155 research outputs found
Laser Doppler velocimeter aerial spray measurements
An experimental research program for measuring the location, spatial extent, and relative concentration of airborne spray clouds generated by agricultural aircraft is described. The measurements were conducted with a ground-based laser Doppler velocimeter. The remote sensing instrumentation, experimental tests, and the results of the flight tests are discussed. The cross section of the aerial spray cloud and the observed location, extent, and relative concentration of the airborne particulates are presented. It is feasible to use a mobile laser Doppler velocimeter to track and monitor the transport and dispersion of aerial spray generated by an agricultural aircraft
Preliminary design for a standard 10 sup 7 bit Solid State Memory (SSM)
A modular concept with three separate modules roughly separating bubble domain technology, control logic technology, and power supply technology was employed. These modules were respectively the standard memory module (SMM), the data control unit (DCU), and power supply module (PSM). The storage medium was provided by bubble domain chips organized into memory cells. These cells and the circuitry for parallel data access to the cells make up the SMM. The DCU provides a flexible serial data interface to the SMM. The PSM provides adequate power to enable one DCU and one SMM to operate simultaneously at the maximum data rate. The SSM was designed to handle asynchronous data rates from dc to 1.024 Mbs with a bit error rate less than 1 error in 10 to the eight power bits. Two versions of the SSM, a serial data memory and a dual parallel data memory were specified using the standard modules. The SSM specification includes requirements for radiation hardness, temperature and mechanical environments, dc magnetic field emission and susceptibility, electromagnetic compatibility, and reliability
A selected ion flow tube study of the reactions of gas-phase cations with PSCl3
A selected ion flow tube was used to investigate the positive ion chemistry of thiophosphoryl chloride, PSCl. Rate coefficients and ion product branching ratios have been determined at room temperature for reactions with nineteen cations ; HO, CF, CF, NO, NO, SF, SF, CF, O, HO, NO, O, CO, CO, N, N, Ar, F and Ne (in order of increasing recombination energy). Complementary data described in the previous paper have been obtained for this molecule via the observation of threshold photoelectron photoion coincidences. For ions whose recombination energies are in the range 10-22 eV, comparisons are made between the product ion branching rations of PSCl from photoionisation and from ion-molecule reactions. In most instances, the data from the two experiments are well correlated, suggesting that long-range charge transfer is the dominant mechanism for these ion-molecule reactions ; the agreement is particularly good for the atomic ions Ar, F and Ne. Some reactions (e.g. O + PSCl), however, exhibit significant differences; short-range charge transfer must then be occurring following the formation of an ion-molecule complex. For ions whose recombination energies are less than 10 eV (i.e. HO, CF, CF and NO), reactions can only occur via a chemical process in which bonds are broken and formed, because the recombination energy of the cation is less than the ionisation energy of PSCl
Remote measurement utilizing NASA's scanning laser Doppler systems. Volume 2: Laser Doppler dust devil velocity profile measurement program
The first detailed velocity profile data on thermally induced dust vortices are presented. These dust devils will be analyzed and studied to determine their flow fields and origin in an effort to correlate this phenomena with the generation and characteristics of tornadoes. A continuing effort to increase mankind's knowledge of vortex and other meteorological phenomena will hopefully allow the prediction of tornado occurrence, their path, and perhaps eventually even lead to some technique for their destruction
The photoionization dynamics of the three structural isomers of dichloroethene
Using tunable vacuum-UV radiation from a synchrotron, the threshold photoelectron spectrum, threshold photoelectron photoion coincidence spectrum and ion breakdown diagram of the 1,1, cis-1,2 and trans-1,2 isomers of CHCl have been recorded in the range 9-23 eV. The energies of the peaks in the threshold photoelectron spectrum are in good agreement with outer-valence Greens function caculations. The major difference between the isomers, both predicted and observed experimentally is that the Fï€ and Gï€ states of CHCl are approximately degenerate for 1,1 and trans-1,2, but well separated for the cis-1,2 isomer. The ground and low-lying valence states of CHCl are bound, with higher-lying states dissociating to CHCl or CH. The translational kinetic energy release into CHCl + Cl is determined as a function of energy. Isolated-state behaviour for the low-lying electronic states of CHCl becomes more statistical as the energy increases
Stand-off identification of aerosols using mid-infrared backscattering fourier-transform spectroscopy
Workload profiles prior to injury in professional soccer players
© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. This study examined if a particular profile of internal and external workload existed prior to injury. Forty-five professional soccer players were monitored over two seasons. For each non-contact injury, a profile of workload variables was determined for 4 weeks and expressed as (i) an absolute, (ii) week-to-week change and (iii) relative to the player’s season mean. Variables included exposure, session rating of perceived exertion (s-RPE) workload, total distance, low-, high-, very-high-speed running distance, mean speed, bodyload, monotony and strain. Acute:chronic workload ratio was also calculated and sensitivity of the relative workload was tested. Absolute and relative exposure and s-RPE workload were greater in all 3 weeks compared to the injury week (P  0.05). Acute:chronic workload ratio for s-RPE was significantly greater than acute:chronic workload ratio for very-high-speed running (P = 0.04). A workload threshold of 114% of a player’s season mean reported low sensitivity and specificity for exposure (25.6[20.2–33.5]% and 73.9[22.6–28.2]%,) and s-RPE workload (16.3[12.6–24.9]% and 79.9[20.3–26.1]%, respectively). No specific load profile existed, although high-sustained exposure and s-RPE were evident for the 3 weeks prior to injury. Consequently, load prescription should be aware of sustained high workloads
Effects of northbound long-haul international air travel on sleep quantity and subjective jet lag and wellness in professional Australian soccer players
© 2015 Human Kinetics, Inc. The current study examined the effects of 10-h northbound air travel across 1 time zone on sleep quantity, together with subjective jet lag and wellness ratings, in 16 male professional Australian football (soccer) players. Player wellness was measured throughout the week before (home training week) and the week of (away travel week) travel from Australia to Japan for a preseason tour. Sleep quantity and subjective jet lag were measured 2 d before (Pre 1 and 2), the day of, and for 5 d after travel (Post 1-5). Sleep duration was significantly reduced during the night before travel (Pre 1; 4.9 [4.2-5.6] h) and night of competition (Post 2; 4.2 [3.7-4.7] h) compared with every other night (P 0.90). Moreover, compared with the day before travel, subjective jet lag was significantly greater for the 5 d after travel (P 0.90), and player wellness was significantly lower 1 d postmatch (Post 3) than at all other time points (P 0.90). Results from the current study suggest that sleep disruption, as a result of an early travel departure time (8 PM) and evening match (7:30 PM), and fatigue induced by competition had a greater effect on wellness ratings than long-haul air travel with a minimal time-zone change. Furthermore, subjective jet lag may have been misinterpreted as fatigue from sleep disruption and competition, especially by the less experienced players. Therefore, northbound air travel across 1 time zone from Australia to Asia appears to have negligible effects on player preparedness for subsequent training and competition
Femtosecond-laser pumped CdSiP<sub>2</sub> optical parametric oscillator producing 100 MHz pulses centered at 6.2 μm
Determining Stroke and Movement Profiles in Competitive Tennis Match-Play From Wearable Sensor Accelerometry.
ABSTRACT: Perri, T, Reid, M, Murphy, A, Howle, K, and Duffield, R. Determining stroke and movement profiles in competitive tennis match-play from wearable sensor accelerometry. J Strength Cond Res XX(X): 000-000, 2022-This study determined stroke and movement accelerometry metrics from a wearable sensor and compared between court surface (grass vs. hard) and match outcome (win vs. loss) during competitive tennis match-play. Eight junior high-performance tennis players wore a trunk-mounted global positioning system, with in-built accelerometer, magnetometer, and gyroscope during singles matches on hard and grass courts. The manufacturer software calculated accelerometer-derived total player load (tPL). A prototype algorithm classified forehands, backhands, serves, and "other" strokes, thereby calculating stroke PL (sPL) from individual strokes. Movement PL (mPL) was calculated as the difference between tPL and sPL, with all metrics reported as absolute and relative (min-1, %, and ·stroke). Analysis of accelerometer load and stroke count metrics was performed through a two-way (surface [grass vs. hard] × match outcome [win vs. loss]) analysis of variance (p 0.05). Increased mPL% featured on grass courts, whereas sPL% was increased on hard courts (p = 0.04, d = 1.18[0.31-2.02]). Elevated sPL·min-1 existed on hard courts (p = 0.04, d = 1.19[0.32-2.04]), but no differences in tPL·min-1 and mPL·min-1 were evident for surface or outcome (p > 0.05). Relative forehand sPL (FH-sPL·min-1) was higher on hard courts (p = 0.03, d = 1.18[0.31-2.02]) alongside higher forehand counts (p = 0.01, d = 1.29[0.40-2.14]). Hitting demands are heightened on hard courts from increased sPL and counts. Conversely, increased mPL% on grass courts likely reflects the specific movement demands from point-play. Physical preparation strategies during training blocks can be tailored toward movement or hitting loads to suit competitive surfaces
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