551 research outputs found
THREE-DIMENSIONAL DYNAMIC ANALYSIS FOR THE LOWER EXTREMITY DURING FASTBALL BASEBALL PITCH
Five collegiate baseball pitchers, who have different types of delivery, were videotaped and analyzed using three-dimensional videography and ground reaction force (GRF) anaysis. Just before stride foot contact, a peak vertical GRF of 1.28 BW for pivot foot was produced, resulting from the joint torques for the knee and hip extensors. A peak forward GRF of 0.67 BW also appeared. This GRF may result in the ankle plantar flexors. Immediately after stride foot contact, the joint torques of hipâs extension, abduction and internal rotation, kneeâs extension and valgus, ankleâs plantar flexion for the striding leg were generated in order to resist the resultant of vertical and backward GRFs
Decaying shock studies of phase transitions in MgOSiO2 systems: implications for the Super-Earths interiors
We report an experimental study of the phase diagrams of periclase (MgO),
enstatite (MgSiO3) and forsterite (Mg2SiO4) at high pressures. We investigated
with laser driven decaying shocks the pressure/temperature curves of MgO,
MgSiO3 and Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa and 0.2-0.85 TPa
respectively. A melting signature has been observed in MgO at 0.47 TPa and 9860
K, while no phase changes were observed neither in MgSiO3 nor in Mg2SiO4. An
increasing of reflectivity of MgO, MgSiO3 and Mg2SiO4 liquids have been
detected at 0.55 TPa -12 760 K, 0.15 TPa - 7540 K, 0.2 TPa - 5800 K,
respectively. In contrast to SiO2, melting and metallization of these compounds
do not coincide implying the presence of poor electrically conducting liquids
close to the melting lines. This has important implications for the generation
of dynamos in Super-earths mantles
Classification of singular Q-homology planes. I. Structure and singularities
A Q-homology plane is a normal complex algebraic surface having trivial
rational homology. We obtain a structure theorem for Q-homology planes with
smooth locus of non-general type. We show that if a Q-homology plane contains a
non-quotient singularity then it is a quotient of an affine cone over a
projective curve by an action of a finite group respecting the set of lines
through the vertex. In particular, it is contractible, has negative Kodaira
dimension and only one singular point. We describe minimal normal completions
of such planes.Comment: improved results from Ph.D. thesis (University of Warsaw, 2009), 25
pages, to appear in Israel J. Mat
Laser-Shock Compression and Hugoniot Measurements of Liquid Hydrogen to 55 GPa
The principal Hugoniot for liquid hydrogen was obtained up to 55 GPa under
laser-driven shock loading. Pressure and density of compressed hydrogen were
determined by impedance-matching to a quartz standard. The shock temperature
was independently measured from the brightness of the shock front. Hugoniot
data of hydrogen provide a good benchmark to modern theories of condensed
matter. The initial number density of liquid hydrogen is lower than that for
liquid deuterium, and this results in shock compressed hydrogen having a higher
compression and higher temperature than deuterium at the same shock pressure.Comment: 8 pages, 7 figures, 2 tables, accepted for publication in Physical
Review
A New Upper Limit for the Tau-Neutrino Magnetic Moment
Using a prompt neutrino beam in which a nu_tau component was identified for
the first time, the nu_tau magnetic moment was measured based on a search for
an anomalous increase in the number of neutrino-electron interactions. One such
event was observed when 2.3 were expected from background processes, giving an
upper 90% confidence limit of 3.9x10^-7 Bohr magnetons.Comment: 9 pages; 1 figur
Schottky barrier height of MnSb(0001)/GaAs(111)B contacts:Influence of interface structure
The Schottky barrier height (SBH) of MnSb(0001)/n-GaAs(111)B diodes was investigated in terms of current-voltage characteristics for three different GaAs surfaces, GaAs (root 19x root 19), GaAs (2x2), and sulfur passivated GaAs. We observed that the SBH and the ideality factor changed significantly depending on the GaAs surface structure prepared before the MnSb growth. The sulfur passivated sample was superior to the others in that it has a lower ideality factor and higher barrier. The SBH fell off linearly with increasing ideality factor n. The SBH of MnSb(0001)/n-GaAs(111)B was estimated to be 0.94 eV by extrapolating the linear relationship to n=1. (C) 2000 American Institute of Physics. [S0021-8979(00)02916-9]
Distance measurements between 5 nanometer diamonds â single particle magnetic resonance or optical super-resolution imaging?
5 nanometer sized detonation nanodiamonds (DNDs) are studied as potential single-particle labels for distance measurements in biomolecules
Observation of nu_tau appearance in the CNGS beam with the OPERA experiment
The OPERA experiment is searching for nu_mu -> nu_tau oscillations in
appearance mode i.e. via the direct detection of tau leptons in nu_tau charged
current interactions. The evidence of nu_mu -> nu_tau appearance has been
previously reported with three nu_tau candidate events using a sub-sample of
data from the 2008-2012 runs. We report here a fourth nu_tau candidate event,
with the tau decaying into a hadron, found after adding the 2012 run events
without any muon in the final state to the data sample. Given the number of
analysed events and the low background, nu_mu -> nu_tau oscillations are
established with a significance of 4.2sigma.Comment: Submitted to Progress of Theoretical and Experimental Physics (PTEP
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