Beyond injection: Trojan horse underdense photocathode plasma wakefield acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hidding, B.; Rosenzweig, J. B.; Xi, Y.

2012-12-21

An overview on the underlying principles of the hybrid plasma wakefield acceleration scheme dubbed 'Trojan Horse' acceleration is given. The concept is based on laser-controlled release of electrons directly into a particle-beam-driven plasma blowout, paving the way for controlled, shapeable electron bunches with ultralow emittance and ultrahigh brightness. Combining the virtues of a low-ionization-threshold underdense photocathode with the GV/m-scale electric fields of a practically dephasing-free beam-driven plasma blowout, this constitutes a 4th generation electron acceleration scheme. It is applicable as a beam brightness transformer for electron bunches from LWFA and PWFA systems alike. At FACET, the proof-of-concept experiment 'E-210: Trojanmore » Horse Plasma Wakefield Acceleration' has recently been approved and is in preparation. At the same time, various LWFA facilities are currently considered to host experiments aiming at stabilizing and boosting the electron bunch output quality via a trojan horse afterburner stage. Since normalized emittance and brightness can be improved by many orders of magnitude, the scheme is an ideal candidate for light sources such as free-electron-lasers and those based on Thomson scattering and betatron radiation alike.« less

Mode-locking observation of a CO2 laser by intracavity plasma injection

NASA Astrophysics Data System (ADS)

John, P. K.; Dembinski, M.

1980-06-01

A TEA CO2 laser was simultaneously Q-switched and mode-locked when an underdense plasma was injected into the cavity. The plasma was produced in an electromagnetic shock tube. Plasma density and temperature were N sub e of approximately 10 to the 17th/cu cm and T sub e of approximately 2 eV, respectively. Phase perturbation of the cavity due to the time dependent plasma refractive index could account for the observed mode-locking.

Measurements of Electron Temperature and Density Profiles of Plasmas Produced by Nike KrF Laser for Laser Plasma Instability (LPI) Research

NASA Astrophysics Data System (ADS)

Oh, Jaechul; Weaver, J. L.; Obenschain, S. P.; Schmitt, A. J.; Kehne, D. M.; Karasik, M.; Chan, L.-Y.; Serlin, V.; Phillips, L.

2012-10-01

ExperimentsfootnotetextJ. Oh, et al, GO5.4, APS DPP (2010).^,footnotetextJ. L. Weaver, et al, GO5.3, APS DPP (2010). using Nike KrF laser observed LPI signatures from CH plasmas at the laser intensities above ˜1x10^15 W/cm^2. Knowing spatial profiles of temperature (Te) and density (ne) in the underdense coronal region (0 < n < nc/4) of the plasma is essential to understanding the LPI observation. However, numerical simulation was the only way to access the profiles for the previous experiments. In the current Nike LPI experiment, a side-on grid imaging refractometer (GIR)footnotetextR. S. Craxton, et al, Phys. Fluids B 5, 4419 (1993). is being deployed for measuring the underdense plasma profiles. The GIR will resolve Te and ne in space taking a 2D snapshot of probe laser (λ= 263 nm, δt = 10 psec) beamlets (50μm spacing) refracted by the plasma at a selected time during the laser illumination. Time-resolved spectrometers with an absolute-intensity-calibrated photodiode array and a streak camera will simultaneously monitor light emission from the plasma in spectral ranges relevant to Raman (SRS) and two plasmon decay (TDP) instabilities. The experimental study of effects of the plasma profiles on the LPI initiation will be presented.

New exact solutions of the Dirac and Klein-Gordon equations of a charged particle propagating in a strong laser field in an underdense plasma

NASA Astrophysics Data System (ADS)

Varró, Sándor

2014-03-01

Exact solutions are presented of the Dirac and Klein-Gordon equations of a charged particle propagating in a classical monochromatic electromagnetic plane wave in a medium of index of refraction nm<1. In the Dirac case the solutions are expressed in terms of new complex polynomials, and in the Klein-Gordon case the found solutions are expressed in terms of Ince polynomials. In each case they form a doubly infinite set, labeled by two integer quantum numbers. These integer numbers represent quantized momentum components of the charged particle along the polarization vector and along the propagation direction of the electromagnetic radiation. Since this radiation may represent a plasmon wave of arbitrary high amplitude, propagating in an underdense plasma, the solutions obtained may have relevance in describing possible quantum features of novel acceleration mechanisms.

Dependence of optimal initial density on laser parameters for multi-keV x-ray radiators generated by nanosecond laser-produced underdense plasma

NASA Astrophysics Data System (ADS)

Tu, Shao-yong; Yuan, Yong-teng; Hu, Guang-yue; Miao, Wen-yong; Zhao, Bin; Zheng, Jian; Jiang, Shao-en; Ding, Yong-kun

2016-01-01

Efficient multi-keV x-ray sources can be produced using nanosecond laser pulse-heated middle-Z underdense plasmas generated using gas or foam. Previous experimental results show that an optimal initial target density exists for efficient multi-keV x-ray emission at which the laser ionization wave is supersonic. Here we explore the influence of the laser intensity and the pulse duration on this optimal initial target density via a one-dimensional radiation hydrodynamic simulation. The simulation shows that the optimal initial density is sensitive to both the laser intensity and the pulse duration. However, the speed of the supersonic ionization wave at the end of the laser irradiation is always maintained at 1.5 to 1.7 times that of the ion acoustic wave under the optimal initial density conditions.

Development of High Fluence, High Conversion Efficiency X-Ray Sources at the National Ignition Facility

NASA Astrophysics Data System (ADS)

May, Mark

2017-10-01

Laser heated millimeter scale targets have provided recently some of the most powerful and energetic laboratory sources of x-ray photons (E = 6 - 24 keV) with high fluence and conversion efficiency (CE). These sources have included the K-shell of stainless steel (E = 5-9 keV) from cylindrical cavities having a CE of 6.8% (Etot 31 kJ), the K-shell of Kr (E = 8-20 keV) from gas pipes having a CE of 1.6% ( 20 kJ) and the L-shell of Ag (E = 3-5 keV) from novel nano-wire foam targets having a CE of 16% ( 81 kJ). The x-ray power and CE are dependent upon the peak electron temperature in the radiating plasma created from these underdense (ne < 0.25 nc) sources. The temperature can be limited by the available laser power and energy which can cause the fluence and the CE to be suboptimal especially for high Z K-shell sources. Cavity targets require several nanoseconds for the underdense plasma to fill the cavity but do have an increase in temperature and emission at late time from plasma stagnation on axis. In contrast the gas or foam targets heat volumetrically to an underdense source in less than a nanosecond which can be more efficient. Both the experimental and simulation details of these high fluence x-ray sources will be discussed. This work was done under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

The interaction of intense subpicosecond laser pulses with underdense plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coverdale, Christine Ann

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 16 W/cm 2 laser pulses. These lasers have provided a new regime in which to study laser-plasma interactions, a regime characterized by L plasma ≥ 2L Rayleigh > cτ. The goal of this dissertation is to experimentally characterize the interaction of a short pulse, high intensity laser with an underdense plasma (n o ≤ 0.05n cr). Specifically, themore » 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.« less

Laser propagation measurements in long-scale-length underdense plasmas relevant to magnetized liner inertial fusion.

PubMed

Harvey-Thompson, A J; Sefkow, A B; Wei, M S; Nagayama, T; Campbell, E M; Blue, B E; Heeter, R F; Koning, J M; Peterson, K J; Schmitt, A

2016-11-01

We report experimental results and simulations showing efficient laser energy coupling into plasmas at conditions relevant to the magnetized liner inertial fusion (MagLIF) concept. In MagLIF, to limit convergence and increase the hydrodynamic stability of the implosion, the fuel must be efficiently preheated. To determine the efficiency and physics of preheating by a laser, an Ar plasma with n_{e}/n_{crit}∼0.04 is irradiated by a multi-ns, multi-kJ, 0.35-μm, phase-plate-smoothed laser at spot-averaged intensities ranging from 1.0×10^{14} to 2.5×10^{14}W/cm^{2} and pulse widths from 2 to 10 ns. Time-resolved x-ray images of the laser-heated plasma are compared to two-dimensional radiation-hydrodynamic simulations that show agreement with the propagating emission front, a comparison that constrains laser energy deposition to the plasma. The experiments show that long-pulse, modest-intensity (I=1.5×10^{14}W/cm^{2}) beams can efficiently couple energy (∼82% of the incident energy) to MagLIF-relevant long-length (9.5 mm) underdense plasmas. The demonstrated heating efficiency is significantly higher than is thought to have been achieved in early integrated MagLIF experiments [A. B. Sefkow et al., Phys. Plasmas 21, 072711 (2014)10.1063/1.4890298].

Laser propagation measurements in long-scale-length underdense plasmas relevant to magnetized liner inertial fusion

NASA Astrophysics Data System (ADS)

Harvey-Thompson, A. J.; Sefkow, A. B.; Wei, M. S.; Nagayama, T.; Campbell, E. M.; Blue, B. E.; Heeter, R. F.; Koning, J. M.; Peterson, K. J.; Schmitt, A.

2016-11-01

We report experimental results and simulations showing efficient laser energy coupling into plasmas at conditions relevant to the magnetized liner inertial fusion (MagLIF) concept. In MagLIF, to limit convergence and increase the hydrodynamic stability of the implosion, the fuel must be efficiently preheated. To determine the efficiency and physics of preheating by a laser, an Ar plasma with ne/nc r i t˜0.04 is irradiated by a multi-ns, multi-kJ, 0.35-μm, phase-plate-smoothed laser at spot-averaged intensities ranging from 1.0 ×1014 to 2.5 ×1014W /c m2 and pulse widths from 2 to 10 ns. Time-resolved x-ray images of the laser-heated plasma are compared to two-dimensional radiation-hydrodynamic simulations that show agreement with the propagating emission front, a comparison that constrains laser energy deposition to the plasma. The experiments show that long-pulse, modest-intensity (I =1.5 ×1014W /c m2 ) beams can efficiently couple energy (˜82 % of the incident energy) to MagLIF-relevant long-length (9.5 mm) underdense plasmas. The demonstrated heating efficiency is significantly higher than is thought to have been achieved in early integrated MagLIF experiments [A. B. Sefkow et al., Phys. Plasmas 21, 072711 (2014), 10.1063/1.4890298].

The effect of external magnetic field on the bremsstrahlung nonlinear absorption mechanism in the interaction of high intensity short laser pulse with collisional underdense plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sedaghat, M.; Ettehadi-Abari, M.; Shokri, B., E-mail: b-shokri@sbu.ac.ir

2015-03-15

Laser absorption in the interaction between ultra-intense femtosecond laser and solid density plasma is studied theoretically here in the intensity range Iλ{sup 2}≃10{sup 14}−10{sup 16}Wcm{sup −2}μm{sup 2}. The collisional effect is found to be significant when the incident laser intensity is less than 10{sup 16}Wcm{sup −2}μm{sup 2}. In the current work, the propagation of a high frequency electromagnetic wave, for underdense collisional plasma in the presence of an external magnetic field is investigated. It is shown that, by considering the effect of the ponderomotive force in collisional magnetized plasmas, the increase of laser pulse intensity leads to steepening of themore » electron density profile and the electron bunches of plasma makes narrower. Moreover, it is found that the wavelength of electric and magnetic fields oscillations increases by increasing the external magnetic field and the density distribution of electrons also grows in comparison with the unmagnetized collisional plasma. Furthermore, the spatial damping rate of laser energy and the nonlinear bremsstrahlung absorption coefficient are obtained in the collisional regime of magnetized plasma. The other remarkable result is that by increasing the external magnetic field in this case, the absorption coefficient increases strongly.« less

Laser propagation measurements in long-scale-length underdense plasmas relevant to magnetized liner inertial fusion

DOE PAGES

Harvey-Thompson, A. J.; Sefkow, A. B.; Wei, M. S.; ...

2016-11-02

Here, we report experimental results and simulations showing efficient laser energy coupling into plasmas at conditions relevant to the magnetized liner inertial fusion (MagLIF) concept. In MagLIF, to limit convergence and increase the hydrodynamic stability of the implosion, the fuel must be efficiently preheated. To determine the efficiency and physics of preheating by a laser, an Ar plasma with n e / n c r i t ~ 0.04 is irradiated by a multi-ns, multi-kJ, 0.35-μm, phase-plate-smoothed laser at spot-averaged intensities ranging from 1.0 × 10 14 to 2.5 × 10 14 W / c m 2 andmore » pulse widths from 2 to 10 ns. Time-resolved x-ray images of the laser-heated plasma are compared to two-dimensional radiation-hydrodynamic simulations that show agreement with the propagating emission front, a comparison that constrains laser energy deposition to the plasma. The experiments show that long-pulse, modest-intensity ( I = 1.5 × 10 14 W / c m 2 ) beams can efficiently couple energy ( ~ 82 % of the incident energy) to MagLIF-relevant long-length (9.5 mm) underdense plasmas. The heating efficiency we demonstrate is significantly higher than it was thought to have been achieved in early integrated MagLIF experiments [A. B. Sefkow et al., Phys. Plasmas 21, 072711 (2014)].« less

Laser propagation measurements in long-scale-length underdense plasmas relevant to magnetized liner inertial fusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey-Thompson, A. J.; Sefkow, A. B.; Wei, M. S.

Here, we report experimental results and simulations showing efficient laser energy coupling into plasmas at conditions relevant to the magnetized liner inertial fusion (MagLIF) concept. In MagLIF, to limit convergence and increase the hydrodynamic stability of the implosion, the fuel must be efficiently preheated. To determine the efficiency and physics of preheating by a laser, an Ar plasma with n e / n c r i t ~ 0.04 is irradiated by a multi-ns, multi-kJ, 0.35-μm, phase-plate-smoothed laser at spot-averaged intensities ranging from 1.0 × 10 14 to 2.5 × 10 14 W / c m 2 andmore » pulse widths from 2 to 10 ns. Time-resolved x-ray images of the laser-heated plasma are compared to two-dimensional radiation-hydrodynamic simulations that show agreement with the propagating emission front, a comparison that constrains laser energy deposition to the plasma. The experiments show that long-pulse, modest-intensity ( I = 1.5 × 10 14 W / c m 2 ) beams can efficiently couple energy ( ~ 82 % of the incident energy) to MagLIF-relevant long-length (9.5 mm) underdense plasmas. The heating efficiency we demonstrate is significantly higher than it was thought to have been achieved in early integrated MagLIF experiments [A. B. Sefkow et al., Phys. Plasmas 21, 072711 (2014)].« less

Investigating the laser heating of underdense plasmas at conditions relevant to MagLIF

NASA Astrophysics Data System (ADS)

Harvey-Thompson, Adam

2015-11-01

The magnetized Liner Inertial Fusion (MagLIF) scheme has achieved thermonuclear fusion yields on Sandia's Z Facility by imploding a cylindrical liner filled with D2 fuel that is preheated with a multi-kJ laser and pre-magnetized with an axial field Bz = 10 T. The challenge of fuel preheating in MagLIF is to deposit several kJ's of energy into an underdense (ne/ncrit<0.1) fusion fuel over ~ 10 mm target length efficiently and without introducing contaminants that could contribute to unacceptable radiative losses during the implosion. Very little experimental work has previously been done to investigate laser heating of gas at densities, scale lengths, modest intensities (Iλ2 ~ 1014 watts- μm2 /cm2) and magnetization parameters (ωceτe ~ 10) necessary for MagLIF. In particular, magnetization of the preheated plasma suppresses electron thermal conduction, which can modify laser energy coupling. Providing an experimental dataset in this regime is essential to not only understand the dynamics of a MagLIF implosion and stagnation, but also to validate magnetized transport models and better understand the physics of laser propagation in magnetized plasmas. In this talk, we present data and analysis of several experiments conducted at OMEGA-EP and at Z to investigate laser propagation and plasma heating in underdense D2 plasmas under a range of conditions, including densities (ne = 0.05-0.1 nc) and magnetization parmaters (ωceτe ~ 0-10). The results show differences in the electron temperature of the heated plasma and the velocity of the laser burn wave with and without an applied magnetic field. We will show comparisons of these experimental results to 2D and 3D HYDRA simulations, which show that the effect of the magnetic field on the electron thermal conduction needs to be taken into account when modeling laser preheat. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

High harmonic generation in underdense plasmas by intense laser pulses with orbital angular momentum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendonça, J. T., E-mail: josetitomend@gmail.com; Vieira, J., E-mail: jorge.vieira@ist.utl.pt

We study high harmonic generation produced by twisted laser pulses, with orbital angular momentum in the relativistic regime, for pulse propagation in underdense plasma. We consider fast time scale processes associated with an ultra-short pulse, where the ion motion can be neglected. We use both analytical models and numerical simulations using a relativistic particle-in-cell code. The present description is valid for relativistic laser intensities, when the normalized field amplitude is much larger than one, a ≫ 1. We also discuss two distinct processes associated with linear and circular polarization. Using both analytical solutions and particle-in-cell simulations, we are able tomore » show that, for laser pulses in a well defined Laguerre-Gauss mode, angular momentum conservation is observed during the process of harmonic generation. Intensity modulation of the harmonic spectrum is also verified, as imposed by the nonlinear time-scale for energy transfer between different harmonics.« less

Laser-driven plasma photonic crystals for high-power lasers

NASA Astrophysics Data System (ADS)

Lehmann, G.; Spatschek, K. H.

2017-05-01

Laser-driven plasma density gratings in underdense plasma are shown to act as photonic crystals for high power lasers. The gratings are created by counterpropagating laser beams that trap electrons, followed by ballistic ion motion. This leads to strong periodic plasma density modulations with a lifetime on the order of picoseconds. The grating structure is interpreted as a plasma photonic crystal time-dependent property, e.g., the photonic band gap width. In Maxwell-Vlasov and particle-in-cell simulations it is demonstrated that the photonic crystals may act as a frequency filter and mirror for ultra-short high-power laser pulses.

Mesure de coefficients d'absorption de plasmas créés par laser nanoseconde

NASA Astrophysics Data System (ADS)

Thais, F.; Chenais-Popovics, C.; Eidmann, K.; Bastiani, S.; Blenski, T.; Gilleron, F.

2005-06-01

La mesure des coefficients d'absorption dans les plasmas chauds est particulièrement utile dans le domaine de la fusion par confinement inertiel ainsi que dans divers contextes en astrophysique. Le développement des calculs de physique atomique qui y sont associés repose sur des hypothèses qu'il est nécessaire de vérifier dans la plus large gamme possible de conditions physiques. Nous présentons ici la méthode de mesure et d'analyse employée en nous appuyant sur l'exemple des cibles multicouches nickel/aluminium.

Single-cycle powerful megawatt to gigawatt terahertz pulse radiated from a wavelength-scale plasma oscillator

NASA Astrophysics Data System (ADS)

Wu, Hui-Chun; Sheng, Zheng-Ming; Zhang, Jie

2008-04-01

We propose a scheme to generate single-cycle powerful terahertz (THz) pulses by ultrashort intense laser pulses obliquely incident on an underdense plasma slab of a few THz wavelengths in thickness. THz waves are radiated from a transient net current driven by the laser ponderomotive force in the plasma slab. Analysis and particle-in-cell simulations show that such a THz source is capable of providing power of megawatts to gigawatts, field strength of MV/cm-GV/cm, and broad tunability range, which is potentially useful for nonlinear and high-field THz science and applications.

Laser-pulse shape effects on magnetic field generation in underdense plasmas

NASA Astrophysics Data System (ADS)

Gopal, Krishna; Raja, Md. Ali; Gupta, Devki Nandan; Avinash, K.; Sharma, Suresh C.

2018-07-01

Laser pulse shape effect has been considered to estimate the self-generated magnetic field in laser-plasma interaction. A ponderomotive force based physical mechanism has been proposed to investigate the self-generated magnetic field for different spatial profiles of the laser pulse in inhomogeneous plasmas. The spatially inhomogeneous electric field of a laser pulse imparts a stronger ponderomotive force on plasma electrons. Thus, the stronger ponderomotive force associated with the asymmetric laser pulse generates a stronger magnetic field in comparison to the case of a symmetric laser pulse. Scaling laws for magnetic field strength with the laser and plasma parameters for different shape of the pulse have been suggested. Present study might be helpful to understand the plasma dynamics relevant to the particle trapping and injection in laser-plasma accelerators.

Calculating the radiation characteristics of accelerated electrons in laser-plasma interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, X. F.; Graduate School of Engineering, Utsunomiya University, 7-1-2 Yohtoh, Utsunomiya 321-8585; Yu, Q.

2016-03-15

In this paper, we studied the characteristics of radiation emitted by electrons accelerated in a laser–plasma interaction by using the Lienard–Wiechert field. In the interaction of a laser pulse with a underdense plasma, electrons are accelerated by two mechanisms: direct laser acceleration (DLA) and laser wakefield acceleration (LWFA). At the beginning of the process, the DLA electrons emit most of the radiation, and the DLA electrons emit a much higher peak photon energy than the LWFA electrons. As the laser–plasma interaction progresses, the LWFA electrons become the major radiation emitter; however, even at this stage, the contribution from DLA electronsmore » is significant, especially to the peak photon energy.« less

Impact of Pre-Plasma on Electron Generation and Transport in Laser Plasma Interactions

NASA Astrophysics Data System (ADS)

Peebles, Jonathan Lee

Relativistic laser plasma interactions in conjunction with an underdense pre-plasma have been shown to generate a two temperature component electron spectrum. The lower temperature component described by "ponderomotive scaling'" is relatively well known and understood and is useful for applications such as the fast ignition inertial confinement fusion scheme. The higher energy electrons generated due to pre-plasma are denoted as "super-ponderomotive" electrons and facilitate interesting and useful applications. These include but are not limited to table top particle acceleration and generating high energy protons, x-rays and neutrons from secondary interactions. This dissertation describes experimental and particle-in-cell computational studies of the electron spectra produced from interactions between short pulse high intensity lasers and controlled pre-plasma conditions. Experiments were conducted at 3 laser labs: Texas Petawatt (University of Texas at Austin), Titan (Lawrence Livermore National Laboratory) and OMEGA-EP (University of Rochester). These lasers have different capabilities, and multiple experiments were carried out in order to fully understand super-ponderomotive electron generation and transport in the high intensity laser regime (I > 1018 W/cm2). In these experiments, an additional secondary long pulse beam was used to generate different scale lengths of "injected" pre-plasma while the pulse length and intensity of the short pulse beam were varied. The temperature and quantity of super-ponderomotive electrons were monitored with magnetic spectrometers and inferred via bremsstrahlung spectrometers while trajectory was estimated via Cu-Kalpha imaging. The experimental and simulation data show that super-ponderomotive electrons require pulse lengths of at least 450 fs to be accelerated and that higher intensity interactions generate large magnetic fields which cause severe deflection of the super-ponderomotive electrons. Laser incidence angle is shown to be extremely important in determining hot electron trajectory. Longer pulse length data taken on OMEGA-EP and Titan showed that super-ponderomotive electrons could be created without the need for an initial pre-plasma due to the underdense plasma created during the high intensity interaction alone.

Non-stationary self-focusing of intense laser beam in plasma using ramp density profile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habibi, M.; Ghamari, F.

2011-10-15

The non-stationary self-focusing of high intense laser beam in under-dense plasma with upward increasing density ramp is investigated. The obtained results show that slowly increasing plasma density ramp is very important in enhancing laser self-focusing. Also, the spot size oscillations of laser beam in front and rear of the pulse for two different density profiles are shown. We have selected density profiles that already were used by Sadighi-Bonabi et al.[Phys. Plasmas 16, 083105 (2009)]. Ramp density profile causes the laser beam to become more focused and penetrations deeps into the plasma by reduction of diffraction effects. Our computations show moremore » reliable results in comparison to the previous works.« less

Plasma Wake-field Acceleration in the Blow-out Regime

NASA Astrophysics Data System (ADS)

Barov, Nikolai; Rosenzweig, James

1999-11-01

Recent experiments at Argonne National Laboratory, investigating the blow-out regime of the plasma wake-field accelerator, are discussed. These experiments achieved stable underdense (beam denser than the ambient plasma density) beam transport, and measured average acceleration of 25 MV/m, corresponding to peak wave fields of over 60 MVm. A comparison of the results to simulation is given, and the physics of the system is discussed. Potential for improvements in performance and achieved acceleration gradient, as well as accelerated beam quality are examined within the context of the next generation of experiments at the Fermilab Test Facility. The status of these experiments will be given.

Characterization of plasma wake excitation and particle trapping in the nonlinear bubble regime

NASA Astrophysics Data System (ADS)

Benedetti, Carlo; Schroeder, Carl; Esarey, Eric; Leemans, Wim

2010-11-01

We investigate the excitation of nonlinear wake (bubble) formation by an ultra-short (kpL ˜2), intense (e Alaser/mc^2 > 2) laser pulse interacting with an underdense plasma. A detailed analysis of particle orbits in the wakefield is performed by using reduced analytical models and numerical simulations performed with the 2D cylindrical, envelope, ponderomotive, hybrid PIC/fluid code INF&RNO, recently developed at LBNL. In particular we study the requirements for injection and/or trapping of background plasma electrons in the nonlinear wake. Characterization of the phase-space properties of the injected particle bunch will also be discussed.

Plasma optical modulators for intense lasers

PubMed Central

Yu, Lu-Le; Zhao, Yao; Qian, Lie-Jia; Chen, Min; Weng, Su-Ming; Sheng, Zheng-Ming; Jaroszynski, D. A.; Mori, W. B.; Zhang, Jie

2016-01-01

Optical modulators can have high modulation speed and broad bandwidth, while being compact. However, these optical modulators usually work for low-intensity light beams. Here we present an ultrafast, plasma-based optical modulator, which can directly modulate high-power lasers with intensity up to 1016 W cm−2 to produce an extremely broad spectrum with a fractional bandwidth over 100%, extending to the mid-infrared regime in the low-frequency side. This concept relies on two co-propagating laser pulses in a sub-millimetre-scale underdense plasma, where a drive laser pulse first excites an electron plasma wave in its wake while a following carrier laser pulse is modulated by the plasma wave. The laser and plasma parameters suitable for the modulator to work are based on numerical simulations. PMID:27283369

Relativistic Eulerian Vlasov simulations of the amplification of seed pulses by Brillouin backscattering in plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shoucri, M., E-mail: Shoucri.Magdi@ireq.ca; Matte, J.-P.; Vidal, F.

We apply an Eulerian Vlasov code to study the amplification by Brillouin scattering of a short seed laser pulse by a long pump laser pulse in an underdense plasma. The stimulated Brillouin backscattering interaction is the coupling of the pump and seed electromagnetic waves propagating in opposite directions, and the ion plasma wave. The code solves the one-dimensional relativistic Vlasov-Maxwell set of equations. Large amplitude ion waves are generated. In the simulations we present, the density plateau of the plasma is n{sub e}=0.3 n{sub c} (n{sub c} is the critical density), which excludes spurious stimulated Raman scattering amplification (which can occurmore » only if n{sub e}« less

Propagation of an ultra-short, intense laser in a relativistic fluid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ritchie, A.B.; Decker, C.D.

1997-12-31

A Maxwell-relativistic fluid model is developed to describe the propagation of an ultrashort, intense laser pulse through an underdense plasma. The model makes use of numerically stabilizing fast Fourier transform (FFT) computational methods for both the Maxwell and fluid equations, and it is benchmarked against particle-in-cell (PIC) simulations. Strong fields generated in the wake of the laser are calculated, and the authors observe coherent wake-field radiation generated at harmonics of the plasma frequency due to nonlinearities in the laser-plasma interaction. For a plasma whose density is 10% of critical, the highest members of the plasma harmonic series begin to overlapmore » with the first laser harmonic, suggesting that widely used multiple-scales-theory, by which the laser and plasma frequencies are assumed to be separable, ceases to be a useful approximation.« less

Laser singular Theta-pinch

NASA Astrophysics Data System (ADS)

Okulov, A. Yu.

2010-10-01

The interaction of the two counter-propagating ultrashort laser pulses with singular wavefronts in the thin slice of the underdense plasma is considered. It is shown that ion-acoustic wave is excited via Brillouin three-wave resonance by corkscrew interference pattern of paraxial singular laser beams. The orbital angular momentum carried by light is transferred to plasma ion-acoustic vortex. The rotation of the density perturbations of electron fluid is the cause of helical current which produces the kilogauss axial quasi-static magnetic field. The exact analytical configurations are presented for an ion-acoustic current field and magnetic induction. The range of experimentally accessible parameters is evaluated.

1997 Technical Digest Series. Volume 7: Applications of High Field and Short Wavelength Sources VII

DTIC Science & Technology

1997-03-01

clusters irradiated with ultrashort , high intensity laser pulses can exhibit "ionization ig- nition" which leads...8, 9]. 25-atom Ne clusters and 25-atom Ar clusters are modelled as irradiated by a 800 nm, 15 fs (fwhm) laser pulse with peak intensities ranging...Measurements of the spatial and spectral properties of ultrashort , intense laser pulses propagating in underdense plasmas demonstrate

Multiscale Magnetic Underdense Regions on the Solar Surface: Granular and Mesogranular Scales

NASA Astrophysics Data System (ADS)

Berrilli, F.; Scardigli, S.; Giordano, S.

2013-02-01

The Sun is a non-equilibrium, dissipative system subject to an energy flow that originates in its core. Convective overshooting motions create temperature and velocity structures that show a temporal and spatial multiscale evolution. As a result, photospheric structures are generally considered to be a direct manifestation of convective plasma motions. The plasma flows in the photosphere govern the motion of single magnetic elements. These elements are arranged in typical patterns, which are observed as a variety of multiscale magnetic patterns. High-resolution magnetograms of the quiet solar surface revealed the presence of multiscale magnetic underdense regions in the solar photosphere, commonly called voids, which may be considered to be a signature of the underlying convective structure. The analysis of such patterns paves the way for the investigation of all turbulent convective scales, from granular to global. In order to address the question of magnetic structures driven by turbulent convection at granular and mesogranular scales, we used a voids-detection method. The computed distribution of void length scales shows an exponential behavior at scales between 2 and 10 Mm and the absence of features at mesogranular scales. The absence of preferred scales of organization in the 2 - 10 Mm range supports the multiscale nature of flows on the solar surface and the absence of a mesogranular convective scale.

Frequency up-conversion of a high-power microwave pulse propagating in a self-generated plasma

NASA Technical Reports Server (NTRS)

Kuo, S. P.; Ren, A.

1992-01-01

In the study of the propagation of a high-power microwave pulse, one of the main concerns is how to minimize the energy loss of the pulse before reaching the destination. A frequency autoconversion process that can lead to reflectionless propagation of powerful electromagnetic pulses in self-generated plasmas is studied. The theory shows that, under the proper condition, the carrier frequency omega of the pulse shifts upward during the growth of local plasma frequency omega(pe). Thus, the self-generated plasma remains underdense to the pulse. A chamber experiment to demonstrate the frequency autoconversion during the pulse propagation through the self-generated plasma is conducted. The detected frequency shift is compared with the theoretical result calculated by using the measured electron density distribution along the propagation path of the pulse. Good agreement is obtained.

Propagation of an ultrashort, intense laser pulse in a relativistic plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ritchie, B.; Decker, C.D.

1997-12-31

A Maxwell-relativistic fluid model is developed for the propagation of an ultrashort, intense laser pulse through an underdense plasma. The separability of plasma and optical frequencies ({omega}{sub p} and {omega} respectively) for small {omega}{sub p}/{omega} is not assumed; thus the validity of multiple-scales theory (MST) can be tested. The theory is valid when {omega}{sub p}/{omega} is of order unity or for cases in which {omega}{sub p}/{omega} {much_lt} 1 but strongly relativistic motion causes higher-order plasma harmonics to be generated which overlap the region of the first-order laser harmonic, such that MST would not expected to be valid although its principalmore » validity criterion {omega}{sub p}/{omega} {much_lt} 1 holds.« less

Transition from wakefield generation to soliton formation.

PubMed

Holkundkar, Amol R; Brodin, Gert

2018-04-01

It is well known that when a short laser pulse propagates in an underdense plasma, it induces longitudinal plasma oscillations at the plasma frequency after the pulse, typically referred to as the wakefield. However, for plasma densities approaching the critical density, wakefield generation is suppressed, and instead the EM-pulse (electromagnetic pulse) undergoes nonlinear self-modulation. In this article we have studied the transition from the wakefield generation to formation of quasi-solitons as the plasma density is increased. For this purpose we have applied a one-dimensional relativistic cold fluid model, which has also been compared with particle-in-cell simulations. A key result is that the energy loss of the EM-pulse due to wakefield generation has its maximum for a plasma density of the order 10% of the critical density, but that wakefield generation is sharply suppressed when the density is increased further.

Transition from wakefield generation to soliton formation

NASA Astrophysics Data System (ADS)

Holkundkar, Amol R.; Brodin, Gert

2018-04-01

It is well known that when a short laser pulse propagates in an underdense plasma, it induces longitudinal plasma oscillations at the plasma frequency after the pulse, typically referred to as the wakefield. However, for plasma densities approaching the critical density, wakefield generation is suppressed, and instead the EM-pulse (electromagnetic pulse) undergoes nonlinear self-modulation. In this article we have studied the transition from the wakefield generation to formation of quasi-solitons as the plasma density is increased. For this purpose we have applied a one-dimensional relativistic cold fluid model, which has also been compared with particle-in-cell simulations. A key result is that the energy loss of the EM-pulse due to wakefield generation has its maximum for a plasma density of the order 10% of the critical density, but that wakefield generation is sharply suppressed when the density is increased further.

Inhibition of stimulated Raman scattering due to the excitation of stimulated Brillouin scattering

NASA Astrophysics Data System (ADS)

Zhao, Yao; Yu, Lu-Le; Weng, Su-Ming; Ren, Chuang; Liu, Chuan-Sheng; Sheng, Zheng-Ming

2017-09-01

The nonlinear coupling between stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) of intense laser in underdense plasma is studied theoretically and numerically. Based upon the fluid model, their coupling equations are derived, and a threshold condition of plasma density perturbations due to SBS for the inhibition of SRS is given. Particle-in-cell simulations show that this condition can be achieved easily by SBS in the so-called fluid regime with kLλD<0.15 , where kL is the Langmuir wave number and λD is the Debye length [Kline et al., Phys. Plasmas 13, 055906 (2006)]. SBS can reduce the saturation level of SRS and the temperature of electrons in both homogeneous and inhomogeneous plasma. Numerical simulations also show that this reduced SRS saturation is retained even if the fluid regime condition mentioned above is violated at a later time due to plasma heating.

Measurements of laser-hole boring into overdense plasmas using x-ray laser refractometry (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kodama, R.; Takahashi, K.; Tanaka, K.A.

We developed a 19.6 nm laser x-ray laser grid-image refractometer (XRL-GIR) to diagnose laser-hole boring into overdense plasmas. The XRL-GIR was optimized to measure two-dimensional electron density perturbation on a scale of a few tens of {mu}m in underdense plasmas. Electron density profiles of laser-produced plasmas were obtained for 10{sup 20}{endash}10{sup 22}thinspcm{sup {minus}3} with the XRL-GIR and for 10{sup 19}{endash}10{sup 20}thinspcm{sup {minus}3} from an ultraviolet interferometer, the profiles of which were compared with those from hydrodynamic simulation. By using this XRL-GIR, we directly observed laser channeling into overdense plasmas accompanied by a bow shock wave showing a Mach cone ascribedmore » to supersonic propagation of the channel front. {copyright} {ital 1999 American Institute of Physics.}« less

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

PubMed Central

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

2016-01-01

Ion acceleration from intense (Iλ2 > 1018 Wcm−2 μm2) 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. PMID:27531755

Efficient Modeling of Laser-Plasma Accelerators with INF&RNO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benedetti, C.; Schroeder, C. B.; Esarey, E.

2010-06-01

The numerical modeling code INF&RNO (INtegrated Fluid& paRticle simulatioN cOde, pronounced"inferno") is presented. INF&RNO is an efficient 2D cylindrical code to model the interaction of a short laser pulse with an underdense plasma. The code is based on an envelope model for the laser while either a PIC or a fluid description can be used for the plasma. The effect of the laser pulse on the plasma is modeled with the time-averaged poderomotive force. These and other features allow for a speedup of 2-4 orders of magnitude compared to standard full PIC simulations while still retaining physical fidelity. The codemore » has been benchmarked against analytical solutions and 3D PIC simulations and here a set of validation tests together with a discussion of the performances are presented.« less

Efficient Modeling of Laser-Plasma Accelerators with INF&RNO

NASA Astrophysics Data System (ADS)

Benedetti, C.; Schroeder, C. B.; Esarey, E.; Geddes, C. G. R.; Leemans, W. P.

2010-11-01

The numerical modeling code INF&RNO (INtegrated Fluid & paRticle simulatioN cOde, pronounced "inferno") is presented. INF&RNO is an efficient 2D cylindrical code to model the interaction of a short laser pulse with an underdense plasma. The code is based on an envelope model for the laser while either a PIC or a fluid description can be used for the plasma. The effect of the laser pulse on the plasma is modeled with the time-averaged poderomotive force. These and other features allow for a speedup of 2-4 orders of magnitude compared to standard full PIC simulations while still retaining physical fidelity. The code has been benchmarked against analytical solutions and 3D PIC simulations and here a set of validation tests together with a discussion of the performances are presented.

Ultrarelativistic electromagnetic pulses in plasmas

NASA Technical Reports Server (NTRS)

Ashour-Abdalla, M.; Leboeuf, J. N.; Tajima, T.; Dawson, J. M.; Kennel, C. F.

1981-01-01

The physical processes of a linearly polarized electromagnetic pulse of highly relativistic amplitude in an underdense plasma accelerating particles to very high energies are studied through computer simulation. An electron-positron plasma is considered first. The maximum momenta achieved scale as the square of the wave amplitude. This acceleration stops when the bulk of the wave energy is converted to particle energy. The pulse leaves behind as a wake a vacuum region whose length scales as the amplitude of the wave. The results can be explained in terms of a snow plow or piston-like action of the radiation on the plasma. When a mass ratio other than unity is chosen and electrostatic effects begin to play a role, first the ion energy increases faster than the electron energy and then the electron energy catches up later, eventually reaching the same value.

Study of laser preheating dependence on laser wavelength and intensity for MagLIF

NASA Astrophysics Data System (ADS)

Wei, M. S.; Harvey-Thompson, A. J.; Glinsky, M.; Nagayama, T.; Weis, M.; Geissel, M.; Peterson, K.; Fooks, J.; Krauland, C.; Giraldez, E.; Davies, J.; Campbell, E. M.; Bahr, R.; Edgell, D.; Stoeckl, C.; Glebov, V.; Emig, J.; Heeter, R.; Strozzi, D.

2017-10-01

The magnetized liner inertial fusion (MagLIF) scheme requires preheating underdense fuel to 100's eV temperature by a TW-scale long pulse laser via collisional absorption. To better understand how laser preheat scales with laser wavelength and intensity as well as to provide data for code validation, we have conducted a well-characterized experiment on OMEGA to directly compare laser propagation, energy deposition and laser plasma instabilities (LPI) using 2 ω (527 nm) and 3 ω (351 nm) lasers with intensity in the range of (1-5)x1014 Wcm-2. The laser beam (1 - 1.5 ns square pulse) enters the gas-filled plastic liner though a 2-µm thick polyimide window to heat an underdense Ar-doped deuterium gas with electron density of 5.5% of critical density. Laser propagation and plasma temperature are diagnosed by time-resolved 2D x-ray images and Ar emission spectroscopy, respectively. LPI is monitored by backscattering and hard x-ray diagnostics. The 2 ω beam propagation shows a noticeable larger lateral spread than the 3 ω beam, indicating laser spray due to filamentation. LPI is observed to increase with laser intensity and the 2 ω beam produces more hot electrons compared with the 3 ω beam under similar conditions. Results will be compared with radiation hydrodynamic simulations. Work supported by the U.S. DOE ARPA-E and NNSA.

Brillouin Scattering of Picosecond Laser Pulses in Preformed, Short-Scale-Length Plasmas

NASA Astrophysics Data System (ADS)

Gaeris, A. C.; Fisher, Y.; Delettrez, J. A.; Meyerhofer, D. D.

1996-11-01

Brillouin scattering (BS) has been studied in short-scale-length, preformed plasmas. The backscattered and specularly reflected light resulting from the interaction of high-power picosecond pulses with preformed silicon plasmas has been measured. A first laser pulse forms a short-scale-length plasma -- without significant BS -- while a second delayed pulse interacts with an expanded, drifting underdense region of the plasma with density scale length (0 <= Ln <= 600 λ _L). The pulses are generated at λ L = 1054 nm, with intensities up to 10^16 W/cm^2. The backscattered light spectra, threshold intensities, and enhanced reflectivities have been determined for different plasma-density scale lengths and are compared to Liu, Rosenbluth, and White's(C. S. Liu, M. N. Rosenbluth, and R. B. White, Phys. Fluids 17, 1211 (1974).) WKB treatment of stimulated Brillouin scattering in inhomogeneous drifting plasmas. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

Measurements of electron density and temperature profiles in plasma produced by Nike KrF laser for laser plasma instability research

NASA Astrophysics Data System (ADS)

Oh, Jaechul; Weaver, J. L.; Karasik, M.; Chan, L. Y.

2015-08-01

A grid image refractometer (GIR) has been implemented at the Nike krypton fluoride laser facility of the Naval Research Laboratory. This instrument simultaneously measures propagation angles and transmissions of UV probe rays (λ = 263 nm, Δt = 10 ps) refracted through plasma. We report results of the first Nike-GIR measurement on a CH plasma produced by the Nike laser pulse (˜1 ns FWHM) with the intensity of 1.1 × 1015 W/cm2. The measured angles and transmissions were processed to construct spatial profiles of electron density (ne) and temperature (Te) in the underdense coronal region of the plasma. Using an inversion algorithm developed for the strongly refracted rays, the deployed GIR system probed electron densities up to 4 × 1021 cm-3 with the density scale length of 120 μm along the plasma symmetry axis. The resulting ne and Te profiles are verified to be self-consistent with the measured quantities of the refracted probe light.

A new class of exact solutions of the Klein-Gordon equation of a charged particle interacting with an electromagnetic plane wave in a medium

NASA Astrophysics Data System (ADS)

Varró, Sándor

2014-01-01

Exact solutions are presented of the Klein-Gordon equation of a charged particle moving in a transverse monochromatic plasmon wave of arbitrary high amplitude, which propagates in an underdense plasma. These solutions are expressed in terms of Ince polynomials, forming a doubly infinite set, parametrized by discrete momentum components of the charged particle’s de Broglie wave along the polarization vector and along the propagation direction of the plasmon radiation. The envelope of the exact wavefunctions describes a high-contrast periodic structure of the particle density on the plasma length scale, which may have relevance in novel particle acceleration mechanisms.

Threshold for electron self-injection in a nonlinear laser-plasma accelerator

NASA Astrophysics Data System (ADS)

Benedetti, Carlo; Schroeder, Carl; Esarey, Eric; Leemans, Wim

2012-10-01

The process of electron self-injection in the nonlinear bubble-wake generated by a short and intense laser pulse propagating in an uniform underdense plasma is investigated. A detailed analysis of particle orbit in the wakefield is performed by using reduced analytical models and numerical simulations carried out with the 2D cylindrical, envelope, ponderomotive, hybrid PIC/fluid code INF&RNO. In particular, we consider a wake generated by a frozen (non-evolving) laser driver traveling with a prescribed velocity, which then sets the properties of the wake, so the injection dynamics is decoupled from driver evolution but a realistic structure for the wakefield is retained. We investigate the dependence of the injection threshold on laser intensity, plasma temperature and wake velocity for a range of parameters of interest for current and future laser plasma accelerators. The phase-space properties of the injected particle bunch will also be discussed.

Efficient Modeling of Laser-Plasma Accelerators with INF and RNO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benedetti, C.; Schroeder, C. B.; Esarey, E.

2010-11-04

The numerical modeling code INF and RNO (INtegrated Fluid and paRticle simulatioN cOde, pronounced 'inferno') is presented. INF and RNO is an efficient 2D cylindrical code to model the interaction of a short laser pulse with an underdense plasma. The code is based on an envelope model for the laser while either a PIC or a fluid description can be used for the plasma. The effect of the laser pulse on the plasma is modeled with the time-averaged poderomotive force. These and other features allow for a speedup of 2-4 orders of magnitude compared to standard full PIC simulations whilemore » still retaining physical fidelity. The code has been benchmarked against analytical solutions and 3D PIC simulations and here a set of validation tests together with a discussion of the performances are presented.« less

Distributions of underdense meteor trail amplitudes and its application to meteor scatter communication system design

NASA Astrophysics Data System (ADS)

Weitzen, J. A.; Bourque, S.; Ostergaard, J. C.; Bench, P. M.; Baily, A. D.

1991-04-01

Analysis of data from recent experiments leads to the observation that distributions of underdense meteor trail peak signal amplitudes differ from classic predictions. In this paper the distribution of trail amplitudes in decibels relative 1 W (dBw) is considered, and it is shown that Lindberg's theorem can be used to apply central limit arguments to this problem. It is illustrated that a Gaussian model for the distribution of the logarithm of the peak received signal level of underdense trails provides a better fit to data than classic approaches. Distributions of underdense meteor trail amplitudes at five frequencies are compared to a Gaussian distribution and the classic model. Implications of the Gaussian assumption on the design of communication systems are discussed.

Characteristics of plasma plume in ultrafast laser ablation with a weakly ionized air channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hou, Huaming; Yang, Bo; Mao, Xianglei

We report the influence of femtosecond (fs) laser weakly ionized air channel on characteristics of plasma induced from fs-laser ablation of solid Zr metal target. A novel method to create high temperature, low electron density plasma with intense elemental emission and weak bremsstrahlung emission was demonstrated. Weakly ionized air channel was generated as a result of a non-linear phenomenon. Two-dimensional time-resolved optical-emission images of plasma plumes were taken for plume dynamics analysis. Dynamic physical properties of filament channels were simulated. In particular, we investigated the influence of weakly ionized air channel on the evolution of solid plasma plume. Plasma plumemore » splitting was observed whilst longer weakly ionized air channel formed above the ablation spot. The domination mechanism for splitting is attributed to the long-lived underdense channel created by fs-laser induced weakly ionization of air. The evolutions of atomic/molecular emission intensity, peak broadening, and plasma temperature were analyzed, and the results show that the part of plasma entering weakly ionized air channel features higher initial temperature, lower electron density and faster decay.« less

Characteristics of plasma plume in ultrafast laser ablation with a weakly ionized air channel

DOE PAGES

Hou, Huaming; Yang, Bo; Mao, Xianglei; ...

2018-05-10

We report the influence of femtosecond (fs) laser weakly ionized air channel on characteristics of plasma induced from fs-laser ablation of solid Zr metal target. A novel method to create high temperature, low electron density plasma with intense elemental emission and weak bremsstrahlung emission was demonstrated. Weakly ionized air channel was generated as a result of a non-linear phenomenon. Two-dimensional time-resolved optical-emission images of plasma plumes were taken for plume dynamics analysis. Dynamic physical properties of filament channels were simulated. In particular, we investigated the influence of weakly ionized air channel on the evolution of solid plasma plume. Plasma plumemore » splitting was observed whilst longer weakly ionized air channel formed above the ablation spot. The domination mechanism for splitting is attributed to the long-lived underdense channel created by fs-laser induced weakly ionization of air. The evolutions of atomic/molecular emission intensity, peak broadening, and plasma temperature were analyzed, and the results show that the part of plasma entering weakly ionized air channel features higher initial temperature, lower electron density and faster decay.« less

Influence of the electron density on the characteristics of terahertz waves generated under laser–cluster interaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frolov, A. A., E-mail: frolov@ihed.ras.ru

2016-12-15

A theory of generation of terahertz radiation under laser–cluster interaction, developed earlier for an overdense cluster plasma [A. A. Frolov, Plasma Phys. Rep. 42. 637 (2016)], is generalized for the case of arbitrary electron density. The spectral composition of radiation is shown to substantially depend on the density of free electrons in the cluster. For an underdense cluster plasma, there is a sharp peak in the terahertz spectrum at the frequency of the quadrupole mode of a plasma sphere. As the electron density increases to supercritical values, this spectral line vanishes and a broad maximum at the frequency comparable withmore » the reciprocal of the laser pulse duration appears in the spectrum. The dependence of the total energy of terahertz radiation on the density of free electrons is analyzed. The radiation yield is shown to increase significantly under resonance conditions, when the laser frequency is close to the eigenfrequency of the dipole or quadrupole mode of a plasma sphere.« less

Producing High Intense Attosecond Pulse Train by Interaction of Three-Color Pulse and Overdense Plasma

NASA Astrophysics Data System (ADS)

Salehi, M.; Mirzanejad, S.

2017-05-01

Amplifying the attosecond pulse by the chirp pulse amplification method is impossible. Furthermore, the intensity of attosecond pulse is low in the interaction of laser pulse and underdense plasma. This motivates us to propose using a multi-color pulse to produce the high intense attosecond pulse. In the present study, the relativistic interaction of a three-color linearly-polarized laser-pulse with highly overdense plasma is studied. We show that the combination of {{ω }}1, {{ω }}2 and {{ω }}3 frequencies decreases the instance full width at half maximum reflected attosecond pulse train from the overdense plasma surface. Moreover, we show that the three-color pulse increases the intensity of generated harmonics, which is explained by the relativistic oscillating mirror model. The obtained results demonstrate that if the three-color laser pulse interacts with overdense plasma, it will enhance two orders of magnitude of intensity of ultra short attosecond pulses in comparison with monochromatic pulse.

Parametric decay instability near the upper hybrid resonance in magnetically confined fusion plasmas

NASA Astrophysics Data System (ADS)

Hansen, S. K.; Nielsen, S. K.; Salewski, M.; Stejner, M.; Stober, J.; the ASDEX Upgrade Team

2017-10-01

In this paper we investigate parametric decay of an electromagnetic pump wave into two electrostatic daughter waves, particularly an X-mode pump wave decaying into a warm upper hybrid wave (a limit of an electron Bernstein wave) and a warm lower hybrid wave. We describe the general theory of the above parametric decay instability (PDI), unifying earlier treatments, and show that it may occur in underdense and weakly overdense plasmas. The PDI theory is used to explain anomalous sidebands observed in collective Thomson scattering (CTS) spectra at the ASDEX Upgrade tokamak. The theory may also account for similar observations during CTS experiments in stellarators, as well as in some 1st harmonic electron cyclotron resonance and O-X-B heating experiments.

Thomson-Scattering Study of the Subharmonic Decay of Ion-Acoustic Waves Driven by the Brillouin Instability

NASA Astrophysics Data System (ADS)

Bandulet, H. C.; Labaune, C.; Lewis, K.; Depierreux, S.

2004-07-01

Thomson scattering (TS) has been used to investigate the two-ion decay instability of ion acoustic waves generated by stimulated Brillouin scattering in an underdense CH plasma. Two complementary TS diagnostics, spectrally and spatially resolved, demonstrate the occurrence of the subharmonic decay of the primary ion acoustic wave into two secondary waves. The study of the laser intensity dependence shows that the secondary ion acoustic waves are correlated with the SBS reflectivity saturation, at a level of a few percent.

Predicting pulsar scintillation from refractive plasma sheets

NASA Astrophysics Data System (ADS)

Simard, Dana; Pen, Ue-Li

2018-07-01

The dynamic and secondary spectra of many pulsars show evidence for long-lived, aligned images of the pulsar that are stationary on a thin scattering sheet. One explanation for this phenomenon considers the effects of wave crests along sheets in the ionized interstellar medium, such as those due to Alfvén waves propagating along current sheets. If these sheets are closely aligned to our line of sight to the pulsar, high bending angles arise at the wave crests and a selection effect causes alignment of images produced at different crests, similar to grazing reflection off of a lake. Using geometric optics, we develop a simple parametrized model of these corrugated sheets that can be constrained with a single observation and that makes observable predictions for variations in the scintillation of the pulsar over time and frequency. This model reveals qualitative differences between lensing from overdense and underdense corrugated sheets: only if the sheet is overdense compared to the surrounding interstellar medium can the lensed images be brighter than the line-of-sight image to the pulsar, and the faint lensed images are closer to the pulsar at higher frequencies if the sheet is underdense, but at lower frequencies if the sheet is overdense.

Predicting Pulsar Scintillation from Refractive Plasma Sheets

NASA Astrophysics Data System (ADS)

Simard, Dana; Pen, Ue-Li

2018-05-01

The dynamic and secondary spectra of many pulsars show evidence for long-lived, aligned images of the pulsar that are stationary on a thin scattering sheet. One explanation for this phenomenon considers the effects of wave crests along sheets in the ionized interstellar medium, such as those due to Alfvén waves propagating along current sheets. If these sheets are closely aligned to our line-of-sight to the pulsar, high bending angles arise at the wave crests and a selection effect causes alignment of images produced at different crests, similar to grazing reflection off of a lake. Using geometric optics, we develop a simple parameterized model of these corrugated sheets that can be constrained with a single observation and that makes observable predictions for variations in the scintillation of the pulsar over time and frequency. This model reveals qualitative differences between lensing from overdense and underdense corrugated sheets: Only if the sheet is overdense compared to the surrounding interstellar medium can the lensed images be brighter than the line-of-sight image to the pulsar, and the faint lensed images are closer to the pulsar at higher frequencies if the sheet is underdense, but at lower frequencies if the sheet is overdense.

Measurements of electron density and temperature profiles in plasma produced by Nike KrF laser for laser plasma instability research.

PubMed

Oh, Jaechul; Weaver, J L; Karasik, M; Chan, L Y

2015-08-01

A grid image refractometer (GIR) has been implemented at the Nike krypton fluoride laser facility of the Naval Research Laboratory. This instrument simultaneously measures propagation angles and transmissions of UV probe rays (λ = 263 nm, Δt = 10 ps) refracted through plasma. We report results of the first Nike-GIR measurement on a CH plasma produced by the Nike laser pulse (∼1 ns FWHM) with the intensity of 1.1 × 10(15) W/cm(2). The measured angles and transmissions were processed to construct spatial profiles of electron density (ne) and temperature (Te) in the underdense coronal region of the plasma. Using an inversion algorithm developed for the strongly refracted rays, the deployed GIR system probed electron densities up to 4 × 10(21) cm(-3) with the density scale length of 120 μm along the plasma symmetry axis. The resulting n(e) and T(e) profiles are verified to be self-consistent with the measured quantities of the refracted probe light.

Propagation characteristics of two-color laser pulses in homogeneous plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemlata,; Saroch, Akanksha; Jha, Pallavi

2015-11-15

An analytical and numerical study of the evolution of two-color, sinusoidal laser pulses in cold, underdense, and homogeneous plasma has been presented. The wave equations for the radiation fields driven by linear as well as nonlinear contributions due to the two-color laser pulses have been set up. A variational technique is used to obtain the simultaneous equations describing the evolution of the laser spot size, pulse length, and chirp parameter. Numerical methods are used to graphically analyze the simultaneous evolution of these parameters due to the combined effect of the two-color laser pulses. Further, the pulse parameters are compared withmore » those obtained for a single laser pulse. Significant focusing, compression, and enhanced positive chirp is obtained due to the combined effect of simultaneously propagating two-color pulses as compared to a single pulse propagating in plasma.« less

Diagnosing laser-preheated magnetized plasmas relevant to magnetized liner inertial fusion

DOE PAGES

Harvey-Thompson, Adam James; Sefkow, Adam B.; Nagayama, Taisuke N.; ...

2015-12-22

In this paper, we present a platform on the OMEGA EP Laser Facility that creates and diagnoses the conditions present during the preheat stage of the MAGnetized Liner Inertial Fusion (MagLIF) concept. Experiments were conducted using 9 kJ of 3ω (355 nm) light to heat an underdense deuterium gas (electron density: 2.5 × 10 20 cm -3 = 0.025 of critical density) magnetized with a 10 T axial field. Results show that the deuterium plasma reached a peak electron temperature of 670 ± 140 eV, diagnosed using streaked spectroscopy of an argon dopant. The results demonstrate that plasmas relevant tomore » the preheat stage of MagLIF can be produced at multiple laser facilities, thereby enabling more rapid progress in understanding magnetized preheat. Results are compared with magneto-radiation-hydrodynamics simulations, and plans for future experiments are described.« less

Simulated performance of the optical Thomson scattering diagnostic designed for the National Ignition Facility.

PubMed

Ross, J S; Datte, P; Divol, L; Galbraith, J; Froula, D H; Glenzer, S H; Hatch, B; Katz, J; Kilkenny, J; Landen, O; Manuel, A M; Molander, W; Montgomery, D S; Moody, J D; Swadling, G; Weaver, J

2016-11-01

An optical Thomson scattering diagnostic has been designed for the National Ignition Facility to characterize under-dense plasmas. We report on the design of the system and the expected performance for different target configurations. The diagnostic is designed to spatially and temporally resolve the Thomson scattered light from laser driven targets. The diagnostic will collect scattered light from a 50 × 50 × 200 μm volume. The optical design allows operation with different probe laser wavelengths. A deep-UV probe beam (λ 0 = 210 nm) will be used to Thomson scatter from electron plasma densities of ∼5 × 10 20 cm -3 while a 3ω probe will be used for plasma densities of ∼1 × 10 19 cm -3 . The diagnostic package contains two spectrometers: the first to resolve Thomson scattering from ion acoustic wave fluctuations and the second to resolve scattering from electron plasma wave fluctuations. Expected signal levels relative to background will be presented for typical target configurations (hohlraums and a planar foil).

A correlation between hard gamma-ray sources and cosmic voids along the line of sight

DOE PAGES

Furniss, A.; Sutter, P. M.; Primack, J. R.; ...

2014-11-25

We estimate the galaxy density along lines of sight to hard extragalactic gamma-ray sources by correlating source positions on the sky with a void catalog based on the Sloan Digital Sky Survey (SDSS). Extragalactic gamma-ray sources that are detected at very high energy (VHE; E > 100 GeV) or have been highlighted as VHE-emitting candidates in the Fermi Large Area Telescope hard source catalog (together referred to as “VHE-like” sources) are distributed along underdense lines of sight at the 2.4σ level. There is a less suggestive correlation for the Fermi hard source population (1.7σ). A correlation between 10-500 GeV fluxmore » and underdense fraction along the line of sight for VHE-like and Fermi hard sources is found at 2.4σ and 2.6σ, calculated from the Pearson correlation coefficients of r = 0.57 and 0.47, respectively. The preference for underdense sight lines is not displayed by gamma-ray emitting galaxies within the second Fermi catalog, containing sources detected above 100 MeV, or the SDSS DR7 quasar catalog. We investigate whether this marginal correlation might be a result of lower extragalactic background light (EBL) photon density within the underdense regions and find that, even in the most extreme case of a entirely underdense sight line, the EBL photon density is only 2% less than the nominal EBL density. Translating this into gamma-ray attenuation along the line of sight for a highly attenuated source with opacity τ(E, z) ~ 5, we estimate that the attentuation of gamma-rays decreases no more than 10%. This decrease, although non-neglible, is unable to account for the apparent hard source correlation with underdense lines of sight.« less

Self-focusing and defocusing of Gaussian laser beams in collisional underdense magnetized plasmas with considering the nonlinear ohmic heating and ponderomotive force effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ettehadi Abari, Mehdi; Sedaghat, Mahsa; Shokri, Babak, E-mail: b-shokri@sbu.ac.ir

2015-10-15

The propagation characteristics of a Gaussian laser beam in collisional magnetized plasma are investigated by considering the ponderomotive and ohmic heating nonlinearities. Here, by taking into account the effect of the external magnetic field, the second order differential equation of the dimensionless beam width parameter is solved numerically. Furthermore, the nonlinear dielectric permittivity of the mentioned plasma medium in the paraxial approximation and its dependence on the propagation characteristics of the Gaussian laser pulse is obtained, and its variation in terms of the dimensionless plasma length is analyzed at different initial normalized plasma and cyclotron frequencies. The results show thatmore » the dimensionless beam width parameter is strongly affected by the initial plasma frequency, magnetic strength, and laser pulse intensity. Furthermore, it is found that there exists a certain intensity value below which the laser pulse tends to self focus, while the beam diverges above of this value. In addition, the results confirm that, by increasing the plasma and cyclotron frequencies (plasma density and magnetic strength), the self-focusing effect can occur intensively.« less

Plasma-based beam combiner for very high fluence and energy

DOE PAGES

Kirkwood, R. K.; Turnbull, D. P.; Chapman, T.; ...

2017-10-02

Extreme optical fluences, much beyond the damage threshold of conventional optics, are of interest for a range of high-energy-density physics applications. Nonlinear interactions of multiple beams in plasmas have the potential to produce optics that operate at much higher intensity and fluence than is possible in solids. In inertial confinement fusion experiments indirectly driven with lasers, many beams overlap in the plasma inside a hohlraum, and cross-beam energy transfer by Brillouin scattering has been employed to redistribute energy between laser beams within the target. Here in this paper, we show that in a hot, under-dense plasma the energy of manymore » input beams can be combined into a single well-collimated beam. The emerging beam has an energy of 4 kJ (over 1 ns) that is more than triple that of any incident beam, and a fluence that is more than double. Because the optic produced is plasma, and is diffractive, it is inherently capable of generating higher fluences in a single beam than solid-state refractive or reflective optics.« less

Drive for muscularity and social physique anxiety mediate the perceived ideal physique muscle dysmorphia relationship.

PubMed

Thomas, Adam; Tod, David A; Edwards, Christian J; McGuigan, Michael R

2014-12-01

This study examined the mediating role of drive for muscularity and social physique anxiety (SPA) in the perceived muscular male ideal physique and muscle dysmorphia relationship in weight training men. Men (N = 146, mean ± SD; age, 22.8 ± 5.0 years; weight, 82.0 ± 11.1 kg; height, 1.80 ± 0.07 m; body mass index, 25.1 ± 3.0) who participated in weight training completed validated questionnaires measuring drive for muscularity, SPA, perceived muscular male ideal physique, global muscle dysmorphia, and several characteristics of muscle dysmorphia (exercise dependence, diet manipulation, concerns about size/symmetry, physique protection behavior, and supplementation). Perceived ideal physique was an independent predictor of muscle dysmorphia measures except physique protection (coefficients = 0.113-0.149, p ≤ 0.05). Perceived ideal physique also predicted muscle dysmorphia characteristics (except physique protection and diet) through the indirect drive for muscularity pathway (coefficients = 0.055-0.116, p ≤ 0.05). Perceived ideal physique also predicted size/symmetry concerns and physique protection through the indirect drive for muscularity and SPA pathway (coefficients = 0.080-0.025, p ≤ 0.05). These results extend current research by providing insights into the way correlates of muscle dysmorphia interact to predict the condition. The results also highlight signs (e.g., anxiety about muscularity) that strength and conditioning coaches can use to identify at-risk people who may benefit from being referred for psychological assistance.

VLF wave generation by beating of two HF waves in the ionosphere

NASA Astrophysics Data System (ADS)

Kuo, Spencer; Snyder, Arnold; Kossey, Paul; Chang, Chia-Lie; Labenski, John

2011-05-01

Theory of a beat-wave mechanism for very low frequency (VLF) wave generation in the ionosphere is presented. The VLF current is produced by beating two high power HF waves of slightly different frequencies through the nonlinearity and inhomogeneity of the ionospheric plasma. Theory also shows that the density irregularities can enhance the beat-wave generation. An experiment was conducted by transmitting two high power HF waves of 3.2 MHz and 3.2 MHz + f, where f = 5, 8, 13, and 2.02 kHz, from the HAARP transmitter. In the experiment, the ionosphere was underdense to the O-mode heater, i.e., the heater frequency f0 > foF2, and overdense or slightly underdense to the X-mode heater, i.e., f0 < fxF2 or f0 ≥ fxF2. The radiation intensity increased with the VLF wave frequency, was much stronger with the X-mode heaters, and was not sensitive to the electrojet. The strongest VLF radiation of 13 kHz was generated when the reflection layer of the X-mode heater was just slightly below the foF2 layer and the spread of the O-mode sounding echoes had the largest enhancement, suggesting an optimal setting for beat-wave generation of VLF waves by the HF heaters.

Plasma-based polarizer and waveplate at large laser intensity

NASA Astrophysics Data System (ADS)

Lehmann, G.; Spatschek, K. H.

2018-06-01

A plasma photonic crystal consists of a plasma density grating which is created in underdense plasma by counterpropagating laser beams. When a high-power laser pulse impinges the crystal, it might be reflected or transmitted. So far only one type of pulse polarization, namely the so-called s wave (or TE mode) was investigated (when the electric field vector is perpendicular to the plane of incidence). Here, when investigating also so-called p waves (or TM modes, where the magnetic field vector is perpendicular to the plane of incidence), it is detected that the transmission and reflection properties of the plasma photonic crystal depend on polarization. A simple analytic model of the crystal allows one to make precise predictions. The first conclusion is that in some operational regime the crystal can act as a plasma polarizer for high-intensity laser pulses. Also, differences in phase velocities for grazing incidence between s and p polarization are found. Thus, secondly, the crystal can be utilized as a waveplate, e.g., transforming linearly polarized laser light into circular polarization. All these processes extend to laser intensities beyond the damage intensities of so far used solid state devices.

CONFERENCE DESCRIPTION Theory of Fusion Plasmas: Varenna-Lausanne International Workshop

NASA Astrophysics Data System (ADS)

Garbet, X.; Sauter, O.

2010-12-01

The Joint Varenna-Lausanne international workshop on Theory of Fusion Plasmas takes place every other year in a place particularly favourable for informal and in-depth discussions. Invited and contributed papers present state-of-the-art research in theoretical plasma physics, covering all domains relevant to fusion plasmas. This workshop always welcomes a fruitful mix of experienced researchers and students, to allow a better understanding of the key theoretical physics models and applications. Theoretical issues related to burning plasmas Anomalous Transport (Turbulence, Coherent Structures, Microinstabilities) RF Heating and Current Drive Macroinstabilities Plasma-Edge Physics and Divertors Fast particles instabilities Further details: http://Varenna-Lausanne.epfl.ch The conference is organized by: Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne, Association EURATOM - Confédération Suisse 'Piero Caldirola' International Centre for the Promotion of Science and International School of Plasma Physics Istituto di Fisica del Plasma del CNR, Milano Editors: X Garbet (CEA, Cadarache, France) and O Sauter (CRPP-EPFL, Lausanne, Switzerland)

Anomalous inverse bremsstrahlung heating of laser-driven plasmas

NASA Astrophysics Data System (ADS)

Kundu, Mrityunjay

2016-05-01

Absorption of laser light in plasma via electron-ion collision (inverse bremsstrahlung) is known to decrease with the laser intensity as I 0 -3/2 or with the electron temperature as T e -3/2 where Coulomb logarithm ln Λ = 0.5ln(1 + k 2 min/k 2 max) in the expression of electron-ion collision frequency v ei is assumed to be independent of ponderomotive velocity v 0 = E0/ω which is unjustified. Here k -1 min = v th/max(ω, ω p), and k -1 max = Z/v 2 th are maximum and minimum cut-off distances of the colliding electron from the ion, v th = √T e is its thermal velocity, ω, ω p are laser and plasma frequency. Earlier with a total velocity v = (v 2 0 + v 2 th)1/2 dependent ln Λ(v) it was reported that v ei and corresponding fractional laser absorption (α) initially increases with increasing intensity, reaches a maximum value, and then fall according to the conventional I 0 -3/2 scaling. This anomalous increase in v ei and α may be objected due to an artifact introduced in ln Λ(v) through k-1 min ∝ v. Here we show similar anomalous increase of v ei and α versus I 0 (in the low temperature and under-dense density regime) with quantum and classical kinetic models of v ei without using ln Λ, but a proper choice of the total velocity dependent inverse cut-off length kmax -1 ∝ v 2 (in classical case) or kmax ∝ v (in quantum case). For a given I 0 < 5 × 1014Wcm-2, v ei versus T e also exhibits so far unnoticed identical anomalous increase as v ei versus Io, even if the conventional k max ∝ v2 th, or k max ∝ v th is chosen. However, for higher T e > 15 eV, anomalous growth of vei and a disappear. The total velocity dependent k max in kinetic models, as proposed here, may explain anomalous increase of a with I 0 measured in some earlier laser-plasma experiments. This work may be important to understand collisional absorption in the under-dense pre-plasma region due to low intensity pre-pulses and amplified spontaneous emission (ASE) pedestal in the context of laser induced inertial confinement fusion.

Confinement of laser plasma expansion with strong external magnetic field

NASA Astrophysics Data System (ADS)

Tang, Hui-bo; Hu, Guang-yue; Liang, Yi-han; Tao, Tao; Wang, Yu-lin; Hu, Peng; Zhao, Bin; Zheng, Jian

2018-05-01

The evolutions of laser ablation plasma, expanding in strong (∼10 T) transverse external magnetic field, were investigated in experiments and simulations. The experimental results show that the magnetic field pressure causes the plasma decelerate and accumulate at the plasma-field interface, and then form a low-density plasma bubble. The saturation size of the plasma bubble has a scaling law on laser energy and magnetic field intensity. Magnetohydrodynamic simulation results support the observation and find that the scaling law (V max ∝ E p /B 2, where V max is the maximum volume of the plasma bubble, E p is the absorbed laser energy, and B is the magnetic field intensity) is effective in a broad laser energy range from several joules to kilo-joules, since the plasma is always in the state of magnetic field frozen while expanding. About 15% absorbed laser energy converts into magnetic field energy stored in compressed and curved magnetic field lines. The duration that the plasma bubble comes to maximum size has another scaling law t max ∝ E p 1/2/B 2. The plasma expanding dynamics in external magnetic field have a similar character with that in underdense gas, which indicates that the external magnetic field may be a feasible approach to replace the gas filled in hohlraum to suppress the wall plasma expansion and mitigate the stimulated scattering process in indirect drive ignition.

Proton acceleration: new developments for focusing and energy selection, and applications in plasma physics

NASA Astrophysics Data System (ADS)

Audebert, P.

2007-11-01

In the last few years, intense research has been conducted on laser-accelerated ion sources and their applications. These sources have exceptional properties, i.e. high brightness and high spectral cut-off, high directionality and laminarity, short burst duration. We have shown that for proton energies >10 MeV, the transverse and longitudinal emittance are respectively <0.004 mm-mrad and <10-4 eV-s, i.e. at least 100-fold and may be as much as 10^4-fold better than conventional accelerators beams. Thanks to these properties, these sources allow for example point-projection radiography with unprecedented resolution. We will show example of such time and space-resolved radiography of fast evolving fields, either of associated with the expansion of a plasma in vacuum [*] or with the propagation of a ICF-relevant laser beam in an underdense plasma. These proton sources also open new opportunities for ion beam generation and control, and could stimulate development of compact ion accelerators for many applications.

Optical spectroscopy using gas-phase femtosecond laser filamentation.

PubMed

Odhner, Johanan; Levis, Robert

2014-01-01

Femtosecond laser filamentation occurs as a dynamic balance between the self-focusing and plasma defocusing of a laser pulse to produce ultrashort radiation as brief as a few optical cycles. This unique source has many properties that make it attractive as a nonlinear optical tool for spectroscopy, such as propagation at high intensities over extended distances, self-shortening, white-light generation, and the formation of an underdense plasma. The plasma channel that constitutes a single filament and whose position in space can be controlled by its input parameters can span meters-long distances, whereas multifilamentation of a laser beam can be sustained up to hundreds of meters in the atmosphere. In this review, we briefly summarize the current understanding and use of laser filaments for spectroscopic investigations of molecules. A theoretical framework of filamentation is presented, along with recent experimental evidence supporting the established understanding of filamentation. Investigations carried out on vibrational and rotational spectroscopy, filament-induced breakdown, fluorescence spectroscopy, and backward lasing are discussed.

Simulated performance of the optical Thomson scattering diagnostic designed for the National Ignition Facility

DOE PAGES

Ross, J. S.; Datte, P.; Divol, L.; ...

2016-07-28

An optical Thomson scattering diagnostic has been designed for the National Ignition Facility to characterize under-dense plasmas. Here, we report on the design of the system and the expected performance for different target configurations. The diagnostic is designed to spatially and temporally resolve the Thomson scattered light from laser driven targets. The diagnostic will collect scattered light from a 50 × 50 × 200 μm volume. The optical design allows operation with different probe laser wavelengths. A deep-UV probe beam (λ 0 = 210 nm) will be used to Thomson scatter from electron plasma densities of ~5 × 10 20more » cm -3 while a 3ω probe will be used for plasma densities of ~1 × 10 19 cm -3. The diagnostic package contains two spectrometers: the first to resolve Thomson scattering from ion acoustic wave fluctuations and the second to resolve scattering from electron plasma wave fluctuations. Expected signal levels relative to background will be presented for typical target configurations (hohlraums and a planar foil).« less

Non-local Lateral electron heat transport from one or more hot spots.

NASA Astrophysics Data System (ADS)

Matte, Jean-Pierre; Alouani-Bibi, Fathallah

2000-10-01

Fokker-Planck simulations of collisional absorption and transport in long scale length, preformed, underdense plasmas heated by intense and narrow laser hot spots, as in certain recent LANL experiments [1], are presented. The temperature profiles compared with those obtained from flux limited or delocalized heat flow models. For the former, the temperature peaks can be matched only if a very low flux limiter is used, and even then, the scale length of the temperature profile is always overestimated. The electron distribution function will be characterized, and compared to the "DLM" shape, exp(-(v/u)^m), [2] and the best fit for m will be compared to older formulas for uniform plasmas [2]. Hydrodynamic effects are also addressed with simulations which include ion motion; both with and without the ponderomotive force. The enhancement of sound velocity due to the "DLM" shape [3] inside the hot spot will be quantified. [1] J.A. Cobble et al., Phys. Plasmas, 7, 323 (2000) [2] J.P. Matte et al., Plasma Phys. and Contr. Fusion, 30, 1665, (1988) [3] B. B. Afeyan et al., PRL 81, 2322 (1998).

Simulated performance of the optical Thomson scattering diagnostic designed for the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ross, J. S., E-mail: ross36@llnl.gov; Datte, P.; Divol, L.

2016-11-15

An optical Thomson scattering diagnostic has been designed for the National Ignition Facility to characterize under-dense plasmas. We report on the design of the system and the expected performance for different target configurations. The diagnostic is designed to spatially and temporally resolve the Thomson scattered light from laser driven targets. The diagnostic will collect scattered light from a 50 × 50 × 200 μm volume. The optical design allows operation with different probe laser wavelengths. A deep-UV probe beam (λ{sub 0} = 210 nm) will be used to Thomson scatter from electron plasma densities of ∼5 × 10{sup 20} cm{supmore » −3} while a 3ω probe will be used for plasma densities of ∼1 × 10{sup 19} cm{sup −3}. The diagnostic package contains two spectrometers: the first to resolve Thomson scattering from ion acoustic wave fluctuations and the second to resolve scattering from electron plasma wave fluctuations. Expected signal levels relative to background will be presented for typical target configurations (hohlraums and a planar foil).« less

Activités physiques libres ou encadrées et condition physique liée à la santé chez des adultes burundais: étude transversale

PubMed Central

Bizimana, Jean Berchmans; Lawani, Mansourou Mohamed; Akplogan, Barnabé; Gaturagi, Charles

2016-01-01

Introduction l’activité physique régulière a un impact positif sur la santé. Cette étude a pour objet de comparer la condition physique liée à la santé des adultes qui s’exercent librement avec celle des adultes bénéficiant d’un encadrement professionnel. Elle tente aussi d’établir une relation entre le niveau d’activité physique et les paramètres de la condition liée à la santé. Méthodes nous avons évalué le niveau d’activité physique et les paramètres de la condition physique liée à la santé. Par le test t pour échantillons indépendants, nous avons comparé les moyennes et avons par le calcul du coefficient de corrélation r de Pearson analysé la relation entre le niveau d’activité physique et les paramètres de la condition physique. Résultats des écarts significatifs (p < 0,05) de niveau d’activité physique, de souplesse, de V˙O2max et de la FC de repos ont été enregistrés en faveur du groupe encadré. Le niveau d’activité physique est positivement corrélé (p < 0,05) au V˙O2max et à la force de préhension mais négativement corrélé à la FC de repos et au cholestérol LDL. La prévalence des facteurs de risque cardiovasculaire n’est pas élevée excepté pour le cholestérol HDL. Conclusion les résultats de cette étude montrent que l’activité physique libre est aussi efficace que l’activité physique encadrée dans le maintien des profils lipidique et physiologique favorables à la santé chez l’adulte burundais. Cependant, l’activité physique encadrée apporte des bénéfices supplémentaires pour le V˙O2max, la fréquence cardiaque de repos, la souplesse antérieure et la détente verticale PMID:28203315

The influence of exercise identity and social physique anxiety on exercise dependence.

PubMed

Cook, Brian; Karr, Trisha M; Zunker, Christie; Mitchell, James E; Thompson, Ron; Sherman, Roberta; Erickson, Ann; Cao, Li; Crosby, Ross D

2015-09-01

Previous research has identified exercise identity and social physique anxiety as two independent factors that are associated with exercise dependence. The purpose of our study was to investigate the unique and interactive effect of these two known correlates of exercise dependence in a sample of 1,766 female runners. Regression analyses tested the main effects of exercise identity and social physique anxiety on exercise dependence. An interaction term was calculated to examine the potential moderating effect of social physique anxiety on the exercise identity and exercise dependence relationship. Results indicate a main effect for exercise identity and social physique anxiety on exercise dependence; and the interaction of these factors explained exercise dependence scores beyond the independent effects. Thus, social physique anxiety acted as a moderator in the exercise identity and exercise dependence relationship. Our results indicate that individuals who strongly identify themselves as an exerciser and also endorse a high degree of social physique anxiety may be at risk for developing exercise dependence. Our study supports previous research which has examined factors that may contribute to the development of exercise dependence and also suggests a previously unknown moderating relationship for social physique anxiety on exercise dependence.

Mitigation of hot electrons from laser-plasma instabilities in high-Z, highly ionized plasmas

DOE PAGES

Fein, J. R.; Holloway, J. P.; Trantham, M. R.; ...

2017-03-20

Intense lasers interacting with under-dense plasma can drive laser-plasma instabilities (LPIs) that generate largeamplitude electron plasma waves (EPWs). Suprathermal or “hot” electrons produced in the EPWs are detrimental to inertial confinement fusion (ICF), by reducing capsule implosion efficiency through preheat, and also present an unwanted source of background on x-ray diagnostics. Mitigation of hot electrons was demonstrated in the past by altering plasma conditions near the quarter-critical density, n c/4, with the interpretation of reduced growth of the twoplasmon decay (TPD) instability. Here, we present measurements of hot electrons generated in laser-irradiated planar foils of material ranging from low- tomore » high-Z, where the fraction of laser energy converted to hot electrons, fhot was reduced by a factor of 10 3 going from CH to Au. This correlates with steepening density gradient length-scales that were also measured. Radiation hydrodynamic simulations produced electron density profiles in reasonable agreement with our measurements. According to the simulations, both multi-beam TPD and stimulated Raman scattering were predicted to be above threshold with linear threshold parameters that decreased with increasing Z due to steepening length-scales, as well as enhanced laser absorption and increased EPW collisional and Landau damping.« less

Mitigation of hot electrons from laser-plasma instabilities in high-Z, highly ionized plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fein, J. R.; Holloway, J. P.; Trantham, M. R.

Intense lasers interacting with under-dense plasma can drive laser-plasma instabilities (LPIs) that generate largeamplitude electron plasma waves (EPWs). Suprathermal or “hot” electrons produced in the EPWs are detrimental to inertial confinement fusion (ICF), by reducing capsule implosion efficiency through preheat, and also present an unwanted source of background on x-ray diagnostics. Mitigation of hot electrons was demonstrated in the past by altering plasma conditions near the quarter-critical density, n c/4, with the interpretation of reduced growth of the twoplasmon decay (TPD) instability. Here, we present measurements of hot electrons generated in laser-irradiated planar foils of material ranging from low- tomore » high-Z, where the fraction of laser energy converted to hot electrons, fhot was reduced by a factor of 10 3 going from CH to Au. This correlates with steepening density gradient length-scales that were also measured. Radiation hydrodynamic simulations produced electron density profiles in reasonable agreement with our measurements. According to the simulations, both multi-beam TPD and stimulated Raman scattering were predicted to be above threshold with linear threshold parameters that decreased with increasing Z due to steepening length-scales, as well as enhanced laser absorption and increased EPW collisional and Landau damping.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pluquet, Alain

Cette théetudie les techniques d'identication de l'electron dans l'experience D0 au laboratoire Fermi pres de Chicago Le premier chapitre rappelle quelques unes des motivations physiques de l'experience physique des jets physique electrofaible physique du quark top Le detecteur D0 est decrit en details dans le second chapitre Le troisieme cha pitre etudie les algorithmes didentication de lelectron trigger reconstruction ltres et leurs performances Le quatrieme chapitre est consacre au detecteur a radiation de transition TRD construit par le Departement dAstrophysique Physique des Particules Physique Nucleaire et dInstrumentation Associee de Saclay il presente son principe sa calibration et ses performances Ennmore » le dernier chapitre decrit la methode mise au point pour lanalyse des donnees avec le TRD et illustre son emploi sur quelques exemples jets simulant des electrons recherche du quark top« less

Body self-discrepancies and women's social physique anxiety: the moderating role of the feared body.

PubMed

Woodman, Tim; Steer, Rebecca

2011-05-01

We explored ideal, ought, and feared body image self-discrepancies as predictors of social physique anxiety within Carver, Lawrence, and Scheier's and Woodman and Hemmings' interaction frameworks. One hundred women completed actual, ideal, ought, and feared body self-discrepancy visual analogue scales, the Social Physique Anxiety Scale and the Beck Depression Inventory-II. Moderated hierarchical regression analyses indicated that the relationship between ought body fat discrepancies and social physique anxiety was moderated by proximity to the feared fat self. Specifically, the positive relationship between ought fat discrepancies and social physique anxiety was stronger when women were far from their feared body self. The results highlight the importance of considering the feared self in order to more fully understand the relationship between body image and social physique anxiety. ©2010 The British Psychological Society.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barreira, Alexandre; Bose, Sownak; Li, Baojiu

We study the imprints that theories of gravity beyond GR can leave on the lensing signal around line of sight directions that are predominantly halo-underdense (called troughs) and halo-overdense. To carry out our investigations, we consider the normal branch of DGP gravity, as well as a phenomenological variant thereof that directly modifies the lensing potential. The predictions of these models are obtained with N-body simulation and ray-tracing methods using the ECOSMOG and Ray-Ramses codes. We analyse the stacked lensing convergence profiles around the underdense and overdense lines of sight, which exhibit, respectively, a suppression and a boost w.r.t. the meanmore » in the field of view. The modifications to gravity in these models strengthen the signal w.r.t. ΛCDM in a scale-independent way. We find that the size of this effect is the same for both underdense and overdense lines of sight, which implies that the density field along the overdense directions on the sky is not sufficiently evolved to trigger the suppression effects of the screening mechanism. These results are robust to variations in the minimum halo mass and redshift ranges used to identify the lines of sight, as well as to different line of sight aperture sizes and criteria for their underdensity and overdensity thresholds.« less

The influence of exercise identity and social physique anxiety on exercise dependence

PubMed Central

Cook, Brian; Karr, Trisha M.; Zunker, Christie; Mitchell, James E.; Thompson, Ron; Sherman, Roberta; Erickson, Ann; Cao, Li; Crosby, Ross D.

2015-01-01

Background Previous research has identified exercise identity and social physique anxiety as two independent factors that are associated with exercise dependence. Aims The purpose of our study was to investigate the unique and interactive effect of these two known correlates of exercise dependence in a sample of 1,766 female runners. Methods Regression analyses tested the main effects of exercise identity and social physique anxiety on exercise dependence. An interaction term was calculated to examine the potential moderating effect of social physique anxiety on the exercise identity and exercise dependence relationship. Results Results indicate a main effect for exercise identity and social physique anxiety on exercise dependence; and the interaction of these factors explained exercise dependence scores beyond the independent effects. Thus, social physique anxiety acted as a moderator in the exercise identity and exercise dependence relationship. Discussion Our results indicate that individuals who strongly identify themselves as an exerciser and also endorse a high degree of social physique anxiety may be at risk for developing exercise dependence. Conclusions Our study supports previous research which has examined factors that may contribute to the development of exercise dependence and also suggests a previously unknown moderating relationship for social physique anxiety on exercise dependence. PMID:26551910

Perceived somatotype and stereotypes of physique among Nigerian schoolchildren.

PubMed

Salokun, S O; Toriola, A L

1985-11-01

The influence of perceived somatotype on stereotypes of behavior associated with body build was investigated among 160 male and 140 female Nigerian children in secondary school. In both groups, the perception of subjects' own physiques and discrepancy between their perceived and preferred physiques significantly explained the variance in the character trait scores attributed to body types. In general, the subjects attributed positive character traits to their perceived somatotypes and undesirable traits to the physiques with which they were dissatisfied. Thus, the perception of somatotype and discrepancy between perceived and preferred physique could significantly differentiate the character traits attributed to body build among male and female children.

High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

NASA Astrophysics Data System (ADS)

Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

2018-04-01

High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

The design of the optical Thomson scattering diagnostic for the National Ignition Facility.

PubMed

Datte, P S; Ross, J S; Froula, D H; Daub, K D; Galbraith, J; Glenzer, S; Hatch, B; Katz, J; Kilkenny, J; Landen, O; Manha, D; Manuel, A M; Molander, W; Montgomery, D; Moody, J; Swadling, G F; Weaver, J

2016-11-01

The National Ignition Facility (NIF) is a 192 laser beam facility designed to support the Stockpile Stewardship, High Energy Density and Inertial Confinement Fusion (ICF) programs. We report on the design of an Optical Thomson Scattering (OTS) diagnostic that has the potential to transform the community's understanding of NIF hohlraum physics by providing first principle, local, time-resolved measurements of under-dense plasma conditions. The system design allows operation with different probe laser wavelengths by manual selection of the appropriate beam splitter and gratings before the shot. A deep-UV probe beam (λ 0 -210 nm) will be used to optimize the scattered signal for plasma densities of 5 × 10 20 electrons/cm 3 while a 3ω probe will be used for experiments investigating lower density plasmas of 1 × 10 19 electrons/cm 3 . We report the phase I design of a two phase design strategy. Phase I includes the OTS telescope, spectrometer, and streak camera; these will be used to assess the background levels at NIF. Phase II will include the design and installation of a probe laser.

Plasma Evolution within an Erupting Coronal Cavity

NASA Astrophysics Data System (ADS)

Long, David M.; Harra, Louise K.; Matthews, Sarah A.; Warren, Harry P.; Lee, Kyoung-Sun; Doschek, George A.; Hara, Hirohisa; Jenkins, Jack M.

2018-03-01

Coronal cavities have previously been observed to be associated with long-lived quiescent filaments and are thought to correspond to the associated magnetic flux rope. Although the standard flare model predicts a coronal cavity corresponding to the erupting flux rope, these have only been observed using broadband imaging data, restricting an analysis to the plane-of-sky. We present a unique set of spectroscopic observations of an active region filament seen erupting at the solar limb in the extreme ultraviolet. The cavity erupted and expanded rapidly, with the change in rise phase contemporaneous with an increase in nonthermal electron energy flux of the associated flare. Hot and cool filamentary material was observed to rise with the erupting flux rope, disappearing suddenly as the cavity appeared. Although strongly blueshifted plasma continued to be observed flowing from the apex of the erupting flux rope, this outflow soon ceased. These results indicate that the sudden injection of energy from the flare beneath forced the rapid eruption and expansion of the flux rope, driving strong plasma flows, which resulted in the eruption of an under-dense filamentary flux rope.

Phase-matched second- and third-harmonic generation in plasmas with density ripple

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dahiya, Deepak; Sajal, Vivek; Sharma, A. K.

The generation of second and third harmonics by the interaction of an ultrashort laser pulse with underdense plasma having a density ripple is studied at intensities I{lambda}{sup 2}=10{sup 16}-10{sup 19} W cm{sup -2} {mu}m{sup 2} using fully relativistic two-dimensional particle-in-cell simulations with high spectral resolution. A theoretical model is developed for second- and third-harmonic conversion efficiencies. When the laser is plane polarized in the simulation plane even and odd harmonics are excited in the same polarization as the laser polarization. The highest efficiency of generation of a specific harmonic occurs when the ripple wave vector value k{sub q} satisfies phase-matchingmore » conditions. The efficiency of phase-matched harmonic generation is an order of magnitude higher than the one without phase matching. The efficiency increases rapidly in weak and moderate relativistic regime and tends to saturate in strong relativistic regime. At moderately relativistic intensities and low plasma densities, the simulation and recent experimental results are fairly reproduced by an analytical theory.« less

Electronegative Gas Thruster

NASA Technical Reports Server (NTRS)

Dankanich, John; Polzin, Kurt; Walker, Mitchell

2015-01-01

The project is an international collaboration and academic partnership to mature an innovative electric propulsion thruster concept to Technology Research Level-3 (TRL-3) through direct thrust measurement. The project includes application assessment of the technology ranging from small spacecraft to high power. The Plasma propulsion with Electronegative GASES(PEGASES) basic proof of concept has been matured to TRL-2 by Ane Aanesland of Laboratoire de Physique des Plasma at Ecole Polytechnique. The concept has advantages through eliminating the neutralizer requirement and should yield longer life and lower cost over conventional gridded ion engines. The objective of this research is to validate the proof of concept through the first direct thrust measurements and mature the concept to TRL-3.

Does Body Mass Index Influence Behavioral Regulations, Dispositional Flow and Social Physique Anxiety in Exercise Setting?

PubMed Central

Ersöz, Gözde; Altiparmak, Ersin; Aşçı, F. Hülya

2016-01-01

The purpose of this study was to examine differences in behavioral regulations, dispositional flow, social physique anxiety of exercisers in terms of body mass index (BMI). 782 university students participated in this study. Dispositional Flow State Scale-2, Behavioral Regulations in Exercise Questionnaire-2, Social Physique Anxiety Scale and Physical Activity Stages of Change Questionnaire were administered to participants. After controlling for gender, analysis indicated significant differences in behavioral regulations, dispositional flow and social physique anxiety of exercise participants with regards to BMI. In summary, the findings demonstrate that normal weighted participants exercise for internal reasons while underweighted participants are amotivated for exercise participation. Additionally, participants who are underweight had higher dispositional flow and lower social physique anxiety scores than other BMI classification. Key points Normal weighted participants exercise for internal reasons. Underweighted participants are amotivated for exercise participation. Underweighted participants had higher dispositional flow. Underweighted participants have lower social physique anxiety scores than normal weighted, overweight and obese participants. PMID:27274667

Electron residual energy due to stochastic heating in field-ionized plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khalilzadeh, Elnaz; The Plasma Physics and Fusion Research School, Tehran; Yazdanpanah, Jam, E-mail: jamal.yazdan@gmail.com

2015-11-15

The electron residual energy originated from the stochastic heating in under-dense field-ionized plasma is investigated here. Initially, the optical response of plasma is modeled by using two counter-propagating electromagnetic waves. In this case, the solution of motion equation of a single electron indicates that by including the ionization, the electron with higher residual energy compared with that without ionization could be obtained. In agreement with chaotic nature of the motion, it is found that the electron residual energy will be significantly changed by applying a minor change in the initial conditions. Extensive kinetic 1D-3V particle-in-cell simulations have been performed inmore » order to resolve full plasma reactions. In this way, two different regimes of plasma behavior are observed by varying the pulse length. The results indicate that the amplitude of scattered fields in a proper long pulse length is high enough to act as a second counter-propagating wave and trigger the stochastic electron motion. On the contrary, the analyses of intensity spectrum reveal the fact that the dominant scattering mechanism tends to Thomson rather than Raman scattering by increasing the pulse length. A covariant formalism is used to describe the plasma heating so that it enables us to measure electron temperature inside and outside of the pulse region.« less

Social Physique Anxiety, Obligation to Exercise, and Exercise Choices among College Students

ERIC Educational Resources Information Center

Chu, Hui-Wen; Bushman, Barbara A.; Woodard, Rebecca J.

2008-01-01

Objective: The authors examined relationships among social physique anxiety, obligation to exercise, and exercise choices. Participants and Methods: College students (N = 337; 200 women, 137 men) volunteered to complete 3 questionnaires: the Social Physique Anxiety Scale (SPAS), Obligatory Exercise Questionnaire (OEQ), and Physical Activity…

Electron Bernstein Wave Emission Studies on the TJ-II Stellarator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caughman, John B; Fernandez, A.; Cappa, A.

2009-01-01

Electron Bernstein Wave (EBW) heating is important for high-beta plasma experiments and will be used for heating over-dense plasmas on TJ-II. TJ-II is a medium sized Heliac operating at CIEMAT in Madrid, whose plasmas are created and heated by ECH via two 300 kW gyrotrons at second harmonic X-mode (53.2 GHz), with additional heating provided by two neutral beam injectors. Theoretical work has shown that the most suitable scheme for launching EBWs in TJ-II is O-X-B mode conversion, which has acceptable heating efficiency for central densities above 1.2 x 1019 m-3.[1] A system based on a 28 GHz-100ms diode gyrotronmore » will be used to deliver 300 kW through a corrugated waveguide. The microwave heating beam will be directed and focused by a steering mirror located inside the vacuum vessel. Prior to the heating experiments, measurement of the thermal EBW emission (EBE) from the plasma is being made to help determine the optimum launch angle for EBW mode conversion, and also to provide an indication of the electron temperature evolution in over-dense plasmas. A dual-polarized quad-ridged broadband horn is used to measure the EBW emission and polarization at 28 GHz. Initial measurements indicate that the emission in under-dense plasmas corresponds to oblique electron cyclotron emission (ECE) and then converts to EBE when the plasma becomes over-dense during neutral beam injection.« less

An accurate and efficient laser-envelope solver for the modeling of laser-plasma accelerators

DOE PAGES

Benedetti, C.; Schroeder, C. B.; Geddes, C. G. R.; ...

2017-10-17

Detailed and reliable numerical modeling of laser-plasma accelerators (LPAs), where a short and intense laser pulse interacts with an underdense plasma over distances of up to a meter, is a formidably challenging task. This is due to the great disparity among the length scales involved in the modeling, ranging from the micron scale of the laser wavelength to the meter scale of the total laser-plasma interaction length. The use of the time-averaged ponderomotive force approximation, where the laser pulse is described by means of its envelope, enables efficient modeling of LPAs by removing the need to model the details ofmore » electron motion at the laser wavelength scale. Furthermore, it allows simulations in cylindrical geometry which captures relevant 3D physics at 2D computational cost. A key element of any code based on the time-averaged ponderomotive force approximation is the laser envelope solver. In this paper we present the accurate and efficient envelope solver used in the code INF & RNO (INtegrated Fluid & paRticle simulatioN cOde). The features of the INF & RNO laser solver enable an accurate description of the laser pulse evolution deep into depletion even at a reasonably low resolution, resulting in significant computational speed-ups.« less

An accurate and efficient laser-envelope solver for the modeling of laser-plasma accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benedetti, C.; Schroeder, C. B.; Geddes, C. G. R.

Detailed and reliable numerical modeling of laser-plasma accelerators (LPAs), where a short and intense laser pulse interacts with an underdense plasma over distances of up to a meter, is a formidably challenging task. This is due to the great disparity among the length scales involved in the modeling, ranging from the micron scale of the laser wavelength to the meter scale of the total laser-plasma interaction length. The use of the time-averaged ponderomotive force approximation, where the laser pulse is described by means of its envelope, enables efficient modeling of LPAs by removing the need to model the details ofmore » electron motion at the laser wavelength scale. Furthermore, it allows simulations in cylindrical geometry which captures relevant 3D physics at 2D computational cost. A key element of any code based on the time-averaged ponderomotive force approximation is the laser envelope solver. In this paper we present the accurate and efficient envelope solver used in the code INF & RNO (INtegrated Fluid & paRticle simulatioN cOde). The features of the INF & RNO laser solver enable an accurate description of the laser pulse evolution deep into depletion even at a reasonably low resolution, resulting in significant computational speed-ups.« less

An accurate and efficient laser-envelope solver for the modeling of laser-plasma accelerators

NASA Astrophysics Data System (ADS)

Benedetti, C.; Schroeder, C. B.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

2018-01-01

Detailed and reliable numerical modeling of laser-plasma accelerators (LPAs), where a short and intense laser pulse interacts with an underdense plasma over distances of up to a meter, is a formidably challenging task. This is due to the great disparity among the length scales involved in the modeling, ranging from the micron scale of the laser wavelength to the meter scale of the total laser-plasma interaction length. The use of the time-averaged ponderomotive force approximation, where the laser pulse is described by means of its envelope, enables efficient modeling of LPAs by removing the need to model the details of electron motion at the laser wavelength scale. Furthermore, it allows simulations in cylindrical geometry which captures relevant 3D physics at 2D computational cost. A key element of any code based on the time-averaged ponderomotive force approximation is the laser envelope solver. In this paper we present the accurate and efficient envelope solver used in the code INF&RNO (INtegrated Fluid & paRticle simulatioN cOde). The features of the INF&RNO laser solver enable an accurate description of the laser pulse evolution deep into depletion even at a reasonably low resolution, resulting in significant computational speed-ups.

X-ray Synchrotron Radiation in a Plasma Wiggler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Shuoquin; /UCLA /SLAC, SSRL

2005-09-27

A relativistic electron beam can radiate due to its betatron motion inside an ion channel. The ion channel is induced by the electron bunch as it propagates through an underdense plasma. In the theory section of this thesis the formation of the ion channel, the trajectories of beam electrons inside the ion channel, the radiation power and the radiation spectrum of the spontaneous emission are studied. The comparison between different plasma wiggler schemes is made. The difficulties in realizing stimulated emission as the beam traverses the ion channel are investigated, with particular emphasis on the bunching mechanism, which is importantmore » for the ion channel free electron laser. This thesis reports an experiment conducted at the Stanford Linear Accelerator Center (SLAC) to measure the betatron X-ray radiations for the first time. They first describe the construction and characterization of the lithium plasma source. In the experiment, the transverse oscillations of the SLAC 28.5 GeV electron beam traversing through a 1.4 meter long lithium plasma source are clearly seen. These oscillations lead to a quadratic density dependence of the spontaneously emitted betatron X-ray radiation. The divergence angle of the X-ray radiation is measured. The absolute photon yield and the spectral brightness at 14.2 KeV photon energy are estimated and seen to be in reasonable agreement with theory.« less

Three dimensional structure of the magnetic field generated by counter-streaming electron beams

NASA Astrophysics Data System (ADS)

Califano, F.; Pegoraro, F.; Bulanov, S.

2002-11-01

The Weibel instability is an electromagnetic plasma mode that can transform the thermal energy of an anisotropic plasma into magnetic field energy. In the field of laser plasma interactions a similar type of instability has been considered as the cause of the current filamentation and magnetic field generation that occurs in the wake of an ultra-intense, ultra-short laser pulse propagating in an underdense plasma [1]. Recently, much attention has been paid to this instability also in overdense plasma regimes [2] where current filaments are observed in large scale 3D PIC numerical simulations and large ordered magnetic fields can contribute to the energetic electron transport. Here we study the evolution of this instability in a 3D fluid (relativistic) regime, in the case of a plasma where the anisotropy is due two counter-streaming electron beams, with the aim of understanding the typical magnetic structures that are to be expected as a consequence of the development of this instability. We present the initial phase of the nonlinear instability regime, where kinetic effects are not yet dominant, and stress the differences with respect to the 2D results where the system is supposed to remain homogeneous along the beam direction. The applicability of these results to the interpretation of the simulation results in the overdense laser-plasma regime is also discussed. [1] G.A.Askar'an, S.V. Bulanov, F. Pegoraro, A.M. Pukhov, Physics Reports 21, 835 (1995) [2] M. Honda, J. Meyer-ter-Vehn, and A. Pukhov, Plasma Phys. Rev. Lett. 85, 2128 (2000)

Feasibility study for using an extended three-wave model to simulate plasma-based backward Raman amplification in one spatial dimension

NASA Astrophysics Data System (ADS)

Wang, T.-L.; Michta, D.; Lindberg, R. R.; Charman, A. E.; Martins, S. F.; Wurtele, J. S.

2009-12-01

Results are reported of a one-dimensional simulation study comparing the modeling capability of a recently formulated extended three-wave model [R. R. Lindberg, A. E. Charman, and J. S. Wurtele, Phys. Plasmas 14, 122103 (2007); Phys. Plasmas 15, 055911 (2008)] to that of a particle-in-cell (PIC) code, as well as to a more conventional three-wave model, in the context of the plasma-based backward Raman amplification (PBRA) [G. Shvets, N. J. Fisch, A. Pukhov et al., Phys. Rev. Lett. 81, 4879 (1998); V. M. Malkin, G. Shvets, and N. J. Fisch, Phys. Rev. Lett. 82, 4448 (1999); Phys. Rev. Lett. 84, 1208 (2000)]. The extended three-wave model performs essentially as well as or better than a conventional three-wave description in all temperature regimes tested, and significantly better at the higher temperatures studied, while the computational savings afforded by the extended three-wave model make it a potentially attractive tool that can be used prior to or in conjunction with PIC simulations to model the kinetic effects of PBRA for nonrelativistic laser pulses interacting with underdense thermal plasmas. Very fast but reasonably accurate at moderate plasma temperatures, this model may be used to perform wide-ranging parameter scans or other exploratory analyses quickly and efficiently, in order to guide subsequent simulation via more accurate if intensive PIC techniques or other algorithms approximating the full Vlasov-Maxwell equations.

Effect of Sports Club Activities on the Physique and Physical Fitness of Young Japanese Males

ERIC Educational Resources Information Center

Noguchi, Takanori; Demura, Shin-ichi; Shimada, Shigeru; Kobayashi, Hidetsugu; Yamaji, Shunsuke; Yamada, Takayoshi

2013-01-01

This study compared the growth and development of the physique and physical fitness of young Japanese males who belong to sports clubs and those who did not based on longitudinal data obtained over four years. Physique and physical fitness tests were administered to 253 healthy male technical college students four times from the 9 to 12 grade.…

Supernovae as probes of cosmic parameters: estimating the bias from under-dense lines of sight

DOE Office of Scientific and Technical Information (OSTI.GOV)

Busti, V.C.; Clarkson, C.; Holanda, R.F.L., E-mail: vinicius.busti@uct.ac.za, E-mail: holanda@uepb.edu.br, E-mail: chris.clarkson@uct.ac.za

2013-11-01

Correctly interpreting observations of sources such as type Ia supernovae (SNe Ia) require knowledge of the power spectrum of matter on AU scales — which is very hard to model accurately. Because under-dense regions account for much of the volume of the universe, light from a typical source probes a mean density significantly below the cosmic mean. The relative sparsity of sources implies that there could be a significant bias when inferring distances of SNe Ia, and consequently a bias in cosmological parameter estimation. While the weak lensing approximation should in principle give the correct prediction for this, linear perturbationmore » theory predicts an effectively infinite variance in the convergence for ultra-narrow beams. We attempt to quantify the effect typically under-dense lines of sight might have in parameter estimation by considering three alternative methods for estimating distances, in addition to the usual weak lensing approximation. We find in each case this not only increases the errors in the inferred density parameters, but also introduces a bias in the posterior value.« less

Social physique anxiety, obligation to exercise, and exercise choices among college students.

PubMed

Chu, Hui-Wen; Bushman, Barbara A; Woodard, Rebecca J

2008-01-01

The authors examined relationships among social physique anxiety, obligation to exercise, and exercise choices. College students (N = 337; 200 women, 137 men) volunteered to complete 3 questionnaires: the Social Physique Anxiety Scale (SPAS), Obligatory Exercise Questionnaire (OEQ), and Physical Activity Specification Survey (PASS). On the SPAS, men (M score = 31.9 +/- 8.8) differed from women (M score = 37.3 +/- 8.3; p = .001). Men (M score = 43.0 +/- 9.9) and women (M score = 43.0 +/- 9.6) responded similarly (p = .94) on the OEQ. There was no interaction between sex and exercise level on the SPAS or OEQ. When separated by low, medium, and high SPAS scores, neither OEQ nor exercise scores differed. Obligation to exercise appears to be similar for both sexes. Women, however, appear to have higher levels of anxiety regarding how others evaluate their physique than do men. The combination of level of activity and sex do not appear to be associated with social physique anxiety or obligation to exercise.

Examining social physique anxiety and disordered eating in college women. The roles of social comparison and body surveillance.

PubMed

Fitzsimmons-Craft, Ellen E; Harney, Megan B; Brownstone, Lisa M; Higgins, M K; Bardone-Cone, Anna M

2012-12-01

Social physique anxiety has been found to be associated with disordered eating. However, what is not yet known is what behaviors college women may engage in that strengthen this relation. In the current study, we examined two possible moderating factors, social comparison and body surveillance. We examined whether these moderators might also generalize to trait anxiety, as well. Participants were 265 women attending a Southeastern university. Social comparison (both general and appearance-related) and body surveillance were tested as moderators of the relation between social physique anxiety and disordered eating. Results indicated that general social comparison, appearance-related social comparison, and body surveillance significantly moderated this relation. Individuals who were high in social physique anxiety and who reported high levels of general or appearance-related social comparison or body surveillance reported much higher levels of disordered eating than those with high social physique anxiety and low levels of these behaviors. Results indicated that only the trait anxiety×body surveillance interaction was significant in identifying elevated disordered eating. Results provide information regarding who may experience high levels of disordered eating in association with social physique anxiety, which has clinical implications including the conceptualization of social comparison and body surveillance as safety behaviors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Controlling of the electromagnetic solitary waves generation in the wake of a two-color laser

NASA Astrophysics Data System (ADS)

Pan, K. Q.; Li, S. W.; Guo, L.; Yang, D.; Li, Z. C.; Zheng, C. Y.; Jiang, S. E.; Zhang, B. H.; He, X. T.

2018-05-01

Electromagnetic solitary waves generated by a two-color laser interaction with an underdense plasma are investigated. It is shown that, when the former wave packet of the two-color laser is intense enough, it will excite nonlinear wakefields and generate electron density cavities. The latter wave packets will beat with the nonlinear wakefield and generate both high-frequency and low-frequency components. When the peak density of the cavities exceeds the critical density of the low-frequency component, this part of the electromagnetic field will be trapped to generate electromagnetic solitary waves. By changing the laser and plasma parameters, we can control the wakefield generation, which will also control the generation of the solitary waves. One-dimensional particle-in-cell simulations are performed to prove the controlling of the solitary waves. The simulation results also show that solitary waves generated by higher laser intensities will become moving solitary waves. The two-dimensional particle-in-cell also shows the generation of the solitary waves. In the two-dimensional case, solitary waves are distributed in the transverse directions because of the filamentation instability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pirozhkov, A.S.; Kando, M.; Esirkepov, T.Zh.

We propose a new mechanism of high-order harmonic generation during an interaction of a high-intensity laser pulse with underdense plasma. A tightly focused laser pulse creates a cavity in plasma pushing electrons aside and exciting the wake wave and the bow wave. At the joint of the cavity wall and the bow wave boundary, an annular spike of electron density is formed. This spike surrounds the cavity and moves together with the laser pulse. Collective motion of electrons in the spike driven by the laser field generates high-order harmonics. A strong localization of the electron spike, its robustness to oscillationsmore » imposed by the laser field and, consequently, its ability to produce high-order harmonics is explained by catastrophe theory. The proposed mechanism explains the experimental observations of high-order harmonics with the 9 TW J-KAREN laser (JAEA, Japan) and the 120 TW Astra Gemini laser (CLF RAL, UK) [A. S. Pirozhkov, et al., arXiv:1004.4514 (2010); A. S. Pirozhkov et al, AIP Proceedings, this volume]. The theory is corroborated by high-resolution two-and three-dimensional particle-in-cell simulations.« less

Laser propagation and soliton generation in strongly magnetized plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, W.; Li, J. Q.; Kishimoto, Y.

The propagation characteristics of various laser modes with different polarization, as well as the soliton generation in strongly magnetized plasmas are studied numerically through one-dimensional (1D) particle-in-cell (PIC) simulations and analytically by solving the laser wave equation. PIC simulations show that the laser heating efficiency substantially depends on the magnetic field strength, the propagation modes of the laser pulse and their intensities. Generally, large amplitude laser can efficiently heat the plasma with strong magnetic field. Theoretical analyses on the linear propagation of the laser pulse in both under-dense and over-dense magnetized plasmas are well confirmed by the numerical observations. Mostmore » interestingly, it is found that a standing or moving soliton with frequency lower than the laser frequency is generated in certain magnetic field strength and laser intensity range, which can greatly enhance the laser heating efficiency. The range of magnetic field strength for the right-hand circularly polarized (RCP) soliton formation with high and low frequencies is identified by solving the soliton equations including the contribution of ion's motion and the finite temperature effects under the quasi-neutral approximation. In the limit of immobile ions, the RCP soliton tends to be peaked and stronger as the magnetic field increases, while the enhanced soliton becomes broader as the temperature increases. These findings in 1D model are well validated by 2D simulations.« less

Exercise dependence, social physique anxiety, and social support in experienced and inexperienced bodybuilders and weightlifters

PubMed Central

Hurst, R.; Hale, B.; Smith, D.; Collins, D.

2000-01-01

Objectives—To investigate psychological correlates of exercise dependence in experienced and inexperienced bodybuilders and weightlifters. Secondary objectives included measuring social physique anxiety, bodybuilding identity, and social support among bodybuilders and weightlifters. Methods—Thirty five experienced bodybuilders, 31 inexperienced bodybuilders, and 23 weightlifters completed the bodybuilding dependence scale, a bodybuilding version of the athletic identity measurement scale, the social physique anxiety scale, and an adapted version of the social support survey-clinical form. Results—A between subjects multivariate analysis of variance was calculated on the scores of the three groups of lifters for the four questionnaires. Univariate F tests and follow up tests indicated that experienced bodybuilders scored significantly higher than inexperienced bodybuilders and weightlifters on bodybuilding dependence (p<0.001), social identity and exclusivity subscales of bodybuilding identity (p<0.001), and social support scales (p<.001), and significantly lower on social physique anxiety (p<0.001). Conclusion—Experienced bodybuilders exhibit more exercise dependence, show greater social support behaviour, and experience less social physique anxiety than inexperienced bodybuilders and weightlifters. Key Words: bodybuilding; exercise dependence; social physical anxiety; social support; athletic identity PMID:11131230

Using a short-pulse diffraction-limited laser beam to probe filamentation of a random phase plate smoothed beam.

PubMed

Kline, J L; Montgomery, D S; Flippo, K A; Johnson, R P; Rose, H A; Shimada, T; Williams, E A

2008-10-01

A short pulse (few picoseconds) laser probe provides high temporal resolution measurements to elucidate details of fast dynamic phenomena not observable with typical longer laser pulse probes and gated diagnostics. Such a short pulse laser probe (SPLP) has been used to measure filamentation of a random phase plate (RPP) smoothed laser beam in a gas-jet plasma. The plasma index of refraction due to driven density and temperature fluctuations by the RPP beam perturbs the phase front of a SPLP propagating at a 90 degree angle with respect to the RPP interaction beam. The density and temperature fluctuations are quasistatic on the time scale of the SPLP (approximately 2 ps). The transmitted near-field intensity distribution from the SPLP provides a measure of the phase front perturbation. At low plasma densities, the transmitted intensity pattern is asymmetric with striations across the entire probe beam in the direction of the RPP smoothed beam. As the plasma density increases, the striations break up into smaller sizes along the direction of the RPP beam propagation. The breakup of the intensity pattern is consistent with self-focusing of the RPP smoothed interaction beam. Simulations of the experiment using the wave propagation code, PF3D, are in qualitative agreement demonstrating that the asymmetric striations can be attributed to the RPP driven density fluctuations. Quantification of the beam breakup measured by the transmitted SPLP could lead to a new method for measuring self-focusing of lasers in underdense plasmas.

The Social Physique Anxiety Scale: construct validity in adolescent females.

PubMed

McAuley, E; Burman, G

1993-09-01

Hart, Leary, and Rejeski have developed the Social Physique Anxiety Scale (SPA), a measure of the anxiety experienced in response to having one's physique evaluated by other people. The present study cross-validated the psychometric properties of this measure in a sample (N = 236) of adolescent competitive female gymnasts. Employing structural equation modeling, the proposed unidimensional factor structure of the SPA was supported, although some questions regarding the robustness of the fit are raised. Construct validity was demonstrated by significant inverse relationships between aspects of physical efficacy (perceived physical ability and physical self-presentation confidence) and degree of social physique anxiety. These findings are discussed in terms of possible alternative factor structures and integration of social anxiety and other psychosocial constructs to better understand physical activity behavior.

CDPP Tools in the IMPEx infrastructure

NASA Astrophysics Data System (ADS)

Gangloff, Michel; Génot, Vincent; Bourrel, Nataliya; Hess, Sébastien; Khodachenko, Maxim; Modolo, Ronan; Kallio, Esa; Alexeev, Igor; Al-Ubaidi, Tarek; Cecconi, Baptiste; André, Nicolas; Budnik, Elena; Bouchemit, Myriam; Dufourg, Nicolas; Beigbeder, Laurent

2014-05-01

The CDPP (Centre de Données de la Physique des Plasmas, http://cdpp.eu/), the French data center for plasma physics, is engaged for more than a decade in the archiving and dissemination of plasma data products from space missions and ground observatories. Besides these activities, the CDPP developed services like AMDA (http://amda.cdpp.eu/) which enables in depth analysis of large amount of data through dedicated functionalities such as: visualization, conditional search, cataloguing, and 3DView (http://3dview.cdpp.eu/) which provides immersive visualisations in planetary environments and is further developed to include simulation and observational data. Both tools implement the IMPEx protocol (http://impexfp7.oeaw.ac.at/) to give access to outputs of simulation runs and models in planetary sciences from several providers like LATMOS, FMI , SINP; prototypes have also been built to access some UCLA and CCMC simulations. These tools and their interaction will be presented together with the IMPEx simulation data model (http://impex.latmos.ipsl.fr/tools/DataModel.htm) used for the interface to model databases.

TESTING FOR A LARGE LOCAL VOID BY INVESTIGATING THE NEAR-INFRARED GALAXY LUMINOSITY FUNCTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keenan, R. C.; Wang, W.-H.; Barger, A. J.

2012-08-01

Recent cosmological modeling efforts have shown that a local underdensity on scales of a few hundred Mpc (out to z {approx} 0.1) could produce the apparent acceleration of the expansion of the universe observed via Type Ia supernovae. Several studies of galaxy counts in the near-infrared (NIR) have found that the local universe appears underdense by {approx}25%-50% compared with regions a few hundred Mpc distant. Galaxy counts at low redshifts sample primarily L {approx} L* galaxies. Thus, if the local universe is underdense, then the normalization of the NIR galaxy luminosity function (LF) at z > 0.1 should be highermore » than that measured for z < 0.1. Here we present a highly complete (>90%) spectroscopic sample of 1436 galaxies selected in the H band (1.6 {mu}m) to study the normalization of the NIR LF at 0.1 < z < 0.3 and address the question of whether or not we reside in a large local underdensity. Our survey sample consists of all galaxies brighter than 18th magnitude in the H band drawn from six widely separated fields at high Galactic latitudes, which cover a total of {approx}2 deg{sup 2} on the sky. We find that for the combination of our six fields, the product {phi}*L* at 0.1 < z < 0.3 is {approx}30% higher than that measured at lower redshifts. While our statistical errors in this measurement are on the {approx}10% level, we find the systematics due to cosmic variance may be larger still. We investigate the effects of cosmic variance on our measurement using the COSMOS cone mock catalogs from the Millennium Simulation and recent empirical estimates of cosmic variance. We find that our survey is subject to systematic uncertainties due to cosmic variance at the 15% level (1{sigma}), representing an improvement by a factor of {approx}2 over previous studies in this redshift range. We conclude that observations cannot yet rule out the possibility that the local universe is underdense at z < 0.1. The fields studied in this work have a large amount of publicly available ancillary data and we make available the images and catalogs used here.« less

The stimulated Brillouin scattering during the interaction of picosecond laser pulses with moderate- scale-length plasmas

NASA Astrophysics Data System (ADS)

Gaeris, Andres Claudio

The Stimulated Brillouin Scattering (SBS) instability is studied in moderately short scale-length plasmas. The backscattered and specularly reflected light resulting from the interaction of a pair of high power picosecond duration laser pulses with solid Silicon, Gold and Parylene-N (CH) strip targets was spectrally resolved. The first, weaker laser pulse forms a short scale-length plasma while the second delayed one interacts with the isothermally expanded, underdense region of the plasma. The pulses are generated by the Table Top Terawatt (TTT) laser operating at 1054 nm (infrared) with intensities up to 5.10 16 W/cm2. Single laser pulses only show Lambertian scattering on the target critical surface. Pairs of pulses with high intensity in the second pulse show an additional backscattered, highly blueshifted feature, associated with SBS. Increasing this second pulse intensity even more leads to the appearance of a third feature, even more blueshifted than the second, resulting from the Brillouin sidescattering of the laser pulse reflected on the critical surface. The SBS threshold intensities and enhanced reflectivities for P-polarized light are determined for different plasma density scale-lengths. These measurements agree with the convective thresholds predicted by the SBS theory of Liu, Rosenbluth, and White using plasma profiles simulated by the LILAC code. The spectral position of the Brillouin back- and sidescattered features are determined. The SBS and Doppler shifts are much too small to explain the observed blueshifts. The refractive index shift is of the right magnitude, although more detailed verification is required in the future.

The design of the optical Thomson scattering diagnostic for the National Ignition Facility [The preliminary design of the optical Thomson scattering diagnostic for the National Ignition Facility

DOE PAGES

Datte, P. S.; Ross, J. S.; Froula, D. H.; ...

2016-09-21

Here, the National Ignition Facility (NIF) is a 192 laser beam facility designed to support the Stockpile Stewardship, High Energy Density and Inertial Confinement Fusion (ICF) programs. We report on the design of an Optical Thomson Scattering (OTS) diagnostic that has the potential to transform the community’s understanding of NIF hohlraum physics by providing first principle, local, time-resolved measurements of under-dense plasma conditions. The system design allows operation with different probe laser wavelengths by manual selection of the appropriate beam splitter and gratings before the shot. A deep-UV probe beam (λ 0-210 nm) will be used to optimize the scatteredmore » signal for plasma densities of 5 × 10 20 electrons/cm 3 while a 3ω probe will be used for experiments investigating lower density plasmas of 1 × 10 19 electrons/cm 3. We report the phase I design of a two phase design strategy. Phase I includes the OTS telescope, spectrometer, and streak camera; these will be used to assess the background levels at NIF. Phase II will include the design and installation of a probe laser.« less

The design of the optical Thomson scattering diagnostic for the National Ignition Facility [The preliminary design of the optical Thomson scattering diagnostic for the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Datte, P. S.; Ross, J. S.; Froula, D. H.

Here, the National Ignition Facility (NIF) is a 192 laser beam facility designed to support the Stockpile Stewardship, High Energy Density and Inertial Confinement Fusion (ICF) programs. We report on the design of an Optical Thomson Scattering (OTS) diagnostic that has the potential to transform the community’s understanding of NIF hohlraum physics by providing first principle, local, time-resolved measurements of under-dense plasma conditions. The system design allows operation with different probe laser wavelengths by manual selection of the appropriate beam splitter and gratings before the shot. A deep-UV probe beam (λ 0-210 nm) will be used to optimize the scatteredmore » signal for plasma densities of 5 × 10 20 electrons/cm 3 while a 3ω probe will be used for experiments investigating lower density plasmas of 1 × 10 19 electrons/cm 3. We report the phase I design of a two phase design strategy. Phase I includes the OTS telescope, spectrometer, and streak camera; these will be used to assess the background levels at NIF. Phase II will include the design and installation of a probe laser.« less

Applying Boundary Conditions Using a Time-Dependent Lagrangian for Modeling Laser-Plasma Interactions

NASA Astrophysics Data System (ADS)

Reyes, Jonathan; Shadwick, B. A.

2016-10-01

Modeling the evolution of a short, intense laser pulse propagating through an underdense plasma is of particular interest in the physics of laser-plasma interactions. Numerical models are typically created by first discretizing the equations of motion and then imposing boundary conditions. Using the variational principle of Chen and Sudan, we spatially discretize the Lagrangian density to obtain discrete equations of motion and a discrete energy conservation law which is exactly satisfied regardless of the spatial grid resolution. Modifying the derived equations of motion (e.g., enforcing boundary conditions) generally ruins energy conservation. However, time-dependent terms can be added to the Lagrangian which force the equations of motion to have the desired boundary conditions. Although some foresight is needed to choose these time-dependent terms, this approach provides a mechanism for energy to exit the closed system while allowing the conservation law to account for the loss. An appropriate time discretization scheme is selected based on stability analysis and resolution requirements. We present results using this variational approach in a co-moving coordinate system and compare such results to those using traditional second-order methods. This work was supported by the U. S. Department of Energy under Contract No. DE-SC0008382 and by the National Science Foundation under Contract No. PHY- 1104683.

Thermal conduction study of warm dense aluminum by proton differential heating

NASA Astrophysics Data System (ADS)

Ping, Y.; Kemp, G.; McKelvey, A.; Fernandez-Panella, A.; Shepherd, R.; Collins, G.; Sio, H.; King, J.; Freeman, R.; Hua, R.; McGuffey, C.; Kim, J.; Beg, F.

2016-10-01

A differential heating platform has been developed for thermal conduction study (Ping et al. PoP 2015), where a temperature gradient is induced and subsequent heat flow is probed by time-resolved diagnostics. An experiment using proton differential heating has been carried out at Titan laser for Au/Al targets. Two single-shot time-resolved diagnostics are employed, SOP (streaked optical pyrometry) for surface temperature and FDI (Fourier Domain Interferometry) for surface expansion. Hydrodynamic simulations show that after 15ps, absorption in underdense plasma needs to be taken into account to correctly interpret SOP data. Comparison between simulations with different thermal conductivity models and a set of data with varying target thickness will be presented. This work was performed under DOE contract DE-AC52-07NA27344 with support from OFES Early Career program and LLNL LDRD program.

Media effects of experimental presentation of the ideal physique on eating disorder symptoms: a meta-analysis of laboratory studies.

PubMed

Hausenblas, Heather A; Campbell, Anna; Menzel, Jessie E; Doughty, Jessica; Levine, Michael; Thompson, J Kevin

2013-02-01

Older meta-analyses of the effects of the media's portrayal of the ideal physique have found small effects revealing that exposure to the ideal physique increases body image concerns. These meta-analyses also included correlational, quasi-experimental, and experimental studies, with limited examination of moderators and other relevant outcomes besides body image. We conducted a systematic literature search and identified 33 experimental (i.e., pre and post data for both experimental and control groups) laboratory studies examining the effects of acute exposure to the media's portrayal of the ideal physique on eating disorder symptoms (i.e., body image, positive affect, negative affect, self-esteem, anger, anxiety and depression) and the mechanisms that moderate this effect. Fourteen separate meta-analyses revealed a range of small to moderate effect sizes for change in outcomes from pre to post for both experimental and control groups. Exposure to images of the ideal physique resulted in small effect sizes for increased depression and anger and decreased self-esteem and positive affect. Moderator analyses revealed moderate effect sizes for increased depression and body dissatisfaction among high-risk participants. This meta-analysis makes it clear that media exposure of the ideal physique results in small changes in eating disorder symptoms, particularly with participants at high risk for developing an eating disorder. Further research is needed to examine the longitudinal effects of media exposure of eating disorder symptoms. Copyright © 2012 Elsevier Ltd. All rights reserved.

Les Annales de Réadaptation et de Médecine Physique publication in 2008.

PubMed

Thevenon, A

2009-03-01

In 2008 the European Society of Physical and Rehabilitation Medicine (ESPRM) established a network of European journal and promoted collaboration among the European Physical and Rehabilitation Medicine (PRM) journals. In this connection, the authors present here the articles published in the Annales de Réadaptation et Médecine Physique in 2008. In the same time, the European Journal presents in the Annales de Réadaptation et Médecine Physique its main articles of year 2008. The papers published in the Annales de Réadaptation et Médecine Physique in 2008 were reviewed, classified by topics and discussed. Sixty-four papers are described, with a coverage of all the fields of PRM, from childhood to elderly, from basic science to clinical research, from case studies to epidemiological works. The aim of this paper was to provide physiatrists with some articles of the Annales de Réadaptation et Médecine Physique related to their working condition. Next year, the name of our journal will become Annals of Physical and Rehabilitation Medicine, as most of the articles will be published in French and in English, with the hope that more and more European authors and readers will find it more convenient.

Social Physique Anxiety and Intention to Be Physically Active: A Self-Determination Theory Approach.

PubMed

Sicilia, Álvaro; Sáenz-Alvarez, Piedad; González-Cutre, David; Ferriz, Roberto

2016-12-01

Based on self-determination theory, the purpose of this study was to analyze the relationship between social physique anxiety and intention to be physically active, while taking into account the mediating effects of the basic psychological needs and behavioral regulations in exercise. Having obtained parents' prior consent, 390 students in secondary school (218 boys, 172 girls; M age  = 15.10 years, SD = 1.94 years) completed a self-administered questionnaire during physical education class that assessed the target variables. Preliminary analyses included means, standard deviations, and bivariate correlations among the target variables. Next, a path analysis was performed using the maximum likelihood estimation method with the bootstrapping procedure in the statistical package AMOS 19. Analysis revealed that social physique anxiety negatively predicted intention to be physically active through mediation of the basic psychological needs and the 3 autonomous forms of motivation (i.e., intrinsic motivation, integrated regulation, and identified regulation). The results suggest that social physique anxiety is an internal source of controlling influence that hinders basic psychological need satisfaction and autonomous motivation in exercise, and interventions aimed at reducing social physique anxiety could promote future exercise.

The Physique of Elite Female Artistic Gymnasts: A Systematic Review.

PubMed

Bacciotti, Sarita; Baxter-Jones, Adam; Gaya, Adroaldo; Maia, José

2017-09-01

It has been suggested that successful young gymnasts are a highly select group in terms of the physique. This review summarizes the available literature on elite female gymnasts' anthropometric characteristics, somatotype, body composition and biological maturation. The main aims were to identify: (i) a common physique and (ii) the differences, if any, among competitive/performance levels. A systematic search was conducted online using five different databases. Of 407 putative papers, 17 fulfilled all criteria and were included in the review. Most studies identified similar physiques based on: physical traits (small size and low body mass), a body type (predominance of ecto-mesomorphy), body composition (low fat mass), and maturity status (late skeletal maturity as well as late age-at-menarche). However, there was no consensus as to whether these features predicted competitive performance, or even differentiated between gymnasts within distinctive competitive levels. In conclusion, gymnasts, as a group, have unique pronounced characteristics. These characteristics are likely due to selection for naturally-occurring inherited traits. However, data available for world class competitions were mostly outdated and sample sizes were small. Thus, it was difficult to make any conclusions about whether physiques differed between particular competitive levels.

Niveaux d'étude du cerveau, et sagesse physique

NASA Astrophysics Data System (ADS)

Toulouse, Gérard

1993-02-01

The brain is a complex spatio-temporal affair. Several brain theories propose the definition of three superposed levels of study. But physics, though the experience of condensed matter physics, suggests that it is unwise to enforce onto brain theories a unified hierarchical scheme, the inspiration for which seems to come from the realm of sub-molecular physics. Le cerveau est une affaire spatio-temporelle complexe. Plusieurs théories du cerveau proposent de définir trois niveaux d'études superposés. Mais la physique, à travers l'expérience de la physique de la matière condensée, suggère qu'il n'est pas sage d'imposer sur les théories du cerveau un schéma hiérarchique unifié, dont l'inspiration semble provenir du domaine de la physique sub-moléculaire.

Une vie saine et active : des directives en matière d’activité physique chez les enfants et les adolescents

PubMed Central

Lipnowski, Stan; LeBlanc, Claire MA

2012-01-01

RÉSUMÉ L’épidémie d’obésité juvénile augmente partout dans le monde. Même si les facteurs de risque d’obésité sont multifactoriels, bon nombre sont liés au mode de vie et se prêtent à une intervention. Ces facteurs incluent le comportement sédentaire et la thermogenèse sans activité physique, de même que la fréquence, l’intensité, la quantité et le type d’activité physique. Les dispensateurs de soins de première ligne sont en position idéale pour surveiller le taux d’activité physique des enfants, des adolescents et de leur famille, évaluer les choix liés au mode de vie et offrir des conseils pertinents. Le présent document de principes contient des directives visant à réduire le comportement sédentaire et à accroître le taux d’activité physique au sein de la population pédiatrique. Des recommandations d’activités physiques adaptées au développement et visant les nourrissons, les tout-petits, les enfants d’âge préscolaire, les enfants et les adolescents sont présentées. Des stratégies de promotion d’une vie saine et active sur les scènes locale, municipale, provinciale, territoriale et fédérale sont proposées.

Laser-plasma interactions in direct-drive ignition plasmas

NASA Astrophysics Data System (ADS)

Froula, D. H.; Michel, D. T.; Igumenshchev, I. V.; Hu, S. X.; Yaakobi, B.; Myatt, J. F.; Edgell, D. H.; Follett, R.; Glebov, V. Yu; Goncharov, V. N.; Kessler, T. J.; Maximov, A. V.; Radha, P. B.; Sangster, T. C.; Seka, W.; Short, R. W.; Solodov, A. A.; Sorce, C.; Stoeckl, C.

2012-12-01

Direct-drive ignition is most susceptible to multiple-beam laser-plasma instabilities, as the single-beam intensities are low (Is ˜ 1014 W cm-2) and the electron temperature in the underdense plasma is high (Te ≃ 3.5 keV). Cross-beam energy transfer is driven by multiple laser beams and can significantly reduce the hydrodynamic efficiency in direct-drive experiments on OMEGA (Boehly et al 1997 Opt. Commun. 133 495). Reducing the radii of the laser beams significantly increases the hydrodynamic efficiency at the cost of an increase in the low-mode modulations. Initial 2D hydrodynamic simulations indicate that zooming, transitioning the laser-beam radius prior to the main drive, does not increase low-mode nonuniformities. The combination of zooming and dynamic bandwidth reduction will provide a 30% effective increase in the drive energy on OMEGA direct-drive implosions. It was shown that two-plasmon decay (TPD) can be driven by multiple laser beams and both planar and spherical experiments were performed to study the hot electrons generated by TPD. The fraction of laser energy converted to hot electrons scales with the hot-electron temperature for all geometries and over a wide range of intensities. At ignition-relevant intensities, the fraction of laser energy converted to hot electrons is measured to decrease by an order of magnitude when the ablator material is changed from carbon-hydrogen to aluminum. The TPD results are compared with a multiple-beam linear theory and a nonlinear Zakharov model.

Comparing a Yoga Class with a Resistance Exercise Class: Effects on Body Satisfaction and Social Physique Anxiety in University Women.

PubMed

Gammage, Kimberley L; Drouin, Breanne; Lamarche, Larkin

2016-11-01

The current study compared a single yoga group exercise class and a resistance group exercise class for their effects on state body satisfaction and social physique anxiety in women. A pretest-posttest design was used. Participants (N = 46) completed both a resistance exercise class and yoga class in a counterbalanced order. Measures of body satisfaction and social physique anxiety were completed immediately before and after each class. A 2 (time) × 2 (class type) repeatedmeasures multiple analysis of variance showed a significant overall Time × Class Type interaction (F 2,44 = 5.69, P < .01, η p 2 = .21). There was a significant increase in body satisfaction after the yoga class. After both classes, there was a significant decrease in social physique anxiety, but the magnitude of the change was larger after the yoga class than after the resistance class. Both types of exercise class were associated with improvements in body image, but there were greater improvements after the yoga class. This study provided evidence of the positive effects of yoga for reducing state social physique anxiety and increasing state body satisfaction, adding to correlational evidence suggesting that yoga is particularly beneficial for improving body image-related outcomes in women.

Development of Chinese reference man deformable surface phantom and its application to the influence of physique on electromagnetic dosimetry

NASA Astrophysics Data System (ADS)

Yu, D.; Wang, M.; Liu, Q.

2015-09-01

A reference man is a theoretical individual that represents the average anatomical structure and physiological and metabolic features of a specific group of people and has been widely used in radiation safety research. With the help of an advantage in deformation, the present work proposed a Chinese reference man adult-male polygon-mesh surface phantom based on the Visible Chinese Human segment image dataset by surface rendering and deforming. To investigate the influence of physique on electromagnetic dosimetry in humans, a series of human phantoms with 10th, 50th and 90th body mass index and body circumference percentile physiques for Chinese adult males were further constructed by deforming the Chinese reference man surface phantom. All the surface phantoms were then voxelized to perform electromagnetic field simulation in a frequency range of 20 MHz to 3 GHz using the finite-difference time-domain method and evaluate the whole-body average and organ average specific absorption rate and the ratios of absorbed energy in skin, fat and muscle to the whole body. The results indicate thinner physique leads to higher WBSAR and the volume of subcutaneous fat, the penetration depth of the electromagnetic field in tissues and standing-wave occurrence may be the influence factors of physique on electromagnetic dosimetry.

Reducing parametric backscattering by polarization rotation

DOE PAGES

Barth, Ido; Fisch, Nathaniel J.

2016-10-01

When a laser passes through underdense plasmas, Raman and Brillouin Backscattering can reflect a substantial portion of the incident laser energy. This is a major loss mechanism, for example, in employing lasers in inertial confinement fusion. But, by slow rotation of the incident linear polarization, the overall reflectivity can be reduced significantly. Particle in cell simulations show that, for parameters similar to those of indirect drive fusion experiments, polarization rotation reduces the reflectivity by a factor of 5. A general, fluid-model based analytical estimation for the reflectivity reduction agrees with simulations. However, in identifying the source of the backscatter reduction,more » it is difficult to disentangle the rotating polarization from the frequency separation based approach used to engineer the beam's polarization. Though the backscatter reduction arises similarly to other approaches that employ frequency separation, in the case here, the intensity remains constant in time.« less

Ponderomotive force on solitary structures created during radiation pressure acceleration of thin foils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tripathi, Vipin K.; Sharma, Anamika

2013-05-15

We estimate the ponderomotive force on an expanded inhomogeneous electron density profile, created in the later phase of laser irradiated diamond like ultrathin foil. When ions are uniformly distributed along the plasma slab and electron density obeys the Poisson's equation with space charge potential equal to negative of ponderomotive potential, φ=−φ{sub p}=−(mc{sup 2}/e)(γ−1), where γ=(1+|a|{sup 2}){sup 1/2}, and |a| is the normalized local laser amplitude inside the slab; the net ponderomotive force on the slab per unit area is demonstrated analytically to be equal to radiation pressure force for both overdense and underdense plasmas. In case electron density is takenmore » to be frozen as a Gaussian profile with peak density close to relativistic critical density, the ponderomotive force has non-monotonic spatial variation and sums up on all electrons per unit area to equal radiation pressure force at all laser intensities. The same result is obtained for the case of Gaussian ion density profile and self consistent electron density profile, obeying Poisson's equation with φ=−φ{sub p}.« less

Numerical algorithms for cold-relativistic plasma models in the presence of discontinuties

NASA Astrophysics Data System (ADS)

Hakim, Ammar; Cary, John; Bruhwiler, David; Geddes, Cameron; Leemans, Wim; Esarey, Eric

2006-10-01

A numerical algorithm is presented to solve cold-relativistic electron fluid equations in the presence of sharp gradients and discontinuities. The intended application is to laser wake-field accelerator simulations in which the laser induces accelerating fields thousands of times those achievable in conventional RF accelerators. The relativistic cold-fluid equations are formulated as non-classical system of hyperbolic balance laws. It is shown that the flux Jacobian for this system can not be diagonalized which causes numerical difficulties when developing shock-capturing algorithms. Further, the system is shown to admit generalized delta-shock solutions, first discovered in the context of sticky-particle dynamics (Bouchut, Ser. Adv. Math App. Sci., 22 (1994) pp. 171--190). A new approach, based on relaxation schemes proposed by Jin and Xin (Comm. Pure Appl. Math. 48 (1995) pp. 235--276) and LeVeque and Pelanti (J. Comput. Phys. 172 (2001) pp. 572--591) is developed to solve this system of equations. The method consists of finding an exact solution to a Riemann problem at each cell interface and coupling these to advance the solution in time. Applications to an intense laser propagating in an under-dense plasma are presented.

Investigation of longitudinal proton acceleration in exploded targets irradiated by intense short-pulse laser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gauthier, M.; CEA, DAM, DIF, 91297 Arpajon; Lévy, A.

2014-01-15

It was recently shown that a promising way to accelerate protons in the forward direction to high energies is to use under-dense or near-critical density targets instead of solids. Simulations have revealed that the acceleration process depends on the density gradients of the plasma target. Indeed, under certain conditions, the most energetic protons are predicted to be accelerated by a collisionless shock mechanism that significantly increases their energy. We report here the results of a recent experiment dedicated to the study of longitudinal ion acceleration in partially exploded foils using a high intensity (∼5 × 10{sup 18} W/cm{sup 2}) picosecond laser pulse. Wemore » show that protons accelerated using targets having moderate front and rear plasma gradients (up to ∼8 μm gradient length) exhibit similar maximum proton energy and number compared to proton beams that are produced, in similar laser conditions, from solid targets, in the well-known target normal sheath acceleration regime. Particle-In-Cell simulations, performed in the same conditions as the experiment and consistent with the measurements, allow laying a path for further improvement of this acceleration scheme.« less

Temperature dependence of underdense nanostructure formation in tungsten under helium irradiation

DOE PAGES

Valles, G.; Martin-Bragado, I.; Nordlund, K.; ...

2017-04-19

Recently, tungsten has been found to form a highly underdense nanostructured morphology (“W fuzz”) when bombarded by an intense flux of He ions, but only in the temperature window 900–2000 K. Furthermore, using object kinetic Monte Carlo simulations (pseudo-3D simulations) parameterized from first principles, we show that this temperature dependence can be understood based on He and point defect clustering, cluster growth, and detrapping reactions. At low temperatures (<900 K), fuzz does not grow because almost all He is trapped in very small He-vacancy clusters. At high temperatures (>2300 K), all He is detrapped from clusters, preventing the formation ofmore » the large clusters that lead to fuzz growth in the intermediate temperature range.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galatà, A., E-mail: alessio.galata@lnl.infn.it; Mascali, D.; Neri, L.

A Charge Breeder (CB) is a crucial device of an ISOL facility, allowing post-acceleration of radioactive ions: it accepts an incoming 1+ beam, then multiplying its charge with a highly charged q+ beam as an output. The overall performances of the facility (intensity and attainable final energy) critically depend on the charge breeder optimization. Experimental results collected along the years confirm that the breeding process is still not fully understood and room for improvements still exists: a new numerical approach has been therefore developed and applied to the description of a {sup 85}Rb{sup 1+} beam capture by the plasma ofmore » the 14.5 GHz PHOENIX ECR-based CB, installed at the Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and adopted for the Selective Production of Exotic Species project under construction at Laboratori Nazionali di Legnaro. The results of the numerical simulations, obtained implementing a plasma-target model of increasing accuracy and different values for the plasma potential, will be described along the paper: results very well agree with the theoretical predictions and with the experimental results obtained on the LPSC test bench.« less

Intact capture of hypervelocity projectiles

NASA Technical Reports Server (NTRS)

Tsou, P.

1990-01-01

The ability to capture projectiles intact at hypervelocities opens new applications in science and technology that would either not be possible or would be very costly by other means. This capability has been demonstrated in the laboratory for aluminum projectiles of 1.6 mm diameter, captured at 6 km/s, in one unmelted piece, and retaining up to 95% of the original mass. Furthermore, capture was accomplished passively using microcellular underdense polymer foam. Another advantage of capturing projectiles in an underdense medium is the ability of such a medium to preserve a record of the projectile's original velocity components of speed and direction. A survey of these experimental results is described in terms of a dozen parameters which characterize the amount of capture and the effect on the projectile due to different capture media.

Intact capture of hypervelocity projectiles.

PubMed

Tsou, P

1990-01-01

The ability to capture projectiles intact at hypervelocities opens new applications in science and technology that would either not be possible or would be very costly by other means. This capability has been demonstrated in the laboratory for aluminum projectiles of 1.6 mm diameter, captured at 6 km/s, in one unmelted piece, and retaining up to 95% of the original mass. Furthermore, capture was accomplished passively using microcellular underdense polymer foam. Another advantage of capturing projectiles in an underdense medium is the ability of such a medium to preserve a record of the projectile's original velocity components of speed and direction. A survey of these experimental results is described in terms of a dozen parameters which characterize the amount of capture and the effect on the projectile due to different capture media.

Stress and Thermal Stress Compensation in Quartz SAW Devices

DTIC Science & Technology

1991-08-01

Laboratoire De Physique Et Metrologie Des Oscillateurs E. Bigler, D. Hauden, S. Ballandras OTIC hELECTLE E P19 99f "j APPROVED FOR PUBLIC RELASE, DISTRIBUTION...ORGANIZATION NAME(S) AND ADDRE$S(ES) 8. PERFORMING ORGANIZATION Laboratoire De Physique Et Metrologie Des Oscillateurs REPORT NUMBER Center National de la

Developmental and Contextual Risks of Social Physique Anxiety among Female Athletes

ERIC Educational Resources Information Center

Gay, Jennifer L.; Monsma, Eva V.; Torres-McGehee, Toni M.

2011-01-01

In the present study, we examined developmental and contextual factors that may increase the odds of reporting higher social physique anxiety (SPA) among 404 adolescent athletes 11 to 16 years old. Findings showed older, later maturing athletes past peak height velocity and with greater body mass index (BMI) reported higher SPA. Individual…

Social Physique Anxiety in Adolescence: An Exploration of Influences, Coping Strategies, and Health Behaviors

ERIC Educational Resources Information Center

Sabiston, C. M.; Sedgwick, W. A.; Crocker, P. R. E.; Kowalski, K. C.; Mack, D. E.

2007-01-01

This study explored adolescent females' experiences of social physique anxiety (SPA) and related coping strategies. A final sample of 31 adolescent females ages 13 to 18 years discussed dealing with SPA during individual semistructured interviews. Resultant themes pertaining to the transactional experiences of SPA were coded using content…

An examination of eating attitudes and physical activity levels of Turkish university students with regard to self-presentational concern.

PubMed

Aşçi, F Hülya; Tüzün, Macide; Koca, Canan

2006-11-01

This study aimed to examine eating attitudes and physical activity level of young women and men university students with regard to social physique anxiety level. 482 university students participated in this study voluntarily. "Eating Attitude Test (EAT-40)", "Social Physique Anxiety Scale" and "Physical Activity Assessment Questionnaire" were used to assess the eating attitude, social physique anxiety and physical activity level of participants, respectively. Women and men participants in this study were assigned to high (HSPA) and low (LSPA) social physique anxiety groups with respect to their median scores. Men had favorable eating attitudes and higher physical activity level than women. In addition, participants in the HSPA group had unfavorable eating attitudes and higher physical activity MET values than participants in the LSPA group. On the other hand, groupxgender interaction was only significant for the eating attitudes scores but, not for physical activity level. Women in the HSPA group scored higher on the EAT-40 than men in HSPA and women and men in the LSPA groups.

An Optical Trap for Relativistic Plasma

NASA Astrophysics Data System (ADS)

Zhang, Ping

2002-11-01

Optical traps have achieved remarkable success recently in confining ultra-cold matter.Traps capable of confining ultra-hot matter, or plasma, have also been built for applications such as basic plasma research and thermonuclear fusion. For instance, low-density plasmas with temperature less than 1 keV have been confined with static magnetic fields in Malmberg-Penning traps. Low-density 10-50 keV plasmas are confined in magnetic mirrors and tokamaks. High density plasmas have been trapped in optical traps with kinetic energies up to 10 keV [J. L. Chaloupka and D. D. Meyerhofer, Phys. Rev. Lett. 83, 4538 (1999)]. We present the results of experiment, theory and numerical simulation on an optical trap capable of confining relativistic plasma. A stationary interference grating with submicron spacing is created when two high-power (terawatt) laser pulses of equal wavelength (1-micron) are focused from orthogonal directions to the same point in space and time in high density underdense plasma. Light pressure gradients bunch electrons into sheets located at the minima of the interference pattern. The density of the bunched electrons is found to be up to ten times the background density, which is orders-of-magnitude above that previously reported for other optical traps or plasma waves. The amplitudes and frequencies of multiple satellites in the scattered spectrum also indicate the presence of a highly nonlinear ion wave and an electron temperature about 100 keV. Energy transfer from the stronger beam to the weaker beam is also observed. Potential applications include a test-bed for detailed studies of relativistic nonlinear scattering, a positron source and an electrostatic wiggler. This research is also relevant to fast igniter fusion or ion acceleration experiments, in which laser pulses with intensities comparable to those used in the experiment may also potentially beat [Y. Sentoku, et al., Appl. Phys. B 74, 207215 (2002)]. The details of a specific application, the injection of electrons into laser-driven plasma waves, will also be presented. With crossed beams, the energy of a laser-accelerated electron beam is increased and its emittance is decreased compared with a single beam, potentially paving the way towards an all-optical monoenergetic electron injector.

Examining Combinations of Social Physique Anxiety and Motivation Regulations Using Latent Profile Analysis

ERIC Educational Resources Information Center

Ullrich-French, Sarah; Cox, Anne E.; Cooper, Brittany Rhoades

2016-01-01

Previous research has used cluster analysis to examine how social physique anxiety (SPA) combines with motivation in physical education. This study utilized a more advanced analytic approach, latent profile analysis (LPA), to identify profiles of SPA and motivation regulations. Students in grades 9-12 (N = 298) completed questionnaires at two time…

A Polytomous Item Response Theory Analysis of Social Physique Anxiety Scale

ERIC Educational Resources Information Center

Fletcher, Richard B.; Crocker, Peter

2014-01-01

The present study investigated the social physique anxiety scale's factor structure and item properties using confirmatory factor analysis and item response theory. An additional aim was to identify differences in response patterns between groups (gender). A large sample of high school students aged 11-15 years (N = 1,529) consisting of n =…

Give or Take a Few? Comparing Measured and Self-Reported Height and Weight as Correlates of Social Physique Anxiety

ERIC Educational Resources Information Center

Gay, Jennifer; Monsma, Eva V.; Torres-McGehee, Toni

2009-01-01

Statistically controlling for physical size is common practice, especially in self-perception studies uncovering the etiology of maladaptive behaviors, such as eating disorders. For example, social physique anxiety (SPA)--apprehension about social evaluations while presenting oneself in front of others (Leary, 1992)--is a prominent correlate of…

Physical and Physiological Correlates of Social Physique Anxiety in College Students

ERIC Educational Resources Information Center

Yaman, Çetin

2017-01-01

The purpose of the present study was to explore the relationship among social physique anxiety, physical measures such as body fat and physical self-concept. 367 (226 male and 141 female) college students ranging in age from 21 to 33 participated in the study. Participants were randomly chosen among the healthy students without any metabolic and…

Examining the Moderating Effect of Appearance Impression Motivation on the Relationship between Perceived Physical Appearance and Social Physique Anxiety

ERIC Educational Resources Information Center

Amorose, Anthony J.; Hollembeak, Jill

2005-01-01

Despite the conceptual importance of impression motivation in predicting social anxiety (Leary & Kowalski, 1995; Schlenker & Leary, 1982), no research has tested the link between impression motivation specifically regarding one's physical appearance (appearance impression motivation, or AIM) and social physique anxiety (SPA). The purpose of this…

Social Physique Anxiety and Intention to Be Physically Active: A Self-Determination Theory Approach

ERIC Educational Resources Information Center

Sicilia, Álvaro; Sáenz-Alvarez, Piedad; González-Cutre, David; Ferriz, Roberto

2016-01-01

Purpose: Based on self-determination theory, the purpose of this study was to analyze the relationship between social physique anxiety and intention to be physically active, while taking into account the mediating effects of the basic psychological needs and behavioral regulations in exercise. Method: Having obtained parents' prior consent, 390…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kraljic, David; Sarkar, Subir, E-mail: David.Kraljic@physics.ox.ac.uk, E-mail: Subir.Sarkar@physics.ox.ac.uk

It has been observed [1,2] that the locally measured Hubble parameter converges quickest to the background value and the dipole structure of the velocity field is smallest in the reference frame of the Local Group of galaxies. We study the statistical properties of Lorentz boosts with respect to the Cosmic Microwave Background frame which make the Hubble flow look most uniform around a particular observer. We use a very large N-Body simulation to extract the dependence of the boost velocities on the local environment such as underdensities, overdensities, and bulk flows. We find that the observation [1,2] is not unexpectedmore » if we are located in an underdensity, which is indeed the case for our position in the universe. The amplitude of the measured boost velocity for our location is consistent with the expectation in the standard cosmology.« less

DO NOT FORGET THE FOREST FOR THE TREES: THE STELLAR-MASS HALO-MASS RELATION IN DIFFERENT ENVIRONMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tonnesen, Stephanie; Cen, Renyue, E-mail: stonnes@gmail.com, E-mail: cen@astro.princeton.edu

2015-10-20

The connection between dark matter halos and galactic baryons is often not well constrained nor well resolved in cosmological hydrodynamical simulations. Thus, halo occupation distribution models that assign galaxies to halos based on halo mass are frequently used to interpret clustering observations, even though it is well known that the assembly history of dark matter halos is related to their clustering. In this paper we use high-resolution hydrodynamical cosmological simulations to compare the halo and stellar mass growth of galaxies in a large-scale overdensity to those in a large-scale underdensity (on scales of about 20 Mpc). The simulation reproduces assemblymore » bias, in which halos have earlier formation times in overdense environments than in underdense regions. We find that the ratio of stellar mass to halo mass is larger in overdense regions in central galaxies residing in halos with masses between 10{sup 11} and 10{sup 12.9} M{sub ⊙}. When we force the local density (within 2 Mpc) at z = 0 to be the same for galaxies in the large-scale over- and underdensities, we find the same results. We posit that this difference can be explained by a combination of earlier formation times, more interactions at early times with neighbors, and more filaments feeding galaxies in overdense regions. This result puts the standard practice of assigning stellar mass to halos based only on their mass, rather than considering their larger environment, into question.« less

New Evidence for a Large Local Void From the UKIDSS LAS + SDSS

NASA Astrophysics Data System (ADS)

Keenan, Ryan; Barger, A. J.

2013-01-01

Recent cosmological modeling efforts have shown that a local under-density on scales of a few hundred Mpc (out to z ~ 0.1) could produce the apparent acceleration of the expansion of the universe observed via type Ia supernovae. Several studies of galaxy counts in the near-infrared (NIR) have found that the local universe appears underdense by ~25 - 50% compared with regions a few hundred Mpc distant (e.g. Keenan et al., 2010). An accurate characterization of any such under-density will be important for studies seeking to understand the nature of dark energy. If the space density of galaxies is rising as a function of redshift, then the luminosity density, as measured via the NIR galaxy luminosity function (LF), should be rising as well. In Keenan et al. (2012), we presented a study of the NIR LF at z ~ 0.2 and found that the product φ*L* (the peak of the luminosity density distribution) at z ~ 0.2 is roughly ~ 30% higher than that measured at z ~ 0.05. Here we present the results from a study of the NIR LF derived from galaxies selected from the UKIRT Infrared Deep Sky Large Area Survey (UKIDSS LAS) combined with spectroscopy from the Sloan Digital Sky Survey (SDSS). We confirm the apparent rise in luminosity density found in Keenan et al. (2012) from z = 0.05 to z = 0.1 and provide the first self-consistent measurements of the NIR luminosity density out to z ~ 0.15.

Weak lensing by galaxy troughs in DES Science Verification data

DOE PAGES

Gruen, D.; Friedrich, O.; Amara, A.; ...

2015-11-29

In this study, we measure the weak lensing shear around galaxy troughs, i.e. the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey. Our detection of the shear signal is highly significant (10σ–15σ for the smallest angular scales) for troughs with the redshift range z ϵ [0.2, 0.5] of the projected galaxy field and angular diameters of 10 arcmin…1°. These measurements probe the connection between the galaxy, matter density, and convergence fields. By assuming galaxies are biased tracers ofmore » the matter density with Poissonian noise, we find agreement of our measurements with predictions in a fiducial Λ cold dark matter model. The prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter. Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on all scales. The lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field.« less

Prominence Mass Supply and the Cavity

NASA Technical Reports Server (NTRS)

Schmit, Donald J.; Gibson, S.; Luna, M.; Karpen, J.; Innes, D.

2013-01-01

A prevalent but untested paradigm is often used to describe the prominence-cavity system; the cavity is under-dense because it it evacuated by supplying mass to the condensed prominence. The thermal non-equilibrium (TNE) model of prominence formation offers a theoretical framework to predict the thermodynamic evolutin of the prominence and the surrounding corona. We examine the evidence for a prominence-cavity connection by comparing the TNE model and diagnostics of dynamic extreme ultraviolet (EUV) emission surrounding the prominence, specifically prominence horns. Horns are correlated extensions of prminence plasma and coronal plasma which appear to connect the prominence and cavity. The TNE model predicts that large-scale brightenings will occur in the Solar Dynamics Observatory Atmospheric Imaging Assembly 171 A badpass near he prominence that are associated with the cooling phase of condensation formation. In our simulations, variations in the magnitude of footpoint heating lead to variations in the duration, spatial scale, and temporal offset between emission enhancements in the other EUV bandpasses. While these predictions match well a subset of the horn observations, the range of variations in the observed structures is not captured by the model. We discuss the implications of one-dimensional loop simulations for the three-dimensional time-averaged equilibrium in the prominence and the cavity. Evidence suggests that horns are likely caused by condensing prominence plasma, but the larger question of whether this process produces a density-depleted cavity requires a more tightly constrained model of heating and better knowledge of the associated magnetic structure.

Proton and Ion Acceleration on the Contrast Upgraded Texas Petawatt Laser

NASA Astrophysics Data System (ADS)

McCary, Edward; Roycroft, Rebecca; Jiao, Xuejing; Kupfer, Rotem; Tiwari, Ganesh; Wagner, Craig; Yandow, Andrew; Franke, Philip; Dyer, Gilliss; Gaul, Erhard; Toncian, Toma; Ditmire, Todd; Hegelich, Bjorn; CenterHigh Energy Density Science Team

2016-10-01

Recent upgrades to the Texas Petawatt (TPW) laser system have eliminated pre-pulses and reduced the laser pedestal, resulting in improved laser contrast. Previously unwanted pre-pulses and amplified spontaneous emission (ASE) would ionize targets thinner than 1 micron, leaving an under-dense plasma which was not capable of accelerating ions to high energies. After the upgrade the contrast was drastically improved allowing us to successfully shoot targets as thin as 20 nm without plasma mirrors. We have also observed evidence of relativistic transparency and Break-Out Afterburner (BOA) ion acceleration when shooting ultra-thin, nanometer scale targets. Data taken with a wide angle ion spectrometer (IWASP) showed the characteristic asymmetry of BOA in the plane orthogonal to the laser polarization on thin targets but not on micron scale targets. Thick micron scale targets saw improvement as well; shots on 2 μm thick gold targets saw ions with energies up to 100 MeV, which broke the former record proton energy on the TPW. Switching the focusing optic from an f/3 parabolic mirror to an f/40 spherical mirror showed improvement in the number of low energy protons created, and provided a source for hundreds of picosecond heating of aluminum foils for warm dense matter measurements.

Laser-driven heat-front propagation in foam vs. gas

NASA Astrophysics Data System (ADS)

Pérez, F.; Colvin, J. D.; May, M. J.; Gammon, S. A.; Fournier, K. B.

2014-10-01

A high-energy laser (several kJ, 1015 W/cm2) can propagate inside an underdense plasma over millimeters, along its associated heat front. This creates a large volume of hot plasma (several keV) able to produce bright hard-x-ray sources when a high-Z dopant is included in the material. In the past years, we investigated the behavior of both gases and foams under these circumstances. Their design and predictability relies on the understanding of the heat front propagation. In the case of foams, several studies tried to assess the effect of their micro-structure in altering the laser interaction and the heat front propagation, but no experimental data has shown clear evidence. We present here the design and results of a recent experiment, using the OMEGA laser, where a Ge-doped silica foam was compared to a Ne/Kr gas of very similar characteristics, the only difference between these two materials being their micro-structure to allow for a straightforward determination of its influence. The design of future similar experiments will also be reported. J. Colvin presents theoretical and modeling aspects of this subject in a companion presentation. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract No. DE-AC52-07NA27344.

Quand la réadaptation blesse? Éducateurs victimes de violence

PubMed Central

Geoffrion, Steve; Ouellet, Frédéric

2014-01-01

Cette étude vise à comprendre le phénomène de la violence physique vécue par les éducateurs œuvrant dans dix Centres Jeunesse (CJ) du Québec. Pour ce faire, un sondage de victimisation a été administré à 586 éducateurs en internat. En premier lieu, la prévalence de cette problématique sera établie. Par la suite, les facteurs individuels et environnementaux prédisposant aux agressions physiques seront identifiés. Des édu-cateurs sondés, 53,9 % rapportent avoir été victimes de violence physique au cours de la dernière année. Sur le plan individuel, être affecté par les manifestations agressives des clients et la fréquence des violences psychologiques subies augmentent les risques de victimisation physique. Quant au contexte, l’âge de la clientèle et le motif de l’interven-tion (basé sur la loi justifiant le placement) auprès de l’enfant ou de l’adolescent influencent l’occurrence des actes violents dirigés contre les éducateurs. Nos analyses montrent également que les violences physiques dont sont victimes les éducateurs affectent autant l’individu que l’institution. L’identification de facteurs permettant de prédire les risques de victimisation pourrait notamment servir à orienter les programmes de prévention de la violence dans les CJ, mais aussi à cibler les éducateurs les plus à risque afin de leur fournir un soutien adapté. PMID:24976673

Social Physique Anxiety and Pressure to Be Thin in Adolescent Ballet Dancers, Rhythmic Gymnastics and Swimming Athletes

ERIC Educational Resources Information Center

Kosmidou, Evdoxia; Giannitsopoulou, Evgenia; Moysidou, Dimitra

2017-01-01

Participation in sports may influence negative body image and Social Physique Anxiety (SPA) as there is pressure by significant others to have a certain body image. The aim of the present study was to examine possible differences in SPA and perceived pressure to be thin between female preadolescent and adolescent ballet dancers, rhythmic…

Frequency Upconversion and Parametric Surface Instabilities in Microwave Plasma Interactions.

NASA Astrophysics Data System (ADS)

Rappaport, Harold Lee

In this thesis the interaction of radiation with plasmas whose density profiles are nearly step functions of space and/or time are studied. The wavelengths of radiation discussed are large compared with plasma density gradient scale lengths. The frequency spectra are evaluated and the energy balance investigated for the transmitted and reflected transient electromagnetic waves that are generated when a monochromatic source drives a finite width plasma in which a temporal step increase in density occurs. Transmission resonances associated with the abrupt boundaries manifest themselves as previously unreported multiple frequency peaks in the transmitted electromagnetic spectrum. A tunneling effect is described in which a burst of energy is transmitted from the plasma immediately following a temporal density transition. Stability of an abruptly bounded plasma, one for which the incident radiation wavelength is large compared with the plasma density gradient scale length, is investigated for both s and p polarized radiation types. For s-polarized radiation a new formalism is introduced in which pump induced perturbations are expressed as an explicit superposition of linear and non-linear plasma half-space modes. Results for a particular regime and a summary of relevant literature is presented. We conclude that when s-polarized radiation acts alone on an abrupt diffusely bounded underdense plasma stimulated excitation of electron surface modes is suppressed. For p-polarized radiation the recently proposed Lagrangian Frame Two-Plasmon Decay mode (LFTPD) ^dag is investigated in the regime in which the instability is not resonantly coupled to surface waves propagating along the boundary region. In this case, spatially dependent growth rate profiles and spatially dependent transit layer magnetic fields are reported. The regime is of interest because we have found that when the perturbation wavenumber parallel to the boundary is less than the pump frequency divided by twice the speed of light, energy radiates from the boundary region and these emissions can serve as an experimental signature for this mode. The theory of surface wave linear mode conversion is reviewed with special attention paid to power flow and energy conservation in this system. ftn^ dagYu. M. Aliev and G. Brodin, Phys. Rev. A 42, 2374 (1990).

An Examination of Motivational Regulations, Dispositional Flow and Social Physique Anxiety among College Students for Exercise: A Self-Determination Theory Approach

ERIC Educational Resources Information Center

Ersöz, Gözde

2016-01-01

Based on self-determination theory (SDT), the main goal of this study is to analyze dispositional flow and social physique anxiety (SPA) that could be predicted by gender, BMI and motivational regulations and to examine motivational regulations, dispositional flow and SPA of college students in terms of stage of change for exercise. Participants…

Human Factors Aspects of Aircraft Accidents

DTIC Science & Technology

1982-10-01

preexistante (incapacite soudaine ou non en vo_l) La plus dangereuse (en particulier dans les phases decollage et atterrissage) est l’in- capacite... soudaine . Elle peut 6tre mortelle - dans ce caa, generalement eardiaque - ou sa traduire par des troubles psychiques - d’un developpement brutal et...done conduire a une lncapacite plus ou moins soudaine en vol. pefaillances physiques accidentelles Kors les defaillances physiques classiques

Caracterisation Physique des Sols Camp Militaire de Petawawa (Physical Characterization of the Soil in Military Camp of Petawawa).

DTIC Science & Technology

1979-10-01

AD-AO95 392 DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO) FI6 8/13 CARACTERISATION PHY SI QUE DES SOLS CAMP MILITAIRE DE PETAWAWA (P--ETC(U) OCT 79...defense nationale 2b, GROUP Ottawa, Ontario -KIA-04----- , I D )kI1,vlt Nr Ti fti CARACTERISATION PHYSIQUE DES SOLS, BASE DES FORCES CANADIENNES PETAWAAA I

Examining the Stability of the 7-Item Social Physique Anxiety Scale Using a Test-Retest Method

ERIC Educational Resources Information Center

Scott, Lisa A.; Burke, Kevin L.; Joyner, A. Barry; Brand, Jennifer S.

2004-01-01

This study examined the stability of the 7-item Social Physique Anxiety Scale (SPAS-7) using a test-retest method. Collegiate, undergraduate (N = 201) students completed two administrations of the SPAS-7, with a 14-day separation between the administrations. The scale was administered either at the beginning or end of the physical activity class.…

Experimental demonstration of laser imprint reduction using underdense foams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delorme, B.; Casner, A.; CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence

2016-04-15

Reducing the detrimental effect of the Rayleigh-Taylor (RT) instability on the target performance is a critical challenge. In this purpose, the use of targets coated with low density foams is a promising approach to reduce the laser imprint. This article presents results of ablative RT instability growth measurements, performed on the OMEGA laser facility in direct-drive for plastic foils coated with underdense foams. The laser beam smoothing is explained by the parametric instabilities developing in the foam and reducing the laser imprint on the plastic (CH) foil. The initial perturbation pre-imposed by the means of a specific phase plate wasmore » shown to be smoothed using different foam characteristics. Numerical simulations of the laser beam smoothing in the foam and of the RT growth are performed with a suite of paraxial electromagnetic and radiation hydrodynamic codes. They confirmed the foam smoothing effect in the experimental conditions.« less

Specular Reflectivity and Hot-Electron Generation in High-Contrast Relativistic Laser-Plasma Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kemp, Gregory Elijah

2013-01-01

Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the costmore » of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic laser-plasma interactions.« less

Influence of Xe and Kr impurities on x-ray yield from debris-free plasma x-ray sources with an Ar supersonic gas jet irradiated by femtosecond near-infrared-wavelength laser pulses

NASA Astrophysics Data System (ADS)

Kantsyrev, V. L.; Schultz, K. A.; Shlyaptseva, V. V.; Petrov, G. M.; Safronova, A. S.; Petkov, E. E.; Moschella, J. J.; Shrestha, I.; Cline, W.; Wiewior, P.; Chalyy, O.

2016-11-01

Many aspects of physical phenomena occurring when an intense laser pulse with subpicosecond duration and an intensity of 1018-1019W /cm2 heats an underdense plasma in a supersonic clustered gas jet are studied to determine the relative contribution of thermal and nonthermal processes to soft- and hard-x-ray emission from debris-free plasmas. Experiments were performed at the University of Nevada, Reno (UNR) Leopard laser operated with a 15-J, 350-fs pulse and different pulse contrasts (107 or 105). The supersonic linear (elongated) nozzle generated Xe cluster-monomer gas jets as well as jets with Kr-Ar or Xe-Kr-Ar mixtures with densities of 1018-1019cm-3 . Prior to laser heating experiments, all jets were probed with optical interferometry and Rayleigh scattering to measure jet density and cluster distribution parameters. The supersonic linear jet provides the capability to study the anisotropy of x-ray yield from laser plasma and also laser beam self-focusing in plasma, which leads to efficient x-ray generation. Plasma diagnostics included x-ray diodes, pinhole cameras, and spectrometers. Jet signatures of x-ray emission from pure Xe gas, as well as from a mixture with Ar and Kr, was found to be very different. The most intense x-ray emission in the 1-9 KeV spectral region was observed from gas mixtures rather than pure Xe. Also, this x-ray emission was strongly anisotropic with respect to the direction of laser beam polarization. Non-local thermodynamic equilibrium (Non-LTE) models have been implemented to analyze the x-ray spectra to determine the plasma temperature and election density. Evidence of electron beam generation in the supersonic jet plasma was found. The influence of the subpicosecond laser pulse contrast (a ratio between the laser peak intensity and pedestal pulse intensity) on the jets' x-ray emission characteristics is discussed. Surprisingly, it was found that the x-ray yield was not sensitive to the prepulse contrast ratio.

The Santiago-Harvard-Edinburgh-Durham void comparison - I. SHEDding light on chameleon gravity tests

NASA Astrophysics Data System (ADS)

Cautun, Marius; Paillas, Enrique; Cai, Yan-Chuan; Bose, Sownak; Armijo, Joaquin; Li, Baojiu; Padilla, Nelson

2018-05-01

We present a systematic comparison of several existing and new void-finding algorithms, focusing on their potential power to test a particular class of modified gravity models - chameleon f(R) gravity. These models deviate from standard general relativity (GR) more strongly in low-density regions and thus voids are a promising venue to test them. We use halo occupation distribution (HOD) prescriptions to populate haloes with galaxies, and tune the HOD parameters such that the galaxy two-point correlation functions are the same in both f(R) and GR models. We identify both three-dimensional (3D) voids and two-dimensional (2D) underdensities in the plane of the sky to find the same void abundance and void galaxy number density profiles across all models, which suggests that they do not contain much information beyond galaxy clustering. However, the underlying void dark matter density profiles are significantly different, with f(R) voids being more underdense than GR ones, which leads to f(R) voids having a larger tangential shear signal than their GR analogues. We investigate the potential of each void finder to test f(R) models with near-future lensing surveys such as EUCLID and LSST. The 2D voids have the largest power to probe f(R) gravity, with an LSST analysis of tunnel (which is a new type of 2D underdensity introduced here) lensing distinguishing at 80 and 11σ (statistical error) f(R) models with parameters, |fR0| = 10-5 and 10-6, from GR.

Planetary plasma data analysis and 3D visualisation tools of the CDPP in the IMPEx infrastructure

NASA Astrophysics Data System (ADS)

Gangloff, Michel; Génot, Vincent; Khodachenko, Maxim; Modolo, Ronan; Kallio, Esa; Alexeev, Igor; Al-Ubaidi, Tarek; Scherf, Manuel; André, Nicolas; Bourrel, Nataliya; Budnik, Elena; Bouchemit, Myriam; Dufourg, Nicolas; Beigbeder, Laurent

2015-04-01

The CDPP (Centre de Données de la Physique des Plasmas,(http://cdpp.eu/), the French data center for plasma physics, is engaged for more than a decade in the archiving and dissemination of plasma data products from space missions and ground observatories. Besides these activities, the CDPP developed services like AMDA (http://amda.cdpp.eu/) which enables in depth analysis of a large amount of data through dedicated functionalities such as: visualization, conditional search, cataloguing, and 3DView (http://3dview.cdpp.eu/) which provides immersive visualisations in planetary environments and is further developed to include simulation and observational data. Both tools provide an interface to the IMPEx infrastructure (http://impexfp7.oeaw.ac.at) which facilitates the joint access to outputs of simulations (MHD or Hybrid models) in planetary sciences from providers like LATMOS, FMI as well as planetary plasma observational data provided by the CDPP. Several magnetospheric models are implemented in 3Dview (e.g. Tsyganenko for the Earth, and Cain for Mars). Magnetospheric models provided by SINP for the Earth, Jupiter, Saturn and Mercury as well as Hess models for Jupiter can also be used in 3DView, through the IMPEx infrastructure. A use case demonstrating the new capabilities offered by these tools and their interaction, including magnetospheric models, will be presented together with the IMPEx simulation metadata model used for the interface to simulation databases and model providers.

The Examination of the Correlation between Social Physique Anxiety Levels and Narcissism Levels of the Students Who Studied at the SPES

ERIC Educational Resources Information Center

Gezer, Engin

2014-01-01

The aim of the study was to discover the correlation between social physique anxiety levels and narcissism levels of the students of the school of the physical education and sports. A total of 308 students who studied at different academic departments of the school of the physical education and sports of Mustafa Kemal University participated in…

Optimizing Operational Physical Fitness (Optimisation de L’Aptitude Physique Operationnelle)

DTIC Science & Technology

2009-01-01

NORTH ATLANTIC TREATY ORGANISATION RESEARCH AND TECHNOLOGY ORGANISATION AC/323(HFM-080)TP/200 www.rto.nato.int RTO TECHNICAL REPORT TR... RESEARCH AND TECHNOLOGY ORGANISATION AC/323(HFM-080)TP/200 www.rto.nato.int RTO TECHNICAL REPORT TR-HFM-080 Optimizing Operational Physical...Fitness (Optimisation de l’aptitude physique opérationnelle) Final Report of Task Group 019. ii RTO-TR-HFM-080 The Research and

What’s in a Surname? Physique, Aptitude, and Sports Type Comparisons between Tailors and Smiths

PubMed Central

Voracek, Martin; Rieder, Stephan; Stieger, Stefan; Swami, Viren

2015-01-01

Combined heredity of surnames and physique, coupled with past marriage patterns and trade-specific physical aptitude and selection factors, may have led to differential assortment of bodily characteristics among present-day men with specific trade-reflecting surnames (Tailor vs. Smith). Two studies reported here were partially consistent with this genetic-social hypothesis, first proposed by Bäumler (1980). Study 1 (N = 224) indicated significantly higher self-rated physical aptitude for prototypically strength-related activities (professions, sports, hobbies) in a random sample of Smiths. The counterpart effect (higher aptitude for dexterity-related activities among Tailors) was directionally correct, but not significant, and Tailor-Smith differences in basic physique variables were nil. Study 2 examined two large total-population-of-interest datasets (Austria/Germany combined, and UK: N = 7001 and 20532) of men’s national high-score lists for track-and-field events requiring different physiques. In both datasets, proportions of Smiths significantly increased from light-stature over medium-stature to heavy-stature sports categories. The predicted counterpart effect (decreasing prevalences of Tailors along these categories) was not supported. Related prior findings, the viability of possible alternative interpretations of the evidence (differential positive selection for trades and occupations, differential endogamy and assortative mating patterns, implicit egotism effects), and directions for further inquiry are discussed in conclusion. PMID:26161803

Psychophysiological Tracking of a Female Physique Competitor through Competition Preparation

PubMed Central

ROHRIG, BRANDON J.; PETTITT, ROBERT W.; PETTITT, CHERIE D.; KANZENBACH, TODD L.

2017-01-01

Natural physique competitions are based on subjective judgments of how a competitor appears on show day. Prior to competition, there is a prolonged dieting phase referred to as contest preparation. The primary goal is to reduce body fat levels while maintaining skeletal muscle mass. The study tracked the physiological and psychological changes for a 24 year old female preparing for a physique competition. Purpose: The study was conducted to describe the physiological and psychological changes of a female physique competitor who engages in long-term contest preparation. Methods: Diet, body composition, blood work, energy expenditure, mood, and performance were evaluated through contest preparation. Results: The participant lost 10.1kg throughout contest preparation in a strong weekly linear pattern (R2=0.97). Body fat was reduced from 30.45% to 15.85% while fat free mass was maintained. Mood for the participant remained stable until month five, when an observed variation occurred, with performance maintaining. Conclusions: Contest preparation was successful in reducing the body fat in the participant while having a minimum effect on both performance and fat free mass. For athletes looking to lose large amounts of body fat with minimal performance decrements a prolonged diet period with moderate exercise and food restriction can be an effective solution. PMID:28344742

Psychophysiological Tracking of a Female Physique Competitor through Competition Preparation.

PubMed

Rohrig, Brandon J; Pettitt, Robert W; Pettitt, Cherie D; Kanzenbach, Todd L

2017-01-01

Natural physique competitions are based on subjective judgments of how a competitor appears on show day. Prior to competition, there is a prolonged dieting phase referred to as contest preparation. The primary goal is to reduce body fat levels while maintaining skeletal muscle mass. The study tracked the physiological and psychological changes for a 24 year old female preparing for a physique competition. The study was conducted to describe the physiological and psychological changes of a female physique competitor who engages in long-term contest preparation. Diet, body composition, blood work, energy expenditure, mood, and performance were evaluated through contest preparation. The participant lost 10.1kg throughout contest preparation in a strong weekly linear pattern (R 2 =0.97). Body fat was reduced from 30.45% to 15.85% while fat free mass was maintained. Mood for the participant remained stable until month five, when an observed variation occurred, with performance maintaining. Contest preparation was successful in reducing the body fat in the participant while having a minimum effect on both performance and fat free mass. For athletes looking to lose large amounts of body fat with minimal performance decrements a prolonged diet period with moderate exercise and food restriction can be an effective solution.

What's in a Surname? Physique, Aptitude, and Sports Type Comparisons between Tailors and Smiths.

PubMed

Voracek, Martin; Rieder, Stephan; Stieger, Stefan; Swami, Viren

2015-01-01

Combined heredity of surnames and physique, coupled with past marriage patterns and trade-specific physical aptitude and selection factors, may have led to differential assortment of bodily characteristics among present-day men with specific trade-reflecting surnames (Tailor vs. Smith). Two studies reported here were partially consistent with this genetic-social hypothesis, first proposed by Bäumler (1980). Study 1 (N = 224) indicated significantly higher self-rated physical aptitude for prototypically strength-related activities (professions, sports, hobbies) in a random sample of Smiths. The counterpart effect (higher aptitude for dexterity-related activities among Tailors) was directionally correct, but not significant, and Tailor-Smith differences in basic physique variables were nil. Study 2 examined two large total-population-of-interest datasets (Austria/Germany combined, and UK: N = 7001 and 20,532) of men's national high-score lists for track-and-field events requiring different physiques. In both datasets, proportions of Smiths significantly increased from light-stature over medium-stature to heavy-stature sports categories. The predicted counterpart effect (decreasing prevalences of Tailors along these categories) was not supported. Related prior findings, the viability of possible alternative interpretations of the evidence (differential positive selection for trades and occupations, differential endogamy and assortative mating patterns, implicit egotism effects), and directions for further inquiry are discussed in conclusion.

Interoperability science cases with the CDPP tools

NASA Astrophysics Data System (ADS)

Nathanaël, J.; Cecconi, B.; André, N.; Bouchemit, M.; Gangloff, M.; Budnik, E.; Jacquey, C.; Pitout, F.; Durand, J.; Rouillard, A.; Lavraud, B.; Genot, V. N.; Popescu, D.; Beigbeder, L.; Toniutti, J. P.; Caussarieu, S.

2017-12-01

Data exchange protocols are never as efficient as when they are invisible for the end user who is then able to discover data, to cross compare observations and modeled data and finally to perform in depth analysis. Over the years these protocols, including SAMP from IVOA, EPN-TAP from the Europlanet 2020 RI community, backed by standard web-services, have been deployed in tools designed by the French Centre de Données de la Physique des Plasmas (CDPP) including AMDA, the Propagation Tool, 3DView, ... . This presentation will focus on science cases which show the capability of interoperability in the planetary and heliophysics contexts, involving both CDPP and companion tools. Europlanet 2020 RI has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 654208.

Crowd Confrontation and Non-Lethal Weapons: A Literature Review and Conceptual Model

DTIC Science & Technology

2008-03-01

what he knows (cognitive state), and what he feels physically (physical state) or psychologically (emotional state). 7. Communication (i.e. the act of...ressent physiquement (état physique) ou psychologiquement (état émotionnel). 7. La communication (c.-à-d. l’action de transmettre de l’information) joue...riot situations during peacekeeping operations, for example in Drvar, Bosnia, in April 1998 [ Coombs , 2006]. The Canadian Forces thus have a need to

Characteristics of muscle dysmorphia in male football, weight training, and competitive natural and non-natural bodybuilding samples.

PubMed

Baghurst, Timothy; Lirgg, Cathy

2009-06-01

The purpose of this study was to identify differences in traits associated with muscle dysmorphia between collegiate football players (n=66), weight trainers for physique (n=115), competitive non-natural bodybuilders (n=47), and competitive natural bodybuilders (n=65). All participants completed demographic questionnaires in addition to the Muscle Dysmorphia Inventory (Rhea, Lantz, & Cornelius, 2004). Results revealed a significant main effect for group, and post hoc tests found that the non-natural bodybuilding group did not score significantly higher than the natural bodybuilding group on any subscale except for Pharmacological Use. Both the non-natural and natural bodybuilding groups scored significantly higher than those that weight trained for physique on the Dietary Behavior and Supplement Use subscales. The collegiate football players scored lowest on all subscales of the Muscle Dysmorphia Inventory except for Physique Protection where they scored highest. Findings are discussed with future research expounded.

Physique traits of lightweight rowers and their relationship to competitive success

PubMed Central

Slater, G; Rice, A; Mujika, I; Hahn, A; Sharpe, K; Jenkins, D

2005-01-01

Objectives: Physique traits and their relationship to competitive success were assessed amongst lightweight rowers competing at the 2003 Australian Rowing Championships. Methods: Full anthropometric profiles were collected from 107 lightweight rowers (n = 65 males, n = 45 females) competing in the Under 23 and Open age categories. Performance assessments were obtained for 66 of these rowers based on results in the single sculls events. The relationship between physique traits and competitive success was then determined. Results: Lower body fat (heat time estimate –8.4 s kg–1, p<0.01), greater total body mass (heat time estimate –4.4 s kg–1, p = 0.03), and muscle mass (heat time estimate –10.2 s kg–1, p<0.01) were associated with faster 2000 m heat times. Conclusions: The more successful lightweight rowers were those who had lower body fat and greater total muscle mass. PMID:16183770

The influence of social anxiety on the body checking behaviors of female college students.

PubMed

White, Emily K; Warren, Cortney S

2014-09-01

Social anxiety and eating pathology frequently co-occur. However, there is limited research examining the relationship between anxiety and body checking, aside from one study in which social physique anxiety partially mediated the relationship between body checking cognitions and body checking behavior (Haase, Mountford, & Waller, 2007). In an independent sample of 567 college women, we tested the fit of Haase and colleagues' foundational model but did not find evidence of mediation. Thus we tested the fit of an expanded path model that included eating pathology and clinical impairment. In the best-fitting path model (CFI=.991; RMSEA=.083) eating pathology and social physique anxiety positively predicted body checking, and body checking positively predicted clinical impairment. Therefore, women who endorse social physique anxiety may be more likely to engage in body checking behaviors and experience impaired psychosocial functioning. Published by Elsevier Ltd.

The Relationship of Gender and Self-Efficacy on Social Physique Anxiety among College Students.

PubMed

Rothberger, Sara M; Harris, Brandonn S; Czech, Daniel R; Melton, Bridget

The anxiety or fear associated with physique evaluation is defined as Social Physique Anxiety (SPA). Numerous studies have examined this construct, yet a gap exists exploring this phenomenon among current college students with SPA, self-efficacy, and gender concurrently. Therefore, the purposes of this study included quantitatively analyzing the association between SPA, gender, and self-efficacy. Participants included 237 students at a Southeastern university participating in jogging, body conditioning, or weight training courses. Analysis of Variance yielded a significant main effect for self-efficacy as well, as those with lower self-efficacy displayed higher levels of SPA ( p < 0.001). Stepwise regression analysis indicated self-efficacy and gender were both significant predictors of SPA. This information could aid in creating interventions designed to decrease the prevalence of SPA and increase levels of self-efficacy among the current college student population.

Stimulated backward Raman scattering driven collectively by two picosecond laser pulses in a bi- or multi-speckle configuration

NASA Astrophysics Data System (ADS)

Glize, K.; Rousseaux, C.; Bénisti, D.; Dervieux, V.; Gremillet, L.; Baton, S. D.; Lancia, L.

2017-03-01

In this paper, we investigate, both experimentally and numerically, the backward stimulated Raman scattering (SRS) excited collectively by two laser pulses. The experiments have been carried out at the LULI facility using two co-propagating 1- μ m wavelength, 1.5- ps duration laser pulses focused in a preformed underdense plasma. A particular emphasis is laid on the configuration where the pulses are focused side-by-side, with a lateral distance of 80 - 90 μ m , but not simultaneously. It is experimentally demonstrated that a weak-intensity speckle, ineffective when fired alone in a preformed plasma, yields a significant SRS-induced reflectivity if launched a few picoseconds after a strong one. The data have been obtained by using both highly space-time resolved Thomson diagnostics and space-resolved SRS reflectivity measurements. By choosing either parallel or orthogonal polarizations for the two laser pulses, our experiments shed light on the role of either electrostatic or electromagnetic seeding in enhancing SRS from weak-intensity speckles. A major finding is that seeding operates over unexpectedly long times ( 15 - 20 ps under our experimental conditions). Similar results are obtained in lower-density plasmas, or when the weak pulse is smoothed by a random phase plate, thus leading to multiple speckle interaction, while the strong pulse is focused within the speckle pattern. The data are discussed with the help of particle-in-cell numerical simulations, which confirm the destabilizing effect of the strong pulse over the weak one after a short transient time.

Statistical study of mirror mode events in the Earth magnetosheath

NASA Astrophysics Data System (ADS)

Genot, V.; Budnik, E.; Jacquey, C.; Sauvaud, J.; Dandouras, I.; Lucek, E.

2006-12-01

Using a search and classification tool developed at CDPP (Centre de la Physique des Plasmas, http://cdpp.cesr.fr), we investigate the physics of the mirror instability. Indeed both analytical and observational recent studies have shown the paramount importance of this instability in the development of magnetosheath turbulence and its potential role in reconnection. 5 years of Cluster data have been mined by our tool which can be intuitively parametrized and set up with specific constraints on the actual data content. The strength of the method is illustrated by our results concerning the efficiency of different identification procedures. Beyond the presentation of the general mirror mode event distribution in the magnetosheath, some of the key questions we address include : evolution of the wave amplitude with the fractional distance to the boundaries (bow shock/magnetopause), mirror structure behaviour in relation with 1/ local parameters (plasma beta, temperature anisotropy) and 2/ conditioning parameters (solar wind Mach numbers, IMF orientation), tests of theoretical expressions obtained with different closure equations, ... The implications of these results for the mirror mode modelization is discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farmer, W. A.; Koning, J. M.; Strozzi, D. J.

Here, we present radiation-hydrodynamic simulations of self-generated magnetic field in a hohlraum, which show an increased temperature in large regions of the underdense fill. Non-parallel gradients in electron density and temperature in a laser-heated plasma give rise to a self-generated field by the “Biermann battery” mechanism. Here, HYDRA simulations of three hohlraum designs on the National Ignition Facility are reported, which use a partial magnetohydrodynamic (MHD) description that includes the self-generated source term, resistive dissipation, and advection of the field due to both the plasma flow and the Nernst term. Anisotropic electron heat conduction parallel and perpendicular to the fieldmore » is included, but not the Righi-Leduc heat flux. The field strength is too small to compete significantly with plasma pressure, but affects plasma conditions by reducing electron heat conduction perpendicular to the field. Significant reductions in heat flux can occur, especially for high Z plasma, at modest values of the Hall parameter, Ω eτ ei≲1, where Ω e = eB/m ec and τ ei is the electron-ion collision time. The inclusion of MHD in the simulations leads to 1 keV hotter electron temperatures in the laser entrance hole and high- Z wall blowoff, which reduces inverse-bremsstrahlung absorption of the laser beam. This improves propagation of the inner beams pointed at the hohlraum equator, resulting in a symmetry shift of the resulting capsule implosion towards a more prolate shape. The time of peak x-ray production in the capsule shifts later by only 70 ps (within experimental uncertainty), but a decomposition of the hotspot shape into Legendre moments indicates a shift of P 2/P 0 by ~20%. As a result, this indicates that MHD cannot explain why simulated x-ray drive exceeds measured levels, but may be partially responsible for failures to correctly model the symmetry.« less

Simulation of self-generated magnetic fields in an inertial fusion hohlraum environment

DOE PAGES

Farmer, W. A.; Koning, J. M.; Strozzi, D. J.; ...

2017-05-09

Here, we present radiation-hydrodynamic simulations of self-generated magnetic field in a hohlraum, which show an increased temperature in large regions of the underdense fill. Non-parallel gradients in electron density and temperature in a laser-heated plasma give rise to a self-generated field by the “Biermann battery” mechanism. Here, HYDRA simulations of three hohlraum designs on the National Ignition Facility are reported, which use a partial magnetohydrodynamic (MHD) description that includes the self-generated source term, resistive dissipation, and advection of the field due to both the plasma flow and the Nernst term. Anisotropic electron heat conduction parallel and perpendicular to the fieldmore » is included, but not the Righi-Leduc heat flux. The field strength is too small to compete significantly with plasma pressure, but affects plasma conditions by reducing electron heat conduction perpendicular to the field. Significant reductions in heat flux can occur, especially for high Z plasma, at modest values of the Hall parameter, Ω eτ ei≲1, where Ω e = eB/m ec and τ ei is the electron-ion collision time. The inclusion of MHD in the simulations leads to 1 keV hotter electron temperatures in the laser entrance hole and high- Z wall blowoff, which reduces inverse-bremsstrahlung absorption of the laser beam. This improves propagation of the inner beams pointed at the hohlraum equator, resulting in a symmetry shift of the resulting capsule implosion towards a more prolate shape. The time of peak x-ray production in the capsule shifts later by only 70 ps (within experimental uncertainty), but a decomposition of the hotspot shape into Legendre moments indicates a shift of P 2/P 0 by ~20%. As a result, this indicates that MHD cannot explain why simulated x-ray drive exceeds measured levels, but may be partially responsible for failures to correctly model the symmetry.« less

Simulation of self-generated magnetic fields in an inertial fusion hohlraum environment

NASA Astrophysics Data System (ADS)

Farmer, W. A.; Koning, J. M.; Strozzi, D. J.; Hinkel, D. E.; Berzak Hopkins, L. F.; Jones, O. S.; Rosen, M. D.

2017-05-01

We present radiation-hydrodynamic simulations of self-generated magnetic field in a hohlraum, which show an increased temperature in large regions of the underdense fill. Non-parallel gradients in electron density and temperature in a laser-heated plasma give rise to a self-generated field by the "Biermann battery" mechanism. Here, HYDRA simulations of three hohlraum designs on the National Ignition Facility are reported, which use a partial magnetohydrodynamic (MHD) description that includes the self-generated source term, resistive dissipation, and advection of the field due to both the plasma flow and the Nernst term. Anisotropic electron heat conduction parallel and perpendicular to the field is included, but not the Righi-Leduc heat flux. The field strength is too small to compete significantly with plasma pressure, but affects plasma conditions by reducing electron heat conduction perpendicular to the field. Significant reductions in heat flux can occur, especially for high Z plasma, at modest values of the Hall parameter, Ωeτei≲1 , where Ωe=e B /mec and τei is the electron-ion collision time. The inclusion of MHD in the simulations leads to 1 keV hotter electron temperatures in the laser entrance hole and high-Z wall blowoff, which reduces inverse-bremsstrahlung absorption of the laser beam. This improves propagation of the inner beams pointed at the hohlraum equator, resulting in a symmetry shift of the resulting capsule implosion towards a more prolate shape. The time of peak x-ray production in the capsule shifts later by only 70 ps (within experimental uncertainty), but a decomposition of the hotspot shape into Legendre moments indicates a shift of P2/P0 by ˜20 % . This indicates that MHD cannot explain why simulated x-ray drive exceeds measured levels, but may be partially responsible for failures to correctly model the symmetry.

PREFACE: 31st European Physical Society Conference on Plasma Physics

NASA Astrophysics Data System (ADS)

Dendy, Richard

2004-12-01

This special issue of Plasma Physics and Controlled Fusion comprises refereed papers contributed by invited speakers at the 31st European Physical Society Conference on Plasma Physics. The conference was jointly hosted by the Rutherford Appleton Laboratory, by the EURATOM/UKAEA Fusion Association and by Imperial College London, where it took place from 28 June to 2 July 2004. The overall agenda for this conference was set by the Board of the Plasma Physics Division of the European Physical Society, chaired by Friedrich Wagner (MPIPP, Garching) and his successor Jo Lister (CRPP, Lausanne). It built on developments in recent years, by further increasing the scientific diversity of the conference programme, whilst maintaining its depth and quality. A correspondingly diverse Programme Committee was set up, whose members are listed below. The final task of the Programme Committee has been the preparation of this special issue. In carrying out this work, as in preparing the scientific programme of the conference, the Programme Committee formed specialist subcommittees representing the different fields of plasma science. The chairmen of these subcommittees, in particular, accepted a very heavy workload on behalf of their respective research communities. It is a great pleasure to take this opportunity to thank: Emilia R Solano (CIEMAT, Madrid), magnetic confinement fusion; Jürgen Meyer-ter-Vehn (MPQ, Garching), laser-plasma interaction and beam plasma physics; and Jean-Luc Dorier (CRPP, Lausanne), dusty plasmas. The relatively few papers in astrophysical and basic plasma physics were co-ordinated by a small subcommittee which I led. Together with Peter Norreys (RAL, Chilton), we five constitute the editorial team for this special issue. The extensive refereeing load, compressed into a short time interval, was borne by the Programme Committee members and by many other experts, to whom this special issue owes much. We are also grateful to the Local Organizing Committee chaired by Henry Hutchinson (RAL, Chilton), and to the Plasma Physics and Controlled Fusion journal team (Institute of Physics Publishing, Bristol), for their work on this conference. At the 2004 European Physical Society Conference on Plasma Physics, plenary invited speakers whose talks spanned the entire field were followed, each day, by multiple parallel sessions which also included invited talks. Invited speakers in both these categories were asked to contribute papers to this special issue (the contributed papers at this conference, and at all recent conferences in this series, are archived at http://epsppd.epfl.ch). The Programme Committee is very grateful to the many invited speakers who have responded positively to this request. Invited papers appear here in their order of presentation during the week beginning 28 June 2004; this ordering provides an echo of the character of the conference, as it was experienced by those who took part. Programme Committee 2004 Professor Richard Dendy UKAEA Culham Division, UK Chairman and guest editor Dr Jean-Luc Dorier Centre de Recherches en Physique des Plasmas, Lausanne, Switzerland (Co-ordinator of dusty plasmas and guest editor) Professor Jürgen Meyer-ter-Vehn Max-Planck-Institut für Quantenoptik, Garching, Germany (Co-ordinator of laser-plasma interaction and beam plasma physics and guest editor) Dr Peter Norreys Rutherford Appleton Laboratory, Chilton, UK (Scientific Secretary and guest editor) Dr Emilia R Solano CIEMAT Laboratorio Nacional de Fusión, Madrid, Spain ( Co-ordinator of magnetic confinement fusion and guest editor) Dr Shalom Eliezer Soreq Nuclear Research Centre, Israel Dr Wim Goedheer FOM-Instituut voor Plasmafysica, Rijnhuizen, Netherlands Professor Henry Hutchinson Rutherford Appleton Laboratory, Chilton, UK Professor John Kirk Max-Planck-Institut für Kernphysik, Heidelberg, Germany Dr Raymond Koch Ecole Royale Militaire/Koninklijke Militaire School, Brussels, Belgium Professor Gerrit Kroesen Technische Universiteit Eindhoven, Netherlands Dr Martin Lampe Naval Research Laboratory, Washington DC, USA Dr Jo Lister Centre de Recherches en Physique des Plasmas, Lausanne, Switzerland Dr Paola Mantica Istituto di Fisica del Plasma, Milan, Italy Professor Tito Mendonca Instituto Superior Tecnico, Lisbon, Portugal Dr Patrick Mora École Polytechnique, Palaiseau, France Professor Lennart Stenflo Umeå Universitet, Sweden Professor Paul Thomas CEA Cadarache, Saint-Paul-lez-Durance, France Professor Friedrich Wagner Max-Planck-Institut fr Plasmaphysik, Garching, Germany Professor Hannspeter Winter Technische Universität Wien, Austria

Nonlinear Electron and Ion Density Modulations Driven by Interfering High-Intensity Laser Pulses

NASA Astrophysics Data System (ADS)

Chen, S.; Zhang, P.; Saleh, N.; Sheng, Z. M.; Widjaja, C.; Umstadter, D.

2002-11-01

The optical spectrum from interaction of two crossed ultra short laser beams (400 fs) with underdense plasma is measured at various angles. Enhancement and broadening of the spectrum in the forward direction of one of the beams shows evidence of energy transfer between the two laser beams(G. Shvets, N. J. Fisch, A. Pukhov, and J. Meyer-ter-Vehn, Phys. Rev. E 60, 2218 (1999).), which is confirmed by a 2-D PIC simulation. The spectrum and scattered power indicate that a large amplitude electron density modulation is driven, which is attributed to the ponderomotive force of the interference, in agreement with simple analysis and simulation(δn/n_0>10). Stokes and anti-Stokes satellites reveals that the energy transfer is accompanied by a large amplitude nonlinear ion acoustic wave created by the laser interference in the strongly driven limit. The wavelength shift indicates that the ion acoustic wave's speed is 2.3×10^6m/s, corresponding to the electron temperature 119 keV, which is attributed to stochastic heating, also found in the simulation. Besides being of interest in basic plasma physics, this research is also relevant to fast igniter fusion or ion acceleration experiments, in which a laser pulse may potentially beat with a reflected weaker pulse, with intensities comparable to those used in the experiment(Y. Sentoku, et al., Appl. Phys. B 74, 207-215 (2002).).

Torleif Ericson 60th Birthday

ScienceCinema

None

2017-12-09

Plusieurs discours à l'occasion du 60me anniversaire de Torleif Ericson, physicien né à Lund (Suède), et remerciements pour son travail et son effort de relier la physique des particules à la physique nucléaire. A la fin de la cérémonie un document scientifique de 400 pages "die Festschrift" lui est remis comme cadeau d'anniversaire avec un grand nombre de contributions d'amis etc...

Ohio State University Symposium (45th) on Molecular Spectroscopy Held in Columbus, Ohio on 11-15 Jun 1990

DTIC Science & Technology

1990-06-15

Atmospheric Administration, Boulder, CO 80303. Address of Ortigoso and Escribano: Instituto de Estructura de al Materia, Consejo Superior de investigaciones ...10 min.(1:42) J. M. GUILMOT anO M. HERMAN, Laboratoire de Chimie Physique Moleculaire, tjniversit’c Libre de ...CANY-PEYRET, Laboratoire de Physique Mole’*u’ai:e et Atmospherique, Universite Pierre et Marie Curie et CNRS, 75252 Paris, France. MF4. FIR LASER STARK

Women's anxiety about social and exercise settings.

PubMed

Walton, Vicki R; Finkenberg, Mel E

2002-04-01

This study involved a comparison of social physique anxiety, assessed through the application of a modified version of the Social Physique Anxiety Scale, with 28 women who were new members exercising at all-female facilities compared to 43 new female members exercising at coeducational facilities. Analyses indicated there were no significant differences in means between the groups. The scores of women attending all-female facilities were significantly more influenced by the sex of members when choosing a facility.

Influence of players' physique on rugby football injuries.

PubMed Central

Lee, A J; Myers, J L; Garraway, W M

1997-01-01

OBJECTIVES: To determine whether there is an association between a player's physique and injuries incurred while playing rugby football. METHODS: A cohort study was carried out involving all senior rugby clubs in the Scottish Borders during the 1993-1994 rugby season. Somatotype estimates were determined for 1152 (95%) of the 1216 eligible players. Body mass index (BMI), chest to waist ratio, and the ponderal index (PI) were used to classify players' physique as endomorphic (obese), mesomorphic (muscular), and ectomorphic (linear). RESULTS: A strong association was found between physique and age (chi 2 test: chi 2 = 317.2, df = 10, P < 0.0001). More younger players were ectomorphs. Older players were more often endomorphic. The physiques of forwards and backs were significantly different (chi 2 test: chi 2 = 58.6, df = 2, P < 0.0001), with forwards being of a heavier build than three-quarters, even after adjustment for age. Endomorphic players were more likely than ectomorphs to be injured in a match after adjustment for age (age-adjusted mean BMI for players who were injured in a match was 25.4 compared with 24.6 for players who were not injured in a match, P < 0.0001; adjusted chest to waist ratio means were 1.136 and 1.125 respectively, P = 0.0307; adjusted PI means were 0.414 and 0.417 respectively, P = 0.0056). Increased risk of injury may occur when players play out of position, since one fifth of all injuries occurred in this circumstance. CONCLUSIONS: Further research needs to be conducted using a more objective method of measuring somatotype on a further cohort of players so that the risk of injury for different body types can be examined more closely and related to other potential confounding factors. The level of increased risk for individuals playing out of their usual playing position needs to be established with a greater degree of certainty. PMID:9192128

Encyclopédie scientifique de l'universe: les étoiles - le système solaire.

NASA Astrophysics Data System (ADS)

This book is a revised, extended and updated edition of the volume published in 1979 (27.003.156).Contents: Première partie - le système solaire: 1. Astronomie des positions (J. Lévy). 2. Le système des constantes astronomiques; les données fondamentales (A. Bec-Borsenberger, F. Chollet). 3. Mécanique du système solaire (B. Morando). 4. Relief et structure des planètes telluriques et des satellites (A. Cazenave, P. Masson, P. Thomas). 5. Physique des atmosphères planétaires denses (D. Gautier, M. Combes,G. Moreels, J. P. Parisot, O. Tallagrand). 6. Les anneaux entourant les planètes (N. Borderies, A. Dollfus). 7. Les comètes et les météorites (A. Levasseur-Regourd). 8. L'environnement du Soleil et de la Terre (J.-L. Steinberg, J.-P. Bibring, A. Boischot, P. Couturier, R. Dumont, T. Encrenaz, P. Lamy).Deuxième partie - le Soleil et les bases de la physique stellaire: 9. Théorie des atmosphères du Soleil et des étoiles (R. Michard). 10. Physique de l'atmosphère solaire {non perturbée} (P. Mein). 11. Les centres actifs (J.-C. Hénoux, J.-C. Vial). 12. Éruptions solaires et phénomènes transitoires (J.-C. Hénoux, M. Pick, G. Trottet). 13. Le cycle solaire (J. Latour, P. Simon).Troisième partie - physique des étoiles: 14. Acquisition des données fondamentales (F. Spite). 15. Les étoiles doubles (R. Bouigue, P. Muller). 16. Les étoiles variables (M. Auvergne, A. Baglin, D. Ducatel, J.-M. Le Contel, J. C. Valtier). 17. Structure interne et évolution des étoiles (J.-P. Zahn). 18. Les familles physiques d'étoiles (G. Cayrel).

Canadian Journal of Physics. Volume 69, Number 2 (Revue Canadienne de Physique. Volume 69, Numero 2

DTIC Science & Technology

1991-02-01

4KNational Research Conseil national Council Canada de recherches Canada SMC CtRC Canadian Journal Revue canadienne of Physics de physique Volume 69...Number 2, February 1991 Volume 69, num~ro 2, W~rier 1991 AD-A235 711 Aviliable for $36.00 from National Research Council of Canada, Ottawa, Ont...Publid par THE NATIONAL RESEARCH COUNCIL OF CANADA LE CONSEIL NATIONAL DE RECHERCHES DU CANADA Editor R. W. NICHOLLS Directeur scientifique Editorial

MICROMECHANICS AND MICROSTRUCTURE EVOLUTION: Modeling, Simulation and Experiments. Held in Madrid, Spain on 12-16 September 2005

DTIC Science & Technology

2006-10-30

acknowledges funding from the ‘‘ Programa Torres Quevedo’’ of the Spanish Ministerio de Educación y Ciencia. References [1] Nix WD. Metall Mater Trans A...University of Madrid E. T. S. de Ingenieros de Caminos Madrid 28040 Spain 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 10. SPONSOR...Rodney * Génie Physique et Mécanique des Matériaux (UMR CNRS 5010), Institut National Polytechnique de Grenoble, 101 rue de la Physique, 38402

Micromechanics and Microstructure Evolution: Modeling, Simulation and Experiments. Conference Held in Madrid, Spain, 12-16 Sep 2005

DTIC Science & Technology

2006-10-30

acknowledges funding from the ‘‘ Programa Torres Quevedo’’ of the Spanish Ministerio de Educación y Ciencia. References [1] Nix WD. Metall Mater Trans A...University of Madrid E. T. S. de Ingenieros de Caminos Madrid 28040 Spain 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 10. SPONSOR...Rodney * Génie Physique et Mécanique des Matériaux (UMR CNRS 5010), Institut National Polytechnique de Grenoble, 101 rue de la Physique, 38402

Modeling the human body shape in bioimpedance vector measurements.

PubMed

Kim, Chul-Hyun; Park, Jae-Hyeon; Kim, Hyeoijin; Chung, Sochung; Park, Seung-Hun

2010-01-01

Human body shape, called somatotype, has described physique of humans in health and sports applications, relating anthropometric measurements to fatness, muscularity and linearity in a structured way. Here we propose a new method based on bioelectric impedance vector analysis (BIVA) of R/H and Xc/H to represent the cross-sectional area and the body cell mass in a given surface area (m(2)) respectively. Data from six gymnasts, ten dancers, and five fashion models, groups whose physiques and BMI ranges were distinct from one another, were measured for somatotype and BIVA. The models had highest values of the R/H and gymnasts the lowest. Xc/H was lower in models than in the dancers and gymnasts (p < 0.05). Phase angle was lowest in the models and highest in gymnasts significantly (p < 0.05). Pattern analysis from BIVA corresponded to the calculated anthropometric somatotype supporting the hypothesis that BIA's resistance (R) and reactance (Xc) are meaningful discriminates of body size and function which relate to physique in a purposive way.

Psychometric properties of the Social Physique Anxiety Scale (SPAS-7) in Spanish adolescents.

PubMed

Sáenz-Alvarez, Piedad; Sicilia, Álvaro; González-Cutre, David; Ferriz, Roberto

2013-01-01

The purpose of this study was to validate the Spanish version of Motl and Conroy's model of the Social Physique Anxiety Scale (SPAS-7). To achieve this goal, a sample of 398 secondary school students was used, and the psychometric properties of the SPAS-7 were examined through different analyses. The results supported the seven-item model, although the item 5 did not show any significant correlation with two items from this model and had a lower factor loading than the rest of items. The structure of the model was invariant across gender and Body Mass Index (BMI). Alpha value over .70 and suitable levels of temporal stability were obtained. Girls and students classified according to the BMI as overweight and obese had higher scores in social physique anxiety than boys and the group classified as underweight and normal range. The findings of this study provided reliability and validity for the SPAS-7 in a Spanish adolescent sample.

Dermatoglyphic characters and physique: a correlation study.

PubMed

Rothhammer, F; Llop, E; Neel, J V

1982-01-01

The association of anthropometrics, particularly hand measurements, with dermatoglyphic characters is quantified. Children with square hands exhibit higher main line indices, a-b ridge counts, and more open atd angles. Adults with broader hands have more arches. Taller individuals with larger hands present higher a-b ridge counts and leaner subjects with long narrow hands, closer atd angles. The correlation of physique and dermatoglyphics is small but if verified, suggests that at early fetal stages, factors responsible for the establishment of dermatoglyphic patterns interact with genetic determinants of adult shape that are already active.

Novel aspects of direct laser acceleration of relativistic electrons

NASA Astrophysics Data System (ADS)

Arefiev, Alexey

2015-11-01

Production of energetic electrons is a keystone aspect of ultraintense laser-plasma interactions that underpins a variety of topics and applications, including fast ignition inertial confinement fusion and compact particle and radiation sources. There is a wide range of electron acceleration regimes that depend on the duration of the laser pulse and the plasma density. This talk focuses on the regime in which the plasma is significantly underdense and the laser pulse duration is longer than the electron response time, so that, in contrast to the wakefield acceleration regime, the pulse creates a quasi-static channel in the electron density. Such a regime is of particular interest, since it can naturally arise in experiments with solid density targets where the pre-pulse of an ultraintense laser produces an extended sub-critical pre-plasma. This talk examines the impact of several key factors on electron acceleration by the laser pulse and the resulting electron energy gain. A detailed consideration is given to the role played by: (1) the static longitudinal electric field, (2) the static transverse electric field, (3) the electron injection into the laser pulse, (4) the electromagnetic dispersion, and (5) the static longitudinal magnetic field. It is shown that all of these factors lead, under conditions outlined in the talk, to a considerable electron energy gain that greatly exceeds the ponderomotive limit. The static fields do not directly transfer substantial energy to electrons. Instead, they alter the longitudinal dephasing between the electrons and the laser pulse, which then allows the electrons to gain extra energy from the pulse. The talk will also outline a time-resolution criterion that must be satisfied in order to correctly reproduce these effects in particle-in-cell simulations. Supported by AFOSR Contract No. FA9550-14-1-0045, National Nuclear Security Administration Contract No. DE-FC52-08NA28512, and US Department of Energy Contract No. DE-FG02-04ER54742.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casner, A.; Masse, L.; Delorme, B.

Understanding and mitigating hydrodynamic instabilities and the fuel mix are the key elements for achieving ignition in Inertial Confinement Fusion. Cryogenic indirect-drive implosions on the National Ignition Facility have evidenced that the ablative Rayleigh-Taylor Instability (RTI) is a driver of the hot spot mix. This motivates the switch to a more flexible higher adiabat implosion design [O. A. Hurricane et al., Phys. Plasmas 21, 056313 (2014)]. The shell instability is also the main candidate for performance degradation in low-adiabat direct drive cryogenic implosions [Goncharov et al., Phys. Plasmas 21, 056315 (2014)]. This paper reviews recent results acquired in planar experimentsmore » performed on the OMEGA laser facility and devoted to the modeling and mitigation of hydrodynamic instabilities at the ablation front. In application to the indirect-drive scheme, we describe results obtained with a specific ablator composition such as the laminated ablator or a graded-dopant emulator. In application to the direct drive scheme, we discuss experiments devoted to the study of laser imprinted perturbations with special phase plates. The simulations of the Richtmyer-Meshkov phase reversal during the shock transit phase are challenging, and of crucial interest because this phase sets the seed of the RTI growth. Recent works were dedicated to increasing the accuracy of measurements of the phase inversion. We conclude by presenting a novel imprint mitigation mechanism based on the use of underdense foams. Lastly, the foams induce laser smoothing by parametric instabilities thus reducing the laser imprint on the CH foil.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casner, A., E-mail: alexis.casner@cea.fr; Masse, L.; Huser, G.

Understanding and mitigating hydrodynamic instabilities and the fuel mix are the key elements for achieving ignition in Inertial Confinement Fusion. Cryogenic indirect-drive implosions on the National Ignition Facility have evidenced that the ablative Rayleigh-Taylor Instability (RTI) is a driver of the hot spot mix. This motivates the switch to a more flexible higher adiabat implosion design [O. A. Hurricane et al., Phys. Plasmas 21, 056313 (2014)]. The shell instability is also the main candidate for performance degradation in low-adiabat direct drive cryogenic implosions [Goncharov et al., Phys. Plasmas 21, 056315 (2014)]. This paper reviews recent results acquired in planar experimentsmore » performed on the OMEGA laser facility and devoted to the modeling and mitigation of hydrodynamic instabilities at the ablation front. In application to the indirect-drive scheme, we describe results obtained with a specific ablator composition such as the laminated ablator or a graded-dopant emulator. In application to the direct drive scheme, we discuss experiments devoted to the study of laser imprinted perturbations with special phase plates. The simulations of the Richtmyer-Meshkov phase reversal during the shock transit phase are challenging, and of crucial interest because this phase sets the seed of the RTI growth. Recent works were dedicated to increasing the accuracy of measurements of the phase inversion. We conclude by presenting a novel imprint mitigation mechanism based on the use of underdense foams. The foams induce laser smoothing by parametric instabilities thus reducing the laser imprint on the CH foil.« less

Hydrodynamics simulations of 2{omega} laser propagation in underdense gasbag plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meezan, N.B.; Divol, L.; Marinak, M.M.

2004-12-01

Recent 2{omega} laser propagation and stimulated Raman backscatter (SRS) experiments performed on the Helen laser have been analyzed using the radiation-hydrodynamics code HYDRA [M. M. Marinak, G. D. Kerbel, N. A. Gentile, O. Jones, D. Munro, S. Pollaine, T. R. Dittrich, and S. W. Haan, Phys. Plasmas 8, 2275 (2001)]. These experiments utilized two diagnostics sensitive to the hydrodynamics of gasbag targets: a fast x-ray framing camera (FXI) and a SRS streak spectrometer. With a newly implemented nonlocal thermal transport model, HYDRA is able to reproduce many features seen in the FXI images and the SRS streak spectra. Experimental andmore » simulated side-on FXI images suggest that propagation can be explained by classical laser absorption and the resulting hydrodynamics. Synthetic SRS spectra generated from the HYDRA results reproduce the details of the experimental SRS streak spectra. Most features in the synthetic spectra can be explained solely by axial density and temperature gradients. The total SRS backscatter increases with initial gasbag fill density up to {approx_equal}0.08 times the critical density, then decreases. Data from a near-backscatter imaging camera show that severe beam spray is not responsible for the trend in total backscatter. Filamentation does not appear to be a significant factor in gasbag hydrodynamics. The simulation and analysis techniques established here can be used in ongoing experimental campaigns on the Omega laser facility and the National Ignition Facility.« less

High Maternal Age and Low Pre-Pregnancy Body Mass Index Correlate with Lower Birth Weight of Male Infants.

PubMed

Fukuda, Sayuri; Tanaka, Yurika; Harada, Kiyomi; Saruwatari, Ayako; Kitaoka, Kaori; Odani, Kiyoko; Aoi, Wataru; Wada, Sayori; Nishi, Yukari; Oguni, Tatsuya; Asano, Hiroaki; Hagiwara, Nobuko; Higashi, Akane

2017-02-01

In Japan, the percentage of leanness has been increasing in young women, and the percentage of low birth weight infants (< 2,500 g) has increased. Moreover, the average age of primiparas rose 3.5 years during the last 30 years. The purpose of this study was to clarify the relationship between maternal age and the influence of maternal pre-pregnancy physique on the neonatal physique of infants. Questionnaires were issued to the participants and collected when they submitted their gestational notifications at their local ward office in Kyoto Prefecture. After delivery, we obtained information on the course of the pregnancy and the neonatal physique of the infants from the participant's maternal passbooks. A total of 454 mothers (age 20 ≥) were analyzed: 161 young mothers (aged 20 to 29 years), 185 mothers (aged 30 to 34 years), and 108 older mothers (age ≥ 35). Overall, the mean rate of leanness (pre-pregnancy BMI < 18.5) was 23.8%. We found that birth weight was significantly lower in female infants, born to lean young mothers, compared to non-lean young mothers, whereas no significant difference was detected in other mothers (age ≥ 30), irrespective of pre-pregnancy BMI. By contrast, male infants, born to older lean mothers (age ≥ 35), showed significantly lower birth weight. Thus, maternal pre-pregnancy BMI exerts differential effects on the fetal growth (neonatal physique), depending on the maternal age and the sex of infants. We need to improve BMI in pre-pregnancy women, especially those in the twenties and 35 years old or over.

Physique and Body Composition in Soccer Players across Adolescence

PubMed Central

Nikolaidis, Pantelis Theodoros; Vassilios Karydis, Nikos

2011-01-01

Purpose Although the contribution of physique and body composition in soccer performance was recognized, these parameters of physical fitness were not well-studied in adolescent players. Aim of this study was to investigate physique and body composition across adolescence. Methods Male adolescents (N=297 aged 12.01–20.98 y), classified into nine one-year age-groups, child (control group, N=16 aged 7.34–11.97 y) and adult players (control group, N=29 aged 21.01–31.59 y), all members of competitive soccer clubs, performed a series of anthropometric measures (body mass, height, skinfolds, circumferences and girths), from which body mass index (BMI), percentage of body fat (BF%), fat mass (FM), fat free mass (FFM) and somatotype (Heath-Carter method) were calculated. Results Age had a positive association with FM (r=0.2, P<0.001) and FFM (r=0.68, P<0.001), and a negative association with BF (r=−0.12, P=0.047). Somatotype components changed across adolescence as well; age was linked to endomorphy (r=−0.17, P=0.005), mesomorphy (r=0.14, P=0.019) and ectomorphy (r=−0.17, P=0.004). Compared with age-matched general population, participants exhibited equal body mass, higher stature, lower body mass index and lower BF. Conclusion During adolescence, soccer players presented significant differences in terms of body composition and physique. Thus, these findings could be employed by coaches and fitness trainers engaged in soccer training in the context of physical fitness assessment and talent identification. PMID:22375222

IslandFAST: A Semi-numerical Tool for Simulating the Late Epoch of Reionization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yidong; Chen, Xuelei; Yue, Bin

2017-08-01

We present the algorithm and main results of our semi-numerical simulation, islandFAST, which was developed from 21cmFAST and designed for the late stage of reionization. The islandFAST simulation predicts the evolution and size distribution of the large-scale underdense neutral regions (neutral islands), and we find that the late Epoch of Reionization proceeds very fast, showing a characteristic scale of the neutral islands at each redshift. Using islandFAST, we compare the impact of two types of absorption systems, i.e., the large-scale underdense neutral islands versus small-scale overdense absorbers, in regulating the reionization process. The neutral islands dominate the morphology of themore » ionization field, while the small-scale absorbers dominate the mean-free path of ionizing photons, and also delay and prolong the reionization process. With our semi-numerical simulation, the evolution of the ionizing background can be derived self-consistently given a model for the small absorbers. The hydrogen ionization rate of the ionizing background is reduced by an order of magnitude in the presence of dense absorbers.« less

Spaced antenna diversity in temperate latitude meteor burst systems operating near 40 MHz - Variation of signal cross-correlation coefficients with antenna separation

NASA Astrophysics Data System (ADS)

Cannon, Paul S.; Shukla, Anil K.; Lester, Mark

1993-04-01

We have studied 37-MHz signals received over an 800-km temperate latitude path using 400-W continuous wave transmissions. Signals collected during a 9-day period in February 1990 on two antennas at separations of 5, 10, and 20 lambda were analyzed. Three signal categories were identified (overdense, underdense, and not known (NK)) and cross-correlation coefficients between the signals received by the two antennas were calculated for each signal category. No spatial variation, and in particular no decrease, in average cross-correlation coefficient was observed for underdense or NK signals as the antenna spacing was increased from 5 to 20 lambda. At each antenna separation the cross-correlation coefficients of these two categories were strongly dependent on time. Overdense signals, however, showed no cross-correlation time dependency at 5 and 10 lambda, but there was a strong time dependency at 20 lambda. Recommendations are made in regard to the optimum antenna spacing for a meteor burst communication system using spaced antenna diversity.

Club of Rome

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2006-04-18

Le Club de Rome s'est fait connaître du grand public par la publication du premier ouvrage "Halte à la croissance" qui a fait l'object d'un débat, il y a 2 ans. Le Prof. Tinbergen a commencé par s'adonner à la physique, il est docteur en physique et très tôt il s'est tourné vers les problèmes sociaux économiques. Il est expert auprès des nombreux gouvernements et organisations internationales et il a vu ses travaux couronnés par le prix Nobel en 1969.

Major Events Coordinated Security Solutions Technical Report Closeout (MECSS): The Application of Science and Technology to Reduce Risk for V2010 and G8/G20 Summits

DTIC Science & Technology

2010-12-01

CBRNE), aux infrastructures essentielles, à la surveillance, à la sécurité physique, à la cybernétique et à la socio- psychologie . Le présent rapport...la socio- psychologie . Dans le cadre du projet SCSGE, on a produit plus de 195 rapports scientifiques, fruit des efforts, du dévouement et du...aux infrastructures essentielles, à la surveillance, à la sécurité physique, à la cybernétique et à la socio- psychologie . Le présent rapport

Etude theorique des fluctuations structurales dans les composes organiques a dimensionnalite reduite

NASA Astrophysics Data System (ADS)

Dumoulin, Benoit

Les systemes a dimensionnalite reduite constituent maintenant une branche entiere de la physique de la matiere condensee. Cette derniere s'est developpee rapidement au cours des dernieres annees, avec la decouverte des materiaux organiques qui presentent, justement, des proprietes physiques fortement anisotropes. Cette these presente une etude en trois parties de plusieurs composes organiques qui, bien que tres differents du point de vue de leurs compositions chimiques et de leurs proprietes physiques a haute temperature, subissent tous une instabilite structurale a tres basse temperature. De plus, dans chacun des cas, l'instabilite structurale est precedee d'un important regime fluctuatif a partir duquel les proprietes physiques changent de maniere significative. Notre etude suit un ordre chronologique inverse puisque nous nous attardons en premier lieu au cas de composes recemment decouverts: les composes de la famille des (BCPTTF)2X (X = PF6 , AsF6). Ces derniers sont des isolants magnetiques a la temperature ambiante et subissent une instabilite structurale de type spin-Peierls a une temperature appelee TSP. En particulier, nous nous interessons a l'etude des proprietes physiques de ces systemes dans le regime fluctuatif, qui precede cette instabilite. Notre etude theorique nous permet de comprendre en detail comment ces systemes s'approchent de l'instabilite struturale. Dans la seconde partie de cette these, nous etudions le regime fluctuatif (pre-transitionnel) observe experimentalement dans le compose de (TMTTF)2PF6. Ce compose organique, dont la structure s'apparente aux sels de Bechgaard, subit une instabilite de type spin-Peierls a une temperature T SP = 19K. Bien que ce compose possede la particularite d'etre un bon conducteur a la temperature ambiante, il subit une transition de type Mott-Hubbard a une temperature Trho ≈ 220K et devient alors un isolant magnetique, analogue aux composes de la famille des (BCPTTF)2X. Le regime fluctuatif precedant l'instabilite spin-Peierls apparait ensuite vers 60K. Notre etude theorique montre qu'un modele d'electrons en interaction de type "g-ologie" avec possibilite de processus umklapp permet de bien rendre compte des proprietes physiques de ce systeme. Finalement, la troisieme partie de cette these porte sur l'etude des premiers composes organiques quasi-unidimensionnels a avoir ete synthetises: les composes de la famille du TTF-TCNQ. Notre etude theorique des instabilites structurales que presentent ces composes n'est evidemment pas la premiere. L'originalite de cette derniere est qu'elle tient compte des fortes interactions entre les electrons, presentent dans ces composes. Pour tenir compte de telles interactions, nous avons choisi la formulation "liquide de Luttinger" qui nous permet de mieux traiter ce regimne dit de couplage fort.

Prospective associations of concerns about physique and the development of obesity, binge drinking, and drug use among adolescent boys and young adult men.

PubMed

Field, Alison E; Sonneville, Kendrin R; Crosby, Ross D; Swanson, Sonja A; Eddy, Kamryn T; Camargo, Carlos A; Horton, Nicholas J; Micali, Nadia

2014-01-01

Relatively little is known about the prevalence of concerns with physique and eating disorders among males and their relation to subsequent adverse outcomes. A broader range of eating disorders needs to be defined to diagnose these illnesses appropriately in males. To investigate whether males with psychiatric symptoms related to disordered eating and concern about physique are more likely to become obese, to start using drugs, to consume alcohol frequently (binge drinking), or to develop high levels of depressive symptoms. The data come from questionnaires sent every 12 to 36 months from 1999 through 2010 to youth in a prospective cohort study, the Growing Up Today Study. The analysis included 5527 males aged 12 to 18 years in 1999 from across the United States who responded to the Growing Up Today Study questionnaires. Development of obesity and high levels of depressive symptoms and initiation of drug use and binge drinking at least monthly. From 1999 through 2011 in at least 1 study year, 9.2% of respondents reported high concerns with muscularity but no bulimic behaviors; 2.4%, high concerns with muscularity and use of supplements, growth hormone derivatives, or anabolic steroids to achieve their desired physique; 2.5%, high concerns with thinness but no bulimic behaviors; and 6.3%, high concerns with thinness and muscularity. For eating disorders, 0.8% had partial- or full-criteria bulimia nervosa or purging disorder and 2.9% had partial or full-criteria binge eating disorder but no association with the outcomes of interest. Infrequent binge eating or purging or overeating without a loss of control were reported by 31.0%. However, independent of age and body mass index, males with high concerns about thinness but not muscularity were more likely to develop high depressive symptoms (odds ratio, 2.72; 95% CI, 1.36-5.44). Males with high concerns about muscularity and thinness were more likely than their peers to use drugs (odds ratio, 2.13; 95% CI, 1.31-3.46), and males with high concerns about muscularity who used supplements and other products to enhance physique were more likely to start binge drinking frequently (2.06; 1.58-2.69) and using drugs (2.16; 1.49-3.11). High concerns with muscularity are relatively common among adolescent boys and young men. Males with these concerns who use potentially unhealthy products to improve their physique are at increased risk of adverse outcomes but may not be recognized by their health care providers as having a weight-related disorder because of the sex-specific presentation.

A qualitative examination of women's self-presentation and social physique anxiety during injury rehabilitation.

PubMed

Driediger, Molly V; McKay, Carly D; Hall, Craig R; Echlin, Paul S

2016-12-01

To understand women's self-presentation experiences in the rehabilitation setting, and their attitudes and preferences toward the social and physical features of the rehabilitation environment. Qualitative study. Outpatient physiotherapy clinic. Ten women (age 18 to 64) with high social physique anxiety (Social Physique Anxiety Scale score ≥25) referred for physiotherapy following acute injury. Semi-structured interviews were conducted prior to commencement of treatment, and again after a third treatment session. Participants experienced extensive self-presentational concerns that were intensified due to the nature of the physiotherapy environment. The women reported that their self-presentational anxiety did not diminish over time, and was related to others' negative perceptions regarding their physical appearance and inability to perform exercises as well as expected. The presence of men or younger women in the clinic was identified as a barrier to appointment attendance, along with open concept clinic settings, which were associated with the most potential for evaluation. Mirrors and windows in the physiotherapy clinic were highlighted as anxiety provoking. The women suggested that they would feel apprehensive about advocating for themselves if they felt uncomfortable with the area in which they were receiving treatment, and instead used avoidance coping strategies (e.g., hiding behind equipment, preventing eye contact) to manage their anxiety. Physique-anxious women experience extensive self-presentational concerns in the rehabilitation environment, which could affect treatment adherence. Modifying the treatment setting, providing protective self-presentational strategies such as positive self-talk, and open patient-therapist communication could be implemented to help mitigate these concerns. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

High-frequency Propagation through the Ionosphere from the Sura Heating Facility to the Orbiting CASSIOPE/e-POP Payload

NASA Astrophysics Data System (ADS)

James, H. G.; Frolov, V. L.; Padokhin, A. M.; Siefring, C. L.

2015-12-01

High-frequency pump waves have been transmitted from the Russian heating facility Sura to the Radio Receiver Instrument (RRI) in the e-POP payload on the Canadian small satellite CASSIOPE. This experiment has been carried out 24 times, under a variety of circumstances. In some cases, the ePOP VHF-UHF beacon CERTO was on, and ground receivers near Sura recorded total electron content. Subsequent tomographic processing has allowed the two-dimensional electron density distribution to be determined in the altitude-latitude space between Sura and CASSIOPE. We present some details from a night-time pass on 9 Sept. 2014 when the fixed pump frequency 4.3 MHz was slightly smaller than foF2 above Sura. This was an instance in which conversion between the O and Z cold plasma modes may have been required to achieve transmission. Explanation could be elaborated in terms of underdense, heater-created, field-aligned irregularities that are "artificial radio windows". The Sura heater radiation pattern maximum was tilted 12° south of the vertical, toward the terrestrial magnetic field axis, potentially enhancing the power transmitted through radio windows. The observations are interpreted in the light of competing concepts of transmission.

The protective role of general self-determination against 'thin ideal' media exposure on women's body image and eating-related concerns.

PubMed

Mask, Lisa; Blanchard, Céline M

2011-04-01

Women's responses to 'thin ideal' media pending their level of general self-determination (GSD) were examined. High and low GSD women (N = 99) viewed a 'thin physique salient' (TPS) video or a 'thin physique non-salient' (TPNS) video. Following exposure to the TPS video, perceptions of pressure from the media to be thin, body dissatisfaction, and concerns over quantity of food were greater for low but not high GSD women. However, high GSD women reported greater concerns over the quality of food they eat following exposure to the TPNS video. Prevention efforts aimed at enhancing GSD are discussed.

Club of Rome

ScienceCinema

None

2017-12-09

Le Club de Rome s'est fait connaître du grand public par la publication du premier ouvrage "Halte à la croissance" qui a fait l'object d'un débat, il y a 2 ans. Le Prof. Tinbergen a commencé par s'adonner à la physique, il est docteur en physique et très tôt il s'est tourné vers les problèmes sociaux économiques. Il est expert auprès des nombreux gouvernements et organisations internationales et il a vu ses travaux couronnés par le prix Nobel en 1969.

Role of Physique on Probability of Injury to the Low Back

NASA Astrophysics Data System (ADS)

Shaibani, Saami J.

2009-03-01

In a related study of the response of the upper and lower cervical spine[1], there was some correlation between a change in physique and the potential for injury to the neck during automotive events. A similar undertaking in this research on the lumbar spine and sacral spine revealed a much more marked effect, namely an increase in injury potential to the low back when weight is increased. Although there were some exceptions to this, the overall trend was distinct. This is perhaps to be expected when one considers that most additional weight at the same height tends to be located in the center or lower torso. However, it is first time in any comparable analysis of injury causation that there has been a more noticeable pattern for the low back than the neck. The latter was more pronounced with environment geometry, as seen when the height of the seat back was varied. Such changeability again reinforces previous findings that injury outcomes for individual patients cannot always be predicted by what happens in general. 1. http://meetings.aps.org/link/BAPS.2007.MAR.K1.2 (Role of physique on probability of injury to the neck).

The Social Physique Anxiety Scale: an example of the potential consequence of negatively worded items in factorial validity studies.

PubMed

Motl, R W; Conroy, D E; Horan, P M

2000-01-01

Social physique anxiety (SPA) based on Hart, Leary, and Rejeski's (1989) Social Physique Anxiety Scale (SPAS) was originally conceptualized to be a unidimensional construct. Empirical evidence on the factorial validity of the SPAS has been contradictory, yielding both one- and two-factor models. The two-factor model, which consists of separate factors associated with positively and negatively worded items, has stimulated an ongoing debate about the dimensionality and content of the SPAS. The present study employed confirmatory factor analysis (CFA) to examine whether the two-factor solution to the 12-item SPAS was substantively meaningful or a methodological artifact. Results of the CFAs, which were performed on responses from four different samples (Eklund, Kelley, and Wilson, 1997; Eklund, Mack, and Hart, 1996), supported the existence of a single substantive SPA factor underlying responses to the 12-item SPAS. There were, in addition, method effects associated with the negatively worded items that could be modeled to achieve good fit. Therefore, it was concluded that a single substantive factor and a non-substantive method effect primarily related to the negatively worded items best represented the 12-item SPAS.

Large-scale microwave anisotropy from gravitating seeds

NASA Technical Reports Server (NTRS)

Veeraraghavan, Shoba; Stebbins, Albert

1992-01-01

Topological defects could have seeded primordial inhomogeneities in cosmological matter. We examine the horizon-scale matter and geometry perturbations generated by such seeds in an expanding homogeneous and isotropic universe. Evolving particle horizons generally lead to perturbations around motionless seeds, even when there are compensating initial underdensities in the matter. We describe the pattern of the resulting large angular scale microwave anisotropy.

Subgrid Modeling of AGN-driven Turbulence in Galaxy Clusters

NASA Astrophysics Data System (ADS)

Scannapieco, Evan; Brüggen, Marcus

2008-10-01

Hot, underdense bubbles powered by active galactic nuclei (AGNs) are likely to play a key role in halting catastrophic cooling in the centers of cool-core galaxy clusters. We present three-dimensional simulations that capture the evolution of such bubbles, using an adaptive mesh hydrodynamic code, FLASH3, to which we have added a subgrid model of turbulence and mixing. While pure hydro simulations indicate that AGN bubbles are disrupted into resolution-dependent pockets of underdense gas, proper modeling of subgrid turbulence indicates that this is a poor approximation to a turbulent cascade that continues far beyond the resolution limit. Instead, Rayleigh-Taylor instabilities act to effectively mix the heated region with its surroundings, while at the same time preserving it as a coherent structure, consistent with observations. Thus, bubbles are transformed into hot clouds of mixed material as they move outward in the hydrostatic intracluster medium (ICM), much as large airbursts lead to a distinctive "mushroom cloud" structure as they rise in the hydrostatic atmosphere of Earth. Properly capturing the evolution of such clouds has important implications for many ICM properties. In particular, it significantly changes the impact of AGNs on the distribution of entropy and metals in cool-core clusters such as Perseus.

The dark matter of galaxy voids

NASA Astrophysics Data System (ADS)

Sutter, P. M.; Lavaux, Guilhem; Wandelt, Benjamin D.; Weinberg, David H.; Warren, Michael S.

2014-03-01

How do observed voids relate to the underlying dark matter distribution? To examine the spatial distribution of dark matter contained within voids identified in galaxy surveys, we apply Halo Occupation Distribution models representing sparsely and densely sampled galaxy surveys to a high-resolution N-body simulation. We compare these galaxy voids to voids found in the halo distribution, low-resolution dark matter and high-resolution dark matter. We find that voids at all scales in densely sampled surveys - and medium- to large-scale voids in sparse surveys - trace the same underdensities as dark matter, but they are larger in radius by ˜20 per cent, they have somewhat shallower density profiles and they have centres offset by ˜ 0.4Rv rms. However, in void-to-void comparison we find that shape estimators are less robust to sampling, and the largest voids in sparsely sampled surveys suffer fragmentation at their edges. We find that voids in galaxy surveys always correspond to underdensities in the dark matter, though the centres may be offset. When this offset is taken into account, we recover almost identical radial density profiles between galaxies and dark matter. All mock catalogues used in this work are available at http://www.cosmicvoids.net.

Fibrillation auriculaire et activité physique

PubMed Central

Bosomworth, N. John

2015-01-01

Résumé Objectif Examiner les données probantes portant sur les effets de divers niveaux d’activité physique sur l’incidence de fibrillation auriculaire (FA) dans la population générale et chez les athlètes d’endurance. Sources des données Une recherche a initialement été menée sur PubMed à l’aide des titres MeSH ou des mots-de-texte anglais (avec descripteur de zone de recherche TIAB [title and abstract]) atrial fibrillation et exercise ou physical activity ou athlet* ou sport*, sans filtre additionnel. Le système GRADE (grading of recommendations, assessment, development, and evaluation) a été utilisé pour tirer les conclusions au sujet de la qualité et du niveau de preuve. Sélection des études Aucune étude d’intervention n’est ressortie de la recherche. Les études d’observation ont alors été jugées acceptables et, bien que des études prospectives de cohortes à long terme de plus grande envergure auraient été préférables, des essais cas-témoins ou transversaux ont aussi été inclus dans cette révision. Synthèse Les données disponibles laissent croire à un lien proportionnel à la dose entre l’exercice plus intense et l’incidence réduite de FA chez les femmes. Il en va de même pour les hommes dont le niveau d’activité physique est de faible à modéré. Chez les hommes seulement, l’activité intense est associée à un risque accru de FA et ce, dans la plupart des études, mais pas la totalité d’entre elles. Ce risque est modéré, le rapport de risque instantané étant de 1,29 dans l’une des études de meilleure qualité. Le risque de FA chez la plupart des personnes régulièrement actives est plus faible que le risque observé dans la population sédentaire appariée. Conclusion La fibrillation auriculaire est probablement moins fréquente à mesure que le niveau d’activité physique augmente, la relation dose-réponse étant démontrable. À toutes les intensités, l’exercice doit être encouragé pour ses effets sur le bien-être physique et la réduction de la mortalité. Chez les hommes qui pratiquent des activités vigoureuses, les effets bénéfiques sur la FA pourraient disparaître et le risque pourrait surpasser celui observé dans la population sédentaire; cependant les données probantes à cet effet ne sont ni robustes ni constantes. Ces hommes devraient être mis au courant de cette hausse modeste du risque s’ils choisissent de poursuivre leurs activités physiques vigoureuses.

Progress in indirect and direct-drive planar experiments on hydrodynamic instabilities at the ablation front

DOE PAGES

Casner, A.; Masse, L.; Delorme, B.; ...

2014-12-01

Understanding and mitigating hydrodynamic instabilities and the fuel mix are the key elements for achieving ignition in Inertial Confinement Fusion. Cryogenic indirect-drive implosions on the National Ignition Facility have evidenced that the ablative Rayleigh-Taylor Instability (RTI) is a driver of the hot spot mix. This motivates the switch to a more flexible higher adiabat implosion design [O. A. Hurricane et al., Phys. Plasmas 21, 056313 (2014)]. The shell instability is also the main candidate for performance degradation in low-adiabat direct drive cryogenic implosions [Goncharov et al., Phys. Plasmas 21, 056315 (2014)]. This paper reviews recent results acquired in planar experimentsmore » performed on the OMEGA laser facility and devoted to the modeling and mitigation of hydrodynamic instabilities at the ablation front. In application to the indirect-drive scheme, we describe results obtained with a specific ablator composition such as the laminated ablator or a graded-dopant emulator. In application to the direct drive scheme, we discuss experiments devoted to the study of laser imprinted perturbations with special phase plates. The simulations of the Richtmyer-Meshkov phase reversal during the shock transit phase are challenging, and of crucial interest because this phase sets the seed of the RTI growth. Recent works were dedicated to increasing the accuracy of measurements of the phase inversion. We conclude by presenting a novel imprint mitigation mechanism based on the use of underdense foams. Lastly, the foams induce laser smoothing by parametric instabilities thus reducing the laser imprint on the CH foil.« less

Analysis of double stub tuner control stability in a many element phased array antenna with strong cross-coupling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallace, G. M.; Fitzgerald, E.; Johnson, D. K.

2014-02-12

Active stub tuning with a fast ferrite tuner (FFT) allows for the system to respond dynamically to changes in the plasma impedance such as during the L-H transition or edge localized modes (ELMs), and has greatly increased the effectiveness of fusion ion cyclotron range of frequency systems. A high power waveguide double-stub tuner is under development for use with the Alcator C-Mod lower hybrid current drive (LHCD) system. Exact impedance matching with a double-stub is possible for a single radiating element under most load conditions, with the reflection coefficient reduced from Γ to Γ{sup 2} in the “forbidden region.” Themore » relative phase shift between adjacent columns of a LHCD antenna is critical for control of the launched n{sub ∥} spectrum. Adding a double-stub tuning network will perturb the phase of the forward wave particularly if the unmatched reflection coefficient is high. This effect can be compensated by adjusting the phase of the low power microwave drive for each klystron amplifier. Cross-coupling of the reflected power between columns of the launcher must also be considered. The problem is simulated by cascading a scattering matrix for the plasma provided by a linear coupling model with the measured launcher scattering matrix and that of the FFTs. The solution is advanced in an iterative manner similar to the time-dependent behavior of the real system. System performance is presented under a range of edge density conditions from under-dense to over-dense and a range of launched n{sub ∥}.« less

Study of laser-generated debris free x-ray sources produced in a high-density linear Ar, Kr, Xe, Kr/Ar and Xe/Kr/Ar mixtures gas jets by 2 ω, sub-ps LLNL Titan laser

NASA Astrophysics Data System (ADS)

Kantsyrev, V. L.; Schultz, K. A.; Shlyaptseva, V. V.; Safronova, A. S.; Cooper, M. C.; Shrestha, I. K.; Petkov, E. E.; Stafford, A.; Moschella, J. J.; Schmidt-Petersen, M. T.; Butcher, C. J.; Kemp, G. E.; Andrews, S. D.; Fournier, K. B.

2016-10-01

The study of laser-generated debris-free x-ray sources in an underdense plasma produced in a high-density linear gas-puff jet was carried out at the LLNL Titan laser (2 ω, 45 J, sub-ps) with an intensity in the 10 um focal spot of 7 x 1019 W/cm2. A linear nozzle with a fast valve was used for the generation of a clusters/gas jet. X-ray diagnostics for the spectral region of 0.7 - 9 keV include: two spectrometers and pinhole cameras, and 3 groups of fast filtered detectors. Electron beams were measured with the EPPS magnetic spectrometer (>1 MeV) and Faraday cups (>72 keV). Spectralon/spectrometer devices were also used to measure absorption of laser radiation in the jets. New results were obtained on: anisotropic generation of x-rays (laser to x-ray conversion coefficient was >1%) and characteristics of laser-generated electron beams; evolution of x-ray generation with the location of the laser focus in a cluster-gas jet, and observations of a strong x-ray flash in some focusing regimes. Non-LTE kinetic modeling was used to estimate plasma parameters. UNR work supported by the DTRA Basic Research Award # HDTRA1-13-1-0033. Work at LLNL was performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

Electronegative Gas Thruster - Direct Thrust Measurement Project

NASA Technical Reports Server (NTRS)

Dankanich, John (Principal Investigator); Aanesland, Ane; Polzin, Kurt; Walker, Mitchell

2015-01-01

This effort is an international collaboration and academic partnership to mature an innovative electric propulsion (EP) thruster concept to TRL 3 through direct thrust measurement. The initial target application is for Small Satellites, but can be extended to higher power. The Plasma propulsion with Electronegative GASES (PEGASES) concept simplifies ion thruster operation, eliminates a neutralizer requirement and should yield longer life capabilities and lower cost implementation over conventional gridded ion engines. The basic proof-of concept has been demonstrated and matured to TRL 2 over the past several years by researchers at the Laboratoire de Physique des Plasma in France. Due to the low maturity of the innovation, there are currently no domestic investments in electronegative gas thrusters anywhere within NASA, industry or academia. The end product of this Center Innovation Fund (CIF) project will be a validation of the proof-of-concept, maturation to TRL 3 and technology assessment report to summarize the potential for the PEGASES concept to supplant the incumbent technology. Information exchange with the foreign national will be one-way with the exception of the test results. Those test results will first go through a standard public release ITAR/export control review, and the results will be presented in a public technical forum, and the results will be presented in a public technical forum.

Voids in Gravitational Instability Scenarios - Part One - Global Density and Velocity Fields in an Einstein - De-Sitter Universe

NASA Astrophysics Data System (ADS)

van de Weygaert, R.; van Kampen, E.

1993-07-01

The first results of an extensive study of the structure and dynamics of underdense regions in gravitational instability scenarios are presented. Instead of adopting spherically symmetric voids with some idealized initial density and velocity profile, underdense regions of a given size and depth, embedded in an initial density fluctuation field, are generated. In order to accomplish this in a consistent way, these initial conditions are set up by means of Bertschinger's constrained random field code. The generated particle samples of 64^3^ particles in a box of side 100 Mpc are followed into the non-linear regime by Bertschinger's PM N- body code. In this way we address the dependence of the structure and kinematics of the void both on the initial depth of the void and on the fluctuation field in which it is embedded. In particular, this study provides some understanding of how far fluctuations on small scales modify the dynamics of the large-scale void, and especially of how far the properties of small structures inside the void are affected by the global properties of the void. One of the conspicuous features of the initial density fields inside protovoids appears to be the existence of a `void hierarchy', with small voids embedded in larger voids. The survival of this hierarchy during the riot evolution of the void depends critically on the initial depth as well as on the clustering scenario involved. As well as presenting a qualitative discussion of the structure of underdense regions in initial density fields in different scenarios, and the results of simulations of the ensuing non-linear evolution, we concentrate in particular on a comparison of the global density and velocity fields in voids with predictions from linear theory as well as from the spherical outflow model. The relation between the initial linear depth, the resulting non-linear depth and the excess expansion velocities in voids is addressed. In addition, we find that, while near its centre a void becomes more and more spherical, the shape of its boundary is influenced to a large extent by the structures surrounding the void and therefore is generally more irregular. In this first study we concentrate on single voids in Einstein-de Sitter universes. The underdense regions considered are linear 1 σ_0_, 2 σ_0_ and 3 σ_0_ dips in fields that are Gaussian-smoothed on a scale of R_G_ = 10 h^-1^ Mpc, approximately half the size of the Bootes void. These regions are studied in terms of the Cold Dark Matter and Hot Dark Matter scenarios as well as in terms of the scale-free scenarios P(k) is proportional to k^0^, k^-1^ and k^-2^. The Hubble constant is taken to be H_0_ = 100 h km s^-1^ Mpc^-1^.

The role of physical activity, body mass index and maturity status in body-related perceptions and self-esteem of adolescents.

PubMed

Altıntaş, A; Aşçı, F H; Kin-İşler, A; Güven-Karahan, B; Kelecek, S; Özkan, A; Yılmaz, A; Kara, F M

2014-01-01

Adolescence represents a transitional period which is marked by physical, social and psychological changes. Changes in body shape and physical activity especially alter and shape the psychological well-being of adolescents. The purpose of this study was to determine the role of physical activity level, body mass index and maturity status in body-related perception and self-esteem of 11-18 years old adolescents. A total of 1012 adolescents participated in this study. The "Social Physique Anxiety Scale", "Body Image Satisfaction Scale", "Physical Self-Perception Profile for Children" and "Rosenberg Self-Esteem Inventory" were administered. Physical activity level and body mass index were assessed using the "Physical Activity Questionnaire" and "Bioelectrical Impedance Analyzer", respectively. Regression analysis indicated that body mass index was the only predictor of perceived body attractiveness, social physique anxiety, body image satisfaction and self-esteem for female adolescents. For male adolescents, both physical activity and body mass index were correlated with perceived body attractiveness and social physique anxiety. Pubertal status were not correlated with self-esteem and body-related perceptions for both males and females adolescents. In summary, body mass index and physical activity plays an important role in body-related perceptions and self-esteem of adolescents.

Social physique anxiety and physical activity behaviour of male and female exercisers.

PubMed

Portman, Robert M; Bradbury, Jane; Lewis, Kiara

2018-03-01

Despite females consistently reporting greater social physique anxiety (SPA), previous literature has yet to demonstrate whether SPA gender differences are linked to the way males and females perform physical activity. This study investigated an association between SPA and physical activity frequency, history of exercise, and physical activity intensity. Participants were represented by currently active users (N = 33 males; N = 31 females) of an on-campus university-run gym and completed a background physical activity questionnaire and the nine-item Social Physique Anxiety Scale. Participants also performed an exercise session at a self-selected level of exertion, with the intensity of each session measured via heart rate monitor. SPA was not associated with physical activity frequency, history of exercise (length of gym membership), or intensity for male and female exercisers. With respect to male participants, females reported higher SPA and a preference for performing higher intensity physical activity. Females and males also indicated a preference for performing aerobic and anaerobic physical activity respectively. Our findings suggest the experience of SPA does not deter body-conscious individuals from the performance of regular physical activity. Findings also suggest the discrepancy in male and female SPA is not linked to differences in the way physical activity is performed.

Purity and Cleanness of Aeorgel as a Cosmic Dust Capture Medium

NASA Technical Reports Server (NTRS)

Tsou, P.; Fleming, R.; Lindley, P.; Craig, A.; Blake, D.

1994-01-01

The capability for capturing micrometeoroids intact through laboratory simulations [Tsou 1988] and in space [Tsou 1993] in passive underdense silica aerogel offers a valuable tool for cosmic dust research. The integrity of the sample handling medium can substantially modify the integrity of the sample. Intact capture is a violent hypervelocity event: the integrity of the capturing medium can cause even greater modification of the sample.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vanderveld, R. Ali; Flanagan, Eanna E.; Wasserman, Ira

Recently, there have been suggestions that the Type Ia supernova data can be explained using only general relativity and cold dark matter with no dark energy. In 'Swiss cheese' models of the Universe, the standard Friedmann-Robertson-Walker picture is modified by the introduction of mass-compensating spherical inhomogeneities, typically described by the Lemaitre-Tolman-Bondi metric. If these inhomogeneities correspond to underdense cores surrounded by mass-compensating overdense shells, then they can modify the luminosity distance-redshift relation in a way that can mimic accelerated expansion. It has been argued that this effect could be large enough to explain the supernova data without introducing dark energymore » or modified gravity. We show that the large apparent acceleration seen in some models can be explained in terms of standard weak field gravitational lensing together with insufficient randomization of void locations. The underdense regions focus the light less than the homogeneous background, thus dimming supernovae in a way that can mimic the effects of acceleration. With insufficient randomization of the spatial location of the voids and of the lines of sight, coherent defocusing can lead to anomalously large demagnification effects. We show that a proper randomization of the voids and lines of sight reduces the effect to the point that it can no longer explain the supernova data.« less

Testing the conditional mass function of dark matter haloes against numerical N-body simulations

NASA Astrophysics Data System (ADS)

Tramonte, D.; Rubiño-Martín, J. A.; Betancort-Rijo, J.; Dalla Vecchia, C.

2017-05-01

We compare the predicted conditional mass function (CMF) of dark matter haloes from two theoretical prescriptions against numerical N-body simulations, both in overdense and underdense regions and at different Eulerian scales ranging from 5 to 30 h-1 Mpc. In particular, we consider in detail a locally implemented rescaling of the unconditional mass function (UMF) already discussed in the literature, and also a generalization of the standard rescaling method described in the extended Press-Schechter formalism. First, we test the consistency of these two rescalings by verifying the normalization of the CMF at different scales, and showing that none of the proposed cases provides a normalized CMF. In order to satisfy the normalization condition, we include a modification in the rescaling procedure. After this modification, the resulting CMF generally provides a better description of numerical results. We finally present an analytical fit to the ratio between the CMF and the UMF (also known as the matter-to-halo bias function) in underdense regions, which could be of special interest to speed up the computation of the halo abundance when studying void statistics. In this case, the CMF prescription based on the locally implemented rescaling provides a slightly better description of the numerical results when compared to the standard rescaling.

Probing supervoids with weak lensing

NASA Astrophysics Data System (ADS)

Higuchi, Yuichi; Inoue, Kaiki Taro

2018-05-01

The cosmic microwave background (CMB) has non-Gaussian features in the temperature fluctuations. An anomalous cold spot surrounded with a hot ring, called the Cold Spot, is one of such features. If a large underdense region (supervoid) resides towards the Cold Spot, we would be able to detect a systematic shape distortion in the images of background source galaxies via weak lensing effect. In order to estimate the detectability of such signals, we used the data of N-body simulations to simulate full-sky ray-tracing of source galaxies. We searched for a most prominent underdense region using the simulated convergence maps smoothed at a scale of 20° and obtained tangential shears around it. The lensing signal expected in a concordant Λ cold dark matter model can be detected at a signal-to-noise ratio S/N ˜ 3. If a supervoid with a radius of ˜200 h-1 Mpc and a density contrast δ0 ˜ -0.3 at the centre resides at a redshift z ˜ 0.2, on-going and near-future weak gravitational lensing surveys would detect a lensing signal with S/N ≳ 4 without resorting to stacking. From the tangential shear profile, we can obtain a constraint on the projected mass distribution of the supervoid.

Sura heating facility transmissions to the CASSIOPE/e-POP satellite

NASA Astrophysics Data System (ADS)

James, H. G.; Frolov, V. L.; Andreeva, E. S.; Padokhin, A. M.; Siefring, C. L.

2017-02-01

Throughout a nighttime pass of the CASSIOPE satellite at an altitude of about 1300 km above the Sura heating facility, transmission of O-mode radiation from Sura to the enhanced Polar Outflow Probe (e-POP) Radio Receiver Instrument on CASSIOPE was maintained. Also, during this pass, continuous VHF/UHF transmission from the e-POP Coherent Electromagnetic Radio Tomography radio beacon to three coordinated ground receivers in the Sura vicinity was achieved. Tomography of the VHF/UHF received wave data based on total electron content permitted the two-dimensional distribution of ionospheric ambient electron plasma frequency fpe to be determined in the latitude-altitude space between Sura and CASSIOPE. The foF2 values about 0.1 MHz above the Sura pump frequency of 4.3 MHz were measured by the tomography. We examine the question of whether the observations can be explained on the basis of classic propagation in a smooth ionosphere. Tracing of rays from Sura toward CASSIOPE orbital locations finds most rays reflected away from the topside by the patchy ionospheric structure in bottomside fpe. It is concluded that O-mode ducting in underdense field-aligned irregularities is responsible for maintaining the transionospheric transmission across the 2 min pass. O- to Z-mode "radio-window" conversion in the F region bottomside is not required to explain these data.

Inertial confinement fusion and fast ignitor studies

NASA Astrophysics Data System (ADS)

Willi, O.; Barringer, L.; Bell, A.; Borghesi, M.; Davies, J.; Gaillard, R.; Iwase, A.; MacKinnon, A.; Malka, G.; Meyer, C.; Nuruzzaman, S.; Taylor, R.; Vickers, C.; Hoarty, D.; Gobby, P.; Johnson, R.; Watt, R. G.; Blanchot, N.; Canaud, B.; Croso, H.; Meyer, B.; Miquel, J. L.; Reverdin, C.; Pukhov, A.; Meyer-ter-Vehn, J.

2000-03-01

Laser imprinting has been studied and, in particular, saturation of areal density perturbations induced by near single mode laser imprinting was observed. Several issues important for the foam buffered direct drive scheme have been investigated. These studies included measurements of the absolute levels of stimulated Brillouin and Raman scattering observed from laser irradiated low density foam targets, either bare or overcoated with a thin layer of gold. A novel scheme is proposed to increase the pressure in indirectly driven targets. By heating a foam supersonically that is attached to a solid target the pressure generated is not only the ablation pressure but also the combined pressure due to ablation at the foam-foil interface and the heated foam material. Planar brominated plastic foil targets overcoated with a low density foam were irradiated by a soft X ray pulse. The pressure was obtained by comparing the rear side trajectory of the driven target observed by soft X ray radiography with one dimensional radiation hydrodynamic simulations. Observations were also carried out of the transition from supersonic to subsonic propagation of an ionization front in low density chlorinated foam targets irradiated by an intense soft X ray pulse. The diagnostic for these measurements was K shell point projection absorption spectroscopy. In the fast ignitor area the channelling and guiding of picosecond laser pulses through underdense plasmas, preformed density channels and microtubes were investigated. It was observed that a large fraction of the incident laser energy can be propagated. Megagauss magnetic fields were measured, with a polarimetric technique, during and after propagation of intense picosecond pulses in preionized plasmas. Two types of toroidal fields, of opposite orientation, were detected. In addition, the production and propagation of an electron beam through solid glass targets irradiated at intensities above 1019W/cm2 were observed using optical probing techniques.

Optimization of the combined proton acceleration regime with a target composition scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, W. P.; Graduate School, China Academy of Engineering Physics, Beijing 100088; Li, B. W., E-mail: li-baiwen@iapcm.ac.cn

A target composition scheme to optimize the combined proton acceleration regime is presented and verified by two-dimensional particle-in-cell simulations by using an ultra-intense circularly polarized (CP) laser pulse irradiating an overdense hydrocarbon (CH) target, instead of a pure hydrogen (H) one. The combined acceleration regime is a two-stage proton acceleration scheme combining the radiation pressure dominated acceleration (RPDA) stage and the laser wakefield acceleration (LWFA) stage sequentially together. Protons get pre-accelerated in the first stage when an ultra-intense CP laser pulse irradiating an overdense CH target. The wakefield is driven by the laser pulse after penetrating through the overdense CHmore » target and propagating in the underdense tritium plasma gas. With the pre-accelerate stage, protons can now get trapped in the wakefield and accelerated to much higher energy by LWFA. Finally, protons with higher energies (from about 20 GeV up to about 30 GeV) and lower energy spreads (from about 18% down to about 5% in full-width at half-maximum, or FWHM) are generated, as compared to the use of a pure H target. It is because protons can be more stably pre-accelerated in the first RPDA stage when using CH targets. With the increase of the carbon-to-hydrogen density ratio, the energy spread is lower and the maximum proton energy is higher. It also shows that for the same laser intensity around 10{sup 22} W cm{sup −2}, using the CH target will lead to a higher proton energy, as compared to the use of a pure H target. Additionally, proton energy can be further increased by employing a longitudinally negative gradient of a background plasma density.« less

Lung function in children in relation to ethnicity, physique and socio-economic factors

PubMed Central

Lum, Sooky; Bountziouka, Vassiliki; Sonnappa, Samatha; Wade, Angie; Cole, Tim J; Harding, Seeromanie; Wells, Jonathan CK; Griffiths, Chris; Treleaven, Philip; Bonner, Rachel; Kirkby, Jane; Lee, Simon; Raywood, Emma; Legg, Sarah; Sears, Dave; Cottam, Philippa; Feyeraband, Colin; Stocks, Janet

2015-01-01

Question Can ethnic differences in spirometry be attributed to differences in physique and socio-economic factors? Methods Assessments were undertaken in 2171 London primary school-children on two occasions a year apart whenever possible, as part of the Size and Lung function In Children study. Measurements included spirometry, detailed anthropometry, 3-D photonic scanning for regional body shape, body composition, information on ethnic ancestry, birth and respiratory history, socio-economic circumstances and tobacco smoke exposure. Results Technically acceptable spirometry was obtained from 1901 children (mean age: 8.3yrs (range: 5.2-11.8yrs), 46% boys, 35% White; 29% Black-African origin; 24% South-Asian; 12% Other/mixed) on 2767 test occasions. After adjusting for sex, age and height, FEV1 was 1.32, 0.89 and 0.51 z-score units lower in Black, South-Asian and Other ethnicity children respectively, when compared with White children, with similar decrements for FVC (p<0.001 for all). Although further adjustment for sitting height and chest width reduced differences attributable to ethnicity by up to 16%, significant differences persisted after adjusting for all potential determinants including socio-economic circumstances. Answer Ethnic differences in spirometric lung function persist despite adjusting for a wide range of potential determinants, including body physique and socio-economic circumstances, emphasising the need to use ethnic-specific equations when interpreting results. PMID:26493801

Le syndrome des enfants battus: aspects cliniques et radiologiques

PubMed Central

Jlalia, Zied; Znaigui, Talel; Smida, Mahmoud

2016-01-01

La maltraitance physique des enfants ou le syndrome des enfants battus est responsable de plus de 75.000 décès par an en France. Ce problème de santé publique reste sous diagnostiqué en Tunisie et dans le monde. Le chemin a été laborieux pour la reconnaissance du syndrome des enfants battus dans certaines sociétés même occidentales. Nous avons voulus exposer ce problème aux praticiens afin qu'il soit mieux diagnostiqué et pris en charge. La maltraitance physique des enfants est appelée à tort syndrome de Silverman qui ne regroupe en fait que les lésions squelettiques chez ces enfants tels que les fractures. Mots clés: Fracture, maltraitance, enfant, neuro-radiologie PMID:27642408

Foreword

NASA Astrophysics Data System (ADS)

Villain, Jacques

2017-01-01

The present issue of the Comptes Rendus Physique aims to provide the scientific reader with an opportunity to become acquainted with current scientific trends that have been distinguished by prizes of the French Academy of Sciences.

Interaction of Intense Lasers with Plasmas

NASA Astrophysics Data System (ADS)

Shvets, Gennady

1995-01-01

This thesis addresses two important topics in nonlinear laser plasma physics: the interaction of intense lasers with a non thermal homogeneous plasma, the excitation of laser wakefields in hollow plasma channels, and the stability of channel guided propagation of laser pulses. In the first half of this thesis a new theoretical approach to the nonlinear interaction of intense laser pulses with underdense plasmas is developed. Unlike previous treatments, this theory is three-dimensional, relativistically covariant, and does not assume that a<<1, where a=eA/mc^2 is a dimensionless vector potential. This formalism borrows the diagrammatic techniques from quantum field theory, yet remains classical. This classical field theory, which treats cold plasma as a relativistic field interacting with the electromagnetic fields, introduces an artificial length scale which is smaller than any physically relevant spatial scale. By adopting a special (Arnowitt -Fickler) gauge, electromagnetic waves in a cold relativistic plasma are separated into "photons" and "plasmons" which are the relativistic extensions of electrostatic and electromagnetic waves in a cold stationary plasma. The field-theoretical formalism is applied to a variety of nonlinear problems including harmonic generation, parametric instabilities, and nonlinear corrections to the index of refraction. For the first time the rate of the second harmonic emission from a homogeneous plasma is calculated and its dependence on the polarization of the incident radiation is studied. An experimental check of this calculation is suggested, based on the predicted non-linear polarization rotation (the second harmonic is emitted polarized perpendicularly to polarization of the incident signal). The concept of renormalization is applied to the plasma and electromagnetic radiation (photons and plasmons). To the lowest order, this corresponds to relativistically correcting the electron mass for its oscillation in an intense EM field and to replacing the vacuum dispersion relation by the usual relativistic plasma dispersion relation. This renormalization procedure is then carried to higher order in epsilon=omega_sp{p} {2}a^2/[(1+a^2/2)^ {3/2}omega^2]. This yields the nonlinear modification of the index of refraction of a strong electromagnetic wave and the dispersion of a weak probe in the presence of the wave. In the second part of this thesis the stability of short laser pulses propagating through parabolic channels and the wake excitation of hollow plasma channels are studied. The stability of a channel guided short laser pulse propagation is analyzed for the first time. Perturbations to the laser pulse are shown to modify the ponderomotive pressure, which distorts the dielectric properties of the plasma channel. The channel perturbation then further distorts the laser pulse. A set of coupled mode equations is derived, and a matrix dispersion relation is obtained analytically. The ponderomotive excitation of wakefields in a hollow plasma channel by an intense laser pulse is studied analytically. An important finding is that the resonant absorption in the channel wall dissipates the accelerating wake, thereby introducing a finite quality factor of the hollow plasma channel and reducing the number of electron bunches that can be accelerated in the wake of a single laser pulse. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.) (Abstract shortened by UMI.).

History without time: Buffon's natural history as a nonmathematical physique.

PubMed

Hoquet, Thierry

2010-03-01

While "natural history" is practically synonymous with the name of Buffon, the term itself has been otherwise overlooked by historians of science. This essay attempts to address this omission by investigating the meanings of "physique," "natural philosophy," and "history," among other terms, with the purpose of understanding Buffon's actual objectives. It also shows that Buffon never claimed to be a Newtonian and should not be considered as such; the goal is to provide a historical analysis that resituates Buffon's thought within his own era. This is done, primarily, by eschewing the often-studied question of time in Buffon. Instead, this study examines the nontemporal meanings of the word "history" within the naturalist's theory and method. The title of his Natural History is examined both as an indicator of the kind of science that Buffon was hoping to achieve and as a source of great misinterpretation among his peers. Unlike Buffon, many of his contemporaries actually envisioned the study of nature from a Baconian perspective where history was restricted to the mere collection of facts and where philosophy, which was the implicit and ultimate goal of studying nature, was seen, at least for the present, as unrealizable. Buffon confronts this tendency insofar as his Histoire naturelle claims to be the real physique that, along with describing nature, also sought to identify general laws and provide clear insight into what true knowledge of nature is or should be. According to Buffon, history (both natural and civil) is not analogous to mathematics; it is a nonmathematical method whose scope encompasses both nature and society. This methodological stance gives rise to the "physicization" of certain moral concepts--a gesture that was interpreted by his contemporaries as Epicurean and atheist. In addition, Buffon reduces a number of metaphysically tainted historical concepts (e.g., antediluvian monuments) to objects of physical analysis, thereby confronting the very foundation of natural theology. In Buffon, as this essay makes clear, natural history is paving the way for a new physique (science of natural beings), independent from mathematics and from God, that treats naturalia in a philosophical and "historical" manner that is not necessarily "temporal."

Voids and constraints on nonlinear clustering of galaxies

NASA Technical Reports Server (NTRS)

Vogeley, Michael S.; Geller, Margaret J.; Park, Changbom; Huchra, John P.

1994-01-01

Void statistics of the galaxy distribution in the Center for Astrophysics Redshift Survey provide strong constraints on galaxy clustering in the nonlinear regime, i.e., on scales R equal to or less than 10/h Mpc. Computation of high-order moments of the galaxy distribution requires a sample that (1) densely traces the large-scale structure and (2) covers sufficient volume to obtain good statistics. The CfA redshift survey densely samples structure on scales equal to or less than 10/h Mpc and has sufficient depth and angular coverage to approach a fair sample on these scales. In the nonlinear regime, the void probability function (VPF) for CfA samples exhibits apparent agreement with hierarchical scaling (such scaling implies that the N-point correlation functions for N greater than 2 depend only on pairwise products of the two-point function xi(r)) However, simulations of cosmological models show that this scaling in redshift space does not necessarily imply such scaling in real space, even in the nonlinear regime; peculiar velocities cause distortions which can yield erroneous agreement with hierarchical scaling. The underdensity probability measures the frequency of 'voids' with density rho less than 0.2 -/rho. This statistic reveals a paucity of very bright galaxies (L greater than L asterisk) in the 'voids.' Underdensities are equal to or greater than 2 sigma more frequent in bright galaxy samples than in samples that include fainter galaxies. Comparison of void statistics of CfA samples with simulations of a range of cosmological models favors models with Gaussian primordial fluctuations and Cold Dark Matter (CDM)-like initial power spectra. Biased models tend to produce voids that are too empty. We also compare these data with three specific models of the Cold Dark Matter cosmogony: an unbiased, open universe CDM model (omega = 0.4, h = 0.5) provides a good match to the VPF of the CfA samples. Biasing of the galaxy distribution in the 'standard' CDM model (omega = 1, b = 1.5; see below for definitions) and nonzero cosmological constant CDM model (omega = 0.4, h = 0.6 lambda(sub 0) = 0.6, b = 1.3) produce voids that are too empty. All three simulations match the observed VPF and underdensity probability for samples of very bright (M less than M asterisk = -19.2) galaxies, but produce voids that are too empty when compared with samples that include fainter galaxies.

Ionospheric Modification from Under-Dense Heating by High-Power HF Transmitter

DTIC Science & Technology

2011-03-03

Auroral Research Program ( HAARP ) is a HF transmitter, which delivers 0.36 to 3.6 GW effective isotropic radiated powers (F.IRP) for the radiation...dense heating, the EIRP of the HAARP heater can be increased significantly by increasing the heater frequency. With higher heater frequency, the loss...1304 local time) and on 13 April from 0812 to 0844 UTC (0012 to 0044 local time), using the HAARP transmitter facility at Gakona, AK, at full power

Cosmic void clumps

NASA Astrophysics Data System (ADS)

Lares, M.; Luparello, H. E.; Garcia Lambas, D.; Ruiz, A. N.; Ceccarelli, L.; Paz, D.

2017-10-01

Cosmic voids are of great interest given their relation to the large scale distribution of mass and the way they trace cosmic flows shaping the cosmic web. Here we show that the distribution of voids has, in consonance with the distribution of mass, a characteristic scale at which void pairs are preferentially located. We identify clumps of voids with similar environments and use them to define second order underdensities. Also, we characterize its properties and analyze its impact on the cosmic microwave background.

Distinguishing models of reionization using future radio observations of 21-cm 1-point statistics

NASA Astrophysics Data System (ADS)

Watkinson, C. A.; Pritchard, J. R.

2014-10-01

We explore the impact of reionization topology on 21-cm statistics. Four reionization models are presented which emulate large ionized bubbles around overdense regions (21CMFAST/global-inside-out), small ionized bubbles in overdense regions (local-inside-out), large ionized bubbles around underdense regions (global-outside-in) and small ionized bubbles around underdense regions (local-outside-in). We show that first generation instruments might struggle to distinguish global models using the shape of the power spectrum alone. All instruments considered are capable of breaking this degeneracy with the variance, which is higher in outside-in models. Global models can also be distinguished at small scales from a boost in the power spectrum from a positive correlation between the density and neutral-fraction fields in outside-in models. Negative skewness is found to be unique to inside-out models and we find that pre-Square Kilometre Array (SKA) instruments could detect this feature in maps smoothed to reduce noise errors. The early, mid- and late phases of reionization imprint signatures in the brightness-temperature moments, we examine their model dependence and find pre-SKA instruments capable of exploiting these timing constraints in smoothed maps. The dimensional skewness is introduced and is shown to have stronger signatures of the early and mid-phase timing if the inside-out scenario is correct.

Drive for leanness and health-related behavior within a social/cultural perspective.

PubMed

Tod, David; Edwards, Christian; Hall, Gareth

2013-09-01

We examined relationships between drive for leanness and perceived media pressure to change appearance, internalization of an ideal physique, exercise frequency, and dieting. Men and women (N=353) completed the Drive for Leanness Scale, the Sociocultural Attitudes Toward Appearance Questionnaire-3, the Eating Attitudes Test-26, and a demographic inventory. Drive for leanness was significantly correlated with athletic internalization (.52), pressure to attain an ideal physique (.25), exercise frequency (.36), and dieting (.25). Structural equation modeling revealed a good fitting model (χ(2)=2.85, p<.241; CFI=.99; NNFI=.98; RMSEA=.04; SRMR=.02) with internalization predicting drive for leanness, which in turn predicted dieting and exercise. Results reveal social/cultural theory helps enhance the understanding of the drive for leanness and its relationship with health-related behavior. Copyright © 2013 Elsevier Ltd. All rights reserved.

Promotion of Healthy Weight-Control Practices in Young Athletes.

PubMed

Carl, Rebecca L; Johnson, Miriam D; Martin, Thomas J

2017-09-01

Children and adolescents may participate in sports that favor a particular body type. Some sports, such as gymnastics, dance, and distance running, emphasize a slim or lean physique for aesthetic or performance reasons. Participants in weight-class sports, such as wrestling and martial arts, may attempt weight loss so they can compete at a lower weight class. Other sports, such as football and bodybuilding, highlight a muscular physique; young athletes engaged in these sports may desire to gain weight and muscle mass. This clinical report describes unhealthy methods of weight loss and gain as well as policies and approaches used to curb these practices. The report also reviews healthy strategies for weight loss and weight gain and provides recommendations for pediatricians on how to promote healthy weight control in young athletes. Copyright © 2017 by the American Academy of Pediatrics.

A Self-determination Theory approach to the study of body image concerns, self-presentation and self-perceptions in a sample of aerobic instructors.

PubMed

Thøgersen-Ntoumani, Cecilie; Ntoumanis, Nikos

2007-03-01

This study examined motivational predictors of body image concerns, self-presentation and self-perceptions using Self-determination Theory as a guiding framework. Aerobic instructors (N = 149) completed questionnaires measuring general need satisfaction, exercise motivational regulations, body image concerns, social physique anxiety and self-perceptions. Introjected regulation predicted all outcome variables in the expected direction. Intrinsic motivation positively predicted physical self-worth. Further, autonomy need satisfaction negatively predicted body image concerns. Finally, differences existed in need satisfaction, introjected regulation, self-perceptions and social physique anxiety between those at risk of developing eating disorders and those not at risk. The results underline the importance of overall and exercise-specific feelings of self-determination in dealing with body image concerns and low self-perceptions of aerobics instructors.

The effect of labour on somatotype of males during the adolescent growth period.

PubMed

Ozener, B; Duyar, I

2008-01-01

Although the effect of labour and physical stress on the height and weight of growing children is relatively well known, rather limited information concerning the influences of the work environment on the physique of working children and adolescents is available. The purpose of this study was to increase our knowledge of the effects of mechanical stress on the human physique via somatotype during the adolescent growth period. Anthropometric measurements of 509 male apprentices aged 13.50-18.49 years and measurements of 451 nonworking youth (control group) of the same age group were taken. The members of both groups were from the lower socioeconomic strata and had similar living conditions. The apprentices were working an average of 11h per day in vocations requiring intense physical effort. The subjects were somatotyped using the Heath-Carter anthropometric protocol. The overall mean somatotypes were 2.3-4.4-3.3 for working adolescents, and 2.5-3.9-3.6 for the nonworking controls. A one-way multivariate analysis of variance (MANOVA) indicated significant differences between the groups. Working adolescents were more mesomorphic and less ectomorphic than their nonworking peers. In both groups, endomorphy decreased with age up to age 15; then remained stable for the labourers but increased for the nonworking peers. In both groups, mesomorphy was stable, but decreased with ectomorphy. These results indicate that physical stress not only causes retardation in linear growth, but also produces changes in human physique during the growth period.

Body size and physique among Canadians of First Nation and European ancestry.

PubMed

Katzmarzyk, P T; Malina, R M

1999-02-01

The purpose of this study was to compare body size and physique among Canadians of Aboriginal (First Nation [FN]) and European ancestry (EA) from the northern Ontario communities of Temagami and Bear Island. The sample consisted of 130 FN and 494 EA participants including adults (20-75 years: 214 men, 234 women) and youth (5-19 years: 97 boys, 79 girls). Indicators of body size and physique included stature, the sitting height-to-stature ratio (SSR), body mass, BMI, estimated upper-arm muscle area, biacromial, bicristal, biepicondylar, and bicondylar breadths, and the Heath-Carter anthropometric somatotype (endomorphy, mesomorphy, and ectomorphy). There were few differences in body size between FN and EA, with the exception of adult females. Adult FN females were significantly heavier and had greater bone breadths than EA women (P < 0.001). On the other hand, somatotype differed significantly between EA and FN by age and sex, except for 5-19-year-old females. Among boys and men, FN had greater endomorphy (P < 0.03), whereas FN men also had lower ectomorphy (P < 0.01). Among women, FN were significantly more endomorphic and mesomorphic and less ectomorphic (P < 0.001). Although results for 5-19-year-old females were not significant, they were in the same direction as the other groups (greater endomorphy). Forward stepwise discriminant function analyses indicated that endomorphy was the most important discriminator between FN and EA by age and sex.

La réfrigération des grandes machines supraconductrices

NASA Astrophysics Data System (ADS)

Gistau, Guy

1991-02-01

The large scale superconducting devices which are now in operation for deviation of heavy particles, acceleration of light particles or plasma confinement need very large powers of refrigeration. After a short survewing of the different functions of refrigerators and the special requirements for large units, the paper describes some existing or envisaged cooling systems which have an equivalent cooling power in the range of 5 kW at 4.5 K. Les grands appareils de physique utilisant les supraconducteurs demandent des puissances cryogéniques de plus en plus importantes. Après un examen des fonctions élémentaires assurées par un réfrigérateur liées au cahier des charges spécifique à chaque utilisation, les spécificités des grosses unités de réfrigération (fiabilité, efficacité, flexibilité, automatisme) sont mises en évidence. Les solutions proposées dans plusieurs grands projets nécessitant des puissances froides supérieures à 5 kW à 4,5 K sont discutées.

Le satellite Encelade source d'ions N+ dans la magnétosphère de Saturne

NASA Astrophysics Data System (ADS)

Bouhram, Mehdi; Berthelier, Jean-Jacques; Illiano, Jean-Marie; Smith, Howard T.; Sittler, Edward C.; Crary, Frank J.; Young, Dave T.

2005-12-01

xml:lang="fr">RésuméLe premier passage de la sonde Cassini dans l'environnement de Saturne, au dessus de l'anneau E, a mis en évidence l'existence d'un plasma composé d'un mélange d'ions issus des produits de l'eau (H+, O+, OH+, H2O+) avec une faible composante en ions N+ (3 %). A partir d'un modèle simple du transport des ions dans la magnétosphère, nous montrons que la source de ces ions N+ coïncide avec le satellite Encelade. Un tel résultat peut s'expliquer par la présence de composés volatiles tels que l'ammoniac NH3 sur ce satellite de glace, supposé encore actif géologiquement, ou par la présence d'ions N+ d'origine externe préalablement implantés sur sa surface. Pour citer cet article : M. Bouhram et al., C. R. Physique 6 (2005).

Polar cap ion beams during periods of northward IMF: Cluster statistical results

NASA Astrophysics Data System (ADS)

Maggiolo, R.; Echim, M.; de Keyser, J.; Fontaine, D.; Jacquey, C.; Dandouras, I.

2011-05-01

Above the polar caps and during prolonged periods of northward IMF, the Cluster satellites detect upward accelerated ion beams with energies up to a few keV. They are associated with converging electric field structures indicating that the acceleration is caused by a quasi-static field-aligned electric field that can extend to altitudes higher than 7 RE (Maggiolo et al., 2006; Teste et al., 2007). Using the AMDA science analysis service provided by the Centre de Données de la Physique des Plasmas, we have been able to extract about 200 events of accelerated upgoing ion beams above the polar caps from the Cluster database. Most of these observations are taken at altitudes lower than 7 RE and in the Northern Hemisphere. We investigate the statistical properties of these ion beams. We analyze their geometry, the properties of the plasma populations and of the electric field inside and around the beams, as well as their dependence on solar wind and IMF conditions. We show that ~40 % of the ion beams are collocated with a relatively hot and isotropic plasma population. The density and temperature of the isotropic population are highly variable but suggest that this plasma originates from the plasma sheet. The ion beam properties do not change significantly when the isotropic, hot background population is present. Furthermore, during one single polar cap crossing by Cluster it is possible to detect upgoing ion beams both with and without an accompanying isotropic component. The analysis of the variation of the IMF BZ component prior to the detection of the beams indicates that the delay between a northward/southward turning of IMF and the appearance/disappearance of the beams is respectively ~2 h and 20 min. The observed electrodynamic characteristics of high altitude polar cap ion beams suggest that they are closely connected to polar cap auroral arcs. We discuss the implications of these Cluster observations above the polar cap on the magnetospheric dynamics and configuration during prolonged periods of northward IMF.

Direct-drive Energetics of laser-Heated Foam Liners for Hohlraums

NASA Astrophysics Data System (ADS)

Moore, Alastair; Thomas, Cliff; Baker, Kevin; Morton, John; Baumann, Ted; Biener, Monika; Bhandarkar, Suhas; Hinkel, Denise; Jones, Oggie; Meezan, Nathan; Moody, John; Nikroo, Abbas; Rosen, Mordy; Hsing, Warren

2016-10-01

Lining the walls of a high-Z hohlraum cavity with a low-density foam is predicted to mitigate the challenge presented by hohlraum wall expansion. Once heated, wall material quickly fills the cavity and can impede laser beam propagation. To avoid this, ignition hohlraums are typically filled with a gas or irradiated with a short (< 10 ns) laser pulse. A gas-fill has the disadvantage that it can cause laser plasma instabilities (LPI), while a short laser pulse limits the design space to reach low-adiabat implosions. Foam-liners offer a potential route to reduce wall motion in a low gas-fill hohlraum with little LPI. Results from quasi 1-D experiments performed at the NIF are presented These characterize the x-ray conversion efficiency, backscattered laser energy and heat propagation in a 250 μm thick Ta2O5 or ZnO foam-liners spanning a range of densities from underdense to overdense, when irradiated at up to 4.9 x 1014 W/cm2 is incident on a planar foam sample, backed by a Au foil and generates a radiation temperature of up to 240eV - conditions equivalent to a single outer cone beam-spot in an ignition hohlraum. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Joining the yellow hub: Uses of the Simple Application Messaging Protocol in Space Physics analysis tools

NASA Astrophysics Data System (ADS)

Génot, V.; André, N.; Cecconi, B.; Bouchemit, M.; Budnik, E.; Bourrel, N.; Gangloff, M.; Dufourg, N.; Hess, S.; Modolo, R.; Renard, B.; Lormant, N.; Beigbeder, L.; Popescu, D.; Toniutti, J.-P.

2014-11-01

The interest for data communication between analysis tools in planetary sciences and space physics is illustrated in this paper via several examples of the uses of SAMP. The Simple Application Messaging Protocol is developed in the frame of the IVOA from an earlier protocol called PLASTIC. SAMP enables easy communication and interoperability between astronomy software, stand-alone and web-based; it is now increasingly adopted by the planetary sciences and space physics community. Its attractiveness is based, on one hand, on the use of common file formats for exchange and, on the other hand, on established messaging models. Examples of uses at the CDPP and elsewhere are presented. The CDPP (Centre de Données de la Physique des Plasmas, http://cdpp.eu/), the French data center for plasma physics, is engaged for more than a decade in the archiving and dissemination of data products from space missions and ground observatories. Besides these activities, the CDPP developed services like AMDA (Automated Multi Dataset Analysis, http://amda.cdpp.eu/) which enables in depth analysis of large amount of data through dedicated functionalities such as: visualization, conditional search and cataloging. Besides AMDA, the 3DView (http://3dview.cdpp.eu/) tool provides immersive visualizations and is further developed to include simulation and observational data. These tools and their interactions with each other, notably via SAMP, are presented via science cases of interest to planetary sciences and space physics communities.

Evulvalution: the portrayal of women's external genitalia and physique across time and the current barbie doll ideals.

PubMed

Schick, Vanessa R; Rima, Brandi N; Calabrese, Sarah K

2011-01-01

Media images of the female body commonly represent reigning appearance ideals of the era in which they are published. To date, limited documentation of the genital appearance ideals in mainstream media exists. Analysis 1 sought to describe genital appearance ideals (i.e., mons pubis and labia majora visibility, labia minora size and color, and pubic hair style) and general physique ideals (i.e., hip, waist, and bust size, height, weight, and body mass index [BMI]) across time based on 647 Playboy Magazine centerfolds published between 1953 and 2007. Analysis 2 focused exclusively on the genital appearance ideals embodied by models in 185 Playboy photographs published between 2007 and 2008. Taken together, results suggest the perpetuation of a "Barbie Doll" ideal characterized by a low BMI, narrow hips, a prominent bust, and hairless, undefined genitalia resembling those of a prepubescent female.

Physical appearance concerns are uniquely associated with the severity of steroid dependence and depression in anabolic-androgenic steroid users.

PubMed

Griffiths, Scott; Jacka, Brendan; Degenhardt, Louisa; Murray, Stuart B; Larance, Briony

2018-02-27

Emerging research suggests that the sub-population of anabolic-androgenic steroid (AAS) users who experience physical appearance concerns may suffer greater psychological dysfunction than other sub-populations, including users with athletic or occupational concerns. Thus, among current AAS users, we sought to determine whether, and to what extent, social physique anxiety-an established measure of appearance concern-was associated with psychological dysfunction. Interviews were conducted with a sample of 74 male AAS users living in Australia. Users completed self-report instruments of the severity of AAS dependence, depression, hazardous and risky drinking, use of non-AAS illicit drugs, psychological side-effects due to AAS use and abnormal test results due to AAS use. Multivariate analyses revealed that greater social physique anxiety was uniquely associated with more severe symptoms of both AAS dependence and depression. Moreover, the effect size of these relationships was large. Social physique anxiety was not associated with hazardous or risky drinking, non-AAS illicit drug use, psychological side-effects or abnormal test results. Limitations notwithstanding, the study is consistent with the notion that AAS users who experience appearance concerns are at heightened risk of co-morbid psychological dysfunction. Given trends indicating an increase in the prevalence of AAS use in Australia and elsewhere, the findings suggest that health-care systems may need to consider prioritising the sub-population of AAS users who experience appearance concerns. Further investigation of the clinical syndrome of AAS dependence is required, including its relation to body image and eating disorders. © 2018 Australasian Professional Society on Alcohol and other Drugs.

HOW THE DENSITY ENVIRONMENT CHANGES THE INFLUENCE OF THE DARK MATTER–BARYON STREAMING VELOCITY ON COSMOLOGICAL STRUCTURE FORMATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahn, Kyungjin, E-mail: kjahn@chosun.ac.kr

We study the dynamical effect of the relative velocity between dark matter and baryonic fluids, which remained supersonic after the epoch of recombination. The impact of this supersonic motion on the formation of cosmological structures was first formulated by Tseliakhovich and Hirata, in terms of the linear theory of small-scale fluctuations coupled to large-scale, relative velocities in mean-density regions. In their formalism, they limited the large-scale density environment to be that of the global mean density. We improve on their formulation by allowing variation in the density environment as well as the relative velocities. This leads to a new typemore » of coupling between large-scale and small-scale modes. We find that the small-scale fluctuation grows in a biased way: faster in the overdense environment and slower in the underdense environment. We also find that the net effect on the global power spectrum of the density fluctuation is to boost its overall amplitude from the prediction by Tseliakhovich and Hirata. Correspondingly, the conditional mass function of cosmological halos and the halo bias parameter are both affected in a similar way. The discrepancy between our prediction and that of Tseliakhovich and Hirata is significant, and therefore, the related cosmology and high-redshift astrophysics should be revisited. The mathematical formalism of this study can be used for generating cosmological initial conditions of small-scale perturbations in generic, overdense (underdense) background patches.« less

The distribution of emission-line galaxies in selected areas of the sky

NASA Astrophysics Data System (ADS)

Moody, J. Ward

1988-11-01

The author discusses the spatial distribution of emission-line galaxies (ELGs) relative to normal galaxies in several areas of the sky. Current evidence supports the notion that ELGs trace a low-density population in all the surveyed areas with the possible exception of the CfA "Slice of the Universe" survey. Based on this and other survey data in the north galactic cap, it is suggested that the ELGs inside the Bootes void may actually define the edge of a totally empty volume within an underdense distribution of normal galaxies.

The distribution of emission-line galaxies in selected areas of the sky

NASA Technical Reports Server (NTRS)

Moody, J. Ward

1988-01-01

The spatial distribution of emission-line galaxies (ELGs) relative to normal galaxies in several areas of the sky is discussed. Current evidence supports the notion that ELGs trace a low-density population in all the surveyed areas with the possible exception of the CfA 'Slice of the Universe' survey. Based on this and other survey data in the north galactic cap, it is suggested that the ELGs inside the Bootes void may actually define the edge of a totally empty volume within an underdense distribution of normal galaxies.

Colloquium P.G.de Gennes

ScienceCinema

None

2018-05-18

Lecture from Professor Pierre Gilles from Gennes, who received the Nobel Prize for Physics in 1991, became a professor at the Collège de France in 1971, director of the Ecole de Physique et Chimie (School of Physics and Chemistry) in Paris, etc.

Individual variability in the core interthreshold zone as related to body physique, somatotype, and physical constitution.

PubMed

Kakitsuba, Naoshi; Mekjavic, Igor B; Katsuura, Tetsuo

2009-11-01

For evaluating the effect of body physique, somatotype, and physical constitution on individual variability in the core interthreshold zone (CIZ), data from 22 healthy young Japanese male subjects were examined. The experiment was carried out in a climatic chamber in which air temperature was maintained at 20-24 degrees C. The subjects' body physique and the maximum work load were measured. Somatotype was predicted from the Heath-Carter Somatotype method. In addition, factors reflecting physical constitution, for example, susceptibility to heat and cold, and quality of sleep were obtained by questionnaire. The subjects wore a water-perfused suit which was perfused with water at a temperature of 25 degrees C and at a rate of 600 cc/min, and exercised on an ergometer at 50% of their maximum work rate for 10-15 min until their sweating rate increased. They then remained continuously seated without exercise until shivering increased. Rectal temperature (T(re)) and skin temperatures at four sites were monitored by thermistors, and sweating rate was measured at the forehead with a sweat rate monitor. Oxygen uptake was monitored with a gas analyzer. The results showed individual variability in the CIZ. According to the reciprocal cross-inhibition (RCI) theory, thermoafferent information from peripheral and core sensors is activated by T(re), mean skin temperature (T(sk)), and their changes. Since T(sk) was relatively unchanged, the data were selected to eliminate the influence of the core cooling rate on the sensor-to-effector pathway before RCI, and the relationship between the CIZ and the various factors was then analyzed. The results revealed that susceptibility to heat showed a good correlation with the CIZ, indicating that individual awareness of heat may change the CIZ due to thermoregulatory behavior.

Eating attitudes, self-esteem and social physique anxiety among Iranian females who participate in fitness programs.

PubMed

Gargari, B P; Khadem-Haghighian, M; Taklifi, E; Hamed-Behzad, M; Shahraki, M

2010-03-01

Today, women's participation in sports has substantially increased. This growth has been accompanied by concerns about health risks, as eating disorders, and psychological features, as self-esteem (SE) and social physique anxiety (SPA). The purpose of this study was to determine disordered eating attitudes and their relation to SE, SPA, as well as body weight, and body mass index (BMI), in Iranian females who participate in fitness programs. Subjects were 250 females, aged 14-51 years, who participated in fitness programs. Eating attitude test-26 (EAT-26), Rosenberg's self esteem scale (RSES), and social physique anxiety scale (SPAS), were used. Body weight and height were measured, and then Body Mass Index (BMI) was calculated. According to BMI cut-offs, 36% of subjects were overweight or obese. 28.4% and 19.6% of subjects were disordered eating attitudes (EAT-26>or=20) and low self-esteem (RSES<15), respectively. Disordered eating attitude subjects had lower SE and higher SPA, body weight and BMI than normal subjects (P<0.05). The low SE group had higher SPAS than normal one (P<0.02). In bivariate analysis, EAT-26 score was correlated negatively with RSES (r=-0.13, P<0.04) and positively with body weight, BMI, and SPAS (r=0.40, 0.42, and 0.47, respectively, P<0.001). SPAS had positive correlation with body weight and BMI (r=0.22, 0.19, It can be concluded that disordered eating attitudes are prevalent among Iranian females who participate in fitness programs. In this group, high SPA, body weight and BMI, and low SE accompany disordered eating attitudes.

Fluid dynamics alter Caenorhabditis elegans body length via TGF-β/DBL-1 neuromuscular signaling

PubMed Central

Harada, Shunsuke; Hashizume, Toko; Nemoto, Kanako; Shao, Zhenhua; Higashitani, Nahoko; Etheridge, Timothy; Szewczyk, Nathaniel J; Fukui, Keiji; Higashibata, Akira; Higashitani, Atsushi

2016-01-01

Skeletal muscle wasting is a major obstacle for long-term space exploration. Similar to astronauts, the nematode Caenorhabditis elegans displays negative muscular and physical effects when in microgravity in space. It remains unclear what signaling molecules and behavior(s) cause these negative alterations. Here we studied key signaling molecules involved in alterations of C. elegans physique in response to fluid dynamics in ground-based experiments. Placing worms in space on a 1G accelerator increased a myosin heavy chain, myo-3, and a transforming growth factor-β (TGF-β), dbl-1, gene expression. These changes also occurred when the fluid dynamic parameters viscosity/drag resistance or depth of liquid culture were increased on the ground. In addition, body length increased in wild type and body wall cuticle collagen mutants, rol-6 and dpy-5, grown in liquid culture. In contrast, body length did not increase in TGF-β, dbl-1, or downstream signaling pathway, sma-4/Smad, mutants. Similarly, a D1-like dopamine receptor, DOP-4, and a mechanosensory channel, UNC-8, were required for increased dbl-1 expression and altered physique in liquid culture. As C. elegans contraction rates are much higher when swimming in liquid than when crawling on an agar surface, we also examined the relationship between body length enhancement and rate of contraction. Mutants with significantly reduced contraction rates were typically smaller. However, in dop-4, dbl-1, and sma-4 mutants, contraction rates still increased in liquid. These results suggest that neuromuscular signaling via TGF-β/DBL-1 acts to alter body physique in response to environmental conditions including fluid dynamics. PMID:28725724

Epidemiological investigation of physique situation for birth high-risk children aged 9-15 years in Chengdu, Southwest China.

PubMed

Xiong, F; Yang, F; Huo, T Z; Li, P; Mao, M

2014-01-01

As the intrauterine environment can effect children's growth and development, this study aimed to explore the relationship between birth high-risk and physique situation of 9 to 15-year-old children by cross-sectional investigation, and to provide clues for the monitoring, prevention, and treatment of growth deviation in children. This study recruited 7,194 students aged 9 to 15 years in primary and junior schools. Their parents were asked to complete the birth situation questionnaire. Measurements included height, weight, and body mass index (BMI). Birth high-risk infant was defined according to the gestational age and birth weight. Growth deviation was classified as underweight, short stature, overweight, and obesity. The prevalence of all kinds of growth deviations in preterm, full-term, and post-term birth groups were similar, the same as the physique situation at school age among both sexes. The incidence of small for gestational age (SGA) was 6.23%, when at school age, part of SGA had catch-up growth. However, the prevalence of underweight and short stature for SGA was highest in three groups. The weight and height at school age in SGA group was less than that in appropriate for gestational age (AGA) and large for gestational age (LGA) groups. The prevalence of overweight and obesity for LGA and macrosomia were highest in three groups. At school age, the weight in macrosomia and LGA groups was higher than that in the other groups. Longitudinal height and weight development and growth of children with birth high-risk are different from normal children. In order to improve healthy situation, more attention should be paid to height and weight development of those children with birth high-risk at school age, even in pre-school age. Prevention may already begin during pregnancy.

Effects of Age and Sex on the Development of Personal Space Schemata Towards Body Build

ERIC Educational Resources Information Center

Lerner, Richard M.; And Others

1975-01-01

This study assessed personal space schemata of children towards stimulus figures representing male and female body build stereotypes. Greater spatial distances were used towards the Endomorph than other physique types and significant sex differences were found. (GO)

CDPP supporting tools to Solar Orbiter and Parker Solar Probe data exploitation

NASA Astrophysics Data System (ADS)

Genot, V. N.; Cecconi, B.; Dufourg, N.; Gangloff, M.; André, N.; Bouchemit, M.; Jacquey, C.; Pitout, F.; Rouillard, A.; Nathanaël, J.; Lavraud, B.; Durand, J.; Tao, C.; Buchlin, E.; Witasse, O. G.

2017-12-01

In recent years the French Centre de Données de la Physique des Plasmas (CDPP) has extended its data analysis capability by designing a number of new tools. In the solar and heliospheric contexts, and in direct support to the forthcoming solar ESA and NASA missions in these fields, these tools comprise of the Propagation Tool which helps linking solar perturbations observed both in remote and in-situ data; this is achieved through direct connection to the companion solar database MEDOC and the CDPP AMDA database. More recently, in the frame of Europlanet 2020 RI, a 1D MHD solar wind propagation code (Tao et al., 2005) has been interfaced to provide real time solar wind monitors at cruising probes and planetary environments using ACE real time data as inputs (Heliopropa service). Finally, simulations, models and data may be combined and visualized in a 3D context with 3DView. This presentation will overview the various functionalities of these tools and provide examples, in particular a 'CME tracking' case recently published (Witasse et al., 2017). Europlanet 2020 RI has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 654208.

The obesity penalty in the labor market using longitudinal Canadian data.

PubMed

Chu, Filmer; Ohinmaa, Arto

2016-12-01

A Canadian study of weight discrimination also known as the obesity wage-penalty. This paper adds to the limited Canadian literature while also introducing a causal model, which can be applied to future Canadian studies. A general working-class sample group is utilized with personal income, which removes many biases introduced in other studies. The evidence suggests that a 1-unit increase in lagged BMI is associated with a 0.7% decrease in personal for obese Canadian females. Similar to other studies, the male results are inconsistent. The evidence brought forward in this study can provide an effective financial incentive for health promotion among Canadians for law and policy makers. Beyond health reasons, these results can also be applied as empirical evidence of gender discrimination based on body image perception. The evidence suggests that male physique is not a contributing factor in income, but larger female physique is associated with lower personal income. Copyright © 2016 Elsevier B.V. All rights reserved.

Variability in body size and shape of UK offshore workers: A cluster analysis approach.

PubMed

Stewart, Arthur; Ledingham, Robert; Williams, Hector

2017-01-01

Male UK offshore workers have enlarged dimensions compared with UK norms and knowledge of specific sizes and shapes typifying their physiques will assist a range of functions related to health and ergonomics. A representative sample of the UK offshore workforce (n = 588) underwent 3D photonic scanning, from which 19 extracted dimensional measures were used in k-means cluster analysis to characterise physique groups. Of the 11 resulting clusters four somatotype groups were expressed: one cluster was muscular and lean, four had greater muscularity than adiposity, three had equal adiposity and muscularity and three had greater adiposity than muscularity. Some clusters appeared constitutionally similar to others, differing only in absolute size. These cluster centroids represent an evidence-base for future designs in apparel and other applications where body size and proportions affect functional performance. They also constitute phenotypic evidence providing insight into the 'offshore culture' which may underpin the enlarged dimensions of offshore workers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Self-compassion: a potential resource for young women athletes.

PubMed

Mosewich, Amber D; Kowalski, Kent C; Sabiston, Catherine M; Sedgwick, Whitney A; Tracy, Jessica L

2011-02-01

Self-compassion has demonstrated many psychological benefits (Neff, 2009). In an effort to explore self-compassion as a potential resource for young women athletes, we explored relations among self-compassion, proneness to self-conscious emotions (i.e., shame, guilt-free shame, guilt, shame-free guilt, authentic pride, and hubristic pride), and potentially unhealthy self-evaluative thoughts and behaviors (i.e., social physique anxiety, obligatory exercise, objectified body consciousness, fear of failure, and fear of negative evaluation). Young women athletes (N = 151; Mage = 15.1 years) participated in this study. Self-compassion was negatively related to shame proneness, guilt-free shame proneness, social physique anxiety, objectified body consciousness, fear of failure, and fear of negative evaluation. In support of theoretical propositions, self-compassion explained variance beyond self-esteem on shame proneness, guilt-free shame proneness, shame-free guilt proneness, objectified body consciousness, fear of failure, and fear of negative evaluation. Results suggest that, in addition to self-esteem promotion, self-compassion development may be beneficial in cultivating positive sport experiences for young women.

Marked for life? A prospective study of tattoos on appearance anxiety and dissatisfaction, perceptions of uniqueness, and self-esteem.

PubMed

Swami, Viren

2011-06-01

Previous studies on psychosocial aspects of tattooing have not examined prospective changes in self- and body-related attitudes as a result of obtaining a tattoo. In the present study, 82 British residents obtaining their first tattoo completed measures of state appearance anxiety and dissatisfaction prior to, and immediately after, obtaining a tattoo. They also completed measures of trait body appreciation, distinctive appearance investment, self-ascribed uniqueness, social physique anxiety, and self-esteem before obtaining a tattoo and three weeks later. Results showed that both women and men had significantly lower appearance anxiety and dissatisfaction immediately after obtaining their tattoo, and significantly higher body appreciation, distinctive appearance investment, self-ascribed uniqueness, and self-esteem after three weeks. Women reported greater social physique anxiety after three weeks, whereas men reported lower anxiety. These results are discussed in relation to the positive impacts of obtaining body art and the mainstreaming of tattooing in Western societies. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nutrition for winter sports.

PubMed

Meyer, Nanna L; Manore, Melinda M; Helle, Christine

2011-01-01

Winter sports are played in cold conditions on ice or snow and often at moderate to high altitude. The most important nutritional challenges for winter sport athletes exposed to environmental extremes include increased energy expenditure, accelerated muscle and liver glycogen utilization, exacerbated fluid loss, and increased iron turnover. Winter sports, however, vary greatly regarding their nutritional requirements due to variable physiological and physique characteristics, energy and substrate demands, and environmental training and competition conditions. What most winter sport athletes have in common is a relatively lean physique and high-intensity training periods, thus they require greater energy and nutrient intakes, along with adequate food and fluid before, during, and after training. Event fuelling is most challenging for cross-country skiers competing in long events, ski jumpers aiming to reduce their body weight, and those winter sport athletes incurring repeated qualification rounds and heats. These athletes need to ensure carbohydrate availability throughout competition. Finally, winter sport athletes may benefit from dietary and sport supplements; however, attention should be paid to safety and efficacy if supplementation is considered.

Spectral analysis of the solar wind turbulence in the vicinity of Venus

NASA Astrophysics Data System (ADS)

Teodorescu, Eliza; Echim, Marius; Munteanu, Costel; Voitcu, Gabriel; Zhang, Tielong; Barabash, Stanislav; Budnik, Elena; Fedorov, Andrei

2014-05-01

In this study we analyze magnetic field data provided by Venus Express (VEX) between 2007 and 2008. During each of the probe's eccentric polar orbit around Venus, VEX performs plasma and magnetic field measurements in the environment around the planet both in Venus induced magnetosphere and in the solar wind at several tens of thousands of kilometers away from the magnetosphere. This latter data set has a unique scientific value as it provides observations of magnetic turbulence in the solar wind around 0.72 AU, in the vicinity of Venus. We discuss a semi-automated method to select solar wind magnetic field data at 1 Hz from Venus Express Magnetometer (MAG) data by using plasma data from the Analyser of Space Plasma and Energetic Atoms (ASPERA). The time intervals when VEX is in the solar wind are automatically determined for 2007 and 2008. We apply a Fourier transform on the selected data and calculate the power spectral densities (PSD) of the turbulent magnetic field through Welch's algorithm. We compute the PSD of the three components of the magnetic field for the time intervals when both MAG and ASPERA were operating in the solar wind, for each VEX orbit between 1st of January 2007 and 31st of December 2008. The data base includes a number of 374 individual spectra. We discuss the spectral properties of turbulence and illustrate similarities between fast and slow wind during the minimum phase of the solar cycle for each of VEX's orbit which satisfies the selection criteria for a period of two years. Research supported by the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 313038/STORM, and a grant of the Romanian Ministry of National Education, CNCS - UEFISCDI, project number PN-II-ID-PCE-2012-4-0418. Data analysis was done with the AMDA science analysis system provided by the Centre de Données de la Physique des Plasmas (IRAP, Université Paul Sabatier, Toulouse) supported by CNRS and CNES.

Calendar of Selected Aeronautical and Space Meetings (Calendrier des Manifestations Aeronautiques et Spatiales (Selection)).

DTIC Science & Technology

1983-07-01

Structures, Matiriaux et Micanique appliquie 51 08 - Physique de l’Atmosphire et Environnement terrestre 70 09 - Information, Documentation et...78712 US VDE Verband Deutscher Elektrotechniker: Zentralstelle Tagungen, Stresemannallee 21, D-6000 Frankfurt am Main 70 GE WEC World Energy Conference

Specular reflectivity and hot-electron generation in high-contrast relativistic laser-plasma interactions

NASA Astrophysics Data System (ADS)

Kemp, Gregory Elijah

Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the cost of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic laser-plasma interactions. Spatial, temporal and spectral properties of the incident and specular pulses, both near and far away from the interaction region where experimental measurements are obtained, are used to benchmark simulations designed to infer dominant hot-electron acceleration mechanisms and their corresponding energy/angular distributions. To handle this highly coupled interaction, I employed particle-in-cell modeling using a wide variety of algorithms (verified to be numerically stable and consistent with analytic expressions) and physical models (validated by experimental results) to reasonably model the interaction's sweeping range of plasma densities, temporal and spatial scales, electromagnetic wave propagation and its interaction with solid density matter. Due to the fluctuations in the experimental conditions and limited computational resources, only a limited number of full-scale simulations were performed under typical experimental conditions to infer the relevant physical phenomena in the interactions. I show the usefulness of the often overlooked specular reflectivity measurements in constraining both high and low-contrast simulations, as well as limitations of their experimental interpretations. Using these experimental measurements to reasonably constrain the simulation results, I discuss the sensitivity of relativistic electron generation in ultra-intense laser plasma interactions to initial target conditions and the dynamic evolution of the interaction region.

A Psychometric Evaluation of the Self-Presentational Efficacy Scale

ERIC Educational Resources Information Center

Lamarche, Larkin; Gammage, Kimberley L.; Sullivan, Philip J.; Gabriel, David A.

2013-01-01

This study examined the psychometric properties of the Self-Presentational Efficacy Scale (SPES) developed by Gammage, Hall, and Martin Ginis (2004). University students (196 men and 269 women) completed the SPES and measures of social physique anxiety, fear of negative evaluation, and physical activity. Participants also completed the SPES a…

Stalking the Feast Beast.

ERIC Educational Resources Information Center

Trimpey, Lois

This paper discusses the use of Rational Recovery (RR) as a counseling technique in treating people who feel fat, particularly women. Fatness is viewed as a philosophy, not a physical condition. Cultural influences defining and stressing ideal femininity come down hard on women whose physiques or appearances do not measure up. RR gives people…

Puberty and Physical Self-Perceptions of Competitive Female Figure Skaters: An Interdisciplinary Approach

ERIC Educational Resources Information Center

Monsma, Eva V.; Malina, Robert M.; Feltz, Deborah L.

2006-01-01

This study considered the interrelationships among biological maturation and its physical correlates, social physique anxiety, and appearance-related physical self-perceptions in 113 adolescent female figure skaters participating in solo (n = 73) or partner contexts (n = 40). Participants were interviewed about their menarcheal status, underwent a…

Solar Power

ScienceCinema

None

2017-12-09

Le Prof. Broda, Prof. de Biochimie, Physique et Radiochimie à l'Université de Vienne, ville où il est né et où il a étudié, fait une brillante carrière accadémique et nous parle de l'énergie solaire.

Teenage Nutrition and Physique.

ERIC Educational Resources Information Center

Huenemann, Ruth L.; And Others

Body size, composition, and conformation in a teen-age population, and associated factors were studied to obtain useful data for planning programs in public health nutrition. This book describes the purpose, methods, and findings of this four-year longitudinal and cross-sectional study conducted in Berkeley, California, during the years 1961 to…

Self-similar perturbations of a Friedmann universe

NASA Technical Reports Server (NTRS)

Carr, Bernard J.; Yahil, Amos

1990-01-01

The present analysis of spherically symmetric self-similar solutions to the Einstein equations gives attention to those solutions that are asymptotically k = 0 Friedmann at large z values, and possess finite but perturbed density at the origin. Such solutions represent nonlinear density fluctuations which grow at the same rate as the universe's particle horizon. The overdense solutions span only a narrow range of parameters, and resemble static isothermal gas spheres just within the sonic point; the underdense solutions may have arbitrarily low density at the origin while exhibiting a unique relationship between amplitude and scale. Their relevance to large-scale void formation is considered.

The multiscale nature of magnetic pattern on the solar surface

NASA Astrophysics Data System (ADS)

Scardigli, S.; Del Moro, D.; Berrilli, F.

Multiscale magnetic underdense regions (voids) appear in high resolution magnetograms of quiet solar surface. These regions may be considered a signature of the underlying convective structure. The study of the associated pattern paves the way for the study of turbulent convective scales from granular to global. In order to address the question of magnetic pattern driven by turbulent convection we used a novel automatic void detection method to calculate void distributions. The absence of preferred scales of organization in the calculated distributions supports the multiscale nature of flows on the solar surface and the absence of preferred convective scales.

Literacy Is More than Books and Pens

ERIC Educational Resources Information Center

Roseboro, Anna J. Small

2012-01-01

Like parents, educators should prepare their students to do without them. To achieve this they must understand two concepts they hear about in the world of education: multiple intelligences and media literacy. Research on ways people learn and demonstrate knowledge shows that both are as diverse as the physiques of the students. Some of them learn…

Eating Attitudes and Their Psychological Correlates among Turkish Adolescents

ERIC Educational Resources Information Center

Bas, Murat; Asci, F. Hulya; Karabudak, Efsun; Kiziltan, Gul

2004-01-01

This study examined the eating attitudes and psychological characteristics of Turkish late adolescents. Seven hundred eighty-three university students were administered the Eating Attitudes Test, Rosenberg Self-Esteem Scale, State-Trait Anxiety Inventory, and Social Physique Anxiety Scale. More than one in ten (9.2% of the males and 13.1% of the…

Using Computer-Generated Random Numbers to Calculate the Lifetime of a Comet.

ERIC Educational Resources Information Center

Danesh, Iraj

1991-01-01

An educational technique to calculate the lifetime of a comet using software-generated random numbers is introduced to undergraduate physiques and astronomy students. Discussed are the generation and eligibility of the required random numbers, background literature related to the problem, and the solution to the problem using random numbers.…

Contributions and Implications of the Medford, Oregon, Boys' Growth Study.

ERIC Educational Resources Information Center

Clarke, H. H.

The overall and long-range purposes of the Medford Boys' Growth Study are: (1) to construct physical and motor growth curves and growth acceleration curves of boys seven to 18 years old; (2) to relate these traits to physiological maturity, physique type, nutritional status, socio-personal adjustment, interests, and scholastic aptitude and…

Free Space Optics Communication for Mobile Military Platforms

DTIC Science & Technology

2003-12-01

Federal Communications Commission FDA Food and Drug Administration FOV Field-of-View FSO Free Space Optics FWHM Full Width at Half Maximum Gbps...Physique et de Métrologie des Oscillateurs (LPMO) du CNRS UPR3203, associé à l’Université de Franche -Comté, 15 March 2002 [Schenk 2000] H. Schenk

L'education physique en Suisse Histoire et situation actuelle.

ERIC Educational Resources Information Center

Burgener, Louis

The document presents major aspects of the historical development and current situation of physical education in Switzerland. The study is designed as a manual for education students; as a reference book for educators, youth federations, sports associations, and the press; and as a volume to acquaint foreign readers with particular aspects of the…

The new role of scientists

ScienceCinema

None

2017-12-09

Le D.G. Jentschke fait l'introduction et présente le Prof.Kowarsky, spécialiste en microbiologie, physique nucléaire et une des fondateurs du Cern. Il parle entre autre de l'énergie nucléaire (pacifique)et de remise en questions des valeurs scientifiques et techniques

Calendar of Selected Aeronautical and Space Meetings (Calendrier des Manifestations Aeronautiques et Spatiales (Selection))

DTIC Science & Technology

1989-01-01

Structurces, Matdriaux et MWcanique appliqu&c 53 08 - Physique de U’Atmosph~re et Environnement terrestre 73 09 -Information, Documentation et Informatique 77...CO 80840 US UTIIS University of Tokyo Institute of Industrial Science: 7-22-1 Roppongi, Minato-ku, Tokyo 106 JA VDE Verband Deutscher

Calendar of Selected Aeronautical and Space Meetings, July 1989 (Calendrier des Manifestations Aeronautiques et Spatiales (Selection), Juillet 1989)

DTIC Science & Technology

1989-07-01

Matdriaux et Mcanique appliqude 56 08 - Physique de l’Atmosph6re et Environnement terrestre 76 09 - Information, Documentation et Informatique 82 10...S 917, 12201 Sunrise Valley Drive, Reston, VA 22092 US VDE Verband Deutscher Elektrotechniker: Zentralstelle Tagungen, Stresemannallee 15, D-6000

Calendar of Selected Aeronautical and Space Meetings (Calendrier des Manifestations Aeronautiques et Spatiales (Selection). Juillet-July 1984.

DTIC Science & Technology

1984-06-01

Structures, Mat~riaux et M~canique appliquce 47 08 - Physique de l’Atmnosph~re et Environnement terrestre 62 09 - Information, Documentation et...University Institute of Technology: Box 534,75121 Uppsala SW UW University of Wisconsin: Madison, WI 53706 US VDE Verbend Deutacher Elektroteclker

Nitramine Propellant Ignition and Combustion Research: New Tools and New Directions

DTIC Science & Technology

1989-02-01

promising innovation for the application of laser diagnostics to combustion studies is the use of planar imaging techniques. 13 This allows the...A.M. and Trott , W.M., J. de Physique 48, Colloq. C4, 179-188 (1987) 96. Fontijin, A., Ed. "Gas-Phase Chemiluminescence and Chemi-lonization," North

Stress habituation and alterations in perceived stress predict BMI percentile changes across a school year

USDA-ARS?s Scientific Manuscript database

Adolescents experience stressful situations at a high rate during school. Indeed, school is the most common source of stress for teens. This high rate of stress may promote increases in adiposity during a developmental period important for establishing the adult physique. Adiposity gains may be th...

Illustrating the body: Cross-sectional and prospective investigations of the impact of life drawing sessions on body image.

PubMed

Swami, Viren

2016-01-30

Life drawing sessions, where individuals produce drawings of the human figure from observations of a live model, may contain embodying elements that promote healthier body image. Two pilot studies were conducted to test this hypothesis. In Study 1, 138 individuals recruited from life drawing sessions in London, UK, estimated how many sessions they had attended in their lifetime and completed measures of negative and positive body image. In women, greater attendance was significantly associated with higher body appreciation and lower drive for thinness and social physique anxiety. In men, greater attendance was significantly associated with higher body appreciation, but not drive for muscularity or social physique anxiety. In Study 2, 37 women took part in a life drawing session for the first time. Compared to pre-session scores, participants had significantly more positive state body image and appearance satisfaction after the session. The findings of these studies suggest that life drawing may promote healthier body image, particularly among women, but further research is needed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Search for the Higgs Boson and for Anomalous Quartic Gauge Boson Couplings in the WW Channel with Dielectron Events with the D0 Experiment at the Tevatron; Recherche du boson de Higgs et de couplages de jauge quartiques anormaux dans le canal WW en électrons dans l'expérience D0 au Tevatron (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapon, Emilien

Le paysage de la physique des particules a subi des changements majeurs entre le début de cette thèse, en septembre 2010, et sa n en juin 2013. On peut notamment qualier l'année 2012 de date-clé dans l'histoire de la physique des particules. En 2012, une nouvelle particule a été découverte au LHC [1, 2], dont la majeure partie de la communauté s'accorde aujourd'hui à dire qu'il s'agit très probablement du boson de Higgs. Cet événement est intervenu peu après une sorte de passage de relais entre le Tevatron, arrêté le 30 septembre 2011, et le LHC, dont les toutes premièresmore » collisions sont intervenues le 23 novembre 2009.« less

ONLY THE LONELY: H I IMAGING OF VOID GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kreckel, K.; Van Gorkom, J. H.; Platen, E.

2011-01-15

Void galaxies, residing within the deepest underdensities of the Cosmic Web, present an ideal population for the study of galaxy formation and evolution in an environment undisturbed by the complex processes modifying galaxies in clusters and groups, as well as provide an observational test for theories of cosmological structure formation. We have completed a pilot survey for the H I imaging aspects of a new Void Galaxy Survey (VGS), imaging 15 void galaxies in H I in local (d < 100 Mpc) voids. H I masses range from 3.5 x 10{sup 8} to 3.8 x 10{sup 9} M{sub sun}, withmore » one nondetection with an upper limit of 2.1 x 10{sup 8} M{sub sun}. Our galaxies were selected using a structural and geometric technique to produce a sample that is purely environmentally selected and uniformly represents the void galaxy population. In addition, we use a powerful new backend of the Westerbork Synthesis Radio Telescope that allows us to probe a large volume around each targeted galaxy, simultaneously providing an environmentally constrained sample of fore- and background control samples of galaxies while still resolving individual galaxy kinematics and detecting faint companions in H I. This small sample makes up a surprisingly interesting collection of perturbed and interacting galaxies, all with small stellar disks. Four galaxies have significantly perturbed H I disks, five have previously unidentified companions at distances ranging from 50 to 200 kpc, two are in interacting systems, and one was found to have a polar H I disk. Our initial findings suggest void galaxies are a gas-rich, dynamic population which present evidence of ongoing gas accretion, major and minor interactions, and filamentary alignment despite the surrounding underdense environment.« less

Vibrations et relaxations dans les molécules biologiques. Apports de la diffusion incohérente inélastique de neutrons

NASA Astrophysics Data System (ADS)

Zanotti, J.-M.

2005-11-01

Le présent document ne se veut pas un article de revue mais plutôt un élément d'initiation à une technique encore marginale en Biologie. Le lecteur est supposé être un non spécialiste de la diffusion de neutrons poursuivant une thématique à connotation biologique ou biophysique mettant en jeu des phénomènes dynamiques. En raison de la forte section de diffusion incohérente de l'atome d'hydrogène et de l'abondance de cet élément dans les protéines, la diffusion incohérente inélastique de neutrons est une technique irremplaçable pour sonder la dynamique interne des macromolécules biologiques. Après un rappel succinct des éléments théoriques de base, nous décrivons le fonctionnement de différents types de spectromètres inélastiques par temps de vol sur source continue ou pulsée et discutons leurs mérites respectifs. Les deux alternatives utilisées pour décrire la dynamique des protéines sont abordées: (i)l'une en termes de physique statistique, issue de la physique des verres, (ii) la seconde est une interprétation mécanistique. Nous montrons dans ce cas, comment mettre à profit les complémentarités de domaines en vecteur de diffusion et de résolution en énergie de différents spectromètres inélastiques de neutrons (temps de vol, backscattering et spin-écho) pour accéder, à l'aide d'un modèle physique simple, à la dynamique des protéines sur une échelle de temps allant d'une fraction de picoseconde à quelques nanosecondes.

Fluctuations quantiques et instabilites structurales dans les conducteurs a basse dimensionalite

NASA Astrophysics Data System (ADS)

Dikande, Alain Moise

Un engouement particulier s'est manifeste ces dernieres annees pour les systemes electroniques fortement correles, ce en rapport avec l'immense richesse de leurs proprietes physiques. En general, ces proprietes sont induites par la presence d'interactions entre electrons qui, combinees a la structure du reseau moleculaire, donnent parfois lieu a une tres grande variete de phases electroniques et structurales ayant des incidences directes sur les phenomenes de transport dans ces materiaux. Les systemes electroniques couples a un reseau moleculaire et designes systemes electron-phonon font partie de cette classe de materiaux qui ont recemment capte l'attention, en raison notamment de la competition entre plusieurs echelles d'energie dans un environnement caracterise par une forte anisotropie cristalline et une dynamique moleculaire assez importante. En effet, en plus des proprietes electroniques et structurales particulieres la dimensionalite de ces systemes contribue egalement a leur richesse. Ainsi, une tres forte anisotropie structurale peut rehausser de facon considerable l'importance des interactions entre electrons et entre molecules constituant le reseau au point ou la physique du systeme soit regie par de tres fortes fluctuations. Ce dernier contexte est devenu un domaine a part de la physique des systemes fortement correles, a savoir celui des les phenomenes critiques quantiques . Parmi les systemes electron-phonon, on retrouve les composes inorganique KCP et organique TTF-TCNQ decouverts durant les annees 70, et explores en profondeur a cause de leur tendance vers une instabilite du type onde de densite de charge a basse temperature. Ces composes, en general designes systemes de Peierls en reference a l'instabilite de leurs structures electroniques regie par le reseau moleculaire, ont recemment connu un regain d'interet a la lumiere des nouveaux developpements dans les techniques de caracterisation des structures electroniques ainsi que sur le plan de concepts tel le Liquide de Luttinger, propres aux systemes electroniques a une dimension. (Abstract shortened by UMI.)

All-Manganite Tunnel Junctions with Interface-Induced Barrier Magnetism

NASA Astrophysics Data System (ADS)

Sefrioui, Zouhair

2011-03-01

The recent discovery of several unexpected phases at complex oxide interfaces is providing new insights into the physics of strongly correlated electron systems. The possibility of tailoring the electronic structure of such interfaces has triggered a great technological drive to functionalize them into devices. In this communication, we describe an alternative strategy to produce spin filtering by inducing a ferromagnetic insulating state in an ultrathin antiferromagnetic layer in contact with a ferromagnetic layer. This artificially induced spin filtering persists up to relatively high temperatures and operates at high applied bias voltages. The results suggest that after playing a key role in exchange-bias for spin-valves, uncompensated moments at engineered antiferromagnetic interfaces represent a novel route for generating highly spin-polarized currents with antiferromagnets. Work done in collaboration with M. Bibes, C. Carrétéro, A. Barthélémy (Unité Mixte de Physique CNRS/Thales, Campus de Polytechnique, 1, Avenue A. Fresnel, 91767 Palaiseau (France) and Université Paris-Sud, 91045 Orsay (France)), F.A. Cuellar, C. Visani, A. Rivera-Calzada, , C. León, J. Santamaria (Grupo de Física de Materiales Complejos, Universidad Complutense de Madrid, 28040 Madrid (Spain)), M.J. Calderón, L. Brey (Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid (Spain)), K. March, M. Walls, D. Imhoff (Laboratoire de Physique des Solides, CNRS, Université Paris-Sud, 91405 Orsay (France)), R. Lopez Anton, T.R. Charlton (ISIS, Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom)), E. Iborra (Universidad Politécnica de Madrid, Escuela Técnica Superior de Ingenieros de Telecomunicaciones, 28040 Madrid (Spain)), F. Ott (Léon Brillouin, CEA/CNRS, UMR 12, 91191 Gif-sur-Yvette (France)). This work was supported by the Spanish Ministry for Science and Education programs MAT2008 06517, and the Réseau Thématique de Recherche Avancée (RTRA) ``Triangle de la Physique.''

Effects of High vs. Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes Engaging in an 8-Week Resistance Training Program.

PubMed

Campbell, Bill I; Aguilar, Danielle; Conlin, Laurin; Vargas, Andres; Schoenfeld, Brad Jon; Corson, Amey; Gai, Chris; Best, Shiva; Galvan, Elfego; Couvillion, Kaylee

2018-02-06

Aspiring female physique athletes are often encouraged to ingest relatively high levels of dietary protein in conjunction with their resistance-training programs. However, there is little to no research investigating higher vs. lower protein intakes in this population. This study examined the influence of a high vs. low protein diet in conjunction with an 8-week resistance training program in this population. Seventeen females (21.2±2.1 years; 165.1±5.1 cm; 61±6.1 kg) were randomly assigned to a high protein diet (HP: 2.5g/kg/day; n=8) or a low protein diet (LP: 0.9g/kg/day, n=9) and were assessed for body composition and maximal strength prior to and after the 8-week protein intake and exercise intervention. Fat-free mass (FFM) increased significantly more in the HP group as compared to the LP group (p=0.009), going from 47.1 ± 4.5kg to 49.2 ± 5.4kg (+2.1kg) and from 48.1 ± 2.7kg to 48.7 ± 2 (+0.6kg) in the HP and LP groups, respectively. Fat mass significantly decreased over time in the HP group (14.1 ± 3.6kg to 13.0 ± 3.3kg; p<0.01) but no change was observed in the LP group (13.2 ± 3.7kg to 12.5 ± 3.0kg). While maximal strength significantly increased in both groups, there were no differences in strength improvements between the two groups. In aspiring female physique athletes, a higher protein diet is superior to a lower protein diet in terms of increasing FFM in conjunction with a resistance training program.

PATCHY BLAZAR HEATING: DIVERSIFYING THE THERMAL HISTORY OF THE INTERGALACTIC MEDIUM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamberts, Astrid; Chang, Philip; Pfrommer, Christoph

TeV-blazars potentially heat the intergalactic medium (IGM) as their gamma rays interact with photons of the extragalactic background light to produce electron–positron pairs, which lose their kinetic energy to the surrounding medium through plasma instabilities. This results in a heating mechanism that is only weakly sensitive to the local density, and therefore approximately spatially uniform, naturally producing an inverted temperature–density relation in underdense regions. In this paper we go beyond the approximation of uniform heating and quantify the heating rate fluctuations due to the clustered distribution of blazars and how this impacts the thermal history of the IGM. We analyticallymore » compute a filtering function that relates the heating rate fluctuations to the underlying dark matter density field. We implement it in the cosmological code GADGET-3 and perform large-scale simulations to determine the impact of inhomogeneous heating. We show that because of blazar clustering, blazar heating is inhomogeneous for z ≳ 2. At high redshift, the temperature–density relation shows an important scatter and presents a low temperature envelope of unheated regions, in particular at low densities and within voids. However, the median temperature of the IGM is close to that in the uniform case, albeit slightly lower at low redshift. We find that blazar heating is more complex than initially assumed and that the temperature–density relation is not unique. Our analytic model for the heating rate fluctuations couples well with large-scale simulations and provides a cost-effective alternative to subgrid models.« less

Foreword

NASA Astrophysics Data System (ADS)

Derrida, Bernard; Gaspard, Pierre; Van den Broeck, Christian

2007-06-01

We introduce and present the proceedings of the conference "Work, dissipation, and fluctuations in nonequilibrium physics" held in Brussels, 22-25 March 2006 under the auspices of the International Solvay Institutes for Physics and Chemistry and organized by the Center for Nonlinear Phenomena and Complex Systems of the Université Libre de Bruxelles. To cite this article: B. Derrida et al., C. R. Physique 8 (2007).

Psychological Well-Being and Motivation in a Turkish Physical Education Context

ERIC Educational Resources Information Center

Erturan-Ilker, Gökçe

2014-01-01

Using Self Determination as a framework, the purpose of the study was to examine the relationships between basic psychological needs, motivational regulations, self-esteem, subjective vitality, and social physique anxiety in physical education. One thousand and eighty two high school students aged between 14 and 19 [mean (M) = 15.89 ± 0.95 years]…

The Education and Training of Physics Teachers Worldwide. A Survey.

ERIC Educational Resources Information Center

Davies, Brian, Ed.

The Group Internationale de Recherche sur l'Enseignment de la Physique (GIREP), known in English as The International Research Group on Physics Teaching, is an independent association for the improvement of physics teaching in schools and, to a lesser extent, at the interface between school and university. Provided in this three-part book is…

Body Image Concerns in College-Aged Male Physical Education Students: A Descriptive Inquiry

ERIC Educational Resources Information Center

Olson, Michele S.; Esco, Michael R.; Willifo, Hank

2009-01-01

The purpose of this study was to examine body image concerns in college-aged male physical education majors. Sixty volunteers completed validated body image instruments including two-dimensional figure drawings. In general, the sample reported that they preferred a larger, more muscular physique reflective of male images that currently abound the…

Constitutive Behavior and Modeling of Al-Cu Alloy Systems

DTIC Science & Technology

2013-05-01

Mechanical Threshold of Dynamically Deformed Copper and Nitronic 40 ." Journal de Physique, 1985: 25- 34. Gama, B. A., S. L. Lopatnikov, and J. W. G...38 3. MODIFIED ZERILLI-ARMSTRONG MODEL .................................... 40 3.1 Introduction... 40 3.2 Former Modifications to ZA Model by Zerilli and Armstrong .. 42 3.3 Modifications to ZA Model

An example of a chaotic micromixer: the cross-channel micromixer

NASA Astrophysics Data System (ADS)

Dodge, Arash; Jullien, Marie-Caroline; Lee, Yi-Kuen; Niu, X.; Okkels, Fridolin; Tabeling, Patrick

2004-06-01

In this article dedicated to micromixing, we concentrate here on a particular micromixer - the 'cross-channel micromixer'. This mixer exploits an oscillatory perturbation to induce chaotic trajectories, favoring mixing. We present here theory, numerical simulations and experiments performed on this system. To cite this article: A. Dodge et al., C. R. Physique 5 (2004).

Health and Physique of School Children. Bulletin, 1925, No. 21

ERIC Educational Resources Information Center

Rogers, James Frederick

1925-01-01

This bulletin reports on the changes and progress in practice and conditions in: (1) School Housing; (2) Playgrounds; (3) Medical inspection; (4) Dental work; (5) Nutrition; (6) Open-air schools and open-window rooms; (7) The summer camp; (8) Other special schools and classes; (9) Health education; (10) Physical training; (11) Safety and first…

High Confinement and High Density with Stationary Plasma Energy and Strong Edge Radiation Cooling in Textor-94

NASA Astrophysics Data System (ADS)

Messiaen, A. M.

1996-11-01

A new discharge regime has been observed on the pumped limiter tokamak TEXTOR-94 in the presence of strong radiation cooling and for different scenarii of additional hearing. The radiated power fraction (up to 90%) is feedback controlled by the amount of Ne seeded in the edge. This regime meets many of the necessary conditions for a future fusion reactor. Energy confinement increases with increasing densities (reminiscent of the Z-mode obtained at ISX-B) and as good as ELM-free H-mode confinement (enhancement factor verus ITERH93-P up to 1.2) is obtained at high densities (up to 1.2 times the Greenwald limit) with peaked density profiles showing a peaking factor of about 2 and central density values around 10^14cm-3. In experiments where the energy content of the discharges is kept constant with an energy feedback loop acting on the amount of ICRH power, stable and stationary discharges are obtained for intervals of more than 5s, i.e. 100 times the energy confinement time or about equal to the skin resistive time, even with the cylindrical q_α as low as 2.8 β-values up to the β-limits of TEXTOR-94 are achieved (i.e. β n ≈ 2 of and β p ≈ 1.5) and the figure of merit for ignition margin f_Hqa in these discharges can be as high as 0.7. No detrimental effects of the seeded impurity on the reactivity of the plasma are observed. He removal in these discharges has also been investigated. [1] Laboratoire de Physique des Plasmas-Laboratorium voor Plasmafysica, Association "EURATOM-Belgian State", Ecole Royale Militaire-Koninklijke Militaire School, Brussels, Belgium [2] Institut für Plasmaphysik, Forschungszentrum Jülich, GmbH, Association "EURATOM-KFA", Jülich, Germany [3] Fusion Energy Research Program, Mechanical Engineering Division, University of California at San Diego, La Jolla, USA [4] FOM Institüt voor Plasmafysica Rijnhuizen, Associatie "FOM-EURATOM", Nieuwegein, The Netherlands [*] Researcher at NFSR, Belgium itemize

Effect of Eight-Week Exercise Program on Social Physique Anxiety Conditions in Adult Males

ERIC Educational Resources Information Center

Akyüz, Öznur

2017-01-01

Physiological changes occurring with physical activity have played role in appearance of a different field of study. Thus, examination of the effect of eight-week exercise program on SPA in adult males forms the purpose of the study. 20 sedentary males aged 18-25 voluntarily participated in the research. Volunteers were applied resistance exercise…

Psychometric Validation of the Brief Adaptation to Disability Scale-Revised for Persons with Spinal Cord Injury in Taiwan

ERIC Educational Resources Information Center

Lin, Chen-Ping; Wang, Chia-Chiang; Fujikawa, Mayu; Brooks, Jessica; Eastvold-Walton, Lissa; Maxwell, Kristin; Chan, Fong

2013-01-01

Purpose: To examine the measurement structure of the Brief Adaptation to Disability Scale-Revised (B-ADS-R). Measure: A 12-item measure of disability acceptance based on the four value changes (enlarging the scope of values, containing the effects of the disability, subordinating the physique, and transforming comparative-status values to asset…

Low Temperature Quartz Crystal Oscillator Fast Warm-Up Saw Oscillator.

DTIC Science & Technology

1981-07-01

TASK_Q Centre National de la Recherche ScientifiqueARA&WKLI k Laboratoire de Physique et Metrologie des!2 Oscillateurs - 50 Bsnon-F 2 3 32 av. o l...propri6t6s non lin6aires des ondes Alastiques de sur- face : applications aux oscillateurs et aux capteurs A quartz", Thse Besanqon, 1979. (6) D. Hauden, G

Partager : des technologies de pointe au service de la société

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2011-02-14

Médecine, climatologie, métrologie et informatique, les techniques utilisées par le LHC trouvent déjà des répercussions dans d’autres domaines scientifiques. Utilisant des techniques inédites, la physique des particules en fait bénéficier la société toute entière.

Body physique and proportionality of Brazilian female artistic gymnasts.

PubMed

Bacciotti, Sarita; Baxter-Jones, Adam; Gaya, Adroaldo; Maia, José

2018-04-01

This study aimed to identify physique characteristics (anthropometry, somatotype, body proportionality) of Brazilian female artistic gymnasts, and to compare them across competitive levels (sub-elite versus non-elite) within competitive age-categories. Two hundred forty-nine female gymnasts (68 sub-elite; 181 non-elite) from 26 Brazilian gymnastics clubs, aged 9-20 years and split into four age-categories, were sampled. Gymnasts were assessed for 16 anthropometric traits (height, weight, lengths, widths, girths, and skinfolds); somatotype was determined according to Heath-Carter method, body fat was estimated by bioimpedance, and proportionality was computed based on the z-phantom strategy. Non-elite and sub-elite gymnasts had similar values in anthropometric characteristics, however non-elite had higher fat folds in all age-categories (P < 0.01). In general, mesomorphy was the salient somatotype component in all age-categories, and an increase in endomorphy, followed by a decrease in ectomorphy across age was observed. Regarding proportionality, profile similarity was found between sub-elite and non-elite within age-categories. In conclusion results suggest the presence of a typical gymnast's physical prototype across age and competitive level, which can be useful to coaches during their selection processes in clubs and regional/national teams.

Sex differences in relative foot length and perceived attractiveness of female feet: relationships among anthropometry, physique, and preference ratings.

PubMed

Voracek, Martin; Fisher, Maryanne L; Rupp, Barbara; Lucas, Deanna; Fessler, Daniel M T

2007-06-01

Foot size proportionate to stature is smaller in women than in men, and small feet apparently contribute to perceived physical attractiveness of females. This exploratory study investigated the sex difference in relative foot length and interrelations among foot length, physique, and foot preference ratings in samples from Austria and Canada, each comprised of 75 men and 75 women. The findings included the following lines of evidence: the sex difference in relative foot length replicated in both data sets; the magnitude of this sex effect was large. Relative foot length was smaller in young, nulliparous, and slim women. Pointed-toe and high-heel shoes were more likely worn by smaller, lighter, and slimmer women. Men reported liking women's feet in general more than vice versa. A vast majority of both men and women favored small feet in women, but large feet in men. One's own foot size appeared to correspond to evaluations of attractiveness; particularly, women with small feet preferred small feet in women in general. The preference for small feet in women was convergent across different methods of evaluating attractiveness. Directions for investigations in this emerging field of research on physical attractiveness are discussed.

Etude vibroacoustique d'un systeme coque-plancher-cavite avec application a un fuselage simplifie

NASA Astrophysics Data System (ADS)

Missaoui, Jemai

L'objectif de ce travail est de developper des modeles semi-analytiques pour etudier le comportement structural, acoustique et vibro-acoustique d'un systeme coque-plancher-cavite. La connection entre la coque et le plancher est assuree en utilisant le concept de rigidite artificielle. Ce concept de modelisation flexible facilite le choix des fonctions de decomposition du mouvement de chaque sous-structure. Les resultats issus de cette etude vont permettre la comprehension des phenomenes physiques de base rencontres dans une structure d'avion. Une approche integro-modale est developpee pour calculer les caracteristiques modales acoustiques. Elle utilise une discretisation de la cavite irreguliere en sous-cavites acoustiques dont les bases de developpement sont connues a priori. Cette approche, a caractere physique, presente l'avantage d'etre efficace et precise. La validite de celle-ci a ete demontree en utilisant des resultats disponibles dans la litterature. Un modele vibro-acoustique est developpe dans un but d'analyser et de comprendre les effets structuraux et acoustiques du plancher dans la configuration. La validite des resultats, en termes de resonance et de fonction de transfert, est verifiee a l'aide des mesures experimentales realisees au laboratoire.

Exercise in middle-aged adults: self-efficacy and self-presentational outcomes.

PubMed

McAuley, E; Bane, S M; Mihalko, S L

1995-07-01

Whereas self-efficacy expectations have been identified as important determinants of exercise participation patterns, little empirical work that examines efficacy expectations as outcomes of exercise participation or their theoretical relationship to other psychological outcomes associated with exercise has been conducted. In the context of middle-aged males and females, the present study attempted to integrate social cognitive and impression management perspectives with respect to anxiety associated with exercise. Formerly sedentary subjects participated in a 5-month exercise program with assessments of physique anxiety, efficacy, outcome expectations, and anthropometric variables prior to and following the program. Both acute bouts and long-term participation in exercise resulted in significant increases in self-efficacy. In turn, these changes in efficacy and initial positive outcome expectations were significant predictors of reductions in physique anxiety, even when controlling for the influence of gender and reductions in body fat, weight, and circumferences. The findings are discussed in terms of the implications for structure and content of exercise environments and the utility of the proposed theoretical integration. Strategies for enhancing beliefs regarding health and fitness outcomes associated with exercise rather than appearance outcomes may be required to maximize reductions in negative body image.

List of Participants

NASA Astrophysics Data System (ADS)

2008-11-01

Mohab Abou ZeidInstitut des Hautes Études Scientifiques, Bures-sur-Yvette Ido AdamMax-Planck-Institut für Gravitationsphysik (AEI), Potsdam Henrik AdorfLeibniz Universität Hannover Mohammad Ali-AkbariIPM, Tehran Antonio Amariti Università di Milano-Bicocca Nicola Ambrosetti Université de Neuchâtel Martin Ammon Max-Planck-Institut für Physik, München Christopher AndreyÉcole Polytechnique Fédérale de Lausanne (EPFL) Laura AndrianopoliPolitecnico di Torino David AndriotLPTHE, Université UPMC Paris VI Carlo Angelantonj Università di Torino Pantelis ApostolopoulosUniversitat de les Illes Balears, Palma Gleb ArutyunovInstitute for Theoretical Physics, Utrecht University Davide AstolfiUniversità di Perugia Spyros AvramisUniversité de Neuchâtel Mirela BabalicChalmers University, Göteborg Foday BahDigicom Ioannis Bakas University of Patras Igor BandosUniversidad de Valencia Jose L F BarbonIFTE UAM/CSIC Madrid Till BargheerMax-Planck-Institut für Gravitationsphysik (AEI), Potsdam Marco Baumgartl Eidgenössische Technische Hochschule (ETH), Zürich James BedfordImperial College London Raphael BenichouLaboratoire de Physique Théorique, École Normale Supérieure, Paris Francesco Benini SISSA, Trieste Eric Bergshoeff Centre for Theoretical Physics, University of Groningen Alice BernamontiVrije Universiteit, Brussel Julia BernardLaboratoire de Physique Théorique, École Normale Supérieure, Paris Adel Bilal Laboratoire de Physique Théorique, École Normale Supérieure, Paris Marco Billo' Università di Torino Matthias Blau Université de Neuchâtel Guillaume BossardAlbert-Einstein-Institut, Golm Leonardo BriziÉcole Polytechnique Fédérale de Lausanne (EPFL) Johannes BroedelLeibniz Universität Hannover (AEI) Tom BrownQueen Mary, University of London Ilka BrunnerEidgenössische Technische Hochschule (ETH), Zürich Erling BrynjolfssonUniversity of Iceland Dmitri BykovSteklov Institute, Moscow and Trinity College, Dublin Joan CampsUniversitat de Barcelona Davide CassaniLaboratoire de Physique Théorique, École Normale Supérieure, Paris Alejandra CastroUniversity of Michigan Claudio Caviezel Max-Planck-Institut für Physik, München Alessio Celi Universitat de Barcelona Anna Ceresole Istituto Nazionale di Fisica Nucleare, Università di Torino Athanasios ChatzistavrakidisNational Technical University of Athens Wissam ChemissanyCentre for Theoretical Physics, University of Groningen Eugen-Mihaita CioroianuUniversity of Craiova Andres CollinucciTechnische Universität Wien Paul CookUniversità di Roma, Tor Vergata Lorenzo CornalbaUniversità di Milano-Bicocca Aldo CotroneKatholieke Universiteit Leuven Ben Craps Vrije Universiteit, Brussel Stefano Cremonesi SISSA, Trieste Riccardo D'AuriaPolitecnico di Torino Gianguido Dall'AgataUniversity of Padova Jose A de AzcarragaUniversidad de Valencia Jan de BoerInstituut voor Theoretische Fysica, Universiteit van Amsterdam Sophie de BuylInstitut des Hautes Études Scientifiques, Bures-sur-Yvette Marius de LeeuwUtrecht University Frederik De RooVrije Universiteit, Brussel Jan De Rydt Katholieke Universiteit Leuven and CERN, Geneva Bernard de WitInstitute for Theoretical Physics, Utrecht University Stephane DetournayIstituto Nazionale di Fisica Nucleare, Sezione di Milano Paolo Di Vecchia Niels Bohr Institute, København Eugen DiaconuUniversity of Craiova Vladimir Dobrev Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia Nick DoreyUniversity of Cambridge Hajar Ebrahim NajafabadiIPM, Tehran Federico Elmetti Università di Milano Oleg Evnin Vrije Universiteit, Brussel Francesco Fiamberti Università di Milano Davide Forcella SISSA, Trieste and CERN, Geneva Valentina Forini Humboldt-Universität zu Berlin Angelos Fotopoulos Università di Torino Denis Frank Université de Neuchâtel Marialuisa Frau Università di Torino Matthias Gaberdiel Eidgenössische Technische Hochschule (ETH), Zürich Diego Gallego SISSA/ISAS, Trieste Maria Pilar Garcia del MoralIstituto Nazionale di Fisica Nucleare, Università di Torino Valentina Giangreco Marotta PulettiUppsala University Valeria L GiliQueen Mary, University of London Luciano GirardelloUniversità di Milano-Bicocca Gian GiudiceCERN, Geneva Kevin Goldstein Institute for Theoretical Physics, Utrecht University Joaquim Gomis Universitat de Barcelona Pietro Antonio GrassiUniversità del Piemonte Orientale, Alessandria Viviane GraßLudwig-Maximilians-Universität, München Gianluca Grignani Università di Perugia Luca Griguolo Università di Parma Johannes GrosseJagiellonian University, Krakow Umut Gursoy École Polytechnique, Palaiseau Norberto Gutierrez RodriguezUniversity of Oviedo Babak HaghighatPhysikalisches Institut, Universität Bonn Troels Harmark Niels Bohr Institute, København Robert HaslhoferEidgenössische Technische Hochschule (ETH), Zürich Tae-Won HaPhysikalisches Institut, Universität Bonn Alexander HauptImperial College London and Max-Planck-Institut für Gravitationsphysik (AEI), Potsdam Marc HenneauxUniversité Libre de Bruxelles Johannes HennLAPTH, Annecy-le-Vieux Shinji HiranoNiels Bohr Institute, København Stefan HoheneggerEidgenössische Technische Hochschule (ETH), Zürich Jan HomannLudwig-Maximilians-Universität, München Gabriele Honecker CERN, Geneva Joost HoogeveenInstituut voor Theoretische Fysica, Universiteit van Amsterdam Mechthild HuebscherUniversidad Autónoma de Madrid Chris HullImperial College London Carmen-Liliana IonescuUniversity of Craiova Ella JasminUniversité Libre de Bruxelles Konstantin KanishchevInstitute of Theoretical Physics, University of Warsaw Stefanos Katmadas Utrecht University Alexandros KehagiasNational Technical University of Athens Christoph Keller Eidgenössische Technische Hochschule (ETH), Zürich Patrick Kerner Max-Planck-Institut für Physik, München Rebiai KhaledLaboratoire de Physique Mathématique et Physique Subatomique, Université Mentouri, Constantine Elias Kiritsis Centre de Physique Théorique, École Polytechnique, Palaiseau and University of Crete Denis KleversPhysikalisches Institut, Universität Bonn Paul Koerber Max-Planck-Institut für Physik, München Simon Koers Max-Planck-Institut für Physik, München Karl KollerLudwig-Maximilians-Universität, München Peter Koroteev Institute for Theoretical and Experimental Physics (ITEP), Moscow and Max-Planck-Institut für Gravitationsphysik (AEI), Potsdam Alexey KoshelevVrije Universiteit, Brussel Costas KounnasÉcole Normale Supérieure, Paris Daniel KreflCERN, Geneva Charlotte KristjansenNiels Bohr Institute, København Finn LarsenCERN, Geneva and University of Michigan Arnaud Le DiffonÉcole Normale Supérieure, Lyon Michael LennekCentre de Physique Théorique, École Polytechnique, Palaiseau Alberto Lerda Università del Piemonte Orientale, Alessandria Andreas LiberisUniversity of Patras Maria A Lledo Universidad de Valencia Oscar Loaiza-Brito CINVESTAV, Mexico Florian Loebbert Max-Planck-Institut für Gravitationsphysik (AEI), Potsdam Yolanda Lozano University of Oviedo Dieter Luest Ludwig-Maximilians-Universität, München Tomasz Łukowski Jagiellonian University, Krakow Diego Mansi University of Crete Alberto Mariotti Università di Milano-Bicocca Raffaele Marotta Istituto Nazionale di Fisica Nucleare, Napoli Alessio Marrani Istituto Nazionale di Fisica Nucleare and LNF, Firenze Andrea Mauri University of Crete Liuba Mazzanti École Polytechnique, Palaiseau Sean McReynoldsUniversità di Milano-Bicocca AKM Moinul Haque Meaze Chittagong University Patrick Meessen Instituto de Física Teórica, Universidad Autónoma de Madrid Carlo MeneghelliUniversità di Parma and Albert-Einstein-Institut, Golm Lotta Mether University of Helsinki and CERN, Geneva René Meyer Max-Planck-Institut für Physik, München Georgios MichalogiorgakisCenter de Physique Théorique, École Polytechnique, Palaiseau Giuseppe Milanesi Eidgenössische Technische Hochschule (ETH), Zürich Samuel Monnier Université de Genève Wolfgang MueckUniversità di Napoli Federico II Elena Méndez Escobar University of Edinburgh Iulian Negru University of Craiova Emil NissimovInstitute for Nuclear Research and Nuclear Energy, Sofia Teake NutmaCentre for Theoretical Physics, University of Groningen Niels Obers Niels Bohr Institute, København Olof Ohlsson SaxUppsala University Rodrigo OleaIstituto Nazionale di Fisica Nucleare, Sezione di Milano Domenico OrlandoUniversité de Neuchâtel Marta Orselli Niels Bohr Institute, København Tomas OrtinInstituto de Física Teórica, Universidad Autónoma de Madrid Yaron OzTel Aviv University Enrico PajerLudwig-Maximilians-Universität, München Angel Paredes GalanUtrecht University Sara PasquettiUniversité de Neuchâtel Silvia PenatiUniversità di Milano-Bicocca Jan PerzKatholieke Universiteit Leuven Igor PesandoUniversità di Torino Tassos PetkouUniversity of Crete Marios PetropoulosCenter de Physique Théorique, École Polytechnique, Palaiseau Franco PezzellaIstituto Nazionale di Fisica Nucleare, Sezione di Napoli Moises Picon PonceUniversity of Padova Marco PirroneUniversità di Milano-Bicocca Andrea PrinslooUniversity of Cape Town Joris RaeymaekersKatholieke Universiteit Leuven Alfonso RamalloUniversidade de Santiago de Compostela Carlo Alberto RattiUniversità di Milano-Bicocca Marco RauchPhysikalisches Institut, Universität Bonn Ronald Reid-EdwardsUniversity of Hamburg Patricia RitterUniversity of Edinburgh Peter RoenneDESY, Hamburg Jan RosseelUniversità di Torino Clement RuefService de Physique Théorique, CEA Saclay Felix RustMax-Planck-Institut für Physik, München Thomas RyttovNiels Bohr Institute, København and CERN, Geneva Agustin Sabio VeraCERN, Geneva Christian SaemannTrinity College, Dublin Houman Safaai SISSA, Trieste Henning SamtlebenÉcole Normale Supérieure, Lyon Alberto SantambrogioIstituto Nazionale di Fisica Nucleare, Sezione di Milano Silviu Constantin SararuUniversity of Craiova Ricardo SchiappaCERN, Geneva Ionut Romeo SchiopuChalmers University, Göteborg Cornelius Schmidt-ColinetEidgenössische Technische Hochschule (ETH), Zürich Johannes SchmudeSwansea University Waldemar SchulginLaboratoire de Physique Théorique, École Normale Supérieure, Paris Domenico SeminaraUniversità di Firenze Alexander SevrinVrije Universiteit, Brussel Konstadinos SfetsosUniversity of Patras Igor ShenderovichSt Petersburg State University Jonathan ShockUniversidade de Santiago de Compostela Massimo SianiUniversità di Milano-Bicocca Christoph SiegUniversità Degli Studi di Milano Joan SimonUniversity of Edinburgh Paul SmythUniversity of Hamburg Luca SommovigoUniversidad de Valencia Dmitri Sorokin Istituto Nazionale di Fisica Nucleare, Padova Christos SourdisUniversity of Patras Wieland StaessensVrije Universiteit, Brussel Ivan StefanovUniversity of Patras Sigurdur StefanssonUniversity of Iceland Kellogg Stelle Imperial College London Giovanni Tagliabue Università di Milano Laura Tamassia Katholieke Universiteit Leuven Javier TarrioUniversidade de Santiago de Compostela Dimitri TerrynVrije Universiteit, Brussel Larus Thorlacius University of Iceland Mario ToninDipartimento Di Fisica, Sezione Di Padova Mario Trigiante Politecnico di Torino Efstratios TsatisUniversity of Patras Arkady TseytlinImperial College London Pantelis TziveloglouCornell University, New York and CERN, Geneva Angel Uranga CERN, Geneva Dieter Van den Bleeken Katholieke Universiteit Leuven Ernst van Eijk Università di Napoli Federico II Antoine Van Proeyen Katholieke Universiteit Leuven Maaike van ZalkUtrecht University Pierre Vanhove Service de Physique Théorique, CEA Saclay Silvia Vaula Instituto de Física Teórica, Universidad Autónoma de Madrid Cristian Vergu Service de Physique Théorique, CEA Saclay Alessandro VichiÉcole Polytechnique Fédérale de Lausanne (EPFL) Marlene WeissCERN, Geneva and Eidgenössische Technische Hochschule (ETH), Zürich Sebastian Weiss Université de Neuchâtel Alexander WijnsUniversity of Iceland Linus WulffUniversity of Padova Thomas WyderKatholieke Universiteit Leuven Ahmed YoussefAstroParticule et Cosmologie (APC), Université Paris Diderot Daniela ZanonUniversità Degli Studi di Milano Andrea ZanziPhysikalisches Institut, Universität Bonn Andrey ZayakinInstitute for Theoretical and Experimental Physics (ITEP), Moscow Tobias ZinggUniversity of Iceland Dimitrios ZoakosUniversidade de Santiago de Compostela Emanuele ZorzanUniversità di Milano Konstantinos ZoubosNiels Bohr Institute, København

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valles, G.; Martin-Bragado, I.; Nordlund, K.

Recently, tungsten has been found to form a highly underdense nanostructured morphology (“W fuzz”) when bombarded by an intense flux of He ions, but only in the temperature window 900–2000 K. Furthermore, using object kinetic Monte Carlo simulations (pseudo-3D simulations) parameterized from first principles, we show that this temperature dependence can be understood based on He and point defect clustering, cluster growth, and detrapping reactions. At low temperatures (<900 K), fuzz does not grow because almost all He is trapped in very small He-vacancy clusters. At high temperatures (>2300 K), all He is detrapped from clusters, preventing the formation ofmore » the large clusters that lead to fuzz growth in the intermediate temperature range.« less

A photoionization instability in the early intergalactic medium

NASA Technical Reports Server (NTRS)

Hogan, Craig J.

1992-01-01

It is argued that any fairly uniform source of ionizing photons can be the cause of an instability in the pregalactic medium on scales larger than a photon path length. Underdense regions receive more ionizing energy per atom and reach higher temperature and entropy, driving the density down still further. Fluctuations created by this instability can lead to the formation of structures resembling protogalaxies and intergalactic clouds, obviating the need for gas clouds or density perturbations of earlier cosmological provenance, as is usually assumed in theories of galaxy and structure formation. Characteristic masses for clouds produced by the instability, with log mass in solar units plotted against log radius in kpc, are illustrated.

Polarization rotation in meteor burst communication systems

NASA Astrophysics Data System (ADS)

Cannon, P. S.

1986-06-01

Theoretical modeling of several meteor burst communication (MBC) paths indicates that polarization rotation losses are significant for a linearly polarized system operating near 40 MHz. Losses for a hybrid system with physical installation problems, consisting of linearly polarized transmitting and circularly polarized receiving antennas, were found to be less. Both ionospheric Faraday rotation polarization changes, and underdense meteor trail scattering wave polarization rotation, are considered. These losses are found to cause a 15-70 percent data throughput reduction of the value predicted for the situation without polarization rotation, in the two 40-MHz linearly polarized links considered for noon summer solstice conditions during high solar sunspot number periods. Qualitative experimental confirmation is provided through a cross polarization approach.

Evaluation de L’Effet du Vieillissement des Equipages sur les Consequences du Decalage Horaire (Evaluation of Crew Members Aging on Jet-Lag Consequences)

DTIC Science & Technology

2000-08-01

Ergonomia , 1987, 30, 13 79- physique que psychologique. Cela tend A damontrer que 1393. dans des conditions militaires op~rationnelles, les 2...melatonin. Ergonomia , 1987, 30, 1379- 1393. 2 - BLOIS R, FEINBERG I., GAILLARD J.M., KUPFER D.J. and WEBB W.B. Sleep in normal and pathological aging

Supersymmetric Higgs and radiative electroweak breaking

NASA Astrophysics Data System (ADS)

Ibáñez, Luis E.; Ross, Graham G.

2007-11-01

We review the mechanism of radiative electroweak symmetry breaking taking place in SUSY versions of the Standard Model. We further discuss different proposals for the origin of SUSY-breaking and the corresponding induced SUSY-breaking soft terms. Several proposals for the understanding of the little hierarchy problem are critically discussed. To cite this article: L.E. Ibáñez, G.G. Ross, C. R. Physique 8 (2007).

The Canadian Human Rights Act. Physical Handicap and Employment = Loi canadienne sur les droits de la personne. Le handicap physique et l'emploi.

ERIC Educational Resources Information Center

Canadian Human Rights Commission, Ottawa (Ontario).

This booklet presents administrative criteria for implementation of the Canadian Human Rights Act to be used by the Canadian Human Rights Commission to evaluate employment decisions affecting physically handicapped individuals. They are of value to employers who need to know how the Commission will analyze employer arguments that they have not…

Immersion francaise precoce: Education physique 1-7 (Early French Immersion: Physical Education for Grades 1-7).

ERIC Educational Resources Information Center

Burt, Andy; And Others

This curriculum guide for physical education is intended for use in grades 1-7 in the early French immersion program. It is a translation of the regular physical education program and a compilation of references and supplementary teaching material. It is noted that because of the comparative lack of references in French, much of the reference…

InSight Prelaunch Briefing

NASA Image and Video Library

2018-05-03

Philippe Lognonné, SEIS investigation lead, Institut de Physique du Globe de Paris (IPGP) discusses NASA's InSight mission during a prelaunch media briefing, Thursday, May 3, 2018, at Vandenberg Air Force Base in California. InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, is a Mars lander designed to study the "inner space" of Mars: its crust, mantle, and core. Photo Credit: (NASA/Bill Ingalls)

Physics 30: Grade 12 Diploma Examination = Physique 30: Examen en vue du diplome 12 annee.

ERIC Educational Resources Information Center

Alberta Dept. of Education, Edmonton. Student Evaluation Branch.

This document, in both English and French versions, is the Physics 30 Grade 12 Diploma Examination from Alberta Education. It is a 2.5 hour closed-book examination consisting of 37 multiple-choice and 12 numerical-response questions of equal value that are worth 70% of the examination, and 2 written-response questions of equal value worth 30% of…

The experimental violation of Bell's inequality [as predicted by quantum mechanics]: A contribution to the study of its meaning

NASA Astrophysics Data System (ADS)

Hespel, Bertrand

Au vu des expériences déjà réalisées, il est permis de penser que la violation de l'inégalité de Bell conformément aux prédictions de la mécanique quantique sera bientôt un fait établi. D'après les lectures qui en ont été le plus souvent données, en raison de la non- localité qu'il met en évidence et de l'incompatibilité qu'il y aurait entre cette propriété et celle de localité postulée par la relativité, ce fait annihilerait inéluctablement l'espoir qui animait le fondateur de la physique moderne et bon nombre de ses successeurs: à moins d'accepter d'abandonner l'exigence d'exactitude, nous devrions définitivement nous résoudre à admettre que nous ne pourrons jamais fournir du monde qu'une image incomplète. L'histoire de la philosophie suggère une toute autre interprétation. Lorsqu'on reconstitue les tentatives oubliées menées par Spinoza, Malebranche et Leibniz, pour bâtir, comme Newton, à la suite de Descartes, un Monde tout à la fois exact et complet, ce fait apparaît plutôt comme la preuve empirique que le monde est tout à la fois local et inséparable-phénoménalement local mais fondamentalement inséparable-et qu'une image adéquate ne pourra donc en être donnée qu'à la condition de reconnaître qu'il ne se réduit pas au contenu de l'espace-temps, c'est-à-dire que ce monde qui est l'objet de la physique n'est pas le tout du monde et qu'il convient de prolonger cette science, désormais quantique et relativiste, par une méta-physique.

Violences conjugales à Antananarivo (Madagascar): un enjeu de santé publique

PubMed Central

Gastineau, Bénédicte; Gathier, Lucy

2012-01-01

Introduction La violence conjugale a été étudiée dans beaucoup de pays développés mais peu en Afrique subsaharienne. Madagascar est un pays où ce phénomène est peu documenté. Méthodes En 2007, une enquête sur la violence conjugale à Antananarivo (ELVICA) a été menée sur la violence conjugale envers les femmes dans la capitale malgache. ELVICA a interrogé 400 femmes en union, de 15 à 59 ans. Des informations sur les caractéristiques démographiques, socioéconomiques des couples ont été collectées ainsi que sur les actes de violences physiques des hommes sur leurs épouses. L’objectif de cet article est d’identifier les facteurs de risques de la violence conjugale grave, celle qui a des conséquences sur la santé physique des femmes. Résultats Trente-cinq pour cent des femmes qui ont déclaré avoir subi au moins une forme de violence physique au cours des 12 mois précédent l’enquête. Presque la moitié (46%) des femmes violentées ont déclaré avoir déjà eu des hématomes, et environ un quart (23%) des plaies avec saignement. Vingt-deux pour cent ont déjà dû consulter un médecin. Parmi les nombreuses variables socioéconomiques et démographiques testées, quelques-unes sont associées positivement au risque de violence conjugale grave: le fait pour une femme d’être en union consensuelle et d’avoir une activité professionnelle. Il y aussi un lien entre la violence subie et l’autonomie des femmes (liberté accordée par le mari de travailler, de circuler, de voir sa famille). Conclusion A Madagascar, comme ailleurs, la lutte contre les violences conjugales est un élément majeur de l’amélioration du statut et de la santé des femmes. PMID:22514757

The Application of the SPASE Metadata Standard in the U.S. and Worldwide

NASA Astrophysics Data System (ADS)

Thieman, J. R.; King, T. A.; Roberts, D.

2012-12-01

The Space Physics Archive Search and Extract (SPASE) Metadata standard for Heliophysics and related data is now an established standard within the NASA-funded space and solar physics community and is spreading to the international groups within that community. Development of SPASE had involved a number of international partners and the current version of the SPASE Metadata Model (version 2.2.2) has not needed any structural modifications since January 2011 . The SPASE standard has been adopted by groups such as NASA's Heliophysics division, the Canadian Space Science Data Portal (CSSDP), Canada's AUTUMN network, Japan's Inter-university Upper atmosphere Global Observation NETwork (IUGONET), Centre de Données de la Physique des Plasmas (CDPP), and the near-Earth space data infrastructure for e-Science (ESPAS). In addition, portions of the SPASE dictionary have been modeled in semantic web ontologies for use with reasoners and semantic searches. While we anticipate additional modifications to the model in the future to accommodate simulation and model data, these changes will not affect the data descriptions already generated for instrument-related datasets. Examples of SPASE descriptions can be viewed at http://www.spase-group.org/registry/explorer and data can be located using SPASE concepts by searching the Virtual Space Physics Observatory (http://vspo.gsfc.nasa.gov/websearch/dispatcher) for data of interest.

The Application and Future Direction of the SPASE Metadata Standard in the U.S. and Worldwide

NASA Astrophysics Data System (ADS)

King, Todd; Thieman, James; Roberts, D. Aaron

2013-04-01

The Space Physics Archive Search and Extract (SPASE) Metadata standard for Heliophysics and related data is now an established standard within the NASA-funded space and solar physics community and is spreading to the international groups within that community. Development of SPASE had involved a number of international partners and the current version of the SPASE Metadata Model (version 2.2.2) has been stable since January 2011. The SPASE standard has been adopted by groups such as NASA's Heliophysics division, the Canadian Space Science Data Portal (CSSDP), Canada's AUTUMN network, Japan's Inter-university Upper atmosphere Global Observation NETwork (IUGONET), Centre de Données de la Physique des Plasmas (CDPP), and the near-Earth space data infrastructure for e-Science (ESPAS). In addition, portions of the SPASE dictionary have been modeled in semantic web ontologies for use with reasoners and semantic searches. In development are modifications to accommodate simulation and model data, as well as enhancements to describe data accessibility. These additions will add features to describe a broader range of data types. In keeping with a SPASE principle of back-compatibility, these changes will not affect the data descriptions already generated for instrument-related datasets. We also look at the long term commitment by NASA to support the SPASE effort and how SPASE metadata can enable value-added services.

Large-scale Environment of a z = 6.61 Luminous Quasar Probed by Lyα Emitters and Lyman Break Galaxies

NASA Astrophysics Data System (ADS)

Ota, Kazuaki; Venemans, Bram P.; Taniguchi, Yoshiaki; Kashikawa, Nobunari; Nakata, Fumiaki; Harikane, Yuichi; Bañados, Eduardo; Overzier, Roderik; Riechers, Dominik A.; Walter, Fabian; Toshikawa, Jun; Shibuya, Takatoshi; Jiang, Linhua

2018-04-01

Quasars (QSOs) hosting supermassive black holes are believed to reside in massive halos harboring galaxy overdensities. However, many observations revealed average or low galaxy densities around z ≳ 6 QSOs. This could be partly because they measured galaxy densities in only tens of arcmin2 around QSOs and might have overlooked potential larger-scale galaxy overdensities. Some previous studies also observed only Lyman break galaxies (LBGs; massive older galaxies) and missed low-mass young galaxies, like Lyα emitters (LAEs), around QSOs. Here we present observations of LAE and LBG candidates in ∼700 arcmin2 around a z = 6.61 luminous QSO using the Subaru Telescope Suprime-Cam with narrowband/broadband. We compare their sky distributions, number densities, and angular correlation functions with those of LAEs/LBGs detected in the same manner and comparable data quality in our control blank field. In the QSO field, LAEs and LBGs are clustering in 4–20 comoving Mpc angular scales, but LAEs show mostly underdensity over the field while LBGs are forming 30 × 60 comoving Mpc2 large-scale structure containing 3σ–7σ high-density clumps. The highest-density clump includes a bright (23.78 mag in the narrowband) extended (≳16 kpc) Lyα blob candidate, indicative of a dense environment. The QSO could be part of the structure but is not located exactly at any of the high-density peaks. Near the QSO, LAEs show underdensity while LBGs average to 4σ excess densities compared to the control field. If these environments reflect halo mass, the QSO may not be in the most massive halo but still in a moderately massive one. Based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

Statistical Measures of Large-Scale Structure

NASA Astrophysics Data System (ADS)

Vogeley, Michael; Geller, Margaret; Huchra, John; Park, Changbom; Gott, J. Richard

1993-12-01

\\inv Mpc} To quantify clustering in the large-scale distribution of galaxies and to test theories for the formation of structure in the universe, we apply statistical measures to the CfA Redshift Survey. This survey is complete to m_{B(0)}=15.5 over two contiguous regions which cover one-quarter of the sky and include ~ 11,000 galaxies. The salient features of these data are voids with diameter 30-50\\hmpc and coherent dense structures with a scale ~ 100\\hmpc. Comparison with N-body simulations rules out the ``standard" CDM model (Omega =1, b=1.5, sigma_8 =1) at the 99% confidence level because this model has insufficient power on scales lambda >30\\hmpc. An unbiased open universe CDM model (Omega h =0.2) and a biased CDM model with non-zero cosmological constant (Omega h =0.24, lambda_0 =0.6) match the observed power spectrum. The amplitude of the power spectrum depends on the luminosity of galaxies in the sample; bright (L>L(*) ) galaxies are more strongly clustered than faint galaxies. The paucity of bright galaxies in low-density regions may explain this dependence. To measure the topology of large-scale structure, we compute the genus of isodensity surfaces of the smoothed density field. On scales in the ``non-linear" regime, <= 10\\hmpc, the high- and low-density regions are multiply-connected over a broad range of density threshold, as in a filamentary net. On smoothing scales >10\\hmpc, the topology is consistent with statistics of a Gaussian random field. Simulations of CDM models fail to produce the observed coherence of structure on non-linear scales (>95% confidence level). The underdensity probability (the frequency of regions with density contrast delta rho //lineρ=-0.8) depends strongly on the luminosity of galaxies; underdense regions are significantly more common (>2sigma ) in bright (L>L(*) ) galaxy samples than in samples which include fainter galaxies.

Preferential Surface Adsorption in Miscible Blends of Polystyrene and Poly(vinyl methyl ether).

DTIC Science & Technology

1988-02-02

D. J. Phys. Chem. 1973, 74, 356. , c’’ 26~’::~ ~ ~ q,.,rf~.. w KRINMNIMVWU94M ~ ~ W-.TO"Kśtv X"- uV 23 25. Ober, R.; Paz, L.: Taupin , C.; Pincus, P...Boileau, S. Macromolecules 1983, 16 50. 26. DiMeglio, J.M.; Ober, R.; Paz, L.; Taupin , C.; Pincus, P.; Boileau, S. J. Physique 1983,4!, 1035. 27

Optimism and Cardiovascular Function in Children with Congenital Heart Disease

DTIC Science & Technology

2010-02-17

their theories. For example, Sigmund Freud (1856-1939) included references to both optimism and pessimism in his theory of human nature and...optimistic side of human nature and the drive towards death represents the pessimistic aspect of human nature ( Freud , 1927/1961, p. 8). The...W. (1977). Longitudinal physique changes among healthy white veterans at Boston. Human Biology, 49, 541-558. Freud , S. (1927/1961). Civilization

TREPS, a tool for coordinate and time transformations in space physics

NASA Astrophysics Data System (ADS)

Génot, V.; Renard, B.; Dufourg, N.; Bouchemit, M.; Lormant, N.; Beigbeder, L.; Popescu, D.; Toniutti, J.-P.; André, N.; Pitout, F.; Jacquey, C.; Cecconi, B.; Gangloff, M.

2018-01-01

We present TREPS (Transformation de REpères en Physique Spatiale) an online tool to perform coordinate transformations commonly used in planetology and heliophysics. It is based on SPICE kernels developed by NASA/NAIF. Its usage is straightforward, with a 4-step process, including various import/export options. Interoperability with external services is available through Virtual Observatory technology which is illustrated in a use case.

Picosecond Laser Pulse Interactions with Metallic and Semiconductor Surfaces.

DTIC Science & Technology

1983-11-01

Materials Research Society-Europe Meeting, Laset Solid Interactions and Transient Thermal Processing of Materials. Strasbourg, May 1983, 3. de Physique...of or assisting the heating of the sample. In this experiment the the Brillouin zone are involved, the index variations are de - probe fluence was...the entire range -of fluences below the threshold for phase transition. A de - tailed analysis of this fitting procedure is beyond the scope of 900

Medically Unexplained Physical Symptoms in Military Health (Symptomes physiques medicalement inexpliques dans la sante militaire)

DTIC Science & Technology

2017-12-01

Development of Persistent Pain and psychological Morbidity after Motor Vehicle Collision: Integrating the Potential Role of Stress Response Systems... abnormalities of quantitative EEG which suggest a THE LONG-TERM COSTS OF TRAUMATIC STRESS: INTERTWINED PHYSICAL AND PSYCHOLOGICAL CONSEQUENCES STO-TR-HFM...S.A., Clauw, D.J., Abelson, J.L. et al., The development of persistent pain and psychological morbidity after motor vehicle collision: integrating

Calendar of Selected Aeronautical and Space Meetings (Calendrier des Manifestations Aeronautiques et Spatiales (Selection)).

DTIC Science & Technology

1983-01-01

Physique de l’Atmosphire et Environnement terrestre 71 09 - Information, Documentation et Informatique 74 10 - Thimes gin~raux (pluridisciplinaires) et...March Louisiana (US) Fiber Communication Optical Communications IEEE Fibre Optics Electro-Optics 02-08 7-9 March Baden-Baden VDE -IEEE Specialists...Conference on Very Large Electronic Systems VDE (GE) Scale Integrated Circuits Solid State Devices IEEE Integrated Circuits Engineering Design Fabrication

Nonlinear Optical Interactions in Semiconductors.

DTIC Science & Technology

1985-12-10

Physique du Solide et Energie Solaire We had on-going interaction with Dr. Christian Verie on the growth of high quality narrow-gap semiconductor crystals...The band gap energy of the semiconductor decreases with increasing temperature. Consequently, the absorption of light in the energy region of the...gas and, more importantly, will modulate the electron energy at the difference frequency, wI - 02" Under ordinary circumstances such an energy (or

Nonlinear Optical Interactions in Semiconductors

DTIC Science & Technology

1984-10-01

TACAN Aerospace Corporation. 6 V. Coupling A. C.N.R.S., Physique du Solide et Energie Solaire We have an on-going interaction with Dr. Christian...optical fiber to the semiconductor sample and back to the analyzing electronics. The band-gap energy of the semiconductor decreases with increasing...temperature. Consequently, the absorption of light in the energy region of the band-gap changes with temperature. From the measured light absorption, the

Nonlinear Optical Interactions in Semiconductors

DTIC Science & Technology

1984-03-16

aU internal audits for TACAN Corporation. 7 V. Coupling A, C. N. R. S., Physique du Solide et Energie Solaire We have an ongoing interaction with Dr...fiber to the semiconductor sample and back to the analyzing electronics. The band gap energy of the semiconductor decreases with increasing tem- perature...Consequently, the absorption of light in the energy region of the band gap changes with temperature. From the measured light absorp- tion, the

The low birth-weight infants of Saudi adolescents: maternal implications.

PubMed

al-Sibai, M H; Khwaja, S S; al-Suleiman, S A; Magbool, G

1987-11-01

Maternal factors and perinatal outcome of low birth-weight (less than or equal to 2,500 g) infants of 46 adolescent mothers was studied and compared with 160 adolescents who delivered infants weighing greater than 2,500 g. The significant factors found in the low birth-weight group were anaemia, small maternal physique and preterm delivery. Expectedly, the perinatal mortality rate was significantly increased in low birth-weight infants.

Association between somatotypes and blood pressure in an adult Chuvasha population.

PubMed

Kalichman, Leonid; Livshits, Gregory; Kobyliansky, Eugene

2004-01-01

The relationship between blood pressure (BP) and anthropometrical characteristics has been indeed examined extensively, but only a few studies have investigated any connection of somatotypes to BP. to evaluate the association between BP and various anthropometrical characteristics, including components of somatotypes (using the methods of Heath and Carter and of Deriabin). The study sample comprised 783 males aged 18-89 years and 720 females aged 18-90 years, all residents of the Chuvasha, Russian Federation. We used multiple regression, Pearson's and canonical correlation analyses. Significant correlations (r = 0.19-0.28, p < 0.05) were obtained between BP and anthropometric characteristics associated with body compositions and somatotypes. The most impressive were the canonical correlations between BP and somatotype components derived according to Heath and Carter (0.275), and according to Deriabin's (0.333) method. Different body types were highly significantly (P < 0.001) associated with systolic and diastolic BP. Individuals of robust physique (with high endomorphy and mesomorphy) showed high mean values of systolic and diastolic BP, whereas the smallest persons had the lowest BP values. These findings suggest the existence of common physiological paths in the development of body physique and blood pressure regulation and may possibly be indicative of the involvement of pleiotropic genetic and/or epigenetic mechanisms in this regulation.

Somatotype in elderly type 2 diabetes patients.

PubMed

Buffa, Roberto; Floris, Giovanni; Putzu, Paolo F; Carboni, Luciano; Marini, Elisabetta

2007-09-01

Somatotyping is a practical technique for the description of physique. Individuals with Type 2 diabetes are characterized by physical peculiarities, such as overweight, obesity and a central pattern of body fat distribution. Somatotype applications to diabetes are limited. The objective of this study is to describe the somatotype of elderly type 2 diabetes patients. The sample consisted of 110 patients with type 2 diabetes (45 men, mean age 69.4 +/- 7.0 years; 65 women, mean age 72.9 +/- 7.1 years). The pathological subjects were compared with a control group consisting of 280 healthy individuals (134 men, mean age 74.2 +/- 7.3 years; 146 women, mean age 74.9 +/- 7.4 years). The Heath-Carter somatotype was applied. Diabetic men and women (mean somatotype, respectively: 6.8-5.6-0.6 and 8.6-6.4-0.2) presented significantly higher values of endomorphy than the controls (p = 0.043 in men, p = 0.003 in women); men also had a lower mesomorphic component (p = 0.000). The somatotype method revealed physical peculiarities in type 2 diabetes patients. The marked endomorphy in the pathological individuals can be related to general fatness, which is a well known disease risk factor. The somatotype appears to be a suitable technique for the assessment of physique in type 2 diabetes patients.

Self-identity and the theory of planned behaviour: between- and within-participants analyses.

PubMed

Hagger, Martin S; Chatzisarantis, Nikos L D

2006-12-01

Two studies addressed the hypothesis that a minority of people are more oriented towards their self-identity when forming intentions to act than the traditional antecedents of intentional action; attitudes, subjective norms and perceived behavioural control (PBC). In Study 1, participants (N=241) completed measures of an augmented version of theory of planned behaviour (TPB) that included self-identity for 30 behaviours. Using within-participants multiple regression analyses, the sample was classified into self-identity-oriented (SI-oriented) and TPB-oriented groups. Between-participants multiple regression analyses revealed that self-identity was a significantly stronger predictor of intentions and accounted for significantly more incremental variance in intentions in the SI-oriented sample compared with the TPB-oriented sample across the 30 behaviours. In Study 2, participants (N=250) completed the same TPB and self-identity measures used in Study 1 as well as measures of generalized self-concept and social physique anxiety for dieting behaviour. Results indicated that self-identity was significantly associated with the generalized self-related measures, and self-concept and social physique anxiety moderated the self-identity-intention relationship. This investigation provides some preliminary evidence to support the effect of individual differences in self-identity on the formation of intentions to act.

Dietary Intake, Body Composition, and Menstrual Cycle Changes during Competition Preparation and Recovery in a Drug-Free Figure Competitor: A Case Study

PubMed Central

Halliday, Tanya M.; Loenneke, Jeremy P.; Davy, Brenda M.

2016-01-01

Physique competitions are events in which competitors are judged on muscular appearance and symmetry. The purpose of this retrospective case study was to describe changes in dietary intake, body mass/composition, and the menstrual cycle during the 20-week competition preparation (PREP) and 20-week post competition recovery (REC) periods of a drug-free amateur female figure competitor (age = 26–27, BMI = 19.5 kg/m2). Dietary intake (via weighed food records) and body mass were assessed daily and averaged weekly. Body composition was estimated via Dual-energy X-ray absorptiometry (DXA) and 7-site skinfold measurements. Energy intake, body mass and composition, and energy availability decreased during the 20-week PREP period (changes of ~298 kcals, 5.1 kg, 6.5% body fat, and 5.4 kcal/kg fat free mass, respectively) and returned to baseline values by end of the 20-week REC period. Menstrual cycle irregularity was reported within the first month of PREP and the last menstruation was reported at week 11 of PREP. Given the potentially adverse health outcomes associated with caloric restriction, future, prospective cohort studies on the physiological response to PREP and REC are warranted in drug-free, female physique competitors. PMID:27879627

Theorie de la Levitation Radiative a L'equilibre dans les Etoiles Naines Blanches Chaudes

NASA Astrophysics Data System (ADS)

Chayer, Pierre

1995-01-01

Les resultats de nouveaux calculs detailles de levitation radiative dans des naines blanches chaudes utilisant la base de donnees atomiques TOPBASE sont presentes. Des accelerations radiatives et des abondances d'equilibre ont ete calculees pour C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, et Fe, sur des grilles de modeles d'enveloppes stellaires riches en hydrogene et riches en helium. La grille des modeles de DA a des gravites telles que log g = 7.0, 7.5, 8.0, et 8.5, et couvre les temperatures effectives pour lesquelles 100,000K >= T_ {rm eff} >= 20,000K par sauts de 2,500K. La grille des modeles de DO/DB est similaire mais se prolonge a T_{rm eff } = 130,000K. Les resultats d'abondances d'equilibre de Ni dans des DA utilisant la base de donnees de Kurucz sont aussi presentes. Nous discutons dans les moindres details de la physique incluse dans les calculs afin de fournir une bonne comprehension physique de la levitation radiative sous les conditions rencontrees dans les naines blanches. Nous discutons aussi de la forme et de la dependance en fonction de la profondeur des reservoirs des elements, crees par un equilibre entre l'acceleration radiative et la gravite locale effective dans differentes enveloppes stellaires. Nous soulignons le role important joue dans la morphologie de ces reserviors par les etats d'ionisation dominants se trouvant dans la configuration gaz noble. Nos resultats centraux sont presentes sous forme de figures montrant le comportement de l'abondance photospherique estimee pour chaque element en fonction de la temperature effective et de la gravite de surface. Nous apportons egalement des ameliorations aux calculs de levitation radiative en utilisant une approche de modeles d'atmospheres pour les etoiles riches en hydrogene. Nous mettons l'emphase, en particulier, sur le role des traces d'elements lourds qui peuvent etre presents dans le plasma. Nous utilisons une table d'opacite monochromatique detaillee calculee pour un plasma compose de H contenant de faibles quantites de C, N, O, et Fe pour illustrer comment les abondances d'equilibre des elements supportes reagissent a la redistribution du flux causee par l'addition de ces traces de matiere opaque. Nous traitons ce probleme, en premier lieu, selon une approche basee sur des modeles d'enveloppes et, en second lieu, selon une approche basee sur des modeles d'atmospheres. Nous considerons aussi deux autres ameliorations concernant, premierement, un traitement plus sophistique de la redistribution de la quantite de mouvement d'un ion suite a l'absorption d'un photon, et deuxiemement, l'utilisation d'une meilleure valeur de la largeur du profil de raie associee a l'elargissement par pression. Bien qu'une poignee d'abondances soient disponibles a partir de l'analyse des observations qui ont ete faites jusqu'a maintenant, nous sommes neanmoins capables de conclure, a l'aide de comparaisons detaillees, que la theorie de la levitation radiative a l'equilibre ne reussit pas a expliquer quantitativement les patrons d'abondances des elements lourds observes dans les naines blanches chaudes. Au moins un autre mecanisme doit competionner avec la levitation radiative et le triage gravitationnel dans les atmospheres/enveloppes des naines blanches chaudes. Nous suggerons la possibilite d'un vent stellaire ou encore la possibilite d'accretion.

The Neutral Islands during the Late Epoch of Reionization

NASA Astrophysics Data System (ADS)

Xu, Yidong; Yue, Bin; Chen, Xuelei

2018-05-01

The large-scale structure of the ionization field during the epoch of reionization (EoR) can be modeled by the excursion set theory. While the growth of ionized regions during the early stage are described by the ``bubble model'', the shrinking process of neutral regions after the percolation of the ionized region calls for an ``island model''. An excursion set based analytical model and a semi-numerical code (islandFAST) have been developed. The ionizing background and the bubbles inside the islands are also included in the treatment. With two kinds of absorbers of ionizing photons, i.e. the large-scale under-dense neutral islands and the small-scale over-dense clumps, the ionizing background are self-consistently evolved in the model.

Moving to Inclusion. Active Living through Physical Education: Maximizing Opportunities for Students with a Disability = Integration en Mouvement. La vie active par l'education physique: Multipliez les possibilities offertes aux eleves ayant un handicap.

ERIC Educational Resources Information Center

Active Living Alliance for Canadians with a Disability, Gloucester (Ontario).

This document is composed of 10 manuals which provide both general and specific guidelines to facilitate the inclusion of Canadian students with disabilities in physical education programs. An introductory manual identifies general concepts, strategies, and practical approaches that can be used in an inclusive physical education program. It…

Characteristics of a Steadily Operating Metal Combustor

DTIC Science & Technology

1976-08-01

Physique, Serie 7, Vol. 17, p. 510-576, 1899. 18. Zintl, E., Harder, A., and Dauth, B., "Gitterstruktur Der Oxyde , Sulfide, Selenide Und Telluride Des...ethyl alcohol were added to the cylinder along with three drops of alizarin Red S indicator (1%). The solution was titrated with thorium nitrate until...the appearance of a faint pink color. The thorium nitrate precipitated thorium fluoride which is insoluble in ethyl alcohol , and the indicator detected

MEASUREMENT OF THE RADIOACTIVE CONTAMINATION OF THE FOOD CHAIN (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chevallier, A.; Schneider, R.

ABS>The results obtained at the Laboratoire de Protection of 1'Institut de Physique Biologique, Strasbourg, from 1958 to 1960 on the contamination of food are tabulated. The methods used for the measurement of the total beta activity and for the radiochemical separations and determination of the elements isolated are described for milk and vegetables. The activities found in milk, vegetables, and animal skeletons are given in tabular form. (J.S.R.)

Free field theory as a string theory?

NASA Astrophysics Data System (ADS)

Gopakumar, Rajesh

2004-11-01

An approach to systematically implement open-closed string duality for free large N gauge theories is summarised. We show how the relevant closed string moduli space emerges from a reorganisation of the Feynman diagrams contributing to free field correlators. We also indicate why the resulting integrand on moduli space has the right features to be that of a string theory on AdS. To cite this article: R. Gopakumar, C. R. Physique 5 (2004).

Calendar of Selected Aeronautical and Space Meetings January 1991 Onwards (Calendrier des Manifestations Aeronautiques et Spatiales (Selection) Janvier 1991 et au-dela)

DTIC Science & Technology

1990-12-01

e 39 08 - Physique de l’Atmosph~re et Environnement terrestre 55 09 - Information, Documentation et Informatique 58 10 - Th~rnes g6n6raux...Fax (02) 692 2012 OS UV University of Vienna: Liebigasse 4/3-4, A- 1010 Wien Tel 43.1.43.67.12 Fax 43.1.43.01.97 AU VDE Verband Deutscher

Partager : des technologies de pointe au service de la société

ScienceCinema

None

2018-04-27

Médecine, climatologie, métrologie et informatique, les techniques utilisées par le LHC trouvent déjà des répercussions dans d’autres domaines scientifiques. Utilisant des techniques inédites, la physique des particules en fait bénéficier la société toute entière.

High-Lift System Aerodynamics (L’Aerodynamique des Systems Hypersustentateurs)

DTIC Science & Technology

1993-09-01

les kcouleinents incoinpressibles sur les profils L -a pr~sente m~thode num~rique montre que la simulation multi-corps, qui est un...de l ’&oulement du d𔄀chelle de discrdtisation, d’origine physique, introduit des m~me ordre que l ’~paisseur des couches limites sur le point de...hypersustentateurs. Enfin, les consequences des exigences de furtivite sur la forme des aeronefs - c’est it dire la creation de configurations telles que

Voyage dans le noir. Trous noirs, matière noire, énergie noire et antimatière [Journey in the dark. Black holes, dark matter, dark energy and antimatter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvarez-Gaume, Luis; Doser, Michael; Grojean, Chri

2009-11-26

Et si nous faisions avec les physiciens un voyage dans le noir ? De l'astrophysique à la physique des particules les trois noirs, la matière noire, l'énergie noire ou l’antimatière intriguent et fascinent. Que sont ces objets qui bousculent nos idées et qui véhiculent parfois des craintes irraisonnées? Luis Alvarez-Gaume, Michael Doser et Christophe Grojean, physiciens du CERN vous invitent à mettre en lumière (!) les constituants de base de la matière et à explorer les mystères de la physique contemporaine. Une soirée lumineuse pour éclairer des concepts et ne plus avoir peur du noir. [ What if we mademore » a trip to the physicists in the dark? From astrophysics to particle physics the three blacks, dark matter, dark energy or antimatter intrigue and fascinate. What are these objects that jostle our ideas and sometimes convey irrational fears? Luis Alvarez-Gaume, Michael Doser and Christophe Grojean, CERN physicists invite you to highlight (!) The basic constituents of matter and to explore the mysteries of contemporary physics. A bright evening to illuminate concepts and not be afraid of the dark.]« less

Social Physique Anxiety, Mental Health, and Exercise: Analyzing the Role of Basic Psychological Needs and Psychological Inflexibility.

PubMed

Alcaraz-Ibáñez, Manuel; Sicilia, Álvaro; Burgueño, Rafael

2017-02-22

This study aimed to determine the usefulness of integrating basic psychological needs theory (BPNT) and relational frames theory (RFT) in order to explain the effects of social physique anxiety (SPA) - in the context of exercise - on exercisers' mental health. A total of 296 recreational cyclists and triathletes (100% males) aged 18 to 60 years old (M age = 35.65, SD = 9.49) completed a multi-section questionnaire assessing the target variables. Two models of structural equations with multiple mediators were tested using 5000 bootstrap samples. While the BPNT-based model explained 20% of variance in satisfaction with life (SWL) and 25% of variance in mental health (MH), the model that also incorporated RFT explained 43% of variance in both of those variables. Results showed that SPA negatively impacted exercisers' mental health via two different mechanisms: a) through a decrease in perceived satisfaction of basic psychological needs (β = -.05, p = .045 for SWL; β = -.07, p = .002 for MH); b) through an increase in psychological inflexibility, generated directly by SPA (β = -.24, p < .001 for SWL; β = -.20, p < .001 for MH) and also mediated by basic psychological need thwarting (β = -.09, p < .001 for SWL; β = -.08, p = .002 for MH). Results supported integrating the two theories, elucidating the processes by which a controlling social factor like SPA can affect the potential benefits of exercise.

Clinical significance of low result of 1-h 50-g glucose-challenge test in pregnant women.

PubMed

Oawada, Nozomi; Aoki, Shigeru; Sakamaki, Kentaro; Obata, Soichiro; Seki, Kazuo; Hirahara, Fumiki

2018-01-31

The objective of this study is to examine the effect of low-glucose value on the 1-h 50-g glucose challenge test (GCT) on neonatal body weight in low-risk Asian singleton pregnant women. We retrospectively analyzed women who delivered a singleton neonate at term at a tertiary center and underwent GCT at 24-28 weeks of gestation between June 2001 and June 2015. The low GCT group was defined as <75 mg/dL and 75-139 mg/dL were control. We compared these two groups of maternal characteristics, small for gestational age neonate (SGA), large for gestational age neonate (LGA), low-birth weight, and macrosomia. The χ 2 test, Fisher's exact test, and Student's t test were used. There were 313 low GCT groups and 4611 control. The low GCT group were younger, had lower prepregnancy body weight, higher stature, and lower prepregnancy body mass index (BMI). After adjusting these variables, the low GCT group had a lower rate of LGA and a higher rate of SGA. Neonatal body weight is more influenced by maternal physique than by low GCT result (standardized coefficient (β); GCT 0.071, height 0.188, prepregnancy BMI 0.143). Neonatal body weight was only slightly influenced by low GCT result, but markedly influenced by maternal physique, such as height and prepregnancy BMI.

Delaunay based algorithm for finding polygonal voids in planar point sets

NASA Astrophysics Data System (ADS)

Alonso, R.; Ojeda, J.; Hitschfeld, N.; Hervías, C.; Campusano, L. E.

2018-01-01

This paper presents a new algorithm to find under-dense regions called voids inside a 2D point set. The algorithm starts from terminal-edges (local longest-edges) in a Delaunay triangulation and builds the largest possible low density terminal-edge regions around them. A terminal-edge region can represent either an entire void or part of a void (subvoid). Using artificial data sets, the case of voids that are detected as several adjacent subvoids is analyzed and four subvoid joining criteria are proposed and evaluated. Since this work is inspired on searches of a more robust, effective and efficient algorithm to find 3D cosmological voids the evaluation of the joining criteria considers this context. However, the design of the algorithm permits its adaption to the requirements of any similar application.

Metabolic profiles, diet, and health practices of championship male and female bodybuilders.

PubMed

Kleiner, S M; Bazzarre, T L; Litchford, M D

1990-07-01

To obtain a more complete view of their general health and health care habits, 27 bodybuilders (19 men and 8 women) competing at the 1988 National Physique Committee's Junior USA Bodybuilding Championships participated in this study. Data pertaining to demographics and pre-competition nutrition, training, health, and drug abuse practices were collected by self-administered and interview surveys and records. Anthropometric and blood pressure measurements and casual blood samples were collected on -site at the competition registration. Multi-drug abuse was reported by 15% to 40% of the subjects, and 20% to 40% of subjects left the drug use questions unanswered. Severe fluid restrictions and dehydrating practices were reported by all subjects. Eleven men and two women agreed to have blood drawn. Plasma glucose values were at the low end of the normal fasting range. Hemoglobin levels were elevated, indicating hypohydration; magnesium levels were slightly low. Percent body fat, estimated by seven-site skinfold measures, was low for both sexes (men, 6.0 +/- 1.8; women, 9.8 +/- 1.5); 75% of the women reported normal menstrual cycles. The men reported high-protein, low-fat hypocaloric diet patterns. Women had a moderate zinc intake and a remarkably deficient calcium intake despite an adequate energy intake. This research demonstrates that bodybuilders partake in a multitude of practices that may place them in high-risk health categories. It is essential that health care workers in contact with bodybuilding athletes intervene and educate them about healthy dietary and training alternatives.

Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brizard, Alain J

Final Technical Report for U.S. Department of Energy Grant No. DE-FG02-09ER55005 Nonlinear FLR Effects in Reduced Fluid Models Alain J. Brizard, Saint Michael's College The above-mentioned DoE grant was used to support research activities by the PI during a sabbatical leave from Saint Michael's College in 2009. The major focus of the work was the role played by guiding-center and gyrocenter (linear and nonlinear) polarization and magnetization effects in understanding transport processes in turbulent magnetized plasmas. The theoretical tools used for this work include Lie-transform perturbation methods and Lagrangian (variational) methods developed by the PI in previous work. The presentmore » final technical report lists (I) the peer-reviewed publications that were written based on work funded by the Grant; (II) invited and contributed conference presentations during the period funded by the Grant; and (III) seminars presented during the period funded by the Grant. I. Peer-reviewed Publications A.J. Brizard and N. Tronko, 2011, Exact momentum conservation for the gyrokinetic Vlasov- Poisson equations, Physics of Plasmas 18 , 082307:1-14 [http://dx.doi.org/10.1063/1.3625554 ]. J. Decker, Y. Peysson, A.J. Brizard, and F.-X. Duthoit, 2010, Orbit-averaged guiding-center Fokker-Planck operator for numerical applications, Physics of Plasmas 17, 112513:1-12 [http://dx.doi.org/10.1063/1.3519514]. A.J. Brizard, 2010, Noether derivation of exact conservation laws for dissipationless reduced fluid models, Physics of Plasmas 17, 112503:1-8 [http://dx.doi.org/10.1063/1.3515303]. F.-X. Duthoit, A.J. Brizard, Y. Peysson, and J. Decker, 2010, Perturbation analysis of trapped particle dynamics in axisymmetric dipole geometry, Physics of Plasmas 17, 102903:1-9 [http://dx.doi.org/10.1063/1.3486554]. A.J. Brizard, 2010, Exact energy conservation laws for full and truncated nonlinear gyrokinetic equations, Physics of Plasmas 17, 042303:1-11 [http://dx.doi.org/10.1063/1.3374428]. A.J. Brizard, J. Decker, Y. Peysson, and F.-X. Duthoit, 2009, Orbit-averaged guiding-center Fokker-Planck operator, Physics of Plasmas 16, 102304:1-9[http://dx.doi.org/10.1063/1.3249627]. A.J. Brizard, 2009, Variational Principles for Reduced Plasma Physics, Journal of Physics: Conference Series 169, 012003 [http://dx.doi.org/10.1088/1742-6596/169/1/012003]. II. Invited and Contributed Conference Presentations A.J. Brizard and N. Tronko, Momentum conservation law for the gyrokinetic Vlasov-Poisson equations, 53rd Annual Meeting of the APS Division of Plasma Physics, Salt Lake City (Utah), November 14-18, 2011. A.J. Brizard, P.J. Morrison, C. Chandre, and E. Tassi, On the road to the Hamiltonian formulation of gyrokinetic theory, 52nd Annual Meeting of the APS Division of Plasma Physics, Chicago (Illinois), November 8-12, 2010. F.-X. Duthoit, A.J. Brizard, Y. Peysson, and J. Decker, Lie-transform perturbation analysis of trapped-particle dynamics in axisymmetric dipole geometry, 2010 International Sherwood Fusion Theory Conference, Seattle (Washington), April 19-21, 2010. N. Tronko and A.J. Brizard, Gyrokinetic momentum conservation law, 2010 International Sherwood Fusion Theory Conference, Seattle (Washington), April 19-21, 2010. C. Chandre and A.J. Brizard, Hamiltonian formulation of reduced Vlasov-Maxwell equations, 50th Annual Meeting of the APS Division of Plasma Physics, Dallas (Texas), November 17-21, 2008. A.J. Brizard, Nonlinear FLR effects in reduced fluid models, Invited Presentation at 11th Easter Plasma Meeting, Torino (Italy), April 15-17, 2009. III. Seminars Reduced Fokker-Planck operators for advanced plasma simulations, seminar given at CEA Cadarache (France), May 25, 2009. Ray phase-space methods in linear mode conversion, seminar given at CPT Luminy (France), April 1, 2009. Old and new methods in gyrokinetic theory, seminar given at CEA Cadarache (France), March 20, 2009. Hamiltonian theory of adiabatic motion of relativistic charged particles, seminar given at CPT Luminy (France), March 11, 2009. Noether method for fluids and plasmas, seminar given at CEA Cadarache (France), February 5, 2009. Nonlinear FLR effects in reduced fluid models, invited speaker at the Journee de la Dynamique Non Lineaire, Centre de Physique Theorique, CNRS Luminy (Marseille, France), June 3, 2008.« less

PEOPLE IN PHYSICS: 'Lady Newton' - an eighteenth century Marquise

NASA Astrophysics Data System (ADS)

Badilescu, Simona

1996-07-01

The contribution of Voltaire and Mme du Châtelet to the diffusion of Newtonian physics in eighteenth century France is outlined. Their most important writings in the realm of physics (Philosophical Letters, Elements de la philosophie de Newton, Institutions de Physique) are analysed and the impact of the new ideas on the traditional Cartesian physics is emphasized. The genesis of the first French translation of Newton's Principia is described. The usefulness of the historically connected stories in the teaching of physics is envisaged.

CFD Simulations of a Ferry in Head Seas

DTIC Science & Technology

2011-03-01

la durée de vie en fatigue globale du navire. Il est important, pour la conception, l’exploitation et la gestion du cycle de ...vibration de frottement qui exerce une contrainte sur la structure de coque primaire et qui a un effet défavorable sur la durée de vie en fatigue globale du ...laquelle ne peut simuler directement la physique du tossage. Le présent rapport contient les résultats d’une étude faisant

Hig Resolution Seismometer Insensitive to Extremely Strong Magnetic Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramovich, Igor A.

A highly sensitive broadband seismic sensor has been developed successfully to be used in beam focusing systems of particale accelerators. The sensor is completely insensitive to extremely strong magnetic fields and to hard radiation conditions that exist at the place of their installation. A unique remote sensor calibration method has been invented and implemented. Several such sensors were sold to LAPP (LAPP-IN2P3/CNRS-Université de Savoie; Laboratoire d'Annecy-le-Vieux de Physique des Particules)

Retirement Kjell Johnsen

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2007-12-05

A l'occasion de son 65me anniversaire plusieurs orateurs (aussi l'ambassadeur de Norvège) remercient Kjell Johnsen, né en juin 1921 en Norvège, pour ses 34 ans de service au Cern et retracent sa vie et son travail. K.Johnsen a pris part aux premières études sur les accélérateurs du futur centre de physique et fut aussi le père et le premier directeur de l'Ecole du Cern sur les accélérateurs (CAS)

Transcendental Meditation

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2005-11-29

K.Wallace, qui vient des Etats Unis, parle des effects physiologiques de la méditation transcendantale. Il a fait son bachelor en physique à l'Université de Los Angeles et son doctorat en physiologie aussi à Los Angeles, mais à l'Institut de Recherche sur le cerveau. Il travaille maintenat à Harvard Medical School ou il continue des recherches biochimiques et physiologiques sur l'application médicale de la méditation transcendantale. Il s'occupe principalement des maladies cardiaques et de hypertension artérielle.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Plusieurs orateurs rendent hommage au grand physicien et scientifique Vladimir Jurko Glaser (1924 - 1984) qui travaillait au Ruder Boscovic Institut à Zagreb avant de venir au Cern en 1957 où il trouvait un poste permanent au département de physique théorique. Walter Tearing, Harry Lehmann,Henry Epstein, Jacques Bros et André Martin font des résumés biographiques de leurs collègue et ami en honorant ses grands qualités d'homme et ses remarquables conquêtes de la science et leurs accomplissement.

Self-reported Health and Well-being Outcomes of ASERE Students

DTIC Science & Technology

2005-07-01

mesure normalisée) des scores légèrement plus faibles dans l’évaluation de la santé physique à la fin du cours comparativement à ceux indiqués avant...faibles après le cours comparativement à ceux obtenus lors de l’évaluation antérieure au cours...Zachariassen, 2000, p. 334). Indeed, the need for control is so great in humans that stress can trigger a variety of behaviors specifically designed to

Effects of Stencil Width on Surface Ocean Geostrophic Velocity and Vorticity Estimation from Gridded Satellite Altimeter Data

DTIC Science & Technology

2012-03-17

Texas at Austin, Austin, Texas, USA. g dq ’Departement de Physique and LPO, Universite de Bretagne V _ /" r5r’ Occidental, Brest ...grid points are used in the calculation, so that the grid spacing is 8 times larger than on the original grid. The 3-point stencil differences are sig...that the difference between narrow and wide stencil estimates increases over that found on the original higher resolution grid. Interpolation of the

Estimates of Surface Drifter Trajectories in the Equatorial Atlantic: A Multi-model Ensemble Approach

DTIC Science & Technology

2012-01-01

Physique des Oceans UMR6523 (CNRS. I B(). IFREMER. IRD). Brest , France C. N. Barron E. Joseph Metzger Naval Research Laboratory, Stennis Space...AF447 flight from Rio to Paris . The airplane disappeared on June 1st 2009 near 3° N and 31° W, and a large international effort was organized to...to Runge-Kutta trajectory integration. The low- pass filter was accomplished by convolving the original (XiCM velocity fields at each time step and

Purity and cleanness of aerogel as a cosmic dust capture medium

NASA Technical Reports Server (NTRS)

Tsou, P.; Fleming, R. H.; Lindley, P. M.; Craig, A. Y.; Blake, D.

1994-01-01

The capability for capturing micrometeoroids intact through laboratory simulations and in space in passive underdense silica aerogel offers a valuable tool for cosmic dust research. The integrity of the sample handling medium can substantially modify the integrity of the sample. Intact capture is a violent hypervelocity event: the integrity of the capturing medium can cause even greater modification of the sample. Doubts of the suitability of silica aerogel as a capture medium were raised at the 20th LPSC, and questions were raised again at the recent workshop on Particle Capture, Recovery, and Velocity Trajectory Measurement Technologies. Assessment of aerogel's volatile components and carbon contents have been made. We report the results of laboratory measurements of the purity and cleanliness of silica aerogel used for several Sample Return Experiments flown on the Get Away Special program.

Ionosphere/microwave beam interaction study. [satellite solar energy conversion

NASA Technical Reports Server (NTRS)

Duncan, L. M.; Gordon, W. E.

1977-01-01

A solar power satellite microwave power density of 20mw sq cm was confirmed as the level where nonlinear interactions may occur in the ionosphere, particularly at 100 km altitude. Radio wave heating at this altitude, produced at the Arecibo Observatory, yielded negative results for radio wave heating of an underdense ionosphere. Overdense heating produced striations in the ionosphere which may cause severe radio frequency interference problems under certain conditions. The effects of thermal self-focusing are shown to be limited severely geographically. The aspect sensitivity of field-aligned striations makes interference-free regions above magnetic latitude about 60 deg. A test program is proposed to simulate the interaction of the SPS beam with the ionosphere, to measure the effects of the interaction on the ionosphere and on communication and navigation systems, and to interpret the results.

Motivational and psychological correlates of bodybuilding dependence

PubMed Central

EMINI, NEIM N.; BOND, MALCOLM J.

2014-01-01

Abstract Background and aims: Exercise may become physically and psychologically maladaptive if taken to extremes. One example is the dependence reported by some individuals who engage in weight training. The current study explored potential psychological, motivational, emotional and behavioural concomitants of bodybuilding dependence, with a particular focus on motives for weight training. Using a path analysis paradigm, putative causal models sought to explain associations among key study variables. Methods: A convenience sample of 101 men aged between 18 and 67 years was assembled from gymnasia in Adelaide, South Australia. Active weight trainers voluntarily completed a questionnaire that included measures of bodybuilding dependence (social dependency, training dependency, and mastery), anger, hostility and aggression, stress and motivations for weight training. Results: Three motives for weight training were identified: mood control, physique anxiety and personal challenge. Of these, personal challenge and mood control were the most directly salient to dependence. Social dependency was particularly relevant to personal challenge, whereas training dependency was associated with both personal challenge and mood control. Mastery demonstrated a direct link with physique anxiety, thus reflecting a unique component of exercise dependence. Conclusions: While it was not possible to determine causality with the available data, the joint roles of variables that influence, or are influenced by, bodybuilding dependence are identified. Results highlight unique motivations for bodybuilding and suggest that dependence could be a result of, and way of coping with, stress manifesting as aggression. A potential framework for future research is provided through the demonstration of plausible causal linkages among these variables. PMID:25317342

Motivational and psychological correlates of bodybuilding dependence.

PubMed

Emini, Neim N; Bond, Malcolm J

2014-09-01

Exercise may become physically and psychologically maladaptive if taken to extremes. One example is the dependence reported by some individuals who engage in weight training. The current study explored potential psychological, motivational, emotional and behavioural concomitants of bodybuilding dependence, with a particular focus on motives for weight training. Using a path analysis paradigm, putative causal models sought to explain associations among key study variables. A convenience sample of 101 men aged between 18 and 67 years was assembled from gymnasia in Adelaide, South Australia. Active weight trainers voluntarily completed a questionnaire that included measures of bodybuilding dependence (social dependency, training dependency, and mastery), anger, hostility and aggression, stress and motivations for weight training. Three motives for weight training were identified: mood control, physique anxiety and personal challenge. Of these, personal challenge and mood control were the most directly salient to dependence. Social dependency was particularly relevant to personal challenge, whereas training dependency was associated with both personal challenge and mood control. Mastery demonstrated a direct link with physique anxiety, thus reflecting a unique component of exercise dependence. While it was not possible to determine causality with the available data, the joint roles of variables that influence, or are influenced by, bodybuilding dependence are identified. RESULTS highlight unique motivations for bodybuilding and suggest that dependence could be a result of, and way of coping with, stress manifesting as aggression. A potential framework for future research is provided through the demonstration of plausible causal linkages among these variables.

Fear of negative appearance evaluation: development and evaluation of a new construct for risk factor work in the field of eating disorders.

PubMed

Lundgren, Jennifer D; Anderson, Drew A; Thompson, Joel Kevin

2004-01-01

The psychometric properties and correlates of a measure designed to assess fear of negative appearance evaluation are presented. In Study 1, 165 college females completed the Fear of Negative Appearance Evaluation Scale [FNAES; Thomas, C.M., Keery, H., Williams, R., & Thompson, J. K. (1998, November). The Fear of Negative Appearance Evaluation Scale: Development and preliminary validation. Paper presented at the annual meeting of the Association for the Advancement of Behavior Therapy, Washington, DC] along with measures of body image, eating disturbance, and depression. Results replicated previous analyses indicating the presence of a single factor, good internal consistency, and significant association with measures of body image and eating disturbance. Additionally, the FNAES accounted for unique variance beyond that explained by general fear of negative evaluation, and other measures of body image and eating disturbance, in the prediction of body shape dysphoria, dietary restraint, and trait anxiety. Study 2 further examined the validity of the FNAES, finding it to correlate significantly with measures of social physique anxiety, body image, eating attitude, and mood. The FNAES did not significantly correlate with body mass index (BMI). Regression analyses found the FNAES to predict levels of body image, eating attitude, and mood beyond variance explained by social physique anxiety. The FNAES appears to measure a conceptually unique aspect of body image that has not been indexed by previous measures and may serve a useful role in risk factor and preventive work.

Nutritional recommendations for water polo.

PubMed

Cox, Gregory R; Mujika, Iñigo; van den Hoogenband, Cees Rein

2014-08-01

Water polo is an aquatic team sport that requires endurance, strength, power, swimming speed, agility, tactical awareness, and specific technical skills, including ball control. Unlike other team sports, few researchers have examined the nutritional habits of water polo athletes or potential dietary strategies that improve performance in water polo match play. Water polo players are typically well muscled, taller athletes; female players display higher levels of adiposity compared with their male counterparts. Positional differences exist: Center players are heavier and have higher body fat levels compared with perimeter players. Knowledge of the physical differences that exist among water polo players offers the advantage of player identification as well as individualizing nutrition strategies to optimize desired physique goals. Individual dietary counseling is warranted to ensure dietary adequacy, and in cases of physique manipulation. Performance in games and during quality workouts is likely to improve by adopting strategies that promote high carbohydrate availability, although research specific to water polo is lacking. A planned approach incorporating strategies to facilitate muscle glycogen refueling and muscle protein synthesis should be implemented following intensified training sessions and matches, particularly when short recovery times are scheduled. Although sweat losses of water polo players are less than what is reported for land-based athletes, specific knowledge allows for appropriate planning of carbohydrate intake strategies for match play and training. Postgame strategies to manage alcohol intake should be developed with input from the senior player group to minimize the negative consequences on recovery and player welfare.

Voyage dans le noir. Trous noirs, matière noire, énergie noire et antimatière [Journey in the dark. Black holes, dark matter, dark energy and antimatter

ScienceCinema

Alvarez-Gaume, Luis; Doser, Michael; Grojean, Chri

2018-05-24

Et si nous faisions avec les physiciens un voyage dans le noir ? De l'astrophysique à la physique des particules les trois noirs, la matière noire, l'énergie noire ou l’antimatière intriguent et fascinent. Que sont ces objets qui bousculent nos idées et qui véhiculent parfois des craintes irraisonnées? Luis Alvarez-Gaume, Michael Doser et Christophe Grojean, physiciens du CERN vous invitent à mettre en lumière (!) les constituants de base de la matière et à explorer les mystères de la physique contemporaine. Une soirée lumineuse pour éclairer des concepts et ne plus avoir peur du noir. [ What if we made a trip to the physicists in the dark? From astrophysics to particle physics the three blacks, dark matter, dark energy or antimatter intrigue and fascinate. What are these objects that jostle our ideas and sometimes convey irrational fears? Luis Alvarez-Gaume, Michael Doser and Christophe Grojean, CERN physicists invite you to highlight (!) The basic constituents of matter and to explore the mysteries of contemporary physics. A bright evening to illuminate concepts and not be afraid of the dark.

Synthese de champs sonores adaptative

NASA Astrophysics Data System (ADS)

Gauthier, Philippe-Aubert

La reproduction de champs acoustiques est une approche physique au probleme technologique de la spatialisation sonore. Cette these concerne l'aspect physique de la reproduction de champs acoustiques. L'objectif principal est l'amelioration de la reproduction de champs acoustiques par "synthese de champs acoustiques" ("Wave Field Synthesis", WFS), une approche connue, basee sur des hypotheses de champ libre, a l'aide du controle actif par l'ajout de capteurs de l'erreur de reproduction et d'une boucle fermee. Un premier chapitre technique (chapitre 4) expose les resultats d'appreciation objective de la WFS par simulations et mesures experimentales. L'effet indesirable de la salle de reproduction sur les qualites objectives de la WFS fut illustre. Une premiere question de recherche fut ensuite abordee (chapitre 5), a savoir s'il est possible de reproduire des champs progressifs en salle dans un paradigme physique de controle actif: cette possibilite fut prouvee. L'approche technique privilegiee, "synthese de champs adaptative" ("Adaptive Wave Field Synthesis" [AWFS]), fut definie, puis simulee (chapitre 6). Cette approche d'AWFS comporte une originalite en controle actif et en reproduction de champs acoustiques: la fonction cout quadratique representant la minimisation des erreurs de reproduction inclut une regularisation de Tikhonov avec solution a priori qui vient de la WFS. L'etude de l'AWFS a l'aide de la decomposition en valeurs singulieres (chapitre 7) a permis de comprendre les mecanismes propres a l'AWFS. C'est la deuxieme principale originalite de la these. L'algorithme FXLMS (LMS et reference filtree) est modifie pour l'AWFS (chapitre 8). Le decouplage du systeme par decomposition en valeurs singulieres est illustre dans le domaine du traitement de signal et l'AWFS basee sur le controle independant des modes de rayonnement est simulee (chapitre 8). Ce qui constitue la troisieme originalite principale de cette these. Ces simulations du traitement de signal montrent l'efficacite des algorithmes et la capacite de l'AWFS a attenuer les erreurs attribuables a des reflexions acoustiques. Le neuvieme chapitre presente des resultats experimentaux d'AWFS. L'objectif etait de valider la methode et d'evaluer les performances de l'AWFS. Un autre algorithme prometteur est aussi teste. Les resultats demontrent la bonne marche de l'AWFS et des algorithmes testes. Autant dans le cas de la reproduction de champs harmoniques que dans le cas de la reproduction de champs a large bande, l'AWFS reduit l'erreur de reproduction de la WFS et les effets indesirables causes par les lieux de reproduction.

Age related changes in pelvis size among adolescent and adult females with reference to parturition from Naraingarh, Haryana (India).

PubMed

Sharma, Krishan; Gupta, Puneet; Shandilya, Shailza

2016-08-01

This research examines the ontogenic patterns of changes in growth during adolescence, pelvis variations and growth during twenties and thirties of age, structural remodeling of pelvis related to childbirth and relationship of pelvis area with physique based on the cross-sectional data on 391 females from the state of Haryana. Peak growth velocity for body height and breadths of skeletal traits occurred between 11 and 12 years, much before mean age of menarche at 13.5 years; while for body weight and body mass index (BMI) occurred between 14 and 15 years, after the mean age of menarche. Untill the age 11 years, 11.87% of growth in stature was remaining, 19.37% for bi-cristal breadth, 25.96% for bi-ischial breadth and 35.82% for pelvic area. The hypothesis of critical value of pelvic width of 240mm at iliocristale for menarche to occur has been only a statistical association. Higher prevalence of malnutrition during pubertal phase than pre- and post-pubertal phases was due to greater nutritional needs during puberty. Among adult females, BMI was very poorly correlated with stature but very strongly correlated with body breadths, body breadth-stature indices and body weight. The body mass and pelvis size continued to change during 20s and first half of 30s. The continued increase of BMI was due to increase in body fat and muscle mass in females 18 years and older. To tease apart age and parturition effects on pelvis variations, the analysis showed that pelvic bones remodeling took place after the first child was born and not after the subsequent births, and it was a sign of childbirth phenotypic plasticity rather than age. Pelvis area was strongly associated with stature, BMI and age. Mean pelvic area of tall females was greater than those of medium and short stature. Females with broad shoulders had significantly greater mean pelvis area than those with narrow shoulders and medium shoulders. Females having thin/lean physique had the smallest mean pelvis area compared to those having medium and obese types of physiques. The stepwise multiple regression analysis revealed that BMI was the major determinant factor (multiple r=0.37) of pelvis area; addition of stature component increased the value of multiple r to 0.50, while addition of age marginally increased multiple r to 0.53. Copyright © 2016 Elsevier GmbH. All rights reserved.

The Scoring of Integrative Complexity as a Tool in Forecasting Adversary Intentions: Three Case Studies

DTIC Science & Technology

2010-04-01

certaines crises internationales. En analysant des documents et des archives sonores remis par des chefs nationaux et des groupes dirigeants, on a constaté...de lettres, de notes officielles, etc., de chefs et de groupes dirigeants identifiés, comme les conseils de ministre ou des équipes de résolution...Voulant conserver le pouvoir, les fidèles de Mugabe ont lancé une série d’attaques physiques contre les chefs et les membres de l’opposition, et ce

Transcendental Meditation

ScienceCinema

None

2017-12-09

K.Wallace, qui vient des Etats Unis, parle des effects physiologiques de la méditation transcendantale. Il a fait son bachelor en physique à l'Université de Los Angeles et son doctorat en physiologie aussi à Los Angeles, mais à l'Institut de Recherche sur le cerveau. Il travaille maintenat à Harvard Medical School ou il continue des recherches biochimiques et physiologiques sur l'application médicale de la méditation transcendantale. Il s'occupe principalement des maladies cardiaques et de hypertension artérielle.

Modelling of Molecular Structures and Properties in Physical Chemistry and Biophysics, Forty-Fourth International Meeting (Modelisation des Structures et Proprietes Moleculaires en Chimie Physique et en Biophysique, Quarante- Quatrieme Reunion Internationale)

DTIC Science & Technology

1989-09-01

pyridone).Previous work on, py/ridimum, pyrazinjumn or pyrimidi im salts Koon 2 -pyrimloone and 2 - pyrimidone salts [43j have shown that some...forces. Acct . r ~[U... •K;.i. LJ , ’ 0, ’’ .t_I ..- .It . ( :.. 2 A VIBRATIONAL MOLECULAR FORCE FIELD FOR .ACROMOLECULA-R MODELLI= Gerard VERGOTENi...microscopic point of view are (1) understanding, ( 2 ) interpretation of experimental results, (3) semiquantitative estimates of experimental results and (4

A scientist born in amiens : jacques rohault (1620-1672) (French Title: Un savant amiénois : jacques rohault (1620-1672))

NASA Astrophysics Data System (ADS)

Le Boeuffle, A.

2004-12-01

Jacques Rohault is born in Amiens town at the beginning of the seventeen century. After the Middle Ages, science try to use nex methods and want to abandon Greek's dogmas. Rohault came to Paris to continue his studies and met J.B. Poquelin (Molière). He became a friend an a supporter of René Descartes. He was a very popular scientist. He practised many experiments in public and writed the book La physique to popularize science.

Statistical study of ionospheric ion beams observed by CLUSTER above the polar caps

NASA Astrophysics Data System (ADS)

Maggiolo, R.; Echim, M.; Fontaine, D.; Teste, A. F.; Jacquey, C.

2009-12-01

Above the polar caps and during prolonged periods of Northward IMF, the Cluster spacecraft detect accelerated ion beams with energies up to a few keV. They are associated with downward precipitating electrons and converging electric field structures indicating that the acceleration is caused by a quasi-static field aligned electric field that can extend to altitudes up to 5 RE (Maggiolo et al. 2006, Teste et al. 2007). Using the AMDA science analysis service provided by the Centre de Données de la Physique des Plasmas (CDPP, http://cdpp.cesr.fr), we have been able to extract from the Cluster ion detectors dataset the time periods when Cluster encounters polar cap local ion beams. 6 years of data have been mined with this tool. Almost 200 events have been found giving new insight on these structures. After a description of the method used for the automatic detection of the beams, we will discuss their statistical properties. We analyze their relation to solar wind and IMF. In particular, we estimate the delay between a Northward/Southward turning of the IMF and the appearance/disappearance of these beams. The characteristics of the particles detected inside these structures as well as their size, orientation and location are also presented. We show that these ion beams are located on magnetic field lines mapping close to the high latitude magnetopause and in the central part of the lobes and that 40 % of them are detected together with hot isotropic ions. These results will be discussed in term of magnetotail configuration during prolonged periods of Northward IMF.

Ingenierie de nanoparticules plasmoniques robustes pour la generation de bulles par laser en vue d'applications biomedicales

NASA Astrophysics Data System (ADS)

Lachaine, Remi

Les chirurgiens generent des bulles dans le corps humain a l'aide d'irradiation laser depuis plusieurs decennies. Ils utilisent ces bulles comme de petits scalpels, leur permettant de faire des incisions precises et localisees. Une des applications de cet outil chirurgical est la perforation cellulaire. Au lieu d'utiliser une aiguille pour perforer la membrane des cellules, il est possible de focaliser des impulsions laser en surface d'une cellule, formant un plasma au point focal du laser et generant une bulle qui perfore la membrane cellulaire. Toutefois, ce procede est assez lent et la perforation massive de cellules in-vivo n'est pas envisageable. Pour accelerer le processus, il est possible d'utiliser des nanoparticules plasmoniques. Ces dernieres agissent comme des nano-antennes qui permettent de concentrer la lumiere sur une echelle nanometrique. La possibilite d'irradier un grand nombre de nanoparticules simultanement a donne un nouvel elan a la generation de bulle comme outil de perforation cellulaire. L'utilisation de nanoparticules dans un contexte biomedical comporte toutefois certains risques. En particulier, la fragmentation de nanoparticules peut augmenter la toxicite du traitement. Dans un cas ideal, il est preferable d'utiliser des nanoparticules qui ne sont pas endommagees par l'irradiation laser. Cette these a pour but de developper une methode d'ingenierie de nanoparticules robustes permettant la generation efficace de bulles a des fins biomedicales. Il est tout d'abord demontre experimentalement que la formation de plasma est bel et bien le mecanisme physique principal menant a la generation de bulles lors de l'irradiation infrarouge (longueur d'onde de 800 nm) et ultrarapide (temps d'impulsion entre 45 fs et 1 ps) de nanoparticules d'or de 100 nm. Pour realiser cette demonstration, une methode pompe-sonde de detection de bulles d'environ 1 mum a ete elaboree. Cette methode a permis de mettre en evidence une difference de taille de 18% entre les bulles generees avec une irradiation de polarisation lineaire par rapport a une polarisation circulaire lorsque la duree d'impulsion etait inferieure a la picoseconde. Pour des impulsions plus longues, il est montre que les tailles de bulles sont independantes de la polarisation des impulsions incidentes. Ce comportement particulier est en accord avec les predictions theoriques qui incluent la formation non-lineaire de plasma et ne peut pas etre explique en considerant uniquement l'absorption des particules. Ensuite, une methode de conception de nanoparticules robustes pour la generation de bulles est elaboree. Cette methode se base sur les proprietes optiques des nanostructures.

The large-scale effect of environment on galactic conformity

NASA Astrophysics Data System (ADS)

Sun, Shuangpeng; Guo, Qi; Wang, Lan; Lacey, Cedric G.; Wang, Jie; Gao, Liang; Pan, Jun

2018-07-01

We use a volume-limited galaxy sample from the Sloan Digital Sky Survey Data Release 7 to explore the dependence of galactic conformity on the large-scale environment, measured on ˜4 Mpc scales. We find that the star formation activity of neighbour galaxies depends more strongly on the environment than on the activity of their primary galaxies. In underdense regions most neighbour galaxies tend to be active, while in overdense regions neighbour galaxies are mostly passive, regardless of the activity of their primary galaxies. At a given stellar mass, passive primary galaxies reside in higher density regions than active primary galaxies, leading to the apparently strong conformity signal. The dependence of the activity of neighbour galaxies on environment can be explained by the corresponding dependence of the fraction of satellite galaxies. Similar results are found for galaxies in a semi-analytical model, suggesting that no new physics is required to explain the observed large-scale conformity.

Surveyor 3 Preliminary Science Results

NASA Technical Reports Server (NTRS)

1967-01-01

Surveyor III soft-landed on the Moon at 00:04 GMT on April 20, 1967. Data obtained have significantly increased our knowledge of the Moon. The Surveyor III spacecraft was similar to Surveyor I; the only major change in scientific instrumentation was the addition of a soil mechanics surface sampler. Surveyor III results at this preliminary evaluation of data give valuable information about the relation between the surface skin of under-dense material responsible for the photometric properties and the deeper layers of material whose properties resemble those of ordinary terrestrial soils. In addition, they provide new insight into the relation between the general lunar surface as seen by Surveyor I and the interior of a large subdued crater. The new results have also contributed to our understanding of the mechanism of downhill transport. Many critical questions cannot, however, be answered until final reduction of experimental data.

Environments of z~0.2 Star Forming Galaxies: Building on the Citizen Science Discovery of the Green Peas

NASA Astrophysics Data System (ADS)

Cardamone, Carolin; Cappelluti, Nico; Powell, Meredith; Urry, Meg; Galaxy Zoo Science Team

2018-01-01

‘Green Pea’ galaxies, discovered in the Galaxy Zoo citizen science project, are rare low-mass (M < 1 x 1010 M⊙) galaxies, experiencing an episode of compact, relatively low-metalicity (z ≈ 1/5 z⊙), intense starformation (3-60 M⊙/yr). While their spectra have been investigated in a wide-array of follow-up studies, a detailed study of their environments is missing. Two-point correlation functions have been used to show the environmental dependence of an array of galaxy properties (eg., mass, luminosity, color, star formation, and morphology). In this study, we present a cross-correlation analysis between the Green Peas and the Luminous Red Galaxies throughout the SDSS footprint, and we find that the population of Green Peas at 0.11

Cosmology with void-galaxy correlations.

PubMed

Hamaus, Nico; Wandelt, Benjamin D; Sutter, P M; Lavaux, Guilhem; Warren, Michael S

2014-01-31

Galaxy bias, the unknown relationship between the clustering of galaxies and the underlying dark matter density field is a major hurdle for cosmological inference from large-scale structure. While traditional analyses focus on the absolute clustering amplitude of high-density regions mapped out by galaxy surveys, we propose a relative measurement that compares those to the underdense regions, cosmic voids. On the basis of realistic mock catalogs we demonstrate that cross correlating galaxies and voids opens up the possibility to calibrate galaxy bias and to define a static ruler thanks to the observable geometric nature of voids. We illustrate how the clustering of voids is related to mass compensation and show that volume-exclusion significantly reduces the degree of stochasticity in their spatial distribution. Extracting the spherically averaged distribution of galaxies inside voids from their cross correlations reveals a remarkable concordance with the mass-density profile of voids.

Reducing the number of templates for aligned-spin compact binary coalescence gravitational wave searches using metric-agnostic template nudging

NASA Astrophysics Data System (ADS)

Indik, Nathaniel; Fehrmann, Henning; Harke, Franz; Krishnan, Badri; Nielsen, Alex B.

2018-06-01

Efficient multidimensional template placement is crucial in computationally intensive matched-filtering searches for gravitational waves (GWs). Here, we implement the neighboring cell algorithm (NCA) to improve the detection volume of an existing compact binary coalescence (CBC) template bank. This algorithm has already been successfully applied for a binary millisecond pulsar search in data from the Fermi satellite. It repositions templates from overdense regions to underdense regions and reduces the number of templates that would have been required by a stochastic method to achieve the same detection volume. Our method is readily generalizable to other CBC parameter spaces. Here we apply this method to the aligned-single-spin neutron star-black hole binary coalescence inspiral-merger-ringdown gravitational wave parameter space. We show that the template nudging algorithm can attain the equivalent effectualness of the stochastic method with 12% fewer templates.

Effects of stellar evolution and ionizing radiation on the environments of massive stars

NASA Astrophysics Data System (ADS)

Mackey, J.; Langer, N.; Mohamed, S.; Gvaramadze, V. V.; Neilson, H. R.; Meyer, D. M.-A.

2014-09-01

We discuss two important effects for the astrospheres of runaway stars: the propagation of ionizing photons far beyond the astropause, and the rapid evolution of massive stars (and their winds) near the end of their lives. Hot stars emit ionizing photons with associated photoheating that has a significant dynamical effect on their surroundings. 3-D simulations show that H ii regions around runaway O stars drive expanding conical shells and leave underdense wakes in the medium they pass through. For late O stars this feedback to the interstellar medium is more important than that from stellar winds. Late in life, O stars evolve to cool red supergiants more rapidly than their environment can react, producing transient circumstellar structures such as double bow shocks. This provides an explanation for the bow shock and linear bar-shaped structure observed around Betelgeuse.

U.S. truck driver anthropometric study and multivariate anthropometric models for cab designs.

PubMed

Guan, Jinhua; Hsiao, Hongwei; Bradtmiller, Bruce; Kau, Tsui-Ying; Reed, Matthew R; Jahns, Steven K; Loczi, Josef; Hardee, H Lenora; Piamonte, Dominic Paul T

2012-10-01

This study presents data from a large-scale anthropometric study of U.S. truck drivers and the multivariate anthropometric models developed for the design of next-generation truck cabs. Up-to-date anthropometric information of the U.S. truck driver population is needed for the design of safe and ergonomically efficient truck cabs. We collected 35 anthropometric dimensions for 1,950 truck drivers (1,779 males and 171 females) across the continental United States using a sampling plan designed to capture the appropriate ethnic, gender, and age distributions of the truck driver population. Truck drivers are heavier than the U.S.general population, with a difference in mean body weight of 13.5 kg for males and 15.4 kg for females. They are also different in physique from the U.S. general population. In addition, the current truck drivers are heavier and different in physique compared to their counterparts of 25 to 30 years ago. The data obtained in this study provide more accurate anthropometric information for cab designs than do the current U.S. general population data or truck driver data collected 25 to 30 years ago. Multivariate anthropometric models, spanning 95% of the current truck driver population on the basis of a set of 12 anthropometric measurements, have been developed to facilitate future cab designs. The up-to-date truck driver anthropometric data and multivariate anthropometric models will benefit the design of future truck cabs which, in turn, will help promote the safety and health of the U.S. truck drivers.

Recognition of body image and food behavior factors among middle school students in San Francisco area

PubMed Central

2007-01-01

The purpose of this study was to determine the recognition of body image and food behavior factors according to the BMI. The subjects of this study were 242 7th grade students resided in San Francisco area. The degree of recognition for self-estimated physique of subjects by gender and by race showed no significant differences by gender but significant differences by race, showing that 20.0% was considered as underweight in Asian and 7.5% was considered as underweight in White students. This showed the same tendency as actual physique status (BMI). Also, the ratio of being recognized as more than overweight was 17.3% in Asian, 23.3% in Hispanic, and 13.4% in White students. In case of female students, the ratio of dieting experience was 63.3%, and 49.3% of White students and 63.3% of Hispanic students experienced dieting. In case of students answered not healthy, their body weight were significantly higher than those answered as healthy, and the BMI was also over 19, showing significant differences. Thus cases that answered as not healthy had greater body weight and BMI. Also it showed that frequent dieting experience is related to higher height and weight. The analysis of food behavior factors perceived by body shape showed that the group perceived itself as overweight consumed more 'fast food' but had low scores in 'vegetables' intake, with frequent intake of 'soda' and tendency to 'overeat'. Also, the tendency for 'balanced life' was significantly lower and for skipping breakfast was significantly higher, suggesting problematic food behavior. PMID:20535383

Agression sexuelle et violence dans les relations amoureuses : Le rôle médiateur du stress post-traumatique

PubMed Central

Hébert, Martine; Daspe, Marie-Ève; Blais, Martin; Lavoie, Francine; Guerrier, Mireille

2017-01-01

Résumé Cette étude vise à documenter le rôle médiateur des symptômes de stress post-traumatique (SSPT) dans le lien entre l’agression sexuelle et différentes formes de victimisation vécues dans le contexte de relations amoureuses. L’étude se fonde sur l’Enquête sur les parcours amoureux des jeunes (PAJ), réalisée au sein de 34 écoles secondaires du Québec. Les jeunes ont rempli un questionnaire portant sur leurs expériences de victimisation, y compris l’agression sexuelle vécue pendant l’enfance et la violence psychologique, physique et sexuelle vécue au sein de leurs relations amoureuses dans les 12 derniers mois. Les SSPT ont été évalués à l’aide du UCLA PTSD Index. Sur un total de 8 194 adolescents, 15% des filles et 4% des garçons ont rapporté avoir vécu une agression sexuelle. Les résultats des analyses acheminatoires semblent indiquer que le fait d’avoir été victime d’agression sexuelle est associé à davantage de SSPT et qu’en retour, les SSPT sont positivement associés à la violence psychologique, physique et sexuelle subie de la part d’un partenaire amoureux. Cette étude comporte des implications pratiques pour la prévention et l’intervention sur le plan de la violence dans les relations amoureuses chez les victimes d’agression sexuelle. PMID:29321695

Do Bodybuilders Use Evidence-Based Nutrition Strategies to Manipulate Physique?

PubMed Central

Gifford, Janelle; Estermann, Frederico

2017-01-01

Competitive bodybuilders undergo strict dietary and training practices to achieve an extremely lean and muscular physique. The purpose of this study was to identify and describe different dietary strategies used by bodybuilders, their rationale, and the sources of information from which these strategies are gathered. In-depth interviews were conducted with seven experienced (10.4 ± 3.4 years bodybuilding experience), male, natural bodybuilders. Participants were asked about training, dietary and supplement practices, and information resources for bodybuilding strategies. Interviews were transcribed verbatim and analyzed using qualitative content analysis. During the off-season, energy intake was higher and less restricted than during the in-season to aid in muscle hypertrophy. There was a focus on high protein intake with adequate carbohydrate to permit high training loads. To create an energy deficit and loss of fat mass, energy intake was gradually and progressively reduced during the in-season via a reduction in carbohydrate and fat intake. The rationale for weekly higher carbohydrate refeed days was to offset declines in metabolic rate and fatigue, while in the final “peak week” before competition, the reasoning for fluid and sodium manipulation and carbohydrate loading was to enhance the appearance of leanness and vascularity. Other bodybuilders, coaches and the internet were significant sources of information. Despite the common perception of extreme, non-evidence-based regimens, these bodybuilders reported predominantly using strategies which are recognized as evidence-based, developed over many years of experience. Additionally, novel strategies such as weekly refeed days to enhance fat loss, and sodium and fluid manipulation, warrant further investigation to evaluate their efficacy and safety.

Studies of human physique and sexual attractiveness: sexual preferences of men and women in China.

PubMed

Dixson, Barnaby J; Dixson, Alan F; Li, Baoguo; Anderson, M J

2007-01-01

Men and women at Northwest University (n = 631), Xi'an, China, were asked to rate the attractiveness of male or female figures manipulated to vary somatotype, waist-to-hip ratio (WHR), secondary sexual traits, and other features. In study 1, women rated the average masculine somatotype as most attractive, followed by the mesomorphic (muscular), ectomorphic (slim), and endomorphic (heavily built) somatotypes, in descending order of preference. In study 2, the amount and distribution of masculine trunk (chest and abdominal) hair were altered progressively in a series of front-posed figures. Women rated figures with no or little trunk hair as most attractive. Study 3 assessed the attractiveness of front-posed male figures which varied only in length of their nonerect penis. Numerical ratings for this trait were low, but moderate lengthening of the penis (22% or 33% above average) resulted in a significant increase in scores for attractiveness. In study 4, Chinese men rated the attractiveness of back-posed female images varying in waist-to-hip ratio (WHR from 0.5-1.0). The 0.6 WHR figure was most preferred, followed by 0.7, while figures with higher ratios (0.9 or 1.0) were significantly less attractive. Study 5 rated the attractiveness of female skin color: men expressed a marked preference for images which were lighter in color, as compared to images of average or darker skin colors. These results, the first of their kind reported for a Chinese population, support the view that sexual selection has influenced the evolution of human physique and sexual attractiveness in men and women.

Still life with less: North Korean young adult defectors in South Korea show continued poor nutrition and physique.

PubMed

Choi, Seul Ki; Park, Sang Min; Joung, Hyojee

2010-04-01

North Korean defectors who settle in South Korea have experienced severe food shortage and transition of food environment which could affect their health status. However, little is known about their anthropometric measurements and dietary intake after settlement in South Korea. The purpose of this study is to compare anthropometric measurements and dietary intake between North Korean young adults who defected to South Korea and those of South Koreans. We hypothesized that North Korean young adults' physiques and dietary intake would be poorer than that of South Koreans. We compared anthropometric measurements and dietary intake from 3-day food records in a cross-sectional study of 103 North Korean young adult defectors, aged 12 to 24 and 309 South Korean subjects. North Korean subjects were significantly shorter (4.9 to 10.8 cm) and lighter (6.0 to 12.5 kg) than the control group. Body mass index were significantly different between North and South Korean groups only in men. North Korean young adult defectors had lower mean daily intakes of energy and most nutrients and food groups compared to the control group, while North Korean subjects had higher nutrient density diet than that of South Koreans. The proportion of subjects who had dietary intakes of nutrients of less than the Estimated Average Requirement was higher in North Korean subjects than in controls except for in the cases of vitamin A and vitamin C. In conclusion, we recommend providing nutrition support programs for North Korean young adult defectors to secure adequate nutrient intake.

Social physique anxiety and disturbed eating attitudes and behaviors in adolescents: moderating effects of sport, sport-related characteristics, and gender.

PubMed

Lanfranchi, Marie-Christine; Maïano, Christophe; Morin, Alexandre J S; Therme, Pierre

2015-02-01

The involvement of adolescents presenting high levels of social physique anxiety (SPA) in sport practice has been hypothesized as potentially problematic in terms of being associated with disturbed eating attitudes and behaviors (DEAB). Indeed, sport practice itself has been reported to be associated with higher levels of SPA and DEAB, and sport settings may sometimes promote unhealthy life habits. Nevertheless, current studies are few and present several limitations. The objective of the present study was to examine these relationships among adolescents involved or not in various types (i.e., leanness and individual) and contexts (i.e., organized and competitive) of sport practice. The sample included 766 French adolescents (337 boys and 429 girls), aged between 11 and 18 years, involved (n = 335) or not (n = 431) in sport practice. SPA and DEAB were assessed using French adaptations of the SPA scale and the Eating Attitudes Test-26. The results reveal a significant and positive association between SPA and the DEAB scales. Furthermore, they show a positive relationship between SPA and (a) vomiting-purging behaviors in adolescents involved in individual sports and (b) generic DEAB (i.e., a subscale covering fear of getting fat, food preoccupation, and eating-related guilt), particularly in adolescents involved in individual sports. The relationship between SPA and DEAB does not differ according to adolescents' involvement in sport practice or according to their involvement in organized, competitive, or leanness sport practice more specifically. However, higher levels of SPA and DEAB were observed in adolescents involved in individual sports.

Nutritional and environmental studies on an ocean-going oil tanker. 3. Energy balances and physique

PubMed Central

Eddy, T. P.; Stock, Anne L.; Wheeler, Erica F.

1971-01-01

Eddy, T. P., Stock, Anne L., and Wheeler, Erica F. (1971).Brit. J. industr. Med.,28, 330-341. Nutritional and environmental studies on an ocean-going oil tanker. 3. Energy balances and physique. During the voyage of the oil tanker S.S. Esso Newcastle to the Persian Gulf(July to August, 1967) the average dietary intake of the whole ship's complement was measured on eight days at different periods of the voyage. In addition, the individual intakes of six subjects (three crew and three students) were measured on three occasions over periods of three days. Estimates were also made of the energy expenditures of three members of the crew and body weight and skinfold thickness were measured. Energy expenditure balanced energy intake in two of the crew members investigated. In the third crew subject, expenditure exceeded intake and there was a slight loss of weight. Two out of the three student subjects showed a significant gain in weight by the end of the voyage. The average calorie intake for the ship was 15·07 megajoules (MJ) (3600 kcal) per man per day (of which 13·23 MJ (3160 kcal) were derived from non-alcoholic sources). This is the United Kingdom recommended intake for very active men. Issues on the Esso Newcastle were 18·83 MJ (4500 kcal)/man/day; the difference between provision and consumption was found to be similar to that reported for Scandinavian vessels. Though the crew tended to be heavier than British landsmen, they did not appear to be abnormally fat. Weight was attributable to muscularity. PMID:5124833

Cumulants and large deviations of the current through non-equilibrium steady states

NASA Astrophysics Data System (ADS)

Bodineau, Thierry; Derrida, Bernard

2007-06-01

Using a generalisation of detailed balance for systems maintained out of equilibrium by contact with 2 reservoirs at unequal temperatures or at unequal densities, one can recover the fluctuation theorem for the large deviation function of the current. For large diffusive systems, we show how the large deviation function of the current can be computed using a simple additivity principle. The validity of this additivity principle and the occurrence of phase transitions are discussed in the framework of the macroscopic fluctuation theory. To cite this article: T. Bodineau, B. Derrida, C. R. Physique 8 (2007).

Real-Time Physiological and Psycho-Physiological Status Monitoring (Suivi en Temps reel de l’Etat Physiologique et Psycho-Physiologique)

DTIC Science & Technology

2010-07-01

des Maquis du Grésivaudan 38702 La Tronche Cedex Phone: +33 4 7663 6975 Fax: +33 4 7663 6945 email: lionelbourdon@crssa.net VC...imassa.fr ICT Chantal JIMENEZ CRSSA/Unité de l’Exercice Physique & Hydromineral 24, av. des Maquis du Grésivaudan BP 87 38702 La Tronche Cedex...d’un état physiologique associé à une mesure de fiabilité des données, etc. Le chapitre du Dr. Gunga énumère les méthodologies d’évaluation des

Retirement Kjell Johnsen

ScienceCinema

None

2017-12-09

A l'occasion de son 65me anniversaire plusieurs orateurs (aussi l'ambassadeur de Norvège) remercient Kjell Johnsen, né en juin 1921 en Norvège, pour ses 34 ans de service au Cern et retracent sa vie et son travail. K.Johnsen a pris part aux premières études sur les accélérateurs du futur centre de physique et fut aussi le père et le premier directeur de l'Ecole du Cern sur les accélérateurs (CAS)

The Problem of Preconcentration of Uranium Ores by Physical Processes; LES PROBLEMES DE LA PRECONCENTRATION DES MINERAIS D'URANIUM PAR VOIE PHYSIQUE. LE TRIAGE ELECTRONIQUE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vuchot, L.; Ginocchio, A. et al.

1959-10-31

As uranium ores, like most other ores, are not definite substances which can be treated directly for the production of the metal, the ores must be concentrated. The common physical processes used for all ores, such as sieving, gravimetric separation, flotation, electromagnetic separation, and electrostatic separation, are applicable to the beneficiation of uranium. The radioactivity of uranium ores has led to a radiometric method for the concentration. This method is described in detail. As an example, the preconcentration of Forez ores is discussed. (J.S.R.)

Modelling of Molecular Structures and Properties. Proceedings of the International Meeting of Physical Chemistry on Modeling of Molecular Structures and Properties in Physical Chemistry and Biophysics Organized by the Division de Chimie Physique of the Societe Francaise de Chimie Held in Nancy, France on 11-15 September 1989

DTIC Science & Technology

1990-01-01

expert systems, "intelligent" computer-aided instruction , symbolic learning . These aspects will be discussed, focusing on the specific problems the...VLSI chips) according to preliminary specifications. Finally ES are also used in computer-aided instruction (CAI) due to their ability of... instructions to process controllers), academic teaching (for mathematics , physics, foreign language, etc.). Domains of application The different

Dynamique d'un oscillateur photoréfractif : instabilités et analogie avec la loi de Curie-Weiss

NASA Astrophysics Data System (ADS)

Mathey, P.; Odoulov, S. G.; Rytz, D.

2002-06-01

La dynamique et l'état stationnaire du faisceau issu d'une cavité oscillante comprenant un cristal non-linéaire de titanate de baryum utilisé en tant que miroir à conjugaison de phase sont étudiés. Le paramètre du système étant le gain du milieu non-linéaire, les dépendances de l'intensité de l'oscillation et de l'inverse du temps de réponse sont similaires aux lois de Curie en physique du solide.

Using hegemonic masculinity to explain gay male attraction to muscular and athletic men.

PubMed

Lanzieri, Nicholas; Hildebrandt, Tom

2011-01-01

This article reviews relevant research on male homosexual attraction. Utilizing masculinity as its theoretical frame, the authors use childhood experiences with both fathers and peers, the gay community's inculcation of heteronormative ideologies, and the gay media's adherence to masculine prototypes, to provide causal explanations for the appeal of muscular, lean, and athletic physiques. While the authors acknowledge that not all individuals within the gay community look toward muscularity and athleticism as the primary components of attractiveness, it nonetheless remains important to examine the theoretical perspectives that may explain the appeal of this specific aesthetic.

Shin Clearance in the Hawk Mk115

DTIC Science & Technology

2008-01-01

represented by the Minister of National Defence, 2008 © Sa Majesté la Reine (en droit du Canada), telle que représentée par le ministre de la Défense... de sélection anthropométrique pour les pilotes. La nouvelle norme base l’acceptation ou le rejet des candidats selon qu’ils sont physiquement...compatibles avec les postes de pilotage de la flotte; la norme précédente n’était pas aussi spécifique. En conséquence, la compatibilité des élèves pilotes

Relaxation plastique d'un film mince par émission de dislocations filantes vis

NASA Astrophysics Data System (ADS)

Bonnet, Roland; Youssef, Sami; Neily, Salem; Gutakowskii, A. K.

2008-03-01

The system formed by a thin film coherent with a crystalline substrate can relax its internal energy by annealing. Threading dislocations emitted after ten minutes annealing at 350 °C of the Si 0.68Ge 0.32/Si(001) heterostructure are observed in transmission electron microscopy, and then identified by comparison to simulated images of angular dislocations placed in a semi infinite medium. They are of screw character, which explains the rapid coverage of the interface by 60° dislocations oriented <110>. To cite this article: R. Bonnet et al., C. R. Physique 9 (2008).

Comprendre. La détection des ondes gravitationnelles

NASA Astrophysics Data System (ADS)

Man, Catherine Nary

2017-12-01

Détecter les ondes gravitationnelles sur Terre est un défi fou relevé depuis les années 80. Cette infime vibration de l'espacetemps chère à Einstein et prédite par lui il y a plus de cent ans, est enfin mesurée par trois interféromètres géants dont un européen Virgo et deux américains LIGO, tous trois mis au point depuis presque deux décennies et travaillant en étroite collaboration dans tous les domaines de la physique.

[Comparative study of retention of a Zn phosphate cement and 4-META].

PubMed

Maroto Garcia, J

1990-12-01

The recent appearance, in the market of the supercements, suggest to us, news concepts of retention-adhesion, of our preparations, that they are going to put in to the mouth. Between his applications, we have the cementation of crowns, post or dowels, adhesive-prosthesis, and inlays. According to the manufactures, the long duration of the bond power, his great physiques properties, and his easy management, gives to this products a good conditions, to use in the mouth. The present report to prove in vitro, the retentive capacity on the dentine without treatment, and metal.

Memorial V.J.Glaser

ScienceCinema

None

2017-12-09

Plusieurs orateurs rendent hommage au grand physicien et scientifique Vladimir Jurko Glaser (1924 - 1984) qui travaillait au Ruder Boscovic Institut à Zagreb avant de venir au Cern en 1957 où il trouvait un poste permanent au département de physique théorique. Walter Tearing, Harry Lehmann,Henry Epstein, Jacques Bros et André Martin font des résumés biographiques de leurs collègue et ami en honorant ses grands qualités d'homme et ses remarquables conquêtes de la science et leurs accomplissement.

Traitements didactiques preventifs d'un type de conceptions erronees en sciences physiques chez des eleves du secondaire

NASA Astrophysics Data System (ADS)

Blondin, Andre

Dans un contexte constructiviste, les connaissances anterieures d'un individu sont essentielles a la construction de nouvelles connaissances. Quelle qu'en soit la source (certaines de ces connaissances ont ete elaborees en classe, d'autres ont ete elaborees par interaction personnelle de l'individu avec son environnement physique et social), ces connaissances, une fois acquises, constituent les matieres premieres de l'elaboration des nouvelles conceptions de cet individu. Generalement, cette influence est consideree comme positive. Cependant, dans un milieu scolaire ou l'apprentissage de certaines conceptions enchassees dans un programme d'etudes et enterinees par l'ensemble d'une communaute est obligatoire, certaines connaissances anterieures peuvent entraver la construction des conceptions exigees par la communaute. La litterature abonde de tels exemples. Cependant, certaines connaissances anterieures, en soi tout a fait conformes a l'Heritage, peuvent aussi, parce qu'utilisees de facon non pertinente, entraver la construction d'une conception exigee par la communaute. Ici, la litterature nous donne peu d'exemples de ce type, mais nous en fournirons quelques-uns dans le cadre theorique, et ce sera un d'entre eux qui servira de base a nos propos. En effet, une grande proportion d'eleves inscrits a un cours de sciences physiques de la quatrieme secondaire, en reponse a un probleme deja solutionne durant l'annee et redonne lors d'un examen sommatif, "Pourquoi la Lune nous montre-t-elle toujours la meme face?", attribue principalement la cause de ce phenomene a la rotation de la Terre sur son axe. En tant que responsable de l'enseignement de ce programme d'etudes, plusieurs questions nous sont venues a l'esprit, entre autres, comment, dans un contexte constructiviste, est-il possible de reduire chez un eleve, l'impact de cette connaissance anterieure dans l'elaboration de la solution et ainsi prevenir la construction d'une conception erronee? Nous avons teste nos hypotheses avec la cohorte suivante d'eleves chez qui se repetaient les memes conditions d'apprentissage. Nous avons utilise le design de recherche "posttest only" de Campbell et Stanley. En mai, apres le moment prevu dans la planification du programme pour donner le probleme aux eleves, nous avons suggere deux facons differentes de reviser la solution de ce probleme. Les eleves du premier groupe experimental ont revise sans que soit activee la connaissance anterieure apprehendee de la rotation de la Terre. Les eleves du deuxieme groupe experimental ont ete confrontes, par des questions et une simulation, au fait que la rotation de la Terre n'est pas une connaissance pertinente pour resoudre le probleme. Les groupes temoins et les groupes experimentaux ont ete choisis au hasard dans le bassin des ecoles secondaires de la commission scolaire. (Abstract shortened by UMI.)

Etudes physiques des mélanges eau-cryoprotecteurs

NASA Astrophysics Data System (ADS)

Vassoille, R.; Perez, J.

The aim of the following review is to present the most important studies concerning the physical properties of water-solutes mixtures used in cryobiology. Cryobiology is a branch of biology which deals with the very low temperature behaviour of cells. This technique is developed today in several directions. The creation of banks of cells and perhaps in a short time of small organs, is the purpose of much research in this domain. Before freezing, living cells are generally put in a solution containing one or more solutes. The role of these solutes is to protect the cells against damage due to crystallization of water (cryoprotectors). The mechanisms of cryoprotection are not well known ; nevertheless the vitreous state formation during cooling is often invoked. So, it is possible to avoid crystallization damage such as mechanical strain (due to an increase of volume of about 10 %) and salt effects (due to osmotic pressure). The conditions in which the vitreous state is obtained, maintained during cooling, storage at low temperature and rewarming can be defined by physical studies presented in the following review. Le présent travail est essentiellement une revue bibliographique des principales études physiques qui ont été réalisées avec des solutions de composés habituellement employés en cryobiologie. La cryobiologie est une branche de la biologie qui s'intéresse au comportement des cellules à basse température. Cette discipline est actuellement en plein développement dans des domaines très divers. Son principal but est la création de banques de cellules de plus en plus complexes avec comme perspective la conservation des organes. Les cellules vivantes sont généralement placées avant congélation dans une solution contenant divers composés dont le rôle est de protéger les cellules contre les effets de la cristallisation de l'eau. L'action protectrice de ces cryoprotecteurs est encore mal connue; cependant, la formation d'un état vitreux lors du refroidissement est souvent invoquée. Ainsi, il est possible d'éviter les dommages liés à la cristallisation : contrainte mécanique due à l'augmentation de volume, effets de sel dus à l'existence d'un gradient de pression osmotique de part et d'autre de la membrane cellulaire. Les conditions d'obtention et de maintien de cet état vitreux lors des opérations de congélation peuvent être définies par des études physiques dont nous proposons une revue.

Influence of subject presentation on interpretation of body composition change after 6 months of self-selected training and diet in athletic males.

PubMed

Kerr, Ava D; Slater, Gary J; Byrne, Nuala M

2018-06-01

High precision body composition assessment methods accurately monitor physique traits in athletes. The acute impact of subject presentation (ad libitum food and fluid intake plus physical activity) on body composition estimation using field and laboratory methods has been quantified, but the impact on interpretation of longitudinal change is unknown. This study evaluated the impact of athlete presentation (standardised versus non-standardised) on interpretation of change in physique traits over time. Thirty athletic males (31.2 ± 7.5 years; 182.2 ± 6.5 cm; 91.7 ± 10.3 kg; 27.6 ± 2.6 kg/m 2 ) underwent two testing sessions on 1 day including surface anthropometry, dual-energy X-ray absorptiometry (DXA), bioelectrical impedance spectroscopy (BIS) and air displacement plethysmography (via the BOD POD), with combinations of these used to establish three-compartment (3C) and four-compartment (4C) models. Tests were conducted after an overnight fast (BASEam) and ~ 7 h later after ad libitum food/fluid and physical activity (BASEpm). This procedure was repeated 6 months later (POSTam and POSTpm). Magnitude of changes in the mean was assessed by standardisation. After 6 months of self-selected training and diet, standardised presentation testing (BASEam to POSTam) identified trivial changes from the smallest worthwhile effect (SWE) in fat-free mass (FFM) and fat mass (FM) for all methods except for BIS (FM) where there was a large change (7.2%) from the SWE. Non-standardised follow-up testing (BASEam to POSTpm) showed trivial changes from the SWE except for small changes in FFM (BOD POD) of 1.1%, and in FM (3C and 4C models) of 6.4 and 3.5%. Large changes from the SWE were found in FFM (BIS, 3C and 4C models) of 2.2, 1.8 and 1.8% and in FM (BIS) of 6.4%. Non-standardised presentation testing (BASEpm to POSTpm) identified trivial changes from the SWE in FFM except for BIS which was small (1.1%). A moderate change from the SWE was found for BOD POD (3.3%) and large for BIS (9.4%) in FM estimations. Changes in body composition utilising non-standardised presentation were more substantial and often in the opposite direction to those identified using standardised presentation, causing misinterpretation of change in physique traits. Standardised presentation prior to body composition assessment for athletic populations should be advocated to enhance interpretation of true change.

PHENIX Collaboration

NASA Astrophysics Data System (ADS)

Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Al-Ta'ani, H.; Alexander, J.; Alfred, M.; Andrews, K. R.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Appelt, E.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bai, X.; Baksay, G.; Baksay, L.; Baldisseri, A.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belikov, S.; Belmont, R.; Ben-Benjamin, J.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Bing, X.; Black, D.; Blau, D. S.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Broxmeyer, D.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Castera, P.; Chang, B. S.; Chang, W. C.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cole, B. A.; Comets, M. P.; Conesa del Valle, Z.; Connors, M.; Constantin, P.; Cronin, N.; Crossette, N.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; Daugherity, M. S.; David, G.; Dayananda, M. K.; Deaton, M. B.; DeBlasio, K.; Dehmelt, K.; Delagrange, H.; Denisov, A.; d'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Do, J. H.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gadrat, S.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guo, L.; Guragain, H.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Han, S. Y.; Hanks, J.; Harada, H.; Harper, C.; Hartouni, E. P.; Haruna, K.; Hasegawa, S.; Hashimoto, K.; Haslum, E.; Hayano, R.; Hayashi, S.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Hollis, R. S.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Hoshino, T.; Huang, J.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imazu, Y.; Imrek, J.; Inaba, M.; Inoue, Y.; Iordanova, A.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isinhue, A.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Ivanishchev, D.; Iwanaga, Y.; Jacak, B. V.; Javani, M.; Jeon, S. J.; Jezghani, M.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; John, D.; Johnson, B. M.; Jones, T.; Joo, E.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kanda, S.; Kaneta, M.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kihara, K.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, H.-J.; Kim, H. J.; Kim, K.-B.; Kim, M.; Kim, S. H.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klatsky, J.; Klay, J.; Klein-Boesing, C.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kochenda, L.; Kochetkov, V.; Kofarago, M.; Komatsu, Y.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Krizek, F.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Layton, D.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, G. H.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, S. H.; Lee, S. R.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Leitner, E.; Lenzi, B.; Lewis, B.; Li, X.; Lichtenwalner, P.; Liebing, P.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Ma, M.; Malakhov, A.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Maruyama, T.; Mašek, L.; Masui, H.; Masumoto, S.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Midori, J.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, A. J.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, D. K.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Miyachi, Y.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, H. J.; Moon, T.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moskowitz, M.; Motschwiller, S.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Nattrass, C.; Nederlof, A.; Netrakanti, P. K.; Newby, J.; Nguyen, M.; Nihashi, M.; Niida, T.; Norman, B. E.; Nouicer, R.; Novak, T.; Novitzky, N.; Nukariya, A.; Nyanin, A. S.; Oakley, C.; Obayashi, H.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Oide, H.; Oka, M.; Okada, K.; Omiwade, O. O.; Onuki, Y.; Orjuela Koop, J. D.; Oskarsson, A.; Ouchida, M.; Ozaki, H.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J.; Park, S.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Perera, G. D. N.; Peresedov, V.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rowan, Z.; Rubin, J. G.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Sako, H.; Samsonov, V.; Sano, M.; Sano, S.; Sarsour, M.; Sato, S.; Sato, T.; Savastio, M.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Sekiguchi, Y.; Semenov, A. Yu.; Semenov, V.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shaver, A.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shim, H. H.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Skutnik, S.; Slunečka, M.; Sodre, T.; Solano, S.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Sparks, N. A.; Staley, F.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Stone, M. R.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Tennant, E.; Themann, H.; Thomas, D.; Thomas, T. L.; Timilsina, A.; Todoroki, T.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Tomášek, M.; Tomita, Y.; Torii, H.; Towell, M.; Towell, R.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Utsunomiya, K.; Vale, C.; Valle, H.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Voas, B.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; Whitaker, S.; White, S. N.; Winter, D.; Wolin, S.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xia, B.; Xie, W.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Yoo, J. S.; Yoon, I.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zelenski, A.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.

2014-12-01

We thank the staff of the Collider-Accelerator and Physics Departments at Brookhaven National Laboratory and the staff of the other PHENIX participating institutions for their vital contributions. We acknowledge support from the Office of Nuclear Physics in the Office of Science of the Department of Energy, the National Science Foundation, a sponsored research grant from Renaissance Technologies LLC, Abilene Christian University Research Council, Research Foundation of SUNY, and Dean of the College of Arts and Sciences, Vanderbilt University (USA), Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (Japan), Conselho Nacional de Desenvolvimento Científico e Tecnológico and Fundação de Amparo à Pesquisa do Estado de São Paulo (Brazil), Natural Science Foundation of China, (People's Republic of China), Ministry of Science, Education, and Sports (Croatia), Ministry of Education, Youth and Sports (Czech Republic), Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique, and Institut National de Physique Nucléaire et de Physique des Particules (France), Bundesministerium für Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany), OTKA NK 101 428 grant and the Ch. Simonyi Fund (Hungary), Department of Atomic Energy and Department of Science and Technology (India), Israel Science Foundation (Israel), National Research Foundation and WCU program of the Ministry Education Science and Technology (Republic of Korea), Physics Department, Lahore University of Management Sciences (Pakistan), Ministry of Education and Science, Russian Academy of Sciences, Federal Agency of Atomic Energy (Russia), VR and Wallenberg Foundation (Sweden), the US Civilian Research and Development Foundation for the Independent States of the Former Soviet Union, and the US-Israel Binational Science Foundation.

PHENIX Collaboration

NASA Astrophysics Data System (ADS)

Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Bataineh, H.; Al-Ta'ani, H.; Alexander, J.; Alfred, M.; Andrews, K. R.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Appelt, E.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bai, X.; Baksay, G.; Baksay, L.; Baldisseri, A.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Barnes, P. D.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belikov, S.; Belmont, R.; Ben-Benjamin, J.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Bing, X.; Black, D.; Blau, D. S.; Boissevain, J. G.; Bok, J.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Broxmeyer, D.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Castera, P.; Chang, B. S.; Chang, W. C.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cole, B. A.; Comets, M. P.; Conesa del Valle, Z.; Connors, M.; Constantin, P.; Cronin, N.; Crossette, N.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; Daugherity, M. S.; David, G.; Dayananda, M. K.; Deaton, M. B.; DeBlasio, K.; Dehmelt, K.; Delagrange, H.; Denisov, A.; d'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Do, J. H.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Gadrat, S.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, H.; Gong, X.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guo, L.; Guragain, H.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Han, S. Y.; Hanks, J.; Harada, H.; Harper, C.; Hartouni, E. P.; Haruna, K.; Hasegawa, S.; Hashimoto, K.; Haslum, E.; Hayano, R.; Hayashi, S.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Hollis, R. S.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hornback, D.; Hoshino, T.; Huang, J.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imazu, Y.; Imrek, J.; Inaba, M.; Inoue, Y.; Iordanova, A.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isinhue, A.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Ivanishchev, D.; Iwanaga, Y.; Jacak, B. V.; Javani, M.; Jeon, S. J.; Jezghani, M.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; John, D.; Johnson, B. M.; Jones, T.; Joo, E.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kanda, S.; Kaneta, M.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kihara, K.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, H.-J.; Kim, H. J.; Kim, K.-B.; Kim, M.; Kim, S. H.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klatsky, J.; Klay, J.; Klein-Boesing, C.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kochenda, L.; Kochetkov, V.; Kofarago, M.; Komatsu, Y.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Krizek, F.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Layton, D.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, G. H.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, S. H.; Lee, S. R.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Leitner, E.; Lenzi, B.; Lewis, B.; Li, X.; Lichtenwalner, P.; Liebing, P.; Lim, S. H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Maai, M.; Malakhov, A.; Malik, M. D.; Manion, A.; Manko, V. I.; Mannel, E.; Mao, Y.; Maruyama, T.; Mašek, L.; Masui, H.; Masumoto, S.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Means, N.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Midori, J.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, A. J.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, D. K.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Miyachi, Y.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Montuenga, P.; Moon, H. J.; Moon, T.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moskowitz, M.; Motschwiller, S.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Nattrass, C.; Nederlof, A.; Netrakanti, P. K.; Newby, J.; Nguyen, M.; Nihashi, M.; Niida, T.; Norman, B. E.; Nouicer, R.; Novak, T.; Novitzky, N.; Nukariya, A.; Nyanin, A. S.; Oakley, C.; Obayashi, H.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Oide, H.; Oka, M.; Okada, K.; Omiwade, O. O.; Onuki, Y.; Orjuela Koop, J. D.; Oskarsson, A.; Ouchida, M.; Ozaki, H.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J.; Park, S.; Park, S. K.; Park, W. J.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Perera, G. D. N.; Peresedov, V.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rowan, Z.; Rubin, J. G.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Sako, H.; Samsonov, V.; Sano, M.; Sano, S.; Sarsour, M.; Sato, S.; Sato, T.; Savastio, M.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Sekiguchi, Y.; Semenov, A. Yu.; Semenov, V.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shaver, A.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shim, H. H.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Skutnik, S.; Slunečka, M.; Sodre, T.; Solano, S.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Sparks, N. A.; Staley, F.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Stone, M. R.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Tennant, E.; Themann, H.; Thomas, D.; Thomas, T. L.; Timilsina, A.; Todoroki, T.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Tomášek, M.; Tomita, Y.; Torii, H.; Towell, M.; Towell, R.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Utsunomiya, K.; Vale, C.; Valle, H.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Voas, B.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; Wessels, J.; Whitaker, S.; White, S. N.; Winter, D.; Wolin, S.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xia, B.; Xie, W.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Yoo, J. S.; Yoon, I.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zelenski, A.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.

2014-11-01

We thank the staff of the Collider-Accelerator and Physics Departments at Brookhaven National Laboratory and the staff of the other PHENIX participating institutions for their vital contributions. We acknowledge support from the Office of Nuclear Physics in the Office of Science of the Department of Energy, the National Science Foundation, a sponsored research grant from Renaissance Technologies LLC, Abilene Christian University Research Council, Research Foundation of SUNY, and Dean of the College of Arts and Sciences, Vanderbilt University (USA), Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (Japan), Conselho Nacional de Desenvolvimento Científico e Tecnológico and Fundaç ao de Amparo à Pesquisa do Estado de São Paulo (Brazil), Natural Science Foundation of China (People's Republic of China), Ministry of Science, Education, and Sports (Croatia), Ministry of Education, Youth and Sports (Czech Republic), Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique, and Institut National de Physique Nucléaire et de Physique des Particules (France), Bundesministerium für Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany), OTKA NK 101 428 grant and the Ch. Simonyi Fund (Hungary), Department of Atomic Energy and Department of Science and Technology (India), Israel Science Foundation (Israel), National Research Foundation and WCU program of the Ministry Education Science and Technology (Korea), Physics Department, Lahore University of Management Sciences (Pakistan), Ministry of Education and Science, Russian Academy of Sciences, Federal Agency of Atomic Energy (Russia), VR and Wallenberg Foundation (Sweden), the US Civilian Research and Development Foundation for the Independent States of the Former Soviet Union, and the US-Israel Binational Science Foundation.

The influence of somatotype on anaerobic performance

PubMed Central

Faulkner, James; Jobson, Simon

2018-01-01

The link between athlete physique and performance in sports is well established. However, a direct link between somatotype three-numeral rating and anaerobic performance has not yet been reported. The purpose of this study was to assess the relations between somatotype and anaerobic performance using both singular and multivariate analyses. Thirty-six physically active males (mean ± standard deviation age 26.0 ± 9.8 years; body mass 79.5 ± 12.9 kg; height 1.82 ± 0.07 m) were somatotype-rated using the Heath-Carter method. Subjects were assessed for 3 repetition maximum (3 RM) bench press and back squat, and completed a 30-second maximal sprint cycle test. Positive correlations were observed between mesomorphy and 3 RM bench press (r = 0.560, p < 0.001), mesomorphy and 3 RM back squat (r = 0.550, p = 0.001) and between mesomorphy and minimum power output (r = 0.357, p = 0.033). Negative correlations were observed between ectomorphy and 3 RM bench press (r = -0.381, p = 0.022), and ectomorphy and 3 RM back squat (r = -0.336, p = 0.045). Individual regression analysis indicated that mesomorphy was the best predictor of 3 RM bench press performance, with 31.4% of variance in 3 RM bench press performance accounted for by the mesomorphy rating (p < 0.001). A combination of mesomorphy and ectomorphy best predicted 3 RM back squat performance (R2 = 0.388, p < 0.04). Around one third of strength performance is predicted by somatotype-assessed physique in physically active males. This could have important implications for the identification of those predisposed to perform well in sports containing strength-based movements and prescription of training programmes. PMID:29787610

The influence of somatotype on anaerobic performance.

PubMed

Ryan-Stewart, Helen; Faulkner, James; Jobson, Simon

2018-01-01

The link between athlete physique and performance in sports is well established. However, a direct link between somatotype three-numeral rating and anaerobic performance has not yet been reported. The purpose of this study was to assess the relations between somatotype and anaerobic performance using both singular and multivariate analyses. Thirty-six physically active males (mean ± standard deviation age 26.0 ± 9.8 years; body mass 79.5 ± 12.9 kg; height 1.82 ± 0.07 m) were somatotype-rated using the Heath-Carter method. Subjects were assessed for 3 repetition maximum (3 RM) bench press and back squat, and completed a 30-second maximal sprint cycle test. Positive correlations were observed between mesomorphy and 3 RM bench press (r = 0.560, p < 0.001), mesomorphy and 3 RM back squat (r = 0.550, p = 0.001) and between mesomorphy and minimum power output (r = 0.357, p = 0.033). Negative correlations were observed between ectomorphy and 3 RM bench press (r = -0.381, p = 0.022), and ectomorphy and 3 RM back squat (r = -0.336, p = 0.045). Individual regression analysis indicated that mesomorphy was the best predictor of 3 RM bench press performance, with 31.4% of variance in 3 RM bench press performance accounted for by the mesomorphy rating (p < 0.001). A combination of mesomorphy and ectomorphy best predicted 3 RM back squat performance (R2 = 0.388, p < 0.04). Around one third of strength performance is predicted by somatotype-assessed physique in physically active males. This could have important implications for the identification of those predisposed to perform well in sports containing strength-based movements and prescription of training programmes.

Relationship of low lean body mass with body weight increase until one year of age and current lifestyles in Japanese young women.

PubMed

Miyamoto, Shoji; Murotani, Kenta; Yanagawa, Takashi; Kato, Atsushi; Matsunaga, Satoshi

2010-06-01

To investigate factors affecting the low lean body mass (LBM) of young women, we focused on the increase in body weight until one year of age and current lifestyles. In 442 young women, the increase in body weight from birth until one year of age, breast-feeding method in infancy, current physique index and body composition, and physique and lifestyles were investigated using a questionnaire. Subjects with an LBM percentile of less than 33.3 (less than 36.8 kg) were classified as having a low LBM (n = 150), and those with a 33.3 or higher LBM percentile as the control (n = 293). Based on body weight changes from birth to days 3 and 7, the subjects were divided into a rapid weight gain group and two non-rapid weight gain groups (groups 1-3). To analyze factors involved in a low LBM, multivariate analysis using a logistic model was employed. The prevalence of a low LBM in the rapid weight gain group was 0.41 times higher than in the others. The prevalence of a low LBM with a low birth weight was 0.58 times higher, indicating that a low birth weight is likely to result in a low LBM. Regarding the lifestyles, the prevalence of a low LBM in subjects with a current breakfasting habit was 0.60 times higher than in those without one. These findings suggest that the thinness of young women characterized by a low LBM is associated with the increase in body weight until one year of age and current lifestyles.

Body image issues in Lithuanian females before and during pregnancy.

PubMed

Tutkuviene, Janina; Juskaite, Austeja; Katinaite, Justina; Silove, Simona; Drasutis, Jonas; Sargautyte, Ruta; Ramasauskaite, Diana; Drasutiene, Grazina

2018-02-01

There is a risk that during pregnancy a woman's changing physique might result in stronger concerns about her appearance and may lead to negative consequences both for mother and foetus. The aim of the present study was to assess women's self-esteem, body image and weight control before and during pregnancy. A cross-sectional study was carried out at the Centre of Obstetrics and Gynaecology of Vilnius University Hospital. In total, 234 pregnant women were investigated. The Self-esteem was measured by Rosenberg's scale (1965), while the attitude towards the body size - by Stunkard's figure rating scale (1983). When rating their actual body size and the preferred body shape using Stunkard's figures, the investigated females chose, on average, 3.40 and 2.93 (respectively) size figures for the period before pregnancy ( p < 0.05), while they picked 4.38 and 3.44 (respectively) figures during pregnancy ( p < 0.05). Women's efforts not to gain weight during pregnancy were not determined by their opinion of their body size during pregnancy ( r s (232) = 0.136, p > 0.05). Regardless of their body shape assessment during pregnancy, pregnant women did not restrict their diet ( r s (232) = 0.064, p > 0.05). Conclusions: during pregnancy women assessed their weight gain adequately, pregnant women chose larger body sizes as an ideal physique if compared to the ones of the period before pregnancy, women's efforts not to gain weight during pregnancy were not determined by their body size perception during pregnancy, pregnant women, despite their body shape assessment during pregnancy, did not restrict their diet, i.e. pregnant women became psychologically adapted to their body changes during pregnancy, and the maternity became a much more important factor than the beauty ideals associated with slender figures.

Body mass prediction from skeletal frame size in elite athletes.

PubMed

Ruff, C B

2000-12-01

Body mass can be estimated from measures of skeletal frame size (stature and bi-iliac (maximum pelvic) breadth) fairly accurately in modern human populations. However, it is not clear whether such a technique will lead to systematic biases in body mass estimation when applied to earlier hominins. Here the stature/bi-iliac method is tested, using data available for modern Olympic and Olympic-caliber athletes, with the rationale that these individuals may be more representative of the general physique and degree of physical conditioning characteristic of earlier populations. The average percent prediction error of body mass among both male and female athletes is less than 3%, with males slightly underestimated and females slightly overestimated. Among males, the ratio of shoulder to hip (biacromial/bi-iliac) breadth is correlated with prediction error, while lower limb/trunk length has only a weak inconsistent effect. In both sexes, athletes in "weight" events (e.g. , shot put, weight-lifting), which emphasize strength, are underestimated, while those in more endurance-related events (e.g., long distance running) are overestimated. It is likely that the environmental pressures facing earlier hominins would have favored more generalized physiques adapted for a combination of strength, speed, agility, and endurance. The events most closely approximating these requirements in Olympic athletes are the decathlon, pentathlon, and wrestling, all of which have average percent prediction errors of body mass of 5% or less. Thus, "morphometric" estimation of body mass from skeletal frame size appears to work reasonably well in both "normal" and highly athletic modern humans, increasing confidence that the technique will also be applicable to earlier hominins. Copyright 2000 Wiley-Liss, Inc.

Alterations in physique among young children after the Great East Japan Earthquake: Results from a nationwide survey.

PubMed

Kikuya, Masahiro; Matsubara, Hiroko; Ishikuro, Mami; Sato, Yuki; Obara, Taku; Metoki, Hirohito; Isojima, Tsuyoshi; Yokoya, Susumu; Kato, Noriko; Tanaka, Toshiaki; Chida, Shoichi; Ono, Atsushi; Hosoya, Mitsuaki; Yokomichi, Hiroshi; Yamagata, Zentaro; Tanaka, Soichiro; Kure, Shigeo; Kuriyama, Shinichi

2017-10-01

Data for earthquake-related alterations in physique among young children in developed countries is lacking. The Great East Japan Earthquake caused severe damage in Iwate, Miyagi, and Fukushima Prefectures in northeastern Japan. We retrospectively obtained anthropometric measurements in nursery school from 40,046 (cohort 1, historical control) and 53,492 (cohort 2) children aged 3.5-4.5 years without overweight in October 2008, and in October 2010, respectively. At the time of the earthquake in March, 2011, children in cohort 1 had already graduated from nursery school; however, children in cohort 2 were still enrolled in nursery school at this time. We compared the onset of overweight at 1 year after the baseline between children enrolled in their school located in one of the three target prefectures versus those in other prefectures using a logistic regression model, with adjustment for sex, age, history of disease, and obesity index at baseline. Overweight was defined as an obesity index of >+15%, which was calculated as (weight minus sex- and height-specific standard weight)/sex- and height-specific standard weight. The odds ratio (OR) for the onset of overweight in the three target prefectures was significant in cohort 2 (OR 1.25; 95% confidence interval [CI], 1.01-1.55) but not in cohort 1. When the two cohort were pooled (n = 93,538), the OR of the interaction term for school location × cohort was significant (OR 1.56; 95% CI, 1.09-2.23). Incident overweight in young children was significantly more common in the three prefectures affected by the Great East Japan Earthquake than in other prefectures after the disaster. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Anthropometric Profiles of Elite Open-Water Swimmers.

PubMed

Shaw, Gregory; Mujika, Iñigo

2018-01-01

Reports detailing the physiques of open-water (OW) swimmers are limited. Data from anthropometric screening around competition provides a unique opportunity to describe the current physical attributes of elite OW swimmers peaking for international competition. Anthropometric screening was undertaken on a group of Australian and French OW swimmers as part of performance monitoring within 2 wk of the 2015 FINA World Championships. Height, mass, and sum of 7 skinfolds were measured using ISAK standardized measurement techniques by 2 trained anthropometrists. Data were collated and compared with previously published data on OW and pool swimmers. French swimmers had lower skinfolds (57.3 ± 6.1 vs 80.5 ± 21.3 mm, P = .0258), were lighter (64.7 ± 10.8 vs 74.6 ± 11.8 kg, P = .013), and had lower lean-mass index (LMI) (34.7 ± 7.3 vs 38.2 ± 8.8, P = .035) than Australian swimmers. Male and female OW swimmers had skinfolds similar to their contemporary OW swimmers but were lower than earlier reports of OW swimmers; however, they were higher than those of pool swimmers. Male and female OW swimmers had 9% and 6% lower LMI, respectively, than pool swimmers. Lower body mass and LMI were correlated with better World Championships finishing positions (R 2  = .46, P = .0151, and R 2  = .45, P = .0177, respectively). These data are a unique report of elite OW swimmers' physiques around international competition and demonstrate a potential morphological optimization in OW swimmers that warrants further investigation in larger populations.

List of Participants

NASA Astrophysics Data System (ADS)

2007-11-01

Mohab Abou ZeidVrije Universiteit, Brussel Joke AdamKatholieke Universiteit Leuven Nikolas AkerblomMax-Planck-Institut für Physik, München Luis Fernando Alday Utrecht University Stelios Alexandris University of Patras Antonio Amariti Università di Milano-Bicocca Nicola Ambrosetti Université de Neuchâtel Pascal Anastasopoulos Università di Roma Tor Vergata Laura Andrianopoli Enrico Fermi Center Carlo Angelantonj Università di Torino Lilia Anguelova Queen Mary, University of London Daniel AreanUniversidade de Santiago de Compostela Gleb ArutyunovUtrecht University Spyros Avramis NTU Athens—University of Patras Ioannis Bakas University of Patras Subrata Bal Dublin Institute for Advanced Studies Igor Bandos Valencia University Jessica Barrett University of Iceland Marco Baumgartl Eidgenössische Technische Hochschule, Zürich Jacopo Bechi Università di Firenze James Bedford Queen Mary, University of London Jorge Bellorin Universidad Autonoma de Madrid Francesco Benini SISSA, Trieste Eric Bergshoeff Centre for Theoretical Physics, University of Groningen Gaetano BertoldiUniversity of Wales, Swansea Adel Bilal Laboratoire de Physique Théorique, École Normale Superieure, Paris Matthias Blau Université de Neuchâtel Johannes BroedelUniversität Hannover Felix Brümmer Universität Heidelberg Julio Cesar Bueno de Andrade São Paulo State University—UNESP Cliff Burgess McMaster University Agostino Butti Laboratoire de Physique Théorique, École Normale Superieure, Paris Marco Caldarelli Universitat de Barcelona Pablo G Camara Centre de Physique Théorique, École Polytechnique, Palaiseau Joan Camps Universitat de Barcelona Felipe Canoura FernandezUniversidade de Santiago de Compostela Luigi Cappiello Università di Napoli Federico II Luca Carlevaro École Polytechnique, Palaiseau Roberto Casero Centre de Physique Théorique, École Polytechnique, Palaiseau Claudio Caviezel Max-Planck-Institut für Physik, München Alessio Celi Universitat de Barcelona Anna Ceresole Istituto Nazionale di Fisica Nucleare and Università di Torino Kang Sin Choi University of Bonn Michele Cirafici University of Patras Andres Collinucci Katholieke Universiteit Leuven Aldo Cotrone Universitat de Barcelona Ben Craps Vrije Universiteit, Brussel Stefano Cremonesi SISSA, Trieste Gianguido Dall'Agata Padova University Sanjit Das Indian Institute of Technology, Kharagpur Forcella Davide SISSA, Trieste Jose A de Azcarraga Valencia University and Instituto de Fìsica Corpuscular (CSIC-UVEG), Valencia Sophie de BuylInstitut des Hautes Études Scientifiques, Bures-sur-Yvette Jean-Pierre Derendinger Université de Neuchâtel Stephane Detournay Università Degli Studi di Milano Paolo Di Vecchia NORDITA, København Oscar Dias Universitat de Barcelona Vladimir Dobrev Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia Joel Ekstrand Department of Theoretical Physics, Uppsala University Federico Elmetti Università di Milano I Diaconu Eugen University of Craiova Oleg Evnin Vrije Universiteit, Brussel Bo Feng Imperial College, London Livia Ferro Università di Torino Pau Figueras Universitat de Barcelona Raphael Flauger University of Texas at Austin Valentina Forini Università di Perugia Angelos Fotopoulos Università di Torino Denis Frank Université de Neuchâtel Lisa Freyhult Albert-Einstein-Institut, Golm Carlos Fuertes Instituto de Física Teórica, Madrid Matthias Gaberdiel Eidgenössische Technische Hochschule, Zürich Maria Pilar Garcia del Moral Università di Torino Daniel Gerber Instituto de Física Teórica, Madrid Valentina Giangreco Marotta Puletti Uppsala University Joaquim Gomis Universitat de Barcelona Gianluca Grignani Università di Perugia Luca Griguolo Università di Parma Umut Gursoy École Polytechnique, Palaiseau and École Normale Supérieure, Paris Michael Haack Ludwig-Maximilians-Universität, München Troels Harmark Niels Bohr Institute, København Alexander Haupt Imperial College, London Michal Heller Jagiellonian University, Krakow Samuli Hemming University of Iceland Yasuaki Hikida DESY, Hamburg Christian Hillmann Max-Planck-Institut für Gravitationsphysik, Potsdam Stephan Hoehne Max-Planck-Institut für Physik, München Gabriele Honecker CERN, Geneva Carlos Hoyos University of Wales, Swansea Mechthild Huebscher Consejo Superior de Investigaciones Cientificas, Madrid Matthias Ihl University of Texas at Austin Emiliano Imeroni University of Wales, Swansea Nikos Irges University of Crete Negru Iulian University of Craiova Matthias Kaminski Ludwig-Maximilians-Universität, München Stefanos Katmadas Universiteit Utrecht Shoichi Kawamoto Oxford University Christoph Keller Eidgenössische Technische Hochschule, Zürich Arjan Keurentjes Vrije Universiteit, Brussel Sadi Khodaee Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran Michael Kiermaier Massachusetts Institute of Technology, Cambridge, MA Elias Kiritsis Centre de Physique Théorique, École Polytechnique, Palaiseau and University of Crete Ingo KirschEidgenössische Technische Hochschule, Zürich Johanna Knapp CERN, Geneva Paul Koerber Max-Planck-Institut für Physik, München Simon Koers Max-Planck-Institut für Physik, München Anatoly Konechny Heriot-Watt University, Edinburgh Peter Koroteev Institute for Theoretical and Experimental Physics (ITEP), Moscow Daniel KreflLudwig-Maximilians-Universität and Max-Planck-Institut für Physik, München Chethan KrishnanUniversité Libre de Bruxelles Stanislav Kuperstein Université Libre de Bruxelles Alberto Lerda Università del Piemonte Orientale, Alessandria Roman Linares Universidad Autonoma Metropolitana, Iztapalapa, México Maria A Lledo Universidad de Valencia Dieter Luest Ludwig-Maximilians-Universität and Max-Planck-Institut für Physik, München Joseph Lykken Fermi National Accelerator Laboratory (Fermilab), Batavia, IL Carlo Maccaferri Vrije Universiteit, Brussel Oscar Macia Universidad de Valencia Tristan Maillard Centre de Physique Théorique, École Polytechnique, Palaiseau Diego Mansi Università Degli Studi di Milano Matteo Marescotti Università del Piemonte Orientale, Alessandria Alberto Mariotti Università di Milano-Bicocca Raffaele Marotta Istituto Nazionale di Fisica Nucleare, Napoli Alessio Marrani Istituto Nazionale di Fisica Nucleare and LNF, Firenze Luca Martucci Instituto de Física Teórica, Madrid and Katholieke Universiteit Leuven David Mateos University of California, Santa Barbara Andrea Mauri Università di Milano Liuba Mazzanti Università di Milano-Bicocca Patrick Meessen Instituto de Física Teórica, Universidad Autónoma de Madrid Lotta Mether Helsinki Institute of Physics Rene Meyer Max-Planck-Institut für Physik, München Giuseppe Milanesi SISSA, Trieste Cesar Miquel-Espanya Universitat de Valencia and Instituto de Física Corpuscular, Valencia Alexander Monin Institute for Theoretical and Experimental Physics (ITEP), Moscow and Moscow State University (MSU) Samuel Monnier Université de Genève Sergio Montero Instituto de Física Teórica, Madrid Nicola Mori Università di Firenze Alexander Marcel Morisse University of California, Santa Cruz Sebastian Moster Max-Planck-Institut für Physik, München Adele Nasti Queen Mary, University of London Vasilis Niarchos École Polytechnique, Palaiseau Emil Nissimov Institute for Nuclear Research and Nuclear Energy, Sofia Francesco Nitti École Polytechnique, Palaiseau Eoin O'Colgain Imperial College, London Niels Obers Niels Bohr Institute, København Rodrigo Olea Università Degli Studi di Milano Marta Orselli Niels Bohr Institute, København Enrico PajerLudwig-Maximilians-Universität, München Eran PaltiOxford University Georgios PapathanasiouBrown University, Providence, RI Angel ParedesCentre de Physique Théorique, École Polytechnique, Palaiseau Jeong-Hyuck ParkMax-Planck-Institut für Physik, München Sara PasquettiUniversità di Parma Silvia PenatiUniversità di Milano-Bicocca Igor PesandoUniversità di Torino Marios PetropoulosÉcole Polytechnique, Palaiseau Roberto PettorinoUniversità di Napoli Federico II Franco PezzellaIstituto Nazionale di Fisica Nucleare, Napoli Moises Picon PonceIstituto Nazionale di Fisica Nucleare, Padova Marco PirroneUniversità di Milano-Bicocca Erik PlauschinnMax-Planck-Institut für Physik, München Andre PloeghCentre for Theoretical Physics, University of Groningen Giuseppe PolicastroLaboratoire de Physique Théorique, École Normale Superieure, Paris Josep PonsUniversitat de Barcelona S Prem KumarUniversity of Wales, Swansea Nikolaos PrezasCERN, Geneva Carlo Alberto RattiUniversità di Milano-Bicocca Riccardo RicciImperial College, London Alejandro RiveroEscuela Universitaria Politécnica de Teruel, Universidad de Zaragoza Irene RodriguezInstituto de Física Teórica, Madrid Maria Jose RodriguezUniversitat de Barcelona Diederik RoestUniversitat de Barcelona Alberto RomagnoniLaboratoire de Physique Théorique d'Orsay, Paris Christian RomelsbergerDublin Institute for Advanced Studies Jan RosseelKatholieke Universiteit Leuven Sebastiano RossiEidgenössische Technische Hochschule, Zürich Felix RustMax-Planck-Institut für Physik, München Cheol RyouPohang University of Science and Technology (POSTECH) Christian SaemannDublin Institute for Advanced Studies Houman Safaai SISSA, Trieste Alberto SantambrogioIstituto Nazionale di Fisica Nucleare, Sezione di Milano Frank SaueressigUniversiteit Utrecht Ricardo SchiappaCERN, Geneva Cornelius Schmidt-ColinetEidgenössische Technische Hochschule, Zürich Maximilian Schmidt-SommerfeldMax-Planck-Institut für Physik, München Waldemar SchulginMax-Planck-Institut für Physik, München Claudio ScruccaUniversité de Neuchâtel Nathan SeibergInstitute of Advanced Studies, Princeton, NJ Domenico SeminaraUniversità di Firenze Alexander SevrinVrije Universiteit, Brussel Konstadinos SfetsosUniversity of Patras Kostas SiamposUniversity of Patras Christoph SiegUniversità Degli Studi di Milano Vaula Silvia Instituto de Física Teórica, Madrid Aaron Sim Imperial College, London Woojoo Sim Pohang University of Science and Technology (POSTECH) Sergey Slizovskiy Department of Theoretical Physics, Uppsala University Paul Smyth Katholieke Universiteit Leuven Corneliu Sochichiu Laboratori Nazionali di Frascati Dmitri Sorokin Istituto Nazionale di Fisica Nucleare, Padova Kellogg Stelle Imperial College, London Piotr Surowka Jagiellonian University, Krakow Yasutoshi Takayama Niels Bohr Institute, København Laura Tamassia Katholieke Universiteit Leuven Radu Tatar University of Liverpool Larus Thorlacius University of Iceland Paavo Tiitola Helsinki Institute of Physics Diego Trancanelli Stony Brook University, NY Michele TraplettiInstitut für Theoretische Physik, Universität Heidelberg Mario Trigiante Politecnico di Torino Angel Uranga CERN, Geneva and Instituto de Física Teórica, Madrid Roberto Valandro SISSA, Trieste Dieter Van den Bleeken Katholieke Universiteit Leuven Antoine Van Proeyen Katholieke Universiteit Leuven Thomas Van Riet Centre for Theoretical Physics, University of Groningen Pierre Vanhove Service de Physique Théorique, Saclay Oscar Varela Universidad de Valencia Alessandro Vichi Scuola Normale Superiore di Pisa Massimiliano VinconQueen Mary, University of London John Ward Queen Mary, University of London and CERN, Geneva Brian Wecht Massachusetts Institute of Technology, Cambridge, MA Marlene Weiss Eidgenössische Technische Hochschule, Zürich and CERN, Geneva Sebastian Weiss Université de Neuchâtel Alexander Wijns Vrije Universiteit, Brussel Przemek Witaszczyk Jagiellonian University, Krakow Timm Wrase University of Texas at Austin Jun-Bao Wu SISSA, Trieste Amos Yarom Ludwig-Maximilians-Universität, München Marco Zagermann Max-Planck-Institut für Physik, München Daniela Zanon Dipartimento di Fisica, Università di Milano Andrea Zanzi University of Bonn Andrey Zayakin Moscow State University (MSU) and Institute for Theoretical and Experimental Physics (ITEP), Moscow Konstantinos Zoubos Queen Mary, University of London

Anisotropy and Microstructure of High Coercivity Rare Earth Iron Permanent Magnets, List of Papers Published

DTIC Science & Technology

1989-01-01

EARTH IRON PERMANENT MAGNETS. LIST OF PAPERS PUBLISHED 1986 - 1989 Contract No.: DAJA45-86-C-0010 Report No.: R/D-5295-MS-01 NOV 0 � A = LIST OF...R.Gr~ssinger - ’-Does a Co substitution really improve the temperature dependence of Nd-Fe-B based permanent magnets" .’ Proc. of 91h Int. Workshop...in NdzFe,4-4-iZx B (Z=A1,Si,Co, Ga) compounds", J. de Physique 49 (1988) CS-599. (16) R.Gr8ssinger, R.Krewenka, H.Buchn~r, H.Harada " A new analysis of

Étude statistique et dynamique de la propagation d'épidémies dans un réseau de petit mondeStatistical and dynamical study of the epidemics propagation in a small world network

NASA Astrophysics Data System (ADS)

Zekri, Nouredine; Clerc, Jean Pierre

We study numerically in this work the statistical and dynamical properties of the clusters in a one dimensional small world model. The parameters chosen correspond to a realistic network of children of school age where a disease like measles can propagate. Extensive results on the statistical behavior of the clusters around the percolation threshold, as well as the evoltion with time, are discussed. To cite this article: N. Zekri, J.P. Clerc, C. R. Physique 3 (2002) 741-747.

"Does understanding the brain need proteomics and does understanding proteomics need brains?"--Second HUPO HBPP Workshop hosted in Paris.

PubMed

Hamacher, Michael; Klose, Joachim; Rossier, Jean; Marcus, Katrin; Meyer, Helmut E

2004-07-01

The second Human Brain Proteome Project (HBPP) Workshop of the Human Proteome Organisation (HUPO) took place at the Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI) from April 23-24, 2004. During two days, more than 70 attendees from Europe, Asia and the US came together to decide basic strategic approaches, standards and the beginning of a pilot phase prior to further studies of the human brain proteome. The international consortium presented the technological and scientific portfolio and scheduled the time table for the next year.

[Comparison of cardiopulmonary endurance and muscular fitness in teenagers between Hong Kong and inland cities].

PubMed

Hong, Y; Chan, K; Wang, Y

1997-01-01

A study on the data of the physique investigated in teenagers was carried out between Hong Kong and inland cities to compare their cardiopulmonary endurance and muscular fitness. Results revealed that cardiopulmonary endurance in school teenagers of both sex at different ages in inland cities was better than that in Hong Kong. Muscular strength and endurance of sports performance of teenagers, except for standing long jump, in Hong Kong were weaker than that in inland cities. It suggests that attention should be paid to the involvement of teenagers in physical education with the increase of people's living standard.

Beginning inflation in an inhomogeneous universe

DOE Office of Scientific and Technical Information (OSTI.GOV)

East, William E.; Kleban, Matthew; Linde, Andrei

Using numerical solutions of the full Einstein field equations coupled to a scalar inflaton field in 3+1 dimensions, we study the conditions under which a universe that is initially expanding, highly inhomogeneous and dominated by gradient energy can transition to an inflationary period. If the initial scalar field variations are contained within a sufficiently flat region of the inflaton potential, and the universe is spatially flat or open on average, inflation will occur following the dilution of the gradient and kinetic energy due to expansion. This is the case even when the scale of the inhomogeneities is comparable to themore » initial Hubble length, and overdense regions collapse and form black holes, because underdense regions continue expanding, allowing inflation to eventually begin. In conclusion, this establishes that inflation can arise from highly inhomogeneous initial conditions and solve the horizon and flatness problems, at least as long as the variations in the scalar field do not include values that exceed the inflationary plateau.« less

Beginning inflation in an inhomogeneous universe

DOE PAGES

East, William E.; Kleban, Matthew; Linde, Andrei; ...

2016-09-06

Using numerical solutions of the full Einstein field equations coupled to a scalar inflaton field in 3+1 dimensions, we study the conditions under which a universe that is initially expanding, highly inhomogeneous and dominated by gradient energy can transition to an inflationary period. If the initial scalar field variations are contained within a sufficiently flat region of the inflaton potential, and the universe is spatially flat or open on average, inflation will occur following the dilution of the gradient and kinetic energy due to expansion. This is the case even when the scale of the inhomogeneities is comparable to themore » initial Hubble length, and overdense regions collapse and form black holes, because underdense regions continue expanding, allowing inflation to eventually begin. In conclusion, this establishes that inflation can arise from highly inhomogeneous initial conditions and solve the horizon and flatness problems, at least as long as the variations in the scalar field do not include values that exceed the inflationary plateau.« less

Beginning inflation in an inhomogeneous universe

DOE Office of Scientific and Technical Information (OSTI.GOV)

East, William E.; Kleban, Matthew; Linde, Andrei

Using numerical solutions of the full Einstein field equations coupled to a scalar inflaton field in 3+1 dimensions, we study the conditions under which a universe that is initially expanding, highly inhomogeneous and dominated by gradient energy can transition to an inflationary period. If the initial scalar field variations are contained within a sufficiently flat region of the inflaton potential, and the universe is spatially flat or open on average, inflation will occur following the dilution of the gradient and kinetic energy due to expansion. This is the case even when the scale of the inhomogeneities is comparable to themore » initial Hubble length, and overdense regions collapse and form black holes, because underdense regions continue expanding, allowing inflation to eventually begin. This establishes that inflation can arise from highly inhomogeneous initial conditions and solve the horizon and flatness problems, at least as long as the variations in the scalar field do not include values that exceed the inflationary plateau.« less

Galaxy evolution in extreme environments: Molecular gas content star formation and AGN in isolated void galaxies

NASA Astrophysics Data System (ADS)

Das, Mousumi; Iono, Daisuke; Saito, Toshiki; Subramanian, Smitha

Since the early redshift surveys of the large scale structure of our universe, it has become clear that galaxies cluster along walls, sheet and filaments leaving large, empty regions called voids between them. Although voids represent the most under dense parts of our universe, they do contain a sparse but significant population of isolated galaxies that are generally low luminosity, late type disk galaxies. Recent studies show that most void galaxies have ongoing star formation and are in an early stage of evolution. We present radio, optical studies of the molecular gas content and star formation in a sample of void galaxies. Using SDSS data, we find that AGN are rare in these systems and are found only in the Bootes void; their black hole masses and radio properties are similar to bright spirals galaxies. Our studies suggest that close galaxy interactions and gas accretion are the main drivers of galaxy evolution in these systems despite their location in the underdense environment of the voids.

The f ( R ) halo mass function in the cosmic web

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun-Bates, F. von; Winther, H.A.; Alonso, D.

An important indicator of modified gravity is the effect of the local environment on halo properties. This paper examines the influence of the local tidal structure on the halo mass function, the halo orientation, spin and the concentration-mass relation. We use the excursion set formalism to produce a halo mass function conditional on large-scale structure. Our simple model agrees well with simulations on large scales at which the density field is linear or weakly non-linear. Beyond this, our principal result is that f ( R ) does affect halo abundances, the halo spin parameter and the concentration-mass relationship in anmore » environment-independent way, whereas we find no appreciable deviation from \\text(ΛCDM) for the mass function with fixed environment density, nor the alignment of the orientation and spin vectors of the halo to the eigenvectors of the local cosmic web. There is a general trend for greater deviation from \\text(ΛCDM) in underdense environments and for high-mass haloes, as expected from chameleon screening.« less

Lensing in the geodesic light-cone coordinates and its (exact) illustration to an off-center observer in Lemaȋtre-Tolman-Bondi models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fanizza, G.; Nugier, F., E-mail: giuseppe.fanizza@ba.infn.it, E-mail: fabienjean.nugier@unibo.it

We present in this paper a new application of the geodesic light-cone (GLC) gauge for weak lensing calculations. Using interesting properties of this gauge, we derive an exact expression of the amplification matrix—involving convergence, magnification and shear—and of the deformation matrix—involving the optical scalars. These expressions are simple and non-perturbative as long as no caustics are created on the past light-cone and are, by construction, free from the thin lens approximation. We apply these general expressions on the example of an Lemaȋtre-Tolman-Bondi (LTB) model with an off-center observer and obtain explicit forms for the lensing quantities as a direct consequencemore » of the non-perturbative transformation between GLC and LTB coordinates. We show their evolution in redshift after a numerical integration, for underdense and overdense LTB models, and interpret their respective variations in the simple non-curvature case.« less

Modeling the Shock Hugoniot in Porous Materials

NASA Astrophysics Data System (ADS)

Cochrane, Kyle R.; Shulenburger, Luke; Mattsson, Thomas R.; Lane, J. Matthew D.; Weck, Philippe F.; Vogler, Tracy J.; Desjarlais, Michael P.

2017-06-01

Porous materials are present in many scenarios from planetary science to ICF. Understanding how porosity modifies the behavior of the shock Hugoniot in an equation of state is key to being able to predictively simulate experiments. For example, modeling shocks in under-dense iron oxide can aid in understanding planetary formation and silica aerogel can be used to approximate the shock response of deuterium. Simulating the shock response of porous materials presents a variety of theoretical challenges, but by combining ab initio calculations with a surface energy and porosity model, we are able to accurately represent the shock Hugoniot. Finally, we show that this new approach can be used to calculate the Hugoniot of porous materials using existing tabular equations of state. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Radar observations of the Geminid meteoroid stream

NASA Astrophysics Data System (ADS)

Cevolani, G.; Bortolotti, G.; Foschini, L.; Franceschi, C.; Grassi, G.; Trivellone, G.

1994-08-01

Continuous radio-wave monitoring of the Geminid activity in December 1992 and 1993 by using a forward-scatter (FS) bistatic radar over the Bologna-Lecce baseline (700 km) in Italy, reveals peculiar structural aspects of the stream in terms of signal amplitude-rate and duration-rate dependence. The observational results of the Geminid display obtained in the two consecutive years with differentiated peak levels of transmitted power, exhibit different time distributions of underdense meteors against the signal received power. Both sets of data relative to the peak activity in December 12-14, show reflection properties of Geminids which are atypical if compared with echoes from cometary-type showers, with really high echo counts at mid-upper levels of the peak received power. A comparison with the records of 1986 Geminids at the Budrio backscatter radar station near Bologna, shows an asymmetric curve of activity, with smaller particles shifted to shorter and less eccentric orbits, the peak flux occurring earlier than that of larger ones.

A study of the formation and dynamics of galaxies

NASA Astrophysics Data System (ADS)

Fillmore, J. A.

The first half of this thesis is a study on the growth of perturbations in the early universe which might lead to galaxies, clusters of galaxies, or regions void of galaxies. The growth of self-similar perturbations in an Einstein-deSitter universe with cold, collisionless particles is investigated. Three classes of solutions are obtained; one each with planar, cylindrical, and spherical symmetry. The solutions follow the development of structure in both the linear and nonlinear regimes. Self-similar spherical voids which develop from initially underdense regions are also investigated. The character of each solution depends upon the initial density deficit. The second half of this thesis details solutions of steady-state axisymmetric models of elliptical and disk galaxies, and considers which observable properties can be used as diagnostics of the kinematic configuration of the spheroidal component of these systems. Two component mass models are fitted to surface brightness measurements and used to fit kinematic models to the velocity data.

Facteurs prédictifs de succès des étudiants en première année de médecine à l'université de Parakou

PubMed Central

Adoukonou, Thierry; Tognon-Tchegnonsi, Francis; Mensah, Emile; Allodé, Alexandre; Adovoekpe, Jean-Marie; Gandaho, Prosper; Akpona, Simon

2016-01-01

Introduction Plusieurs facteurs dont les notes obtenues au BAC peuvent influencer les performances académiques des étudiants en première année de médecine. L'objectif de cette étude était d’évaluer la relation entre les résultats des étudiants au BAC et le succès en première année de médecine. Méthodes Nous avons réalisé une étude analytique ayant inclus l'ensemble des étudiants régulièrement inscrits en première année à la Faculté de Médecine de l'université de Parakou durant l'année académique 2010-2011. Les données concernant les notes par discipline et mention obtenue au BAC ont été collectées. Une analyse multivariée utilisant la régression logistique et la régression linéaire multiple a permis d’établir les meilleurs prédicteurs du succès et de la moyenne de l’étudiant en fin d'année. Le logiciel SPSS version 17.0 a été utilisé pour l'analyse des données et un p<0,05 a été considéré comme statistiquement significatif. Résultats Parmi les 414 étudiants régulièrement inscrits les données de 407 ont pu être exploitées. Ils étaient âgés de 15 à 31 ans; 262 (64,4%) étaient de sexe masculin. 98 étaient admis avec un taux de succès de 23,7%. Le sexe masculin, la note obtenue en mathématiques, en sciences physiques, la moyenne au BAC et la mention étaient associés au succès en fin d'année mais en analyse multivariée seule une note en sciences physiques > 15/20 était associée au succès (OR: 2,8 [1,32- 6,00]). Pour la moyenne générale obtenue en fin d'année seule une mention bien obtenue au BAC était associée (coefficient de l'erreur standard: 0,130 Bêta =0,370 et p=0,00001). Conclusion Les meilleurs prédicateurs du succès en première année étaient une bonne moyenne en sciences physiques au BAC et une mention bien. La prise en compte de ces éléments dans le recrutement des étudiants en première année pourrait améliorer les résultats académiques. PMID:27313819

Tutankhamun and his brothers. Familial gynecomastia in the Eighteenth Dynasty.

PubMed

Paulshock, B Z

1980-07-11

Many images of the last four hereditary pharaohs of the Eighteenth Egyptian Dynasty (1559 BC to 1319 BC), Amenophis III, Amenophis IV (also known as Akhenaten), Smenkhkare, and Tutankhamun, show them with gynecomastia. Amenophis III was most probably the sire of the last three. The feminine physique and other abnormalities of Amenophis IV have been extensively commented on as indicative of some sort of pathological condition, but the gynecomastia of the others, including Tutankhamun, has been glossed over or considered an artistic mannerism of the El Amarna period. An alternative theory, that the gynecomastia was actually representational and indicative of a familial abnormality in two or three generations, is suggested.

Un regard international sur la sécurité nucléaire

NASA Astrophysics Data System (ADS)

Birkhofer, Adolf

2002-10-01

Safety has always been an important objective in nuclear technology. Starting with a set of sound physical principles and prudent design approaches, safety concepts have gradually been refined and cover now a wide range of provisions related to design, quality and operation. Research, the evaluation of operating experiences and probabilistic risk assessments constitute an essential basis and international co-operation plays a significant role in that context. Concerning future developments a major objective for new reactor concepts, such as the EPR, is to practically exclude a severe core damage accident with large scale consequences outside the plant. To cite this article: A. Birkhofer, C. R. Physique 3 (2002) 1059-1065.

Modélisation des charges d'espace dans les isolants solides par une analyse spectrale

NASA Astrophysics Data System (ADS)

Haas, V.; Scouarnec, Ch.; Franceschi, J. L.

1998-01-01

A mathematical method based on spectral algebra is developped for the thermal modulation method. These methods permit to measure the space charge distribution in solid insulators. The modelling presented permits to evaluate the performances and the limitations of the measurement method. Une linéarisation par l'algèbre spectrale a été développée dans une méthode de modulation thermique pour mesurer la distribution des charges électriques dans les isolants solides. La modélisation présentée permet d'évaluer les performances et les limites tant numériques que physiques de la méthode de mesure.

Observations of chromospheric lines from OSO-8

NASA Technical Reports Server (NTRS)

Grossmann-Doerth, U.; Kneer, F.; Uexkuell, M.; Artzner, G. E.; Vial, J. C.

1980-01-01

Results of OSO-8 measurements of the line profiles of the solar Lyman alpha, Ca II K and Mg II k lines are presented. Observations were obtained with the Laboratoire de Physique Stellaire et Planetaire spectrometer at spectral resolutions of 0.25 and 0.060 A for Lyman alpha and 0.025 A for the Mg II and Ca II lines. The Lyman alpha profiles are found to be highly variable according to spatial position with the intensities of the three lines well correlated, and confirm previous observations of the quiet solar chromosphere. Data suggest that the quiet chromosphere is a dynamical phenomenon whose description in terms of a static model atmosphere is only qualitatively valid at best.

A UNIX SVR4-OS 9 distributed data acquisition for high energy physics

NASA Astrophysics Data System (ADS)

Drouhin, F.; Schwaller, B.; Fontaine, J. C.; Charles, F.; Pallares, A.; Huss, D.

1998-08-01

The distributed data acquisition (DAQ) system developed by the GRPHE (Groupe de Recherche en Physique des Hautes Energies) group is a combination of hardware and software dedicated to high energy physics. The system described here is used in the beam tests of the CMS tracker. The central processor of the system is a RISC CPU hosted in a VME card, running a POSIX compliant UNIX system. Specialized real-time OS9 VME cards perform the instrumentation control. The main data flow goes over a deterministic high speed network. The UNIX system manages a list of OS9 front-end systems with a synchronisation protocol running over a TCP/IP layer.

Atmospheric and meteorological Lidar: from pioneers to space applications

NASA Astrophysics Data System (ADS)

Flamant, Pierre H.

2005-10-01

The 'Light Detection and Ranging' technique, or Lidar, is a laser application to remote sensing. Lidar was in the laboratory stage in the 1960s and in less than 40 years it became a serious candidate for space applications at the turn of the 21st century. Over the years, the Lidar community made significant contributions to Lidar sciences and advancing the technique that makes Lidar an inevitable partner in geophysics and Earth observation. The French community, especially the Service d'Aéronomie and Laboratoire de Météorologie Dynamique, have been involved since the beginning in the Lidar venture and made significant contribution. To cite this article: P.H. Flamant, C. R. Physique 6 (2005).

Body-part compatibility effects are modulated by the tendency for women to experience negative social comparative emotions and the body-type of the model.

PubMed

Pila, Eva; Jovanov, Kimberely; Welsh, Timothy N; Sabiston, Catherine M

2017-01-01

Although exposure to physique-salient media images of women's bodies has been consistently linked with negative psychological consequences, little is known about the cognitive processes that lead to these negative effects. The present study employed a novel adaptation of a computerized response time (RT) task to (i) assess implicit cognitive processing when exposed to the body of another individual, and (ii) examine individual differences in social comparative emotions that may influence the cognitive processing of human bodies. Adult females with low (n = 44) or high (n = 23) tendencies for comparative emotions completed a task in which they executed responses to coloured targets presented on the hands or feet of images of ultra-thin, average-size, and above average-size female models. Although the colour of the target is the only relevant target feature, it is typically found that the to-be-ignored location of the target on the body of the model influences RTs such that RTs are shorter when the target is on a body-part that is compatible with the responding limb (e.g., hand response when target was on hand) than on a body-part that is incompatible with the responding limb (e.g., hand response when target was on foot). Findings from the present study revealed that the magnitude of the body-part compatibility effect (i.e., the index of the cognitive processing of the model) was modulated by tendencies for affective body-related comparisons. Specifically, women who were prone to experiencing social comparative emotions demonstrated stronger and more consistent body-part compatibility effects across models. Therefore, women with higher social comparison tendencies have heightened processing of bodies at a neurocognitive level and may be at higher risk of the negative outcomes linked with physique-salient media exposure.

Methodes d'amas quantiques a temperature finie appliquees au modele de Hubbard

NASA Astrophysics Data System (ADS)

Plouffe, Dany

Depuis leur decouverte dans les annees 80, les supraconducteurs a haute temperature critique ont suscite beaucoup d'interet en physique du solide. Comprendre l'origine des phases observees dans ces materiaux, telle la supraconductivite, est l'un des grands defis de la physique theorique du solide des 25 dernieres annees. L'un des mecanismes pressentis pour expliquer ces phenomenes est la forte interaction electron-electron. Le modele de Hubbard est l'un des modeles les plus simples pour tenir compte de ces interactions. Malgre la simplicite apparente de ce modele, certaines de ses caracteristiques, dont son diagramme de phase, ne sont toujours pas bien etablies, et ce malgre plusieurs avancements theoriques dans les dernieres annees. Cette etude se consacre a faire une analyse de methodes numeriques permettant de calculer diverses proprietes du modele de Hubbard en fonction de la temperature. Nous decrivons des methodes (la VCA et la CPT) qui permettent de calculer approximativement la fonction de Green a temperature finie sur un systeme infini a partir de la fonction de Green calculee sur un amas de taille finie. Pour calculer ces fonctions de Green, nous allons utiliser des methodes permettant de reduire considerablement les efforts numeriques necessaires pour les calculs des moyennes thermodynamiques, en reduisant considerablement l'espace des etats a considerer dans ces moyennes. Bien que cette etude vise d'abord a developper des methodes d'amas pour resoudre le modele de Hubbard a temperature finie de facon generale ainsi qu'a etudier les proprietes de base de ce modele, nous allons l'appliquer a des conditions qui s'approchent de supraconducteurs a haute temperature critique. Les methodes presentees dans cette etude permettent de tracer un diagramme de phase pour l'antiferromagnetisme et la supraconductivite qui presentent plusieurs similarites avec celui des supraconducteurs a haute temperature. Mots-cles : modele de Hubbard, thermodynamique, antiferromagnetisme, supraconductivite, methodes numeriques, larges matrices

Body-part compatibility effects are modulated by the tendency for women to experience negative social comparative emotions and the body-type of the model

PubMed Central

Jovanov, Kimberely; Welsh, Timothy N.; Sabiston, Catherine M.

2017-01-01

Although exposure to physique-salient media images of women’s bodies has been consistently linked with negative psychological consequences, little is known about the cognitive processes that lead to these negative effects. The present study employed a novel adaptation of a computerized response time (RT) task to (i) assess implicit cognitive processing when exposed to the body of another individual, and (ii) examine individual differences in social comparative emotions that may influence the cognitive processing of human bodies. Adult females with low (n = 44) or high (n = 23) tendencies for comparative emotions completed a task in which they executed responses to coloured targets presented on the hands or feet of images of ultra-thin, average-size, and above average-size female models. Although the colour of the target is the only relevant target feature, it is typically found that the to-be-ignored location of the target on the body of the model influences RTs such that RTs are shorter when the target is on a body-part that is compatible with the responding limb (e.g., hand response when target was on hand) than on a body-part that is incompatible with the responding limb (e.g., hand response when target was on foot). Findings from the present study revealed that the magnitude of the body-part compatibility effect (i.e., the index of the cognitive processing of the model) was modulated by tendencies for affective body-related comparisons. Specifically, women who were prone to experiencing social comparative emotions demonstrated stronger and more consistent body-part compatibility effects across models. Therefore, women with higher social comparison tendencies have heightened processing of bodies at a neurocognitive level and may be at higher risk of the negative outcomes linked with physique-salient media exposure. PMID:28632746

Nanoscale density variations induced by high energy heavy ions in amorphous silicon nitride and silicon dioxide

NASA Astrophysics Data System (ADS)

Mota-Santiago, P.; Vazquez, H.; Bierschenk, T.; Kremer, F.; Nadzri, A.; Schauries, D.; Djurabekova, F.; Nordlund, K.; Trautmann, C.; Mudie, S.; Ridgway, M. C.; Kluth, P.

2018-04-01

The cylindrical nanoscale density variations resulting from the interaction of 185 MeV and 2.2 GeV Au ions with 1.0 μm thick amorphous SiN x :H and SiO x :H layers are determined using small angle x-ray scattering measurements. The resulting density profiles resembles an under-dense core surrounded by an over-dense shell with a smooth transition between the two regions, consistent with molecular-dynamics simulations. For amorphous SiN x :H, the density variations show a radius of 4.2 nm with a relative density change three times larger than the value determined for amorphous SiO x :H, with a radius of 5.5 nm. Complementary infrared spectroscopy measurements exhibit a damage cross-section comparable to the core dimensions. The morphology of the density variations results from freezing in the local viscous flow arising from the non-uniform temperature profile in the radial direction of the ion path. The concomitant drop in viscosity mediated by the thermal conductivity appears to be the main driving force rather than the presence of a density anomaly.

Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators

NASA Astrophysics Data System (ADS)

Fonseca, R. A.; Vieira, J.; Fiuza, F.; Davidson, A.; Tsung, F. S.; Mori, W. B.; Silva, L. O.

2013-12-01

A new generation of laser wakefield accelerators (LWFA), supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modelling to further understand the underlying physics and identify optimal regimes, but large scale modelling of these scenarios is computationally heavy and requires the efficient use of state-of-the-art petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed/shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modelling of LWFA, demonstrating speedups of over 1 order of magnitude on the same hardware. Finally, scalability to over ˜106 cores and sustained performance over ˜2 P Flops is demonstrated, opening the way for large scale modelling of LWFA scenarios.

Morphological statistics of the cosmic web

NASA Astrophysics Data System (ADS)

Shandarin, Sergei F.

2004-07-01

We report the first systematic study of the supercluster-void network in the ΛCDM concordance cosmology treating voids and superclusters on an equal footing. We study the dark matter density field in real space smoothed with the Ls = 5 h[minus sign]1Mpc Gaussian window. Superclusters and voids are defined as individual members of over-dense and under-dense excursion sets respectively. We determine the morphological properties of the cosmic web at a large number of dark matter density levels by computing Minkowski functionals for every supercluster and void. At the adopted smoothing scale individual superclusters totally occupy no more than about 5% of the total volume and contain no more than 20% of mass if the largest supercluster is excluded. Likewise, individual voids totally occupy no more than 14% of volume and contain no more than 4% of mass if the largest void is excluded. The genus of individual superclusters can be ˜ 5 while the genus of individual voids reaches ˜ 55, implying significant amount of substructure in superclusters and especially in voids. Large voids are typically distinctly non-spherical.

H0LiCOW VIII. A weak-lensing measurement of the external convergence in the field of the lensed quasar HE 0435-1223

NASA Astrophysics Data System (ADS)

Tihhonova, O.; Courbin, F.; Harvey, D.; Hilbert, S.; Rusu, C. E.; Fassnacht, C. D.; Bonvin, V.; Marshall, P. J.; Meylan, G.; Sluse, D.; Suyu, S. H.; Treu, T.; Wong, K. C.

2018-07-01

We present a weak gravitational lensing measurement of the external convergence along the line of sight to the quadruply lensed quasar HE 0435-1223. Using deep r-band images from Subaru Suprime Cam, we observe galaxies down to a 3σ limiting magnitude of ˜26 mag resulting in a source galaxy density of 14 galaxies per square arcminute after redshift-based cuts. Using an inpainting technique and multiscale entropy filtering algorithm, we find that the region in close proximity to the lens has an estimated external convergence of κ =-0.012^{+0.020}_{-0.013} and is hence marginally underdense. We also rule out the presence of any halo with a mass greater than Mvir = 1.6 × 1014h-1M⊙ (68 per cent confidence limit). Our results, consistent with previous studies of this lens, confirm that the intervening mass along the line of sight to HE 0435-1223 does not affect significantly the cosmological results inferred from the time-delay measurements of that specific object.

Massive Galaxies Are Larger in Dense Environments: Environmental Dependence of Mass-Size Relation of Early-type Galaxies

NASA Astrophysics Data System (ADS)

Yoon, Yongmin; Im, Myungshin; Kim, Jae-Woo

2017-01-01

Under the Λ cold dark matter (ΛCDM) cosmological models, massive galaxies are expected to be larger in denser environments through frequent hierarchical mergers with other galaxies. Yet, observational studies of low-redshift early-type galaxies have shown no such trend, standing as a puzzle to solve during the past decade. We analyzed 73,116 early-type galaxies at 0.1 ≤ z < 0.15, adopting a robust nonparametric size measurement technique and extending the analysis to many massive galaxies. We find for the first time that local early-type galaxies heavier than 1011.2 M⊙ show a clear environmental dependence in mass-size relation, in such a way that galaxies are as much as 20%-40% larger in the densest environments than in underdense environments. Splitting the sample into the brightest cluster galaxies (BCGs) and non-BCGs does not affect the result. This result agrees with the ΛCDM cosmological simulations and suggests that mergers played a significant role in the growth of massive galaxies in dense environments as expected in theory.

Inverted initial conditions: Exploring the growth of cosmic structure and voids

DOE PAGES

Pontzen, Andrew; Roth, Nina; Peiris, Hiranya V.; ...

2016-05-18

We introduce and explore “paired” cosmological simulations. A pair consists of an A and B simulation with initial conditions related by the inversion δ A(x,t initial) = –δ B(x,t initial) (underdensities substituted for overdensities and vice versa). We argue that the technique is valuable for improving our understanding of cosmic structure formation. The A and B fields are by definition equally likely draws from ΛCDM initial conditions, and in the linear regime evolve identically up to the overall sign. As nonlinear evolution takes hold, a region that collapses to form a halo in simulation A will tend to expand tomore » create a void in simulation B. Applications include (i) contrasting the growth of A-halos and B-voids to test excursion-set theories of structure formation, (ii) cross-correlating the density field of the A and B universes as a novel test for perturbation theory, and (iii) canceling error terms by averaging power spectra between the two boxes. Furthermore, generalizations of the method to more elaborate field transformations are suggested.« less

EBL Inhomogeneity and Hard-Spectrum Gamma-Ray Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdalla, Hassan; Böttcher, Markus

2017-02-01

The unexpectedly hard very-high-energy (VHE; E > 100 GeV) γ -ray spectra of a few distant blazars have been interpreted as evidence of a reduction of the γγ opacity of the universe due to the interaction of VHE γ -rays with the extragalactic background light (EBL) compared to the expectation from current knowledge of the density and cosmological evolution of the EBL. One of the suggested solutions to this problem involves the inhomogeneity of the EBL. In this paper, we study the effects of such inhomogeneity on the energy density of the EBL (which then also becomes anisotropic) and themore » resulting γγ opacity. Specifically, we investigate the effects of cosmic voids along the line of sight to a distant blazar. We find that the effect of such voids on the γγ opacity, for any realistic void size, is only of the order of ≲1% and much smaller than expected from a simple linear scaling of the γγ opacity with the line-of-sight galaxy underdensity due to a cosmic void.« less

H0LiCOW VIII. A weak lensing measurement of the external convergence in the field of the lensed quasar HE 0435-1223

NASA Astrophysics Data System (ADS)

Tihhonova, O.; Courbin, F.; Harvey, D.; Hilbert, S.; Rusu, C. E.; Fassnacht, C. D.; Bonvin, V.; Marshall, P. J.; Meylan, G.; Sluse, D.; Suyu, S. H.; Treu, T.; Wong, K. C.

2018-04-01

We present a weak gravitational lensing measurement of the external convergence along the line of sight to the quadruply lensed quasar HE 0435-1223. Using deep r-band images from Subaru-Suprime-Cam we observe galaxies down to a 3σ limiting magnitude of ˜26 mags resulting in a source galaxy density of 14 galaxies / arcmin2 after redshift-based cuts. Using an inpainting technique and Multi-Scale Entropy filtering algorithm, we find that the region in close proximity to the lens has an estimated external convergence of κ =-0.012^{+0.020}_{-0.013} and is hence marginally under-dense. We also rule out the presence of any halo with a mass greater than Mvir = 1.6 × 1014h-1M⊙ (68% confidence limit). Our results, consistent with previous studies of this lens, confirm that the intervening mass along the line of sight to HE 0435-1223 does not affect significantly the cosmological results inferred from the time delay measurements of that specific object.

Large Local Void, Supernovae Type Ia, and the Kinematic Sunyaev-Zel'dovich Effect in a Lambda-LTB Model

NASA Astrophysics Data System (ADS)

Hoscheit, Benjamin L.; Barger, Amy J.

2017-06-01

There is substantial and growing observational evidence from the normalized luminosity density in the near-infrared that the local universe may be under-dense on scales of several hundred Megaparsecs. Our objective is to test whether a void described by a parameterization of the observational data is compatible with the latest data on supernovae type Ia and the linear kinematic Sunyaev-Zel'dovich (kSZ) effect. Our study is based on the large local void radial profile observed by Keenan, Barger, and Cowie (KBC) and a theoretical void description based on the Lemaître-Tolman-Bondi model with a nonzero cosmological constant (Lambda-LTB). We find consistency with the measured luminosity distance-redshift relation on radial scales relevant to the KBC void through a comparison with low-redshift supernovae type Ia from the `Supercal' dataset over the redshift range 0.01 < z < 0.10. We also find that previous linear kSZ constraints, as well as new ones from the South Pole Telescope, are fully compatible with the existence of the KBC void.

Origins of the Solar Wind

NASA Technical Reports Server (NTRS)

Warren, Harry; Gurman, Joseph (Technical Monitor)

2002-01-01

This paper presented the differential emission measure analysis of SUMER observations of a coroner streamer. We found that: The coroner streamer is isothermal at all heights. This suggests that the loops comprising the streamer must have very flat temperature profiles. The coroner streamer is "overdense" relative to the predictions of hydrostatic equilibrium at most heights. At the lowest heights the streamer is actually "underdense". The SUMER temperature measurements are not consistent with those derived from simultaneous SXT observations. SXT indicates systematically higher temperatures as well as a strong temperature gradient. These SUMER measurements yield somewhat lower temperatures and no gradient in the temperature with height. Previous work has suggested that there may be a hot component to the streamer that is preferentially observed with SXT. Our analysis shows that high temperature emission lines would be observed with SUMER if this were true and thus discounts this possibility. We suggested that scattered light in SXT might produce spurious temperature measurements. The temperature and density structure of this coroner streamer are very similar to "TRACE" active region loops (flat temperature profiles, overdense relative to uniform heating, and relatively cool temperatures).

Effects of Nonlinear Inhomogeneity on the Cosmic Expansion with Numerical Relativity.

PubMed

Bentivegna, Eloisa; Bruni, Marco

2016-06-24

We construct a three-dimensional, fully relativistic numerical model of a universe filled with an inhomogeneous pressureless fluid, starting from initial data that represent a perturbation of the Einstein-de Sitter model. We then measure the departure of the average expansion rate with respect to this homogeneous and isotropic reference model, comparing local quantities to the predictions of linear perturbation theory. We find that collapsing perturbations reach the turnaround point much earlier than expected from the reference spherical top-hat collapse model and that the local deviation of the expansion rate from the homogeneous one can be as high as 28% at an underdensity, for an initial density contrast of 10^{-2}. We then study, for the first time, the exact behavior of the backreaction term Q_{D}. We find that, for small values of the initial perturbations, this term exhibits a 1/a scaling, and that it is negative with a linearly growing absolute value for larger perturbation amplitudes, thereby contributing to an overall deceleration of the expansion. Its magnitude, on the other hand, remains very small even for relatively large perturbations.

A deeper look at the GD1 stream: density variations and wiggles

NASA Astrophysics Data System (ADS)

de Boer, T. J. L.; Belokurov, V.; Koposov, S. E.; Ferrarese, L.; Erkal, D.; Côté, P.; Navarro, J. F.

2018-06-01

Using deep photometric data from Canada-France-Hawaii Telescope/Megacam, we study the morphology and density of the GD-1 stream, one of the longest and coldest stellar streams in the Milky Way. Our deep data recovers the lower main sequence of the stream with unprecedented quality, clearly separating it from Milky Way foreground and background stars. An analysis of the distance to different parts of the stream shows that GD-1 lies at a heliocentric distance between 8 and 10 kpc, with only a shallow gradient across 45° on the sky. Matched filter maps of the stream density show clear density variations, such as deviations from a single orbital track and tentative evidence for stream fanning. We also detect a clear underdensity in the middle of the stream track at φ1 = -45° surrounded by overdense stream segments on either side. This location is a promising candidate for the elusive missing progenitor of the GD-1 stream. We conclude that the GD-1 stream has clearly been disturbed by interactions with the Milky Way disc or other subhaloes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Yongmin; Im, Myungshin; Kim, Jae-Woo, E-mail: yymx2@astro.snu.ac.kr, E-mail: mim@astro.snu.ac.kr

Under the Λ cold dark matter (ΛCDM) cosmological models, massive galaxies are expected to be larger in denser environments through frequent hierarchical mergers with other galaxies. Yet, observational studies of low-redshift early-type galaxies have shown no such trend, standing as a puzzle to solve during the past decade. We analyzed 73,116 early-type galaxies at 0.1 ≤  z  < 0.15, adopting a robust nonparametric size measurement technique and extending the analysis to many massive galaxies. We find for the first time that local early-type galaxies heavier than 10{sup 11.2} M {sub ⊙} show a clear environmental dependence in mass–size relation, in such amore » way that galaxies are as much as 20%–40% larger in the densest environments than in underdense environments. Splitting the sample into the brightest cluster galaxies (BCGs) and non-BCGs does not affect the result. This result agrees with the ΛCDM cosmological simulations and suggests that mergers played a significant role in the growth of massive galaxies in dense environments as expected in theory.« less

Higgsless approach to electroweak symmetry breaking

NASA Astrophysics Data System (ADS)

Grojean, Christophe

2007-11-01

Higgsless models are an attempt to achieve a breaking of the electroweak symmetry via boundary conditions at the end-points of a fifth dimension compactified on an interval, as an alternative to the usual Higgs mechanism. There is no physical Higgs scalar in the spectrum and the perturbative unitarity violation scale is delayed via the exchange of massive spin-1 KK resonances. The correct mass spectrum is reproduced in a model in warped space, which inherits a custodial symmetry from a left-right gauge symmetry in the bulk. Phenomenological challenges as well as collider signatures are presented. From the AdS/CFT perspective, this model appears as a weakly coupled dual to walking technicolour models. To cite this article: C. Grojean, C. R. Physique 8 (2007).

A Unix SVR-4-OS9 distributed data acquisition for high energy physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drouhin, F.; Schwaller, B.; Fontaine, J.C.

1998-08-01

The distributed data acquisition (DAQ) system developed by the GRPHE (Groupe de Recherche en Physique des Hautes Energies) group is a combination of hardware and software dedicated to high energy physics. The system described here is used in the beam tests of the CMs tracker. The central processor of the system is a RISC CPU hosted in a VME card, running a POSIX compliant UNIX system. Specialized real-time OS9 VME cards perform the instrumentation control. The main data flow goes over a deterministic high speed network. The Unix system manages a list of OS9 front-end systems with a synchronization protocolmore » running over a TCP/IP layer.« less

Fat or lean: adjustment of endogenous energy stores to predictable and unpredictable changes in allostatic load

USGS Publications Warehouse

Schultner, Jannik; Kitaysky, Alexander S.; Welcker, Jorg; Hatch, Scott

2013-01-01

6. Overall, results of this study support the ‘lean and fit’ hypothesis. We conclude that increased energy stores may not necessarily reflect better environmental conditions experienced by individuals or predict their higher fitness. A major advantage of adopting a lean physique when environmental conditions allow may be the avoidance of additional energetic costs for moving a heavy body. In breeding seabirds, this advantage may be more important during chick-rearing. In the focal species, the secretion of glucocorticoids might be involved in regulation of energy stores within a life history stage but does not appear to mediate an adaptive shift in energy stores between the incubating and chick-rearing stages of reproduction.

Imaging the experiments on respiration and transpiration of Lavoisier and Séguin: two unknown drawings by Madame Lavoisier.

PubMed

Beretta, Marco

2012-01-01

This paper presents two hitherto unknown drawings by Marie-Anne-Pierrette Lavoisier dating to the early 1790s that illustrate the experiments on respiration and transpiration of her husband Antoine-Laurent Lavoisier and his assistant Armand Séguin. These works may be associated with the well-known sepia drawings that were published for the first time by Edouard Grimaux in 1888. Details contained in these newly discovered drawings by M.me Lavoisier provide fresh evidence as to the nature and aims of Lavoisier's innovative experiments. As we will show, these drawings were intended to illustrate the collection of papers on respiration being prepared by Lavoisier for his Mémoires de physique et de chimie (1792-1805).

MASER: Measuring, Analysing, Simulating low frequency Radio Emissions.

NASA Astrophysics Data System (ADS)

Cecconi, B.; Le Sidaner, P.; Savalle, R.; Bonnin, X.; Zarka, P. M.; Louis, C.; Coffre, A.; Lamy, L.; Denis, L.; Griessmeier, J. M.; Faden, J.; Piker, C.; André, N.; Genot, V. N.; Erard, S.; King, T. A.; Mafi, J. N.; Sharlow, M.; Sky, J.; Demleitner, M.

2017-12-01

The MASER (Measuring, Analysing and Simulating Radio Emissions) project provides a comprehensive infrastructure dedicated to low frequency radio emissions (typically < 50 to 100 MHz). The four main radio sources observed in this frequency are the Earth, the Sun, Jupiter and Saturn. They are observed either from ground (down to 10 MHz) or from space. Ground observatories are more sensitive than space observatories and capture high resolution data streams (up to a few TB per day for modern instruments). Conversely, space-borne instruments can observe below the ionospheric cut-off (10 MHz) and can be placed closer to the studied object. Several tools have been developed in the last decade for sharing space physcis data. Data visualization tools developed by The CDPP (http://cdpp.eu, Centre de Données de la Physique des Plasmas, in Toulouse, France) and the University of Iowa (Autoplot, http://autoplot.org) are available to display and analyse space physics time series and spectrograms. A planetary radio emission simulation software is developed in LESIA (ExPRES: Exoplanetary and Planetary Radio Emission Simulator). The VESPA (Virtual European Solar and Planetary Access) provides a search interface that allows to discover data of interest for scientific users, and is based on IVOA standards (astronomical International Virtual Observatory Alliance). The University of Iowa also develops Das2server that allows to distribute data with adjustable temporal resolution. MASER is making use of all these tools and standards to distribute datasets from space and ground radio instruments available from the Observatoire de Paris, the Station de Radioastronomie de Nançay and the CDPP deep archive. These datasets include Cassini/RPWS, STEREO/Waves, WIND/Waves, Ulysses/URAP, ISEE3/SBH, Voyager/PRA, Nançay Decameter Array (Routine, NewRoutine, JunoN), RadioJove archive, swedish Viking mission, Interball/POLRAD... MASER also includes a Python software library for reading raw data.

PREFACE: Loops 11: Non-Perturbative / Background Independent Quantum Gravity

NASA Astrophysics Data System (ADS)

Mena Marugán, Guillermo A.; Barbero G, J. Fernando; Garay, Luis J.; Villaseñor, Eduardo J. S.; Olmedo, Javier

2012-05-01

Loops 11 The international conference LOOPS'11 took place in Madrid from the 23-28 May 2011. It was hosted by the Instituto de Estructura de la Materia (IEM), which belongs to the Consejo Superior de Investigaciones Cientĺficas (CSIC). Like previous editions of the LOOPS meetings, it dealt with a wealth of state-of-the-art topics on Quantum Gravity, with special emphasis on non-perturbative background-independent approaches to spacetime quantization. The main topics addressed at the conference ranged from the foundations of Quantum Gravity to its phenomenological aspects. They encompassed different approaches to Loop Quantum Gravity and Cosmology, Polymer Quantization, Quantum Field Theory, Black Holes, and discrete approaches such as Dynamical Triangulations, amongst others. In addition, this edition celebrated the 25th anniversary of the introduction of the now well-known Ashtekar variables and the Wednesday morning session was devoted to this silver jubilee. The structure of the conference was designed to reflect the current state and future prospects of research on the different topics mentioned above. Plenary lectures that provided general background and the 'big picture' took place during the mornings, and the more specialised talks were distributed in parallel sessions during the evenings. To be more specific, Monday evening was devoted to Shape Dynamics and Phenomenology Derived from Quantum Gravity in Parallel Session A, and to Covariant Loop Quantum Gravity and Spin foams in Parallel Session B. Tuesday's three Parallel Sessions dealt with Black Hole Physics and Dynamical Triangulations (Session A), the continuation of Monday's session on Covariant Loop Quantum Gravity and Spin foams (Session B) and Foundations of Quantum Gravity (Session C). Finally, Thursday and Friday evenings were devoted to Loop Quantum Cosmology (Session A) and to Hamiltonian Loop Quantum Gravity (Session B). The result of the conference was very satisfactory and enlightening. Not only was it a showroom for the research currently being carried out by many groups throughout the world, but there was also a permanent look towards the future. During these days, the CSIC Campus witnessed many scientific conversations triggered by the interaction amongst the people and groups that participated in LOOPS'11 Madrid and which, in many cases, will crystallise into new results and advances in the field. The conference would not have been possible without the generous help of a number of national and international institutions. The organizers would like to acknowledge the financial support provided by the Spanish Ministry of Science and Innovation (Ministerio de Ciencia e Innovación), the Spanish Research Council, CSIC (Consejo Superior de Investigaciones Cientĺficas), The BBVA Foundation (Fundación BBVA), The CONSOLIDER-CPAN project, the Spanish Society for Gravitation and Relativity (SEGRE), The Universidad Carlos III of Madrid (UC3M), and the European Science Foundation (ESF). The ESF, through the Quantum Gravity and Quantum Geometry network, provided full support for a number of young participants that have contributed to these proceedings: Dario Benedetti (Albert Einstein Institute, Potsdam, Germany), Norbert Bodendorfer (Institute for Theoretical Physics III, FAU Erlangen Nürnberg, Germany), Mariam Bouhmadi López (CENTRA, Centro Multidisciplinar de Astrofĺsica, Lisbon), Timothy Budd (Institute for Theoretical Physics, Utrecht University, The Netherlands), Miguel Campiglia (Institute for Gravitation and the Cosmos, Penn State University, USA), Gianluca Delfino (School of Mathematical Sciences, University of Nottingham, UK), Maite Dupuis (Institute for Theoretical Physics III, FAU Erlangen Nürnberg, Germany), Michał Dziendzikowski (Institute of Theoretical Physics, Warsaw University, Poland), Muxin Han (Centre de Physique Théorique de Luminy, Marseille, France), Philipp Höhn (Institute for Theoretical Physics, Utrecht University, The Netherlands), Jacek Puchta (Centre de Physique Théorique de Luminy, Marseille, France), James Ryan (Albert Einstein Institute, Potsdam, Germany), Lorenzo Sindoni (Albert Einstein Institute, Golm, Germany), David Sloan (Institute for Theoretical Physics, Utrecht University, The Netherlands), Johannes Tambornino (Laboratoire de Physique, ENS Lyon, France), Andreas Thurn (Institute for Theoretical Physics III, FAU Erlangen Nürnberg, Germany), Francesca Vidotto (Laboratoire de Physique Subatomique et de Cosmologie, Grenoble, France), and Matteo Smerlak (Albert Einstein Institute, Golm, Germany). We would like to conclude this preamble by thanking all the attendants of the conference for their high and enthusiastic participation. The presence of a large number of past and present Loop Quantum Gravity practitioners, as well as a significant number of top researchers in other approaches to quantum gravity, provided ample opportunities for fruitful scientific exchanges and a very lively atmosphere. It is encouraging to see that, 25 years after the inception of Loop Quantum Gravity, there is a vibrant young community of researchers entering the field. Let us hope that, with their help, the quantization of general relativity can be successfully accomplished in the near future. The Editors Conference photograph

[Adolphe Quetelet and biopolitics as secularized theology].

PubMed

Pich, Santiago

2013-01-01

The article recaptures the work of an author who has been forgotten by the contemporary social sciences, that is, the Belgium polymath Adolphe Quetelet. Focusing on his main work, Sur l'homme et le développement de ses facultés, ou Essai de physique sociale, the study underscores how the secularization of theological principles within the realm of science was important to the construction of Quetelet's work. His dual engagement in science and politics is pertinent here, as he was the main nineteenth-century force behind the incorporation of statistics as a science essential to the State's ability to govern its people. He also played a relevant role in the realization of the hegemonic political project of modernity, biopolitics, and its influence in the field of biomedicine in the nineteenth and twentieth centuries.

Super Yang Mills, matrix models and geometric transitions

NASA Astrophysics Data System (ADS)

Ferrari, Frank

2005-03-01

I explain two applications of the relationship between four-dimensional N=1 supersymmetric gauge theories, zero-dimensional gauged matrix models, and geometric transitions in string theory. The first is related to the spectrum of BPS domain walls or BPS branes. It is shown that one can smoothly interpolate between a D-brane state, whose weak coupling tension scales as N˜1/g, and a closed string solitonic state, whose weak coupling tension scales as N˜1/gs2. This is part of a larger theory of N=1 quantum parameter spaces. The second is a new purely geometric approach to sum exactly over planar diagrams in zero dimension. It is an example of open/closed string duality. To cite this article: F. Ferrari, C. R. Physique 6 (2005).

Laszlo Tisza and the two-fluid model of superfluidity

NASA Astrophysics Data System (ADS)

Balibar, Sébastien

2017-11-01

The "two-fluid model" of superfluidity was first introduced by Laszlo Tisza in 1938. On that year, Tisza published the principles of his model as a brief note in Nature and two articles in French in the Comptes rendus de l'Académie des sciences, followed in 1940 by two other articles in French in the Journal de physique et le Radium. In 1941, the two-fluid model was reformulated by Lev Landau on a more rigorous basis. Successive experiments confirmed the revolutionary idea introduced by Tisza: superfluid helium is indeed a surprising mixture of two fluids with independent velocity fields. His prediction of the existence of heat waves, a consequence of his model, was also confirmed. Then, it took several decades for the superfluidity of liquid helium to be fully understood.

Special Issue on "Instanton Counting: Moduli Spaces, Representation Theory, and Integrable Systems"

NASA Astrophysics Data System (ADS)

Bruzzo, Ugo; Sala, Francesco

2016-11-01

This special issue of the Journal of Geometry and Physics collects some papers that were presented during the workshop ;Instanton Counting: Moduli Spaces, Representation Theory, and Integrable Systems; that took place at the Lorentz Center in Leiden, The Netherlands, from 16 to 20 June 2014. The workshop was supported by the Lorentz Center, the ;Geometry and Quantum Theory; Cluster, Centre Européen pour les Mathématiques, la Physique et leurs Interactions (Lille, France), Laboratoire Angevin de Recherche en Mathématiques (Angers, France), SISSA (Trieste, Italy), and Foundation Compositio (Amsterdam, the Netherlands). We deeply thank all these institutions for making the workshop possible. We also thank the other organizers of the workshop, Professors Dimitri Markushevich, Vladimir Rubtsov and Sergey Shadrin, for their efforts and great collaboration.

Physiscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaumer, Olivier

2010-10-22

Peut-on survivre à une décharge de 100000 volts? Le corps humain est-il conducteur? Qu'est-ce la charge électrique? L'air est-il conducteur? Quel est le meilleur conducteur connu? Autant de question que l'on se posera durant cette découverte de la physique et le l'électricité, par une approche originale, ludique et participative. Venez glisser en lévitation sur une trottinette supraconductrice! [Can we survive a discharge of 100,000 volts? Is the human body conductive? What is the electric charge? Is the air conductive? What is the best known driver? As much question as one will ask during this discovery of the physics and the electricity, bymore » an original, playful and participative approach. Come levitate on a superconducting scooter!]« less

Que peut-on voir avec des neutrons? Une introduction pour des non spécialistes

NASA Astrophysics Data System (ADS)

Schweizer, J.

2005-11-01

Le neutron est une particule élémentaire qui a été découverte en 1932 par James Chadwick. Ses caractéristiques principales sont résumées dans le tableau I. Il a été utilisé pour la première fois par Clifford Shull en 1946 comme outil pour des expériences de diffusion. Cette technique s'est depuis constamment développée pour concerner tous les aspects de la matière condensée: physique, chimie, matériaux, biologie. Il s'agit d'un outil tout à fait exceptionnel car le neutron possède des propriétés uniques et particulièrement adaptées pour ces études.

Body checking behaviors in men.

PubMed

Walker, D Catherine; Anderson, Drew A; Hildebrandt, Thomas

2009-06-01

Males have been facing increasing pressure from the media to attain a lean, muscular physique, and are at risk for body dissatisfaction, disturbed eating and exercise behaviors, and abuse of appearance- and performance-enhancing drugs (APEDs). The aim of the current study was to examine the relationship between body checking and mood, symptoms of muscle dysmorphia, importance of shape and weight, and APED use in undergraduate males. Body checking in males was correlated with weight and shape concern, symptoms of muscle dysmorphia, depression, negative affect, and APED use. Body checking predicted APED use and uniquely accounted for the largest amount of variance in Muscle Dysmorphic Disorder Inventory (MDDI) scores (16%). Findings support the view that body checking is an important construct in male body image, muscle dysmorphia, and body change strategies and suggest a need for further research.

Analysis of time dependent phenomena observed with the LPSP OSO-8 instrument

NASA Technical Reports Server (NTRS)

Leibacher, J. W.

1979-01-01

The dynamics of the solar photosphere and chromosphere are studied. Observations obtained by the Laboratorie de Physique Stellaire et Planetaire's (LPSP) ultraviolet spectrometer onboard the OSO-8 spacecraft are analyzed, and dynamic models of the chromosphere and the emitted resonance line spectrum are calculated. Some of the unpublished data analysis and theoretical modeling which are being prepared for publication are discussed. A discussion of the state of the theory of velocity fields in the solar atmosphere is also presented. An invited review presented at the OSO-8 Workshop on the topic of oscillatory motions in the quiet sun is included. The results of the OSO-8 data analysis prepared in close collaboration with LPSP scientists are presented. Material for two articles is also presented.

Shared issues of wavefield inversion and illustrations in 3-D diffusive electromagnetics

NASA Astrophysics Data System (ADS)

Lesselier, Dominique; Lambert, Marc; Perrusson, Gaële

2005-07-01

Electromagnetic non-destructive evaluation of complex objects means that one has to decipher data which result from their interaction with imposed sources. This task is crucial in civil, environmental and medical engineering, to quote obvious fields, as well as for safety and reliability of industrial processes of various kinds in key energy and transportation sectors, for example. This short contribution does not attempt to review the huge variety of themes and the many applications of the science of inversion, but aims at emphasizing a number of points that seem common enough to this science to be worthwhile to be reviewed. Two illustrations and a few main references thought of good interest among the ever increasing literature are given. To cite this article: D. Lesselier et al., C. R. Physique 6 (2005).

Editorial: Focus on Laser- and Beam-Driven Plasma Accelerators

NASA Astrophysics Data System (ADS)

Joshi, Chan; Malka, Victor

2010-04-01

The ability of short but intense laser pulses to generate high-energy electrons and ions from gaseous and solid targets has been well known since the early days of the laser fusion program. However, during the past decade there has been an explosion of experimental and theoretical activity in this area of laser-matter interaction, driven by the prospect of realizing table-top plasma accelerators for research, medical and industrial uses, and also relatively small and inexpensive plasma accelerators for high-energy physics at the frontier of particle physics. In this focus issue on laser- and beam-driven plasma accelerators, the latest advances in this field are described. Focus on Laser- and Beam-Driven Plasma Accelerators Contents Slow wave plasma structures for direct electron acceleration B D Layer, J P Palastro, A G York, T M Antonsen and H M Milchberg Cold injection for electron wakefield acceleration X Davoine, A Beck, A Lifschitz, V Malka and E Lefebvre Enhanced proton flux in the MeV range by defocused laser irradiation J S Green, D C Carroll, C Brenner, B Dromey, P S Foster, S Kar, Y T Li, K Markey, P McKenna, D Neely, A P L Robinson, M J V Streeter, M Tolley, C-G Wahlström, M H Xu and M Zepf Dose-dependent biological damage of tumour cells by laser-accelerated proton beams S D Kraft, C Richter, K Zeil, M Baumann, E Beyreuther, S Bock, M Bussmann, T E Cowan, Y Dammene, W Enghardt, U Helbig, L Karsch, T Kluge, L Laschinsky, E Lessmann, J Metzkes, D Naumburger, R Sauerbrey, M. Scḧrer, M Sobiella, J Woithe, U Schramm and J Pawelke The optimum plasma density for plasma wakefield excitation in the blowout regime W Lu, W An, M Zhou, C Joshi, C Huang and W B Mori Plasma wakefield acceleration experiments at FACET M J Hogan, T O Raubenheimer, A Seryi, P Muggli, T Katsouleas, C Huang, W Lu, W An, K A Marsh, W B Mori, C E Clayton and C Joshi Electron trapping and acceleration on a downward density ramp: a two-stage approach R M G M Trines, R Bingham, Z Najmudin, S Mangles, L O Silva, R Fonseca and P A Norreys Electro-optic shocks from blowout laser wakefields D F Gordon, A Ting, M H Helle, D Kaganovich and B Hafizi Onset of self-steepening of intense laser pulses in plasmas J Vieira, F Fiúza, L O Silva, M Tzoufras and W B Mori Analysis of laser wakefield dynamics in capillary tubes N E Andreev, K Cassou, F Wojda, G Genoud, M Burza, O Lundh, A Persson, B Cros, V E Fortov and C-G Wahlstrom Characterization of the beam loading effects in a laser plasma accelerator C Rechatin, J Faure, X Davoine, O Lundh, J Lim, A Ben-Ismaïl, F Burgy, A Tafzi, A Lifschitz, E Lefebvre and V Malka Energy gain scaling with plasma length and density in the plasma wakefield accelerator P Muggli, I Blumenfeld, C E Clayton, F J Decker, M J Hogan, C Huang, R Ischebeck, R H Iverson, C Joshi, T Katsouleas, N Kirby, W Lu, K A Marsh, W B Mori, E Oz, R H Siemann, D R Walz and M Zhou Generation of tens of GeV quasi-monoenergetic proton beams from a moving double layer formed by ultraintense lasers at intensity 1021-1023Wcm-2 Lu-Le Yu, Han Xu, Wei-Min Wang, Zheng-Ming Sheng, Bai-Fei Shen, Wei Yu and Jie Zhang Carbon ion acceleration from thin foil targets irradiated by ultrahigh-contrast, ultraintense laser pulses D C Carroll, O Tresca, R Prasad, L Romagnani, P S Foster, P Gallegos, S Ter-Avetisyan, J S Green, M J V Streeter, N Dover, C A J Palmer, C M Brenner, F H Cameron, K E Quinn, J Schreiber, A P L Robinson, T Baeva, M N Quinn, X H Yuan, Z Najmudin, M Zepf, D Neely, M Borghesi and P McKenna Numerical modelling of a 10-cm-long multi-GeV laser wakefield accelerator driven by a self-guided petawatt pulse S Y Kalmykov, S A Yi, A Beck, A F Lifschitz, X Davoine, E Lefebvre, A Pukhov, V Khudik, G Shvets, S A Reed, P Dong, X Wang, D Du, S Bedacht, R Zgadzaj, W Henderson, A Bernstein, G Dyer, M Martinez, E Gaul, T Ditmire and M C Downer Effects of laser prepulses on laser-induced proton generation D Batani, R Jafer, M Veltcheva, R Dezulian, O Lundh, F Lindau, A Persson, K Osvay, C-G Wahlström, D C Carroll, P McKenna, A Flacco and V Malka Proton acceleration by moderately relativistic laser pulses interacting with solid density targets Erik Lefebvre, Laurent Gremillet, Anna Lévy, Rachel Nuter, Patrizio Antici, Michaël Carrié, Tiberio Ceccotti, Mathieu Drouin, Julien Fuchs, Victor Malka and David Neely Holographic visualization of laser wakefields P Dong, S A Reed, S A Yi, S Kalmykov, Z Y Li, G Shvets, N H Matlis, C McGuffey, S S Bulanov, V Chvykov, G Kalintchenko, K Krushelnick, A Maksimchuk, T Matsuoka, A G R Thomas, V Yanovsky and M C Downer The scaling of proton energies in ultrashort pulse laser plasma acceleration K Zeil, S D Kraft, S Bock, M Bussmann, T E Cowan, T Kluge, J Metzkes, T Richter, R Sauerbrey and U Schramm Plasma cavitation in ultraintense laser interactions with underdense helium plasmas P M Nilson, S P D Mangles, L Willingale, M C Kaluza, A G R Thomas, M Tatarakis, R J Clarke, K L Lancaster, S Karsch, J Schreiber, Z Najmudin, A E Dangor and K Krushelnick Radiation pressure acceleration of ultrathin foils Andrea Macchi, Silvia Veghini, Tatyana V Liseykina and Francesco Pegoraro Target normal sheath acceleration: theory, comparison with experiments and future perspectives Matteo Passoni, Luca Bertagna and Alessandro Zani Generation of a highly collimated, mono-energetic electron beam from laser-driven plasma-based acceleration Sanyasi Rao Bobbili, Anand Moorti, Prasad Anant Naik and Parshotam Dass Gupta Controlled electron acceleration in the bubble regime by optimizing plasma density Meng Wen, Baifei Shen, Xiaomei Zhang, Fengchao Wang, Zhangying Jin, Liangliang Ji, Wenpeng Wang, Jiancai Xu and Kazuhisa Nakajima A multidimensional theory for electron trapping by a plasma wake generated in the bubble regime I Kostyukov, E Nerush, A Pukhov and V Seredov Investigation of the role of plasma channels as waveguides for laser-wakefield accelerators T P A Ibbotson, N Bourgeois, T P Rowlands-Rees, L S Caballero, S I Bajlekov, P A Walker, S Kneip, S P D Mangles, S R Nagel, C A J Palmer, N Delerue, G Doucas, D Urner, O Chekhlov, R J Clarke, E Divall, K Ertel, P Foster, S J Hawkes, C J Hooker, B Parry, P P Rajeev, M J V Streeter and S M Hooker Divergence of fast ions generated by interaction of intense ultra-high contrast laser pulses with thin foils A Andreev, T Ceccotti, A Levy, K Platonov and Ph Martin The application of laser-driven proton beams to the radiography of intense laser-hohlraum interactions G Sarri, C A Cecchetti, L Romagnani, C M Brown, D J Hoarty, S James, J Morton, M E Dieckmann, R Jung, O Willi, S V Bulanov, F Pegoraro and M Borghesi Laser-driven particle and photon beams and some applications K W D Ledingham and W Galster Target shape effects on monoenergetic GeV proton acceleration Min Chen, Tong-Pu Yu, Alexander Pukhov and Zheng-Ming Sheng

Competition entre supraconductivite et magnetisme au voisinage de la transition de Mott dans le conducteur organique quasi-bidimensionnel k-(BEDT-TTF)2copper[N(CN)2]bromine

NASA Astrophysics Data System (ADS)

Fournier, David

Les conducteurs organiques quasi-bidimensionnels kappa-ET2X presentent d'importantes similitudes avec les SCHT telles qu'une phase isolant de Mott, un regime de pseudogap et un etat supraconducteur. L'etude de leurs proprietes apparait donc complementaire. Parmi les interrogations persistantes concernant la physique de ces systemes, l'origine du (ou des) processus exotique d'appariement, responsable de la supraconductivite est le sujet suscitant l'interet le plus marque dans la communaute. L'hypothese d'un mecanisme lie a la proximite d'un etat antiferromagnetique est privilegiee. Une etape importante dans la resolution de cette problematique est l'identification de la symetrie du parametre d'ordre. D'apres de nombreux travaux sur les systemes fortement correles, la sonde ultrasonore, de par sa sensibilite aux excitations de quasiparticule a basse temperature, est consideree comme particulierement adaptee a l'etude de cette propriete. Cependant, son emploi necessite l'utilisation d'un compose metallique a basse temperature et completement supraconducteur. Le compose metallique organique kappa-ET 2Cu[N(CN)2]Br presente toutes les caracteristiques necessaires a l'etude de cette propriete. En effet, il est situe loin de la transition du premier ordre de Mott et est completement supraconducteur. De facon surprenante, ce systeme semble se coupler fortement avec le reseau ce qui augmente significativement la sensibilite de cette sonde aux proprietes du gaz electronique. Cependant, des difficultes techniques importantes, liees a la nature intrinseque de ce materiau, doivent etre surmontees pour proceder a des mesures suivant differentes polarisations. La presente etude a profondement modifie notre comprehension de ce systeme. En effet, ces mesures ont permis de constater que le kappa-ET2Cu[N(CN)2]Br est un compose qui est situe en bordure de la zone de coexistence entre la supraconductivite et le magnetisme, ce qui constitue un resultat totalement inattendu. De plus, la variation judicieuse du cycle thermique s'est averee etre equivalente a une modification de la pression chimique. Cette derniere est modifiee par l'intermediaire d'une relaxation structurale autour de 85 K appelee la transition de verre d'ethylenes. Cela nous a permis de suivre l'evolution de cette coexistence en s'approchant de la transition de premier ordre, et ainsi de statuer sur la competition entre la supraconductivite et le magnetisme ainsi que sur l'existence d'une separation de phase d'ordre macroscopique. De plus, nous avons observe une anisotropie similaire sur les mesures de vitesse ultrasonore entre le regime de pseudogap et la supraconductivite. Ce resultat tend a confirmer l'existence d'une physique commune entre le regime de pseudogap et l'etat supraconducteur. Le regime de pseudogap, encore meconnu a ce jour, est probablement relie a des fluctuations antiferromagnetiques, dont l'origine pourrait etre un emboitement de la surface de Fermi quasi-unidimensionnelle de ce compose, ou bien relie a la proximite de la physique de Mott. Enfin, l'analyse de la symetrie du parametre d'ordre supraconducteur, qui est probablement de type s+d, tend a demontrer que les processus de couplage interplan sont d'une importance cruciale. L'approche theorique de Hubbard purement 2D dans le plan conducteur semble donc insuffisante pour la recherche du mecanisme d'appariement.

Statistical model of quiet Sun coronal heating (French Title: Modèle statistique de chauffage de la couronne solaire calme)

NASA Astrophysics Data System (ADS)

Podladchikova, O.

2002-02-01

The high temperature of the solar corona is still a puzzling problem of solar physics. However, the recent observations of satellites SoHO, Yohkoh or TRACE seem to indicate that the processes responsible for the heating of the closed regions are situated in the low corona or in the chromosphere, thus close to the sun surface, and are associated to the direct currents dissipation. Statistical data analysis suggest that the heating mechanisms result thus from numerous events of current layers dissipation of small scale and weak energy, on the resolution limit of modern instruments. We propose a statistical lattice model, resulting from an approach more physical than self-organized criticality, constituted by a magnetic energy source at small scales and by dissipation mechanisms of the currents, which can be associated either to magnetic reconnection or to anomalous resistivity. The various types of sources and mechanisms of dissipation allow to study their influence on the statistical properties of the system, in particular on the energy dissipation. With the aim of quantifying this behavior and allowing detailed comparisons between models and observations, analysis techniques little used in solar physics, such as the singular values decomposition, entropies, or Pearson technique of PDF classification are introduced and applied to the study of the spatial and temporal properties of the model. La température anormalement élevée de la couronne reste un des problèmes majeurs de la physique solaire. Toutefois, les observations récentes des satellites SoHO, Yohkoh ou TRACE semblent indiquer que les processus responsables du chauffage des régions fermées se situent dans la basse couronne ou dans la chromosphère, donc proches de la surface solaire, et sont associés à la dissipation de couches de courant continu. L'analyse statistique de données suggère que les mécanismes de chauffage résulteraient donc de nombreux événements de dissipation de couches de courant de petite échelle et de faible énergie, àla limite de la résolution des instruments modernes. Nous proposons un modèle statistique sur réseau, résultant d'une approche plus physique que la criticalité auto-organisée, constitué d'une source d'énergie magnétique de petite échelle et de mécanismes de dissipation des courants, qui peuvent être associés soit à la reconnection magnétique soit à la résistivité anormale. Les différents types de sources et de mécanismes de dissipation permettent d'étudier leur influence sur les propriétés statistiques du système, en particulier sur l'énergie dissipée. Dans le but de quantifier ces comportements et de permettre des comparaisons approfondies entres les modèles et les observations, des techniques d'analyse peu utilisées en physique solaire, telles que la décomposition en valeurs singulières, des entropies, ou la technique de Pearson de classification des densités de probabilité, sont introduites et appliquées `a l'étude des propriétés spatiales et temporelles du modèle.

Multi-parameter observation of environmental asbestos pollution at the Institut de Physique du Globe de Paris (Jussieu Campus, France).

PubMed

Besson, P; Lalanne, F X; Wang, Y; Guyot, F

1999-11-01

An original multi-parameter system has been used to study the nature of dust in the ambient air, particularly the total fibers and asbestos fibers, in eight areas of the Institut de Physique de Globe de Paris (France). These analyses provide a detailed case study of environmental pollution by asbestos fibers at low levels. The levels of total fibers with a length greater than 3 microns, measured with a real time fiber analyser monitor (FAM), give a baseline of 2.5 fibers per l., throughout the duration of sampling. The same levels, calculated during periods of effective presence of staff, are smaller than 10 fb per l. During these periods, the instantaneous value can show high peaks, reaching a maximum of 60 fb per l., but more often of about 5 to 10 fb per l. A direct cause and effect relationship exists between fiber concentrations and the presence of people, and indirectly with the variation of the other environmental parameters (temperature, humidity, air velocity). The baseline concentration of asbestos fibers, determined by analytical transmission electron microscopy (ATEM), is about 10(-1) fb per l., with a mean value during the presence of people always less than 1.5 fb per l. The low levels of asbestos fibers do not allow us to establish a precise correlation between the concentration of total fibers and the asbestos concentration, but a rough estimate suggests that asbestos could represent 10-20% of the airborne fibers monitored with the FAM. The statistical study of fiber sizes shows that 70 and 55% of analyzed chrysotile and amosite fibers respectively are smaller than 5 microns. These numbers are 40 and 35% for fibers smaller than 3 microns, which are undetected by the FAM. Amosite, which characterizes most of the asbestos-containing materials (ACM) in the analyzed areas, is detected in the ambient air in quantities ten times less important than chrysotile. The low asbestos levels and the difference between the nature of building asbestos and airborne fibers, show that the mean measured asbestos contents in the ambient air represent the geochemical background of chrysotile asbestos fibers in the Parisian air.

Relationship of body mass index to percent body fat and waist circumference among schoolchildren in Japan--the influence of gender and obesity: a population-based cross-sectional study.

PubMed

Ochiai, Hirotaka; Shirasawa, Takako; Nishimura, Rimei; Morimoto, Aya; Shimada, Naoki; Ohtsu, Tadahiro; Kujirai, Emiko; Hoshino, Hiromi; Tajima, Naoko; Kokaze, Akatsuki

2010-08-18

Although the correlation coefficient between body mass index (BMI) and percent body fat (%BF) or waist circumference (WC) has been reported, studies conducted among population-based schoolchildren to date have been limited in Japan, where %BF and WC are not usually measured in annual health examinations at elementary schools or junior high schools. The aim of the present study was to investigate the relationship of BMI to %BF and WC and to examine the influence of gender and obesity on these relationships among Japanese schoolchildren. Subjects included 3,750 schoolchildren from the fourth and seventh grade in Ina-town, Saitama Prefecture, Japan between 2004 and 2008. Information about subject's age, sex, height, weight, %BF, and WC was collected from annual physical examinations. %BF was measured with a bipedal biometrical impedance analysis device. Obesity was defined by the following two criteria: the obese definition of the Centers for Disease Control and Prevention, and the definition of obesity for Japanese children. Pearson's correlation coefficients between BMI and %BF or WC were calculated separately for sex. Among fourth graders, the correlation coefficients between BMI and %BF were 0.74 for boys and 0.97 for girls, whereas those between BMI and WC were 0.94 for boys and 0.90 for girls. Similar results were observed in the analysis of seventh graders. The correlation coefficient between BMI and %BF varied by physique (obese or non-obese), with weaker correlations among the obese regardless of the definition of obesity; most correlation coefficients among obese boys were less than 0.5, whereas most correlations among obese girls were more than 0.7. On the other hand, the correlation coefficients between BMI and WC were more than 0.8 among boys and almost all coefficients were more than 0.7 among girls, regardless of physique. BMI was positively correlated with %BF and WC among Japanese schoolchildren. The correlations could be influenced by obesity as well as by gender. Accordingly, it is essential to consider gender and obesity when using BMI as a surrogate for %BF and WC for epidemiological use.

La supraconductivité a 100 ans !

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebrun, Philippe

2011-04-14

Il y a 100 ans, le 8 avril 1911, une découverte majeure était réalisée : celle de la supraconductivité. La supraconductivité est la caractéristique qu’ont certains métaux et alliages de perdre toute résistance électrique en dessous d’une température donnée. Cette renversante découverte, réalisée de manière presque fortuite par Kammerlingh Onnes de l’Université de Leyde (Pays-Bas) et son étudiant Gilles Holst, a ouvert un nouveau champ de recherche en physique et de fabuleuses perspectives d’applications technologiques. Du point de vue scientifique, la supraconductivité est en effet l’une des rares manifestations de la physique quantique à l’échelle macroscopique.  Du point de vuemore » des retombées techniques, elle est porteuse d’applications majeures dans le domaine de la santé, des communications et de l’énergie. 100 ans après, les physiciens n’ont toujours pas fini d’explorer ce phénomène et ses applications. Le CERN abrite des applications de la supraconductivité à des échelles inédites. L’accélérateur de particules LHC, avec ses milliers d’aimants supraconducteurs répartis sur 27 kilomètres de circonférence, est en effet la plus grande application mondiale de la supraconductivité. Il ne pourrait exister sans elle. Le CERN fête donc la découverte de la supraconductivité avec une conférence exceptionnelle donnée par Philippe Lebrun. Au cours de cette conférence, l’expérience historique de Kammerlingh Onnes sera reproduite. Philippe Lebrun racontera l’histoire de cette étonnante découverte, en la replaçant dans le contexte scientifique de l’époque. Il racontera les développements scientifiques et les applications du premier siècle de la supraconductivité. Conférence en français Merci de bien vouloir vous inscrire au : +41 22 767 76 76 ou cern.reception@cern.ch« less

Beyond Flory theory: Distribution functions for interacting lattice trees

NASA Astrophysics Data System (ADS)

Rosa, Angelo; Everaers, Ralf

2017-01-01

While Flory theories [J. Isaacson and T. C. Lubensky, J. Physique Lett. 41, 469 (1980), 10.1051/jphyslet:019800041019046900; M. Daoud and J. F. Joanny, J. Physique 42, 1359 (1981), 10.1051/jphys:0198100420100135900; A. M. Gutin et al., Macromolecules 26, 1293 (1993), 10.1021/ma00058a016] provide an extremely useful framework for understanding the behavior of interacting, randomly branching polymers, the approach is inherently limited. Here we use a combination of scaling arguments and computer simulations to go beyond a Gaussian description. We analyze distribution functions for a wide variety of quantities characterizing the tree connectivities and conformations for the four different statistical ensembles, which we have studied numerically in [A. Rosa and R. Everaers, J. Phys. A: Math. Theor. 49, 345001 (2016), 10.1088/1751-8113/49/34/345001 and J. Chem. Phys. 145, 164906 (2016), 10.1063/1.4965827]: (a) ideal randomly branching polymers, (b) 2 d and 3 d melts of interacting randomly branching polymers, (c) 3 d self-avoiding trees with annealed connectivity, and (d) 3 d self-avoiding trees with quenched ideal connectivity. In particular, we investigate the distributions (i) pN(n ) of the weight, n , of branches cut from trees of mass N by severing randomly chosen bonds; (ii) pN(l ) of the contour distances, l , between monomers; (iii) pN(r ⃗) of spatial distances, r ⃗, between monomers, and (iv) pN(r ⃗|l ) of the end-to-end distance of paths of length l . Data for different tree sizes superimpose, when expressed as functions of suitably rescaled observables x ⃗=r ⃗/√{ } or x =l / . In particular, we observe a generalized Kramers relation for the branch weight distributions (i) and find that all the other distributions (ii-iv) are of Redner-des Cloizeaux type, q (x ⃗) =C |x| θexp(-(K|x |) t) . We propose a coherent framework, including generalized Fisher-Pincus relations, relating most of the RdC exponents to each other and to the contact and Flory exponents for interacting trees.

Restauration fonctionnelle du rachis : effet du niveau initial de douleur sur les performances des sujets lombalgiques chroniques

PubMed Central

Caby, Isabelle; Olivier, N; Mendelek, F; Kheir, R Bou; Vanvelcenaher, J; Pelayo, P

2014-01-01

HISTORIQUE : La lombalgie chronique est une douleur lombaire persistante d’origine multifactorielle. Le niveau de douleur initial reste faiblement utilisé pour analyser et comparer les réponses des patients lombalgiques au programme de reconditionnement. OBJECTIFS : Apprécier et évaluer les réponses des sujets lombalgiques chroniques très douloureux à une prise en charge dynamique et intensive. MÉTHODOLOGIE : 144 sujets atteints de lombalgie chronique ont été inclus dans un programme de restauration fonctionnelle du rachis de 5 semaines. Les sujets ont été classés en deux groupes de niveau de douleur: un groupe atteint de douleur sévère (n = 28) et un groupe atteint de douleur légère à modérée (n = 106). L’ensemble des sujets ont bénéficié d’une prise en charge identique comprenant principalement de la kinésithérapie, de l’ergothérapie, du reconditionnement musculaire et cardio-vasculaire ainsi qu’un suivi psychologique. Les paramètres physiques (flexibilité, force musculaire) et psychologiques (qualité de vie) ont été mesurés avant (T0) et après le programme (T5sem). RÉSULTATS : L’ensemble des performances physiques et fonctionnelles des sujets très douloureux sont moins bonnes et le retentissement de la lombalgie sur la qualité de vie, pour ces mêmes sujets, est majoré à T0. Toutes les différences significatives constatées à T0 entre les deux groupes s’effacent à T5sem. CONCLUSIONS : Les sujets lombalgiques chroniques très douloureux répondent favorablement au programme dynamique et intensif. L’intensité douloureuse de la lombalgie n’aurait pas d’effet sur les réponses au programme. La restauration fonctionnelle du rachis apporterait aux sujets la possibilité de mieux gérer leur douleur quel que soit son niveau. PMID:25299476

Dépistage des maladies cardiovasculaires chez des étudiants de l'Université de Douala et influence des activités physiques et sportives

PubMed Central

Ewane, Marielle Epacka; Mandengue, Samuel Honoré; Priso, Eugene Belle; Tamba, Stéphane Moumbe; Ahmadou; Fouda, André Bita

2012-01-01

Introduction Les maladies cardiovasculaires (MCV) constituent l'une des principales causes de mortalité dans les pays en développement. Le dépistage de ces dernières chez des jeunes est un défi dans la lutte contre leur expansion. Le but de cette étude était de dépister ces maladies au sein d'une population jeunes d’étudiants camerounais. Methodes Deux mille six cent cinquante-huit étudiants de l'Université de Douala (23,6 ± 2,9 ans, sex-ratio H/F = 0,9) ont en Avril - Mai 2011 participé à une campagne de dépistage gratuit du diabète, de l'hypertension artérielle (HTA) et de l'obésité. Ils ont également été soumis à une d'enquête évaluant leur niveau en activités physiques et sportives (APS). Resultats 12,7% des participants avaient une pression artérielle (PA) ≥ 140/90 mmHg, 3,6% étaient obèses et 0,9% avaient une glycémie ≥1,26 g/L. Des corrélations ont été trouvées entre certains facteurs de risque (diabète, hypertension et obésité) et le niveau académique d'une part (r =0,366; p < 0,0001) et le temps passé devant la télévision d'autres part (r = 0,411; p < 0,0001). L‘APS était inversement corrélée à l‘âge (r =-0,015; p < 0,0001) et au temps passé devant la télévision (r = -0,059; p = 0,002). Conclusion La présence des MCV et leurs facteurs de risque mis en évidence dans cette étude réalisée en milieu estudiantin camerounais interpelle à une prévention et une éducation dans la lutte contre ces dernières. PMID:22655111

Une recension des écrits concernant la réalité psychoaffective des femmes ayant une vulvodynie : Difficultés rencontrées et stratégies développées

PubMed Central

Cantin-Drouin, Maude; Damant, Dominique; Turcotte, Daniel

2008-01-01

HISTORIQUE : Au cours des trois dernières décennies, une attention grandissante a été portée à l’étude du syndrome de vulvodynie, soit un inconfort vulvaire chronique inexpliqué, éprouvé en l’absence de pathologie précisée. En plus d’avoir des répercussions physiques, l’expérience de la vulvodynie comporte une dimension psychosociale. OBJECTIF : Cet article vise à faire une recension des écrits sur la réalité psychoaffective des femmes qui éprouvent une vulvodynie. MÉTHODE : Une recherche documentaire basée sur une exploration systématique de textes présentant des résultats de recherche et recensés dans les principales banques de données en sciences sociales, dont Dissertation Abstracts, Current Contents et PsycINFO, a été réalisée. RÉSULTATS : Cette recension des écrits révèle, malgré la présence de certains résultats divergents, que les femmes ayant une vulvodynie affrontent souvent des difficultés identitaires et psychologiques, qui sont influencées notamment par les normes sociales de sexualité et de féminité. Pour composer avec ces difficultés, les femmes développent différentes stratégies visant à diminuer le stress occasionné par la douleur et à améliorer leur bien-être psychologique. CONCLUSION : Les difficultés relationnelles et psychologiques vécues par les femmes ayant une vulvodynie ne découlent pas seulement de la douleur physique, mais aussi du sens qu’elles lui accordent, souvent influencé par les discours sociaux sur l’hétérosexualité et la féminité. Il importe donc d’intervenir auprès des femmes en tenant compte de l’influence du contexte social tout en poursuivant le développement des connaissances sur les aspects psychosociaux de cette expérience. PMID:18592063

No 129-L'exercice physique pendant la grossesse et le postpartum.

PubMed

Davies, Gregory A L; Wolfe, Larry A; Mottola, Michelle F; MacKinnon, Catherine

2018-02-01

Énoncer une directive canadienne visant à informer les fournisseurs de soins obstétricaux des répercussions, pour la mère, le fœtus et le nouveau-né, des exercices de conditionnement aerobique et musculaire pendant la grossesse. RéSULTATS ATTENDUS: Effets sur la morbidité maternelle, fœtale et néonatale et mesures de la forme physique maternelle. Une recherche sur MEDLINE des articles, publiés en anglais de 1966 à 2002, appartenant aux catégories suivantes : études sur le conditionnement aérobique et musculaire chez des femmes ne faisant pas jusque-là d'exercice et chez des femmes actives avant leur grossesse, ainsi que des études sur les répercussions du conditionnement aérobique et musculaire sur les issues précoces et tardives de la grossesse ou sur les issues néonatales; rapports de synthèse et méta-analyses portant sur l'exercice pendant la grossesse. Les résultats recueillis ont été revus par la Société des obstétriciens et gynécologues du Canada (Comité de la pratique clinique - obstétrique), avec la participation de la Société canadienne de physiologie de l'exercice, et ils ont été classés suivant les critères d'évaluation des preuves établis par le Groupe de travail canadien sur l'examen de santé périodique. VALIDATION: Cette directive a été approuvée par le Comité de pratique clinique - obstétrique de la SOGC, par le Comité exécutif et par le Conseil de la SOGC, ainsi que par le Conseil d'administration de la Société canadienne de physiologie de l'exercice. PARRAINé PAR: la Société des obstétriciens et gynécologues du Canada et par la Société canadienne de physiologie de l'exercice. Copyright © 2018. Published by Elsevier Inc.

The nature of the companion star in Circinus X-1

NASA Astrophysics Data System (ADS)

Johnston, Helen M.; Soria, Roberto; Gibson, Joel

2016-02-01

We present optical spectra and images of the X-ray binary Circinus X-1. The optical light curve of Cir X-1 is strongly variable, changing in brightness by 1.2 mag in the space of four days. The shape of the light curve is consistent with that seen in the 1980s, when the X-ray and radio counterparts of the source were at least ten times as bright as they are currently. We detect strong, variable H α emission lines, consisting of multiple components which vary with orbital phase. We estimate the extinction to the source from the strength of the diffuse interstellar bands and the Balmer decrement; the two methods give AV = 7.6 ± 0.6 mag and AV > 9.1 mag, respectively. The optical light curve can be modelled as arising from irradiation of the companion star by the central X-ray source, where a low-temperature star fills its Roche lobe in an orbit of moderate eccentricity (e ˜ 0.4). We suggest that the companion star is overluminous and underdense, due to the impact of the supernova which occurred less than 5000 yr ago.

Exploratory investigations of hypervelocity intact capture spectroscopy

NASA Technical Reports Server (NTRS)

Tsou, P.; Griffiths, D. J.

1993-01-01

The ability to capture hypervelocity projectiles intact opens a new technique available for hypervelocity research. A determination of the reactions taking place between the projectile and the capture medium during the process of intact capture is extremely important to an understanding of the intact capture phenomenon, to improving the capture technique, and to developing a theory describing the phenomenon. The intact capture of hypervelocity projectiles by underdense media generates spectra, characteristic of the material species of projectile and capture medium involved. Initial exploratory results into real-time characterization of hypervelocity intact capture techniques by spectroscopy include ultra-violet and visible spectra obtained by use of reflecting gratings, transmitting gratings, and prisms, and recorded by photographic and electronic means. Spectrometry proved to be a valuable real-time diagnostic tool for hypervelocity intact capture events, offering understanding of the interactions of the projectile and the capture medium during the initial period and providing information not obtainable by other characterizations. Preliminary results and analyses of spectra produced by the intact capture of hypervelocity aluminum spheres in polyethylene (PE), polystyrene (PS), and polyurethane (PU) foams are presented. Included are tentative emission species identifications, as well as gray body temperatures produced in the intact capture process.