The Physical and Physiological Demands of Elite International Female Field Hockey Players During Competitive Match-Play.

The aim of the current investigation was to quantify the physical and physiological demands of elite international female field hockey match-play across halves of play. Thirty-eight participants (24 ± 5 years; 173 ± 5 cm; 72 ± 5 kg) took part in nineteen competitive matches during the 2014 - 2015 season. Participants were monitored with GPS technology and heart rate monitors. Players were categorized based on three different playing positions. Activity was categorized into total (m), high-speed running distance (m; >16 km·h) and relative distance (m·min) due to the use of rolling substitutions. Heart rate was classified based on the percentage of players individual HRpeak determined via a Yo-Yo intermittent recovery level 1 test. Players spent on average 44 ± 7 min in match-play. The total distance covered was 5558 ± 527 m (125 ± 23 m·min) with 589 ± 160 m (13 ± 4 m·min) completed at high-speed. Defenders covered a greater total distance compared to other positions of play (p ≤ 0.001). Midfield players covered a greater distance at high-speed (p ≤ 0.001) with the forwards having a higher relative distance (p ≤ 0.001). The HRpeak of the players was 199 ± 1 bmin with a mean exercise intensity of 86 ± 7.8 % of HRpeak. The time spent >85% HRpeak decreased significantly across the halves (p = 0.04, η = 0.09, Small). Defenders were found to spend more time >85 % HRpeak when compared to forwards (p ≤ 0.001). The current investigation provides normative data that coaches should consider when constructing training regimen

Quasi-Particle Spectra, Charge-Density-Wave, Superconductivity and Electron-Phonon Coupling in 2H-NbSe2

High-resolution photoemission has been used to study the electronic structure of the charge density wave (CDW) and superconducting (SC) dichalcogenide, 2H- NbSe2. From the extracted self-energies, important components of the quasiparticle (QP) interactions have been identified. In contrast to previously studied TaSe2, the CDW transition does not affect the electronic properties significantly. The electron-phonon coupling is identified as a dominant contribution to the QP self-energy and is shown to be very anisotropic (k-dependent) and much stronger than in TaSe2.Comment: 4 pages, 3 figures, minor changes, to appear in PR

Photon pair-state preparation with tailored spectral properties by spontaneous four-wave mixing in photonic-crystal fiber

We study theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in photonic crystal optical fiber. We show that it is possible to engineer two-photon states with specific spectral correlation (``entanglement'') properties suitable for quantum information processing applications. We focus on the case exhibiting no spectral correlations in the two-photon component of the state, which we call factorability, and which allows heralding of single-photon pure-state wave packets without the need for spectral post filtering. We show that spontaneous four wave mixing exhibits a remarkable flexibility, permitting a wider class of two-photon states, including ultra-broadband, highly-anticorrelated states.Comment: 17 pages, 7 figures, submitte

3d absorption-spectra of Sr I through Sr IV

The extreme ultraviolet photoabsorption spectra of neutral to three-times-ionized strontium have been recorded in a comprehensive series of experiments with the dual laser-produced plasma technique. Striking differences were found in the spectra, which can be attributed to the transfer of oscillator strength from 3d→np to 3d→nf transitions at Sr2+ due to nf wave-function contraction. In Sr and Sr+, 3d→5p transitions dominate; in Sr2+, 3d→nf transitions are most intense, while in Sr3+ the 4p subshell opens and 3d→4p transitions are the strongest features. Partial cross sections for 3d→ɛf and 3d→ɛp photoionization were calculated and compared with experiment

Design of a releasable snowboard binding system to prevent upper body injury

The objective of this project was to design, build, and test a snowboard binding system that prevents upper body injury to snowboarders due to the flyswatter effect . This effect occurs when the user catches the longitudinal edge of the snowboard during turns, swinging the user\u27s upper body towards the terrain. The system was designed to release under shear stress caused by the effect, and a moment lock mechanism activated by normal riding forces was integrated to prevent inadvertent release