2016-01-01

    In the 25 years since Ellis, Gibbs, and Rein proposed the time-space taxonomy, research in the ‘same time, same place’ quadrant has diversified, perhaps even fragmented. This one-day workshop will bring together researchers with diverse, yet convergent interests in tabletop, surface, mobile......, and wearable technologies, spaces and spatial interaction, and those interested in the social aspects of interaction, such as conversation analysis and ethnomethodology. These communities have matured considerably, and produced significant exemplars of systems, methods, and studies concerned with collocated...

  9. Kinesthetic Interaction

    DEFF Research Database (Denmark)

    Fogtmann, Maiken Hillerup; Fritsch, Jonas; Kortbek, Karen Johanne

    2008-01-01

    Within the Human-Computer Interaction community there is a growing interest in designing for the whole body in interaction design. The attempts aimed at addressing the body have very different outcomes spanning from theoretical arguments for understanding the body in the design process, to more...... to reveal bodily potential in relation to three design themes – kinesthetic development, kinesthetic means and kinesthetic disorder; and seven design parameters – engagement, sociality, movability, explicit motivation, implicit motivation, expressive meaning and kinesthetic empathy. The framework is a tool...

  10. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy

    that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other governments...... explore some of the more fundamental questions about governance theory. For example, although governance is talked about a great deal political science has done relatively little about how to measure this concept. Likewise, the term multi-level governance has become widely used but its important...

  11. Intense-field many-body S-matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Becker, A [Max-Planck-Institut fuer Physik komplexer Systeme, Noethnitzer Str 38, D-01187 Dresden (Germany); Faisal, F H M [Fakultaet fuer Physik, Universitaet Bielefeld, Postfach 100131, D-33501 Bielefeld (Germany)

    2005-02-14

    Intense-field many-body S-matrix theory (IMST) provides a systematic ab initio approach to investigate the dynamics of atoms and molecules interacting with intense laser radiation. We review the derivation of IMST as well as its diagrammatic representation and point out its advantage over the conventional 'prior' and 'post' expansions which are shown to be special cases of IMST. The practicality and usefulness of the theory is illustrated by its application to a number of current problems of atomic and molecular ionization in intense fields. We also present a consistent S-matrix formulation of the quantum amplitude for high harmonic generation (HHG) and point out some of the most general properties of HHG radiation emitted by a single atom as well as its relation to coherent emission from many atoms. Experimental results for single and double (multiple) ionization of atoms and the observed distributions of coincidence measurements are analysed and the dominant mechanisms behind them are discussed. Ionization of more complex systems such as diatomic and polyatomic molecules in intense laser fields is analysed as well using IMST and the results are discussed with special attention to the role of molecular orbital symmetry and molecular orientation in space. The review ends with a summary and a brief outlook. (topical review)

  12. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, M.K.; Shamoun, B.I.; Bonazza, R.; Corradini, M.L. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics

    1998-01-01

    Stratified Fuel-Coolant Interaction (FCI) experiments with Refrigerant-134a and water were performed in a large-scale system. Air was uniformly injected into the coolant pool to establish a pre-existing void which could suppress the explosion. Two competing effects due to the variation of the air flow rate seem to influence the intensity of the explosion in this geometrical configuration. At low flow rates, although the injected air increases the void fraction, the concurrent agitation and mixing increases the intensity of the interaction. At higher flow rates, the increase in void fraction tends to attenuate the propagated pressure wave generated by the explosion. Experimental results show a complete suppression of the vapor explosion at high rates of air injection, corresponding to an average void fraction of larger than 30%. (author)

  13. Interactive Storytelling

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions, an...

  14. Interactive Astronomy.

    Science.gov (United States)

    Martin, Jean K.

    1997-01-01

    Presents guiding principles for developing interactive lessons for the World Wide Web. Describes "Amazing Space: Education Online from the Hubble Space Telescope", a program where students study spectacular Hubble Space Telescope images of stars and star-forming regions to learn about the life cycle of stars and the creation of atoms. (JRH)

  15. Interactive Storytelling

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions...

  16. CAS course on Intensity Limitations in Particle Beams at CERN

    CERN Multimedia

    CERN Accelerator School

    2015-01-01

    The CERN Accelerator School (CAS) recently organised a specialised course on Intensity Limitations in Particle Beams, at CERN from 2 to 11 November, 2015.     Many accelerators and storage rings, whether intended for particle physics experiments, synchrotron light sources or industrial applications, require beams of high brightness and the highest possible intensities. A good understanding of the possible limitations is required to achieve the desired performance. This course covered the interaction of beams with their surroundings and with other beams, as well as further collective effects. The lectures on the effects and possible mitigations were complemented by tutorials. The course was very successful, with 66 students representing 14 nationalities attending. Most participants came from European counties, but also from Armenia, China and Russia. Feedback from the participants was positive, reflecting the standard of the lectures and teaching. In addition to the academic pro...

  17. Intensity modulated short circuit current spectroscopy for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kavasoglu, Nese; Sertap Kavasoglu, A.; Birgi, Ozcan; Oktik, Sener [Mugla University, Faculty of Arts and Sciences, Physics Department, TR-48000 Mugla (Turkey); Mugla University Clean Energy Research and Development Centre, TR-48000 Mugla (Turkey)

    2011-02-15

    Understanding charge separation and transport is momentously important for the rectification of solar cell performance. To probe photo-generated carrier dynamics, we implemented intensity modulated short circuit current spectroscopy (IMSCCS) on porous Si and Cu(In{sub x},Ga{sub 1-x})Se{sub 2} solar cells. In this experiment, the solar cells were lightened with sinusoidally modulated monochromatic light. The photocurrent response of the solar cell as a function of modulation frequency is measured as the optoelectronic transfer function of the system. The optoelectronic transfer function introduces the connection between the modulated light intensity and measured AC current of the solar cell. In this study, interaction of free carriers with the density of states of the porous Si and Cu(In{sub x}, Ga{sub 1-x})Se{sub 2} solar cells was studied on the basis of charge transport time by IMSCCS data. (author)

  18. Raman forward scattering of high-intensity chirped laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, C.B.; Esarey, E.; Shadwick, B.A.; Leemans, W.P.

    2002-06-23

    Raman forward scattering of a high-intensity, short-duration, frequency-chirped laser pulse propagating in an underdense plasma is examined. The growth of the direct forward scattered light is calculated for a laser pulse with a linear frequency chirp in various spatio-temporal regimes. This includes a previously undescribed regime of strongly-coupled four-wave nonresonant interaction, which is important for relativistic laser intensities. In all regimes of forward scattering, it is shown that the growth rate increases (decreases) for positive (negative) frequency chirp. The effect of chirp on the growth rate is relatively minor, i.e., a few percent chirp yields few percent changes in the growth rates. Relation of these results to recent experiments is discussed.

  19. Limiting current of intense electron beams in a decelerating gap

    Science.gov (United States)

    Nusinovich, G. S.; Beaudoin, B. L.; Thompson, C.; Karakkad, J. A.; Antonsen, T. M.

    2016-02-01

    For numerous applications, it is desirable to develop electron beam driven efficient sources of electromagnetic radiation that are capable of producing the required power at beam voltages as low as possible. This trend is limited by space charge effects that cause the reduction of electron kinetic energy and can lead to electron reflection. So far, this effect was analyzed for intense beams propagating in uniform metallic pipes. In the present study, the limiting currents of intense electron beams are analyzed for the case of beam propagation in the tubes with gaps. A general treatment is illustrated by an example evaluating the limiting current in a high-power, tunable 1-10 MHz inductive output tube (IOT), which is currently under development for ionospheric modification. Results of the analytical theory are compared to results of numerical simulations. The results obtained allow one to estimate the interaction efficiency of IOTs.

  20. INTENSIVE READING:PROBLEMS AND OPPORTUNITIES

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Intensive reading has once come under attack in Mr.Ian Cotton’s article(Cotton,1990).He arguesthat intensive reading contributes nothing to the development of English language teaching andlearning in China.Although,as a teacher of intensive reading(IR),I disagree with some of hisconclusions,I think that he makes many relevant remarks about the drawbacks in the teaching ofintensive reading.

  1. Experiencing intensive care: women's voices in Jordan

    OpenAIRE

    Zeilani, Ruqayya Sayed Ali

    2008-01-01

    This study explores women's experiences of critical illness in Jordanian intensive care units. A narrative approach was employed to access Jordanian women's stories of their critical illness and to study how these accounts changed during the period following their discharge from intensive care. The study was conducted in two hospitals in a major Jordanian city. A purposive sample of 16 women who had spent at least 48 hours in intensive care was recruited over a period of six months, with each...

  2. Potential Intake Of Intense Sweeteners In Brazil.

    OpenAIRE

    Toledo, M C; Ioshi, S H

    2015-01-01

    A survey of intense sweetener intakes was carried out in the winter of 1990 and summer of 1991 in Brazil. Data on the potential intake of the intense sweeteners aspartame, cyclamate and saccharin were generated, based on a representative sample of 673 individuals who completed a questionnaire designed to collect information on demographic details and habitual usage of sweetener-containing food and drinks. The respondents were randomly chosen among intense sweetener consumers living the cities...

  3. Average Light Intensity Inside a Photobioreactor

    Directory of Open Access Journals (Sweden)

    Herby Jean

    2011-01-01

    Full Text Available For energy production, microalgae are one of the few alternatives with high potential. Similar to plants, algae require energy acquired from light sources to grow. This project uses calculus to determine the light intensity inside of a photobioreactor filled with algae. Under preset conditions along with estimated values, we applied Lambert-Beer's law to formulate an equation to calculate how much light intensity escapes a photobioreactor and determine the average light intensity that was present inside the reactor.

  4. High Intensity Secondary Beams Driven by Protons

    CERN Document Server

    Galambos, John; Nagaitsev, Sergei

    2013-01-01

    As part of the Intensity Frontier effort within the 2013 Community Summer Study, a workshop on the proton machine capabilities was held (High Intensity Secondary Beams Driven by Proton Beams) April 17-20, 2013 at Brookhaven National Laboratory in Upton, NY. Primary aims of the workshop were to understand: 1) the beam requirements for proposed high intensity proton beam based measurements; 2) the capabilities of existing world-wide high power proton machines; 3) proton facility upgrade plans and proposals for new facilities; 4) and to document the R&D needs for proton accelerators and target systems needed to support proposed intensity frontier measurements. These questions are addressed in this summary.

  5. [Concept for a department of intensive care].

    Science.gov (United States)

    Nierhaus, A; de Heer, G; Kluge, S

    2014-10-01

    Demographic change and increasing complexity are among the reasons for high-tech critical care playing a major and increasing role in today's hospitals. At the same time, intensive care is one of the most cost-intensive departments in the hospital. To guarantee high-quality care, close cooperation of specialised intensive care staff with specialists of all other medical areas is essential. A network of the intensive care units within the hospital may lead to synergistic effects concerning quality of care, simultaneously optimizing the use of human and technical resources. Notwithstanding any organisational concepts, development and maintenance of the highest possible quality of care should be of overriding importance.

  6. The effect of chirped intense femtosecond laser pulses on the Argon cluster

    CERN Document Server

    Ghaforyan, H; Irani, E

    2016-01-01

    The interaction of intense femtosecond laser pulses with atomic Argon clusters has been investigated by using nano-plasma model. Based on the dynamic simulations, ionization process, heating and expansion of a cluster after irradiation by femtosecond laser pulses at intensities up to 2*1017 Wcm-2 are studied. The analytical calculation provides ionization ratefor different mechanisms and time evolution of the density of electrons for different pulse shapes. In this approach the strong dependence of laser intensity, pulse duration and laser shape on the electron energy, the electron density and the cluster size are presented using the intense chirped laser pulses. Based on the presented theoretical modifications, the effect of chirped laser pulse on the complex dynamical process of the interaction is studied. It is found that the energy of electrons and the radius of cluster for the negatively chirped pulsesare improved up to 20% in comparison to the unchirped and positively chirped pulses.

  7. The Effect of Chirped Intense Femtosecond Laser Pulses on the Argon Cluster

    Directory of Open Access Journals (Sweden)

    H. Ghaforyan

    2016-01-01

    Full Text Available The interaction of intense femtosecond laser pulses with atomic Argon clusters has been investigated by using nanoplasma model. Based on the dynamic simulations, ionization process, heating, and expansion of a cluster after irradiation by femtosecond laser pulses at intensities up to 2 × 1017 Wcm−2 are studied. The analytical calculation provides ionization rate for different mechanisms and time evolution of the density of electrons for different pulse shapes. In this approach, the strong dependence of laser intensity, pulse duration, and laser shape on the electron energy, the electron density, and the cluster size is presented using the intense chirped laser pulses. Based on the presented theoretical modifications, the effect of chirped laser pulse on the complex dynamical process of the interaction is studied. It is found that the energy of electrons and the radius of cluster for the negatively chirped pulses are improved up to 20% in comparison to the unchirped and positively chirped pulses.

  8. Laser-intensity effect on beta decay of the free neutron

    Science.gov (United States)

    Rashid, Shahid

    2012-06-01

    Using the exact solution of the minimally coupled Dirac equation as the state for the lepton, the cross section for the weak interaction is calculated in the presence of an intense laser field. A completely new term is discovered due to the interaction of the spin of the electron with the intense laser field present. Moreover, the presence of the dressed lepton only in the initial or final state gives rise to new arguments for the Bessel functions which is different from those calculated by previous authors. We have computed the decay rate of a free neutron in the presence of an intense laser field. It is shown that with the increasing intensity, the lifetime of the free neutron increases nonlinearly.

  9. Rainwater runoff retention on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2013-09-01

    Urban areas are characterised by large proportions of impervious surfaces which increases rainwater runoff and the potential for surface water flooding. Increased precipitation is predicted under current climate change projections, which will put further pressure on urban populations and infrastructure. Roof greening can be used within flood mitigation schemes to restore the urban hydrological balance of cities. Intensive green roofs, with their deeper substrates and higher plant biomass, are able to retain greater quantities of runoff, and there is a need for more studies on this less common type of green roof which also investigate the effect of factors such as age and vegetation composition. Runoff quantities from an aged intensive green roof in Manchester, UK, were analysed for 69 rainfall events, and compared to those on an adjacent paved roof. Average retention was 65.7% on the green roof and 33.6% on the bare roof. A comprehensive soil classification revealed the substrate, a mineral soil, to be in good general condition and also high in organic matter content which can increase the water holding capacity of soils. Large variation in the retention data made the use of predictive regression models unfeasible. This variation arose from complex interactions between Antecedant Dry Weather Period (ADWP), season, monthly weather trends, and rainfall duration, quantity and peak intensity. However, significantly lower retention was seen for high rainfall events, and in autumn, which had above average rainfall. The study period only covers one unusually wet year, so a longer study may uncover relationships to factors which can be applied to intensive roofs elsewhere. Annual rainfall retention for Manchester city centre could be increased by 2.3% by a 10% increase in intensive green roof construction. The results of this study will be of particular interest to practitioners implementing greenspace adaptation in temperate and cool maritime climates.

  10. Management intensity and topography determined plant diversity in vineyards.

    Directory of Open Access Journals (Sweden)

    Juri Nascimbene

    Full Text Available Vineyards are amongst the most intensive forms of agriculture often resulting in simplified landscapes where semi-natural vegetation is restricted to small scattered patches. However, a tendency toward a more sustainable management is stimulating research on biodiversity in these poorly investigated agro-ecosystems. The main aim of this study was to test the effect on plant diversity of management intensity and topography in vineyards located in a homogenous intensive hilly landscape. Specifically, this study evaluated the role of slope, mowing and herbicide treatments frequency, and nitrogen supply in shaping plant diversity and composition of life-history traits. The study was carried out in 25 vineyards located in the area of the Conegliano-Valdobbiadene DOCG (Veneto, NE Italy. In each vineyard, 10 plots were placed and the abundance of all vascular plants was recorded in each plot. Linear multiple regression was used to test the effect of management and topography on plant diversity. Management intensity and topography were both relevant drivers of plant species diversity patterns in our vineyards. The two most important factors were slope and mowing frequency that respectively yielded positive and negative effects on plant diversity. A significant interaction between these two factors was also demonstrated, warning against the detrimental effects of increasing mowing intensity on steep slope where plant communities are more diverse. The response of plant communities to mowing frequency is mediated by a process of selection of resistant growth forms, such in the case of rosulate and reptant species. The other two management-related factors tested in this study, number of herbicide treatments and N fertilization, were less influential. In general, our study corroborates the idea that some simple changes in farming activities, which are compatible with grape production, should be encouraged for improving the natural and cultural value of the

  11. Management intensity and topography determined plant diversity in vineyards.

    Science.gov (United States)

    Nascimbene, Juri; Marini, Lorenzo; Ivan, Diego; Zottini, Michela

    2013-01-01

    Vineyards are amongst the most intensive forms of agriculture often resulting in simplified landscapes where semi-natural vegetation is restricted to small scattered patches. However, a tendency toward a more sustainable management is stimulating research on biodiversity in these poorly investigated agro-ecosystems. The main aim of this study was to test the effect on plant diversity of management intensity and topography in vineyards located in a homogenous intensive hilly landscape. Specifically, this study evaluated the role of slope, mowing and herbicide treatments frequency, and nitrogen supply in shaping plant diversity and composition of life-history traits. The study was carried out in 25 vineyards located in the area of the Conegliano-Valdobbiadene DOCG (Veneto, NE Italy). In each vineyard, 10 plots were placed and the abundance of all vascular plants was recorded in each plot. Linear multiple regression was used to test the effect of management and topography on plant diversity. Management intensity and topography were both relevant drivers of plant species diversity patterns in our vineyards. The two most important factors were slope and mowing frequency that respectively yielded positive and negative effects on plant diversity. A significant interaction between these two factors was also demonstrated, warning against the detrimental effects of increasing mowing intensity on steep slope where plant communities are more diverse. The response of plant communities to mowing frequency is mediated by a process of selection of resistant growth forms, such in the case of rosulate and reptant species. The other two management-related factors tested in this study, number of herbicide treatments and N fertilization, were less influential. In general, our study corroborates the idea that some simple changes in farming activities, which are compatible with grape production, should be encouraged for improving the natural and cultural value of the landscape by

  12. Light induced modulation instability of surfaces under intense illumination

    KAUST Repository

    Burlakov, V. M.

    2013-12-17

    We show that a flat surface of a polymer in rubber state illuminated with intense electromagnetic radiation is unstable with respect to periodic modulation. Initial periodic perturbation is amplified due to periodic thermal expansion of the material heated by radiation. Periodic heating is due to focusing-defocusing effects caused by the initial surface modulation. The surface modulation has a period longer than the excitation wavelength and does not require coherent light source. Therefore, it is not related to the well-known laser induced periodic structures on polymer surfaces but may contribute to their formation and to other phenomena of light-matter interaction.

  13. Metadevice for intensity modulation with sub-wavelength spatial resolution

    CERN Document Server

    Cencillo-Abad, Pablo; Plum, Eric

    2016-01-01

    Effectively continuous control over propagation of a beam of light requires light modulation with pixelation that is smaller than the optical wavelength. Here we propose a spatial intensity modulator with sub-wavelength resolution in one dimension. The metadevice combines recent advances in reconfigurable nanomembrane metamaterials and coherent all-optical control of metasurfaces. It uses nanomechanical actuation of metasurface absorber strips placed near a mirror in order to control their interaction with light from perfect absorption to negligible loss, promising a path towards dynamic beam diffraction, light focusing and holography without unwanted diffraction artefacts.

  14. Data-intensive computing on numerically-insensitive supercomputers

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, James P [Los Alamos National Laboratory; Fasel, Patricia K [Los Alamos National Laboratory; Habib, Salman [Los Alamos National Laboratory; Heitmann, Katrin [Los Alamos National Laboratory; Lo, Li - Ta [Los Alamos National Laboratory; Patchett, John M [Los Alamos National Laboratory; Williams, Sean J [Los Alamos National Laboratory; Woodring, Jonathan L [Los Alamos National Laboratory; Wu, Joshua [Los Alamos National Laboratory; Hsu, Chung - Hsing [ONL

    2010-12-03

    With the advent of the era of petascale supercomputing, via the delivery of the Roadrunner supercomputing platform at Los Alamos National Laboratory, there is a pressing need to address the problem of visualizing massive petascale-sized results. In this presentation, I discuss progress on a number of approaches including in-situ analysis, multi-resolution out-of-core streaming and interactive rendering on the supercomputing platform. These approaches are placed in context by the emerging area of data-intensive supercomputing.

  15. Fundamental Physics at the Intensity Frontier

    CERN Document Server

    Hewett, J.L.; Brock, R.; Butler, J.N.; Casey, B.C.K.; Collar, J.; de Gouvea, A.; Essig, R.; Grossman, Y.; Haxton, W.; Jaros, J.A.; Jung, C.K.; Lu, Z.T.; Pitts, K.; Ligeti, Z.; Patterson, J.R.; Ramsey-Musolf, M.; Ritchie, J.L.; Roodman, A.; Scholberg, K.; Wagner, C.E.M.; Zeller, G.P.; Aefsky, S.; Afanasev, A.; Agashe, K.; Albright, C.; Alonso, J.; Ankenbrandt, C.; Aoki, M.; Arguelles, C.A.; Arkani-Hamed, N.; Armendariz, J.R.; Armendariz-Picon, C.; Arrieta Diaz, E.; Asaadi, J.; Asner, D.M.; Babu, K.S.; Bailey, K.; Baker, O.; Balantekin, B.; Baller, B.; Bass, M.; Batell, B.; Beacham, J.; Behr, J.; Berger, N.; Bergevin, M.; Berman, E.; Bernstein, R.; Bevan, A.J.; Bishai, M.; Blanke, M.; Blessing, S.; Blondel, A.; Blum, T.; Bock, G.; Bodek, A.; Bonvicini, G.; Bossi, F.; Boyce, J.; Breedon, R.; Breidenbach, M.; Brice, S.J.; Briere, R.A.; Brodsky, S.; Bromberg, C.; Bross, A.; Browder, T.E.; Bryman, D.A.; Buckley, M.; Burnstein, R.; Caden, E.; Campana, P.; Carlini, R.; Carosi, G.; Castromonte, C.; Cenci, R.; Chakaberia, I.; Chen, Mu-Chun; Cheng, C.H.; Choudhary, B.; Christ, N.H.; Christensen, E.; Christy, M.E.; Chupp, T.E.; Church, E.; Cline, D.B.; Coan, T.E.; Coloma, P.; Comfort, J.; Coney, L.; Cooper, J.; Cooper, R.J.; Cowan, R.; Cowen, D.F.; Cronin-Hennessy, D.; Datta, A.; Davies, G.S.; Demarteau, M.; DeMille, D.P.; Denig, A.; Dermisek, R.; Deshpande, A.; Dewey, M.S.; Dharmapalan, R.; Dhooghe, J.; Dietrich, M.R.; Diwan, M.; Djurcic, Z.; Dobbs, S.; Duraisamy, M.; Dutta, B.; Duyang, H.; Dwyer, D.A.; Eads, M.; Echenard, B.; Elliott, S.R.; Escobar, C.; Fajans, J.; Farooq, S.; Faroughy, C.; Fast, J.E.; Feinberg, B.; Felde, J.; Feldman, G.; Fierlinger, P.; Fileviez Perez, P.; Filippone, B.; Fisher, P.; Flemming, B.T.; Flood, K.T.; Forty, R.; Frank, M.J.; Freyberger, A.; Friedland, A.; Gandhi, R.; Ganezer, K.S.; Garcia, A.; Garcia, F.G.; Gardner, S.; Garrison, L.; Gasparian, A.; Geer, S.; Gehman, V.M.; Gershon, T.; Gilchriese, M.; Ginsberg, C.; Gogoladze, I.; Gonderinger, M.; Goodman, M.; Gould, H.; Graham, M.; Graham, P.W.; Gran, R.; Grange, J.; Gratta, G.; Green, J.P.; Greenlee, H.; Group, R.C.; Guardincerri, E.; Gudkov, V.; Guenette, R.; Haas, A.; Hahn, A.; Han, T.; Handler, T.; Hardy, J.C.; Harnik, R.; Harris, D.A.; Harris, F.A.; Harris, P.G.; Hartnett, J.; He, B.; Heckel, B.R.; Heeger, K.M.; Henderson, S.; Hertzog, D.; Hill, R.; Hinds, E.A.; Hitlin, D.G.; Holt, R.J.; Holtkamp, N.; Horton-Smith, G.; Huber, P.; Huelsnitz, W.; Imber, J.; Irastorza, I.; Jaeckel, J.; Jaegle, I.; James, C.; Jawahery, A.; Jensen, D.; Jessop, C.P.; Jones, B.; Jostlein, H.; Junk, T.; Kagan, A.L.; Kalita, M.; Kamyshkov, Y.; Kaplan, D.M.; Karagiorgi, G.; Karle, A.; Katori, T.; Kayser, B.; Kephart, R.; Kettell, S.; Kim, Y.K.; Kirby, M.; Kirch, K.; Klein, J.; Kneller, J.; Kobach, A.; Kohl, M.; Kopp, J.; Kordosky, M.; Korsch, W.; Kourbanis, I.; Krisch, A.D.; Krizan, P.; Kronfeld, A.S.; Kulkarni, S.; Kumar, K.S.; Kuno, Y.; Kutter, T.; Lachenmaier, T.; Lamm, M.; Lancaster, J.; Lancaster, M.; Lane, C.; Lang, K.; Langacker, P.; Lazarevic, S.; Le, T.; Lee, K.; Lesko, K.T.; Li, Y.; Lindgren, M.; Lindner, A.; Link, J.; Lissauer, D.; Littenberg, L.S.; Littlejohn, B.; Liu, C.Y.; Loinaz, W.; Lorenzon, W.; Louis, W.C.; Lozier, J.; Ludovici, L.; Lueking, L.; Lunardini, C.; MacFarlane, D.B.; Machado, P.A.N.; Mackenzie, P.B.; Maloney, J.; Marciano, W.J.; Marsh, W.; Marshak, M.; Martin, J.W.; Mauger, C.; McFarland, K.S.; McGrew, C.; McLaughlin, G.; McKeen, D.; McKeown, R.; Meadows, B.T.; Mehdiyev, R.; Melconian, D.; Merkel, H.; Messier, M.; Miller, J.P.; Mills, G.; Minamisono, U.K.; Mishra, S.R.; Mocioiu, I.; Sher, S.Moed; Mohapatra, R.N.; Monreal, B.; Moore, C.D.; Morfin, J.G.; Mousseau, J.; Moustakas, L.A.; Mueller, G.; Mueller, P.; Muether, M.; Mumm, H.P.; Munger, C.; Murayama, H.; Nath, P.; Naviliat-Cuncin, O.; Nelson, J.K.; Neuffer, D.; Nico, J.S.; Norman, A.; Nygren, D.; Obayashi, Y.; O'Connor, T.P.; Okada, Y.; Olsen, J.; Orozco, L.; Orrell, J.L.; Osta, J.; Pahlka, B.; Paley, J.; Papadimitriou, V.; Papucci, M.; Parke, S.; Parker, R.H.; Parsa, Z.; Partyka, K.; Patch, A.; Pati, J.C.; Patterson, R.B.; Pavlovic, Z.; Paz, Gil; Perdue, G.N.; Perevalov, D.; Perez, G.; Petti, R.; Pettus, W.; Piepke, A.; Pivovaroff, M.; Plunkett, R.; Polly, C.C.; Pospelov, M.; Povey, R.; Prakesh, A.; Purohit, M.V.; Raby, S.; Raaf, J.L.; Rajendran, R.; Rajendran, S.; Rameika, G.; Ramsey, R.; Rashed, A.; Ratcliff, B.N.; Rebel, B.; Redondo, J.; Reimer, P.; Reitzner, D.; Ringer, F.; Ringwald, A.; Riordan, S.; Roberts, B.L.; Roberts, D.A.; Robertson, R.; Robicheaux, F.; Rominsky, M.; Roser, R.; Rosner, J.L.; Rott, C.; Rubin, P.; Saito, N.; Sanchez, M.; Sarkar, S.; Schellman, H.; Schmidt, B.; Schmitt, M.; Schmitz, D.W.; Schneps, J.; Schopper, A.; Schuster, P.; Schwartz, A.J.; Schwarz, M.; Seeman, J.; Semertzidis, Y.K.; Seth, K.K.; Shafi, Q.; Shanahan, P.; Sharma, R.; Sharpe, S.R.; Shiozawa, M.; Shiltsev, V.; Sigurdson, K.; Sikivie, P.; Singh, J.; Sivers, D.; Skwarnicki, T.; Smith, N.; Sobczyk, J.; Sobel, H.; Soderberg, M.; Song, Y.H.; Soni, A.; Souder, P.; Sousa, A.; Spitz, J.; Stancari, M.; Stavenga, G.C.; Steffen, J.H.; Stepanyan, S.; Stoeckinger, D.; Stone, S.; Strait, J.; Strassler, M.; Sulai, I.A.; Sundrum, R.; Svoboda, R.; Szczerbinska, B.; Szelc, A.; Takeuchi, T.; Tanedo, P.; Taneja, S.; Tang, J.; Tanner, D.B.; Tayloe, R.; Taylor, I.; Thomas, J.; Thorn, C.; Tian, X.; Tice, B.G.; Tobar, M.; Tolich, N.; Toro, N.; Towner, I.S.; Tsai, Y.; Tschirhart, R.; Tunnell, C.D.; Tzanov, M.; Upadhye, A.; Urheim, J.; Vahsen, S.; Vainshtein, A.; Valencia, E.; Van de Water, R.G.; Van de Water, R.S.; Velasco, M.; Vogel, J.; Vogel, P.; Vogelsang, W.; Wah, Y.W.; Walker, D.; Weiner, N.; Weltman, A.; Wendell, R.; Wester, W.; Wetstein, M.; White, C.; Whitehead, L.; Whitmore, J.; Widmann, E.; Wiedemann, G.; Wilkerson, J.; Wilkinson, G.; Wilson, P.; Wilson, R.J.; Winter, W.; Wise, M.B.; Wodin, J.; Wojcicki, S.; Wojtsekhowski, B.; Wongjirad, T.; Worcester, E.; Wurtele, J.; Xin, T.; Xu, J.; Yamanaka, T.; Yamazaki, Y.; Yavin, I.; Yeck, J.; Yeh, M.; Yokoyama, M.; Yoo, J.; Young, A.; Zimmerman, E.; Zioutas, K.; Zisman, M.; Zupan, J.; Zwaska, R.; Intensity Frontier Workshop

    2012-01-01

    The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.

  16. Progress of the Intense ECR Proton Source

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An intense ECR proton source has been developed to meet the needs of intense proton RFQ. The source is tested on a newly built oil-free and high speed test-bench. The feed of microwave, structure ofionization chamber,HV sparks and especially the problem of BN disc facing plasma is investigated. The

  17. High Intensity Interval Training: New Insights

    Institute of Scientific and Technical Information of China (English)

    Martin J.Gibala

    2008-01-01

    @@ KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief,intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.,≥90%of VO2 peak).

  18. Global Intensity Correction in Dynamic Scenes

    NARCIS (Netherlands)

    Withagen, P.J.; Schutte, K.; Groen, F.C.A.

    2010-01-01

    Changing image intensities causes problems for many computer vision applications operating in unconstrained environments. We propose generally applicable algorithms to correct for global differences in intensity between images recorded with a static or slowly moving camera, regardless of the cause o

  19. Lossless intensity modulation in integrated photonics.

    Science.gov (United States)

    Sandhu, Sunil; Fan, Shanhui

    2012-02-13

    We present a dynamical analysis of lossless intensity modulation in two different ring resonator geometries. In both geometries, we demonstrate modulation schemes that result in a symmetrical output with an infinite on/off ratio. The systems behave as lossless intensity modulators where the time-averaged output optical power is equal to the time-averaged input optical power.

  20. High Intensity Exercise in Multiple Sclerosis

    DEFF Research Database (Denmark)

    Wens, Inez; Dalgas, Ulrik; Vandenabeele, Frank

    2015-01-01

    Introduction Low-to-moderate intensity exercise improves muscle contractile properties and endurance capacity in multiple sclerosis (MS). The impact of high intensity exercise remains unknown. Methods Thirty-four MS patients were randomized into a sedentary control group (SED, n = 11) and 2...