24,095 research outputs found
Screening in (2+1)D pure gauge theory at high temperatures
We compute heavy quark potentials in pure gauge at high temperatures
in dimensions and confront them with expectations emerging from
perturbative calculations.Comment: 3 pages, latex, 4 figures, uu, Contribution to LATTICE 9
RELATIONSHIP OF BIOMECHANICAL AND PSYCHOLOGICAL PARAMETERS BETWEEN PRACTICE AND COMPETITION IN POLE VAULTING
The purpose of this study was to examine relationships of biomechanical parameters, cognitive anxiety, somatic anxiety, and self confidence changes between competition and practice in the pole vault. Seven pole vaulters were videotaped in practice and competition and completed the Competition Sport Anxiety Inventory-2 (CSAI-2). A Pearson Correlation was computed to examine relationships between the difference score of the means for the competition and practice vaults of all the parameters. Several significant correlations were found (
Can the frequency-dependent specific heat be measured by thermal effusion methods?
It has recently been shown that plane-plate heat effusion methods devised for
wide-frequency specific-heat spectroscopy do not give the isobaric specific
heat, but rather the so-called longitudinal specific heat. Here it is shown
that heat effusion in a spherical symmetric geometry also involves the
longitudinal specific heat.Comment: Paper presented at the Fifth International Workshop on Complex
Systems (Sendai, September, 2007), to appear in AIP Conference Proceeding
Differential Very Long Baseline Interferometry (delta VLBI) spacecraft tracking system demonstration. Part 2: Data acquisition and processing
A set of experiments in the use of Differential Very Long Baseline Interferometry (delta VLBI) for spacecraft navigation were completed. Data using both Voyager spacecraft and a single quasar were acquired during the Jupiter encounter time period. The data were processed and analyzed to assess the navigation accuracy of delta VLBI. The data reduction and techniques for assessing data quality and consistency are discussed
Simulating spin-3/2 particles at colliders
Support for interactions of spin-3/2 particles is implemented in the
FeynRules and ALOHA packages and tested with the MadGraph 5 and CalcHEP event
generators in the context of three phenomenological applications. In the first,
we implement a spin-3/2 Majorana gravitino field, as in local supersymmetric
models, and study gravitino and gluino pair-production. In the second, a
spin-3/2 Dirac top-quark excitation, inspired from compositness models, is
implemented. We then investigate both top-quark excitation and top-quark
pair-production. In the third, a general effective operator for a spin-3/2
Dirac quark excitation is implemented, followed by a calculation of the angular
distribution of the s-channel production mechanism.Comment: 20 pages, 7 figure
Germinability Factors of Field-Grown Sorghum Seed
Germination of sorghum seed did not appear to be affected by spraying the plants with Maneb or with a chemical defoliant before harvest. Mechanical threshing greatly reduced germination of most but not all lots; this injury is thought to be related to the maturity and/ or moisture content of the seed when threshed, although other varietal differences may be important. At any given time there were large differences in moisture content between seeds of different hybrids, different plants of any one hybrid, and between different parts of the same panicle
KINEMATIC CHANGES AT BALL RELEASE IN BASEBALL PITCHING OVER A SIMULATED GAME OF BASEBALL
INTRODUCTION The defensive nature of baseball causes it to be dominated by the skill of the pitcher, who through speed of pitch or a combination of speed and guile in controlling the ball often determines the result of the game (Polk, 1982). Correct pitching mechanics enables a pitcher to throw the ball repeatedly at high velocities without undue risk of injury. Nowhere is this more important than in the late innings of a game. PURPOSES AND METHODS The purpose of this study was to kinematically describe and compare the changes in stride length, foot contact, ball release time, release height, ball velocity and knee, hip, and trunk angle at ball release over a simulated single game of baseball pitching in collegiate pitchers. Seven male collegiate pitchers were filmed pitching a simulated , 7inning baseball game. Each inning consisted of 14 pitches following the protocol as suggested by Potteiger, Blessing, and Wilson (1992). Every other pitch was to be thrown with 100% effort while the other pitches were to be thrown at 80% effort. The first, seventh, and thirteenth pitches of innings 1,4, and 7 were required to be fast balls and were filmed using the Peak5 2D video system. Film data were collected at 120 Hz. A Jugs radar gun was used to collect the velocity of the baseballs being pitched. A 3 x 3 analysis of variance with an alpha level set at
Supercooled Liquid Dynamics Studied via Shear-Mechanical Spectroscopy
We report dynamical shear-modulus measurements for five glass-forming liquids
(pentaphenyl trimethyl trisiloxane, diethyl phthalate, dibutyl phthalate,
1,2-propanediol, and m-touluidine). The shear-mechanical spectra are obtained
by the piezoelectric shear-modulus gauge (PSG) method. This technique allows
one to measure the shear modulus ( Pa) of the liquid within a
frequency range from 1 mHz to 10 kHz. We analyze the frequency-dependent
response functions to investigate whether time-temperature superposition (TTS)
is obeyed. We also study the shear-modulus loss-peak position and its
high-frequency part. It has been suggested that when TTS applies, the
high-frequency side of the imaginary part of the dielectric response decreases
like a power law of the frequency with an exponent -1/2. This conjecture is
analyzed on the basis of the shear mechanical data. We find that TTS is obeyed
for pentaphenyl trimethyl trisiloxane and in 1,2-propanediol while in the
remaining liquids evidence of a mechanical process is found. Although
the the high-frequency power law behavior of the shear-loss
may approach a limiting value of when lowering the temperature, we
find that the exponent lies systematically above this value (around 0.4). For
the two liquids without beta relaxation (pentaphenyl trimethyl trisiloxane and
1,2-propanediol) we also test the shoving model prediction, according to which
the the relaxation-time activation energy is proportional to the instantaneous
shear modulus. We find that the data are well described by this model.Comment: 7 pages, 6 figure
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