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Sample records for lx-17 hockey puck

  1. Ignition and Growth Modeling of LX-17 Hockey Puck Experiments

    SciTech Connect

    Tarver, C M

    2004-04-19

    Detonating solid plastic bonded explosives (PBX) formulated with the insensitive molecule triaminotrinitrobenzene (TATB) exhibit measurable reaction zone lengths, curved shock fronts, and regions of failing chemical reaction at abrupt changes in the charge geometry. A recent set of ''hockey puck'' experiments measured the breakout times of diverging detonation waves in ambient temperature LX-17 (92.5 % TATB plus 7.5% Kel-F binder) and the breakout times at the lower surfaces of 15 mm thick LX-17 discs placed below the detonator-booster plane. The LX-17 detonation waves in these discs grow outward from the initial wave leaving regions of unreacted or partially reacted TATB in the corners of these charges. This new experimental data is accurately simulated for the first time using the Ignition and Growth reactive flow model for LX-17, which is normalized to a great deal of detonation reaction zone, failure diameter and diverging detonation data. A pressure cubed dependence for the main growth of reaction rate yields excellent agreement with experiment, while a pressure squared rate diverges too quickly and a pressure quadrupled rate diverges too slowly in the LX-17 below the booster equatorial plane.

  2. A comparison of the capacity of ice hockey goaltender masks for the protection from puck impacts.

    PubMed

    Nur, Sarah; Kendall, Marshall; Clark, J Michio; Hoshizaki, T Blaine

    2015-11-01

    Goaltenders in ice hockey are the only players that are on the ice for the entire game. Their position exposes them to impacts from collisions with other players, falls to the ice, and puck impacts. In competitive ice hockey leagues, head injuries resulting from puck impacts have been reported with some cases resulting in ending the player's career. Considerable research has been conducted to assess the performance of hockey helmets; however, few have assessed the performance of goaltenders' masks. The purpose of this study was to compare the capacity of four goaltenders' masks for the protection from puck impact as measured by head acceleration and peak force. A Hybrid III headform was fitted with four different goaltender masks and impacted with a hockey puck in three locations at 25 m/s. The masks were found to vary in the level of protection they offered as the mask with the thickest liner resulted in lower forces than the thinnest mask for side impacts; however, the thinnest mask resulted in the lowest force for front impacts. Despite performance differences at specific locations, no one mask proved to be superior as peak acceleration and peak force values did not exceed the thresholds necessary for concussion. PMID:26644178

  3. Exploitation of a "hockey-puck" phenotype to identify pilus and biofilm regulators in Serratia marcescens through genetic analysis.

    PubMed

    Shanks, Robert M Q; Stella, Nicholas A; Brothers, Kimberly M; Polaski, Denise M

    2016-01-01

    Pili are essential adhesive determinants for many bacterial pathogens. A suppressor mutation screen that takes advantage of a pilus-mediated self-aggregative "hockey-puck" colony phenotype was designed to identify novel regulators of type I pili in Serratia marcescens. Mutations that decreased pilus biosynthesis mapped to the fimABCD operon; to the genes alaT, fkpA, and oxyR; upstream of the flagellar master regulator operon flhDC; and to an uncharacterized gene encoding a predicted DUF1401 domain. Biofilm formation and pilus-dependent agglutination assays were used to characterize the relative importance of the identified genes in pilus biosynthesis. Additional mutagenic or complementation analysis was used to verify the role of candidate genes in pilus biosynthesis. Presented data support a model that CRP negatively regulates pilus biosynthesis through increased expression of flhDC and decreased expression of oxyR. Further studies are warranted to determine the mechanism by which these genes mediate pilus biosynthesis or function. PMID:26640000

  4. Air Gap Effects in LX-17

    SciTech Connect

    Souers, P C; Ault, S; Avara, R; Bahl, K L; Boat, R; Cunningham, B; Gidding, D; Janzen, J; Kuklo, D; Lee, R; Lauderbach, L; Weingart, W C; Wu, B; Winer, K

    2005-09-26

    Three experiments done over twenty years on gaps in LX-17 are reported. For the detonation front moving parallel to the gaps, jets of gas products were seen coming from the gaps at velocities greater than the detonation velocity. A case can be made that the jet velocity increased with gap thickness but the data is scattered. For the detonation front moving transverse to the gap, time delays were seen. The delays roughly increase with gap width, going from 0-70 ns at 'zero gap' to around 300 ns at 0.5-1 mm gap. Larger gaps of up to 6 mm width almost certainly stopped the detonation, but this was not proved. Real-time resolution of the parallel jets and determination of the actual re-detonation or failure in the transverse case needs to be done in future experiments.

  5. LX-17 and ufTATB Data for Corner-Turning, Failure and Detonation

    SciTech Connect

    Souers, P C; Lauderbach, L; Garza, R; Vitello, P; Hare, D E

    2010-02-03

    Data is presented for the size (diameter) effect for ambient and cold confined LX-17, unconfined ambient LX-17, and confined ambient ultrafine TATB. Ambient, cold and hot double cylinder corner-turning data for LX-17, PBX 9502 and ufTATB is presented. Transverse air gap crossing in ambient LX-17 is studied with time delays given for detonations that cross.

  6. LX-17 Deflagration at High Pressures and Temperatures

    SciTech Connect

    Koerner, J; Maienschein, J; Black, K; DeHaven, M; Wardell, J

    2006-10-23

    We measure the laminar deflagration rate of LX-17 (92.5 wt% TATB, 7.5 wt% Kel-F 800) at high pressure and temperature in a strand burner, thereby obtaining reaction rate data for prediction of thermal explosion violence. Simultaneous measurements of flame front time-of-arrival and temporal pressure history allow for the direct calculation of deflagration rate as a function of pressure. Additionally, deflagrating surface areas are calculated in order to provide quantitative insight into the dynamic surface structure during deflagration and its relationship to explosion violence. Deflagration rate data show that LX-17 burns in a smooth fashion at ambient temperature and is represented by the burn rate equation B = 0.2P{sup 0.9}. At 225 C, deflagration is more rapid and erratic. Dynamic deflagrating surface area calculations show that ambient temperature LX-17 deflagrating surface areas remain near unity over the pressure range studied.

  7. Detonation Shock Dynamics (DSD) Calibration for LX-17

    SciTech Connect

    Aslam, Tariq D

    2012-04-24

    The goal of this report is to summarize the results of a Detonation shock dynamics (DSD) calibration for the explosive LX-17. Considering that LX-17 is very similar to PBX 9502 (LX-17 is 92.5% TATB with 7.5% Kel-F 800 binder, while PBX 9502 is 95% TATB with 5% Kel-F 800 binder), we proceed with the analysis assuming many of the DSD constants are the same. We only change the parameters D{sub CJ}, B and {bar C}{sub 6} ({bar C}{sub 6} controls the how D{sub CJ} changes with pressing density). The parameters D{sub CJ} and {bar C}{sub 6} were given by Josh Coe and Sam Shaw's EOS. So, only B was optimized in fitting all the calibration data. This report first discusses some general DSD background, followed by a presentation of the available dataset to perform the calibration, and finally gives the results of the calibration and draws some conclusions. A DSD calibration of LX-17 has been conducted using the existing diameter effect data and shock shape records. The new DSD fit is based off the current PBX 9502 calibration and takes into account the effect of pressing density. Utilizing the PBX 9502 calibration, the effects of initial temperature can also be taken into account.

  8. Dead Zones in LX-17 and PBX 9502

    SciTech Connect

    Souers, P C; Andreski, H G; Batteux, J; Bratton, B; Cabacungan, C; Cook, III, C F; Fletcher, S; Garza, R; Grimsley, D; Handly, J; Hernandez, A; McMaster, P; Molitoris, J D; Palmer, R; Prindiville, J; Rodriguez, J; Schneberk, D; Wong, B; Vitello, P

    2005-09-06

    Pin and X-ray corner-turning data have been taken on ambient LX-17 and PBX 9052, and the results are listed in tables as an aid to future modeling. The results have been modeled at 4 zones/mm with a reactive flow approach that varies the burn rate as a function of pressure. A single rate format is used to simulate failure and detonation in different pressure regimes. A pressure cut-off must also be reached to initiate the burn. Corner-turning and failure are modeled using an intermediate pressure rate region, and detonation occurs at high pressure. The TATB booster is also modeled using reactive flow, and X-ray tomography is used to partition the ram-pressed hemisphere into five different density regions. The model reasonably fits the bare corner-turning experiment but predicts a smaller dead zone with steel confinement, in contradiction with experiment. The same model also calculates the confined and unconfined cylinder detonation velocities and predicts the failure of the unconfined cylinder at 3.75 mm radius. The PBX 9502 shows a smaller dead zone than LX-17. An old experiment that showed a large apparent dead zone in Comp B was repeated with X-ray transmission and no dead zone was seen. This confirms the idea that a variable burn rate is the key to modeling. The model also produces initiation delays, which are shorter than those found in time-to-detonation.

  9. LX-17 Corner-Turning and Reactive Flow Failure

    SciTech Connect

    Souers, P C; Andreski, H; Cook III, C F; Garza, R; Pastrone, R; Phillips, D; Roeske, F; Vitello, P; Molitoris, J

    2004-03-11

    We have performed a series of highly-instrumented experiments examining corner-turning of detonation. A TATB booster is inset 15 mm into LX-17 (92.5% TATB, 7.5% kel-F) so that the detonation must turn a right angle around an air well. An optical pin located at the edge of the TATB gives the start time of the corner-turn. The breakout time on the side and back edges is measured with streak cameras. Three high-resolution X-ray images were taken on each experiment to examine the details of the detonation. We have concluded that the detonation cannot turn the corner and subsequently fails, but the shock wave continues to propagate in the unreacted explosive, leaving behind a dead zone. The detonation front farther out from the corner slowly turns and eventually reaches the air well edge 180{sup o} from its original direction. The dead zone is stable and persists 7.7 {micro}s after the corner-turn, although it has drifted into the original air well area. Our regular reactive flow computer models sometimes show temporary failure but they recover quickly and are unable to model the dead zones. We present a failure model that cuts off the reaction rate below certain detonation velocities and reproduces the qualitative features of the corner-turning failure.

  10. Mesoscale Modeling of LX-17 Under Isentropic Compression

    SciTech Connect

    Springer, H K; Willey, T M; Friedman, G; Fried, L E; Vandersall, K S; Baer, M R

    2010-03-06

    Mesoscale simulations of LX-17 incorporating different equilibrium mixture models were used to investigate the unreacted equation-of-state (UEOS) of TATB. Candidate TATB UEOS were calculated using the equilibrium mixture models and benchmarked with mesoscale simulations of isentropic compression experiments (ICE). X-ray computed tomography (XRCT) data provided the basis for initializing the simulations with realistic microstructural details. Three equilibrium mixture models were used in this study. The single constituent with conservation equations (SCCE) model was based on a mass-fraction weighted specific volume and the conservation of mass, momentum, and energy. The single constituent equation-of-state (SCEOS) model was based on a mass-fraction weighted specific volume and the equation-of-state of the constituents. The kinetic energy averaging (KEA) model was based on a mass-fraction weighted particle velocity mixture rule and the conservation equations. The SCEOS model yielded the stiffest TATB EOS (0.121{micro} + 0.4958{micro}{sup 2} + 2.0473{micro}{sup 3}) and, when incorporated in mesoscale simulations of the ICE, demonstrated the best agreement with VISAR velocity data for both specimen thicknesses. The SCCE model yielded a relatively more compliant EOS (0.1999{micro}-0.6967{micro}{sup 2} + 4.9546{micro}{sup 3}) and the KEA model yielded the most compliant EOS (0.1999{micro}-0.6967{micro}{sup 2}+4.9546{micro}{sup 3}) of all the equilibrium mixture models. Mesoscale simulations with the lower density TATB adiabatic EOS data demonstrated the least agreement with VISAR velocity data.

  11. Corner turning and shock desensitization experiments plus numerical modeling of detonation waves in the triaminotrinitrobenzene based explosive LX-17.

    PubMed

    Tarver, Craig M

    2010-03-01

    Five new experiments are reported that tested both detonation wave corner turning and shock desensitization properties of the triaminotrinitrobenzene (TATB) based plastic bonded explosive (PBX) LX-17. These experiments used small pentaerythritol tetranitrate (PETN) charges to initiate hemispherical ultrafine TATB (UF TATB) boosters, which then initiated LX-17 hemispherical detonations. The UF TATB boosters were placed under steel shadow plates embedded in the LX-17 cylindrical charges, which were covered by thin aluminum plates. The LX-17 detonation waves propagated outward until they reached the aluminum plates, which were instrumented with photonic Doppler velocimetry probes to measure their axial free surface velocities. X-ray radiographs and framing camera images were taken at various times. The LX-17 detonations propagated around the two corners of the steel shadow plates and into thin LX-17 layers placed between the steel and the top aluminum plates. The detonation waves were met there by weak diverging shocks that propagated through the steel plates and imparted 1-2 GPa pressures to these unreacted LX-17 layers. These weak shock waves compressed and desensitized the unreacted LX-17, resulting in failures of the LX-17 detonation waves. The hydrodynamics of double corner turning and shock desensitization in the five experiments were modeled in two dimensions using the Ignition and Growth LX-17 detonation reactive flow model. The calculated arrival times and axial free surface velocity histories of the top aluminum plates were in excellent agreement with the experimental measurements. PMID:20141191

  12. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    SciTech Connect

    Souers, P C; Hernandez, A; Cabacungan, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2008-02-05

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in 0 reactive flow JWL++ and Linked Cheetah V4, mostly at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. The physical basis of the input parameters is considered.

  13. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    SciTech Connect

    Souers, P C; Hernandez, A; Cabacungen, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2007-05-30

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in the Linked Cheetah V4.0 reactive flow code at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. A report card of 25 tests run with the same settings on LX-17 is shown, possibly the most extensive simultaneous calibration yet tried with an explosive. The physical basis of some of the input parameters is considered.

  14. A Comparison of New TATBs, FK-800 binder and LX-17-like PBXs to Legacy Materials

    SciTech Connect

    Willey, T M; DePiero, S C; Hoffman, D M

    2009-05-01

    Two newly synthesized versions of the insensitive high explosive (IHE) 1,3,5-triamino-2,4,6-trinitrobenzenes (TATBs) were compared to two legacy explosives currently used by the Department of Energy. Except for thermal analysis, small scale safety tests could not distinguish between the different synthetic routes. Morphologies of new TATBs were less faceted and more spherical. The particle size distribution of one new material was similar to legacy TATBs, but the other was very fine. Densities and submicron structure of the new TATBs were also significantly different from the legacy explosives. Pressed pellets of the new explosives were less dense. New FK-800 binder was used to prepare LX-17-like plastic bonded explosives (PBXs) from new and wet aminated TATB. Some mechanical, thermal and performance characterization of the new binder and LX-17-like PBXs was done. Significant differences were found. The reason for a number of these differences is not well understood.

  15. Development of a Detonation Profile Test for Studying Aging Effects in LX-17

    SciTech Connect

    Tran, T; Lewis, P; Tarver, C; Maienschein, J; Druce, R; Lee, R; Roeske, F

    2002-03-25

    A new small-scale Detonation Profile Test (DPT) is being developed to investigate aging effects on the detonation behavior of insensitive high explosives. The experiment involves initiating a small LX-17 cylindrical charge (12.7-19.1 mm diameter x 25.4-33 mm long) and measuring the velocity and curvature of the emerging detonation wave using a streak camera. Results for 12.7 mm diameter unconfined LX-17 charges show detonation velocity in the range between 6.79 and 7.06 km/s for parts up to 33 mm long. Since LX-17 can not sustain detonation at less than 7.3 km/s, these waves were definitely failing. Experiments with confined 12.7 mm diameter and unconfined 19.1 mm diameter samples showed wave velocities in the range of 7.4-7.6 km/s, values approaching steady state conditions at infinite diameter. Experiments with unconfined 19.1 mm diameter specimens are expected to provide reproducible and useful range of detonation parameters suitable for studying aging effects.

  16. Characterization of Detonation Wave Propagation in LX-17 Near the Critical Diameter

    SciTech Connect

    Tran, T D; Tarver, C M; Maienschein, J; Lewis, P; Pastrone, R; Lee, R S; Roeske, F

    2002-06-14

    A new Detonation Profile Test (DPT) was developed to measure simultaneously the detonation wave breakout profile and the average detonation velocity at the breakout surface. The test evaluated small cylindrical samples with diameter up to 19.08 mm and length up to 33 mm. The experiment involved initiating a LX-17 cylindrical specimen and recording the wave breakout using a fast streaking electronic camera. The initiation was done using a PBX-9407 pellet (1.630 g/cm{sup 3}), which has a Chapman-Jouguet (C-J) pressure close to that of LX-17. The acceptor breakout surface had a 2 mm wide by 1 mm deep groove that provided a step in the recorded breakout profile for velocity determination. A 532-nm laser light illuminated the specimen surface. A streak camera looking perpendicular to the groove, recorded the extinction of the laser light as the detonation wave emerged from the surface. This technique provided a high-resolution spatial and temporal profile of the wave curvature as well as accurate timing of the propagating wave over the last millimeter of the sample. The measured groove depth and recorded travel time were then used to calculate the average detonation wave velocity. Results for 12.7 mm diameter unconfined LX-17 charges showed detonation velocity in the range between 6.79 and 7.06 km/s for parts up to 33 mm long. Since LX-17 can not sustain detonation at less than 7.3 km/s , these waves were definitely failing. Experiments with confined 12.7 mm diameter and unconfined 19.1 mm diameter samples showed wave velocities in the range of 7.4-7.6 km/s, values approaching steady state conditions at infinite diameter. Both unconfined and confined charges show no sensitivity to density variations in the range between 1.890-1.915 g/cm{sup 3}. Experiments with 15.88 mm and 19.08 mm diameters gave velocities in the range between 7.2-7.45 km/s, values close to that expected for failure. The velocity measurement has an estimated experimental error in the range of 2%, which is large enough to complicate data analysis. The Ignition and Growth model for LX-17 was compared to the results. The effects of density, confinement and charge diameter on wave breakout profiles and detonation wave velocity were accurately reproduced. A comparative analysis of the experimental breakout patterns and the calculated wave curvatures for the densities and dimensions was also determined.

  17. First-Generation Jet Propulsion Laboratory "Hockey-Puck" Free-Flying Magnetometers for Distributed In-Situ Multiprobe Measurement of Current Density Filamentation in the Northern Auroral Zone: Enstrophy Mission

    NASA Technical Reports Server (NTRS)

    Javadi, H.; Blaes, B.; Boehm, M.; Boykins, K.; Gibbs, J.; Goodman, W.; Lieneweg, U.; Lux, J.; Lynch, K.; Narvaez, P.

    2000-01-01

    The sub-orbital rocket mission was a collaborative project between the University of New Hampshire, Cornell University, and the Jet Propulsion Laboratory (JPL) to study filamentation phenomena in the northern Auroral zone. The Enstrophy mission test flies the JPL Free-Flying Magnetometer (FFM) concept. The FFM technology development task has been funded by NASA develop miniaturized, low-power, integrated "sensorcrafts". JPL's role was to design, integrate, test, and deliver four FFMs for deployment from the sounding rocket, allowing a unique determination of curl-B. This provides a direct measurement of magnetic-field-aligned current density along the rocket trajectory. A miniaturized three-axis fluxgate magnetometer was integrated with a 4-channel 22-bit sigma-delta Analog to Digital Converter (ADC), four temperature sensors, digital control electronics, seven (Li-SOCl2) batteries, two (4 deg x 170 deg field of view) sun-sensors, a fan-shaped-beam laser diode beacon, a (16 MHz) stable Temperature Compensated Crystal Oscillator (TCXO) clock, Radio Frequency (RF) communication subsystem, and an antenna for approximately 15 minutes of operation where data was collected continuously and transmitted in three (3) bursts (approximately 26 seconds each) to ground station antennas at Poker Flat, Alaska. FFMs were stowed within two trays onboard the rocket during the rocket launch and were released simultaneously using the spinning action of the rocket at approximately 300 km altitude (approximately 100 sec. into the flight). FFMs were deployed with spin rate of approximately 17 Hz and approximately 3 m/sec linear velocity with respect to the rocket. For testing purposes while the rocket was in the launch pad and during flight prior to release of FFMs from the rocket, commands (such as "power on", "test", "flight", "power off', and clock "Reset" signal) were transmitted via a infrared Light Emitting Diode to an infrared detector in the FFM. Special attention was paid to low magnetic signature electronic design and choice of materials in packaging. The miniaturized fluxgate magnetometers had a range of 1-60000 nT with 0.1% full-scale linearity. The frequency range of interest for magnetic measurement was 10 mHz - 50 Hz. Digital data from the magnetometer's three axes were placed in a 4MB Static Random Access Memory (SRAM) in data packages (frames) formatted together with time tags and frame ID. After a specified time was elapsed, the data were Viterbi encoded and transmitted at a rate of 100 kbps (BPSK). Each of the four FFMs transmitted at different frequency. These carrier frequencies were in the range of 2200-2300 MHz. The antenna was a single patch on a high dielectric constant substrate covering one end-plate of the hockey-puck-sized unit. The local clocks aboard the FFMs were reset at the start of the mission and stayed synchronized within 3 msec during the mission. Position of each FFM with respect to the rocket is calculated by the knowledge of its release velocity (measured at exit point of the FFM launcher tract) providing an accuracy of 1 m over the maximum range of 3 km. Spatial and temporal nature of observants can be separated to within 3 m in space or 3 msec time interval.

  18. ALE3D Statistical Hot Spot Model Results for LX-17

    SciTech Connect

    Nichols, A L III; Tarver, C M; McGuire, E M

    2003-07-11

    The Statistical Hot Spot shock initiation and detonation reactive flow model for solid explosives in the ALE3D hydrodynamic computer code provides physically realistic descriptions of: hot spot formation; ignition (or failure to ignite); growth of reaction (or failure to grow) into surrounding particles; coalescence of reacting hot spots; transition to detonation; and self-sustaining detonation. The model has already successfully modeled several processes in HMX-based explosives, such as shock desensitization, that can not predicted by other reactive flow models. In this paper, the Statistical Hot Spot model is applied to experimental embedded gauge data on the insensitive triaminotrintrobenzene (TATB) based explosive LX-17.

  19. Vulnerability of hot LX-17 to lightning strikes on exposed detonator and actuator cables

    SciTech Connect

    Chau, H.H.; Osher, J.E.; Von Holle, W.G.; Lee, R.S.; Moua, K.

    1993-12-01

    Capacitor bank discharges with peak currents up to 700 kA were used to explode test sections of detonator cable and launch the dielectric material on top of the exploding conductor as a fast flyer plate. Velocity of the launched material, pressure profiles from the impact of the launched material and impact marks formed in aluminum witness plates were used to study the stimulus that could be transmitted to high explosive in the vicinity of the exploding cable. To quantify the risk of initiating the main charge or booster insensitive high explosive (IHE) in a weapon, one must know the threshold stimulus required for shock initiation. LX-17 samples, heated to temperatures up to 250C were impacted by 3 to 10-mm-wide stripes of 0.12-mm-thick Kapton to determine the initiation threshold velocity at ambient and elevated temperatures, The strips simulate the impact of the cover coat of a flat detonator cable which has been exploded by a lighting strike. The data allow us to assess the likelihood that a lightning strike on the cable would be able to initiate a detonation of the LX- 17 main charge.

  20. Re-Shock Experiments in LX-17 to Investigate Reacted Equation of State

    NASA Astrophysics Data System (ADS)

    Vandersall, Kevin S.; Forbes, Jerry W.; Tarver, Craig M.; Urtiew, Paul A.; Garcia, Frank

    2001-06-01

    Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed utilizing a 101 mm gun to measure the reacted state of LX-17 using a re-shock method. This method involves backing the energetic material with thin plates (of a known equation of state) that reflect a shock back into the detonated material. Thus, by measuring the parameters of this reflected wave information on the reacted state can be obtained. The experiments were driven by a projectile to near the CJ state ensuring a quick transition to detonation near the front of the sample. Embedded electromagnetic particle velocity (EMV) gauges were used to measure the particle velocity profiles at different Lagrange positions during the event. Calibration of this technique was accomplished by using an elastic material as the target where the known state could be measured and evaluated. A discussion of this work will include the experimental setup, particle velocity profiles, data interpretation, and future experiments. *This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

  1. Eye injuries in Canadian amateur hockey.

    PubMed

    Pashby, T J

    1979-01-01

    Two studies, one retrospective (1972 to 1973) and one prospective (1974 to 1975), CONcerning eye injuries incurred by hockey players were conducted by the Canadian Ophthalmological Society with questionnaires to its members. Responses to the questionnaires were analyzed by age, type of injury, cause (i.e., hockey stick, puck, or other means), and results to visual acuity. The results were also designated by organized or unorganized participation. Almost 300 eye injuries were reported in each study. In the first study, 13.7% of the injured players became legally blind as a result of the injury; in the second study, 16% became legally blind. Organized hockey produced more injuries than unorganized hockey. The majority of the injuries were caused by the hockey stick. The injuries were both intraocular and extraocular. The group of 11- to 15-year olds received the highest number of injuries, and the older age group had the higher incidence of blindness. Studies have led to setting more rigid standards, altering rules of the game, and selecting face protectors for hockey players. Older players who care for their equipment prefer the plastic shield face protectors, and the younger players (who complain of fogging and scratching of the plastic) prefer mesh protectors through which neither the stick nor the puck can penetrate. New high sticking (above the shoulder level) rules were included in the 1976 official rule book for Canadian amateur hockey. PMID:474867

  2. Explosive Model Tarantula 4d/JWL++ Calibration of LX-17

    SciTech Connect

    Souers, P C; Vitello, P A

    2008-09-30

    Tarantula is an explosive kinetic package intended to do detonation, shock initiation, failure, corner-turning with dead zones, gap tests and air gaps in reactive flow hydrocode models. The first, 2007-2008 version with monotonic Q is here run inside JWL++ with square zoning from 40 to 200 zones/cm on ambient LX-17. The model splits the rate behavior in every zone into sections set by the hydrocode pressure, P + Q. As the pressure rises, we pass through the no-reaction, initiation, ramp-up/failure and detonation sections sequentially. We find that the initiation and pure detonation rate constants are largely insensitive to zoning but that the ramp-up/failure rate constant is extremely sensitive. At no time does the model pass every test, but the pressure-based approach generally works. The best values for the ramp/failure region are listed here in Mb units.

  3. Double Shock Experiments and Reactive Flow Modeling on LX-17 to Understand the Reacted Equation of State

    NASA Astrophysics Data System (ADS)

    Vandersall, Kevin; Garcia, Frank; Fried, Laurence; Tarver, Craig

    2013-06-01

    Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as possible future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  4. Double shock experiments and reactive flow modeling on LX-17 to understand the reacted equation of state

    NASA Astrophysics Data System (ADS)

    Vandersall, Kevin S.; Garcia, Frank; Fried, Laurence E.; Tarver, Craig M.

    2014-05-01

    Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments.

  5. Kick Dis Power Puck

    NASA Astrophysics Data System (ADS)

    Carlson, John E.

    2004-03-01

    There is a new toy available that can be used to demonstrate many interesting physics principles. It is called the "Kick Dis Power Puck" and is basically a round plastic hovercraft with a soft cushion material around the perimeter (Fig. 1). It is a product of the Estes Company, which is well known for their model rockets, and is available from advertisers in this journal.1,2 The puck has a diameter of 19.5 cm and comes in two colors, red or green. The two samples I purchased had masses of 307 g and 303 g, respectively. There is a forceful, built-in fan, which is run by a rechargeable battery and powers the puck for about 30 minutes. A 9-V battery charger completes the package, which sells for about 45.

  6. Le Hockey [Hockey]. Teacher's Guide.

    ERIC Educational Resources Information Center

    Balchunas, Martha; Ullmann, Rebecca

    A resource kit for the teaching of French at the intermediate level is represented by a teacher's guide and the duplicating master for a tape transcript. The aim of this module is to make the elementary or secondary school student of French familiar with basic hockey terms in French, and to enable the student to understand hockey games broadcast…

  7. Le Hockey [Hockey]. Teacher's Guide.

    ERIC Educational Resources Information Center

    Balchunas, Martha; Ullmann, Rebecca

    A resource kit for the teaching of French at the intermediate level is represented by a teacher's guide and the duplicating master for a tape transcript. The aim of this module is to make the elementary or secondary school student of French familiar with basic hockey terms in French, and to enable the student to understand hockey games broadcast

  8. Embedded electromagnetic gauge measurements and modeling of shock initiation in the TATB based explosives PBX 9502 and LX-17

    SciTech Connect

    Gustavsen, R. L.; Sheffield, S. A.; Alcon, R. R.; Forbes, J. W.; Tarver, C. M.; Garcia, F.

    2001-01-01

    We have completed a series of shock initiation experiments on PBX 9502 (95 weight % dry aminated TATB explosive, 5 weight % Kel-F 800 binder) and LX-17 (92.% wet aminated TATB, 7.5 % Kel-F 800). These experiments were performed on the gas/gas two stage gun at Los Alamos. Samples were prepared with ten or eleven embedded electromagnetic particle velocity gauges to measure the evolution of the wave leading up to a detonation. Additionally, one to three shock tracker gauges were used to track the position of the shock front with time and determine the point where detonation was achieved. Wave profiles indicate little delay between formation of hot-spots in the shock front and release of hotspot energy. In other words, a great deal of the buildup occurs in the shock front, rather than behind it. Run distances and times to detonation as a function of initial pressure are consistent with published data. The Ignition and Growth model with published parameters for LX-17 replicate the data very well.

  9. Hockey Injuries

    PubMed Central

    Sproule, James R.

    1988-01-01

    Hockey, Canada's national sport, is probably the world's fastest team sport. The nature of the game makes injuries a common occurence. This article reviews the literature on hockey injuries and identifies some of the changing trends over the past 15 years. Severity and incidence of injuries increase with the age and skill level of the player. There are fewer lacerations, eye injuries, and head injuries since helmets and facial protectors have become mandatory in minor hockey. However, there has been an increase in spinal cord injuries. Physicians who provide medical coverage for older adolescent and adult competitive lite hockey players should be proficient at assessment and acute care of patients with life-threatening injuries. PMID:21264029

  10. Formulation and Characterization of LX-17-2 from new FK 800 binder and WA, ATK, and BAE TATBs

    SciTech Connect

    DePiero, S C; Hoffman, D M

    2007-08-03

    Currently LLNL has no Kel-F 800 or wet-aminated TATB reserves for formulation. Although both materials are soon to be commercially available, their synthesis processes have changed and the explosive must be re-evaluated. In 2000 3M phased out the uses of perfluorooctanoyl (C8) derivatives due to environmental persistence and bioaccumulation issues. A C8 derivative was used as an emulsifier for making Kel F-800. In 2001 Kel F-800 was scheduled to be discontinued and the last Kel F-800 run was made in early 2002. LANL ordered 2M$ worth of Kel-F 800 for reserves and Pantex purchased several hundred pounds to satisfy mock needs. After four years, 3M has decided to introduce a Kel-F 800-like polymer based on a new emulsifier using the same chlorotrifluoroethylene and vinylidene fluoride monomers and emulsion polymerization process. They have produced 3 batches and claim the 'new' FK-800 is indistinguishable from the 'old' Kel-F 800 in any of their testing parameters. In June-July 2006 3M scaled up a batch of about 800 pounds and have test quantities available. We have samples of the new FK-800 for evaluation. Neither wet nor dry-aminated TATB has been synthesized in the US in any significant quantity since about 1985 and significant quantities of LX-17-1 has not been formulated since about 1990. Over the last few years as part of a DOD MANTECH, ATK Thiokol and BAE Holston Army Ammunition Plant (HAAP) have produced moderate quantities of TATB ({approx}5 kg batches) with plans to scale up for DOD applications. Thiokol TATB is polycrystalline with an average particle size of about 40 m (similar to WA TATB) but HAAP TATB is only 5-6 {micro}m (similar to ultrafine). We have obtained small quantities of these materials for evaluation. The project (1) compares new FK-800 with old Kel-F 800 and FK-800 lots currently available at LLNL, (2) compares and characterizes new TATB with old TATB, (3) formulates new FK-800 with wet-aminated TATB and new TATBs in according to HAAP slurry coating procedure into LX-17-2, and (4) evaluates the mechanical and detonation performance characteristics of this insensitive high explosive (IHE). Priorities are to prove that these new materials can be formulated, pressed to density and machined; and that they contain no impurities which might cause compatibility issues. Since 3M, LANL, Pantex and AWE are currently evaluating the new FK-800, we plan to share data rather than repeating their work. Our effort is described.

  11. Hockey, iPads, and Projectile Motion in a Physics Classroom

    ERIC Educational Resources Information Center

    Hechter, Richard P.

    2013-01-01

    With the increased availability of modern technology and handheld probeware for classrooms, the iPad and the Video Physics application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics…

  12. Hockey, iPads, and Projectile Motion in a Physics Classroom

    ERIC Educational Resources Information Center

    Hechter, Richard P.

    2013-01-01

    With the increased availability of modern technology and handheld probeware for classrooms, the iPad and the Video Physics application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics

  13. Hockey, iPads, and Projectile Motion in a Physics Classroom

    NASA Astrophysics Data System (ADS)

    Hechter, Richard P.

    2013-09-01

    With the increased availability of modern technology and handheld probeware for classrooms, the iPad and the Video Physics2 application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics phenomena using modern technologies to complement theoretical plots. This activity acknowledges hockey players' implicit understanding of the launch angle and initial velocity of a saucer pass as basic projectile motion while engaging students in authentic physics-based problem solving.

  14. Neurologic injuries in hockey.

    PubMed

    Wennberg, Richard A; Cohen, Howard B; Walker, Stephanie R

    2008-02-01

    Ice hockey is a fast contact sport played on an ice surface enclosed by rigid boards. There is an intrinsic risk for injury in hockey, with many injuries potentially affecting the nervous system. This article provides an overview of neurologic injuries occurring in hockey as reported in the scientific literature. Among all injuries, a small but real risk for catastrophic cervical spinal cord injury and a high incidence of concussion emerge as the two most important neurologic issues. PMID:18295093

  15. Concussion in ice hockey.

    PubMed

    Bonfield, Christopher M; Wecht, Daniel A; Lunsford, L Dade

    2014-01-01

    Ice hockey is an aggressive and fast-paced sport which has a high risk of injury, concussions in particular. Although serious head injury has been recognized for nearly 50 years, an increase in mainstream media attention in recent years has led to unprecedented public awareness. As a result, the National Hockey League (NHL) and other professional leagues around the world have initiated concussion protocols in order to better prevent, recognize, and treat concussions. With over 1,000,000 youth hockey participants in Canada and the USA combined, concussion is an issue that reaches beyond the professional level. In this report we review the incidence, evaluation, treatment, return-to-play protocol, and prevention efforts related to concussion in ice hockey. PMID:24923401

  16. Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique

    SciTech Connect

    Hare, D E; Chandler, J B; Compton, S M; Garza, R G; Grimsley, D A; Hernandez, A; Villafana, R J; Wade, J T; Weber, S R; Wong, B M; Souers, P C

    2008-01-16

    The detailed history of the shock/detonation wave propagation after crossing a room-temperature-room-pressure (RTP) air gap between a 25.4 mm diameter LX-17 donor column and a 25.4 mm diameter by 25.4 mm long LX-17 acceptor pellet is investigated for three different gap widths (3.07, 2.08, and 0.00 mm) using the Embedded Fiber Optic (EFO) technique. The 2.08 mm gap propagated and the 3.07 mm gap failed and this can be seen clearly and unambiguously in the EFO data even though the 25.4 mm-long acceptor pellet would be considered quite short for a determination by more traditional means such as pins.

  17. A Hockey Hero

    ERIC Educational Resources Information Center

    Bolduc, Matt

    2009-01-01

    In this article, the author shares the story of Will Poulos, a hockey player who has developmental and physical disabilities (mild mental retardation and left cerebral palsy). Will has overcome tremendous obstacles in his life. He was born at 28 weeks in 1986 at three pounds, one ounce, and 19 inches long. He was very sick; his odds for survival…

  18. A Hockey Hero

    ERIC Educational Resources Information Center

    Bolduc, Matt

    2009-01-01

    In this article, the author shares the story of Will Poulos, a hockey player who has developmental and physical disabilities (mild mental retardation and left cerebral palsy). Will has overcome tremendous obstacles in his life. He was born at 28 weeks in 1986 at three pounds, one ounce, and 19 inches long. He was very sick; his odds for survival

  19. Isolated scapula fracture: Ice hockey player without trauma

    PubMed Central

    Memişoğlu, Serdar; Yılmaz, Barış; Aktaş, Erdem; Kömür, Baran

    2015-01-01

    Introduction Scapular fractures are generally occur from in high-energy traumas and are associated with a high incidence of morbidity and mortality. Presentation of case We present an unusual scapular fracture that occurred with a rare mechanism. A 23-year-old male patient who led an active sports life for 10 years and played ice hockey for the last 5 years. In a competition, he felt a sudden pain in his right scapula after hit the puck. He did not experience any direct trauma to his shoulder and there was no evidence of any pathological fracture. The fracture was isolated in the scapular body and it was classified as type 4, according to Hardegger classification. The was patient immobilized with a Velpau bandage for three weeks and then treated with physiotherapy for shoulder rehabilitation. Discussion The fracture mechanism was likely a disharmonius contracture of the agonist and antagonist muscles of the shoulder joint while hitting the puck. Conclusion Scapular fractures are generally seen along with other injuries, but in this case we wanted to emphasize that care has to been taken to diagnose an isolated scapular fracture while assessing shoulder pain. PMID:26587232

  20. Nutrition and ice hockey performance.

    PubMed

    Houston, M E

    1979-03-01

    Muscle glycogen is a major fuel for ice hockey. About 60% of the muscle glycogen in quadriceps muscle is utilized during a single game. When hockey games are played on successive days, studies reveal that muscle glycogen utilized during the second game is less than that of the first game. The diet of seven professional hockey players was studied for one week during the playing season to determine whether food selection could pose a problem for hockey performance. The data reveal that most players have a high protein intake, but that vegetables and fruit intakes were low. The problem of fuel supply for young hockey players is examined during tournament situations where up to three or more games may be played in a single day. PMID:498411

  1. Injuries in men's international ice hockey: a 7-year study of the International Ice Hockey Federation Adult World Championship Tournaments and Olympic Winter Games

    PubMed Central

    Tuominen, Markku; Stuart, Michael J; Aubry, Mark; Kannus, Pekka; Parkkari, Jari

    2015-01-01

    Background Information on ice hockey injuries at the international level is very limited. The aim of the study was to analyse the incidence, type, mechanism and severity of ice hockey injuries in men's international ice hockey tournaments. Methods All the injuries in men's International Ice Hockey Federation World Championship tournaments over a 7-year period were analysed using a strict definition of injury, standardised reporting strategies and an injury diagnosis made by a team physician. Results 528 injuries were recorded in games resulting in an injury rate of 14.2 per 1000 player-games (52.1/1000 player-game hours). Additionally, 27 injuries occurred during practice. For WC A-pool Tournaments and Olympic Winter Games (OWG) the injury rate was 16.3/1000 player-games (59.6/1000 player-game hours). Body checking, and stick and puck contact caused 60.7% of the injuries. The most common types of injuries were lacerations, sprains, contusions and fractures. A laceration was the most common facial injury and was typically caused by a stick. The knee was the most frequently injured part of the lower body and the shoulder was the most common site of an upper body injury. Arenas with flexible boards and glass reduced the risk of injury by 29% (IRR 0.71, (95% CI 0.56 to 0.91)). Conclusions The incidence of injury during international ice hockey competition is relatively high. Arena characteristics, such as flexible boards and glass, appeared to reduce the risk of injury. PMID:25293341

  2. Thermopower Puck for Measurement of Thermodynamic Properties

    NASA Astrophysics Data System (ADS)

    Vargas, Andres; Fukuda, Ryan; Soliz, Nicholas; Ho, Pei-Chun

    2014-03-01

    A thermopower puck was created in order to measure the thermoelectric power and thermal conductance of strongly correlated electron materials from 10K to 300K. The puck consists of a 2k Ω resistivity heater and 2 thermometers. The heater is connected to the top of the sample and applies heat until thermal equilibrium is reached. This creates a temperature gradient across the sample and is read by the 2 thermometers, one reading the hotter temperature and the other reading the colder temperature. The wire that is used as the thermal anchor for the high temperature thermometer, which is electrically isolated from thermometer, is also used as one of the leads to measure the thermal voltage produced across the sample. To calibrate the measurement probe, the thermoelectric power and thermal conductance of a nickel sample, which was purchased from Quantum Design, was measured. The data obtained qualitatively agrees with the literature data provided to us by Quantum Design. For future work, we will be using the measurement probe to investigate the thermodynamic properties of intermetallic compounds. Research at CSU-Fresno is supported by NSF DMR-1104544. Felipe Vargas is also supported by Undergraduate Research Grant at CSU Fresno.

  3. Concussions in Ice Hockey.

    PubMed

    Parizek, Allison; Ferraro, F Richard

    2016-01-01

    This literature review will summarize, compare, and evaluate the reviewed studies addressing and investigating the relationship between concussion and the sports of hockey. We will accomplish this by identifying prevalence rates, recognizing common mechanisms of causation, describing and discussing prevention and care, and summarizing the results to provide implications for further studies. We conclude by indicating the important mental health issues as well as potentially severe and long-lasting impact concussions can and do have on those that receive them as well as on the friends and families of those who sustain a concussion. PMID:26745166

  4. Eye injuries in Canadian hockey.

    PubMed Central

    Pashby, T. J.; Pashby, R. C.; Chisholm, L. D.; Crawford, J. S.

    1975-01-01

    Increasing public concern led the Canadian Ophthalmological Society, in January 1974, to form a committee to study the incidence, types and causes of hockey eye injuries and to devise means of reducing such injuries. Retrospective and current studies were undertaken, and face protectors were tested. In both pilot studies, sticks were the commonest cause and the highest number of eye injuries was in players 11-15 years old. An average of 15% of all injured eyes were rendered legally blind. Cooperation with hockey authorities has resulted in changed rules and their sticter enforcement, and formulation of standards for face protection approved by the Canadian Standards Association. In this interim report the committee recommends that all amateur hockey players wear eye protectors and urges ophthalmologists to participate in efforts to improve the design of protective equipment. Images FIG. 1 PMID:1181024

  5. Massachusetts Special Olympics Poly Hockey.

    ERIC Educational Resources Information Center

    Morrissey, Jim

    Poly Hockey is featured in this manual of instructions for coaches and teachers to use with mentally retarded boys and girls of all ages and ability levels. It is noted that the sport has been supported by the Board of Directors of the Special Olympics and has been used in Massachusetts for over 7 years. Explained is use of the game indoors, and…

  6. Physiology applied to field hockey.

    PubMed

    Reilly, T; Borrie, A

    1992-07-01

    Field hockey is a sport with a long history that has undergone quite rapid and radical change within the past decade. The advent of the synthetic playing surface has changed the technical, tactical and physiological requirements of the game at all levels, but in particular at the elite level. In order to cope with the technical evolution within the game, the hockey player has also had to develop physiologically to meet the physical standards required at elite levels. Analysis of the physiological cost and energy expenditure of playing hockey has placed it in the category of 'heavy exercise', with reported VO2 values during a game of 2.26 L/min. Energy expenditure has been estimated to range from 36 to 50 kJ/min. Physiological profiling of female hockey players has shown that somatotype tends towards 3.5/4.0/2.5. Figures for percentage body fat in female players range from 16 to 26%. Anaerobic power output has been shown to compare favourably with other groups of sportswomen and has also been shown to be a discriminating factor between elite and county level female players. Aerobic power amongst female players has been shown to range from 45 to 59 ml/kg/min. The reported somatotypes of male hockey players have shown considerable variation but there seems to be a trend away from ectomorphy towards mesomorphy. Anaerobic power output in male players has been shown to be the same as that of soccer players and better than other sports, e.g. basketball and also higher than reference norms. The range of aerobic power reported in the literature is 48 to 65 ml/kg/min and it would appear that an aerobic power in excess of 60 ml/kg/min is required for elite level play. The physical strain of hockey play has been shown to be considerable, in particular with respect to spinal shrinkage. There is a greater injury risk inherent in playing on synthetic surfaces than on grass. PMID:1641540

  7. Visual Attentional Orienting in Developing Hockey Players.

    ERIC Educational Resources Information Center

    Enns, James T.; Richards, James C.

    1997-01-01

    Covert visual orienting was measured in 13 twelve-year-old and 11 fifteen-year-old hockey players and in 13 college students with no hockey training. Found that high-skill 15-year-olds were better able than all other groups to take advantage of the general alerting effect produced by the sudden onset of a cue. (MDM)

  8. Field Hockey-Lacrosse Guide. June 1974-June 1976.

    ERIC Educational Resources Information Center

    Ramser, Frances, Ed.; Bixler, Agnes, Ed.

    This guide is a collection of essays by various authors on field hockey and lacrosse. There is a separate section for each sport. The topics covered in the field hockey section include half-time coaching, visual aids, umpiring techniques and ratings, goalkeeper training, experimental field hockey rules, and the code of rules for the game of hockey

  9. Evaluation of cricket helmet performance and comparison with baseball and ice hockey helmets

    PubMed Central

    McIntosh, A; Janda, D

    2003-01-01

    Background: Protective helmets in sport are important for reducing the risk of head and facial injury. In cricket and other sports with projectiles, national test standards control the minimum helmet performance. However, there are few field data showing if helmets are effective in reducing head injury. Objectives: (a) To examine the performance of cricket helmets in laboratory tests; (b) to examine performance with regard to test standards, game hazards, and helmet construction; (c) to compare and contrast these findings with baseball and ice hockey helmets. Methods: Impact tests were conducted on a selection of helmet models: five cricket, two baseball, and two ice hockey. Ball to helmet impacts at speeds of 19, 27, 36, and 45 m/s were produced using an air cannon and a Hybrid III dummy headform and neck unit. Free fall drop tests with a rigid headform on to a selection of anvils (flat rigid, flat deformable, and hemispherical rigid) were conducted. Resultant headform acceleration was measured and compared between tests. Results: At the lower speed impacts, all helmets produced a good reduction in headform acceleration, and thus injury risk. At the higher speed impacts, the effectiveness was less. For example, the mean maximum headform accelerations for all cricket helmets at each speed were: 67, 160, 316, and 438 g for 19, 27, 36, and 45 m/s ball speeds respectively. Drop tests on to a hemispherical anvil produced the highest accelerations. The variation in performance increased as the magnitude of the impact energy increased, in both types of testing. Conclusions: The test method used for baseball helmets in which the projectile is fired at the helmet may be superior to helmet drop tests. Cricket helmet performance is satisfactory for low speed impacts, but not for impacts at higher, more realistic, speeds. Baseball and ice hockey helmets offer slightly better relative and absolute performance at the 27 m/s ball and puck impacts. PMID:12893718

  10. Maintaining hydration with a carbohydrate-electrolyte solution improves performance, thermoregulation, and fatigue during an ice hockey scrimmage.

    PubMed

    Linseman, Mark E; Palmer, Matthew S; Sprenger, Heather M; Spriet, Lawrence L

    2014-11-01

    Research in "stop-and-go" sports has demonstrated that carbohydrate ingestion improves performance and fatigue, and that dehydration of ?1.5%-2% body mass (BM) loss results in decreased performance, increased fatigue, and increased core temperature. The purpose of this investigation was to assess the physiological, performance, and fatigue-related effects of maintaining hydration with a carbohydrate-electrolyte solution (CES) versus dehydrating by ?2% BM (no fluid; NF) during a 70-min ice hockey scrimmage. Skilled male hockey players (n = 14; age, 21.3 0.2 years; BM, 80.1 2.5 kg; height, 182.0 1.2 cm) volunteered for the study. Subjects lost 1.94% 0.1% BM in NF, and 0.12% 0.1% BM in CES. Core temperature (Tc) throughout the scrimmage (10-50 min) and peak Tc (CES: 38.69 0.10 vs. NF: 38.92 0.11 C; p < 0.05) were significantly reduced in CES compared with NF. Players in CES had increased mean skating speed and time at high effort between 30-50 min of the scrimmage. They also committed fewer puck turnovers and completed a higher percentage of passes in the last 20 min of play compared with NF. Postscrimmage shuttle skating performance was improved in CES versus NF and fatigue was lower following the CES trial. The results indicated that ingesting a CES to maintain BM throughout a 70-min hockey scrimmage resulted in improved hockey performance and thermoregulation, and decreased fatigue as compared with drinking no fluid and dehydrating by ?2%. PMID:25061764

  11. Hockey Stats: Data Collection on Ice.

    ERIC Educational Resources Information Center

    Harris, Joanne

    2002-01-01

    Part of a series exploring how mathematics is used in the workplace. Software developers and statisticians record data of hockey games and players using statistics accessible to middle school students. (MM)

  12. Shoulder injuries in ice hockey.

    PubMed

    Finke, R C; Goodwin Gerberich, S; Madden, M; Funk, S; Murray, K; Priest, J D; Aamoth, G M

    1988-01-01

    Financial support for this study was provided by: the Hubbard Foundation, St. Paul, MN; Institute for Athletic Medicine, Fairview Community Hospitals, Minneapolis, MN; Institute for Athletic Medicine of John C. Lincoln Hospital. Phoenix, AZ; The Mendon Schutt Foundation, Minneapolis; Minnesota State High School League, Anoka, MN; University of Minnesota Computer Center; multiple private donations. A study of shoulder injuries incurred by high school ice hockey players was conducted for the 1982-1983 and 1983-1984 competitive seasons. Data from 480 players (73%), who competed on 12 teams within a 30 mile radius, were included in the analysis. Among these players, shoulder injuries accounted for a rate of 9.4 injuries per 100 players; separation of the acromioclavicular joint was the most common injury. Although 39% of the reported injuries were of mild severity, 44% were moderate in severity, and 18% were major in severity; moreover, 59% of the injured players reported residual persistent symptoms. Of the total injuries, 88% occurred in games or under game-type conditions. The greatest proportion of injuries occurred to players engaged in play in the forward position while in the offensive zone. Over 54% of the injuries were caused by contact with the boards surrounding the ice surface and, reportedly, 43% of the injuries were associated with illegal activities. Based on the study findings, strategies for injury prevention include the following: consideration of techniques of coaching and of play; enforcement of the current rules to decrease the number of injuries related to illegal activities; research relevant to board design and materials to determine if a more yielding barrier can be placed around the playing surface; and utilization of the latest equipment, incorporating unique design and materials, that facilitates dissipation of forces. In addition, there is a need for further comprehensive research efforts relevant to ice hockey injuries that can enable the identification of other risk factors so that prevention and control of injuries can be managed more readily.J Orthop Sports Phys Ther 1988;10(2):54-58. PMID:18796975

  13. Ice hockey: a team physician's perspective.

    PubMed

    Moslener, Matthew D; Wadsworth, L Tyler

    2010-01-01

    Ice hockey is an exciting sport that is growing in popularity in the United States. Injuries are a common part of the sport, with more injuries occurring in games compared with practice. Higher levels of competition have been shown to correlate with increased frequency of injury. Most frequently, injuries occur to the face, head, and neck, including concussions, contusions, lacerations, and dental injury. Lower extremity injuries include medial collateral ligament injury, meniscus tear, and high ankle sprains. Upper extremity injuries include acromioclavicular joint injury, glenohumeral dislocation, and various contusions and sprains. Groin and lower abdominal strains also are common. Women's hockey participation is increasing, with data that suggest injuries similar to those seen in men's hockey. PMID:20463495

  14. Injuries in women's ice hockey: special considerations.

    PubMed

    Abbott, Kristin

    2014-01-01

    Ice hockey is a popular collision sport with a growing number of female athletes participating each year. As participation among girls and women continues to increase, it will be important to recognize common injuries occurring during women's games. Despite difference in the rules that prohibit body checking in women's and girls' games, injury profiles are similar to those of their male counterparts. Concussions, contusions, acromioclavicular joint injuries, ligamentous knee injuries, and muscle strains occur during women's ice hockey games, with groin strains accounting for the most common practice injury. This article will review both injury rates and common injuries occurring in women's ice hockey, with a focus on the observed concussion rate and groin injuries. PMID:25391093

  15. Explanatory style among elite ice hockey athletes.

    PubMed

    Davis, H; Zaichkowsky, L

    1998-12-01

    Mentally tough' athletes show resilience and an ability to compete during adverse conditions. The present study investigated mental toughness and assessed causal explanations for positive and negative reactions to imagined events using Seligman's Attributional Style Questionnaire. Pessimistic Explanatory style on this scale is a risk factor for negative affect and behavior following negative events. 38 elite athletes in ice hockey were rated for mental toughness by the National Hockey League's scouts on consensually derived criteria. The comparison of players above and below the median split on mental toughness showed composite explanations for negative events that were more internal, stable and global for players above the median. Contrary to predictions, these results suggest that a Pessimistic Explanatory style may benefit hockey performance. PMID:9885080

  16. Body Checking in Pee Wee Hockey.

    ERIC Educational Resources Information Center

    Roy, Michel-Andre; And Others

    1989-01-01

    The results of 2 studies determining the effects of body checking in Pee Wee hockey indicate variability in player size and strength is reason to avoid this practice. In leagues allowing body checking, 55 percent of all injuries and greater frequency of serious injury were a result of body contact. (SM)

  17. The Open Geospatial Consortium PUCK Standard: Building Sensor Networks with Self-Describing Instruments

    NASA Astrophysics Data System (ADS)

    O'Reilly, T. C.; Broering, A.; del Rio, J.; Headley, K. L.; Toma, D.; Bermudez, L. E.; Edgington, D.; Fredericks, J.; Manuel, A.

    2012-12-01

    Sensor technology is rapidly advancing, enabling smaller and cheaper instruments to monitor Earth's environment. It is expected that many more kinds and quantities of networked environmental sensors will be deployed in coming years. Knowledge of each instrument's command protocol is required to operate and acquire data from the network. Making sense of these data streams to create an integrated picture of environmental conditions requires that each instrument's data and metadata be accurately processed and that "suspect" data be flagged. Use of standards to operate an instrument and retrieve and describe its data generally simplifies instrument software development, integration, operation and data processing. The Open Geospatial Consortium (OGC) PUCK protocol enables instruments that describe themselves in a standard way. OGC PUCK defines a small "data sheet" that describes key instrument characteristics, and a standard protocol to retrieve the data sheet from the device itself. Data sheet fields include a universal serial number that is unique across all PUCK-compliant instruments. Other fields identify the instrument manufacturer and model. In addition to the data sheet, the instrument may also provide a "PUCK payload" which can contain additional descriptive information (e.g. a SensorML document or IEEE 1451 TEDS), as well as actual instrument "driver" code. Computers on the sensor network can use PUCK protocol to retrieve this information from installed instruments and utilize it appropriately, e.g. to automatically identify, configure and operate the instruments, and acquire and process their data. The protocol is defined for instruments with an RS232 or Ethernet interface. OGC members recently voted to adopt PUCK as a component of the OGC's Sensor Web Enablement (SWE) standards. The protocol is also supported by a consortium of hydrographic instrument manufacturers and has been implemented by several of them (https://sites.google.com/site/soscsite/). Thus far PUCK has been deployed on oceanographic observatories in North America and Europe, and is generally applicable to environmental sensor networks. As an example we describe how PUCK can be used with other established and emerging OGC SWE standards to simplify configuration and operation of environmental sensor networks, and to automate assessment and processing of the sensor data. The PUCK specification is free of charge and can be downloaded along with tools to implement and use the standard from http://www.opengeospatial.org/standards/puck.

  18. Hockey STAR: A Methodology for Assessing the Biomechanical Performance of Hockey Helmets.

    PubMed

    Rowson, Bethany; Rowson, Steven; Duma, Stefan M

    2015-10-01

    Optimizing the protective capabilities of helmets is one of several methods of reducing brain injury risk in sports. This paper presents the experimental and analytical development of a hockey helmet evaluation methodology. The Summation of Tests for the Analysis of Risk (STAR) formula combines head impact exposure with brain injury probability over the broad range of 227 head impacts that a hockey player is likely to experience during one season. These impact exposure data are mapped to laboratory testing parameters using a series of 12 impact conditions comprised of three energy levels and four head impact locations, which include centric and non-centric directions of force. Injury risk is determined using a multivariate injury risk function that incorporates both linear and rotational head acceleration measurements. All testing parameters are presented along with exemplar helmet test data. The Hockey STAR methodology provides a scientific framework for manufacturers to optimize hockey helmet design for injury risk reduction, as well as providing consumers with a meaningful metric to assess the relative performance of hockey helmets. PMID:25822907

  19. Hockey-stick steam generator for LMFBR

    SciTech Connect

    Hallinan, G.J.; Svedlund, P.E.

    1981-01-01

    This paper presents the criteria and evaluation leading to the selection of the Hockey Stick Steam Generator Concept and subsequent development of that concept for LMFBR application. The selection process and development of the Modular Steam Generator (MSG) is discussed, including the extensive test programs that culminated in the manufacture and test of a 35 MW(t) Steam Generator. The design of the CRBRP Steam Generator is described, emphasizing the current status and a review of the critical structural areas. CRBRP steam generator development tests are evaluated, with a discussion of test objectives and rating of the usefulness of test results to the CRBRP prototype design. Manufacturing experience and status of the CRBRP prototype and plant units is covered. The scaleup of the Hockey Stick concept to large commercial plant application is presented, with an evaluation of scaleup limitations, transient effects, and system design implications.

  20. Injury potential in modern ice hockey.

    PubMed

    Sim, F H; Chao, E Y

    1978-01-01

    The majority of the damaging forces to the soft tissue, bone, and articular joint structures of modern hockey players during the energetic activities involved in the game are attributable to impact action during high-speed motion. In addition, non-contact musculoligamentous injuries are common because of the complex forces that are involved. The injury potential of this sport is assessed indirectly from the force and motion involved. The experimental method of measuring the kinematic motion and the impact forces inherent to the sport are presented. Although hockey is a fast and furious game with high injury potential, fortunately the number of serious injuries is not as great as one might expect. PMID:736199

  1. Hockey sticks, principal components, and spurious significance

    NASA Astrophysics Data System (ADS)

    McIntyre, Stephen; McKitrick, Ross

    2005-02-01

    The ``hockey stick'' shaped temperature reconstruction of Mann et al. (1998, 1999) has been widely applied. However it has not been previously noted in print that, prior to their principal components (PCs) analysis on tree ring networks, they carried out an unusual data transformation which strongly affects the resulting PCs. Their method, when tested on persistent red noise, nearly always produces a hockey stick shaped first principal component (PC1) and overstates the first eigenvalue. In the controversial 15th century period, the MBH98 method effectively selects only one species (bristlecone pine) into the critical North American PC1, making it implausible to describe it as the ``dominant pattern of variance''. Through Monte Carlo analysis, we show that MBH98 benchmarks for significance of the Reduction of Error (RE) statistic are substantially under-stated and, using a range of cross-validation statistics, we show that the MBH98 15th century reconstruction lacks statistical significance.

  2. Miniature Videoprobe Hockey Stick Delivery System

    SciTech Connect

    Hale, Lester R.; McMurry, Kyle M.

    1998-06-18

    The present invention is a miniature videoprobe system having a probe termination box, a strong back, and a videoprobe housing. The videoprobe system is able to obtain images from a restricted space at least as small as 0.125 inches while producing a high quality image. The strong back has a hockey stick shape with the probe termination box connecting to the top of the handle-like portion of the hockey stick and the videoprobe housing attaching to the opposite end or nose of the hockey stick shape. The videoprobe housing has a roughly arrowhead shape with two thin steel plates sandwiching the internal components there between. The internal components are connected in series to allow for a minor dimension of the videoprobe housing of 0.110 inches. The internal components include an optics train, a CCD chip, and an electronics package. An electrical signal is transmitted from the electronics package through wiring within an internal channel of the strong back to the probe termination box. The strong back has milled into it multiple internal channels for facilitating the transfer of information, items, or devices between the probe termination box and the videoprobe housing.

  3. Fathers' Career Aspirations for Sons in Competitive Ice Hockey Programs.

    ERIC Educational Resources Information Center

    Berlage, Gai Ingham

    A survey was made of 107 fathers of boys aged 11 and 12 competing in the Pee Wee Level Division III of the Connecticut State Ice Hockey Tournament. The questionnaire was designed to examine the career aspirations of the fathers for their sons in ice hockey, and to determine their attitudes toward their son's participation in the sport as it

  4. The Ice Hockey Injury: A Case Study in Physiology

    ERIC Educational Resources Information Center

    Stephens, Phil

    2004-01-01

    A high school hockey team is playing the last of three games in one day. The game gets rough, and the star player is slammed against the boards. Injured, he is escorted off the ice. This case follows his health as it deteriorates over the next several hours. Students are presented with the hockey player's symptoms, and they use their knowledge of

  5. 11. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, Detroit, Michigan). GROUNDBREAKING FOR ADDITION, JUNE 23, 1965. Left Sid Abel, Genral Manager of the Detroit Hockey Club Center - Jerome Cavanaugh, Mayor, City of Detroit Right - Nick Landis, General Manager of the Olympia Stadium - Olympia Arena, 5920 Grand River Avenue, Detroit, Wayne County, MI

  6. Bodychecking Rules and Concussion in Elite Hockey

    PubMed Central

    Donaldson, Laura; Asbridge, Mark; Cusimano, Michael D.

    2013-01-01

    Athletes participating in contact sports such as ice hockey are exposed to a high risk of suffering a concussion. We determined whether recent rule changes regulating contact to the head introduced in 201011 and 201112 have been effective in reducing the incidence of concussion in the National Hockey League (NHL). A league with a longstanding ban on hits contacting the head, the Ontario Hockey League (OHL), was also studied. A retrospective study of NHL and OHL games for the 200910 to 201112 seasons was performed using official game records and team injury reports in addition to other media sources. Concussion incidence over the 3 seasons analyzed was 5.23 per 100 NHL regular season games and 5.05 per 100 OHL regular season games (IRR 1.04; 95% CI 1.01, 1.50). When injuries described as concussion-like or suspicious of concussion were included, incidences rose to 8.8 and 7.1 per 100 games respectively (IRR 1.23; 95% CI 0.81, 1.32). The number of NHL concussions or suspected concussions was lower in 200910 than in 201011 (IRR 0.61; 95% CI 0.45, 0.83), but did not increase from 201011 to 201112 (IRR 1.05; 95% CI 0.80, 1.38). 64.2% of NHL concussions were caused by bodychecking, and only 28.4% of concussions and 36.8% of suspected concussions were caused by illegal incidents. We conclude that rules regulating bodychecking to the head did not reduce the number of players suffering concussions during NHL regular season play and that further changes or stricter enforcement of existing rules may be required to minimize the risk of players suffering these injuries. PMID:23874888

  7. Bodychecking rules and concussion in elite hockey.

    PubMed

    Donaldson, Laura; Asbridge, Mark; Cusimano, Michael D

    2013-01-01

    Athletes participating in contact sports such as ice hockey are exposed to a high risk of suffering a concussion. We determined whether recent rule changes regulating contact to the head introduced in 2010-11 and 2011-12 have been effective in reducing the incidence of concussion in the National Hockey League (NHL). A league with a longstanding ban on hits contacting the head, the Ontario Hockey League (OHL), was also studied. A retrospective study of NHL and OHL games for the 2009-10 to 2011-12 seasons was performed using official game records and team injury reports in addition to other media sources. Concussion incidence over the 3 seasons analyzed was 5.23 per 100 NHL regular season games and 5.05 per 100 OHL regular season games (IRR 1.04; 95% CI 1.01, 1.50). When injuries described as concussion-like or suspicious of concussion were included, incidences rose to 8.8 and 7.1 per 100 games respectively (IRR 1.23; 95% CI 0.81, 1.32). The number of NHL concussions or suspected concussions was lower in 2009-10 than in 2010-11 (IRR 0.61; 95% CI 0.45, 0.83), but did not increase from 2010-11 to 2011-12 (IRR 1.05; 95% CI 0.80, 1.38). 64.2% of NHL concussions were caused by bodychecking, and only 28.4% of concussions and 36.8% of suspected concussions were caused by illegal incidents. We conclude that rules regulating bodychecking to the head did not reduce the number of players suffering concussions during NHL regular season play and that further changes or stricter enforcement of existing rules may be required to minimize the risk of players suffering these injuries. PMID:23874888

  8. International Toys in Space: Hockey - Duration: 2 minutes, 12 seconds.

    NASA Video Gallery

    Cosmonauts Sergi Treschev and Valery Korzun discover ways to adapt the game of hockey while trying to overcome the challenges of playing the game in microgravity. Astronaut Peggy Whitson narrates t...

  9. Illegal Hits Play Big Role in Youth Ice Hockey Concussions

    MedlinePLUS

    ... occur when players break the rules of the game, a new study finds. While the concussion rates ... providing medical assistance, not only during ice hockey games, but also during practices, where more concussions occurred ...

  10. 12. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, Detroit, Michigan). CONSTRUCTION OF BUILDING ADDITION, 1965, LOOKING WEST. - Olympia Arena, 5920 Grand River Avenue, Detroit, Wayne County, MI

  11. 14. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Photocopy of Photograph (Courtesy of the Detroit Hockey Club, Detroit, Michigan). AERIAL VIEW OF OLYMPIA ARENA, LOOKING NORTH, FEBRUARY 9, 1969. - Olympia Arena, 5920 Grand River Avenue, Detroit, Wayne County, MI

  12. Personal food systems of male college hockey players.

    PubMed

    Smart, L R; Bisogni, C A

    2001-08-01

    This study sought to improve the understanding of processes involved in food choice and dietary change by examining how members of a college men's ice hockey team experienced the multiple factors influencing their food choices. The study employed a theory-guided, grounded-theory approach, participant observation, and open-ended interviews with ten team members. Field notes and transcripts were analysed using the constant comparative method. Going to college and playing hockey involved adjusting to new food and athletic environments, increased personal responsibility for food choices, and new meanings for food and eating. Players viewed hockey, health, and taste as major determinants of their food practices. Hockey meant structured schedules, a social network, and performance expectations. Health meant "feeling good" for hockey, having a lean body composition, and a desirable body image. Low-fat foods were viewed generally as healthy, but as not providing taste satisfaction or reward. Players' food practices cycled through four phases over the year according to the changing meanings and importance of hockey, health, and taste. The findings advance the concept of personal food system to represent the way that a person constructs the options, barriers, trade-offs, rules, and routines in food choice in response to how s/he views his/her relationships with food and the environment. PMID:11562158

  13. Procedure for the analysis of RX-03-EJ (LX-17)

    SciTech Connect

    Selig, W.; Crossman, G.L.; Waggoner, M.C.

    1981-05-01

    An analytical procedure is described for the explosive RX-03-EJ with the nominal composition of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) 55 to 83%, polytrifluorochloroethylene (Kel-F800) 4 to 7% and aluminum 20 to 40%. Approximately 1 gram of the explosive is weighed, treated with concentrated nitric acid and refluxed to dissolve all of the aluminum and TATB. After dissolution, the mixture is cooled, filtered in a crucible and the residue (Kel-F) is weighed after drying. Aluminum in the filtrate is determined by taking an aliquot and boiling off the nitric acid unitl almost dry. The residue is then dissolved in distilled water and an excess of EDTA is added which is back-titrated with a zinc solution using xylenol orange as the indicator. The amount of aluminum is obtained by EDTA titration multiplied by the dilution factor and TATB is calculated by difference.

  14. Automatic acquisition of motion trajectories: tracking hockey players

    NASA Astrophysics Data System (ADS)

    Okuma, Kenji; Little, James J.; Lowe, David

    2003-12-01

    Computer systems that have the capability of analyzing complex and dynamic scenes play an essential role in video annotation. Scenes can be complex in such a way that there are many cluttered objects with different colors, shapes and sizes, and can be dynamic with multiple interacting moving objects and a constantly changing background. In reality, there are many scenes that are complex, dynamic, and challenging enough for computers to describe. These scenes include games of sports, air traffic, car traffic, street intersections, and cloud transformations. Our research is about the challenge of inventing a descriptive computer system that analyzes scenes of hockey games where multiple moving players interact with each other on a constantly moving background due to camera motions. Ultimately, such a computer system should be able to acquire reliable data by extracting the players" motion as their trajectories, querying them by analyzing the descriptive information of data, and predict the motions of some hockey players based on the result of the query. Among these three major aspects of the system, we primarily focus on visual information of the scenes, that is, how to automatically acquire motion trajectories of hockey players from video. More accurately, we automatically analyze the hockey scenes by estimating parameters (i.e., pan, tilt, and zoom) of the broadcast cameras, tracking hockey players in those scenes, and constructing a visual description of the data by displaying trajectories of those players. Many technical problems in vision such as fast and unpredictable players' motions and rapid camera motions make our challenge worth tackling. To the best of our knowledge, there have not been any automatic video annotation systems for hockey developed in the past. Although there are many obstacles to overcome, our efforts and accomplishments would hopefully establish the infrastructure of the automatic hockey annotation system and become a milestone for research in automatic video annotation in this domain.

  15. Gender, Sport, and the Construction of Community: A Case Study from Women's Ice Hockey.

    ERIC Educational Resources Information Center

    Theberge, Nancy

    1995-01-01

    Examines the construction of community on a women's ice hockey team, using data from fieldwork and interviews with one Canadian team. Results indicated that the locker room provided a space where players came together as hockey players and women. A common focus on hockey united the diverse group. (SM)

  16. Field Hockey-Lacrosse Guide with Official Rules. June 1972 - June 1974.

    ERIC Educational Resources Information Center

    Thornburg, Mary Lou, Ed.; Pitts, Jackie, Ed.

    Rules for women's field hockey and lacrosse from June 1972 to June 1974 are discussed. Standards in sports for girls and women are detailed as is the Division for Girls and Women's Sports (DGWS) statement of beliefs. Specific articles on field hockey techniques, skills, services available through the United States Field Hockey Association, rules,

  17. Media Coverage of Boys' and Girls' High School Ice Hockey in Minnesota.

    ERIC Educational Resources Information Center

    Woodcock, Amy Terhaar

    1995-01-01

    Reports a study that compared the newspaper coverage of girls' and boys' high school hockey teams in Minnesota from November 1994 to March 1995. Researchers coded each newspaper article for sex, length, and photo types. Results indicated that boys' high school hockey received much more newspaper coverage than girls' high school hockey. (SM)

  18. Review of typical ice hockey injuries. Survey of the North American NHL and Hockey Canada versus European leagues.

    PubMed

    Biasca, N; Simmen, H P; Bartolozzi, A R; Trentz, O

    1995-05-01

    Ice hockey is considered to be one of the fastest and roughest of all sports. Prospective injury reports of the North American National Hockey League, the Canadian Amateur Hockey Association and of several European teams (UdSSR, CSSR, Sweden and Switzerland) are reviewed to evaluate the patterns, anatomic locations, circumstances and sequelae of ice hockey-related injuries. Although different injury reporting systems are used in North America and Europe, knee injuries (sprains of the collateral ligaments) accounted for the majority of games missed (40%), followed by injuries to the shoulder (dislocation, acromio-clavicular joint separation, rotator cuff strain and tears, 20%), the groin (15%), and the back (10%). Mandatory helmets and face masks reduced the number of facial and eye injuries to a quarter from 1972 to 1983. The frequency of only concussion but also cervical spine lesions is increasing. The prevention of head, face, eye and neck injuries should mainly be accomplished by enforcement of current rules (mandatory helmets with face masks) and institution of new rules. Improvement in protective equipment would also have the effect of decreasing the frequency of injuries. Ice hockey is the fastest team sport and involves both finesse and controlled aggression. It is also considered to be one of the roughest of all sports. In recent years, ice hockey has grown tremendously in popularity, not only in the United States and in Canada but also in many European countries [1]. The number of both professional and amateur hockey players has increased with the expanding interest in the sport around the world [1].(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7610390

  19. Spondylolysis in Elite Junior-Level Ice Hockey Players

    PubMed Central

    Donaldson, Laurie D.

    2014-01-01

    Background: Spondylolysis is a common cause of low back pain and significant loss of play in the young athlete. Its incidence in hockey players has not been reported. This study reviewed the incidence and potential causative factors of low back pain and spondylolysis in an elite junior-level ice hockey program over a 15-year period. Hypothesis: Because of the repetitive movements of the lower spine required by the sport, spondylolysis was expected to be a frequent cause of low back pain in hockey players. Study Design: Retrospective case review. Level of Evidence: Level 4. Methods: The medical and athletic trainer records of male ice hockey players, ages 15 to 18 years, who presented with the complaint of low back pain were reviewed. This elite program consisted of 2 rosters. There were approximately 44 players total per year representing these 2 teams. For players diagnosed with spondylolysis, the following factors were reviewed: year in the program, age at presentation, symptoms and duration, studies performed, level of spondylolysis, presence of spondylolisthesis, affected side to shooting side, player position, treatment, and current level of play. Results: Over 9 hockey seasons, 25 players presented to medical staff with low back pain. Of those, 44% were confirmed to have lumbar spondylolysis. The majority of these cases presented in the first year of the program without clear history of trauma but rather vague pain with weight lifting or hockey. Less than half of spondylolysis cases were diagnosed on plain films. There were no cases of spondylolisthesis. Spondylolysis occurred on the shooting side in 73% of players. Sixty-four percent of players with spondylolysis were forwards. The treatment for most included rest from lifting and hockey and physical therapy. Average return to play was 8 weeks. Ninety-six percent of players continued to play at an elite level. Conclusion: Spondylolysis should be strongly considered in the differential of low back pain in ice hockey players with consideration for advanced imaging. Considerable loss of play occurs with spondylolysis, but with proper treatment, excellent outcomes occur. Clinical Relevance: This study brings to light the prevalence of spondylolysis in ice hockey players. With an increased index of suspicion, the condition can be diagnosed and properly treated to allow full return to play. PMID:24982710

  20. Measurement of head impacts in youth ice hockey players.

    PubMed

    Reed, N; Taha, T; Keightley, M; Duggan, C; McAuliffe, J; Cubos, J; Baker, J; Faught, B; McPherson, M; Montelpare, W

    2010-11-01

    Despite growing interest in the biomechanical mechanisms of sports-related concussion, ice hockey and the youth sport population has not been studied extensively. The purpose of this pilot study was: 1) to describe the biomechanical measures of head impacts in youth minor ice hockey players; and, 2) to investigate the influence of player and game characteristics on the number and magnitude of head impacts. Data was collected from 13 players from a single competitive Bantam boy's (ages 13-14 years) AAA ice hockey team using telemetric accelerometers implanted within the players' helmets at 27 ice hockey games. The average linear acceleration, rotational acceleration, Gadd Severity Index and Head Injury Criterion of head impacts were recorded. A significantly higher number of head impacts per player per game were found for wingers when compared to centre and defense player positions (df=355, t=3.087, p=0.00218) and for tournament games when compared to regular season and playoff games (df=355, t=2.641, p=0.086). A significant difference in rotational acceleration according to player position (F2,1812=4.9551, p=0.0071) was found. This study is an initial step towards a greater understanding of head impacts in youth ice hockey. PMID:20830655

  1. Are There Differences in Ice Hockey Injuries Between Sexes?

    PubMed Central

    MacCormick, Lauren; Best, Thomas M.

    2014-01-01

    Background: Mens ice hockey allows for body checking, and womens ice hockey prohibits it. Studies have reported injury data on both sexes, but no systematic reviews have compared the injury patterns between male and female ice hockey players. Hypothesis: Mens and womens ice hockey would have different types of injuries, and this difference would extend across the different age groups and levels of play. Study Design: Systematic review; Level of evidence, 4. Methods: Three databases, 3 scientific journals, and selected bibliographies were searched to identify articles relevant to this study. Articles were further screened by the use of predetermined inclusion and exclusion criteria. Twenty-two studies met these criteria and were subsequently reviewed. Results: Men sustained higher rates of injuries than women at all age levels, and both sexes sustained at least twice as many injuries in games than practices. Both sexes sustained most of their injuries from player contact. Men and women in college sustained most injuries to the head and face, and women suffered from higher percentages of concussion. At all ages and levels of play, men had higher rates of upper extremity injuries (shoulder), while women were found to sustain more injuries to the lower extremity (thigh, knee). Conclusion: Although findings showed men sustaining higher rates of injuries than women, the predominant mechanism of player contact was the same. The most common locations and types of injuries in female ice hockey players are comparable to other sports played by women, and similar interventions could offer protection against injury. Clinical Relevance: Further studies that report injury data for women playing ice hockey at all levels will assist in understanding what prevention strategies should be implemented. PMID:26535265

  2. Injuries in Youth Hockey. On-Ice Emergency Care.

    ERIC Educational Resources Information Center

    Blanchard, Bradford M.; Castaldi, Cosmo R.

    1991-01-01

    Reviews the nature and frequency of injuries in youth hockey (which range from musculoskeletal injuries to life-threatening emergencies). Overall injury rates have decreased, but there is an increase in head, neck, and spine injuries. Those injuries that are serious demand prompt, skillful attention. A comprehensive format for on-ice management is…

  3. Field Hockey; Lacrosse, June 1976-June 1978. NAGWS Guide.

    ERIC Educational Resources Information Center

    Nixon, Linda K., Ed.; Hess, Eleanor Kay, Ed.

    This guide for field hockey and lacrosse is one in a series of guides for 22 sports published by the National Association for Girls and Women in Sport (NAGWS). Guides contain information on NAGWS-approved playing rules, officials' ratings, articles on teaching, coaching and organization, regulations governing national championships,

  4. Expert-novice differences in brain function of field hockey players.

    PubMed

    Wimshurst, Z L; Sowden, P T; Wright, M

    2016-02-19

    The aims of this study were to use functional magnetic resonance imaging to examine the neural bases for perceptual-cognitive superiority in a hockey anticipation task. Thirty participants (15 hockey players, 15 non-hockey players) lay in an MRI scanner while performing a video-based task in which they predicted the direction of an oncoming shot in either a hockey or a badminton scenario. Video clips were temporally occluded either 160ms before the shot was made or 60ms after the ball/shuttle left the stick/racquet. Behavioral data showed a significant hockey expertise×video-type interaction in which hockey experts were superior to novices with hockey clips but there were no significant differences with badminton clips. The imaging data on the other hand showed a significant main effect of hockey expertise and of video type (hockey vs. badminton), but the expertise×video-type interaction did not survive either a whole-brain or a small-volume correction for multiple comparisons. Further analysis of the expertise main effect revealed that when watching hockey clips, experts showed greater activation in the rostral inferior parietal lobule, which has been associated with an action observation network, and greater activation than novices in Brodmann areas 17 and 18 and middle frontal gyrus when watching badminton videos. The results provide partial support both for domain-specific and domain-general expertise effects in an action anticipation task. PMID:26674059

  5. Benthic re-colonization in post-dredging pits in the Puck Bay (Southern Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Szymelfenig, Maria; Kotwicki, Lech; Graca, Bo?ena

    2006-07-01

    The stage of benthic re-colonization at a site formed by sand extraction was investigated some 10 years after the cessation of dredging. The examined post-dredging pit is one of five deep (up to 14 m) pits created with a static suction hopper on the sandy, flat and shallow (1-2 m) part of the inner Puck Bay (the southern Baltic Sea). The topography of the dredged area makes a specific trap for different kinds of organic matter. It is created by the small areas of post-dredging pits as compared to their depths. As a result, organic matter accumulation leads to anaerobic conditions and hydrogen sulfide formation. Macrofauna was not found to occur permanently in the deepest part (11 m) of the cup-shaped depression, which was characterized by its small area (0.2 km 2) and steep walls. However, permanent occurrence of meiofauna (max. 180 ind. 10 cm -2, mainly Nematoda) was noted. Undoubtedly, re-colonization of benthic fauna assemblages, typical of shallow and sandy seabed of the Puck Bay, will not follow in a natural way in the area of post-dredging pits. Also, it could not be expected that the re-colonization sequence would result in the formation of a structure similar to that of the natural depression (the Ku?nica Hollow).

  6. Position Statement. Violence and injury in ice hockey.

    PubMed

    Juhn, Mark S; Brolinson, Per Gunnar; Duffey, Timothy; Stockard, Alan; Vangelos, Zenos A; Emaus, Erik; Maddox, Matthew; Boyajian, Lori; Henehan, Michael

    2002-01-01

    Ice hockey is a sport enjoyed by many men and women at the spectator and participant level. It is played with high intensity and often involves body contact. Although the women's games is far from injury free, it is the men's game that has drawn criticism for excessive violence. Much attention has been drawn to the serious injuries that have occurred in ice hockey, specifically spinal injuries, concussions, and eye injuries. Many such injuries are the result of illegal and violent acts such as checking from behind or a deliberate high stick. Because of this, some medical organizations have called for changes in the sport, such as minimum age requirements for body-checking. As a practical matter such changes are unlikely to be accepted by hockey governing boards. Many of those involved in the sport consider body-checking a fundamental component of the game. Furthermore, a distinction needs to be made between any kind of injury and a serious, catastrophic injury. For example, although a recent study found that body-checking accounted for up to 38% of ice hockey injuries, none were of the catastrophic type. With respect to catastrophic injuries such as spinal cord trauma or a blinded eye, legal body-checking accounts for significantly less than illegal body-checking (e.g., checking from behind) or violent stick work. To reduce serious injury in ice hockey, we offer 10 recommendations, key among them automatic game suspensions for certain rules violations, and recognition of the coach as the most important figure in promoting a clean, safe game. PMID:11854591

  7. Aerobic Development of Elite Youth Ice Hockey Players.

    PubMed

    Leiter, Jeff R; Cordingley, Dean M; MacDonald, Peter B

    2015-11-01

    Ice hockey is a physiologically complex sport requiring aerobic and anaerobic energy metabolism. College and professional teams often test aerobic fitness; however, there is a paucity of information regarding aerobic fitness of elite youth players. Without this knowledge, training of youth athletes to meet the standards of older age groups and higher levels of hockey may be random, inefficient, and or effective. Therefore, the purpose of this study was to determine the aerobic fitness of elite youth hockey players. A retrospective database review was performed for 200 male AAA hockey players between the ages of 13 and 17 (age, 14.4 ± 1.2 years; height, 174.3 ± 8.5 cm; body mass, 67.2 ± 11.5 kg; body fat, 9.8 ± 3.5%) before the 2012-13 season. All subjects performed a graded exercise test on a cycle ergometer, whereas expired air was collected by either a Parvo Medics TrueOne 2400 or a CareFusion Oxycon Mobile metabolic cart to determine maximal oxygen consumption (V[Combining Dot Above]O2max). Body mass, absolute V[Combining Dot Above]O2max, and the power output achieved during the last completed stage increased in successive age groups from age 13 to 15 years (p ≤ 0.05). Ventilatory threshold (VT) expressed as a percentage of V[Combining Dot Above]O2max and the heart rate (HR) at which VT occurred decreased between the ages of 13 and 14 years (p ≤ 0.05), whereas the V[Combining Dot Above]O2 at which VT occurred increased from the age of 14-15 years. There were no changes in relative V[Combining Dot Above]O2max or HRmax between any successive age groups. The aerobic fitness levels of elite youth ice hockey players increased as players age and mature physically and physiologically. However, aerobic fitness increased to a lesser extent at older ages. This information has the potential to influence off-season training and maximize the aerobic fitness of elite amateur hockey players, so that these players can meet standards set by advanced elite age groups. PMID:26506063

  8. Effects of multiple concussions on retired national hockey league players.

    PubMed

    Caron, Jeffrey G; Bloom, Gordon A; Johnston, Karen M; Sabiston, Catherine M

    2013-04-01

    The purpose of this study was to understand the meanings and lived experiences of multiple concussions in professional hockey players using hermeneutic, idiographic, and inductive approaches within an interpretative phenomenological analysis. The interviewer was an athlete who had suffered multiple concussions, and the interviewees were five former National Hockey League athletes who had retired due to medically diagnosed concussions suffered during their careers. The men discussed the physical and psychological symptoms they experienced as a result of their concussions and how the symptoms affected their professional careers, personal relationships, and quality of life. The former professional athletes related these symptoms to the turmoil that is ever present in their lives. These findings are of interest to athletes, coaches, sport administrators, family members, sport psychology practitioners, and medical professionals, as they highlight the severity of short- and long-term effects of concussions. PMID:23535975

  9. [Hemodynamic Status of Prepubertal and Pubertal Hockey Players].

    PubMed

    Shayhelislamova, M V; Sitdikov, F G; Zefirov, T L; Dikopolskaya, N B

    2015-01-01

    The hemodynamic status of 11-15-year-old hockey players depending on their age and puberty stage were studied and compared with hemodynamic parameters of the control group. It was found that regular muscle training has a dominant effect on the functional state of cardiovascular system (CVS) in prepuberty and puberty. It was proved that in hockey players a decrease in the heart rate (H R) and an increase in the stroke volume (SV) result in a significant increase in systolic blood pressure (SBP) at the age of 11-14 years and a progressive increase in total peripheral vascular resistance (PVR), in contrast to significantly lower values in the control group. The urgent adaptation of CVS to graduated physical activities at the age of 11-13 years leads to an enhancement of vascular spasmodic reactions while SV remains constant. It was found that in adolescent hockey players have consistently high SV and SBP; at the same time, maximal values of HR, cardiac output (CO) and diastolic blood pressure (DBP) were observed at the stages I and II of the puberty period; then, at the stage III, these parameters decrease. I n the control group, hymodinamic status changed in an opposite way. This may be an evidence of the stress effect of physical activities which results in the adaptive reactions of CVS rather than reactions typical of the puberty period. PMID:26485793

  10. SnapShot: Visualization to Propel Ice Hockey Analytics.

    PubMed

    Pileggi, H; Stolper, C D; Boyle, J M; Stasko, J T

    2012-12-01

    Sports analysts live in a world of dynamic games flattened into tables of numbers, divorced from the rinks, pitches, and courts where they were generated. Currently, these professional analysts use R, Stata, SAS, and other statistical software packages for uncovering insights from game data. Quantitative sports consultants seek a competitive advantage both for their clients and for themselves as analytics becomes increasingly valued by teams, clubs, and squads. In order for the information visualization community to support the members of this blossoming industry, it must recognize where and how visualization can enhance the existing analytical workflow. In this paper, we identify three primary stages of today's sports analyst's routine where visualization can be beneficially integrated: 1) exploring a dataspace; 2) sharing hypotheses with internal colleagues; and 3) communicating findings to stakeholders.Working closely with professional ice hockey analysts, we designed and built SnapShot, a system to integrate visualization into the hockey intelligence gathering process. SnapShot employs a variety of information visualization techniques to display shot data, yet given the importance of a specific hockey statistic, shot length, we introduce a technique, the radial heat map. Through a user study, we received encouraging feedback from several professional analysts, both independent consultants and professional team personnel. PMID:26357191

  11. THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY

    PubMed Central

    Del Valle, M.E.; Egocheaga, J.; Linnamo, V.; Fernndez, A.

    2013-01-01

    The aim of this study was to simulate the activity pattern of rink hockey by designing a specific skate test (ST) to study the energy expenditure and metabolic responses to this intermittent high-intensity exercise and extrapolate the results from the test to competition. Six rink hockey players performed, in three phases, the 20-metre multi-stage shuttle roller skate test, a tournament match and the ST. Heart rate was monitored in all three phases. Blood lactate, oxygen consumption, ventilation and respiratory exchange ratio were also recorded during the ST. Peak HR was 190.77.2 beats min?1. There were no differences in peak HR between the three tests. Mean HR was similar between the ST and the match (86% and 87% of HRmax, respectively). Peak and mean ventilation averaged 111.08.8 L min?1 and 70.314.0 L min?1 (60% of VEmax), respectively. VO2max was 56.38.4 mL kg?1 min?1, and mean oxygen consumption was 40.97.9 mL kg?1 min?1 (70% of VO2max). Maximum blood lactate concentration was 7.21.3 mmol L-1. ST yielded an energy expenditure of 899.1232.9 kJ, and energy power was 59.915.5 kJ min?1. These findings suggest that the ST is suitable for estimating the physiological demands of competitive rink hockey, which places a heavy demand on the aerobic and anaerobic systems, and requires high energy consumption. PMID:24744488

  12. Playing Hockey, Riding Motorcycles, and the Ethics of Protection

    PubMed Central

    2012-01-01

    Ice hockey and motorcycle riding are increasingly popular activities in the United States that are associated with high risks of head and facial injuries. In both, effective head and facial protective equipment are available. Yet the debates about safety policies regarding the use of head protection in these activities have taken different forms, in terms of the influence of epidemiological data as well as of the ethical concerns raised. I examine these debates over injury prevention in the context of leisure activities, in which the public health duty to prevent avoidable harm must be balanced with the freedom to assume voluntary risks. PMID:23078472

  13. Relationship between hockey skating speed and selected performance measures.

    PubMed

    Behm, David G; Wahl, Michael J; Button, Duane C; Power, Kevin E; Anderson, Kenneth G

    2005-05-01

    The objective of this study was to determine the relationship between specific performance measures and hockey skating speed. Thirty competitive secondary school and junior hockey players were timed for skating speed. Off-ice measures included a 40-yd (36.9-m) sprint, concentric squat jump, drop jump, 1 repetition maximum leg press, flexibility, and balance ratio (wobble board test). Pearson product moment correlations were used to quantify the relationships between the variables. Electromyographic (EMG) activity of the dominant vastus lateralis and biceps femoris was monitored in 12 of the players while skating, stopping, turning, and performing a change-of-direction drill. Significant correlations (p < 0.005) were found between skating performance and the sprint and balance tests. Further analysis demonstrated significant correlations between balance and players under the age of 19 years (r = -0.65) but not those over 19 years old (r = -0.28). The significant correlations with balance suggested that stability may be associated with skating speed in younger players. The low correlations with drop jumps suggested that short contact time stretch-shortening activities (i.e., low amplitude plyometrics) may not be an important factor. Electromyographic activities illustrated the very high activation levels associated with maximum skating speed. PMID:15903370

  14. Age and competition level on injuries in female ice hockey.

    PubMed

    Keightley, M; Reed, N; Green, S; Taha, T

    2013-08-01

    The objective of this study was to describe the number, types and locations of known injuries occurring across different age categories and levels of competition in female ice hockey within the Ontario Women's Hockey Association from 2004/05 to 2007/08. We further examined under which aforementioned factors and combination of factors an unusually high or low number of injuries was recorded. Secondary analysis of anonymized injury data was conducted. The most common known injury type was strain/sprain, followed by concussion while the most frequent injury location was head/face/mouth. Analysis of deviance indicated that a significantly higher than expected number of sprain/strain, concussion and laceration injuries were recorded compared to all other injury types. In addition, there were a higher number of injuries recorded at the AA level compared to all other levels of competition. Finally, the age categories of Peewee, Midget and Intermediate within the AA level of competition, as well as Senior/Adult within the Houseleague level of competition also recorded a significantly higher number of injuries compared to other combinations of descriptive factors. Further research with female youth is needed to better understand the high number of injuries, including concussions, reported overall. PMID:23516144

  15. Tuning aerosol performance using the multibreath Orbital dry powder inhaler device: controlling delivery parameters and aerosol performance via modification of puck orifice geometry.

    PubMed

    Zhu, Bing; Young, Paul M; Ong, Hui Xin; Crapper, John; Flodin, Carina; Qiao, Erin Lin; Phillips, Gary; Traini, Daniela

    2015-07-01

    The current study presents a new approach to tackle high-dose lung delivery using a prototype multibreath Orbital dry powder inhaler (DPI). One of the key device components is the "puck" (aerosol sample chamber) with precision-engineered outlet orifice(s) that control the dosing rate. The influence of puck orifice geometry and number of orifices on the performance of mannitol aerosols were studied. Pucks with different orifice configurations were filled with 400 mg of spray-dried mannitol and tested in the Orbital DPI prototype. The emitted dose and overall aerodynamic performance across a number of "breaths" were studied using a multistage liquid impinger. The aerosol performances of the individual actuations were investigated using in-line laser diffraction. The emptying rate of all pucks was linear between 20% and 80% cumulative drug released (R(2) > 0.98), and the amount of formulation released per breath could be controlled such that the device was empty after 2 to 11 breath maneuvers. The puck-emptying rate linearly related to the orifice hole length (R(2) > 0.95). Mass median aerodynamic diameters of the emitted aerosol ranged from 4.03 to 4.62 ?m and fine particle fraction (?6.4 ?m) were 50%-66%. Laser diffraction suggested that the aerosol performance and emptying rates were not dependent on breath number, showing consistent size distribution profiles. PMID:25931324

  16. The Effect of a Complex Training Program on Skating Abilities in Ice Hockey Players

    PubMed Central

    Lee, Changyoung; Lee, Sookyung; Yoo, Jaehyun

    2014-01-01

    [Purpose] Little data exist on systemic training programs to improve skating abilities in ice hockey players. The purpose of this study was to evaluate the effectiveness of a complex training program on skating abilities in ice hockey players. [Methods] Ten male ice hockey players (training group) that engaged in 12 weeks of complex training and skating training and ten male players (control group) that only participated in 12 weeks of skating training completed on-ice skating tests including a 5 time 18 meters shuttle, t-test, Rink dash 5 times, and line drill before, during, and the training. [Results] Significant group-by-time interactions were found in all skating ability tests. [Conclusion] The complex training program intervention for 12 weeks improved their skating abilities of the ice hockey players. PMID:24764628

  17. Reducing injury risk from body checking in boys' youth ice hockey.

    PubMed

    Brooks, Alison; Loud, Keith J; Brenner, Joel S; Demorest, Rebecca A; Halstead, Mark E; Kelly, Amanda K Weiss; Koutures, Chris G; LaBella, Cynthia R; LaBotz, Michele; Martin, Stephanie S; Moffatt, Kody

    2014-06-01

    Ice hockey is an increasingly popular sport that allows intentional collision in the form of body checking for males but not for females. There is a two- to threefold increased risk of all injury, severe injury, and concussion related to body checking at all levels of boys' youth ice hockey. The American Academy of Pediatrics reinforces the importance of stringent enforcement of rules to protect player safety as well as educational interventions to decrease unsafe tactics. To promote ice hockey as a lifelong recreational pursuit for boys, the American Academy of Pediatrics recommends the expansion of nonchecking programs and the restriction of body checking to elite levels of boys' youth ice hockey, starting no earlier than 15 years of age. PMID:24864185

  18. Ice Hockey Summit II: zero tolerance for head hits and fighting.

    PubMed

    Smith, Aynsley M; Stuart, Michael J; Dodick, David W; Roberts, William O; Alford, Patrick W; Ashare, Alan B; Aubrey, Mark; Benson, Brian W; Burke, Chip J; Dick, Randall; Eickhoff, Chad; Emery, Carolyn A; Flashman, Laura A; Gaz, Daniel V; Giza, Chris C; Greenwald, Richard M; Herring, Stanley A; Hoshizaki, T Blaine; Hudziak, James J; Huston, John; Krause, David; LaVoi, Nicole; Leaf, Matt; Leddy, John J; MacPherson, Alison; McKee, Ann C; Mihalik, Jason P; Moessner, Anne M; Montelpare, William J; Putukian, Margot; Schneider, Kathryn J; Szalkowski, Ron; Tabrum, Mark; Whitehead, James R; Wiese-Bjornstal, Diane M

    2015-01-01

    This study aimed to present currently known basic science and on-ice influences of sport-related concussion (SRC) in hockey, building upon the Ice Hockey Summit I action plan (2011) to reduce SRC. The prior summit proceedings included an action plan intended to reduce SRC. As such, the proceedings from Summit I served as a point of departure for the science and discussion held during Summit II (Mayo Clinic, Rochester, MN, October 2013). Summit II focused on (1) Basic Science of Concussions in Ice Hockey: Taking Science Forward, (2) Acute and Chronic Concussion Care: Making a Difference, (3) Preventing Concussions via Behavior, Rules, Education, and Measuring Effectiveness, (4) Updates in Equipment: Their Relationship to Industry Standards, and (5) Policies and Plans at State, National, and Federal Levels To Reduce SRC. Action strategies derived from the presentations and discussion described in these sectors were voted on subsequently for purposes of prioritization. The following proceedings include the knowledge and research shared by invited faculty, many of whom are health care providers and clinical investigators. The Summit II evidence-based action plan emphasizes the rapidly evolving scientific content of hockey SRC. It includes the most highly prioritized strategies voted on for implementation to decrease concussion. The highest-priority action items identified from the Summit include the following: (1) eliminate head hits from all levels of ice hockey, (2) change body checking policies, and (3) eliminate fighting in all amateur and professional hockey. PMID:25757010

  19. Video gaming promotes concussion knowledge acquisition in youth hockey players.

    PubMed

    Goodman, David; Bradley, Nori L; Paras, Bradley; Williamson, Ian J; Bizzochi, James

    2006-06-01

    While the positive uses for video games in an educational setting have also been established, the educational aim is usually made explicit. The goal of this research was to develop a video game wherein the educational aspect was implicitly embedded in the video game, such that the gaming activity remained interesting and relevant. Following a pilot study to confirm the usability of an in-house developed game, two studies were conducted with 11-17 year old hockey players (N(1)=130, N(2)=39). Results demonstrated that participants playing the experimental version of the video game scored significantly higher on a concussion symptoms questionnaire, in a significantly faster time, than participants playing the control version of the game. Most participants indicated that they enjoyed the game and would play it again. These results suggest that educational material can be conveyed successfully and in an appealing manner via video game play. PMID:16169584

  20. Children's social relationships and motivation in sledge hockey.

    PubMed

    Wynnyk, Katrina; Spencer-Cavaliere, Nancy

    2013-10-01

    The purpose of this qualitative case study was to explore children with disabilities' social relationships and motivation to take part in sledge hockey. Harter's (1978) theory of Competence Motivation was used as the conceptual framework. Ten children (1 girl and 9 boys) between ages 11-16 years, who experienced a range of disabilities, participated. Primary data were collected using semistructured interviews, participant observations, and field and reflective notes. The thematic analysis led to four themes: (a) coach feedback, (b) parental involvement, (c) skill and belonging, and (d) (dis)ability sport. The findings revealed that interactions with significant others contributed extensively to the participant's perceptions of competence and motivation to participate, as did the sport's competitive nature. The findings are discussed in the context of Harter's theory and the children's sport and adapted physical activity inclusion literature. PMID:24197621

  1. Career/Life Transition Needs of National Hockey League Players and Career-Life Transition Needs of National Hockey League Players: Spouses Perspectives. Final Reports Prepared for the National Hockey League Players' Association.

    ERIC Educational Resources Information Center

    Blann, Wayne; Zaichkowsky, Leonard

    Two surveys were conducted regarding the career and life transition needs of National Hockey League (NHL) players and their spouses. The Professional Athletes' Career Transition Inventory was distributed to player representatives and members of eight NHL teams. Results revealed that 85 percent of players believed it important that help be provided

  2. A comparison of the epidemiology of ice hockey injuries between male and female youth in Canada

    PubMed Central

    Forward, Karen E; Seabrook, Jamie A; Lynch, Tim; Lim, Rodrick; Poonai, Naveen; Sangha, Gurinder S

    2014-01-01

    BACKGROUND: Hockey is played by youth across Canada, and its popularity has increased dramatically among females in the past decade. Despite this, there has been little epidemiological research comparing the injury patterns of young female and male hockey players. OBJECTIVE: To describe and compare injuries sustained by female and male youth hockey players using the Canadian Hospitals Injury Reporting and Prevention Program database. METHODS: In the present cross-sectional, retrospective comparison study, the Canadian Hospitals Injury Reporting and Prevention Program database was used to identify all hockey-related injuries sustained by children seven to 17.5 years of age over a 15-year period (January 1995 to December 2009). Exclusion criteria included paid professional players and children with injuries sustained while playing road hockey. RESULTS: Inclusion criteria were met by 33,233 children (2637 [7.9%] females and 30,596 [92.1%] males). Compared with males, females reported proportionately more soft tissue injuries (39.8% versus 32.6%; P<0.01) and sprains/strains (21.1% versus 17.6%; P<0.01). Males experienced more fractures (27.1% versus 18.2%; P<0.01) and were most often injured through body checking (42.8% versus 25.7%; P<0.01). Females showed a trend toward increased concussion with age, and were most often injured through collisions (28.6% versus 24.6%; P<0.01). CONCLUSION: Compared with males, female hockey players sustained proportionately more soft tissue injures and sprains/strains, and showed a trend toward concussions in late adolecence. Males experienced more fractures, shoulder injuries and injuries due to body checking. Further research is required to identify risk factors for injury in female youth hockey players and to target injury prevention. PMID:25382998

  3. Proceedings from the Ice Hockey Summit on concussion: a call to action.

    PubMed

    Smith, A; Stuart, M; Greenwald, R; Benson, B; Dodick, D; Emery, C; Finnoff, J; Mihalik, J; Roberts, W; Sullivan, C A; Meeuwisse, W

    2011-07-01

    The objective of this proceedings is to integrate the concussion in sport literature and sport science research on safety in ice hockey to develop an action plan to reduce the risk, incidence, severity, and consequences of concussion in ice hockey. A rationale paper outlining a collaborative action plan to address concussions in hockey was posted for review two months prior to the Ice Hockey Summit: Action on Concussion. Focused presentations devoted specifically to concussion in ice hockey were presented during the Summit and breakout sessions were used to develop strategies to reduce concussion in the sport. This proceedings and a detailed scientific review (a matrix of solutions) were written to disseminate the evidence-based information and resulting concussion reduction strategies. The manuscripts were reviewed by the authors, advisors and contributors to ensure that the opinions and recommendations reflect the current level of knowledge on concussion in hockey. Six components of a potential solution were articulated in the Rationale paper and became the topics for breakout groups that followed the professional, scientific lectures. Topics that formed the core of the action plan were: metrics and databases; recognizing, managing and return to play; hockey equipment and ice arenas; prevention and education; rules and regulations; and expedient communication of the outcomes. The attendees in breakout sessions identified action items for each section. The most highly ranked action items were brought to a vote in the open assembly, using an Audience Response System (ARS). The strategic planning process was conducted to assess: Where are we at?; Where must we get to?; and What strategies are necessary to make progress on the prioritized action items? Three prioritized action items for each component of the solution and the percentage of the votes received are listed in the body of this proceedings. PMID:21756209

  4. Physiological, physical and on-ice performance criteria for selection of elite ice hockey teams.

    PubMed

    Roczniok, R; Stanula, A; Maszczyk, A; Mostowik, A; Kowalczyk, M; Fidos-Czuba, O; Zając, A

    2016-03-01

    The purpose of this study was to examine physiological and physical determinants of ice-hockey performance in order to assess their impact on the result during a selection for ice hockey. A total of 42 ice hockey players took part in the selection camp. At the end of the camp 20 best players were selected by team of expert coaches to the ice hockey team and created group G1, while the second group (G2) consisted of not selected players (non-successful group Evaluation of goodness of fit of the model to the data was based on the Hosmer Lemeshow test. Ice hockey players selected to the team were taller 181.95±4.02 cm, had lower% body fat 13.17±3.17%, a shorter time to peak power 2.47±0.35 s, higher relative peak power 21.34±2.41 W·kg(-1) and higher relative total work 305.18±28.41 J·kg(-1). The results of the aerobic capacity test showed significant differences only in case of two variables. Ice hockey players in the G1 had higher VO2max 4.07±0.31 l·min(-1) values than players in the G2 as well as ice hockey players in G1 showed a higher level of relative VO2max 51.75±2.99 ml·min(-1)·kg(-1) than athletes in G2. Ice hockey players selected to the team (G1) performed better in the 30 m Forwards Sprint 4.28±0.31 s; 6x9 Turns 12.19±0.75 s; 6x9 stops 12.79±0.49 s and Endurance test (6x30 m stops) 32.01±0.80 s than players in G2. The logistic regression model showed that the best predictors of success in the recruitment process of top level ice hockey players were time to peak power, relative peak power, VO2max and 30 m sprint forwards on ice. On the basis of the constructed predictive logistic regression model it will be possible to determine the probability of success of the athletes during following the selection processes to the team. PMID:26985133

  5. Physiological, physical and on-ice performance criteria for selection of elite ice hockey teams

    PubMed Central

    Roczniok, R; Stanula, A; Mostowik, A; Kowalczyk, M; Fidos-Czuba, O; Zając, A

    2015-01-01

    The purpose of this study was to examine physiological and physical determinants of ice-hockey performance in order to assess their impact on the result during a selection for ice hockey. A total of 42 ice hockey players took part in the selection camp. At the end of the camp 20 best players were selected by team of expert coaches to the ice hockey team and created group G1, while the second group (G2) consisted of not selected players (non-successful group Evaluation of goodness of fit of the model to the data was based on the Hosmer Lemeshow test. Ice hockey players selected to the team were taller 181.95±4.02 cm, had lower% body fat 13.17±3.17%, a shorter time to peak power 2.47±0.35 s, higher relative peak power 21.34±2.41 W·kg−1 and higher relative total work 305.18±28.41 J·kg−1. The results of the aerobic capacity test showed significant differences only in case of two variables. Ice hockey players in the G1 had higher VO2max 4.07±0.31 l·min−1 values than players in the G2 as well as ice hockey players in G1 showed a higher level of relative VO2max 51.75±2.99 ml·min−1·kg−1 than athletes in G2. Ice hockey players selected to the team (G1) performed better in the 30 m Forwards Sprint 4.28±0.31 s; 6x9 Turns 12.19±0.75 s; 6x9 stops 12.79±0.49 s and Endurance test (6x30 m stops) 32.01±0.80 s than players in G2. The logistic regression model showed that the best predictors of success in the recruitment process of top level ice hockey players were time to peak power, relative peak power, VO2max and 30 m sprint forwards on ice. On the basis of the constructed predictive logistic regression model it will be possible to determine the probability of success of the athletes during following the selection processes to the team. PMID:26985133

  6. Game Intensity Analysis of Elite Adolescent Ice Hockey Players

    PubMed Central

    Stanula, Arkadiusz; Roczniok, Robert

    2014-01-01

    The purpose of this study was to determine ice-hockey players’ playing intensity based on their heart rates (HRs) recorded during a game and on the outcomes of an incremental maximum oxygen uptake test. Twenty ice-hockey players, members of the Polish junior national team (U18), performed an incremental test to assess their maximal oxygen uptake (V̇O2max) in the two week’s period preceding 5 games they played at the World Championships. Players’ HRs at the first and second ventilatory thresholds obtained during the test were utilized to determine intensity zones (low, moderate, and high) that were subsequently used to classify HR values recorded during each of the games. For individual intensity zones, the following HRs expressed as mean values and as percentages of the maximal heart rate (HRmax) were obtained: forwards 148–158 b·min−1 (79.5–84.8% HRmax), 159–178 b·min−1 (85.4–95.6% HRmax), 179–186 b·min−1 (96.1–100.0% HRmax); defensemen 149–153 b·min−1 (80.0–82.1% HRmax), 154–175 b·min−1 (82.6–94.0% HRmax), 176–186 b·min−1 (94.5–100.0% HRmax). The amount of time the forwards and defensemen spent in the three intensity zones expressed as percentages of the total time of the game were: 54.91 vs. 55.62% (low), 26.40 vs. 22.38% (moderate) and 18.68 vs. 22.00% (high). The forwards spent more time in the low intensity zone than the defensemen, however, the difference was not statistically significant. The results of the study indicate that using aerobic and anaerobic metabolism variables to determine intensity zones can significantly improve the reliability of evaluation of the physiological demands of the game, and can be a useful tool for coaches in managing the training process. PMID:25713682

  7. Conservative management of an elite ice hockey goaltender with femoroacetabular impingement (FAI): a case report

    PubMed Central

    MacIntyre, Kyle; Gomes, Brendan; MacKenzie, Steven; D’Angelo, Kevin

    2015-01-01

    Objective: To detail the presentation of an elite male ice hockey goaltender with cam-type femoroacetabular impingement (FAI) and acetabular labral tears. This case will outline the prevalence, clinical presentation, imaging criteria, pathomechanics, and management of FAI, with specific emphasis on the ice hockey goaltender. Clinical Features: A 22-year old retired ice hockey goaltender presented to a chiropractor after being diagnosed by an orthopaedic surgeon with MRI confirmed left longitudinal and chondral flap acetabular labral tears and cam-type femoroacetabular impingement (FAI). As the patient was not a candidate for surgical intervention, a multimodal conservative treatment approach including manual therapy, electroacupuncture and rehabilitation exercises were implemented. Summary: FAI is prevalent in ice hockey players, particularly with goaltenders. Both skating and position-dependent hip joint mechanics involved in ice hockey may exacerbate or contribute to acquired and congenital forms of symptomatic FAI. As such, practitioners managing this population must address sport-specific demands in manual therapy, rehabilitation and physical training, to improve functional outcomes and prevent future injury. PMID:26816416

  8. Integration of the functional movement screen into the National Hockey League Combine.

    PubMed

    Rowan, Chip P; Kuropkat, Christiane; Gumieniak, Robert J; Gledhill, Norman; Jamnik, Veronica K

    2015-05-01

    The sport of ice hockey requires coordination of complex skills involving musculoskeletal and physiological abilities while simultaneously exposing players to a high risk for injury. The Functional Movement Screen (FMS) was developed to assess fundamental movement patterns that underlie both sport performance and injury risk. The top 111 elite junior hockey players from around the world took part in the 2013 National Hockey League Entry Draft Combine (NHL Combine). The FMS was integrated into the comprehensive medical and physiological fitness evaluations at the request of strength and conditioning coaches with affiliations to NHL teams. The inclusion of the FMS aimed to help develop strategies that could maximize its utility among elite hockey players and to encourage or inform further research in this field. This study evaluated the outcomes of integrating the FMS into the NHL Combine and identified any links to other medical plus physical and physiological fitness assessment outcomes. These potential associations may provide valuable information to identify elements of future training programs that are individualized to athletes' specific needs. The results of the FMS (total score and number of asymmetries identified) were significantly correlated to various body composition measures, aerobic and anaerobic fitness, leg power, timing of recent workouts, and the presence of lingering injury at the time of the NHL Combine. Although statistically significant correlations were observed, the implications of the FMS assessment outcomes remain difficult to quantify until ongoing assessment of FMS patterns, tracking of injuries, and hockey performance are available. PMID:25719918

  9. Many roads lead to Rome--developmental paths to Olympic gold in men's field hockey.

    PubMed

    Gllich, Arne

    2014-01-01

    This study examined the developmental sporting activities of the Olympic Champions 2012 in men's field hockey. The volume of organised practice/training and non-organised sporting leisure play in both field hockey and other sports through childhood, adolescence and adulthood was examined and compared between the Olympic Champions and (1) current national class players and (2) international medallists of one decade earlier. Analyses revealed that the Olympic Champions performed moderate volumes of organised field hockey practice/training throughout their career and attained their first international senior medal after accumulating 4393 1389 practice/training hours, but they engaged in extensive other sporting activities during childhood and youth. It took them 18 3 years of involvement to attain an international medal and they had engaged for 22 3 years when winning the Olympic gold medal. The Olympic Champions did not differ from national class players in the amount of hockey-specific practice/training, but in greater amounts of organised involvement in other sports and later specialisation. They differed from the international medallists of one decade earlier in less increase of organised hockey-specific practice/training during adulthood and a longer period of involvement until attaining their first international medal. The sporting activities were characterised by sizeable interindividual variation within each subsample. The findings are reflected against the deliberate practice and Developmental Model of Sports Participation (DMSP) frameworks and are discussed with reference to the concept of long-term sustainability. PMID:24707887

  10. Neuropsychological factors related to college ice hockey concussions.

    PubMed

    Pedersen, Heather A; Ferraro, F Richard; Himle, Michael; Schultz, Caitlin; Poolman, Mark

    2014-05-01

    We analyzed data from 74 male collegiate hockey players. Each athlete's season began with a baseline administration of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) neuropsychology test battery. Fourteen athletes sustained a sport-related head injury and were readministered the test to assess the impact of the injury. A significant decrease in performance (compared to baseline) on immediate and delayed word recall and designs followed the first concussion. Following a second sport-related concussion, the 4 affected athletes showed significant decrease in visual motor speed. Performance improved on 2 response speed measures (Ps < .01). More errors occurred during a visual processing/discrimination task and immediate recall of designs declined (Ps < .05). We discuss the results in light of recent work related to the impact of early-life concussions and head injury on late-life consequences, such as chronic traumatic encephalopathy, and more immediate issues such as return-to-play decisions for athletes. PMID:24370620

  11. Patterns of ephedra and other stimulant use in collegiate hockey athletes.

    PubMed

    Bents, Robert T; Marsh, Erik

    2006-12-01

    This study examined trends in stimulant use and attitudes toward use among American collegiate hockey athletes. All 139 players in one college hockey conference completed a comprehensive questionnaire. Over half of the athletes (51.8%) confirmed stimulant use before a hockey game or practice. About half of the respondents (48.5%) reported having used ephedra at least one time to improve athletic performance. Additionally, 17.4% reported using pseudoephedrine to improve performance in the 30 days prior to survey administration. Over half (55.4%) were aware of the recent national ban on ephedra. Fifty-nine percent stated the national ban made them less likely to use ephedra products. The majority of athletes began use prior to college. Coaches, athletic trainers, and team physicians should be aware of athletes' patterns of stimulant use. Improved educational efforts directed at younger athletes are necessary to deter abuse of metabolic stimulants. PMID:17342884

  12. Do youth hockey coaches allow players with a known concussion to participate in a game?

    PubMed

    Bramley, Harry; Kroft, Christopher; Polk, David; Newberry, Ty; Silvis, Matthew

    2012-03-01

    Ice hockey is a high-risk sport for concussion. It is important that coaches have an understanding of concussion, although previous studies have demonstrated poor knowledge of concussion recognition and management by youth coaches. A cross-sectional survey with 7 case scenarios was completed by 314 youth hockey coaches. Each case scenario described a player with a concussion during a game, and scores reflected how the coach would respond to each scenario. Although most coaches would not allow a player to continue participating in a game after suffering a concussion, there was a small percentage that would. Statistical analysis found an inverse relationship between the coaches' age and consideration of continued participation. This places athletes at significant risk for further injury and is not consistent with current concussion guidelines. USA Hockey should provide additional concussion training for their coaches as well as mandatory health care clearance following a concussion. PMID:21937746

  13. Use of computer based testing of youth hockey players with concussions.

    PubMed

    Brooks, David A

    2007-01-01

    Concussion is a potentially serious injury for athletes. Recent statistics suggest that approximately 300,000 sports-related traumatic brain injuries occur annually in the United States. Soccer, rugby, football, and ice hockey are all considered high-risk team sports for concussion. Hockey-related concussions are of particular concern in Canada, where over 500,000 players compete annually in ice hockey. The United States is now registering similar numbers of players. Return to play issues are one of the most difficult issues for physicians caring for concussed athletes. The advent of computerized neuropsychological testing adds another tool to assist in this process. It also appears to enhance the education process for players, coaches, and parents on the potential seriousness of concussion for these young athletes. PMID:17917167

  14. Gender Differences in Head Impacts Sustained by Collegiate Ice Hockey Players

    PubMed Central

    Brainard, Lindley L.; Beckwith, Jonathan G.; Chu, Jeffrey J.; Crisco, Joseph J.; McAllister, Thomas W.; Duhaime, Ann-Christine; Maerlender, Arthur C.; Greenwald, Richard M.

    2013-01-01

    Purpose This study aims to quantify the frequency, magnitude, and location of head impacts sustained by male and female collegiate ice hockey players over two seasons of play. Methods Over two seasons, 88 collegiate athletes (51 female, 37 male) on two female and male NCAA varsity ice hockey teams wore instrumented helmets. Each helmet was equipped with 6 single-axis accelerometers and a miniature data acquisition system to capture and record head impacts sustained during play. Data collected from the helmets were post-processed to compute linear and rotational acceleration of the head as well as impact location. The head impact exposure data (frequency, location, and magnitude) were then compared across gender. Results Female hockey players experienced a significantly lower (p < 0.001) number of impacts per athlete exposure than males (female: 1.7 0.7; male: 2.9 1.2). The frequency of impacts by location was the same between gender (p > 0.278) for all locations except the right side of the head, where males received fewer impacts than females (p = 0.031). Female hockey players were 1.1 times more likely than males to sustain an impact less than 50 g while males were 1.3 times more likely to sustain an impact greater than 100 g. Similarly, males were 1.9 times more likely to sustain an impact with peak rotational acceleration greater than 5,000 rad/s2 and 3.5 times more likely to sustain an impact greater than 10,000 rad/s2. Conclusions Although the incidence of concussion has typically been higher for female hockey players than male hockey players, female players sustain fewer impacts and impacts resulting in lower head acceleration than males. Further study is required to better understand the intrinsic and extrinsic risk factors that lead to higher rates of concussion for females that have been previously reported. PMID:21716150

  15. A physical profile of elite female ice hockey players from the USA.

    PubMed

    Ransdell, Lynda B; Murray, Teena

    2011-09-01

    Despite impressive numbers of hockey participants, there is little research examining elite female ice hockey players. Therefore, the purpose of this study was to describe the physical characteristics of elite female ice hockey players who were trying out for the 2010 US Women's Ice Hockey team. Twenty-three women participated in the study and were evaluated for body mass (kilograms), height (centimeters), age (years) vertical jump (centimeters), standing long jump (centimeters), 1RM front squat (kilograms), front squat relative to body mass (percent), 1RM bench press (kilograms), bench press relative to body mass (percent), pull-ups, and body composition (percent body fat). The athletes in this sample were 24.7 years of age (SD = 3.1) and 169.7 cm tall (SD = 6.9); on average, they weighed 70.4 kg (SD = 7.1) and reported 15.8% body fat (SD = 1.9). Mean vertical jump height was 50.3 cm (SD = 5.7) and standing long jump was 214.8 cm (SD = 10.9). Mean 1RM for the upper body strength (bench press) was 65.3 kg (SD = 12.2) (95.1 15.5% of body mass), and 1RM for lower body (front squat) was 88.6 kg (SD = 11.2) (127.7 16.3% of body mass). This study is the first to report the physical characteristics of elite female ice hockey players from the USA. Data should assist strength and conditioning coaches in identifying talent, testing for strengths and weaknesses, comparing future teams to these indicators, and designing programs that will enhance the performance capabilities of female ice hockey athletes. PMID:21804420

  16. The past, present, and future of hockey-stick-shaped liquid crystals

    NASA Astrophysics Data System (ADS)

    Choi, E.-Joon

    2014-02-01

    Recently, the liquid crystalline materials with a bent-core mesogen have attracted attentions because their interesting properties such as polarity and biaxiality of the mesophase. There are several types of bent-core mesogenic structures have been reported, for instance, banana-shaped, V-shaped molecules, boomerang-shaped, hockey stick-shaped, and Yshaped molecules. In this study, the liquid crystals and the reactive mesogens with the hockey-stick shaped mesogens will be described concerning with the structure-property relationship.

  17. Table Hockey: Attack or Linking? Psychoanalytic Psychotherapy with an Autistic Boy

    ERIC Educational Resources Information Center

    Nilsson, May

    2009-01-01

    This paper explores some issues that might arise when one considers having a table hockey game in the therapy room, and describes how an autistic boy, aged four-and-a-half when starting treatment, used that game. The unfolding process from withdrawal to separateness, intersubjectivity and playfulness is illustrated by the progress of two years of

  18. Conservative Treatment of Bilateral Sural Nerve Entrapment in an Ice Hockey Player

    PubMed Central

    Toy, Brian J.

    1996-01-01

    Midway through the season, an intercollegiate ice hockey player experienced bilateral numbness in the posterior aspect of the leg along the area of the calcaneal tendon. This numbness corresponded with the distribution of both sural nerves. While obtaining a history of the condition, the athlete admitted that he routinely spiraled his ice hockey laces tightly around the proximal portion of each ice hockey boot before finally tying the laces off. A complete neurological examination was negative except for the bilateral numbness. Based upon this information, a diagnosis of bilateral sural nerve entrapment was made. In addition to frequent follow-up examinations, nonoperative treatment consisted of changing the way the athlete laced his ice hockey skates. The athlete was able to complete the season and, after approximately 4 months, was asymptomatic. Although this appears to be an isolated incident, athletic trainers should be cautious when evaluating patients with paraesthesia in this region. If symptoms such as those described develop, entrapment of the sural nerve should be considered as a possible cause. ImagesFig 1.Fig 2.Fig 3.Fig 4. PMID:16558377

  19. Checking in: An Analysis of the (Lack of) Body Checking in Women's Ice Hockey

    ERIC Educational Resources Information Center

    Weaving, Charlene; Roberts, Samuel

    2012-01-01

    Despite the growing popularity of women's ice hockey in North America, players continue to face limitations because of the prohibition of body checking. In this paper, we argue from a liberal feminist philosophical perspective that this prohibition reinforces existing traditional stereotypes of female athletes. Because the women's game does not

  20. Receiving Video-Based Feedback in Elite Ice-Hockey: A Player's Perspective

    ERIC Educational Resources Information Center

    Nelson, Lee J.; Potrac, Paul; Groom, Ryan

    2014-01-01

    The aim of this paper was to provide some rich insights into how an elite ice-hockey player responded to his coaches' pedagogical delivery of video-based feedback sessions. Data for this study were gathered through a series of in-depth, semi-structured interviews and a reflective log relating to those interviews. The interviews were

  1. Ice Hockey Players Using a Weighted Implement when Training on the Ice: A Randomized Control Trial

    ERIC Educational Resources Information Center

    Stark, Timothy W.; Tvoric, Bojan; Walker, Bruce; Noonan, Dom; Sibla, Janeene

    2009-01-01

    The purpose of this study was to investigate the potential for improving hockey players' performance using a weighted implement on the ice. Forty-eight players were tested using a grip strength dynamometer. They also were assessed on their abilities to stick-handle. The participants were randomly placed into a control or research group. The

  2. Experiential Learning in the Introductory Class: The Role of Minor League Hockey in Teaching Social Psychology

    ERIC Educational Resources Information Center

    Forrest, Krista D.

    2005-01-01

    To convince my students they are surrounded by social psychology, we attended a minor league hockey game. During the next class period I asked students to write a brief paragraph about their experiences. From those paragraphs I chose four reoccurring themes to analyze from a social psychological perspective. My introductory classes and I benefited

  3. Previous-day hypohydration impairs skill performance in elite female field hockey players.

    PubMed

    MacLeod, H; Sunderland, C

    2012-06-01

    The purpose of this study was to determine the effects of 2% hypohydration on skill performance in elite female field hockey players following intermittent exercise in the heat. Eight elite female field hockey players performed 50 min of a field hockey-specific intermittent treadmill running protocol (FHITP) in hot environmental conditions (33 C, 60% relative humidity) in different hydration states: euhydrated (EUH) and hypohydrated by 2% body mass (HYPO). Hydration status was manipulated via a period (12110 min) of passive hyperthermia (40 C, 75% relative humidity) and controlled fluid intake 1 day preceding testing. Ad libitum fluid intake was permitted throughout both trials. Field hockey skill tests were performed pre- and post-FHITP. Skill performance time increased (P=0.029) in the HYPO trial compared with the EUH trial, which may be attributed to an increase in penalty time (P=0.024). Decision-making time increased (P=0.008) in the HYPO trial and was significantly impaired compared with EUH (P=0.016) pre-FHITP. Ad libitum drinking appeared to be sufficient to maintain decision-making performance as no interaction effects were evident post-FHITP. Players who commence match-play in a state of hypohydration may be susceptible to decrements in skill and decision-making performance. PMID:20973829

  4. Checking in: An Analysis of the (Lack of) Body Checking in Women's Ice Hockey

    ERIC Educational Resources Information Center

    Weaving, Charlene; Roberts, Samuel

    2012-01-01

    Despite the growing popularity of women's ice hockey in North America, players continue to face limitations because of the prohibition of body checking. In this paper, we argue from a liberal feminist philosophical perspective that this prohibition reinforces existing traditional stereotypes of female athletes. Because the women's game does not…

  5. Experiential Learning in the Introductory Class: The Role of Minor League Hockey in Teaching Social Psychology

    ERIC Educational Resources Information Center

    Forrest, Krista D.

    2005-01-01

    To convince my students they are surrounded by social psychology, we attended a minor league hockey game. During the next class period I asked students to write a brief paragraph about their experiences. From those paragraphs I chose four reoccurring themes to analyze from a social psychological perspective. My introductory classes and I benefited…

  6. Table Hockey: Attack or Linking? Psychoanalytic Psychotherapy with an Autistic Boy

    ERIC Educational Resources Information Center

    Nilsson, May

    2009-01-01

    This paper explores some issues that might arise when one considers having a table hockey game in the therapy room, and describes how an autistic boy, aged four-and-a-half when starting treatment, used that game. The unfolding process from withdrawal to separateness, intersubjectivity and playfulness is illustrated by the progress of two years of…

  7. The Control of Externalities in Sports Leagues: An Analysis of Restrictions in the National Hockey League

    ERIC Educational Resources Information Center

    Carlton, Dennis W.; Frankel, Alan S.; Landes, Elisabeth M.

    2004-01-01

    This paper provides one of the few successful demonstrations of the efficiency of certain types of restrictions in the context of a joint venture. The joint venture we examine is the National Hockey League (NHL) in the 1980s, which was then composed of 21 separately owned teams. (It now has 30 teams.) The restriction we analyze is the NHL rule on…

  8. Describing Strategies Used by Elite, Intermediate, and Novice Ice Hockey Referees

    ERIC Educational Resources Information Center

    Hancock, David J.; Ste-Marie, Diane M.

    2014-01-01

    Much is known about sport officials' decisions (e.g., anticipation, visual search, and prior experience). Comprehension of the entire decision process, however, requires an ecologically valid examination. To address this, we implemented a 2-part study using an expertise paradigm with ice hockey referees. Purpose: Study 1 explored the

  9. Selected Field Hockey and Lacrosse Articles. Sports Articles Reprint Series. Third Edition.

    ERIC Educational Resources Information Center

    Stewart, Harriet, Ed.

    This collection of articles from 1964-1970 "Field Hockey-Lacrosse Guides" by the Division for Girls and Women's Sports is the latest in the American Association for Health, Physical Education, and Recreation's "Sports Articles Reprint Series." A special project of the Publications Committee for Girl's and Women's Sports, it is the third edition of

  10. Comparison of Dynamic Balance in Collegiate Field Hockey and Football Players Using Star Excursion Balance Test

    PubMed Central

    Bhat, Rashi; Moiz, Jamal Ali

    2013-01-01

    Purpose The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. Methods A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45 increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. Results There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Conclusion Field hockey players and football players did not differ in terms of dynamic balance. PMID:24427482

  11. The Control of Externalities in Sports Leagues: An Analysis of Restrictions in the National Hockey League

    ERIC Educational Resources Information Center

    Carlton, Dennis W.; Frankel, Alan S.; Landes, Elisabeth M.

    2004-01-01

    This paper provides one of the few successful demonstrations of the efficiency of certain types of restrictions in the context of a joint venture. The joint venture we examine is the National Hockey League (NHL) in the 1980s, which was then composed of 21 separately owned teams. (It now has 30 teams.) The restriction we analyze is the NHL rule on

  12. Receiving Video-Based Feedback in Elite Ice-Hockey: A Player's Perspective

    ERIC Educational Resources Information Center

    Nelson, Lee J.; Potrac, Paul; Groom, Ryan

    2014-01-01

    The aim of this paper was to provide some rich insights into how an elite ice-hockey player responded to his coaches' pedagogical delivery of video-based feedback sessions. Data for this study were gathered through a series of in-depth, semi-structured interviews and a reflective log relating to those interviews. The interviews were…

  13. Ice Hockey Players Using a Weighted Implement when Training on the Ice: A Randomized Control Trial

    ERIC Educational Resources Information Center

    Stark, Timothy W.; Tvoric, Bojan; Walker, Bruce; Noonan, Dom; Sibla, Janeene

    2009-01-01

    The purpose of this study was to investigate the potential for improving hockey players' performance using a weighted implement on the ice. Forty-eight players were tested using a grip strength dynamometer. They also were assessed on their abilities to stick-handle. The participants were randomly placed into a control or research group. The…

  14. Describing Strategies Used by Elite, Intermediate, and Novice Ice Hockey Referees

    ERIC Educational Resources Information Center

    Hancock, David J.; Ste-Marie, Diane M.

    2014-01-01

    Much is known about sport officials' decisions (e.g., anticipation, visual search, and prior experience). Comprehension of the entire decision process, however, requires an ecologically valid examination. To address this, we implemented a 2-part study using an expertise paradigm with ice hockey referees. Purpose: Study 1 explored the…

  15. A PILOT SURVEY ON INJURY AND SAFETY CONCERNS IN INTERNATIONAL SLEDGE HOCKEY

    PubMed Central

    Finlayson, Heather; O'Connor, Russ; Anton, Hugh

    2011-01-01

    Objective: To describe sledge hockey injury patterns, safety issues and to develop potential injury prevention strategies. Design: Pilot survey study of international sledge hockey professionals, including trainers, physiotherapists, physicians, coaches and/or general managers. Setting: Personal encounter or online correspondence. Respondents: Sledge hockey professionals; a total of 10 respondents from the 5 top-ranked international teams recruited by personal encounter or online correspondence. Main Outcome Measurements: Descriptive Data reports on sledge athlete injury characteristics, quality of rules and enforcement, player equipment, challenges in the medical management during competition, and overall safety. Results: Muscle strains and concussions were identified as common, and injuries were reported to affect the upper body more frequently than the lower body. Overuse and body checking were predominant injury mechanisms. Safety concerns included excessive elbowing, inexperienced refereeing and inadequate equipment standards. Conclusions: This paper is the first publication primarily focused on sledge hockey injury and safety. This information provides unique opportunity for the consideration of implementation and evaluation of safety strategies. Safety interventions could include improved hand protection, cut-resistant materials in high-risk areas, increased vigilance to reduce intentional head-contact, lowered rink boards and modified bathroom floor surfacing. PMID:21904696

  16. Trajectories of Affective States in Adolescent Hockey Players: Turning Point and Motivational Antecedents

    ERIC Educational Resources Information Center

    Gaudreau, Patrick; Amiot, Catherine E.; Vallerand, Robert J.

    2009-01-01

    This study examined longitudinal trajectories of positive and negative affective states with a sample of 265 adolescent elite hockey players followed across 3 measurement points during the 1st 11 weeks of a season. Latent class growth modeling, incorporating a time-varying covariate and a series of predictors assessed at the onset of the season,

  17. Explosive Model Tarantula V1/JWL++ Calibration of LX-17: #2

    SciTech Connect

    Souers, P C; Vitello, P

    2009-05-01

    Tarantula V1 is a kinetic package for reactive flow codes that seeks to describe initiation, failure, dead zones and detonation simultaneously. The most important parameter is P1, the pressure between the initiation and failure regions. Both dead zone formation and failure can be largely controlled with this knob. However, V1 does failure with low settings and dead zones with higher settings, so that it cannot fulfill its purpose in the current format. To this end, V2 is under test. The derivation of the initiation threshold P0 is discussed. The derivation of the initiation pressure-tau curve as an output of Tarantula shows that the initiation package is sound. A desensitization package is also considered.

  18. Effectiveness of interventions to reduce aggression and injuries among ice hockey players: a systematic review

    PubMed Central

    Cusimano, Michael D.; Nastis, Sofia; Zuccaro, Laura

    2013-01-01

    Background: The increasing incidence of injuries related to playing ice hockey is an important public health issue. We conducted a systematic review to evaluate the effectiveness of interventions designed to reduce injuries related to aggressive acts in ice hockey. Methods: We identified relevant articles by searching electronic databases from their inception through July 2012, by using Internet search engines, and by manually searching sports medicine journals, the book series Safety in Ice Hockey and reference lists of included articles. We included studies that evaluated interventions to reduce aggression-related injuries and reported ratings of aggressive behaviour or rates of penalties or injuries. Results: We identified 18 eligible studies. Most involved players in minor hockey leagues. Of 13 studies that evaluated changes in mandatory rules intended to lessen aggression (most commonly the restriction of body-checking), 11 observed a reduction in penalty or injury rates associated with rule changes, and 9 of these showed a statistically significant decrease. The mean number of penalties decreased by 1.25.9 per game, and injury rates decreased 3- to 12-fold. All 3 studies of educational interventions showed a reduction in penalty rates, but they were not powered or designed to show a change in injury rates. In 2 studies of cognitive behavioural interventions, reductions in aggressive behaviours were observed. Interpretation: Changes to mandatory rules were associated with reductions in penalties for aggressive acts and in injuries related to aggression among ice hockey players. Effects of educational and cognitive behavioural interventions on injury rates are less clear. Well-designed studies of multifaceted strategies that combine such approaches are required. PMID:23209118

  19. Caffeinated Energy Drinks Improve High-Speed Running in Elite Field Hockey Players.

    PubMed

    Del Coso, Juan; Portillo, Javier; Salinero, Juan José; Lara, Beatriz; Abian-Vicen, Javier; Areces, Francisco

    2016-02-01

    The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink to improve physical performance of elite field hockey players during a game. On 2 days separated by a week, 13 elite field hockey players (age and body mass = 23.2 ± 3.9 years and 76.1 ± 6.1 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 min for caffeine absorption, participants played a simulated field hockey game (2 × 25 min). Individual running pace and instantaneous speed during the game were assessed using GPS devices. The total number of accelerations and decelerations was determined by accelerometry. Compared with the placebo drink, the caffeinated energy drink did not modify the total distance covered during the game (6,035 ± 451 m and 6,055 ± 499 m, respectively; p = .87), average heart rate (155 ± 13 beats per min and 158 ± 18 beats per min, respectively; p = .46), or the number of accelerations and decelerations (697 ± 285 and 618 ± 221, respectively; p = .15). However, the caffeinated energy drink reduced the distance covered at moderate-intensity running (793 ± 135 and 712 ± 116, respectively; p = .03) and increased the distance covered at high-intensity running (303 ± 67 m and 358 ± 117 m; p = .05) and sprinting (85 ± 41 m and 117 ± 55 m, respectively; p = .02). Elite field hockey players can benefit from ingesting caffeinated energy drinks because they increase the running distance covered at high-intensity running and sprinting. Increased running distance at high speed might represent a meaningful advantage for field hockey performance. PMID:26251550

  20. The Protective Effect of Kevlar Socks Against Hockey Skate Blade Injuries: A Biomechanical Study

    PubMed Central

    Nauth, Aaron; Aziz, Mina; Tsuji, Matthew; Whelan, Daniel B.; Theodoropoulos, John S.; Zdero, Rad

    2014-01-01

    Objectives: Several recent high profile injuries to elite players in the National Hockey League (NHL) secondary to skate blade lacerations have generated significant interest in these injuries and possible methods to protect against them. These injuries are typically due to direct contact of the skate blade of another player with posterior aspect of the calf resulting in a range of potential injuries to tendons or neurovascular structures. The Achilles tendon is most commonly involved. Kevlar reinforced socks have recently become available for hockey players to wear and are cited as providing possible protection against such injuries. However, there has been no investigation of the possible protective effects of Kevlar reinforced socks against skate blade injuries, and it is currently unknown what protective effects, if any, that these socks provide against these injuries. The proposed study sought to address this by conducting a biomechanical investigation of the protective effects of Kevlar reinforced socks against Achilles tendon injuries in a simulated model of skate blade injury using human cadaver limbs. This novel investigation is the first to address the possible benefits to hockey players of wearing Kevlar reinforced socks. Methods: Seven matched pairs of human cadaver lower limbs were fitted with a Kevlar reinforced sock comprised of 60% Kevlar/20% Coolmax polyester/18 % Nylon/12% Spandex (Bauer Elite Performance Skate Sock) on one limb and a standard synthetic sock comprised of 51% polyester/47% nylon/2% spandex (Bauer Premium Performance Skate Sock) on the contralateral limb as a control. Each limb was then mounted on a Materials Testing System (MTS) with the ankle dorsiflexed to 90 and the knee held in full extension using a custom designed jig. Specimens were then impacted with a hockey skate blade directed at the posterior calf, 12 cm above the heel, at an angle of 45 and a speed of 31m/s, to a penetration depth of 4.3 cm, to simulate a typical ice hockey injury. Peak force, energy and power were calculated from the force-displacement data collected from the 7 matched pair trials. The cadavers were then dissected to identify the extent of the injury the skin and Achilles tendon from blade impact. Analysis of variance was used to test for a significant difference between the groups. Results: None (0/7) of the achilles tendons were lacerated when protected with Kevlar reinforced socks; whereas all (7/7) achilles tendons tested using the standard synthetic sock were completely severed (Figure 1). Peak force (4030 +/- 1191 N vs. 2037 +/- 729 N), energy (81.4 +/- 38.9 J vs. 26.3 +/- 13.2 J) and power (471.2 +/- 166.7 W vs. 258.3 +/- 93.5 W) were all significantly (p<0.05) increased in the Kevlar reinforced sock group compared to the standard synthetic sock group in our testing model (Figures 2 and 3). Conclusion: The Kevlar reinforced socks provided significantly more cut resistance and were able to withstand a significantly larger peak force, energy and power from skate blade impact and prevent achilles tendon laceration when compared to standard synthetic hockey socks in a biomechanical testing model using human cadaver limbs. This is the first investigation to address the benefits of wearing Kevlar reinforced hockey socks in a simulated model of hockey skate injuries and our results suggest a significant protective effect from the use of Kevlar reinforced socks against hockey skate injuries.

  1. Biomechanics of head impacts associated with diagnosed concussion in female collegiate ice hockey players.

    PubMed

    Wilcox, Bethany J; Beckwith, Jonathan G; Greenwald, Richard M; Raukar, Neha P; Chu, Jeffrey J; McAllister, Thomas W; Flashman, Laura A; Maerlender, Arthur C; Duhaime, Ann-Christine; Crisco, Joseph J

    2015-07-16

    Epidemiological evidence suggests that female athletes may be at a greater risk of concussion than their male counterparts. The purpose of this study was to examine the biomechanics of head impacts associated with diagnosed concussions in a cohort of female collegiate ice hockey players. Instrumented helmets were worn by 58 female ice hockey players from 2 NCAA programs over a three year period. Kinematic measures of single impacts associated with diagnosed concussion and head impact exposure on days with and without diagnosed concussion were evaluated. Nine concussions were diagnosed. Head impact exposure was greater in frequency and magnitude on days of diagnosed concussions than on days without diagnosed concussion for individual athletes. Peak linear accelerations of head impacts associated with diagnosed concussion in this study are substantially lower than those previously reported in male athletes, while peak rotational accelerations are comparable. Further research is warranted to determine the extent to which female athletes' biomechanical tolerance to concussion injuries differs from males. PMID:25913243

  2. In-game fatigue influences concussions in national hockey league players.

    PubMed

    Stevens, Sean T; Lassonde, Maryse; de Beaumont, Louis; Keenan, Julian Paul

    2008-01-01

    The number of concussions and other head injuries are increasing in the National Hockey League (NHL). The factors that may influence concussion risk in hockey remain largely unknown. In the current study, data on 787 NHL players from the 2001-2002 season were examined. It was found that a player's average ice time per game was a significant predictor of concussion. A player's total ice time for the season was not a significant predictor, however, and there was no significant difference found in the number of games played in the season between those who suffered a concussion and those who did not. These data suggest that in-game fatigue is an important factor when considering concussions. PMID:18373290

  3. Poor peak dorsiflexor torque associated with incidence of ankle injury in elite field female hockey players.

    PubMed

    Naicker, Marlene; McLean, Michelle; Esterhuizen, Tonya M; Peters-Futre, Edith M

    2007-12-01

    This study set out to determine the incidence of ankle injuries amongst provincial female field hockey players in KwaZulu-Natal (KZN), South Africa, during the 2004 field hockey season and relate this to their injury and playing profile, proprioceptive ability and peak isokinetic torque of the ankle plantar and dorsiflexor muscles. Players participating in the senior, U21 and U19/high school provincial A teams (n=47) detailed their hockey playing and training history and injuries sustained during the 2004 season. A subsample of injured and matched, uninjured controls (n=18) underwent anthropometric, proprioceptive and isokinetic testing. Incidence of injury in the 2004 season was 0.98 per player or 6.32 injuries per 1000 player/h(-1), with 25.5% of players (n=12) reporting injuries to the ankle joint. All ankle injuries occurred on artificial turf and 75% occurred during a match. Forwards and links that had been playing for six to seven years presented with the highest incidence of ankle injuries. Injured players were able to maintain balance on a proprioceptive board for 10.31+/-8.2 s versus 23.9+/-15.3 s in matched, uninjured controls (p=0.078). Both mean (27.4+/-5.5 Nm versus 32.7+/-4.7 Nm) and median (27.0, 23.0-31.5 versus 31.8, 30.0-35.1 Nm) peak isokinetic torque of the dorsiflexors of injured legs was significantly lower than in uninjured, contralateral legs of the injured players (p=0.01 and 0.03, respectively). Poor peak dorsiflexion torque in the injured leg was identified as a factor associated with ankle injury in this sample of injured, elite field hockey players. PMID:17560829

  4. Trends in North American newspaper reporting of brain injury in ice hockey.

    PubMed

    Cusimano, Michael D; Sharma, Bhanu; Lawrence, David W; Ilie, Gabriela; Silverberg, Sarah; Jones, Rochelle

    2013-01-01

    The frequency and potential long-term effects of sport-related traumatic brain injuries (TBI) make it a major public health concern. The culture within contact sports, such as ice hockey, encourages aggression that puts youth at risk of TBI such as concussion. Newspaper reports play an important role in conveying and shaping the culture around health-related behaviors. We qualitatively studied reports about sport-related TBI in four major North American newspapers over the last quarter-century. We used the grounded-theory approach to identify major themes and then did a content analysis to compare the frequency of key themes between 1998-2000 and 2009-2011. The major themes were: perceptions of brain injury, aggression, equipment, rules and regulations, and youth hockey. Across the full study period, newspaper articles from Canada and America portrayed violence and aggression that leads to TBI both as integral to hockey and as an unavoidable risk associated with playing the game. They also condemned violence in ice hockey, criticized the administrative response to TBI, and recognized the significance of TBI. In Canada, aggression was reported more often recently and there was a distinctive shift in portraying protective equipment as a solution to TBI in earlier years to a potential contributing factor to TBI later in the study period. American newspapers gave a greater attention to 'perception of risks' and the role of protective equipment, and discussed TBI in a broader context in the recent time period. Newspapers from both countries showed similar recent trends in regards to a need for rule changes to curb youth sport-related TBI. This study provides a rich description of the reporting around TBI in contact sport. Understanding this reporting is important for evaluating whether the dangers of sport-related TBI are being appropriately communicated by the media. PMID:23613957

  5. Oculomotor and neurocognitive assessment of youth ice hockey players: baseline associations and observations after concussion.

    PubMed

    Vernau, Brian T; Grady, Matthew F; Goodman, Arlene; Wiebe, Douglas J; Basta, Luke; Park, Yong; Arbogast, Kristy B; Master, Christina L

    2015-01-01

    Baseline scores on the King-Devick (K-D) Test, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Sport Concussion Assessment Tool 3 (SCAT3), and convergence were evaluated in youth hockey players. Worse K-D times were associated with worse ImPACT visual motor speed and reaction time. Eleven concussed athletes were retested, and there was a trend toward improved ImPACT and K-D times compared to baseline. PMID:25649773

  6. Trends in North American Newspaper Reporting of Brain Injury in Ice Hockey

    PubMed Central

    Cusimano, Michael D.; Sharma, Bhanu; Lawrence, David W.; Ilie, Gabriela; Silverberg, Sarah; Jones, Rochelle

    2013-01-01

    The frequency and potential long-term effects of sport-related traumatic brain injuries (TBI) make it a major public health concern. The culture within contact sports, such as ice hockey, encourages aggression that puts youth at risk of TBI such as concussion. Newspaper reports play an important role in conveying and shaping the culture around health-related behaviors. We qualitatively studied reports about sport-related TBI in four major North American newspapers over the last quarter-century. We used the grounded-theory approach to identify major themes and then did a content analysis to compare the frequency of key themes between 19982000 and 20092011. The major themes were: perceptions of brain injury, aggression, equipment, rules and regulations, and youth hockey. Across the full study period, newspaper articles from Canada and America portrayed violence and aggression that leads to TBI both as integral to hockey and as an unavoidable risk associated with playing the game. They also condemned violence in ice hockey, criticized the administrative response to TBI, and recognized the significance of TBI. In Canada, aggression was reported more often recently and there was a distinctive shift in portraying protective equipment as a solution to TBI in earlier years to a potential contributing factor to TBI later in the study period. American newspapers gave a greater attention to perception of risks and the role of protective equipment, and discussed TBI in a broader context in the recent time period. Newspapers from both countries showed similar recent trends in regards to a need for rule changes to curb youth sport-related TBI. This study provides a rich description of the reporting around TBI in contact sport. Understanding this reporting is important for evaluating whether the dangers of sport-related TBI are being appropriately communicated by the media. PMID:23613957

  7. An on-ice aerobic maximal multistage shuttle skate test for elite adolescent hockey players.

    PubMed

    Leone, M; Lger, L A; Larivire, G; Comtois, A S

    2007-10-01

    The aim of this study was to design an on-ice test to predict V.O (2max) in ice hockey players. 30 elite hockey players (age 14.7 +/- 1.5 years) participated in this study. The oxygen uptake was assessed at submaximal and maximal velocities during an on-ice intermittent maximal multistage shuttle skate test with a 1-min/0.5-min work/rest ratio. The procedure consisted of skating back and forth on a distance of 45 m (stop and go) while following a pace fixed by an audible signal: initial velocity of 3.5 m . s (-1) with increments of 0.2 m . s (-1) every stage. The skating multistage aerobic test (SMAT) enabled the prediction of the V.O (2max) (ml . kg (-1) . min (-1)) from the maximal velocity (m . s (-1)) by means of the following regression equation: V.O (2max) = 18.07 x (maximal velocity) - 35.596 (r = 0.97, SEE = 3.01). The test-retest correlation was 0.92 and SEE = 0.56 stage (n = 23). Following the SMAT validation, an additional group of 112 elite male (age = 14.2 +/- 1.3 years) and 31 elite female (age = 14.0 +/- 1.2 years) ice hockey players performed both the 20-m shuttle run test and the SMAT, which was more specific and accurate to predict V.O (2max). The overall results suggest that the SMAT is highly specific, valid and reliable for the prediction of V.O (2max) of ice hockey players. PMID:17534782

  8. An On-Ice Measurement Approach to Analyse the Biomechanics of Ice Hockey Skating

    PubMed Central

    Buckeridge, Erica; LeVangie, Marc C.; Stetter, Bernd; Nigg, Sandro R.; Nigg, Benno M.

    2015-01-01

    Skating is a fundamental movement in ice hockey; however little research has been conducted within the field of hockey skating biomechanics due to the difficulties of on-ice data collection. In this study a novel on-ice measurement approach was tested for reliability, and subsequently implemented to investigate the forward skating technique, as well as technique differences across skill levels. Nine high caliber (High) and nine low caliber (Low) hockey players performed 30m forward skating trials. A 3D accelerometer was mounted to the right skate for the purpose of stride detection, with the 2nd and 6th strides defined as acceleration and steady-state, respectively. The activity of five lower extremity muscles was recorded using surface electromyography. Biaxial electro-goniometers were used to quantify hip and knee angles, and in-skate plantar force was measured using instrumented insoles. Reliability was assessed with the coefficient of multiple correlation, which demonstrated moderate (r>0.65) to excellent (r>0.95) scores across selected measured variables. Greater plantar-flexor muscle activity and hip extension were evident during acceleration strides, while steady state strides exhibited greater knee extensor activity and hip abduction range of motion (p<0.05). High caliber exhibited greater hip range of motion and forefoot force application (p<0.05). The successful implementation of this on-ice mobile measurement approach offers potential for athlete monitoring, biofeedback and training advice. PMID:25973775

  9. Penalty corner routines in elite women's indoor field hockey: prediction of outcomes based on tactical decisions.

    PubMed

    Vinson, Don; Padley, Simon; Croad, Alison; Jeffreys, Mark; Brady, Abbe; James, David

    2013-01-01

    Indoor hockey is a highly competitive international sport, yet no research to date has investigated the key actions within this sport. As with outdoor field hockey, penalty corners represent one of the most likely situations in which goals can be scored. All 36 matches of the round-robin phase of the 2010-2011 England Hockey League Women's Premier Division 'Super Sixes' competition were analysed with the purpose of establishing which factors can predict the scoring of a goal using binary logistic regression analysis. Seventy-two (22.6%) of the 319 observed penalty corners resulted in a goal. The strongest predictor of scoring a goal was taking the penalty corner from the goalkeeper's right. Based on the odds ratio (OR), the odds of the attacking team scoring were 2.27 (confidence interval (CI) = 1.41-3.65) times higher with penalty corners taken from the goalkeeper's right as opposed to the left. Additionally, if the goalkeeper decided to rush to the edge of the circle, the odds of the attacking team failing to score were 2.19 (CI = 1.18-4.08) times higher compared to when the goalkeeper remained near the goal line. These results suggest that strategic decisions from the players and coaches have an important part to play in the success of penalty corners. Future research should investigate the impact of goalkeepers' movement and further examine the technical and tactical intricacies of penalty corners. PMID:23305340

  10. Training-induced changes in drag-flick technique in female field hockey players.

    PubMed

    de Subijana, C L; Gmez, M; Martn-Casado, L; Navarro, E

    2012-12-01

    The penalty corner is one of the most important goal plays in field hockey. The drag-flick is used less by women than men in a penalty corner. The aim of this study was to describe training-induced changes in the drag-flick technique in female field hockey players. Four female players participated in the study. The VICON optoelectronic system (Oxford Metrics, Oxford, UK) measured the kinematic parameters of the drag-flick with six cameras sampling at 250 Hz, prior to and after training. Fifteen shots were captured for each subject. A Wilcoxon test assessed the differences between pre-training and post-training parameters. Two players received specific training twice a week for 8 weeks; the other two players did not train. The proposed drills improved the position of the stick at the beginning of the shot (p < 0.05), the total distance of the shot (p < 0.05) and the rotation radius at ball release (p < 0.01). It was noted that all players had lost speed of the previous run. Further studies should include a larger sample, in order to provide more information on field hockey performance. PMID:24868116

  11. TRAINING-INDUCED CHANGES IN DRAG-FLICK TECHNIQUE IN FEMALE FIELD HOCKEY PLAYERS

    PubMed Central

    Gmez, M.; Martn-Casado, L.; Navarro, E.

    2012-01-01

    The penalty corner is one of the most important goal plays in field hockey. The drag-flick is used less by women than men in a penalty corner. The aim of this study was to describe training-induced changes in the drag-flick technique in female field hockey players. Four female players participated in the study. The VICON optoelectronic system (Oxford Metrics, Oxford, UK) measured the kinematic parameters of the drag-flick with six cameras sampling at 250 Hz, prior to and after training. Fifteen shots were captured for each subject. A Wilcoxon test assessed the differences between pre-training and post-training parameters. Two players received specific training twice a week for 8 weeks; the other two players did not train. The proposed drills improved the position of the stick at the beginning of the shot (p < 0.05), the total distance of the shot (p < 0.05) and the rotation radius at ball release (p < 0.01). It was noted that all players had lost speed of the previous run. Further studies should include a larger sample, in order to provide more information on field hockey performance. PMID:24868116

  12. A 26 year physiological description of a National Hockey League team.

    PubMed

    Quinney, H A; Dewart, Randy; Game, Alex; Snydmiller, Gary; Warburton, Darren; Bell, Gordon

    2008-08-01

    The primary purpose of this investigation was to examine the physiological profile of a National Hockey League (NHL) team over a period of 26 years. All measurements were made at a similar time of year (pre-season) in 703 male (mean age +/- SD = 24 +/- 4 y) hockey players. The data were analyzed across years, between positions (defensemen, forwards, and goaltenders), and between what were deemed successful and non-successful years using a combination of points acquired during the season and play-off success. Most anthropometric (height, mass, and BMI) and physiological parameters (absolute and relative VO2 peak, relative peak 5 s power output, abdominal endurance, and combined grip strength) showed a gradual increase over the 26 year period. Defensemen were taller and heavier, had higher absolute VO2 peak, and had greater combined grip strength than forwards and goaltenders. Forwards were younger and had higher values for relative VO2 peak. Goaltenders were shorter, had less body mass, a higher sum of skinfolds, lower VO2 peak, and better flexibility. The overall pre-season fitness profile was not related to team success. In conclusion, this study revealed that the fitness profile for a professional NHL ice-hockey team exhibited increases in player size and anaerobic and aerobic fitness parameters over a 26 year period that differed by position. However, this evolution of physiological profile did not necessarily translate into team success in this particular NHL franchise. PMID:18641719

  13. Development of hydroacoustical techniques for the monitoring and classification of benthic habitats in Puck Bay: Modeling of acoustic waves scattering by seagrass

    NASA Astrophysics Data System (ADS)

    Raczkowska, A.; Gorska, N.

    2012-12-01

    Puck Bay is an area of high species biodiversity belonging to the Coastal Landscape Park of Baltic Sea Protected Areas (BSPA) and is also included in the list of the World Wide Fund for Nature (WWF) and covered by the protection program "Natura 2000". The underwater meadows of the Puck Bay are important for Europe's natural habitats due to their role in enhancing the productivity of marine ecosystems and providing shelter and optimal feeding conditions for many marine organisms. One of the dominant species comprising the underwater meadows of the Southern Baltic Sea is the seagrass Zostera marina. The spatial extent of underwater seagrass meadows is altered by pollution and eutrophication; therefore, to properly manage the area one must monitor its ecological state. Remote acoustic methods are useful tools for the monitoring of benthic habitats in many marine areas because they are non-invasive and allow researchers to obtain data from a large area in a short period of time. Currently there is a need to apply these methods in the Baltic Sea. Here we present an analysis of the mechanism of scattering of acoustic waves on seagrass in the Southern Baltic Sea based on the numerical modeling of acoustic wave scattering by the biological tissues of plants. The study was conducted by adapting a model developed on the basis of DWBA (Distorted Wave Born Approximation) developed by Stanton and Chu (2005) for fluid-like objects, including the characteristics of the Southern Baltic seagrass. Input data for the model, including the morphometry of seagrass leaves, their angle of inclination and the density plant cover, was obtained through the analysis of biological materials collected in the Puck Bay in the framework of a research project financed by the Polish Government (Development of hydroacoustic methods for studies of underwater meadows of Puck Bay, 6P04E 051 20). On the basis of the developed model, we have analyzed the dependence of the target strength of a single seagrass leaf and the strength of surface scattering from the orientation of the leaves relative to the direction of incidence of the acoustic wave. The influences of the acoustic properties of the biological plant tissue and acoustic frequency were also examined in regards to these dependencies. It was found that the target strength of the seagrass leaf depends on the angle of inclination relative to the direction of incidence of the acoustic wave; furthermore, target strength was found to be sensitive to the frequency of the wave and the value of density and speed sound contrasts. These parameters also affect the nature of the oscillations depending on the target strenght to the angle of inclination of sea grass leaves. We have also performed a prognosis of surface scattering strength variability for sea grass meadows of Zostera marina in Puck Bay. The results obtained in this study are important for interpretation of acoustic measurements carried out in the underwater meadows of Puck Bay. Thus, they contribute to the development of non-invasive and fast acoustic monitoring methods.

  14. Risk of injury associated with bodychecking experience among youth hockey players

    PubMed Central

    Emery, Carolyn; Kang, Jian; Shrier, Ian; Goulet, Claude; Hagel, Brent; Benson, Brian; Nettel-Aguirre, Alberto; McAllister, Jenelle; Meeuwisse, Willem

    2011-01-01

    Background: In a previous prospective study, the risk of concussion and all injury was more than threefold higher among Pee Wee ice hockey players (ages 1112 years) in a league that allows bodychecking than among those in a league that does not. We examined whether two years of bodychecking experience in Pee Wee influenced the risk of concussion and other injury among players in a Bantam league (ages 1314) compared with Bantam players introduced to bodychecking for the first time at age 13. Methods: We conducted a prospective cohort study involving hockey players aged 1314 years in the top 30% of divisions of play in their leagues. Sixty-eight teams from the province of Alberta (n = 995), whose players had two years of bodychecking experience in Pee Wee, and 62 teams from the province of Quebec (n = 976), whose players had no bodychecking experience in Pee Wee, participated. We estimated incidence rate ratios (IRRs) for injury and for concussion. Results: There were 272 injuries (51 concussions) among the Bantam hockey players who had bodychecking experience in Pee Wee and 244 injuries (49 concussions) among those without such experience. The adjusted IRRs for game-related injuries and concussion overall between players with bodychecking experience in Pee Wee and those without it were as follows: injury overall 0.85 (95% confidence interval [CI] 0.63 to 1.16); concussion overall 0.84 (95% CI 0.48 to 1.48); and injury resulting in more than seven days of time loss (i.e., time between injury and return to play) 0.67 (95% CI 0.46 to 0.99). The unadjusted IRR for concussion resulting in more than 10 days of time loss was 0.60 (95% CI 0.26 to 1.41). Interpretation: The risk of injury resulting in more than seven days of time loss from play was reduced by 33% among Bantam hockey players in a league where bodychecking was allowed two years earlier in Pee Wee compared with Bantam players introduced to bodychecking for the first time at age 13. In light of the increased risk of concussion and other injury among Pee Wee players in a league where bodychecking is permitted, policy regarding the age at which hockey players are introduced to bodychecking requires further consideration. PMID:21690221

  15. A Novel Approach to Determine Strides, Ice Contact, and Swing Phases During Ice Hockey Skating Using a Single Accelerometer.

    PubMed

    Stetter, Bernd J; Buckeridge, Erica; von Tscharner, Vinzenz; Nigg, Sandro R; Nigg, Benno M

    2016-02-01

    This study presents a new approach for automated identification of ice hockey skating strides and a method to detect ice contact and swing phases of individual strides by quantifying vibrations in 3D acceleration data during the blade-ice interaction. The strides of a 30-m forward sprinting task, performed by 6 ice hockey players, were evaluated using a 3D accelerometer fixed to a hockey skate. Synchronized plantar pressure data were recorded as reference data. To determine the accuracy of the new method on a range of forward stride patterns for temporal skating events, estimated contact times and stride times for a sequence of 5 consecutive strides was validated. Bland-Altman limits of agreement (95%) between accelerometer and plantar pressure derived data were less than 0.019 s. Mean differences between the 2 capture methods were shown to be less than 1 ms for contact and stride time. These results demonstrate the validity of the novel approach to determine strides, ice contact, and swing phases during ice hockey skating. This technology is accurate, simple, effective, and allows for in-field ice hockey testing. PMID:26398967

  16. Face-off in Minnesota. A Pilot Study of Girls' Ice Hockey Experience during the First Year of State High School League-Sanctioned Play.

    ERIC Educational Resources Information Center

    Ehlinger, Sally; Katz, Jennifer L.

    1995-01-01

    Reports a study that analyzed high school girls' experiences as they established ice hockey as a competitive girls' sport. Surveys of the social, psychological, and skill aspects of their experiences indicated high enthusiasm and determination levels, with 80% of them definitely planning to continue playing ice hockey. (SM)

  17. The effects of undergarment composition worn beneath hockey protective equipment on high-intensity intermittent exercise.

    PubMed

    Noonan, Benjamin; Stachenfeld, Nina

    2012-09-01

    The purpose of this study was to examine the impact of undergarment composition worn beneath ice hockey protective equipment on thermal homeostasis and power output, during a cycle ergometer exercise protocol designed to simulate the energy expenditure of a hockey game. We hypothesized that the layers of protective equipment would negate the potential thermoregulatory benefits from synthetic "wicking" undergarments but that subjects may feel more comfortable because of the inherent low moisture retention of these fabrics. Eight men (age, 25.4 1.3 year) performed a repeated sprint test before and after a simulated game under typical hockey conditions (12C; 82% relative humidity). This test was completed twice while wearing full protective equipment and either synthetic (SYN) or cotton (COT) full-length undergarments. During the simulated game, skin temperatures (34.22 0.20C vs. 34.46 0.16C) and core temperatures (37.50 0.13C vs. 37.59 0.14C) were similar between SYN and COT, respectively. There were also no significant differences found in sweat loss as a percent of body mass, heart rate, plasma lactate, sprint power, or ratings of perceived exertion between SYN and COT, respectively. The SYN retained less water than COT (140 30 vs. 310 30 g; p < 0.05); however, clothing and protective equipment weight gains as a whole were unaffected by the fabric worn (470 110 vs. 590 80 g) for SYN and COT, respectively. There were minimal differences in thermal sensation and undergarment wetness ratings during the simulated game. Thermoregulation and performance was driven more by properties of the layered protective equipment with minimal effects from undergarment composition. PMID:22706578

  18. The Impact of a Sports Vision Training Program in Youth Field Hockey Players

    PubMed Central

    Schwab, Sebastian; Memmert, Daniel

    2012-01-01

    The aim of this study was to investigate whether a sports vision training program improves the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training. The choice reaction time task at the D2 board (Learning Task I), the functional field of view task (Learning Task II) and the multiple object tracking (MOT) task (Transfer Task) were assessed before and after the intervention and again six weeks after the second test. Analyzes showed significant differences between the two groups for the choice reaction time task at the D2 board and the functional field of view task, with significant improvements for the intervention group and none for the control group. For the transfer task, we could not find statistically significant improvements for either group. The results of this study are discussed in terms of theoretical and practical implications. Key pointsPerceptual training with youth field hockey playersCan a sports vision training program improve the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training?The intervention was performed in the “VisuLab” as DynamicEye® SportsVision Training at the German Sport University Cologne.We ran a series of 3 two-factor univariate analysis of variance (ANOVA) with repeated measures on both within subject independent variables (group; measuring point) to examine the effects on central perception, peripheral perception and choice reaction time.The present study shows an improvement of certain visual abilities with the help of the sports vision training program. PMID:24150071

  19. THE ROLE OF AEROBIC CAPACITY IN HIGH-INTENSITY INTERMITTENT EFFORTS IN ICE-HOCKEY

    PubMed Central

    Roczniok, R.; Maszczyk, A.; Pietraszewski, P.; Zaj?c, A.

    2014-01-01

    The primary objective of this study was to determine a relationship between aerobic capacity (V.O2max) and fatigue from high-intensity skating in elite male hockey players. The subjects were twenty-four male members of the senior national ice hockey team of Poland who played the position of forward or defence. Each subject completed an on-ice Repeated-Skate Sprint test (RSS) consisting of 6 timed 89-m sprints, with 30 s of rest between subsequent efforts, and an incremental test on a cycle ergometer in the laboratory, the aim of which was to establish their maximal oxygen uptake (V.O2max). The analysis of variance showed that each next repetition in the 6x89 m test was significantly longer than the previous one (F5,138=53.33, p<0.001). An analysis of the fatigue index (FI) calculated from the times recorded for subsequent repetitions showed that the value of the FI increased with subsequent repetitions, reaching its maximum between repetitions 5 and 6 (3.101.16%). The total FI was 13.771.74%. The coefficient of correlation between V.O2max and the total FI for 6 sprints on the distance of 89 m (r =0.584) was significant (p=0.003). The variance in the index of players fatigue in the 6x89 m test accounted for 34% of the variance in V.O2max. The 6x89 m test proposed in this study offers a high test-retest correlation coefficient (r=0.78). Even though the test is criticized for being too exhaustive and thereby for producing highly variable results it still seems that it was well selected for repeated sprint ability testing in hockey players. PMID:25177097

  20. The impact of a sports vision training program in youth field hockey players.

    PubMed

    Schwab, Sebastian; Memmert, Daniel

    2012-01-01

    The aim of this study was to investigate whether a sports vision training program improves the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training. The choice reaction time task at the D2 board (Learning Task I), the functional field of view task (Learning Task II) and the multiple object tracking (MOT) task (Transfer Task) were assessed before and after the intervention and again six weeks after the second test. Analyzes showed significant differences between the two groups for the choice reaction time task at the D2 board and the functional field of view task, with significant improvements for the intervention group and none for the control group. For the transfer task, we could not find statistically significant improvements for either group. The results of this study are discussed in terms of theoretical and practical implications. Key pointsPerceptual training with youth field hockey playersCan a sports vision training program improve the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training?The intervention was performed in the "VisuLab" as DynamicEye() SportsVision Training at the German Sport University Cologne.We ran a series of 3 two-factor univariate analysis of variance (ANOVA) with repeated measures on both within subject independent variables (group; measuring point) to examine the effects on central perception, peripheral perception and choice reaction time.The present study shows an improvement of certain visual abilities with the help of the sports vision training program. PMID:24150071

  1. Planets and Pucks.

    ERIC Educational Resources Information Center

    Brueningsen, Christopher; Krawiec, Wesley

    1993-01-01

    Presents a simple activity designed to allow students to experimentally verify Kepler's second law, sometimes called the law of equal areas. It states that areas swept out by a planet as it orbits the Sun are equal for equal time intervals. (PR)

  2. Bebop on the Hockey Pitch: Cross-Disciplinary Creativity and Skills Transfer

    PubMed Central

    Harrison, Clive M.

    2016-01-01

    This paper generalizes task-specific (but dissimilar) skills, from the jazz concert stage and from the hockey field, into the domain of creativity research. What is sought are clues to what skills or creativities are transferable across dissimilar domains. It is argued that certain domain-general skills are transferable across domains, but a domain-general or ‘c’ creative capacity, is not. Rather than transferring some over-arching capacity to be universally creative, this research highlights factors likely to facilitate successful cross-disciplinary creative expression and posits a correlation between the capacities for discriminant pattern-recognition, task-specific expertise, and sensory data-collection, and the transferability of creativity. Of particular significance is the capacity for informed, selective pattern-breaking based on the ‘depth’ or ‘insider’ perspective of the domain expert; such ‘expert variation and selective retention’ provides creative choices and responses that are likely to be perceived by the field as creative: valuable, novel and surprising. The author is a renowned Australian studio bassist, jazz musician, and music educator who also plays field hockey for Australia at Masters level. His recently completed Ph.D. thesis, based on a performance and composition career spanning 46 years, takes the form of an analytical autoethnography drawn from personal field notes, diaries and interviews as well as published record albums. PMID:26903926

  3. Bebop on the Hockey Pitch: Cross-Disciplinary Creativity and Skills Transfer.

    PubMed

    Harrison, Clive M

    2016-01-01

    This paper generalizes task-specific (but dissimilar) skills, from the jazz concert stage and from the hockey field, into the domain of creativity research. What is sought are clues to what skills or creativities are transferable across dissimilar domains. It is argued that certain domain-general skills are transferable across domains, but a domain-general or 'c' creative capacity, is not. Rather than transferring some over-arching capacity to be universally creative, this research highlights factors likely to facilitate successful cross-disciplinary creative expression and posits a correlation between the capacities for discriminant pattern-recognition, task-specific expertise, and sensory data-collection, and the transferability of creativity. Of particular significance is the capacity for informed, selective pattern-breaking based on the 'depth' or 'insider' perspective of the domain expert; such 'expert variation and selective retention' provides creative choices and responses that are likely to be perceived by the field as creative: valuable, novel and surprising. The author is a renowned Australian studio bassist, jazz musician, and music educator who also plays field hockey for Australia at Masters level. His recently completed Ph.D. thesis, based on a performance and composition career spanning 46 years, takes the form of an analytical autoethnography drawn from personal field notes, diaries and interviews as well as published record albums. PMID:26903926

  4. Skating mechanics of change-of-direction manoeuvres in ice hockey players.

    PubMed

    Fortier, Antoine; Turcotte, Ren A; Pearsall, David J

    2014-11-01

    Ice hockey requires rapid transitions between skating trajectories to effectively navigate about the ice surface. Player performance relates in large part to effective change-of-direction manoeuvres, but little is known about how those skills are performed mechanically and the effect of equipment design on them. The purpose of this study was to observe the kinetics involved in those manoeuvres as well as to compare whether kinetic differences may result between two skate models of varying ankle mobility. Eight subjects with competitive ice hockey playing experience performed rapid lateral (90) left and right change-of-direction manoeuvres. Kinetic data were collected using force strain gauge transducers on the blade holders of the skates. Significantly greater forces were applied by the outside skate (50-70% body weight, %BW) in comparison to the inside skate (12-24%BW, p < 0.05). Skate model and turn direction had no main effect, though significant mixed interactions between leg side (inside/outside) with skate model or turn direction (p < 0.05) were observed, with a trend for left-turn dominance. This study demonstrates the asymmetric dynamic behaviour inherent in skating change-of-direction tasks. PMID:25419626

  5. Practicing Field Hockey Skills Along the Contextual Interference Continuum: A Comparison of Five Practice Schedules

    PubMed Central

    Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J. Robert; Medic, Nikola; Razman, Rizal

    2012-01-01

    To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners. PMID:24149204

  6. Motivational climate, goal orientation, perceived sport ability, and enjoyment within Finnish junior ice hockey players.

    PubMed

    Jaakkola, T; Ntoumanis, N; Liukkonen, J

    2016-01-01

    The aim of this study was to investigate the relations among situational motivational climate, dispositional approach and avoidance achievement goals, perceived sport ability, and enjoyment in Finnish male junior ice hockey players. The sample comprised 265 junior B-level male players with a mean age of 17.03 years (SD = 0.63). Players filled questionnaires tapping their perceptions of coach motivational climate, achievement goals, perceived sport ability, and enjoyment. For the statistical analysis, players were divided into high and low perceived sport ability groups. Multigroup structural equation modeling (SEM) revealed an indirect path from task-involving motivational climate via task-approach goal to enjoyment. Additionally, SEM demonstrated four other direct associations, which existed in both perceived ability groups: from ego-involving motivational climate to ego-approach and ego-avoidance goals; from ego-approach goal to ego-avoidance goal; and from task-avoidance goal to ego-avoidance goal. Additionally, in the high perceived sport ability group, there was an association from task-involving motivational climate to enjoyment. The results of this study reveal that motivational climate emphasizing effort, personal development and improvement, and achievement goal mastering tasks are significant elements of enjoyment in junior ice hockey. PMID:25648198

  7. 1 year test-retest reliability of ImPACT in professional ice hockey players.

    PubMed

    Bruce, Jared; Echemendia, Ruben; Meeuwisse, Willem; Comper, Paul; Sisco, Amber

    2014-01-01

    The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery is widely used to assess neurocognitive outcomes following sports-related concussion. The purpose of this study was to examine the 1 year test-retest reliability of ImPACT in a multilingual sample of professional hockey players. A total of 305 professional hockey players were tested 1 year apart using ImPACT. Reliable change confidence intervals were calculated and test-retest reliability was measured using Pearson and Intraclass correlation coefficients. Results indicated that the 1-year test-retest reliabilities for the Visual Motor and Reaction Time Composites ranged from low to high (.52 to .81). In contrast, 1-year test-retest reliabilities for the Verbal and Visual Memory Composites were low (.22 to .58). The 1-year test-retest results provided mixed support for the use of Visual Motor and Reaction Time Composites in select samples; in contrast, the Verbal and Visual Memory Composites may not be sensitive to clinical change. PMID:24345194

  8. King-Devick test normative reference values for professional male ice hockey players.

    PubMed

    Vartiainen, M V; Holm, A; Peltonen, K; Luoto, T M; Iverson, G L; Hokkanen, L

    2015-06-01

    The King-Devick (K-D) test, a measure of processing speed, visual tracking, and saccadic eye movements, has shown promise as a supplemental screening test following concussion. However, limited normative data for this test have been published.The K-D test was administered to 185 professional ice hockey players as a preseason baseline test in seasons 2012-2013 and 2013-2014. Their average age was 23.8 years (median?=?22.0 years, range?=?16-40 years). The average K-D score was 40.0?s (SD?=?6.1?s, range?=?24.0-65.7?s). K-D test performance showed no association with age, education, or the number of self-reported previous concussions in this sample. The association between trials 1 and 2 of the K-D test was good (ICC?=?0.92, Pearson?=?0.93). Normative values of the K-D test for professional male ice hockey players are reported. K-D test performance did not vary by age, education, or concussion history in this study. PMID:25138698

  9. High-intensity interval training has positive effects on performance in ice hockey players.

    PubMed

    Naimo, M A; de Souza, E O; Wilson, J M; Carpenter, A L; Gilchrist, P; Lowery, R P; Averbuch, B; White, T M; Joy, J

    2015-01-01

    In spite of the well-known benefits that have been shown, few studies have looked at the practical applications of high-intensity interval training (HIIT) on athletic performance. This study investigated the effects of a HIIT program compared to traditional continuous endurance exercise training. 24 hockey players were randomly assigned to either a continuous or high-intensity interval group during a 4-week training program. The interval group (IG) was involved in a periodized HIIT program. The continuous group (CG) performed moderate intensity cycling for 45-60?min at an intensity that was 65% of their calculated heart rate reserve. Body composition, muscle thickness, anaerobic power, and on-ice measures were assessed pre- and post-training. Muscle thickness was significantly greater in IG (p=0.01) when compared to CG. The IG had greater values for both ? peak power (p<0.003) and ? mean power (p<0.02). Additionally, IG demonstrated a faster ? sprint (p<0.02) and a trend (p=0.08) for faster ? endurance test time to completion for IG. These results indicate that hockey players may utilize short-term HIIT to elicit positive effects in muscle thickness, power and on-ice performance. PMID:25329432

  10. Aerobic capacity is associated with improved repeated shift performance in hockey.

    PubMed

    Peterson, Benjamin J; Fitzgerald, John S; Dietz, Calvin C; Ziegler, Kevin S; Ingraham, Stacy J; Baker, Sarah E; Snyder, Eric M

    2015-06-01

    Current research has found conflicting results regarding the relationship between maximal oxygen uptake ((Equation is included in full-text article.)) and the repeated sprint ability (RSA) of hockey players. The purpose of this study was to use sport-specific testing methods to investigate this relationship. Forty-five (range, 18-24) college hockey players completed a graded exercise test on a skating treadmill to ascertain their (Equation is included in full-text article.). An on-ice repeated shift test was then conducted to evaluate each player's susceptibility to fatigue. First gate, second gate, and total test times were collected on the course and then used to calculate associated decrement scores. Second gate decrement was significantly correlated to (Equation is included in full-text article.)(r = -0.31, p = 0.04). Final stage completed during the graded exercise test was also significantly correlated to second gate and total decrement (r = -0.46, p = 0.001; r = -0.32, p = 0.03). No significant correlation was found between either first gate or total decrement score and (Equation is included in full-text article.)(r = -0.11, p = 0.46; r = -0.17, p = 0.26). The results of this study indicate that RSA is associated with (Equation is included in full-text article.)and final stage completed when using sport-specific testing methods. PMID:25756322

  11. I Went to a Fight the Other Night and a Hockey Game Broke Out

    PubMed Central

    Goldschmied, Nadav; Espindola, Samantha

    2013-01-01

    Background: The current study explored the relationship between fighting behavior and passage of time, across games and seasons, in an attempt to assess if violent behavior in hockey is impulsive or intentional. Hypothesis: Before engaging in fighting behavior, players assess the utility of their actions and thus will fight less when the game is on the line (third period) and when champions are crowned (postseason). Methods: An archival exploration utilizing open access databases from multiple Internet sources. Results: During the 2010-2011 National Hockey League (NHL) season, players were significantly less likely to be involved in a fight as the game was coming to a close than in its early stages. In addition, data from the past 10 NHL seasons showed that players were significantly more violent in preseason games than during the regular season. They were also least likely to be involved in a fight during the postseason. Conclusion: The converging evidence suggests that players take into account the penalties associated with fighting and are less likely to engage in violence when the stakes are high, such as at the end of a game or a season. This implies, in turn, that major acts of aggression in the league are more likely to be calculated rather than impulsive. The findings suggest that a more punitive system should diminish fighting behavior markedly. PMID:24427418

  12. Effects of physical training and competition on the iron status of female field hockey players.

    PubMed

    Diehl, D M; Lohman, T G; Smith, S C; Kertzer, R

    1986-10-01

    Female collegiate field hockey players showed decreases in iron stores (as measured by serum ferritin) in each of 3 successive fall seasons studied. After the 1st season of regular play, a decrease (25-23 ng/ml was observed, but measurements after post-season tournament play for the 2nd and 3rd seasons showed significant (P less than 0.05) decreases of 37% (30-19 ng/ml) and 30% (24-17 ng/ml), respectively. The added stress of tournament play appeared to cause additional loss of reserve iron nearly as great as that experienced during early season training. After several years of play, serum ferritin levels in these athletes were frequently between 10 and 20 ng/ml, with the lowest levels occurring in 3rd- and 4th-year athletes. Those women who participated in all 3 years had progressively declining serum ferritin levels throughout their collegiate careers. Participation in collegiate field hockey jeopardizes body iron stores, and iron reserves tend to become progressively more depleted after successive seasons of competition. PMID:3793335

  13. Effects of Carbohydrate Intake Before and During An Ice Hockey Game on Blood and Muscle Energy Substrates.

    ERIC Educational Resources Information Center

    Simard, Clermont; And Others

    1988-01-01

    Study of the effect of a supplemental carbohydrate intake for seven elite ice hockey players before and during a game demonstrated that the supplement could result in less glycogen usage per distance skated, which had important implications for athletes who may participate in more than one game a day. (Author/CB)

  14. Division I Hockey Players Generate More Power Than Division III Players During on- and Off-Ice Performance Tests.

    PubMed

    Peterson, Ben J; Fitzgerald, John S; Dietz, Calvin C; Ziegler, Kevin S; Ingraham, Stacy J; Baker, Sarah E; Snyder, Eric M

    2015-05-01

    Current research has found anthropometric and physiological characteristics of hockey players that are correlated to performance. These characteristics, however, have never been examined to see whether significant differences exist between on- and off-ice performance markers at different levels of play; Division I, Elite Junior, and Division III. The purpose of this study was to examine the differences that may exist between these characteristics in Division I (24), Elite Junior (10), and Division III hockey (11) players. Forty-five (age: 18-24 years) hockey players completed anthropometric, on-ice, and off-ice tests to ascertain average measures for each division of play. On-ice testing was conducted in full hockey gear and consisted of acceleration, top-speed, and on-ice repeated shift test (RST). Off-ice tests included vertical jump, Wingate, grip strength, and a graded exercise test performed on a skating treadmill to ascertain their (Equation is included in full-text article.). Division I players had significantly lower body fat than their Division III peers (p = 0.004). Division I players also scored significantly better on measures of anaerobic power; vertical jump (p = 0.001), Wingate peak power (p = 0.05), grip strength (p = 0.008), top speed (p = 0.001), and fastest RST course time (p = 0.001) than their Division III counterparts. There was no significant difference between Division I and Elite Junior players for any on- or off-ice performance variable. The results of this study indicate that performance differences between Division I and Division III hockey players seem to be primarily because of the rate of force production. PMID:25436625

  15. Seasonal Changes in Whole Body and Regional Body Composition Profiles of Elite Collegiate Ice-Hockey Players.

    PubMed

    Prokop, Neal W; Reid, Ryan E R; Andersen, Ross E

    2016-03-01

    Prokop, NW, Reid, RER, and Andersen, RE. Seasonal changes in whole body and regional body composition profiles of elite collegiate ice-hockey players. J Strength Cond Res 30(3): 684-692, 2016-The monitoring of a collegiate hockey player's body composition can reflect fitness characteristics and may help players, coaches, or strength and conditioning specialists optimize physiologic gains during an off-season, whereas simultaneously preventing performance decrements in-season. The purpose of the study was to investigate changes in whole-body and regional-body composition of fat and lean tissue. The body composition profiles of 19 elite Canadian collegiate hockey players were assessed using dual energy X-ray absorptiometry. Players completed end-of-season, preseason, and midseason assessments with questionnaires relating to their off-season and in-season training. Statistically significant changes in body composition profiles were observed between the different time points because players showed various tissue gains and losses depending on the region assessed. Overall, players gained (1.38 kg, p ≤ 0.01) and lost (0.79 kg, p ≤ 0.01) fat tissue during the off-season and in-season, respectively. Players also showed a significant gain of leg lean tissue (0.29 kg, p = 0.02) and loss of arm tissue mass (-0.25 kg, p = 0.02) during the first-half of the competitive season. Several correlations emerged that may provide insight into potential trends that could be more pronounced during longer and more demanding schedules. Collegiate hockey players show changes in body composition during the off-season and in-season. The understanding of body composition profiles, body composition fluctuations, and potential variables that may influence the composition of collegiate hockey players can help coaches and athletic programs tailor their team's training, nutrition, lifestyle, and informative resources to further support their athletes. PMID:26907839

  16. Effects of badminton and ice hockey on bone mass in young males: a 12-year follow-up.

    PubMed

    Tervo, Taru; Nordstrm, Peter; Nordstrm, Anna

    2010-09-01

    The purpose of the present study was to investigate the influence of different types of weight bearing physical activity on bone mineral density (BMD, g/cm(2)) and evaluate any residual benefits after the active sports career. Beginning at 17 years of age, BMD was measured 5 times, during 12 years, in 19 badminton players, 48 ice hockey players, and 25 controls. During the active career, badminton players gained significantly more BMD compared to ice hockey players at all sites: in their femoral neck (mean difference (Delta) 0.06 g/cm(2), p=0.04), humerus (Delta 0.06 g/cm(2), p=0.01), lumbar spine (Delta 0.08 g/cm(2), p=0.01), and their legs (Delta 0.05 g/cm(2), p=0.003), after adjusting for age at baseline, changes in weight, height, and active years. BMD gains in badminton players were higher also compared to in controls at all sites (Delta 0.06-0.17 g/cm(2), p<0.01 for all). Eleven badminton players and 37 ice hockey players stopped their active career a mean of 6 years before the final follow-up. Both these groups lost significantly more BMD at the femoral neck and lumbar spine compared to the control group (Delta 0.05-0.12 g/cm(2), p<0.05 for all). At the final follow-up, badminton players had significantly higher BMD of the femoral neck, humerus, lumbar spine, and legs (Delta 0.08-0.20 g/cm(2), p<0.01 for all) than both ice hockey players and controls. In summary, the present study may suggest that badminton is a more osteogenic sport compared to ice hockey. The BMD benefits from previous training were partially sustained with reduced activity. PMID:20601297

  17. An examination of the cohesion-performance relationship in university hockey teams.

    PubMed

    Slater, M R; Sewell, D F

    1994-10-01

    The objective of this study was to assess, using the Group Environment Questionnaire, whether team cohesion in university-level field hockey was a cause for, or an effect of, successful performance. A quasi-experimental longitudinal design with cross-lagged correlational analysis was adopted and measures of cohesion and performance were taken midway and later in the season. The results of the synchronous correlations showed a positive relationship (with good stationarity) between team cohesion and performance outcome. Although non-significant cross-lagged differentials indicated a circular relationship, the magnitudes of both the cross-lagged correlations and the partial correlations, together with multiple-regression analyses, revealed that the stronger flow was from cohesion to performance. The socially oriented aspects of cohesion, in particular, had significant associations with performance. The results imply that cohesion-performance relationships should be examined within a circular model, in which cohesion and performance are interdependent. PMID:7799471

  18. The effect of visors on head and facial injury in National Hockey League players.

    PubMed

    Stevens, S T; Lassonde, M; de Beaumont, L; Keenan, J P

    2006-06-01

    There has been an increase in the number of concussions sustained by players in the National Hockey League (NHL). While wearing a helmet is now required by the NHL, the face visor remains optional. It is unknown to what degree face visors influence concussion, other head injury and eye-injury rates at the professional level. Data from the 2001-2002 NHL season were examined. It was found that wearing a face visor did not significantly influence the prevalence of concussion. Visor protection did, however, minimise eye-injuries and other, non-concussion head injuries. These data suggest that, while a visor may prevent some head and eye-injuries, other measures may be necessary to reduce the number of concussions. PMID:16716662

  19. Stages and demands in the careers of Canadian National Hockey League players.

    PubMed

    Battochio, Randy C; Stambulova, Natalia; Schinke, Robert J

    2016-02-01

    Researchers have identified some demands of Canadian National Hockey League (NHL) players, yet there is little direction for players hoping to reach the lucrative league. The objectives of this study were to identify the stages, statuses and demands in Canadian NHL players' careers and propose an empirical career model of Canadian NHL players. In total, 5 rookies, 5 veterans and 13 retirees had their interviews undergo an interpretive thematic analysis. Prospects face the NHL combine, training camp and minor league assignment. While developing into NHL players, rookies deal with NHL call-ups, team competition and formative production while sophomores seemed preoccupied by the opposition. Prime veterans become All-Stars by garnering point production and challenging for the Stanley Cup while seasoned veterans remain relevant through training camps. A discussion about the model's viability is followed by applications for sport psychology researchers and practitioners. PMID:26087366

  20. CHRONIC LEG PAIN IN A DIVISION II FIELD HOCKEY PLAYER: A CASE REPORT

    PubMed Central

    Snowden, Julie; Becker, Jonathan A.; Hazle, Charles

    2014-01-01

    Exertional compartment syndromes in athletes represent a diagnostic and management challenge for clinicians. The clinical presentation of exertional compartment syndrome is similar to other more common musculoskeletal disorders. A lack of special tests or unique diagnostic identifiers for use in decision making by out?patient clinicians complicates early recognition of this disorder and may delay optimal management. The purpose of this case report is to retrospectively explore the clinical presentation and the decision?making during the course of care of a field hockey athlete eventually determined to have exertional compartment syndrome. Suggestions to assist in recognition and guidance in patient management are included as well as the procedures required for differential diagnosis. Procedures utilized during conservative care are also described in detail. Level of Evidence: 5 (Single Case Report) PMID:24567863

  1. Anxiety and burnout in female collegiate ice hockey and soccer athletes.

    PubMed

    Wiggins, Matthew S; Lai, Christopher; Deiters, Jay A

    2005-10-01

    The purpose of this study was to assess whether athletes who perceived their scores on trait anxiety to be debilitative to performance also experienced higher burnout scores. 84 NCAA Division I female ice hockey and soccer athletes, ages 18 to 23 years, volunteered. Participants were given a trait version of the Competitive State Anxiety Inventory-2 with an added direction scale to collect general perceptions of anxiety. They also completed the Burnout Inventory for Athletes. A one-way multivariate analysis of variance for group anxiety yielded an overall significant effect, with the Facilitative group (n = 40) reporting a lower mean burnout score. Mean intensity of cognitive anxiety was significantly higher for the Debilitative group (n = 44), while mean self-confidence intensity was significantly higher for the Facilitative group. PMID:16383089

  2. Physical and performance differences among forwards, defensemen, and goalies in elite women's ice hockey.

    PubMed

    Geithner, Christina A; Lee, Amanda M; Bracko, Michael R

    2006-08-01

    Positional differences have been examined in women's basketball, field hockey, netball, and volleyball, but not in elite women's ice hockey. Our purpose was to describe and compare physical, fitness, and skating performance characteristics of forwards (F), defensemen (D), and goalies (G). Subjects were 112 University of Alberta women players (21.4 +/- 2.9 years of age). A full anthropometric battery was conducted on each player. Heath-Carter anthropometric somatotypes were calculated. Percent body fat (%fat) was estimated from both general and population-specific equations. Subjects performed off-ice fitness tests (vertical jump, 40-yd dash, Leger test for predicting .V(O2)max) and on-ice fitness (Modified 3-Repeat Sprint Skate Test-MRSS, blood lactate after sprint test) and skating performance tests (6.10-m acceleration test, Cornering S-Turn Agility Test). Descriptive statistics and multivariate analyses of variance were run using SPSS (Version 10.0) for the MacIntosh, with a significance level set a priori at p < 0.05. Significant positional differences were found for bicristal breadths (D > G, F > G); relaxed arm circumference (D > F, G > F); supraspinale and biceps skinfolds (G > D, G > F); and endomorphy (G > F). Significant differences among positions were also found for the MRSS (G > D > F) and agility tests (G > D, G > F). D tended to have the most robust build overall. F were leaner than D and G, and their smaller relaxed arm circumference measurements most likely reflect less subcutaneous fat on the upper arm. F had greater anaerobic power than D, followed by G, and they tended to have greater aerobic capacity. F and D were more agile than G. Performance demands appear to be position specific. F need to be the most versatile and fit because of a greater amount and variety of work performed both during practices and games; their required degrees of versatility and fitness are followed by those required of D and G. PMID:16977704

  3. Recreational ice hockey injuries in adult non-checking leagues: a United States perspective.

    PubMed

    Caputo, Pasqualino; Mattson, Douglas J

    2005-03-01

    The purpose of this study was to analyze injuries among adult recreational ice hockey players. This was an observational prospective cohort study with data collected on injuries sustained during one season in the adult recreational ice hockey leagues of Oneida County, NY. The injury incidence rate was found to be 12.2/1000 player-exposures. The most common anatomic region injured was the head/neck/face (35%). Collisions were most often reported as the mechanism of injury (44%). Fracture was the most common diagnosis. Of players wearing face protection (full cage or shield, or partial visor/half shield), none suffered facial injuries, while all facial injuries reported were to players not wearing facial protection. The concussion rate was 1.1/1000 player-exposures. A lack of protective equipment was associated with 38% of injuries and 24% of injuries involved penalties. A history of prior injuries was found in 89% of injured players with 28% re-injuring the same body part. This study's findings suggested various strategies to address player injuries such as mandatory full facial protection and shoulder pads, strict enforcement of game rules, and game rule modifications (no body checking). Further research is needed on the role of preventive rehabilitation in players with previous injury history. Key PointsThe injury incidence rate was found to be 12.2/1000 player-exposures, similar to previous Canadian literature.The concussion rate was 1.1/1000 player-exposures.38% of injuries involved a lack of protective equipment and 24% of injuries involved penalties.Full facial protection and shoulder pads should be compulsory.Strict enforcement of game rules is necessary.History of prior injuries was found in 89% of injured players. PMID:24431962

  4. Recreational Ice Hockey Injuries in Adult Non-Checking Leagues: A United States Perspective

    PubMed Central

    Caputo, Pasqualino; Mattson, Douglas J.

    2005-01-01

    The purpose of this study was to analyze injuries among adult recreational ice hockey players. This was an observational prospective cohort study with data collected on injuries sustained during one season in the adult recreational ice hockey leagues of Oneida County, NY. The injury incidence rate was found to be 12.2/1000 player-exposures. The most common anatomic region injured was the head/neck/face (35%). Collisions were most often reported as the mechanism of injury (44%). Fracture was the most common diagnosis. Of players wearing face protection (full cage or shield, or partial visor/half shield), none suffered facial injuries, while all facial injuries reported were to players not wearing facial protection. The concussion rate was 1.1/1000 player-exposures. A lack of protective equipment was associated with 38% of injuries and 24% of injuries involved penalties. A history of prior injuries was found in 89% of injured players with 28% re-injuring the same body part. This studys findings suggested various strategies to address player injuries such as mandatory full facial protection and shoulder pads, strict enforcement of game rules, and game rule modifications (no body checking). Further research is needed on the role of preventive rehabilitation in players with previous injury history. Key Points The injury incidence rate was found to be 12.2/1000 player-exposures, similar to previous Canadian literature. The concussion rate was 1.1/1000 player-exposures. 38% of injuries involved a lack of protective equipment and 24% of injuries involved penalties. Full facial protection and shoulder pads should be compulsory. Strict enforcement of game rules is necessary. History of prior injuries was found in 89% of injured players. PMID:24431962

  5. Do Canadian collegiate hockey players accurately perceive body composition changes after unmonitored training and diet?

    PubMed

    Prokop, Neal W; Duncan, Lindsay R; Andersen, Ross E

    2015-10-01

    Collegiate athletes often use nutritional programs and supplements to elicit body composition changes in muscle or fat. It is unknown if athletes can accurately perceive their fluctuations in body composition, yet their understanding may help them make more accurate interpretations regarding the success of potential nutrition or exercise regimens. The purpose of this study was to investigate if collegiate hockey players could accurately perceive a change in body composition during a 3-month period within their regular season, in which no predetermined nutritional or exercise program was provided. Twenty-four male Canadian collegiate hockey players completed preseason and midseason body composition assessments using dual-energy X-ray absorptiometry. Immediately before the midseason scan, players attempted to accurately match their perceived fluctuation in composition, with predetermined categorical ranges of relative body composition and strength. Two-thirds of players and one-half of players accurately perceived changes in arm-lean and arm-fat tissue, respectively. Approximately two-thirds of players did not accurately perceive gains or losses of lean or fat tissue within their leg and overall body. Although some athletes partially detected changes in the lean and fat tissue of particular regions, the vast majority of players cannot detect the type, or amount of tissue gained and lost across the overall body. Body composition assessments, rather than an athlete's perceptions, should be used to help interpret the success of a sport nutrition or exercise program. Athletes should be aware that physiologic adaptations might take place unnoticed, which could affect the acceptance and adherence of nutrition or exercise interventions. PMID:26394260

  6. Repair of flexor carpi radialis tendon laceration at the wrist in a professional ice hockey player.

    PubMed

    Hepper, Clifford T; Boyer, Martin

    2011-06-01

    The flexor carpi radialis is a wrist flexor and radial deviator with half the relative strength of flexor carpi ulnaris. In the majority of patients, the flexor carpi radialis tendon is expendable and is routinely used for various reconstructive procedures about the hand and wrist. Isolated flexor carpi radialis lacerations at the wrist are rare. Flexor carpi radialis tendon ruptures, which have been reported in association with distal radius fractures, longstanding osteoarthritis, and percutaneous treatment of scaphoid fractures, are usually treated non-operatively. We report a case of a traumatic laceration of the flexor carpi radialis tendon at the wrist in a professional ice hockey player. Surgical repair and rehabilitation using established principles for intrasynovial flexor tendon repair allowed return to sport at the professional level in 2 months.Tension-free core suture repair was performed with a modified-Kessler, 4-strand repair using a double-stranded 4-0 Supramid suture. A running epitendinous suture was then placed around the circumference of the tendon with 6-0 Prolene. Immobilization of the wrist in 20 of flexion was maintained for 2 weeks. Full active and passive digital motion was allowed immediately postoperatively and continued throughout the rehabilitation. Therapy was initiated at 2 weeks postoperatively with full passive wrist flexion and passive wrist extension to a dorsal block of 20. At 4 weeks postoperatively, a dorsal splint was fabricated to keep the wrist in neutral. At this time, active extension to a dorsal block of zero and full passive flexion was allowed. Active wrist flexion without resistance was begun at 6 weeks, and full strengthening was allowed at 8 weeks postoperatively. The patient returned to sport at the professional level shortly thereafter. At latest follow-up, the patient has been able to fully participate in professional ice hockey without pain or functional limitation. PMID:21667915

  7. Tsunami Hockey

    NASA Astrophysics Data System (ADS)

    Weinstein, S.; Becker, N. C.; Wang, D.; Fryer, G. J.

    2013-12-01

    An important issue that vexes tsunami warning centers (TWCs) is when to cancel a tsunami warning once it is in effect. Emergency managers often face a variety of pressures to allow the public to resume their normal activities, but allowing coastal populations to return too quickly can put them at risk. A TWC must, therefore, exercise caution when cancelling a warning. Kim and Whitmore (2013) show that in many cases a TWC can use the decay of tsunami oscillations in a harbor to forecast when its amplitudes will fall to safe levels. This technique should prove reasonably robust for local tsunamis (those that are potentially dangerous within only 100 km of their source region) and for regional tsunamis (whose danger is limited to within 1000km of the source region) as well. For ocean-crossing destructive tsunamis such as the 11 March 2011 Tohoku tsunami, however, this technique may be inadequate. When a tsunami propagates across the ocean basin, it will encounter topographic obstacles such as seamount chains or coastlines, resulting in coherent reflections that can propagate great distances. When these reflections reach previously-impacted coastlines, they can recharge decaying tsunami oscillations and make them hazardous again. Warning center scientists should forecast sea-level records for 24 hours beyond the initial tsunami arrival in order to observe any potential reflections that may pose a hazard. Animations are a convenient way to visualize reflections and gain a broad geographic overview of their impacts. The Pacific Tsunami Warning Center has developed tools based on tsunami simulations using the RIFT tsunami forecast model. RIFT is a linear, parallelized numerical tsunami propagation model that runs very efficiently on a multi-CPU system (Wang et al, 2012). It can simulate 30-hours of tsunami wave propagation in the Pacific Ocean at 4 arc minute resolution in approximately 6 minutes of real time on a 12-CPU system. Constructing a 30-hour animation using 1 minute simulated time steps takes approximately 50 minutes on the same system. These animations are generated quickly enough to provide decision support for emergency managers whose coastlines may be impacted by the tsunami several hours later. Tsunami reflections can also aid in determining the source region for those tsunamis generated by non-seismic mechanisms without a clear source such as meteotsunamis, tsunamis generated by meteorological phenomena. A derecho that crossed the New Jersey coast and entered the Atlantic Ocean at approximately 1500 UTC June 13, 2013 generated a meteotsunami that struck the northeast coast of the US causing several injuries. A DART sensor off Montauk, NY, recorded tsunami waves approximately 200 minutes apart. We show how the arrival times of the tsunamis recorded by this DART can help to constrain the source region of the meteotsunami. We also examine other reflections produced by the Haida Gwaii 2012, Tohoku 2011, and other tsunamis.

  8. A prospective study of concussions among National Hockey League players during regular season games: the NHL-NHLPA Concussion Program

    PubMed Central

    Benson, Brian W.; Meeuwisse, Willem H.; Rizos, John; Kang, Jian; Burke, Charles J.

    2011-01-01

    Background In 1997, the National Hockey League (NHL) and NHL Players Association (NHLPA) launched a concussion program to improve the understanding of this injury. We explored initial postconcussion signs, symptoms, physical examination findings and time loss (i.e., time between the injury and medical clearance by the physician to return to competitive play), experienced by male professional ice-hockey players, and assessed the utility of initial postconcussion clinical manifestations in predicting time loss among hockey players. Methods We conducted a prospective case series of concussions over seven NHL regular seasons (19972004) using an inclusive cohort of players. The primary outcome was concussion and the secondary outcome was time loss. NHL team physicians documented post-concussion clinical manifestations and recorded the date when a player was medically cleared to return to play. Results Team physicians reported 559 concussions during regular season games. The estimated incidence was 1.8 concussions per 1000 player-hours. The most common postconcussion symptom was headache (71%). On average, time loss (in days) increased 2.25 times (95% confidence interval [CI] 1.413.62) for every subsequent (i.e., recurrent) concussion sustained during the study period. Controlling for age and position, significant predictors of time loss were postconcussion headache (p < 0.001), low energy or fatigue (p = 0.01), amnesia (p = 0.02) and abnormal neurologic examination (p = 0.01). Using a previously suggested time loss cut-point of 10 days, headache (odds ratio [OR] 2.17, 95% CI 1.333.54) and low energy or fatigue (OR 1.72, 95% CI 1.042.85) were significant predictors of time loss of more than 10 days. Interpretation Postconcussion headache, low energy or fatigue, amnesia and abnormal neurologic examination were significant predictors of time loss among professional hockey players. PMID:21502355

  9. Youth sports & public health: framing risks of mild traumatic brain injury in american football and ice hockey.

    PubMed

    Bachynski, Kathleen E; Goldberg, Daniel S

    2014-01-01

    The framing of the risks of experiencing mild traumatic brain injury in American football and ice hockey has an enormous impact in defining the scope of the problem and the remedies that are prioritized. According to the prevailing risk frame, an acceptable level of safety can be maintained in these contact sports through the application of technology, rule changes, and laws. An alternative frame acknowledging that these sports carry significant risks would produce very different ethical, political, and social debates. PMID:25264090

  10. A Cool Sport Full of Physics

    ERIC Educational Resources Information Center

    Hache, Alain

    2008-01-01

    Of all sports, ice hockey is possibly the one with the widest array of physics elements in it. The game provides many examples that can bring physics to life in the classroom. Ice hockey (or just "hockey" as many Canadians would say) sees athletes sliding on ice at high speeds and in various ways, shooting and slapping pucks, and colliding against

  11. A Cool Sport Full of Physics

    ERIC Educational Resources Information Center

    Hache, Alain

    2008-01-01

    Of all sports, ice hockey is possibly the one with the widest array of physics elements in it. The game provides many examples that can bring physics to life in the classroom. Ice hockey (or just "hockey" as many Canadians would say) sees athletes sliding on ice at high speeds and in various ways, shooting and slapping pucks, and colliding against…

  12. Performance and Return to Sport After Anterior Cruciate Ligament Reconstruction in National Hockey League Players

    PubMed Central

    Erickson, Brandon J.; Harris, Joshua D.; Cole, Brian J.; Frank, Rachel M.; Fillingham, Yale A.; Ellman, Michael B.; Verma, Nikhil N.; Bach, Bernard R.

    2014-01-01

    Background: Anterior cruciate ligament (ACL) rupture is a significant injury in male National Hockey League (NHL) players. Purpose: To determine (1) the return to sport (RTS) rate in the NHL following ACL reconstruction, (2) performance on RTS, and (3) the difference in RTS and performance between players who underwent ACL reconstruction and controls. Study Design: Cohort study; Level of evidence, 3. Methods: NHL players undergoing ACL reconstruction were evaluated. All demographic data were analyzed. Matched controls were selected from the NHL during the same years as those undergoing ACL reconstruction. The index year (relative to the number of years of experience in the NHL) in controls was the same as the year that cases underwent ACL reconstruction. RTS and performance in the NHL were analyzed and compared between cases and controls. Student t tests were performed for analysis of within- and between-group variables. Bonferroni correction was used in the setting of multiple comparisons. Results: A total of 36 players (37 knees) meeting the inclusion criteria underwent ACL reconstruction while in the NHL. Thirty-five players were able to RTS in the NHL (97%), and 1 player returned to the international Kontinental Hockey League. Of the players who RTS in the NHL, 100% were able to RTS the season after ACL reconstruction (mean, 7.8 2.4 months). Length of career in the NHL after ACL reconstruction was 4.47 3.3 years. The revision rate was 2.5%. There were significantly more cases playing in the NHL at 3 (P = .027) and 4 (P = .029) years following surgery compared with controls (index year). After ACL reconstruction, player performance was not significantly different from preinjury performance. Following ACL reconstruction (or index year in controls), cases played significantly more minutes, took more shots, had better shooting percentages, and scored more goals and points than did controls (P < .01 for all). Control players did not significantly outperform cases after ACL reconstruction in any performance measure. Conclusion: There is a high RTS rate in the NHL following ACL reconstruction. All players who RTS did so the season following surgery. Performance following ACL reconstruction was not significantly different from preinjury. Cases performed better than did controls in several performance measures. Controls did not outperform cases in any measured performance variable. PMID:26535359

  13. Can injury in major junior hockey players be predicted by a pre-season functional movement screen a prospective cohort study

    PubMed Central

    Dossa, Khaled; Cashman, Glenn; Howitt, Scott; West, Bill; Murray, Nick

    2014-01-01

    Background: The Functional Movement Screen (FMS) is a tool that is commonly used to predict the occurrence of injury. Previous studies have shown that a score of 14 or less (with a maximum possible score of 21) successfully predicted future injury occurrence in athletes. No studies have looked at the use of the FMS to predict injuries in hockey players. Objective: To see if injury in major junior hockey players can be predicted by a preseason FMS. Methods: A convenience sample of 20 hockey players was scored on the FMS prior to the start of the hockey season. Injuries and number of man-games lost for each injury were documented over the course of the season. Results: The mean FMS score was 14.7+/?2.58. Those with an FMS score of ?14 were not more likely to sustain an injury as determined by the Fishers exact test (one-tailed, P = 0.32). Conclusion: This study did not support the notion that lower FMS scores predict injury in major junior hockey players. PMID:25550667

  14. Comparison of impact characteristics of four different ice hockey arena dasher boards.

    PubMed

    Poutiainen, Piritta; Peltonen, Jussi; Isolehto, Juha; Avela, Janne

    2014-01-01

    During recent years the incidence of ice hockey related concussions has increased. Therefore, the main aim of this study was to determine how dasher board materials and structures affect impact characteristics and thereby concussion risk. The measurements were divided into two parts; 1. physiological characteristics of body checks were determined in real game measurements, and 2. simulation of body checks in the laboratory. Peak forces and stopping distances were determined from the high-speed camera data, and stiffness values were subsequently calculated. Dasher board materials and structures had a clear effect on impact characteristics. Flexible protective shielding material resulted in 17% and 16% lower peak forces, 110% and 136% greater stopping distances and 62% and 56% lower stiffness values in the straight and the corner parts of the dasher board, respectively, compared to the reference dasher board. However, the dasher board with flexible protective shielding material including metal shielding support posts between each shielding panel yielded inconsistent results. The shielding support posts were much stiffer compared to the protective shielding. The single-framed dasher board was found to be 29% and 11% more flexible than its dual-framed counterpart, and heavier protective shielding resulted in 33% and 19% higher element stiffness in the straight and the corner parts of the dasher board, respectively. In light of the results and the epidemiology of concussions, it seems that the most safe dasher board would be single-framed with light and flexible protective shielding material, and would not include shielding support posts. PMID:24533490

  15. Defining the effective impact mass of elbow and shoulder strikes in ice hockey.

    PubMed

    Rousseau, Philippe; Hoshizaki, Thomas B

    2015-03-01

    Reconstruction of real-life events can be used to investigate the relationship between the mechanical parameters of the impact and concussion risk. Striking mass has typically been approximated as being the mass of the body part coming into contact with the head without accounting for the force applied by the striking athlete. Thus, the purpose of this study was to measure the effective impact mass of three common striking techniques in ice hockey. Fifteen participants were instructed to strike a suspended 50th percentile Hybrid III headform at least three times with their elbow or shoulder. Effective impact mass was calculated by measuring the change in velocity of the player and the headform. Mean effective impact mass for the extended elbow, tucked-in elbow, and shoulder check conditions were 4.8, 3.0, and 12.9kg, respectively. Peak linear accelerations were lower than the values associated with concussion in American football which could be a reflection of the methodology used in this study as well as inherent differences between both sports. PMID:25895554

  16. A Comparison of Somatic Variables of Elite Ice Hockey Players from the Czech ELH and Russian KHL

    PubMed Central

    Kutáč, Petr; Sigmund, Martin

    2015-01-01

    The goals of this study were to evaluate the basic morphological variables of contemporary elite ice hockey players, compare the parameters of players in the top Russian ice hockey league (KHL) with those of the top Czech ice hockey league (ELH), and to evaluate the parameters of players according to their position in the game. The research participants included 30 KHL players (mean age: 27.1 ± 5.1 years) and 25 ELH players (mean age: 26.4 ± 5.8 years). We determined body height, body mass, and body composition (body fat, fat-free mass, segmental fat analysis). All measurements were performed at the end of preseason training. The KHL players had the following anthropometric characteristics: body height 182.97 ± 5.61 cm (forward) and 185.72 ± 3.57 cm (defenseman), body mass 89.70 ± 5.28 kg (forward) and 92.52 ± 4.01 kg (defenseman), body fat 10.76 ± 0.63 kg (forward) and 11.10 ± 0.48 kg (defenseman), fat-free mass 78.94 ± 4.65 kg (forward) and 81.42 ± 3.52 kg (defenseman). The values for ELH players were as follows: body height 182.06 ± 5.93 cm (forward) and 185.88 ± 7.13 cm (defenseman), body mass 88.47 ± 7.06 kg (forward) and 89.36 ± 10.91 kg (defenseman), body fat 12.57 ± 2.89 kg (forward) and 11.91 ± 3.10 kg (defenseman), fat-free mass 75.93 ± 6.54 kg (forward) and 77.46 ± 7.89 kg (defenseman). The results indicate that it is beneficial to ice hockey players to have increased body mass and lower body fat, which leads to higher muscle mass, thus enabling a player to perform at the highest level and meet the specific challenges of the game. PMID:25949747

  17. Ability of Preseason Body Composition and Physical Fitness to Predict the Risk of Injury in Male Collegiate Hockey Players

    PubMed Central

    Grant, John A.; Bedi, Asheesh; Kurz, Jennifer; Bancroft, Richard; Gagnier, Joel J.; Miller, Bruce S.

    2015-01-01

    Background: Injuries in collegiate ice hockey can result in significant time lost from play. The identification of modifiable risk factors relating to a players physical fitness allows the development of focused training and injury prevention programs targeted at reducing these risks. Purpose: To determine the ability of preseason fitness outcomes to predict in-season on-ice injury in male collegiate ice hockey players. Study Design: Prognostic cohort study. Level of Evidence: Level 3. Methods: Athlete demographics, percentage body fat, aerobic capacity (300-m shuttle run; 1-, 1.5-, 5-mile run), and strength assessment (sit-ups, push-ups, grip strength, bench press, Olympic cleans, squats) data were collected at the beginning of 8 successive seasons for 1 male collegiate ice hockey team. Hockey-related injury data and player-level practice/game athlete exposure (AE) data were also prospectively collected. Seventy-nine players participated (203 player-years). Injury was defined as any event that resulted in the athlete being unable to participate in 1 or more practices or games following the event. Multivariable logistic regression was performed to determine the ability of the independent variables to predict the occurrence of on-ice injury. Results: There were 132 injuries (mean, 16.5 per year) in 55 athletes. The overall injury rate was 4.4 injuries per 1000 AEs. Forwards suffered 68% of the injuries. Seventy percent of injuries occurred during games with equal distribution between the 3 periods. The mean number of days lost due to injury was 7.8 13.8 (range, 1-127 days). The most common mechanism of injury was contact with another player (54%). The odds of injury in a forward was 1.9 times (95% CI, 1.1-3.4) that of a defenseman and 3 times (95% CI, 1.2-7.7) that of a goalie. The odds of injury if the players body mass index (BMI) was ?25 kg/m2 was 2.1 times (95% CI, 1.1-3.8) that of a player with a BMI <25 kg/m2. The odds ratios for bench press, maximum sit-ups, and Olympic cleans were statistically significant but close to 1.0, and therefore the clinical relevance is unknown. Conclusion: Forwards have higher odds of injury relative to other player positions. BMI was predictive of on-ice injury. Aerobic fitness and maximum strength outcomes were not strongly predictive of on-ice injury. PMID:25553212

  18. Pre-competition hormonal and psychological levels of elite hockey players: relationship to the "home advantage".

    PubMed

    Carr, Justin; Muir, Cameron; Belanger, Joey; Putnam, Susan K

    2006-10-30

    The home advantage is a robust phenomenon that occurs in the world of amateur and professional sport. Athletic teams have been shown to win significantly more games in their home venue as compared to their opponents' venue. Studies have suggested that the home advantage may be related to familiarity with the facility, increased crowd density and even pre-competition hormonal levels. The present study investigated pre-competition physiological and psychological states of elite hockey players in the home and away venues. Physiological measures included salivary cortisol and testosterone, which were assessed using enzyme immunoassays. In addition, pre-competition psychological states were assessed using the Competitive State Anxiety Inventory-2. Physiological measures indicated that the players had significantly higher pre-game testosterone when playing in their home venue as compared to their opponents' venue (t(13)=2.29, p=0.04); however, this difference was not due to a pre-game rise in testosterone while competing at home. Furthermore, players showed a trend toward higher pre-game cortisol when playing in their home venue (t(13)=1.96, p=0.07). Psychological measures indicated that players were more self-confident when playing in their home venue (t(13)=2.8, p=0.008) and also had higher somatic (t(13)=2.3, p=0.02) and cognitive anxiety (t(13)=1.87, p=0.04) when playing in their opponents' venue. The present study supports the notion that there are differences in pre-competition hormonal and psychological states that may play a key role in the "home advantage". PMID:16934844

  19. Head impact exposure in male and female collegiate ice hockey players.

    PubMed

    Wilcox, Bethany J; Beckwith, Jonathan G; Greenwald, Richard M; Chu, Jeffrey J; McAllister, Thomas W; Flashman, Laura A; Maerlender, Arthur C; Duhaime, Ann-Christine; Crisco, Joseph J

    2014-01-01

    The purpose of this study was to quantify head impact exposure (frequency, location and magnitude of head impacts) for individual male and female collegiate ice hockey players and to investigate differences in exposure by sex, player position, session type, and team. Ninety-nine (41 male, 58 female) players were enrolled and 37,411 impacts were recorded over three seasons. Frequency of impacts varied significantly by sex (males: 287 per season, females: 170, p<0.001) and helmet impact location (p<0.001), but not by player position (p=0.088). Head impact frequency also varied by session type; both male and female players sustained more impacts in games than in practices (p<0.001), however the magnitude of impacts did not differ between session types. There was no difference in 95th percentile peak linear acceleration between sexes (males: 41.6 g, females: 40.8 g), but 95th percentile peak rotational acceleration and HITsp (a composite severity measure) were greater for males than females (4424, 3409 rad/s(2), and 25.6, 22.3, respectively). Impacts to the back of the helmet resulted in the greatest 95th percentile peak linear accelerations for males (45.2 g) and females (50.4 g), while impacts to the side and back of the head were associated with the greatest 95th percentile peak rotational accelerations (males: 4719, 4256 rad/sec(2), females: 3567, 3784 rad/sec(2) respectively). It has been proposed that reducing an individual's head impact exposure is a practical approach for reducing the risk of brain injuries. Strategies to decrease an individual athlete's exposure need to be sport and gender specific, with considerations for team and session type. PMID:24210478

  20. Muscle Oxygen Changes following Sprint Interval Cycling Training in Elite Field Hockey Players

    PubMed Central

    Jones, Ben; Hamilton, David K.; Cooper, Chris E.

    2015-01-01

    This study examined the effects of Sprint Interval Cycling (SIT) on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (IFT). Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP) and a control group (CON). The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS) measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2), tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb), total tissue haemoglobin (tHb) and tissue oxygenation (TSI %) were taken. In the EXP group (5.34±0.14 to 5.50±0.14m.s-1) but not the CON group (pre = 5.37±0.27 to 5.39±0.30m.s-1) significant changes were seen in the 30-15IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (−7.59±0.91 to −12.16±2.70%); ΔHHb+HMb (35.68±6.67 to 69.44±26.48μM.cm); and ΔHbO2+ MbO2 (−74.29±13.82 to −109.36±22.61μM.cm). No significant differences were seen in ΔtHb (−45.81±15.23 to −42.93±16.24). NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes. PMID:25807517

  1. Physiological responses to repeated apneas in underwater hockey players and controls.

    PubMed

    Lematre, F; Polin, D; Joulia, F; Boutry, A; Le Pessot, D; Chollet, D; Tourny-Chollet, C

    2007-01-01

    The aim of this study was to investigate the effects of short repeated apneas on breathing pattern and circulatory response in trained (underwater hockey players: UHP) and untrained (controls: CTL) subjects. The subjects performed five apneas (A1-A5) while cycling with the face immersed in thermoneutral water. Respiratory parameters were recorded 1 minute before and after each apnea and venous blood samples were collected before each apnea and at 0, 2, 5 and 10 minutes after the last apnea. Arterial saturation (SaO2) and heart rate were continuously recorded during the experiment. Before the repeated apneas, UHP had lower ventilation, higher P(ET)CO2 (p < 0.05) and lower P(ET)O2 than CTL (p < 0.001). After the apneas, the P(ET)O2 values were always lower in UHP (p < 0.001) than CTL but with no difference for averaged P(ET)CO2 (p = 0.32). The apnea response, i.e., bradycardia and increased mean arterial blood pressure, was observed and it remained unchanged throughout the series in the two groups. The SaO, decreased in both groups during each apnea but the post-exercise SaO2 values were higher in UHP after A2 to A5 than in CTL (p < 0.01). The post-apnea lactate concentrations were lower in UHP than in CTL. These results indicate that more pronounced bradycardia could lead to less oxygen desaturation during repeated apneas in UHP. The UHP show a specific hypoventilatory pattern after repeated apneas, as well as a more pronounced cardiovascular response than CTL. They indeed showed no detraining of the diving response. PMID:18251437

  2. The effects of heavy upper-body strength training on ice sledge hockey sprint abilities in world class players.

    PubMed

    Sandbakk, yvind; Hansen, Mads; Ettema, Gertjan; Rnnestad, Bent

    2014-12-01

    The current study investigated the effects of 6 weeks of heavy upper-body strength training on maximal strength and sprint abilities in eight world class ice sledge hockey players. Before and after the strength training intervention, all subjects performed a 30-m maximal sprint on ice (where time for each 10 m section was measured) and 1 repetition maximal (1RM) strength test in the bench pull (BP), pull-down (PD), pull over (PO) and front pull (FP) exercises. Three weekly sessions with 36-8RM for these strength exercises were added during the intervention period. From pre- to post-test, 1RM in the strength exercises improved by 4-8%, whereas 30-m sprint time, all 10-m section times and the calculated power output in the 10-m acceleration phase all improved by 2-3% (all P<.05). The pre- to post-test changes in 30-m sprint time and the initial 10-m time correlated significantly with the changes in 1RM for BP (r=0.59 and 0.55) and PD (r=0.60 and 0.68) (all P<.05). In conclusion, the results of this study strongly suggest that heavy upper-body strength training improves upper-body strength and ice sledge hockey sprint abilities, and that the magnitude of improvements in strength correlates with the improvements in sprint abilities. PMID:25457423

  3. Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

    ERIC Educational Resources Information Center

    Vescovi, Jason D.

    2016-01-01

    Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

  4. Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

    ERIC Educational Resources Information Center

    Vescovi, Jason D.

    2016-01-01

    Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,

  5. The Epidemiology of Hip/Groin Injuries in National Collegiate Athletic Association Men’s and Women’s Ice Hockey

    PubMed Central

    Dalton, Sara L.; Zupon, Alyssa B.; Gardner, Elizabeth C.; Djoko, Aristarque; Dompier, Thomas P.; Kerr, Zachary Y.

    2016-01-01

    Background: There is limited research regarding the epidemiology of hip/groin injuries in ice hockey, the majority of which is restricted to time-loss injuries only. Purpose: To describe the epidemiology of hip/groin injuries in collegiate men’s and women’s ice hockey from 2009-2010 through 2014-2015. Study Design: Descriptive epidemiology study. Methods: Hip/groin injury data from the National Collegiate Athletic Association Injury Surveillance Program (NCAA-ISP) during the 2009-2010 through 2014-2015 seasons were analyzed. Injury rates, rate ratios (RRs), and injury proportion ratios (IPRs) were reported with 95% confidence intervals (CIs). Results: During the 2009-2010 through 2014-2015 seasons, 421 and 114 hip/groin injuries were reported in men’s and women’s ice hockey, respectively, leading to injury rates of 1.03 and 0.78 per 1000 athlete-exposures (AEs), respectively. The hip/groin injury rate was greater in men than in women (RR, 1.32; 95% CI, 1.08-1.63). In addition, 55.6% and 71.1% of hip/groin injuries in men’s and women’s ice hockey, respectively, were non–time loss (NTL) injuries (ie, resulted in participation restriction time <24 hours); 7.6% and 0.9%, respectively, were severe (ie, resulted in participation restriction time >3 weeks). The proportion of hip/groin injuries that were NTL injuries was greater in women than in men (IPR, 1.28; 95% CI, 1.11-1.48). Conversely, the proportion of hip/groin injuries that were severe was greater in men than in women (IPR, 8.67; 95% CI, 1.20-62.73). The most common hip/groin injury diagnosis was strain (men, 67.2%; women, 76.3%). Also, 12 (2.9%) and 3 (2.6%) cases of hip impingement were noted in men’s and women’s ice hockey, respectively. Conclusion: Hip/groin injury rates were greater in men’s than in women’s ice hockey. Time loss varied between sexes, with men sustaining more injuries with time loss over 3 weeks. Despite increasing concerns of femoroacetabular impingement in ice hockey players, few cases of hip impingement were reported in this dataset. PMID:26998502

  6. Iron Metabolism in Field Hockey Players During an Annual Training Cycle

    PubMed Central

    Podgórski, Tomasz; Kryściak, Jakub; Konarski, Jan; Domaszewska, Katarzyna; Durkalec-Michalski, Krzysztof; Strzelczyk, Ryszard; Pawlak, Maciej

    2015-01-01

    Post-physical training changes in iron metabolism in the human body often occur. To fully describe these processes, fifteen male Polish National Team field hockey players (age 27.7 ± 5.2 years, body mass 72.8 ± 7.6 kg and body height 177.1 ± 5.7 cm) were examined in three phases of an annual training cycle: preparatory (T1), competitive (T2) and transition (T3). To assess aerobic fitness, maximal oxygen uptake (VO2max) was evaluated. Based on the iron concentration, the changes in total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC) and other selected haematological indicators (haemoglobin, erythrocytes, mean corpuscular haemoglobin - MCH) in iron metabolism were estimated. The average values of maximum oxygen uptake increased from 54.97 ± 3.62 ml·kg−1·min−1 in T1 to 59.93 ± 3.55 ml·kg−1·min−1 in T2 (p<0.05) and then decreased to 56.21 ± 4.56 ml·kg−1·min−1 in T3 (p<0.05). No statistically significant changes in the erythrocyte count were noted. The MCH and haemoglobin concentration decreased between T1 and T2. The maximal exercise test caused a significant (p<0.05) increase in the plasma iron concentration during the competition and transition phases. Progressive but non-significant increases in resting iron concentration, TIBC and UIBC in the analysed annual training cycle were noted. To show global changes in iron metabolism in the human body, it is necessary to determine additional variables, i.e. UIBC, TIBC, haemoglobin, MCH or the erythrocyte count. The direction of changes in iron metabolism depends on both the duration and intensity of the physical activity and the fitness level of the subjects. Dietary intake of iron increases the level of this trace element and prevents anaemia associated with training overloads. PMID:26557195

  7. Quantification of the Demands During an Ice-Hockey Game Based on Intensity Zones Determined From the Incremental Test Outcomes.

    PubMed

    Stanula, Arkadiusz J; Gabry?, Tomasz T; Roczniok, Robert K; Szmatlan-Gabry?, Urszula B; Ozimek, Mariusz J; Mostowik, Aleksandra J

    2016-01-01

    Stanula, A, Gabry?, T, Roczniok, R, Szmatlan-Gabry?, U, Ozimek, M, and Mostowik, A. Quantification of the demands during an ice-hockey game based on intensity zones determined from the incremental test outcomes. J Strength Cond Res 30(1): 176-183, 2016-The purpose of this study was to determine ice-hockey players' playing intensity based on their heart rates (HRs) recorded during a game and on the outcomes of an incremental maximum oxygen uptake test. Sixteen ice-hockey players, members of the Polish national team junior (U20), performed an incremental test to assess their maximal oxygen uptake (V[Combining Dot Above]O2max) in the 2 week's period preceding 4 games they played at the World Championships. Players' HRs at the first and second ventilatory thresholds obtained during the test were used to determine intensity zones (low, moderate, and high) that were subsequently used to classify HR values recorded during each of the games. For individual intensity zones, the following HRs expressed as mean values and as percentages of the maximal heart rate (HRmax) were obtained: forwards, 143-151 bmin (HRmax, 75.2-79.5%), 152-176 bmin (HRmax, 80.0-92.4%), 177-190 bmin (HRmax, 92.9-100.0%); defensemen, 127-139 bmin (HRmax, 69.4-75.8%), 140-163 bmin (HRmax, 76.4-89.0%), 164-184 bmin (HRmax, 89.5-100.0%). The amounts of time the forwards and defensemen spent in the 3 intensity zones expressed as percentages of the total time of the game were the following: 58.75% vs. 44.29% (low), 21.95% vs. 25.84% (moderate), and 19.30% vs. 29.87% (high). The forwards spent average more time in the low-intensity zone than did the defensemen, with the difference being statistically significant in periods 1 and 2 (61.44% vs. 44.21% at p ? 0.001 and 59.14% vs. 47.23% at p ? 0.01, respectively). The results of the study indicate that a method using aerobic and anaerobic metabolism parameters to determine intensity zones can significantly improve the reliability of evaluation of the physiological demands of the game and can be a useful tool for coaches in managing the training process. PMID:26154153

  8. Estimated fluid and sodium balance and drink preferences in elite male junior players during an ice hockey game.

    PubMed

    Logan-Sprenger, Heather M; Palmer, Matthew S; Spriet, Lawrence L

    2011-02-01

    Research in many sports suggests that losing ~2% of body mass (BM) through sweating impairs athletic performance, although this has not been tested in ice hockey players. This study investigated pregame hydration, and on-ice sweat loss, fluid intake, and sodium (Na+) balance of elite male junior players during an ice hockey game. Twenty-four players (2 goalies, 7 defensemen, 15 forwards) volunteered to participate in the study (age, 18.3 0.3years; weight, 86.51.6kg; height, 184.1 1.3cm). Players were weighed pre- and postgame, fluid and sodium intake were monitored throughout the game, and fluid and Na+ balance were determined within the time between BM measurements. Sweat Na+ loss was calculated based on sweat loss and sweat [Na+] determined from sweat-patch analysis on the same players during an intense practice. Players arrived at the rink in a euhydrated state and drank 0.6 0.1 L of fluid before the game. Mean playing time for the forwards was 18:85 1:15min:s and playing time for the defense was 24:00 2:46min:s. Sweat loss was 3.2 0.2 L and exceeded net fluid intake (2.1 0.1 L). Mean BM loss was 1.3% 0.3%, with 8/24 players losing between 1.8% to 4.3% BM. Players preferred to drink water and a carbohydrate electrolyte solution before the game and during intermissions, while only water was consumed during each period. Practice mean forehead sweat [Na+] was 74mmolL-1. Estimated sweat Na+ losses of 3.1 0.4g (~8g NaCl) coupled with low Na+ intake of 0.8 0.2g (~2g NaCl) resulted in a significant Na+ deficit by the end of the game. This study demonstrated that despite abundant opportunities to hydrate during a hockey game, one-third of the players did not drink enough fluid to prevent sweat losses of 2% BM or higher. Losing 2% BM has been associated with decreases in athletic performance. PMID:21326389

  9. Relationship of off-ice and on-ice performance measures in high school male hockey players.

    PubMed

    Krause, David A; Smith, Aynsley M; Holmes, Laura C; Klebe, Corrine R; Lee, Jennifer B; Lundquist, Kimberly M; Eischen, Joseph J; Hollman, John H

    2012-05-01

    The purpose of this study was to examine the relationship of off-ice performance measures with on-ice turning, crossover, and forward skating performance in high school male hockey players. Thirty-eight players aged 15-18 (mean age SD: 16.4 1.1 years; height: 177.9 6.8 cm; weight: 72.5 8.9 kg) participated in this study. On-ice tests included a forward sprint, short radius turns, and crossover turns. Off-ice tests included a 40-yd sprint, vertical jumps, horizontal jumps, and a dynamic balance test using a Y balance testing device. Five off-ice variables correlated with all on-ice performance measures. These variables included the 40-yd sprint, lateral bound right to left limb, double limb horizontal hop, balance on right in posterolateral direction, and composite balance performance on the right. Hierachical regression demonstrated that off-ice sprint time was most predictive of on-ice skating performance, accounting for 65.4% of the variability in forward skate time, 45.0% of the variability in left short radius time, 21.8% of the variance in right short radius time, 36.2% of the variance in left crossover time, and 30.8% of the variability in right crossover time. When using off-ice tests to evaluate hockey players, the 40-yd sprint is the best predictor of skating performance. Based on our regression equation, for every 1-second difference in the 40-yd sprint time, there will be approximately a 0.6-second difference in the 34.5-m on-ice sprint. The 40-yd sprint predicts forward skating performance and to a lesser degree; it also predicts crossover and tuning performance. PMID:22395275

  10. The ability of parents to accurately report concussion occurrence in their bantam-aged minor hockey league children

    PubMed Central

    Coghlin, Craig J; Myles, Bryan D; Howitt, Scott D.

    2009-01-01

    Objective: The objective of this study was to assess the ability of hockey parents/guardians to recognize concussion symptoms in their 1314 year old (Bantam-aged) children. Outcome Measures: The outcome measures were the ability to recognize different signs and symptoms listed on the Sport Concussion Assessment Tool (SCAT) as well as 8 detractors consisting of signs and symptoms not associated with post concussive syndrome. Additional questions assessing the parents knowledge of concussion management and recognition abilities were also posed. Participants: Parents of Bantam-aged minor hockey league athletes volunteered for the study. Methods: The study investigators distributed questionnaires during the warm up period or following their childrens games to the study participants. Following questionnaire completion, participants were provided with an information package outlining the correct signs and symptoms of concussion. Results: The mean number of correct responses to signs and symptoms of concussion was 21.25/25 for the mothers and 20.41/25 for the fathers. The mean number of detractors identified as not associated with concussion was 5.93/8 for the mothers and 4.85/8 for the fathers, indicating that mothers were more capable of recognizing the signs and symptoms than fathers. An analysis of variance including sporting experience in the model did not strengthen the relationship between parent gender and test outcome. Conclusion: This investigation revealed that there is still a disconnect in regards to key components of recognizing a concussion, such as difficulty with sleep, disorientation symptoms, and emotional irritability. Mothers have displayed an ability to better differentiate between true and false signs and symptoms of concussion as compared to fathers. Continued education and awareness of mild traumatic brain injury in athletes should address the misconceptions amongst parents in regards to the true signs and symptoms of a concussion. PMID:20037689

  11. Skin conditions in figure skaters, ice-hockey players and speed skaters: part I - mechanical dermatoses.

    PubMed

    Tlougan, Brook E; Mancini, Anthony J; Mandell, Jenny A; Cohen, David E; Sanchez, Miguel R

    2011-09-01

    Figure skaters, ice-hockey players and speed skaters experience a range of dermatologic conditions and tissue-related injuries on account of mechanical trauma, infectious pathogens, inflammatory processes and environmental factors related to these competitive pursuits. Sports medicine practitioners, family physicians, dermatologists and coaches should be familiar with these skin conditions to ensure timely and accurate diagnosis and management of affected athletes. This review is Part I of a subsequent companion review and provides a comprehensive review of mechanical dermatoses experienced by ice-skating athletes, including skater's nodules and its variants, pump bumps, piezogenic pedal papules, talon noir, skate/lace bite, friction bullae, corns and calluses, onychocryptosis, skater's toe and skate blade-induced lacerations. These injuries result from friction, shear forces, chronic pressure and collisions with surfaces that occur when athletes endure repetitive jump landings, accelerated starts and stops and other manoeuvres during rigorous training and competition. Ill-fitting skates, improper lacing techniques and insufficient lubrication or protective padding of the foot and ankle often contribute to the development of skin conditions that result from these physical and mechanical stresses. As we will explain, simple measures can frequently prevent the development of these conditions. The treatment of skater's nodules involves reduction in chronic stimulation of the malleoli, and the use of keratolytics and intralesional steroid injections; if malleolar bursitis develops, bursa aspirations may be required. Pump bumps, which result from repetitive friction posteriorly, can be prevented by wearing skates that fit correctly at the heel. Piezogenic pedal papules may be treated conservatively by using heel cups, compressive stockings and by reducing prolonged standing. Talon noir usually resolves without intervention within several weeks. The treatment of skate bite is centred on reducing compression by the skate tongue of the extensor tendons of the anterior ankle, which can be accomplished by use of proper lacing techniques, increasing pliability of the skate tongue and using protective padding, such as Bunga Pads™. Anti-inflammatory medications and cold compresses can also help reduce inflammation. Friction bullae are best managed by careful lancing of painful blisters and application of petrolatum or protective dressings to accelerate healing; preventative measures include the use of well fitting skates, proper lacing techniques and moisture-wicking socks. Corns and calluses are similarly best prevented by the use of well fitted skates and orthotic devices. Symptomatic, debridement reduces the irritant effect of the thick epidermis, and can be accomplished by soaking the area in warm water followed by paring. Application of creams with high concentrations of urea or salicylic acid can also soften callosities. Cases of onychocryptosis benefit from warm soaks, antibiotic ointments and topical steroids to reduce inflammation, but sometimes chemical or surgical matricectomies are required. Preventative measures of both onychocryptosis and skater's toe include cutting toenails straight across to allow for a more equal distribution of forces within the toe box. Finally, the prevention and treatment of lacerations, which constitute a potentially fatal type of mechanical injury, require special protective gear and acute surgical intervention with appropriate suturing. The subsequent companion review of skin conditions in ice skaters will discuss infectious, inflammatory and cold-induced dermatoses, with continued emphasis on clinical presentation, diagnosis, treatment and prevention. PMID:21846161

  12. Multinational outbreak of Salmonella Enteritidis infection during an international youth ice hockey competition in Riga, Latvia, preliminary report, March and April 2015.

    PubMed

    Pesola, A K; Parn, T; Huusko, S; Perevos?ikovs, J; Ollgren, J; Salmenlinna, S; Lienemann, T; Gossner, C; Danielsson, N; Rimhanen-Finne, R

    2015-01-01

    A multinational outbreak of salmonellosis linked to the Riga Cup 2015 junior ice-hockey competition was detected by the Finnish health authorities in mid-April and immediately notified at the European Union level. This prompted an international outbreak investigation supported by the European Centre for Disease Prevention and Control. As of 8 May 2015, seven countries have reported 214 confirmed and suspected cases, among which 122 from Finland. The search for the source of the outbreak is ongoing. PMID:26027481

  13. The role of visual perception measures used in sports vision programmes in predicting actual game performance in Division I collegiate hockey players.

    PubMed

    Poltavski, Dmitri; Biberdorf, David

    2015-01-01

    Abstract In the growing field of sports vision little is still known about unique attributes of visual processing in ice hockey and what role visual processing plays in the overall athlete's performance. In the present study we evaluated whether visual, perceptual and cognitive/motor variables collected using the Nike SPARQ Sensory Training Station have significant relevance to the real game statistics of 38 Division I collegiate male and female hockey players. The results demonstrated that 69% of variance in the goals made by forwards in 2011-2013 could be predicted by their faster reaction time to a visual stimulus, better visual memory, better visual discrimination and a faster ability to shift focus between near and far objects. Approximately 33% of variance in game points was significantly related to better discrimination among competing visual stimuli. In addition, reaction time to a visual stimulus as well as stereoptic quickness significantly accounted for 24% of variance in the mean duration of the player's penalty time. This is one of the first studies to show that some of the visual skills that state-of-the-art generalised sports vision programmes are purported to target may indeed be important for hockey players' actual performance on the ice. PMID:25142869

  14. Multidisciplinary approach to non-surgical management of inguinal disruption in a professional hockey player treated with platelet-rich plasma, manual therapy and exercise: a case report

    PubMed Central

    St-Onge, Eric; MacIntyre, Ian G.; Galea, Anthony M.

    2015-01-01

    Objective: To present the clinical management of inguinal disruption in a professional hockey player and highlight the importance of a multidisciplinary approach to diagnosis and management. Clinical Features: A professional hockey player with recurrent groin pain presented to the clinic after an acute exacerbation of pain while playing hockey. Intervention: The patient received a clinical diagnosis of inguinal disruption. Imaging revealed a tear in the rectus abdominis. Management included two platelet-rich plasma (PRP) injections to the injured tissue, and subsequent manual therapy and exercise. The patient returned to his prior level of performance in 3.5 weeks. Discussion: This case demonstrated the importance of a multidisciplinary team and the need for advanced imaging in athletes with groin pain. Summary: Research quality concerning the non-surgical management of inguinal disruption remains low. This case adds evidence that PRP, with the addition of manual therapy and exercise may serve as a relatively quick and effective non-surgical management strategy. PMID:26816415

  15. Sediment quality thresholds: Estimates from hockey stick regression of liver lesion prevalence in English sole (Pleuronectes vetulus)

    SciTech Connect

    Horness, B.H.; Lomax, D.P.; Johnson, L.L.; Myers, M.S.; Pierce, S.M.; Collier, T.K.

    1998-01-01

    Comprehensive, integrative assessments of coastal sediment quality are best effected by using large, diverse data sets that include measures of biological dysfunction observed in association with chronic exposure to sediment contaminants. Under the auspices of the National Oceanic and Atmospheric Administration`s National Status and Trends Program, the National Benthic Surveillance Project accumulated a database of synoptic sediment contaminant concentrations and indices of biological effects that were measured in indigenous animals collected during field surveys conducted from 1984 to 1994. This compilation of data provided the opportunity to develop a new approach for determining sediment quality criteria to add to the current repertoire of environmental assessment tools. Using a two-segment hockey stick regression, statistically significant chemical thresholds of biological effects were estimated for hepatic lesion prevalences in English sole (Pleuronectes vetulus, formerly Parophrys vetulus) in relation to sediment concentrations of polycyclic aromatic hydrocarbons. These threshold estimates are notably lower than many of those reported for other techniques. Application of this relatively simple dose-response model to subacute, chronic effects that are involved in pepatocarcinogenesis and associated with sediment toxicant content (1) reflects the link between toxicopathic disease progression and conditions observed in benthic fish exposed to contaminants and (2) provides endpoints for assessing sediment quality contaminant concentrations that are not necessarily acutely fatal but may have long-term health implications for populations that are chronically exposed.

  16. NON-SURGICAL TREATMENT OF A PROFESSIONAL HOCKEY PLAYER WITH THE SIGNS AND SYMPTOMS OF SPORTS HERNIA: A CASE REPORT

    PubMed Central

    Woodward, J. Scott; Parker, Andrew; MacDonald, Robert M.

    2012-01-01

    Study Design: Case Report Background: Injury or weakness of lower abdominal attachments and the posterior inguinal wall can be symptoms of a sports hernia and an underlying source of groin pain. Although several authors note conservative treatment as the initial step in the management of this condition, very little has been written on the specific description of non-surgical measures. Most published articles favoring operative care describe poor results related to conservative management; however they fail to report what treatment techniques comprise non-operative management. Case Presentation: The subject of this case report is a professional ice hockey player who sustained an abdominal injury in a game, which was diagnosed as a sports hernia. Following the injury, structured conservative treatment emphasized core control and stability with progressive peripheral demand challenges. Intrinsic core control emphasis continued throughout the treatment progression and during the functional training prior to return to sport. Outcome: The player completed his recovery with return to full competition seven weeks post injury, and continues to compete in the NHL seven years later. Discussion: Surgical intervention has been shown to be effective in the treatment of the sports hernia. However it is the authors' opinion that conservative care emphasizing evaluation of intrinsic core muscular deficits and rehabilitation directed at addressing these deficits is an appropriate option, and should be considered prior to surgical intervention. PMID:22319682

  17. Dosimetry of a single ''hockey stick'' portal for treatment of tumors of the cranio-spinal axis

    SciTech Connect

    Glasgow, G.P.; Marks, J.E.

    1983-09-01

    Conventional treatment of tumors of the cranio-spinal axis portal usually involves multiple-field, moving junction treatments to avoid overlapping fields over the spinal cord. To avoid these problems, we irradiate the cranio-spinal axis using a single ''hockey stick'' portal and the 25-MV x-ray beam from a Varian Clinac-35/sup X/ linear accelerator. Patients are positioned prone on the floor 229 cm from the radiation source and the collimators are rotated 45/sup 0/ so the maximum diagonal dimension of the field 116 cm at 229 cm is coincident with the cranio-spinal axis. The head is alternately rotated to treat the right-hand side one day and the left-hand side the next day. Thermoluminescent dosimetry in an anatomical phantom reveals that, relative to the 100% dose delivered at 4-cm depth on the central axis of the blocked field, the midline posterior fossa dose is about 100%, with a maximum dose of about 105% to the extreme posterior portion of the skull. The midline neck dose is about 95% and the dose to the inferior portion of the spinal cord is about 105%. The doses to other critical organs are also presented.

  18. The prevalence of musculoskeletal pain and use of painkillers among adolescent male ice hockey players in Finland

    PubMed Central

    Selanne, Harri; Ryba, Tatiana V.; Siekkinen, Kirsti; Kyrlinen, Heikki; Kautiainen, Hannu; Hakonen, Harto; Mikkelsson, Marja; Kujala, Urho M.

    2014-01-01

    Participating in competitive sport increases the risk for injuries and musculoskeletal pain among adolescent athletes. There is also evidence that the use of prescription drugs has increased among sport club athletes. The purpose of this study was to evaluate the use of painkillers among young male ice hockey players (IHP) in comparison to schoolboys (controls) and its relation to the prevalence of musculoskeletal pain and problems during activities and sleeping. Information was gathered through a questionnaire, completed by 121 IHP and compared to the responses of 618 age-matched controls. Results showed that monthly existing pain was at 82% for IHP, and 72% for controls, though IHP had statistically more musculoskeletal pain in their lower limbs (56% vs. 44%), lower back (54% vs. 35%), and buttocks (26% vs. 11%). There were no group differences in the neck, upper back, upper limb, or chest areas. The disability index was statistically similar for both groups, as musculoskeletal pain causing difficulties in daily activities and sleeping was reported by a minority of subjects. Despite this similarity, IHP used more painkillers than controls (18% vs. 10%). Further nuanced research is encouraged to compare athletes and non-athletes in relation to painkillers. PMID:25750794

  19. CATECHOLAMINES AND β2-ADRENOCEPTOR GENE EXPRESSION BEFORE AND AFTER MAXIMAL INCREMENTAL CYCLE TEST IN YOUNG ICE HOCKEY PLAYERS: RELATION TO WORK PERFORMED

    PubMed Central

    Janikowska, G.; Bogacz, A.; Bijak, A.; Stanjek-Cichoracka, A.; Mazurek, U.; Gabrys, T.

    2013-01-01

    The aim of this study was to assess the plasma adrenaline and noradrenaline concentrations as well as whole blood β2-adrenoceptor gene (ADRB2) expression in young ice hockey players before and immediately after exercise in relation to performed work. Nineteen Youth National Team ice hockey players were subjected to the maximal incremental cycloergometer exercise. The test was done in the pre-competitive phase of training. Among many parameters the plasma adrenaline and noradrenaline concentrations and ADRB2 gene expression in peripheral blood mononuclear cells (PBMC) were determined before and after exercise. The average performed work was 3261.3 ± 558.3 J · kg−1 and maximal oxygen consumption (VO2max) for all players was 53.85 ± 3.91 mL · kg−1 min−1. The geometric mean of the ADRB2 gene expression was statistically significantly different before and after exercise (P ≤ 0.05), while adrenaline and noradrenaline levels in plasma significantly increased after exercise. In the analysed group of athletes we found that initial level of plasma noradrenaline correlated with the performed work (r = - 0.55, P < 0.014) and normalized ADRB2 expression before the exercise correlated with the work done by them (r = 0.48, P<0.039). However, no statistically significant correlations were found between the plasma adrenaline or noradrenaline concentrations and ADRB2 gene expression in peripheral blood of the players. The performed work in the maximal incremental exercise test of regularly training young ice hockey players depends on the initial levels of noradrenaline in plasma and ADRB2 mRNA in PBMC. PMID:24744472

  20. Sweat rate, salt loss, and fluid intake during an intense on-ice practice in elite Canadian male junior hockey players.

    PubMed

    Palmer, Matthew S; Spriet, Lawrence L

    2008-04-01

    Previous research in many sports suggests that losing ~1%-2% body mass through sweating impairs athletic performance. Elite-level hockey involves high-intensity bursts of skating, arena temperatures are >10 degrees C, and players wear protective equipment, all of which promote sweating. This study examined the pre-practice hydration, on-ice fluid intake, and sweat and sodium losses of 44 candidates for Canada's junior men's hockey team (mean +/- SE age, 18.4 +/- 0.1 y; height, 184.8 +/- 0.9 cm; mass, 89.9 +/- 1.1 kg). Players were studied in groups of 10-12 during 4 intense 1 h practices (13.9 degrees C, 66% relative humidity) on 1 day. Hydration status was estimated by measuring urine specific gravity (USG). Sweat rate was calculated from body mass changes and fluid intake. Sweat sodium concentration ([Na]) was analyzed in forehead sweat patch samples and used with sweat rate to estimate sodium loss. Over 50% of players began practice mildly hypohydrated (USG > 1.020). Sweat rate during practice was 1.8 +/- 0.1 L.h(-1) and players replaced 58% (1.0 +/- 0.1 L.h(-1)) of the sweat lost. Body mass loss averaged 0.8% +/- 0.1%, but 1/3 of players lost more than 1%. Sweat [Na] was 54.2 +/- 2.4 mmol.L(-1) and sodium loss averaged 2.26 +/- 0.17 g during practice. Players drank only water during practice and replaced no sodium. In summary, elite junior hockey players incurred large sweat and sodium losses during an intense practice, but 2/3 of players drank enough to minimize body mass loss. However, 1/3 of players lost more than 1% body mass despite ready access to fluid and numerous drinking opportunities from the coaches. PMID:18347681

  1. On-ice sweat rate, voluntary fluid intake, and sodium balance during practice in male junior ice hockey players drinking water or a carbohydrate-electrolyte solution.

    PubMed

    Palmer, Matthew S; Logan, Heather M; Spriet, Lawrence L

    2010-06-01

    This study evaluated the repeatability of hydration and sweat measurements taken during on-ice hockey practices with players drinking only water, and determined whether having only a carbohydrate-electrolyte solution (CES) to drink during practices decreased fluid intake or affected other hydration and (or) sweat measures. All testing was conducted on elite players of an Ontario Hockey League team (+/-SE; mean age, 17.6 +/- 0.3 years; mean height, 182.9 +/- 1.4 cm; mean body mass, 83.0 +/- 1.7 kg). Players were studied 3 times over the course of 6 weekly on-ice practices (+/-SE; mean playing time, 1.58 +/- 0.07 h; mean temperature, 11.4 +/- 0.8 degrees C; mean relative humidity, 52% +/- 3%). There was strong repeatability of the measured hydration and sweat parameters between 2 similar on-ice practices when players drank only water. Limiting the players to drinking only a CES (as opposed to water) did not decrease fluid intake during practice (+/-SE; mean CES intake, 0.72 +/- 0.07 L.h-1 vs. mean water intake, 0.82 +/- 0.08 L.h-1) or affect sweat rate (1.5 +/- 0.1 L.h-1 vs. 1.5 +/- 0.1 L.h-1), sweat sodium concentration (72.4 +/- 5.6 mmol.L-1 vs. 73.0 +/- 4.4 mmol.L-1), or percent body mass loss (1.1% +/- 0.2% vs. 0.9% +/- 0.2%). Drinking a CES also improved sodium balance (-2.1 +/- 0.2 g.h-1 vs. -2.6 +/- 0.3 g.h-1) and provided the players with a significant carbohydrate (43 +/- 4 g.h-1 vs. 0 +/- 0 g.h-1) during practice. In summary, a single field sweat test during similar on-ice hockey practices in male junior hockey players is sufficient to evaluate fluid and electrolyte balance. Also, a CES does not affect voluntary fluid intake during practice, compared with water, in these players. The CES provided some salt to offset the salt lost in sweat, and carbohydrate, which may help maintain physical and mental performance in the later stages of practice. PMID:20555377

  2. Serum SNTF Increases in Concussed Professional Ice Hockey Players and Relates to the Severity of Postconcussion Symptoms.

    PubMed

    Siman, Robert; Shahim, Pashtun; Tegner, Yelverton; Blennow, Kaj; Zetterberg, Henrik; Smith, Douglas H

    2015-09-01

    Biomarkers for diffuse axonal injury could have utilities for the acute diagnosis and clinical care of concussion, including those related to sports. The calpain-derived ?II-spectrin N-terminal fragment (SNTF) accumulates in axons after traumatic injury and increases in human blood after mild traumatic brain injury (mTBI) in relation to white matter abnormalities and persistent cognitive dysfunction. However, SNTF has never been evaluated as a biomarker for sports-related concussion. Here, we conducted longitudinal analysis of serum SNTF in professional ice hockey players, 28 of whom had a concussion, along with 45 players evaluated during the preseason, 17 of whom were also tested after a concussion-free training game. Compared with preseason levels, serum SNTF increased at 1?h after concussion and remained significantly elevated from 12?h to 6 days, before declining to preseason baseline. In contrast, serum SNTF levels were unchanged after training. In 8 players, postconcussion symptoms resolved within a few days, and in these cases serum SNTF levels were at baseline. On the other hand, for the 20 players withheld from play for 6 days or longer, serum SNTF levels rose from 1?h to 6 days postconcussion, and at 12-36?h differed significantly from the less-severe concussions (p=0.004). Serum SNTF exhibited diagnostic accuracy for concussion, especially so with delayed return to play (area under the curve=0.87). Multi-variate analyses of serum SNTF and tau improved the diagnostic accuracy, the relationship with the delay in return to play, and the temporal window beyond tau alone. These results provide evidence that blood SNTF, a biomarker for axonal injury after mTBI, may be useful for diagnosis and prognosis of sports-related concussion, as well as for guiding neurobiologically informed decisions on return to play. PMID:25419578

  3. Vitamin D status and V[combining dot above]O2peak during a skate treadmill graded exercise test in competitive ice hockey players.

    PubMed

    Fitzgerald, John S; Peterson, Ben J; Warpeha, Joseph M; Wilson, Patrick B; Rhodes, Greg S; Ingraham, Stacy J

    2014-11-01

    Vitamin D status has been associated with cardiorespiratory fitness (CRF) in cross-sectional investigations in the general population. Data characterizing the association between 25-hydroxyvitamin D (25(OH)D) concentration and CRF in athletes are lacking. Junior and collegiate ice hockey players were recruited from the Minneapolis, MN (44.9 N), area during the off-season period (May 16-June 28). The purpose of this study was to examine the cross-sectional association between 25(OH)D concentration and CRF in a sample population of competitive ice hockey players. Circulating 25(OH)D level was assessed from a capillary blood sample analyzed using liquid chromatography-tandem mass spectrometry. V[Combining Dot Above]O2peak during a skate treadmill graded exercise test (GXT) was used to assess CRF. Data on both 25(OH)D concentration and V[Combining Dot Above]O2peak were available for 52 athletes. Insufficient 25(OH)D concentrations were found in 37.7% of the athletes (<32 ngml). Vitamin D status was not significantly associated with any physiological or physical parameter during the skate treadmill GXT. PMID:24832977

  4. Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players.

    PubMed

    Janot, Jeffrey M; Beltz, Nicholas M; Dalleck, Lance D

    2015-09-01

    The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key pointsThe 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed.In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity.Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches can elect to assess player performance off-ice and focus on other uses of valuable ice time for their individual teams. PMID:26336338

  5. Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players

    PubMed Central

    Janot, Jeffrey M.; Beltz, Nicholas M.; Dalleck, Lance D.

    2015-01-01

    The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 ± 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key points The 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed. In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity. Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches can elect to assess player performance off-ice and focus on other uses of valuable ice time for their individual teams. PMID:26336338

  6. Determination of nicotine and nicotine metabolites in urine by hydrophilic interaction chromatography-tandem mass spectrometry: Potential use of smokeless tobacco products by ice hockey players.

    PubMed

    Marclay, François; Saugy, Martial

    2010-11-26

    Consumption of nicotine in the form of smokeless tobacco (snus, snuff, chewing tobacco) or nicotine-containing medication (gum, patch) may benefit sport practice. Indeed, use of snus seems to be a growing trend and investigating nicotine consumption amongst professional athletes is of major interest to sport authorities. Thus, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection and quantification of nicotine and its principal metabolites cotinine, trans-3-hydroxycotinine, nicotine-N'-oxide and cotinine-N-oxide in urine was developed. Sample preparation was performed by liquid-liquid extraction followed by hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) operated in electrospray positive ionization (ESI) mode with selective reaction monitoring (SRM) data acquisition. The method was validated and calibration curves were linear over the selected concentration ranges of 10-10,000 ng/mL for nicotine, cotinine, trans-3-hydroxycotinine and 10-5000 ng/mL for nicotine-N'-oxide and cotinine-N-oxide, with calculated coefficients of determination (R(2)) greater than 0.95. The total extraction efficiency (%) was concentration dependent and ranged between 70.4 and 100.4%. The lower limit of quantification (LLOQ) for all analytes was 10 ng/mL. Repeatability and intermediate precision were ≤9.4 and ≤9.9%, respectively. In order to measure the prevalence of nicotine exposure during the 2009 Ice Hockey World Championships, 72 samples were collected and analyzed after the minimum of 3 months storage period and complete removal of identification means as required by the 2009 International Standards for Laboratories (ISL). Nicotine and/or metabolites were detected in every urine sample, while concentration measurements indicated an exposure within the last 3 days for eight specimens out of ten. Concentrations of nicotine, cotinine, trans-3-hydroxycotinine, nicotine-N'-oxide and cotinine-N-oxide were found to range between 11 and 19,750, 13 and 10,475, 10 and 8217, 11 and 3396, and 13 and 1640 ng/mL, respectively. When proposing conservative concentration limits for nicotine consumption prior and/or during the games (50 ng/mL for nicotine, cotinine and trans-3-hydroxycotinine and 25 ng/mL for nicotine-N'-oxide and cotinine-N-oxide), about half of the hockey players were qualified as consumers. These findings significantly support the likelihood of extensive smokeless nicotine consumption. However, since such conclusions can only be hypothesized, the potential use of smokeless tobacco as a doping agent in ice hockey requires further investigation. PMID:20980010

  7. Psychometric properties and reference values for the ImPACT neurocognitive test battery in a sample of elite youth ice hockey players.

    PubMed

    McKay, Carly D; Brooks, Brian L; Mrazik, Martin; Jubinville, Andrea L; Emery, Carolyn A

    2014-03-01

    This cross-sectional study aimed to determine psychometric properties and reference values for ImPACT in a sample of 704 elite ice hockey players aged 13-17. Baseline ImPACT tests were completed at the beginning of the 2011-2012 season. Players aged 16-17 had better visual motor processing speed, adjusted R(2) = .0522, F(2, 45) = 10.79, ? = 2.87, p < .001, and impulse control, adjusted R = .0185, F(2,45) = 7.46, ? = -1.35, p = .001, than younger players, and girls had greater total symptom ratings than boys (z = -3.47, p = .0005). There were no other sex- or age-related differences in neurocognitive performance, and no effect of previous concussion on ImPACT scores. Reference values with cut-off scores are presented. PMID:24389705

  8. Myelin Water Fraction Is Transiently Reduced after a Single Mild Traumatic Brain Injury – A Prospective Cohort Study in Collegiate Hockey Players

    PubMed Central

    Vavasour, Irene; Shahinfard, Elham; Kolind, Shannon; van Donkelaar, Paul; Taunton, Jack; Li, David; Rauscher, Alexander

    2016-01-01

    Impact-related mild traumatic brain injuries (mTBI) are a major public health concern, and remain as one of the most poorly understood injuries in the field of neuroscience. Currently, the diagnosis and management of such injuries are based largely on patient-reported symptoms. An improved understanding of the underlying pathophysiology of mTBI is urgently needed in order to develop better diagnostic and management protocols. Specifically, dynamic post-injury changes to the myelin sheath in the human brain have not been examined, despite ‘compromised white matter integrity’ often being described as a consequence of mTBI. In this preliminary cohort study, myelin water imaging was used to prospectively evaluate changes in myelin water fraction, derived from the T2 decay signal, in two varsity hockey teams (45 players) over one season of athletic competition. 11 players sustained a concussion during competition, and were scanned at 72 hours, 2 weeks, and 2 months post-injury. Results demonstrated a reduction in myelin water fraction at 2 weeks post-injury in several brain areas relative to preseason scans, including the splenium of the corpus callosum, right posterior thalamic radiation, left superior corona radiata, left superior longitudinal fasciculus, and left posterior limb of the internal capsule. Myelin water fraction recovered to pre-season values by 2 months post-injury. These results may indicate transient myelin disruption following a single mTBI, with subsequent remyelination of affected neurons. Myelin disruption was not apparent in the athletes who did not experience a concussion, despite exposure to repetitive subconcussive trauma over a season of collegiate hockey. These findings may help to explain many of the metabolic and neurological deficits observed clinically following mTBI. PMID:26913900

  9. Descriptive Epidemiology of Collegiate Men's Ice Hockey Injuries: National Collegiate Athletic Association Injury Surveillance System, 19881989 Through 20032004

    PubMed Central

    Agel, Julie; Dompier, Thomas P; Dick, Randall; Marshall, Stephen W

    2007-01-01

    Objective: To review 16 years of National Collegiate Athletic Association (NCAA) injury surveillance data for men's ice hockey and to identify potential areas for injury prevention initiatives. Background: The NCAA began injury surveillance of men's ice hockey during the 19881989 academic year. These data represent all 3 NCAA divisions; the last Division II championship, however, was held during the 19981999 academic year. Main Results: The rate of injury was more than 8 times higher in games than in practices (16.27 versus 1.96 injuries per 1000 athlete-exposures [A-Es], rate ratio = 8.3, 95% confidence interval [CI] = 7.9, 8.8). A significant average annual increase of 1.3% in game injury rates occurred over the sample period ( P = .05), but practice rates stayed static ( P = .77). Preseason practice injury rates were more than twice as high as regular-season practice rates (5.05 versus 1.94 injuries per 1000 A-Es, rate ratio = 2.6, 95% CI = 2.4, 2.9, P < .01). The majority of game and practice injuries occurred to the lower extremity. Knee internal derangement (13.5%) was the most common lower extremity injury reported for games, whereas pelvis and hip muscle strains (13.1%) were the most common injury reported during practices. Player-to-player contact was the most frequent game mechanism of injury (50.0%). The majority of injuries occurred between the blue line and face-off circles (28.0%), in the corner (23.5%), and in the neutral zone (21.4%). Recommendations: Preventive efforts should focus on strategies that limit player-to-player contact in the neutral zone and at the top of the offensive and defensive zones. In addition, clinicians and researchers should identify risk factors and interventions for muscle strains at the pelvis and hip region. PMID:17710172

  10. Myelin Water Fraction Is Transiently Reduced after a Single Mild Traumatic Brain Injury - A Prospective Cohort Study in Collegiate Hockey Players.

    PubMed

    Wright, Alexander D; Jarrett, Michael; Vavasour, Irene; Shahinfard, Elham; Kolind, Shannon; van Donkelaar, Paul; Taunton, Jack; Li, David; Rauscher, Alexander

    2016-01-01

    Impact-related mild traumatic brain injuries (mTBI) are a major public health concern, and remain as one of the most poorly understood injuries in the field of neuroscience. Currently, the diagnosis and management of such injuries are based largely on patient-reported symptoms. An improved understanding of the underlying pathophysiology of mTBI is urgently needed in order to develop better diagnostic and management protocols. Specifically, dynamic post-injury changes to the myelin sheath in the human brain have not been examined, despite 'compromised white matter integrity' often being described as a consequence of mTBI. In this preliminary cohort study, myelin water imaging was used to prospectively evaluate changes in myelin water fraction, derived from the T2 decay signal, in two varsity hockey teams (45 players) over one season of athletic competition. 11 players sustained a concussion during competition, and were scanned at 72 hours, 2 weeks, and 2 months post-injury. Results demonstrated a reduction in myelin water fraction at 2 weeks post-injury in several brain areas relative to preseason scans, including the splenium of the corpus callosum, right posterior thalamic radiation, left superior corona radiata, left superior longitudinal fasciculus, and left posterior limb of the internal capsule. Myelin water fraction recovered to pre-season values by 2 months post-injury. These results may indicate transient myelin disruption following a single mTBI, with subsequent remyelination of affected neurons. Myelin disruption was not apparent in the athletes who did not experience a concussion, despite exposure to repetitive subconcussive trauma over a season of collegiate hockey. These findings may help to explain many of the metabolic and neurological deficits observed clinically following mTBI. PMID:26913900

  11. Position-specific performance indicators that discriminate between successful and unsuccessful teams in elite women's indoor field hockey: implications for coaching.

    PubMed

    Vinson, Don; Peters, Derek M

    2016-02-01

    The aim of this investigation was to establish median performance profiles for the six playing positions in elite women's indoor hockey and then identify whether these position-specific profiles could discriminate between qualifying (top four), mid-table and relegated teams in the 2011-2012 England Hockey premier league. Successful passing in relegated teams was significantly lower (P<0.008) than in mid-table and qualifying teams in four of the five outfield positions. Furthermore, the right backs of qualifying teams demonstrated significantly fewer (P<0.008) unsuccessful passes (x?=15.5 CLs 15.0 and 10.0, respectively) and interceptions (x?=4.0 CLs 4.0 and 3.0, respectively) than relegated teams (x?=19.5 CLs 21.0 and 17.0; x?=7.5 CLs 8.0 and 6.0, respectively). Finally, the right forwards of relegated teams demonstrated significantly fewer (P<0.008) successful interceptions (x?=4.0 CLs 5.0 and 4.0, respectively) than qualifying teams (x?=5.0 CLs 6.0 and 3.0, respectively) and significantly more (P<0.008) unsuccessful interceptions (x?=5.5 CLs 6.0 and 4.0, respectively) than mid-table teams (x?=3.0 CLs 3.0 and 2.0, respectively). Based on these findings, coaches should adapt tactical strategies and personnel deployment accordingly to enhance the likelihood of preparing a qualifying team. Research should build from these data to examine dribbling, pressing and patterns of play when outletting. PMID:26051852

  12. Campus Computing Looks Ahead: Tracking the Digital Puck.

    ERIC Educational Resources Information Center

    Green, Kenneth C.

    2002-01-01

    Examines data from the 2002 Campus Computing Survey to determine trends in information technology in higher education and future possibilities. Discusses Web portals; electronic commerce capabilities, including use of credit cards; budget challenges, including budget cuts; and mobile technology and wireless networks. (LRW)

  13. The 'Patient experience' revolution.

    PubMed

    Hooten, Doug; Zavadsky, Matt

    2014-02-01

    We're arguably at the most pivotal time in our young profession. The ACA has provided EMS an unprecedented opportunity to become a part of the healthcare system, a move that many of us have dreamed about for decades. We need to pay attention to the changing dynamics of the environment in which we operate. The factors that currently impact hospitals, doctors and other healthcare providers will also impact us sooner than we think. Take the time to help shape our future and how we participate in this new healthcare system. It's time to focus on the patient and the patient's experience with our service. Wayne Gretzky said two important things during an interview when he was asked what makes him such a great hockey player. One was, "You miss 100% of the shots you don't take." The other was, "A good hockey player plays where the puck is. A great hockey player plays where the puck is going to be. I skate to where the puck is going to be, not where it has been." Our advice to you is to go ahead, take the shot, get ahead of the other team and focus on improved customer satisfaction sooner rather than later. PMID:24660359

  14. Ojibway Hockey CD ROM in the Making.

    ERIC Educational Resources Information Center

    Williams, Shirley I.

    A shortage of instructional materials and activities is a continual problem for Native language courses, as is making the material relevant to students. The Native way of teaching and learning has always been to have fun. In response to these concerns, a group of language experts at Trent University (Ontario) are developing a CD-ROM for high

  15. The influence of impact object characteristics on impact force and force absorption by mouthguard material.

    PubMed

    Takeda, Tomotaka; Ishigami, Keiichi; Shintaro, Kawamura; Nakajima, Kazunori; Shimada, Atsushi; Regner, Connell Wayne

    2004-02-01

    Most impact force and impact energy absorption tests for mouthguards have used a steel ball in a drop-ball or the pendulum device. However, in reality most sports-related trauma is caused by objects other than the steel ball, e.g. various sized balls, hockey puck, or bat or stick. Also, the elasticity, the velocity and the mass of the object could change the degree and the extent of injuries. In this study, we attempted to measure the impact force from actual sports equipment in order to clarify the exact mechanism of dental-related sports injuries and the protective effects of mouthguards. The present study was conducted using the pendulum impact device and load cell. Impact objects were removable. Seven mobile impact objects were selected for testing: a steel ball, baseball, softball, field hockey ball, ice hockey puck, cricket ball, and wooden baseball bat. The mouthguard material used in this study was a 3-mm-thick Drufosoft (Dreve-Dentamid GmbH, Unna, Germany), and test samples were made of the one-layer type. The peak transmitted forces without mouthguard ranged from the smallest (ice hockey stick, 46.9 kgf) to the biggest (steel ball, 481.6 kgf). The peak transmitted forces were smaller when the mouthguard was attached than without it for all impact materials but the effect was significantly influenced by the object type. The steel ball showed the biggest (62.1%) absorption ability while the wooden bat showed the second biggest (38.3%). The other balls or the puck showed from 0.6 to 6.0% absorbency. These results show that it is important to test the effectiveness of mouthguards on specific types of sports equipment. In future, we may select different materials and mouthguard designs suitable for specific sports. PMID:14998410

  16. ReviewsGCSE Book Review: Modular Science for AQA GCSE Book Review: Modular Science for Edexcel GCSE Book Review: Revise for GCSE Science (Edexcel Modular Foundation and Higher) GCSE Book Review: AQA GCSE Physics, AQA GCSE Physics Additions Book Review: Studying Maths and its Applications Book Review: Medical Physics, 2nd edition Book Review: The Physics of Hockey Book Review: Nine Crazy Ideas In Science Book Review: Light and Dark Talking Point: The Skeptical Environmentalist Places To Visit: Centre for Alternative Technology, Machynlleth, Powys Resources: Sources of Energy Web Watch: Terence, this is stupid stuff...

    NASA Astrophysics Data System (ADS)

    2003-03-01

    GCSE BOOK REVIEWS (162) Modular Science for AQA Modular Science for Edexcel Revise for GCSE Science (Edexcel Modular Foundation and Higher) AQA GCSE Physics, AQA GCSE Physics Additions BOOK REVIEWS (166) Studying Maths and its Applications Medical Physics, 2nd edition The Physics of Hockey Nine Crazy Ideas In Science Light and Dark TALKING POINT (169) The Skeptical Environmentalist PLACES TO VISIT (170) Centre for Alternative Technology, Machynlleth, Powys RESOURCES (172) Sources of Energy WEB WATCH (173) Terence, this is stupid stuff...

  17. A Cool Sport Full of Physics

    NASA Astrophysics Data System (ADS)

    Hach, Alain

    2008-10-01

    Of all sports, ice hockey is possibly the one with the widest array of physics elements in it. The game provides many examples that can bring physics to life in the classroom. Ice hockey (or just "hockey" as many Canadians would say) sees athletes sliding on ice at high speeds and in various ways, shooting and slapping pucks, and colliding against each other. The interaction between the skate blade and the ice is a problem of great physical complexity. The question "Why is ice so slippery?" has puzzled generations of scientists and, surprisingly, clear answers have come relatively recently. There is even some optics involved in hockey: how many sports are watched behind tempered glass (or Plexiglas) windows? The optical and mechanical properties of these materials are worth a physics classroom discussion. In this paper, I will review a few topics discussed at length in my book The Physics of Hockey.1,2 Interested readers may also find additional articles on our website.3

  18. Using action observation to study superior motor performance: a pilot fMRI study.

    PubMed

    Olsson, Carl-Johan; Lundstrm, Peter

    2013-01-01

    The most efficient way to acquire motor skills may be through physical practice. Nevertheless, it has also been shown that action observation may improve motor performance. The aim of the present pilot study was to examine a potential action observation paradigm used to (1) capture the superior performance of expert athletes and (2) capture the underlying neural mechanisms of successful action observation in relation to task experience. We used functional magnetic resonance imaging to measure regional blood flow while presenting videos of a hockey player shooting a puck toward a hockey goal. The videos (a total of 120) where stopped at different time frames with different amount of information provided, creating a paradigm with three different levels of difficulty to decide the fate of a shot. Since this was only a pilot study, we first tested the paradigm behaviorally on six elite expert hockey players, five intermediate players, and six non-hockey playing controls. The results showed that expert hockey players were significantly (p < 0.05) more accurate on deciding the fate of the action compared to the others. Thus, it appears as if the paradigm can capture superior performance of expert athletes (aim 1). We then tested three of the hockey players and three of the controls on the same paradigm in the MRI scanner to investigate the underlying neural mechanisms of successful action anticipation. The imaging results showed that when expert hockey players observed and correctly anticipated situations, they recruited motor and temporal regions of the brain. Novices, on the other hand, relied on visual regions during observation and prefrontal regions during action decision. Thus, the results from the imaging data suggest that different networks of the brain are recruited depending on task experience (aim 2). In conclusion, depending on the level of motor skill of the observer, when correctly anticipating actions different neural systems will be recruited. PMID:24348365

  19. Using action observation to study superior motor performance: a pilot fMRI study

    PubMed Central

    Olsson, Carl-Johan; Lundström, Peter

    2013-01-01

    The most efficient way to acquire motor skills may be through physical practice. Nevertheless, it has also been shown that action observation may improve motor performance. The aim of the present pilot study was to examine a potential action observation paradigm used to (1) capture the superior performance of expert athletes and (2) capture the underlying neural mechanisms of successful action observation in relation to task experience. We used functional magnetic resonance imaging to measure regional blood flow while presenting videos of a hockey player shooting a puck toward a hockey goal. The videos (a total of 120) where stopped at different time frames with different amount of information provided, creating a paradigm with three different levels of difficulty to decide the fate of a shot. Since this was only a pilot study, we first tested the paradigm behaviorally on six elite expert hockey players, five intermediate players, and six non-hockey playing controls. The results showed that expert hockey players were significantly (p < 0.05) more accurate on deciding the fate of the action compared to the others. Thus, it appears as if the paradigm can capture superior performance of expert athletes (aim 1). We then tested three of the hockey players and three of the controls on the same paradigm in the MRI scanner to investigate the underlying neural mechanisms of successful action anticipation. The imaging results showed that when expert hockey players observed and correctly anticipated situations, they recruited motor and temporal regions of the brain. Novices, on the other hand, relied on visual regions during observation and prefrontal regions during action decision. Thus, the results from the imaging data suggest that different networks of the brain are recruited depending on task experience (aim 2). In conclusion, depending on the level of motor skill of the observer, when correctly anticipating actions different neural systems will be recruited. PMID:24348365

  20. Ultra-Compact Motor Controller

    NASA Technical Reports Server (NTRS)

    Townsend, William T.; Cromwell, Adam; Hauptman, Traveler; Pratt, Gill Andrews

    2012-01-01

    This invention is an electronically commutated brushless motor contro ller that incorporates Hall-array sensing in a small, 42-gram packag e that provides 4096 absolute counts per motor revolution position s ensing. The unit is the size of a miniature hockey puck, and is a 44 -pin male connector that provides many I/O channels, including CANbus , RS-232 communications, general-purpose analog and digital I/O (GPI O), analog and digital Hall inputs, DC power input (18-90 VDC, 0-l0 A), three-phase motor outputs, and a strain gauge amplifier.

  1. Augmented Reality Comes to Physics

    NASA Astrophysics Data System (ADS)

    Buesing, Mark; Cook, Michael

    2013-04-01

    Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

  2. Metazoan meiofauna within the oxygen-minimum zone off Chile: Results of the 2001-PUCK expedition

    NASA Astrophysics Data System (ADS)

    Veit-Khler, Gritta; Gerdes, Dieter; Quiroga, Eduardo; Hebbeln, Dierk; Sellanes, Javier

    2009-07-01

    A quantitative study of metazoan meiofauna was carried out at continental shelf and slope stations affected by the oxygen-minimum zone in the eastern South Pacific off Chile. Densities of meiobenthos at the investigated stations off Antofagasta (22S), Concepcin (36S), and Chilo (42S) ranged from 1282.1 to 8847.8 ind 10 cm -2. Oxygen deficiency led only to average abundances, despite higher food availability and freshness at the corresponding sites. Sediment organic carbon, chlorophyll- a, and phaeopigment contents were used as measures of the input from water-column primary production, which accumulated at the oxygen-minimum zone stations. The highest abundances were found at a station with an oxygen content of 0.79 mL L -1, which was slightly elevated from what is defined as oxygen minimum (0.5 mL L -1). The most oxygenated site yielded the lowest densities. Meiofauna assemblages became more diverse with increasing bottom-water oxygenation, whereas nematodes were the most abundant taxon at every station, followed by annelids, copepods, and nauplii.

  3. Video Gaming Promotes Concussion Knowledge Acquisition in Youth Hockey Players

    ERIC Educational Resources Information Center

    Goodman, David; Bradley, Nori L.; Paras, Bradley, Williamson, Ian J.; Bizzochi, James

    2006-01-01

    While the positive uses for video games in an educational setting have also been established, the educational aim is usually made explicit. The goal of this research was to develop a video game wherein the educational aspect was implicitly embedded in the video game, such that the gameing activity remained interesting and relevant. Following a

  4. Pilot study to test effectiveness of video game on reaching performance in stroke.

    PubMed

    Acosta, Ana Maria; Dewald, Hendrik A; Dewald, Jules P A

    2011-01-01

    Robotic systems currently used in upper-limb rehabilitation following stroke rely on some form of visual feedback as part of the intervention program. We evaluated the effect of a video game environment (air hockey) on reaching in stroke with various levels of arm support. We used the Arm Coordination Training 3D system to provide variable arm support and to control the hockey stick. We instructed seven subjects to reach to one of three targets covering the workspace of the impaired arm during the reaching task and to reach as far as possible while playing the video game. The results from this study showed that across subjects, support levels, and targets, the reaching distances achieved with the reaching task were greater than those covered with the video game. This held even after further restricting the mapped workspace of the arm to the area most affected by the flexion synergy (effectively forcing subjects to fight the synergy to reach the hockey puck). The results from this study highlight the importance of designing video games that include specific reaching targets in the workspace compromised by the expression of the flexion synergy. Such video games would also adapt the target location online as a subject's success rate increases. PMID:21674392

  5. CREST modelling of PBX 9502 corner turning experiments at different initial temperatures

    NASA Astrophysics Data System (ADS)

    Whitworth, N. J.

    2014-05-01

    Corner turning is an important problem in regard to detonation wave propagation in TATB-based explosives. Experimentally, a sudden change in the direction of the propagating wave, such as turning a sharp corner, can result in dead-zones being left behind in the corner turn region, with the observed behaviour being particularly sensitive to the initial temperature of the explosive. In this paper, the entropy-dependent CREST reactive burn model is used to simulate corner turning experiments on the TATB-based explosive PBX 9502. Calculated results of double cylinder tests at three different initial temperatures (-54C, ~23C, and 75C), and a "hockey puck" experiment at ambient temperature, are compared to the corresponding test measurements. The results show that the model is able to: (i) calculate persistent dead-zones in PBX 9502 without recourse to any shock desensitisation treatment, and (ii) predict changes in corner turning behaviour with initial temperature using one set of coefficients.

  6. CREST Modelling of PBX 9502 Corner Turning Experiments at Different Initial Temperatures

    NASA Astrophysics Data System (ADS)

    Whitworth, Nicholas

    2013-06-01

    Corner turning is an important problem in regard to detonation wave propagation in TATB-based explosives. Experimentally, a sudden change in direction of the propagating wave, such as turning a sharp corner, can result in dead-zones being left behind in the corner turn region, with the observed behaviour being particularly sensitive to the initial temperature of the explosive. In this paper, the entropy-dependent CREST reactive burn model is used to simulate corner turning experiments on the TATB-based explosive PBX 9502. Calculated results of double cylinder tests at three different initial temperatures (-54C, 25C, and 75C), and a ``hockey puck'' experiment at ambient temperature, are compared to the corresponding test measurements. The results show that the model is able to: (i) calculate persistent dead-zones in PBX 9502 without recourse to any shock desensitisation treatment, and (ii) predict changes in corner turning behaviour with initial temperature using one set of coefficients.

  7. Insulin Delivery System

    NASA Technical Reports Server (NTRS)

    1988-01-01

    When Programmable Implantable Medication System (PIMS) is implanted in human body, it delivers precise programmed amounts of insulin over long periods of time. Mini-Med Technologies has been refining the Technologies since initial development at APL. The size of a hockey puck, and encased in titanium shell, PIMS holds about 2 1/2 teaspoons of insulin at a programmed basal rate. If a change in measured blood sugar level dictates a different dose, the patient can vary the amount of insulin delivered by holding a small radio transceiver over the implanted system and dialing in a specific program held in the PIMS computer memory. Insulin refills are accomplished approximately 4 times a year by hypodermic needle.

  8. Exploring Coaching Actions Based on Developed Values: A Case Study of a Female Hockey Coach

    ERIC Educational Resources Information Center

    Callary, Bettina; Werthner, Penny; Trudel, Pierre

    2013-01-01

    There are few empirical studies that demonstrate how values are developed and how they are linked to coaching actions. There can be a discrepancy between the statement of coaches' values and their actual coaching actions. In order to examine how coaching actions are influenced by values that are developed over a lifetime, the purpose of this

  9. The Validity and Reliability of a Performance Assessment Procedure in Ice Hockey

    ERIC Educational Resources Information Center

    Nadeau, Luc; Richard, Jean-Francois; Godbout, Paul

    2008-01-01

    Background: Coaches and physical educators must obtain valid data relating to the contribution of each of their players in order to assess their level of performance in team sport competition. This information must also be collected and used in real game situations to be more valid. Developed initially for a physical education class context, the…

  10. Coach Selections and the Relative Age Effect in Male Youth Ice Hockey

    ERIC Educational Resources Information Center

    Hancock, David J.; Ste-Marie, Diane M.; Young, Bradley W.

    2013-01-01

    Relative age effects (RAEs; when relatively older children possess participation and performance advantages over relatively younger children) are frequent in male team sports. One possible explanation is that coaches select players based on physical attributes, which are more likely witnessed in relatively older athletes. Purpose: To determine if…

  11. Coach Selections and the Relative Age Effect in Male Youth Ice Hockey

    ERIC Educational Resources Information Center

    Hancock, David J.; Ste-Marie, Diane M.; Young, Bradley W.

    2013-01-01

    Relative age effects (RAEs; when relatively older children possess participation and performance advantages over relatively younger children) are frequent in male team sports. One possible explanation is that coaches select players based on physical attributes, which are more likely witnessed in relatively older athletes. Purpose: To determine if

  12. An Examination of the Relative Age Effect in Developmental Girls' Hockey in Ontario

    ERIC Educational Resources Information Center

    Smith, Kristy L.; Weir, Patricia L.

    2013-01-01

    The relative age effect (RAE) suggests that athletes may be provided with greater opportunities for success depending on the position of their birthdate in a sport's selection year. While the effect has been well established in men's sports, less is known about women's sports. This study examined the RAE in developmental girls'

  13. Hockey Night in Canada and Waltzing Matilda: Examining Culture in a Global Classroom.

    ERIC Educational Resources Information Center

    Jacobsen, Michele; Tate, Joanne

    This paper, the result of a collaboration between professors at the University of Calgary in Canada and Ararat Community College in Victoria (Australia), was presented at the 2001 Teaching the in Community Colleges Conference, "Teaching and Learning: What Have We Discovered and Where Are We Headed?" In this paper, the authors describe their…

  14. The Validity and Reliability of a Performance Assessment Procedure in Ice Hockey

    ERIC Educational Resources Information Center

    Nadeau, Luc; Richard, Jean-Francois; Godbout, Paul

    2008-01-01

    Background: Coaches and physical educators must obtain valid data relating to the contribution of each of their players in order to assess their level of performance in team sport competition. This information must also be collected and used in real game situations to be more valid. Developed initially for a physical education class context, the

  15. Protein carbonyl levels correlate with performance in elite field hockey players.

    PubMed

    Rosa-Lima, Frederico Luis; Lannes, Luiz; Viana-Gomes, Diego; Pierucci, Anna Paola T R; Salerno, Vernica P

    2015-07-01

    Excess and incorrectly selected exercise can degrade athletic performance from an imbalance in redox homeostasis and oxidative stress, but well-planned training and nutrition can improve antioxidant capacity. The aim of the study was to investigate how nutrient intake could influence oxidative stress and cell lesion biomarkers after 5 days of training followed by a game. Blood was collected from 10 athletes at the start of training (basal), after training (pre-game), and postgame. Their acceleration capacity also was measured pre- and postgame. Blood analysis showed an increase in lactate concentration postgame (13%) and total antioxidant capacity increased both pre-game (13.1%) and postgame (12.7%), all in comparison with basal levels. An oxidative stress marker, protein carbonyl (PC), increased 3-fold over the course of the game, which correlated with a decreased acceleration (r = 0.749). For biomarkers of tissue damage, creatine kinase and aspartate transaminase (AST) increased postgame by 150% and 75%, respectively. The AST variation had a high negative correlation with energy and carbohydrate consumption and a moderate correlation with lipid and vitamin C intake. Protein intake had a positive but moderate correlation with reduced glutathione. The observed correlations suggest that nutritional monitoring can improve exercise physiological homeostasis and that PC serves as a good biomarker for oxidative stress and performance loss. PMID:25962716

  16. Heat transfer at the mold-metal interface in permanent mold casting of aluminum alloys project. Quarterly project status report, April 1--June 30, 1998

    SciTech Connect

    Pehlke, R.D.; Hao, S.W.

    1998-06-30

    Extensive progress in development of an HTC (heat transfer coefficient) Evaluator and in the preparation of the experiments at CMI and Amcast have been achieved in the last three months. The interface of the HTC Evaluator has been developed in Visual C++ for the PC platform. It provides a tool to collect and store the published data on heat transfer coefficients in a database for further analysis. It also supports the mathematical model for evaluation of heat transfer coefficients. More than 100 papers related to this project have been cited and most of them have been collected. The preparation of the experiments at CMI is almost completed. A hockey-puck mold has been selected for the experiments for squeeze casting and semi-solid casting. A direct cavity pressure measurement system was purchased from Kistler. The pressure probes and data acquisition software as well as the necessary accessories have been delivered. The instrumented mold modification has been designed and the modifications completed. At Amcast Automotive, a new wheel-like mold for low-pressure permanent mold casting was designed. The CAD file for mold fabrication has been generated. The modeling of the casting has been done. An extensive survey on the ultrasonic gap formation measurement was fulfilled. It is concluded that the ultrasonic probe is capable of measuring a gap under the authors` casting conditions. In the last three months, four project meetings has been organized and held with the industrial partners.

  17. Square lattice honeycomb tri-carbide fuels for 50 to 250 KN variable thrust NTP design

    NASA Astrophysics Data System (ADS)

    Anghaie, Samim; Knight, Travis; Gouw, Reza; Furman, Eric

    2001-02-01

    Ultrahigh temperature solid solution of tri-carbide fuels are used to design an ultracompact nuclear thermal rocket generating 950 seconds of specific impulse with scalable thrust level in range of 50 to 250 kilo Newtons. Solid solutions of tri-carbide nuclear fuels such as uranium-zirconium-niobium carbide. UZrNbC, are processed to contain certain mixing ratio between uranium carbide and two stabilizing carbides. Zirconium or niobium in the tri-carbide could be replaced by tantalum or hafnium to provide higher chemical stability in hot hydrogen environment or to provide different nuclear design characteristics. Recent studies have demonstrated the chemical compatibility of tri-carbide fuels with hydrogen propellant for a few to tens of hours of operation at temperatures ranging from 2800 K to 3300 K, respectively. Fuel elements are fabricated from thin tri-carbide wafers that are grooved and locked into a square-lattice honeycomb (SLHC) shape. The hockey puck shaped SLHC fuel elements are stacked up in a grooved graphite tube to form a SLHC fuel assembly. A total of 18 fuel assemblies are arranged circumferentially to form two concentric rings of fuel assemblies with zirconium hydride filling the space between assemblies. For 50 to 250 kilo Newtons thrust operations, the reactor diameter and length including reflectors are 57 cm and 60 cm, respectively. Results of the nuclear design and thermal fluid analyses of the SLHC nuclear thermal propulsion system are presented. .

  18. Employment Law, Negotiation, and the Business Environment: A Cooperative Collective Bargaining Negotiation of the National Hockey League Lockout of 2004

    ERIC Educational Resources Information Center

    Ciocchetti, Corey A.

    2008-01-01

    Employment law is a "must-cover" subject in business environment courses. Comparing the plethora of topics requiring coverage with the limited time devoted to employment law during a typical academic term, other important employment subjects--such as negotiation and collective bargaining--commonly receive short shrift. This article offers a

  19. Measurement of Hybrid III Head Impact Kinematics Using an Accelerometer and Gyroscope System in Ice Hockey Helmets.

    PubMed

    Allison, Mari A; Kang, Yun Seok; Maltese, Matthew R; Bolte, John H; Arbogast, Kristy B

    2015-08-01

    Helmet-based instrumentation is used to study the biomechanics of concussion. The most extensively used systems estimate rotational acceleration from linear acceleration, but new instrumentation measures rotational velocity using gyroscopes, potentially reducing error. This study compared kinematics from an accelerometer and gyroscope-containing system to reference measures. A Hybrid III (HIII) adult male anthropometric test device head and neck was fit with two helmet brands, each instrumented with gForce Tracker (GFT) sensor systems in four locations. Helmets were impacted at various speeds and directions. Regression relationships between GFT-measured and reference peak kinematics were quantified, and influence of impact direction, sensor location, and helmet brand was evaluated. The relationship between the sensor output and the reference acceleration/velocity experienced by the head was strong. Coefficients of determination for data stratified by individual impact directions ranged from 0.77 to 0.99 for peak linear acceleration and from 0.78 to 1.0 for peak rotational velocity. For the data from all impact directions combined, coefficients of determination ranged from 0.60 to 0.80 for peak resultant linear acceleration and 0.83 to 0.91 for peak resultant rotational velocity. As expected, raw peak resultant linear acceleration measures exhibited large percent differences from reference measures. Adjustment using regressions resulted in average absolute errors of 10-15% if regression adjustments were done by impact direction or 25-40% if regressions incorporating data from all impact directions were used. Average absolute percent differences in raw peak resultant rotational velocity were much lower, around 10-15%. It is important to define system accuracy for a particular helmet brand, sensor location, and impact direction in order to interpret real-world data. PMID:25476162

  20. Heat transfer at the mold-metal interface in permanent mold casting of aluminum alloys project. Annual project status report for the period October 1, 1997 to September 30, 1998

    SciTech Connect

    Pehlke, R.D.; Hao, S.W.

    1998-09-30

    In the first year of this three-year project, substantial progress has been achieved. This project on heat transfer coefficients in metal permanent mold casting is being conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigations of squeeze casting and semi-solid casting at CMI-Tech Center, and the experimental investigation of low pressure permanent mold casting at Amcast Automotive. U-M did an initial geometry which was defined for ProCAST to solve, and then a geometry half the size was defined and solved using the same boundary conditions. A conceptual mold geometry was examined and is represented as an axisymmetric element.Furthermore, the influences of the localized heat transfer coefficients on the casting process were carefully studied. The HTC Evaluator has been proposed and initially developed by the U-M team. The Reference and the Database Modules of the HTC Evaluator have been developed, and extensively tested. A series of technical barriers have been cited and potential solutions have been surveyed. At the CMI-Tech Center, the Kistler direct cavity pressure measurement system has been purchased and tested. The calibrations has been evaluated. The probe is capable of sensing a light finger pressure. The experimental mold has been designed and modified. The experimental mold has been designed and modified. The first experiment is scheduled for October 14, 1998. The geometry of the experimental hockey-puck casting has been given to the U-M team for numerical analysis.

  1. Modeling Hemispheric Detonation Experiments in 2-Dimensions

    SciTech Connect

    Howard, W M; Fried, L E; Vitello, P A; Druce, R L; Phillips, D; Lee, R; Mudge, S; Roeske, F

    2006-06-22

    Experiments have been performed with LX-17 (92.5% TATB and 7.5% Kel-F 800 binder) to study scaling of detonation waves using a dimensional scaling in a hemispherical divergent geometry. We model these experiments using an arbitrary Lagrange-Eulerian (ALE3D) hydrodynamics code, with reactive flow models based on the thermo-chemical code, Cheetah. The thermo-chemical code Cheetah provides a pressure-dependent kinetic rate law, along with an equation of state based on exponential-6 fluid potentials for individual detonation product species, calibrated to high pressures ({approx} few Mbars) and high temperatures (20000K). The parameters for these potentials are fit to a wide variety of experimental data, including shock, compression and sound speed data. For the un-reacted high explosive equation of state we use a modified Murnaghan form. We model the detonator (including the flyer plate) and initiation system in detail. The detonator is composed of LX-16, for which we use a program burn model. Steinberg-Guinan models5 are used for the metal components of the detonator. The booster and high explosive are LX-10 and LX-17, respectively. For both the LX-10 and LX-17, we use a pressure dependent rate law, coupled with a chemical equilibrium equation of state based on Cheetah. For LX-17, the kinetic model includes carbon clustering on the nanometer size scale.

  2. Detonation waves in triaminotrinitrobenzene

    SciTech Connect

    Tarver, C.M.; Kury, J.W.; Breithaupt, R.D.

    1997-10-01

    Fabry{endash}Perot laser interferometry is used to obtain nanosecond time resolved particle velocity histories of the free surfaces of copper, tantalum, or magnesium disks driven by detonating triaminotrinitrobenzene (TATB)-based charges and of the interfaces between detonating TATB and transparent salt crystals. Detonation reaction zone profiles are measured for self-sustaining detonation waves propagating through various thicknesses of LX-17 (92.5{percent} TATB and 7.5{percent} KelF binder) and pure ultrafine particle size TATB. The experimental records are compared to particle velocity histories calculated with the DYNA2D hydrodynamic code using the ignition and growth reactive flow model. The calculations yield excellent agreement with the experimental records for LX-17 using an unreacted von Neumann spike pressure of 33.7 GPa, a reaction rate law which releases 70{percent} of the chemical energy within 100 ns, and the remaining 30{percent} over 300 additional ns, and a reaction product equation of state fit to cylinder test and supracompression data with a Chapman{endash}Jouguet (C{endash}J) pressure of 25 GPa. The late time energy release is attributed to diffusion controlled solid carbon particle formation. Ultrafine TATB, pressed to a lower density (1.80g/cm{sup 3}) than LX-17 (1.905g/cm{sup 3}), exhibits lower unreacted spike and C{endash}J pressures than LX-17 but similar reaction rates. {copyright} {ital 1997 American Institute of Physics.}

  3. Establishing the Test-Retest Reliability & Concurrent Validity for the Repeat Ice Skating Test (RIST) in Adolescent Male Ice Hockey Players

    ERIC Educational Resources Information Center

    Power, Allan; Faught, Brent E.; Przysucha, Eryk; McPherson, Moira; Montelpare, William

    2012-01-01

    In this study the authors examine the test-retest reliability and concurrent validity of the Repeat Ice Skating Test (RIST). This was an on-ice field anaerobic test that measured average peak power and was validated with 3 anaerobic lab tests: (a) vertical jump, (b) the Margaria-Kalamen stair test, and (c) the Wingate Anaerobic Test. The

  4. Establishing the Test-Retest Reliability & Concurrent Validity for the Repeat Ice Skating Test (RIST) in Adolescent Male Ice Hockey Players

    ERIC Educational Resources Information Center

    Power, Allan; Faught, Brent E.; Przysucha, Eryk; McPherson, Moira; Montelpare, William

    2012-01-01

    In this study the authors examine the test-retest reliability and concurrent validity of the Repeat Ice Skating Test (RIST). This was an on-ice field anaerobic test that measured average peak power and was validated with 3 anaerobic lab tests: (a) vertical jump, (b) the Margaria-Kalamen stair test, and (c) the Wingate Anaerobic Test. The…

  5. Sports and Exercise Safety

    MedlinePLUS

    ... when batting. Goggles are often worn for soccer, basketball, racquet sports, snowboarding, street hockey, and baseball and ... head injury is a risk, such as football, basketball, hockey, volleyball, martial arts, boxing, or wrestling. Mouthguards ...

  6. Preventing Children's Sports Injuries

    MedlinePLUS

    ... well. For example, they should wear helmets for baseball , softball, bicycle riding , and hockey . They also should ... racquet sports, field hockey, lacrosse, basketball , softball, and baseball, ask about any protective eyewear, like shatterproof glasses. ...

  7. The effect of metal particle size on blast performance of RDX and TATB based explosives

    NASA Astrophysics Data System (ADS)

    Davis, Jeffery; Miller, Phillip

    2001-06-01

    This paper discusses the role that particle size of aluminum has on the internal blast performance of explosives. Tests were performed using a small sealed chamber and a larger open-ended shock tube. Two sets of explosive formulations were tested. One is TATB based and the other RDX. The TATB was an aluminized LX-17 formulation while the RDX was based on PBXN-109. The Al particle size examined was 20 micron and 150 nanometer in pressed compositions. PBXN-109 and LX-17 were also tested. A noticeable difference in the internal blast pressure was observed between the 20 micron and 150 nm Al. The experimental results compare favorably with modeling work performed

  8. SHOCK INITIATION EXPERIMENTS ON THE TATB BASED EXPLOSIVE RX-03-GO WITH IGNITION AND GROWTH MODELING

    SciTech Connect

    Vandersall, K S; Garcia, F; Tarver, C M

    2009-06-23

    Shock initiation experiments on the TATB based explosive RX-03-GO (92.5% TATB, 7.5% Cytop A by weight) were performed to obtain in-situ pressure gauge data, characterize the run-distance-to-detonation behavior, and calculate Ignition and Growth modeling parameters. A 101 mm diameter propellant driven gas gun was utilized to initiate the explosive sample with manganin piezoresistive pressure gauge packages placed between sample slices. The RX-03-GO formulation utilized is similar to that of LX-17 (92.5% TATB, 7.5% Kel-f by weight) with the notable differences of a new binder material and TATB that has been dissolved and recrystallized in order to improve the purity and morphology. The shock sensitivity will be compared with that of prior data on LX-17 and other TATB formulations. Ignition and Growth modeling parameters were obtained with a reasonable fit to the experimental data.

  9. A rehabilitation tool for functional balance using altered gravity and virtual reality

    PubMed Central

    Oddsson, Lars IE; Karlsson, Robin; Konrad, Janusz; Ince, Serdar; Williams, Steve R; Zemkova, Erika

    2007-01-01

    Background There is a need for effective and early functional rehabilitation of patients with gait and balance problems including those with spinal cord injury, neurological diseases and recovering from hip fractures, a common consequence of falls especially in the elderly population. Gait training in these patients using partial body weight support (BWS) on a treadmill, a technique that involves unloading the subject through a harness, improves walking better than training with full weight bearing. One problem with this technique not commonly acknowledged is that the harness provides external support that essentially eliminates associated postural adjustments (APAs) required for independent gait. We have developed a device to address this issue and conducted a training study for proof of concept of efficacy. Methods We present a tool that can enhance the concept of BWS training by allowing natural APAs to occur mediolaterally. While in a supine position in a 90 deg tilted environment built around a modified hospital bed, subjects wear a backpack frame that is freely moving on air-bearings (cf. puck on an air hockey table) and attached through a cable to a pneumatic cylinder that provides a load that can be set to emulate various G-like loads. Veridical visual input is provided through two 3-D automultiscopic displays that allow glasses free 3-D vision representing a virtual surrounding environment that may be acquired from sites chosen by the patient. Two groups of 12 healthy subjects were exposed to either strength training alone or a combination of strength and balance training in such a tilted environment over a period of four weeks. Results Isokinetic strength measured during upright squat extension improved similarly in both groups. Measures of balance assessed in upright showed statistically significant improvements only when balance was part of the training in the tilted environment. Postural measures indicated less reliance on visual and/or increased use of somatosensory cues after training. Conclusion Upright balance function can be improved following balance specific training performed in a supine position in an environment providing the perception of an upright position with respect to gravity. Future studies will implement this concept in patients. PMID:17623080

  10. Miniature Free-Flying Magnetometer Utilizing System-On-A-Chip Technology

    NASA Astrophysics Data System (ADS)

    Blaes, B. R.; Eyre, F. B.

    2001-01-01

    Four Free-Flying Magnetometers (FFMs), developed at the Jet Propulsion Laboratory (JPL) for the Enstrophy mission, were successfully deployed from the payload of a sounding rocket launched from Poker Flats, Alaska on February 11, 1999. The FFMs functioned successfully by synchronously measuring the vector magnetic field at 4 points separate from the payload and at relative distances up to 3 km, and communicated their data, in bursts, to the ground. This is the first time synchronized in-situ multipoint measurements of the Earth's magnetic field utilizing miniature spin-stabilized "sensorcraft" have been performed. The data they provided have enabled, for the first time, the direct measure of field-aligned current density and are enabling new science by determining the fine-scale structure of the currents in the Earth's ionosphere involved in the production of aurora. These proof-of-concept "hockey puck" (80 mm diameter, 38 mm height, 250 gram mass) FFMs were built using off-the-shelf commercial, industrial, and military grade surface-mount electronic components. Radiation-hard electronics was not required for the Enstrophy mission's short sub-orbital flight. The successful design, implementation, and flight demonstration of this 1st generation FFM design has provided a solid base for further development of a 2nd generation FFM design for planetary science applications. A reliable ultra-miniature radiation-hard 2nd-generation FFM utilizing System-On-A-Chip (SOAC) technologies is proposed. This design would be targeted for long-term planetary missions to investigate magnetospheric field configurations in regions having small-scale structure and to separate spatial and temporal variations. A fleet of short-lived (expendable) FFMs would be deployed into a targeted region to gather multiprobe vector magnetic field data. The FFMs would be ejected from a parent spacecraft at a speed of a few m/sec and would cover spatial volumes of order tens of kilometers for times of order one hour. The parent spacecraft would carry a sufficient number of FFMs for multiple deployments. Additional information is contained in the original extended abstract.

  11. Ultra-Compact Motor Controller

    NASA Technical Reports Server (NTRS)

    Townsend, William T.; Crowell, Adam; Hauptman, Traveler; Pratt, Gill Andrews

    2012-01-01

    This invention is an electronically commutated brushless motor controller that incorporates Hall-array sensing in a small, 42-gram package that provides 4096 absolute counts per motor revolution position sensing. The unit is the size of a miniature hockey puck, and is a 44-pin male connector that provides many I/O channels, including CANbus, RS-232 communications, general-purpose analog and digital I/O (GPIO), analog and digital Hall inputs, DC power input (18-90 VDC, 0-l0 A), three-phase motor outputs, and a strain gauge amplifier. This controller replaces air cooling with conduction cooling via a high-thermal-conductivity epoxy casting. A secondary advantage of the relatively good heat conductivity that comes with ultra-small size is that temperature differences within the controller become smaller, so that it is easier to measure the hottest temperature in the controller with fewer temperature sensors, or even one temperature sensor. Another size-sensitive design feature is in the approach to electrical noise immunity. At a very small size, where conduction paths are much shorter than in conventional designs, the ground becomes essentially isopotential, and so certain (space-consuming) electrical noise control components become unnecessary, which helps make small size possible. One winding-current sensor, applied to all of the windings in fast sequence, is smaller and wastes less power than the two or more sensors conventionally used to sense and control winding currents. An unexpected benefit of using only one current sensor is that it actually improves the precision of current control by using the "same" sensors to read each of the three phases. Folding the encoder directly into the controller electronics eliminates a great deal of redundant electronics, packaging, connectors, and hook-up wiring. The reduction of wires and connectors subtracts substantial bulk and eliminates their role in behaving as EMI (electro-magnetic interference) antennas. A shared knowledge by each motor controller of the state of all the motors in the system at 500 Hz also allows parallel processing of higher-level kinematic matrix calculations.

  12. Lightning-resistant, low-inductance detonator cables

    SciTech Connect

    Druce, R.L.; Lee, R.S.; Moua, K.

    1994-04-01

    A lightning strike on a flat detonator cable in close proximity to a high explosive (HE) main charge poses a possible detonation hazard if the electrical explosion of the cable launches the dielectric cover coat of the cable at a high enough velocity to shock-initiate the HE. The detonator cable for the W87 system has been demonstrated to be incapable of initiating LX-17 main-charge explosive even for a 99 percentile negative lightning strike (1). The W87 cable is a relatively high inductance cable, unsuitable for use with low-inductance firesets. We have performed tests on a low-inductance cable designed for the W89 program, which show it to be marginal in its ability to withstand a lightning strike without the possibility of initiating a heated LX-17 main charge HE. A new cable design, proposed by R.E. Lee of LLNL has been tested and shown to be capable of withstanding a 99 percentile negative lightning strike without initiating LX-17 heated to 250{degree}C.

  13. The effects of confinement and temperature on the shock sensitivity of solid explosives

    SciTech Connect

    Forbes, J W; Tarver, C M; Urtiew, Garcia, F

    1998-08-17

    The effects of heavy steel confinement on the shock sensitivity of pressed solid high explosives heated to temperatures close to thermal explosion conditions were quantitatively measured. Cylindrical flyer plates accelerated by a 101 mm diameter gas gun impacted preheated explosive charges containing multiple embedded manganin pressure gauges. The high explosive compositions tested were LX-04-01 (85 wt.% HMX and 15 wt.% Viton A) heated to 170 C and LX-17 (92.5 wt.% TATB and 7.5 wt.% Kel-F) heated to 250 C. Ignition and Growth reactive flow models for heated, heavily confined LX-04-01 and LX-17 were formulated based on the measured pressure histories. LX-17 at 250 C is considerably less shock sensitive when confined by steel than when confined by aluminum or unconfined. LX-04-01 at 170 C is only slightly less shock sensitive when confined by steel than when it is unconfined. The confinement effect is smaller in LX-04-01, because HMX particle growth i s much less than that of TATB.

  14. Reactive Flow Modeling of the Interaction of TATB Detonation Waves with Inert Materials

    SciTech Connect

    Tarver, C M; McGuire, E M

    2002-07-01

    The Ignition & Growth model for the shock initiation and detonation of solid explosives is applied to calculating the main features of detonation waves in the triaminotrinitrobenzene (TATB) based high explosives LX-17, PBX 9502 and EDC-35. Under detonation conditions, TATB based explosives exhibit reaction zone lengths of 2 to 3 mm depending on the interactions between the detonation wave and the surrounding inert materials. This paper describes comparisons of Ignition & Growth calculations with data from several two- and three-dimensional experiments in which various materials are used to confine the TATB based explosives. The calculated unconfined failure diameters of PBX 9502 are normalized to the measured values at five initial temperatures. Failure diameters for LX-17 are then estimated by changing only the fraction ignited near the shock front. Fabry-Perot data on spherically divergent LX-17 snowball experiments is also compared to calculations. Calculated detonation velocities, wave front curvatures, and metal acceleration velocities are compared to experimental detonation data for TATB-based high explosives in tantalum, copper, PMMA, brass, and beryllium confinement. Three-dimensional prism failure test results on PBX 9502 are also stimulated using the ALE3D code.

  15. Plutonium Immobilization Can Loading Conceptual Design

    SciTech Connect

    Kriikku, E.

    1999-05-13

    'The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses the Plutonium Immobilization can loading conceptual design and includes a process block diagram, process description, preliminary equipment specifications, and several can loading issues. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.'

  16. Development of the Direct Fabrication Process for Plutonium Immobilization

    SciTech Connect

    Congdon, J.W.

    2001-07-10

    The current baseline process for fabricating pucks for the Plutonium Immobilization Program includes granulation of the milled feed prior to compaction. A direct fabrication process was demonstrated that eliminates the need for granulation.

  17. Racial and Gender Report Card, 2003: A Comprehensive Analysis of the Hiring Practices of the National Basketball Association, National Football League, National Hockey League, Major League Baseball, Major League Soccer, Women's National Basketball Association, and NCAA and Its Member Institutions.

    ERIC Educational Resources Information Center

    Lapchick, Richard E.

    This is the 12th issue of the "Racial and Gender Report Card," which assesses hiring practices of women and people of color in U.S. professional and amateur sports and sporting organizations. It considers the composition of players, coaches, and front office/athletic department employees in the leading sports organizations. Each organization is

  18. Jack Rabbit Pretest 2021E PT6 Photonic Doppler Velocimetry Data Volume 6 Section 1

    SciTech Connect

    Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

    2008-06-25

    The Jack Rabbit Pretest (PT) 2021E PT6 experiment was fired on April 1, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT6, 160 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 20, 30, 35, 45, 55, 65, 75 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 54.2 microseconds at 30 millimeters. The latest PDV signal extinction time was 64.5 microseconds at the central axis. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 55 millimeters at 14.1 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1860 meters per second. At 55 millimeters the last measured velocity was 2408 meters per second. The low-to-high velocity ratio was 0.77. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 227 kilobars at 20.1 microseconds, indicating a late time chemical reaction in the LX-17 dead-zone. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 1.7 microseconds.

  19. Detonator cable initiation system safety investigation: Consequences of energizing the detonator and actuator cables

    SciTech Connect

    Osher, J.; Chau, H.; Von Holle, W.

    1994-03-01

    This study was performed to explore and assess the worst-case response of a W89-type weapons system, damaged so as to expose detonator and/or detonator safing strong link (DSSL) cables to the most extreme, credible lightning-discharge, environment. The test program used extremely high-current-level, fast-rise-time (1- to 2-{mu}s) discharges to simulate lightning strikes to either the exposed detonator or DSSL cables. Discharges with peak currents above 700 kA were required to explode test sections of detonator cable and launch a flyer fast enough potentially to detonate weapon high explosive (HE). Detonator-safing-strong-link (DSSL) cables were exploded in direct contact with hot LX-17 and Ultrafine TATB (UFTATB). At maximum charging voltage, the discharge system associated with the HE firing chamber exploded the cables at more than 600-kA peak current; however, neither LX-17 nor UFTATB detonated at 250{degree}C. Tests showed that intense surface arc discharges of more than 700 kA/cm in width across the surface of hot UFTATB [generally the more sensitive of the two insensitive high explosives (IHE)] could not initiate this hot IHE. As an extension to this study, we applied the same technique to test sections of the much-narrower but thicker-cover-layer W87 detonator cable. These tests were performed at the same initial stored electrical energy as that used for the W89 study. Because of the narrower cable conductor in the W87 cables, discharges greater than 550-kA peak current were sufficient to explode the cable and launch a fast flyer. In summary, we found that lightning strikes to exposed DSSL cables cannot directly detonate LX-17 or UFTATB even at high temperatures, and they pose no HE safety threat.

  20. Bigplate: an oblique angle explosive EOS test

    SciTech Connect

    Anderson, S; Avara, R; Fried, L; Janzen, J; McGuire, E; Souers, P C; Wu, B

    1998-04-16

    Bigplate is an advanced explosive equation of state (EOS) test. It consists of a point detonator driving a large disc (100 mm radius) of explosive, which pushes a 0.5 mm thick copper or tantalum plate. The plate is observed by a five-beam Fabry-Perot interferometer, which has beams at 0, 10, 20,40 and 80 mm on the plate. A short Fabry gives the jump-off to high accuracy; a long Fabry runs out to I0-15 microsec. A detailed error analysis is given, with the final velocity measurements considered good to 0.066 mm/microsec. Jump-offs are measured to 0.01-0.02 microsec. Spall is seen in all shots, which creates a time delay on both the first and second velocity plateaus. A 0.1 microsec delay in jump-off of unknown origin is also seen at 80 mm. In order of decreasing explosive ideality, the explosives tired have been LX-14, LX-04 and LX-17. To partially negate the time delays, the data and code runs are overlaid at each radial position between the first and second plateaus. Traditional JWL's model LX-14 and LX-04 within accuracy, but not so for LX-17. The spall may be partly modeled using the pmin model but high resolution zoning is required. At longer times, spall does not appear to affect the explosive energetics. Because it includes diagonal zone crossing, Bigplate occupies a location between simple plate and cylinder tests and truly complex geometries. Hence, an EOS that fails Bigplate is not likely to move on to more complex issues. Bigplate is an excellent test bed for radically new EOS's, and the initial LX-17 runs done with Equilibrium and KINETIC CHEETAH are promising.

  1. Nontraditional Games in a Foreign Environment.

    ERIC Educational Resources Information Center

    Cross, Thomas S.

    A study investigated students' reactions to the addition of nontraditional games (played in and traditional to another country) to the physical education curriculum. Seventh grade students in Australia were introduced to game development, skills, and present status of two sports, 'Midget' Hockey, a modified version of Canadian ice hockey, and

  2. The Effect of Role Ambiguity on Competitive State Anxiety.

    ERIC Educational Resources Information Center

    Beauchamp, Mark R.; Bray, Steven R.; Eys, Mark A.; Carron, Albert V.

    2003-01-01

    Investigated the relationship between role ambiguity and precompetition state anxiety among high school athletes playing field hockey. Surveys of male and female field hockey players in the United Kingdom indicated that ambiguity concerning the scope of one's offensive responsibilities was predictive cognitive state anxiety, while ambiguity

  3. Safety in Team Sports. Sports Safety Series, Monograph No. 3.

    ERIC Educational Resources Information Center

    Borozne, Joseph, Ed.; And Others

    This monograph examines methods of promoting safe practices in the conduct of selected team sports with the aim of reducing and eliminating the occurrance of injuries. The team sports discussed are baseball and softball, basketball, field hockey, tackle football, touch and flag football, ice hockey, lacrosse, and soccer. (MJB)

  4. 75 FR 24951 - Granting of Request for Early Termination of the Waiting Period Under the Premerger Notification...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    .... 20100386 G Ipsos SA. G Pilot Group LP. G OTX Corporation. 20100396 G Jeffrey Vinik. G Lightning Investment Holdings L.P. G Lightning Properties, Ltd. G Palace Florida Properties L.P. G Lightning Hockey GP LLC. G Tampa Bay Arena, L.P. G Lightning Hockey LP. G Lightning Real Estate Investment GP LLC. 20100398 G...

  5. 75 FR 11538 - Granting of Request for Early Termination of the Waiting Period Under the Premerger Notification...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-11

    ... Pilot Group LP G OTX Corporation 20100396 G Jeffrey Vinik G Lightning Investment Holdings L.P. G Lightning Properties, Ltd. G Palace Florida Properties L.P. G Lightning Hockey GP LLC G Tampa Bay Arena, L.P. G Lightning Hockey LP G Lightning Real Estate Investment GP LLC 20100398 G Roark Capital Partners...

  6. The Effect of Role Ambiguity on Competitive State Anxiety.

    ERIC Educational Resources Information Center

    Beauchamp, Mark R.; Bray, Steven R.; Eys, Mark A.; Carron, Albert V.

    2003-01-01

    Investigated the relationship between role ambiguity and precompetition state anxiety among high school athletes playing field hockey. Surveys of male and female field hockey players in the United Kingdom indicated that ambiguity concerning the scope of one's offensive responsibilities was predictive cognitive state anxiety, while ambiguity…

  7. Team Sports: A Place for Primary Care

    PubMed Central

    Hancock, Larry

    1985-01-01

    Physicians' role in team sports goes beyond the traditional Doc who attends the game for stitching and primary injury management. Injury and illness prevention, ongoing supervision of rehabilitation, education, fitness evaluation, and training prescription are roles which have often fallen, by default, to paramedicals. The author recounts his experience in medical supervision of major junior hockey in the Western Hockey League. PMID:21274088

  8. Score a Facilities Hat Trick: Strategic Goals for Successful Hiring, Training, and Team Commitment

    ERIC Educational Resources Information Center

    Loy, Darcy

    2012-01-01

    Granted, it might be a bit of a stretch to find comparable attributes between an ice hockey team and facilities management organizations. However, if you are open-minded to the possibility and begin to analyze each of these entities, you will find there are some distinct similarities. Ice hockey is a fast-paced and ever-changing game, much like a…

  9. Insensitive fuze train for high explosives

    DOEpatents

    Cutting, J.L.; Lee, R.S.; Von Holle, W.G.

    1994-01-04

    A generic insensitive fuze train to initiate insensitive high explosives, such as PBXW-124 is described. The insensitive fuze train uses a slapper foil to initiate sub-gram quantities of an explosive, such as HNS-IV or PETN. This small amount of explosive drives a larger metal slapper onto a booster charge of an insensitive explosive, such as UF-TATB. The booster charge initiates a larger charge of an explosive, such as LX-17, which in turn, initiates the insensitive high explosive, such as PBXW-124. 3 figures.

  10. Kinetic effects in shock compressed TATB-based explosives to over 100 GPa

    NASA Astrophysics Data System (ADS)

    Holmes, N. C.; Viecelli, J. A.; Ree, F. H.; Hare, David E.

    1999-06-01

    We report on shock compression experiments on LX-17, a TATB-based insensitive high explosive. We measured the Hugoniot EOS using a novel optical method. In this method, we were able to measure both the first and reshock states on the same experiment using an optical streak camera to record shock transit times. Surprisingly, the effects of carbon nucleation are apparent at first shock pressures well above 100 GPa, while our lower pressure data are consistent with the previous data of Green.(L. Green, E. Lee, A. Mitchell, and C. Tarver, Proc. Eigth Symposium (International) on Detonation),NSWC MP 86-194 pp. 587--595.

  11. Isentropic Compression of High Explosives with the Z Accelerator

    SciTech Connect

    Reisman, D B; Forbes, J; Tarver, C M; Garcia, F; Hayes, D; Furnish, M

    2002-07-03

    Isentropic compression experiments (ICE) were performed on a variety of high explosives. The samples were dynamically loaded by Sandia's Z-accelerator with a ramp compression wave of 300 ns rise time and peak stress of 100-350 kbar. Sample/window interface velocities were recorded with VISAR. Experiments were performed on LX04 to obtain the stress-strain relation using a backward integration technique. Experiments were similarly performed on LX17 and the results compared to hydrodynamics calculations that used a reactive flow equation of state. Recent experiments were also conducted on single crystal HMX with the aim of detecting the phase transition believed to occur at 270 kbar.

  12. Insensitive fuze train for high explosives

    DOEpatents

    Cutting, Jack L. (Livermore, CA); Lee, Ronald S. (Livermore, CA); Von Holle, William G. (Livermore, CA)

    1994-01-01

    A generic insensitive fuze train to initiate insensitive high explosives, such as PBXW-124. The insensitive fuze train uses a slapper foil to initiate sub-gram quantities of an explosive, such as HNS-IV or PETN. This small amount of explosive drives a larger metal slapper onto a booster charge of an insensitive explosive, such as UF-TATB. The booster charge initiates a larger charge of an explosive, such as LX-17, which in turn, initiates the insensitive high explosive, such as PBXW-124.

  13. Free-Flying Magnetometer Data System

    NASA Technical Reports Server (NTRS)

    Blaes, B.; Javadi, H.; Spencer, H.

    2000-01-01

    The Free-Flying Magnetometer (FFM) is an autonomous "sensorcraft" developed at the Jet Propulsion Laboratory (JPL) for the Enstrophy sounding rocket mission. This mission was a collaborative project between the University of New Hampshire, Cornell University and JPL. The science goal of the mission was the study of current filamentation phenomena in the northern auroral region through multipoint measurements of magnetic field. The technical objective of the mission was the proof of concept of the JPL FFM design and the demonstration of an in-situ multipoint measurement technique employing many free-flying spacecraft. Four FFMs were successfully deployed from a sounding rocket launched from Poker Flats, Alaska on February 11, 1999. These hockey-puck-sized (80 mm diameter, 38 mm. height, 250 gram mass) free flyers each carry a miniature 3-axis flux-gate magnetometer that output +/- 2 V signals corresponding to a +/- 60,000 nT measurement range for each axis. The FFM uses a synchronized four-channel Sigma(Delta) Analog-to-Digital Converter (ADC) having a dynamic range of +/- 2.5V and converting at a rate of 279 samples/second/channel. Three channels are used to digitize the magnetometer signals to 17-bit (1.144 nT/bit) resolution. The fourth ADC channel is multiplexed for system monitoring of four temperature sensors and two battery voltages. The FFM also contains two sun sensors, a laser diode which emits a fan-shaped beam, a miniature S-band transmitter for direct communication to the ground station antennas, an ultra-stable Temperature Compensated Crystal Oscillator (TCXO) clock, an integrated data subsystem implemented in a Field-Programmable Gate Array (FPGA), a 4 Mbit Static Random Access Memory (SRAM) for data storage and Lithium Thionyl Chloride batteries for power. Communicating commands to the FFM prior to deployment is achieved with an infrared (IR) link. The FFM IR receiver responds to 9-bit pulse coded signals that are generated by an IR Light Emitting Diode (LED) in the payload for turning FFM power on or off and placing the FFM in a test mode or flight mode. The IR links are also used to synchronize (zero) the clocks onboard all the FFMs through a reset pulse originating from the payload GPS receiver that is issued when the FFMs are in flight mode. The FPGA based data subsystem manages continuous data collection from the four ADC channels and sun sensors, formatting and storing the data to SRAM, and controlling downlink transmission. The transmitter is powered only after a 2547 frame SRAM buffer has been filled (approx. 5 minutes of data). The data is Viterbi encoded and sent to the S-band transmitter via a First-In-First-Out (FIFO) buffer who's output is clocked at 100 bits/second. After the 26-second transmission, the transmitter is turned off to reduce noise coupling to the sensitive magnetometer. The data subsystem control consists of a master state machine that performs data flow management and is interfaced through a prioritized interrupt scheme to state machines that service the ADC, sun sensors and transmitter FIFO. Continuous data collection prevents the missing of data during transmission and provides implicit time tagging of the data acquired by the ADC because of synchronization with the TCXO clock.

  14. Towards Next Generation TATB-based Explosives by Understanding Voids and Microstructure from 10 nm to 1 cm

    SciTech Connect

    Willey, T M; Overturf, G

    2009-03-26

    TATB-based explosives have been investigated on length scales spanning several orders of magnitude, from just under 10 nm to larger than 1 cm. This has been accomplished using a combination of ultra-small angle x-ray scattering (USAXS), ultra-small angle neutron scattering (USANS), and x-ray computed tomography (XRCT). USAXS determines distributions the smallest structures including hot-spot voids from hundreds of nanometers to a few microns, USANS extends this range to about 10 microns, and two variants of XRCT cover sizes from microns to centimeters. Several examples are presented for LX-17, a triaminotrinitrobenzene based plastic bonded explosive using Kel-F 800. As an extension of previous USAXS results, in these proceedings, an alternate binder results in a more uniform microstructure for the PBX, useful towards design of next-generation TATB-based explosives. These data are an important step to understanding microstructural mechanisms that affect the mechanical properties of TATB-based explosives, and provide complete a comprehensive characterization of the structure of LX-17 from nanometers to centimeters that can be used as empirical input to computational models of detonation, and in determining the relationship between voids and microstructure to detonation properties.

  15. Comprehensive Characterization of Voids and Microstructure in TATB-based Explosives from 10 nm to 1 cm: Effects of Temperature Cycling and Compressive Creep

    SciTech Connect

    Willey, T M; Lauderbach, L; Gagliardi, F; Cunningham, B; Lorenz, K T; Lee, J I; van Buuren, T; Call, R; Landt, L; Overturf, G

    2010-02-26

    This paper outlines the characterization of voids and Microstructure in TATB-based Explosives over several orders of magnitude, from sizes on the order of 10 nm to about 1 cm. This is accomplished using ultra small angle x-ray scattering to investigate voids from a few nm to a few microns, ultra small angle neutron scattering for voids from 100 nm to 10 microns, and x-ray computed microtomography to investigate microstructure from a few microns to a few centimeters. The void distributions of LX-17 are outlined, and the microstructure of LX-17 is presented. Temperature cycling and compressive creep cause drastically different damage to the microstructure. Temperature cycling leads to a volume expansion (ratchet growth) in TATB-based explosives, and x-ray scattering techniques that are sensitive to sizes up to a few microns indicated changes to the void volume distribution that had previously accounted for most, but not all of the change in density. This paper presents the microstructural damage larger than a few microns caused by ratchet growth. Temperature cycling leads to void creation in the binder poor regions associated with the interior portion of formulated prills. Conversely, compressive creep causes characteristically different changes to microstructure; fissures form at binder-rich prill boundaries prior to mechanical failure.

  16. Probabilistic Threshold Criterion

    SciTech Connect

    Gresshoff, M; Hrousis, C A

    2010-03-09

    The Probabilistic Shock Threshold Criterion (PSTC) Project at LLNL develops phenomenological criteria for estimating safety or performance margin on high explosive (HE) initiation in the shock initiation regime, creating tools for safety assessment and design of initiation systems and HE trains in general. Until recently, there has been little foundation for probabilistic assessment of HE initiation scenarios. This work attempts to use probabilistic information that is available from both historic and ongoing tests to develop a basis for such assessment. Current PSTC approaches start with the functional form of the James Initiation Criterion as a backbone, and generalize to include varying areas of initiation and provide a probabilistic response based on test data for 1.8 g/cc (Ultrafine) 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and LX-17 (92.5% TATB, 7.5% Kel-F 800 binder). Application of the PSTC methodology is presented investigating the safety and performance of a flying plate detonator and the margin of an Ultrafine TATB booster initiating LX-17.

  17. Plutonium Immobilization Can Loading Concepts

    SciTech Connect

    Kriikku, E.; Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.; Rogers, L.; Fiscus, J.; Dyches, G.

    1998-05-01

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report discusses five can loading conceptual designs and the lists the advantages and disadvantages for each concept. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas. The can loading welder and cutter are very similar to the existing Savannah River Site (SRS) FB-Line bagless transfer welder and cutter and thus they are a low priority development item.

  18. Plutonium Immobilization Can Loading FY98 Year End Design Report

    SciTech Connect

    Kriikku, E.

    1998-11-25

    The Plutonium Immobilization Facility will immobilize plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with glass for permanent storage. This report summarizes FY98 Can Loading work completed for the Plutonium Immobilization Project and it includes summaries of reports on Can Size, Equipment Review, Preliminary Concepts, Conceptual Design, and Preliminary Specification. Plant trip reports for the Greenville Automation and Manufacturing Exposition, Rocky Flats BNFL Pu repackaging glovebox line, and vendor trips are also included.

  19. Deep drawing of uranium metal

    SciTech Connect

    Jackson, R J; Lundberg, M R

    1987-01-19

    A procedure was developed to fabricate uranium forming blanks with high ''draw-ability'' so that cup shapes could be easily and uniformly deep drawn. The overall procedure involved a posttreatment to develop optimum mechanical and structural properties in the deep-drawn cups. The fabrication sequence is casting high-purity logs, pucking cast logs, cross-rolling pucks to forming blanks, annealing and outgassing forming blanks, cold deep drawing to hemispherical shapes, and stress relieving, outgassing, and annealing deep-drawn parts to restore ductility and impart dimensional stability. The fabrication development and the resulting fabrication procedure are discussed in detail. The mechanical properties and microstructural properties are discussed.

  20. Diabetes: Dealing With Feelings

    MedlinePLUS

    ... reader, a hockey player, a music lover, a math whiz, a spelling champ? Are you a son ... The Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart. ...

  1. Congenital Heart Defects and Physical Activity

    MedlinePLUS

    ... after surgery. Intensely physical sports such as football, boxing or hockey may increase the chance for injury ... Heart Rate (Pulse) 5 Heart Attack Symptoms in Women 6 Low Blood Pressure 7 Warning Signs of ...

  2. Sports and Recreation Are a Rising Cause of Spinal Cord Injury.

    ERIC Educational Resources Information Center

    Tator, Charles H.; Edmonds, Virginia E.

    1986-01-01

    Sports and recreation rose from the third to the second leading cause of spinal injuries treated in two Toronto hospitals between 1948 and 1983. Separate surveys of diving and hockey injuries are also reported. (Author/MT)

  3. Preventing Children's Sports Injuries

    MedlinePLUS

    ... and padding. For racquet sports, field hockey, lacrosse, basketball , softball, and baseball, ask about any protective eyewear, ... or trip. Kids doing high-impact sports, like basketball and running, should do them on surfaces like ...

  4. Dealing with Sports Injuries

    MedlinePLUS

    ... in sports like gymnastics, field hockey, rowing, and basketball where the fingers, hands, and wrists are at ... MORE ON THIS TOPIC Sports Physicals Safety Tips: Basketball Safety Tips: Running Knee Injuries Sports and Exercise ...

  5. Coming of Age: Sports Fiction for YAs.

    ERIC Educational Resources Information Center

    Brown, Ron

    1982-01-01

    This annotated list of 26 citations covering sports fiction includes stories on football, basketball, wrestling, softball, hockey, volleyball, soccer, and baseball for young adults. It is arranged alphabetically by author with grade levels indicated. A brief introduction is provided. (EJS)

  6. Safety Tips: Baseball (For Parents)

    MedlinePLUS

    ... required for baseball isn't on par with football or hockey, but it is every bit as ... growth hormones aren't just illegal they're dangerous. Reviewed by: Steven Dowshen, MD Date reviewed: June ...

  7. Concussions in the NHL: A narrative review of the literature.

    PubMed

    Izraelski, Jason

    2014-12-01

    Ice hockey has been identified as a sport with a high risk for concussions. Given the health sequelae associated with the injury, a great deal of attention has been placed on its diagnosis, management and return-to-play protocols. The highest level of ice hockey in North America is played in the National Hockey League (NHL), and concussions pose a serious threat to the health of the players and the game itself. Unfortunately, the scientific literature on concussions in ice hockey is derived mostly from research conducted on youth and amateur levels of play, leaving a gap in our knowledge at the professional level. This narrative review attempts to summarize what is known about concussion incidence, mechanisms of injury and risk factors in the NHL. PMID:25550658

  8. Concussions in the NHL: A narrative review of the literature

    PubMed Central

    Izraelski, Jason

    2014-01-01

    Ice hockey has been identified as a sport with a high risk for concussions. Given the health sequelae associated with the injury, a great deal of attention has been placed on its diagnosis, management and return-to-play protocols. The highest level of ice hockey in North America is played in the National Hockey League (NHL), and concussions pose a serious threat to the health of the players and the game itself. Unfortunately, the scientific literature on concussions in ice hockey is derived mostly from research conducted on youth and amateur levels of play, leaving a gap in our knowledge at the professional level. This narrative review attempts to summarize what is known about concussion incidence, mechanisms of injury and risk factors in the NHL. PMID:25550658

  9. Pediatric Ocular Trauma

    MedlinePLUS

    ... usually occur from blunt trauma, such as a sports injury or a fall with injury to the nose ... eye and face protection is essential to prevent injuries. Sports such as hockey, baseball, racquet ball, squash, and ...

  10. Protect Your Eyes When You Exercise

    MedlinePLUS

    ... of them could be prevented with protective eyewear. Sports at moderate to high risk for eye injuries include: basketball, baseball, softball, ice hockey, tennis, soccer, volleyball, football, fishing, and golf. Studies show that protective eyewear does not hinder ...

  11. Your Eyes

    MedlinePLUS

    ... protection when playing racquetball, hockey, skiing, or other sports that could injure your eyes. Wear sunglasses. Too much light can damage your eyes and cause vision problems later in life. For instance, a lens ...

  12. Dealing with Peer Pressure

    MedlinePLUS

    ... soccer or field hockey? Other decisions involve serious moral questions, like whether to cut class, try cigarettes , ... and learn from other people in your age group. Peers can have a positive influence on each ...

  13. Eye Injuries in Sports

    MedlinePLUS

    ... these injuries can be prevented. Overall, basketball and baseball cause the most eye injuries, followed by water ... involve body contact. Some high-risk sports are baseball, basketball, hockey, football, lacrosse, tennis and other racquet ...

  14. Safety Tips: Basketball (For Parents)

    MedlinePLUS

    ... TOPIC Competitive Sports: Helping Kids Play it Cool Sports Medicine Center Sportsmanship Jumper's Knee (Patellar Tendonitis) Safety Tips: Hockey Safety Tips: Sledding Preventing Children's Sports Injuries Feeding Your Child Athlete Knee Injuries Safety ...

  15. New Names for New Games

    ERIC Educational Resources Information Center

    Foster, Jerry; and others

    1969-01-01

    A collection of the following original games, adapted from traditional sports: frisbee baseball, rollerboard hockey, bell ball, throw and go netball, boardless basketball, crosseball, flag football, french dodgeball, korfbal, german bat ball, and flag football. (AP)

  16. A Method of Recording Rotational Motion on a Conventional Air Table.

    ERIC Educational Resources Information Center

    Pereira, Neves

    1988-01-01

    Described is a microcomputer with two detection systems to enable three variables of the puck's motion to be recorded simultaneously: speed, radius of the orbit, and the ongoing time of measurement. Presented are the experimental setup, a discussion of the computer program, and results. (YP)

  17. Apparatus for Teaching Physics.

    ERIC Educational Resources Information Center

    Gottlieb, Herbert H., Ed.

    1980-01-01

    Summarizes the advantages in using the Daedalon Air Table, which supplies compressed air to the pucks instead of the table surface itself. Describes methods for constructing an electronic null detector using a Weston type galvanometer and an integrated circuit operational amplifier. Also describes a redesigned and improved sound-level meter. (CS)

  18. Physics Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles describe the use of a lever to transfer energy between pucks on a frictionless surface, a demonstration of the principle of conservation of linear momentum, the construction of an inexpensive joulemeter, the design and construction of a simple logic demonstration board using integrated circuits, mounting of Geiger-counters to…

  19. Remote Equipment Development for the Plutonium Ceramification Test Facility at LLNL

    SciTech Connect

    Peterson, K.D.

    2001-01-05

    The Plutonium Immobilization Plant will immobilize legacy nuclear materials in a ceramic material in the form of ''pucks'' and prepare it for permanent disposal. The Plutonium Ceramification Test Facility is being built at Lawrence Livermore National Laboratory to demonstrate proof-of-process with plant prototypic equipment, and will include a puck handling system to reduce operator exposure to radiation, to enhance operator safety, and to increase system throughput. Equipment has been selected and designed to meet the system requirements. The puck handling system is a custom-designed electromechanical unit that is configured to provide the required work envelope while fitting within the spatial constraints imposed by the glove box. Its work envelope is large relative to the spatial constraints in order to maximize its potential utility for non-routine operations such as recovery operations and housekeeping. A custom gripper was also designed to work within the severe spatial constraints imposed by other process equipment. A puck weighing/measuring station and a vacuum tool were also developed to meet system requirements. The equipment has undergone initial independent testing and is being installed to test its operation as part of the overall system.

  20. Shopping for Science.

    ERIC Educational Resources Information Center

    Ward, John; And Others

    1992-01-01

    Describes inexpensive science materials for doing science activities using the steps in the learning cycle: engage, explore, explain, extend, and evaluate. The hands-on activities help students construct knowledge of dissolving and filtering, chemical reactions, conductivity of metals, heat absorption, motion (frictionless puck), sound production…

  1. Plutonium Immobilization Can Loading Preliminary Specifications

    SciTech Connect

    Kriikku, E.

    1998-11-25

    This report discusses the Plutonium Immobilization can loading preliminary equipment specifications and includes a process block diagram, process description, equipment list, preliminary equipment specifications, plan and elevation sketches, and some commercial catalogs. This report identifies loading pucks into cans and backfilling cans with helium as the top priority can loading development areas.

  2. A Preponderance of Elastic Properties of Alpha Plutonium Measured Via Resonant Ultrasound Spectroscopy

    SciTech Connect

    Saleh, Tarik A.; Farrow, Adam M.; Freibert, Franz J.

    2012-06-06

    Samples of {alpha} plutonium were fabricated at the Los Alamos National Laboratory's Plutonium Facility. Cylindrical samples were machined from cast pucks. Precision immersion density and resonant ultrasound spectroscopy (RUS) measurements were completed on 27 new samples, yielding elastic moduli measurements. Mechanical tests were performed in compression yielding stress-strain curves as a function of rate, temperature and phase.

  3. Discrepant Results in a 2-D Marble Collision

    ERIC Educational Resources Information Center

    Kalajian, Peter

    2013-01-01

    Video analysis of 2-D collisions is an excellent way to investigate conservation of linear momentum. The often-desired experimental design goal is to minimize the momentum loss in order to demonstrate the conservation law. An air table with colliding pucks is an ideal medium for this experiment, but such equipment is beyond the budget of many

  4. Physics Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles describe the use of a lever to transfer energy between pucks on a frictionless surface, a demonstration of the principle of conservation of linear momentum, the construction of an inexpensive joulemeter, the design and construction of a simple logic demonstration board using integrated circuits, mounting of Geiger-counters to

  5. Discrepant Results in a 2-D Marble Collision

    ERIC Educational Resources Information Center

    Kalajian, Peter

    2013-01-01

    Video analysis of 2-D collisions is an excellent way to investigate conservation of linear momentum. The often-desired experimental design goal is to minimize the momentum loss in order to demonstrate the conservation law. An air table with colliding pucks is an ideal medium for this experiment, but such equipment is beyond the budget of many…

  6. Development of the Molecular Adsorber Coating for Spacecraft and Instrument Interiors

    NASA Technical Reports Server (NTRS)

    Abraham, Nithin

    2011-01-01

    On-orbit Molecular Contamination occurs when materials outgas and deposit onto very sensitive interior surfaces of the spacecraft and instruments. The current solution, Molecular Adsorber Pucks, has disadvantages, which are reviewed. A new innovative solution, Molecular Adsorber Coating (MAC), is currently being formulated, optimized, and tested. It is a sprayable alternative composed of Zeolite-based coating with adsorbing properties.

  7. 76 FR 66205 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... April 11, 2000 (65 FR 19477-78). Examining the Docket You may examine the docket that contains the... FR 35469, August 16, 1982), requires a puck-to-disc inspection of rotor brake, part number (P/N..., 1981. AD 2003-04-15, issued February 14, 2003 (68 FR 8994, February 27, 2003), requires...

  8. Techniques for Teachers Section

    ERIC Educational Resources Information Center

    Tait, A., Ed.

    1973-01-01

    Includes a simple technique to demonstrate Millikan's oil drop experiment, an environmental studies experiment to measure dissolved oxygen in water samples, and a technique to demonstrate action-reaction. Science materials described are the Pol-A-Star Tomiscope, Nuffield chemistry film loops, air pucks and pH meters. (JR)

  9. Shopping for Science.

    ERIC Educational Resources Information Center

    Ward, John; And Others

    1992-01-01

    Describes inexpensive science materials for doing science activities using the steps in the learning cycle: engage, explore, explain, extend, and evaluate. The hands-on activities help students construct knowledge of dissolving and filtering, chemical reactions, conductivity of metals, heat absorption, motion (frictionless puck), sound production

  10. Condensed and Enriched: Images of the Miniature and of the World of Children's Literature.

    ERIC Educational Resources Information Center

    Hancock, Susan

    Research into the portrayal of miniature human-like characters in the fictional narratives of art and literature suggests that profound values abound in the miniature. The paper discusses two examples of fairy miniatures, Rudyard Kipling's "Puck" and J. M. Barrie's "Tinker Bell." Little characters, whatever their provenance, can be dressed up in

  11. TARANTULA 2011 in JWL++

    SciTech Connect

    Souers, P C; Haylett, D; Vitello, P

    2011-10-27

    Using square zoning, the 2011 version of the kinetic package Tarantula matches cylinder data, cylinder dead zones, and cylinder failure with the same settings for the first time. The key is the use of maximum pressure rather than instantaneous pressure. Runs are at 40, 200 and 360 z/cm using JWL++ as the host model. The model also does run-to-detonation, thin-pulse initiation with a P-t curve and air gap crossing, all in cylindrical geometry. Two sizes of MSAD/LX-10/LX-17 snowballs work somewhat with these settings, but are too weak, so that divergent detonation is a challenge for the future. Butterfly meshes are considered but do not appear to solve the issue.

  12. Gauge Run-To Data and Failure/dead Zone Modeling

    NASA Astrophysics Data System (ADS)

    Souers, P. Clark; Vitello, Peter; Vandersall, Kevin S.

    2009-12-01

    Previous shock initiation run-to-detonation experiments on energetic materials were plotted with distance and time to get a single distance/time to detonation. Modern shots utilize enough gauges so that the distance-time data can be differentiated, which shows not only the usual inflection pressure point before detonation, referred to here as Pb, but also a second, low-pressure inflection, referred to here as Pa, that marks rapid ramp-up of the initiation. An analysis of the TATB based LX-17 and PBX 9502 in addition to the LLM-105 based RX-55 data shows that both Pa and Pb increase linearly with the initiation pressure created by the flyer plate. This contradicts the current method in the Tarantula failure/dead zone model, which uses constant pressure boundaries between reaction regions. Modeling changes required by the new data will be considered.

  13. Gauge Run-To-Detonation Data and Failure/Dead Zone Modeling

    NASA Astrophysics Data System (ADS)

    Souers, P. Clark; Vitello, Peter; Vandersall, Kevin S.

    2009-06-01

    Previous shock initiation run-to-detonation experiments on energetic materials were plotted with distance and time to get a single distance/time to detonation. Modern shots utilize enough gauges so that the distance-time data can be differentiated, which shows not only the usual inflection pressure point before detonation, referred to here as P2, but also a second, low-pressure inflection, referred to here as P1, that marks rapid ramp-up of the initiation. An analysis of the TATB based LX-17 and PBX 9502 in addition to the LLM-105 based RX-55-AB data shows that both P1 and P2 increase linearly with the initiation pressure created by the sabot. This contradicts the current method in the Tarantula failure/dead zone model, which uses constant pressure boundaries between reaction regions. Modeling changes required by the new data will be considered.

  14. Predicting the Effect of Porosity on the Shock Sensitivity of Explosives

    NASA Astrophysics Data System (ADS)

    Handley, C. A.; Lambourn, B. D.

    2009-12-01

    CREST is a reactive-burn model that uses entropy-dependent reaction rates to model shock initiation and detonation behaviour in plastic bonded explosives. A CREST model for the TATB-based high explosive PBX 9502 was published previously at this conference. It is well known that changing the porosity of an explosive, like PBX 9502, can dramatically influence its sensitivity. The equation of state used in CREST incorporates the snow-plough model, allowing the porosity of the explosive to be selected at will, while keeping the reaction model constant. In this paper, it will be shown that CREST can predict the change in explosive sensitivity with porosity, as demonstrated by the experimentally determined Pop-plots for a similar explosive, LX-17. In contrast, it will be shown that pressure-dependent reactive-burn models are unable to predict this porosity effect without changing the reaction rate.

  15. Energetic materials destruction using molten salt

    SciTech Connect

    Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.; Brummond, W.A.

    1994-04-29

    The Lawrence Livermore National Laboratory in conjunction with the Energetic Materials Center is developing methods for the safe and environmentally sound destruction of explosives and propellants as a part of the Laboratory`s ancillary demilitarization mission. LLNL has built a small-scale unit to test the destruction of HE using the Molten Salt Destruction (MSD) Process. In addition to the high explosive HMX, destruction has been carried out on RDX, PETN, ammonium picrate, TNT, nitroguanadine, and TATB. Also destroyed was a liquid gun propellant comprising hydroxyammonium nitrate, triethanolammonium nitrate and water. In addition to these pure components, destruction has been carried out on a number of commonly used formulations, such as LX-10, LX-16, LX-17, and PBX-9404.

  16. The unusual stability of TATB (1,3,5-triamino-2,4,6-trinitrobenzene): A review of the scientific literature

    SciTech Connect

    Rice, S.F.; Simpson, R.L.

    1990-07-04

    This review is intended as an up-to-date review of the scientific literature on TATB since its discovery as a high explosive. In particular, it focuses on clarifying our current understanding of the relationship between the structure of TATB and its unique thermal stability. We review a large number of different publications by many authors. A small portion of the work on TATB'' presented actually consists of experimental studies on TATB formulated as PBX-9502 or as LX-17. Where relevant, this distinction is indicated. However, inasmuch as this review focuses on thermal response and the relationship of chemical reactivity to the molecular and lattice structure of TATB as a pure material, results from these other formulations may not be directly applicable, and in general we have omitted them. 4 refs.

  17. Summary of Shock Initiation Data for TATB-based Explosives

    SciTech Connect

    Vandersall, K S

    2010-04-03

    This short summary of previously published data was compiled to provide the actual in-situ gauge data to allow modeling of these experiments. Although the purpose here is to fulfill a deliverable for a JOWOG 9 Focused Exchange (09-006), it is just as applicable to other exchanges as well. The TATB materials described here are Ultra Fine (UF) TATB and LX-17 (92.5% TATB and 7.5% Kel-F by weight), with the details of the experiments provided in the prior publications. The data is provided in the appendices of the document, but will be provided electronically as text files due to being amenable to importing into the code in that manner for comparison.

  18. GAUGE RUN-TO-DETONATION DATA AND FAILURE/DEAD ZONE MODELING

    SciTech Connect

    Souers, P C; Vitello, P; Vandersall, K S

    2009-06-26

    Previous shock initiation run-to-detonation experiments on energetic materials were plotted with distance and time to get a single distance/time to detonation. Modern shots utilize enough gauges so that the distance-time data can be differentiated, which shows not only the usual inflection pressure point before detonation, referred to here as P{sub b}, but also a second, low-pressure inflection, referred to here as P{sub a}, that marks rapid ramp-up of the initiation. An analysis of the TATB based LX-17 and PBX 9502 in addition to the LLM-105 based RX-55 data shows that both P{sub a} and P{sub b} increase linearly with the initiation pressure created by the flyer plate. This contradicts the current method in the Tarantula failure/dead zone model, which uses constant pressure boundaries between reaction regions. Modeling changes required by the new data will be considered.

  19. On the violence of thermal explosion in solid explosives

    SciTech Connect

    Chidester, S.K.; Tarver, C.M.; Green, L.G.; Urtiew, P.A.

    1997-07-01

    Heavily confined cylinders of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and triaminotrinitrobenzene (TATB) were heated at rates varying from 2 C/min to 3.3 C/h. Fourteen of the cylinders were hollow, and inner metallic liners with small heaters attached were used to produce uniform temperatures just prior to explosion. A complex thermocouple pattern was used to measure the temperature history throughout the charge and to determine the approximate location where the runaway exothermic reaction first occurred. The violence of the resulting explosion was measured using velocity pin arrays placed inside and outside of the metal confinement cylinders, flash x-rays, overpressure gauges, and fragment collection techniques. Five cylinders were intentionally detonated for violence comparisons. The measured temperature histories, times to explosion, and the locations of first reaction agreed closely with those calculated by a two-dimensional heat transfer code using multistep chemical decomposition models. The acceleration of the confining metal cylinders by the explosion process was accurately simulated using a two-dimensional pressure dependent deflagration reactive flow hydrodynamic mode. The most violent HMX thermal explosions gradually accelerated their outer cases to velocities approaching those of intentional detonations approximately 120 {micro}m after the onset of explosion. The measured inner cylinder collapse velocities from thermal explosions were considerably lower than those produced by detonations. In contrast to the HMX thermal reactions, no violent thermal explosions were produced by the TATB-based explosive LX-17. A heavily confined, slowly heated LX-17 test produced sufficient pressure to cause a 0.1 cm bend in a 2 cm thick steel plate.

  20. In-Situ Monitoring of the Microstructure of TATB-based Explosive Formulations During Temperature Cycling using Ultra-small Angle X-ray Scattering

    SciTech Connect

    Willey, T M; Hoffman, D M; van Buuren, T; Lauderbach, L; Ilavsky, J; Gee, R H; Maiti, A; Overturf, G; Fried, L

    2008-02-06

    TATB (1,3,5 triamino-2,4,6-trinitrobenzene), an extremely insensitive explosive, is used both in plastic-bonded explosives (PBXs) and as an ultra-fine pressed powder (UFTATB). With both PBXs and UFTATB, an irreversible expansion occurs with temperature cycling known as ratchet growth. In TATB-based explosives using Kel-F 800 as binder (LX-17 and PBX-9502), additional voids, sizes hundreds of nanometers to a few microns account for much of the volume expansion caused by temperature cycling. These voids are in the predicted size regime for hot-spot formation during ignition and detonation, and thus an experimental measure of these voids is important feedback for hot-spot theory and for determining the relationship between void size distributions and detonation properties. Also, understanding the mechanism of ratchet growth allows future choice of explosive/binder mixtures to minimize these types of changes to explosives, further extending PBX shelf life. This paper presents the void size distributions of LX-17, UFTATB, and PBXs using commercially available Cytop M, Cytop A, and Hyflon AD60 binders during temperature cycling between -55 C and 70 C. These void size distributions are derived from ultra-small angle x-ray scattering (USAXS), a technique sensitive to structures from about 10 nm to about 2 mm. Structures with these sizes do not appreciably change in UFTATB, indicating voids or cracks larger than a few microns appear in UFTATB during temperature cycling. Compared to Kel-F 800 binders, Cytop M and Cytop A show relatively small increases in void volume from 0.9% to 1.3% and 0.6% to 1.1%, respectively, while Hyflon fails to prevent irreversible volume expansion (1.2% to 4.6%). Computational mesoscale models of ratchet growth and binder wetting and adhesion properties point to mechanisms of ratchet growth, and are discussed in combination with the experimental results.

  1. Jack Rabbit Pretest 2021E PT7 Photonic Doppler Velocimetry Data Volume 7 Section 1

    SciTech Connect

    Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

    2008-06-25

    The Jack Rabbit Pretest (PT) 2021E PT7 experiment was fired on April 3, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT7, 160 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 20, 30, 35, 45, 55, 65, 75 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The PDV earliest signal extinction was 50.7 microseconds at 45 millimeters. The latest PDV signal extinction time was 65.0 microseconds at 20 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 55 millimeters and at 15.2 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1447 meters per second. At 65 millimeters the last measured velocity was 2360 meters per second. The low-to-high velocity ratio was 0.61. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 49 kilobars at 23.3 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 4.6 microseconds.

  2. Jack Rabbit Pretest 2021E PT3 Photonic Doppler Velocimetry Data Volume 3 Section 1

    SciTech Connect

    Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

    2008-06-25

    The Jack Rabbit Pretest (PT) 2021E PT3 was fired on March 12, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT3, 120 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 10, 20, 25, 30, 35, 40, 50 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 41.7 microseconds at 30 millimeters. The latest PDV signal extinction time was 65.0 microseconds at 10 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 40 millimeters at 10.9 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1636 meters per second. At 40 millimeters the last measured velocity was 2056 meters per second. The low-to-high velocity ratio was 0.80. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 64.6 kilobars at 15.7 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 2.2 microseconds.

  3. Jack Rabbit Pretest 2021E PT5 Photonic Doppler Velocimetry Data Volume 5 Section 1

    SciTech Connect

    Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

    2008-06-25

    The Jack Rabbit Pretest (PT) 2021E PT5 was fired on March 17, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT5, 160 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 20, 30, 35, 45, 55, 65, 75 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 40.0 microseconds at 45 millimeters. The latest PDV signal extinction time was 64.9 microseconds at 20 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 55 millimeters at 12.8 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1877 meters per second. At 65 millimeters the last measured velocity was 2277 meters per second. The low-to-high velocity ratio was 0.82. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 78 kilobars at 11.9 and 21.2 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 4.1 microseconds.

  4. Jack Rabbit Pretest 2021E PT4 Photonic Doppler Velocimetry Data Volume 4 Section 1

    SciTech Connect

    Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

    2008-06-25

    The Jack Rabbit Pretest (PT) 2021E PT4 was fired on March 19, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT4, 120 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 10, 20, 25, 30, 35, 40, 50 millimeters from the central axis. The experiment was shot at an ambient room temperature of 64 degrees Fahrenheit. The earliest PDV signal extinction was 44.9 microseconds at 30 millimeters. The latest PDV signal extinction time was 69.5 microseconds at 10 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 50 millimeters at 13.3 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1558 meters per second. At 40 millimeters the last measured velocity was 2019 meters per second. The low-to-high velocity ratio was 0.77. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 98.6 kilobars at 15.0 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 0.7 microseconds.

  5. Do pattern recognition skills transfer across sports? A preliminary analysis.

    PubMed

    Smeeton, Nicholas J; Ward, Paul; Williams, A Mark

    2004-02-01

    The ability to recognize patterns of play is fundamental to performance in team sports. While typically assumed to be domain-specific, pattern recognition skills may transfer from one sport to another if similarities exist in the perceptual features and their relations and/or the strategies used to encode and retrieve relevant information. A transfer paradigm was employed to compare skilled and less skilled soccer, field hockey and volleyball players' pattern recognition skills. Participants viewed structured and unstructured action sequences from each sport, half of which were randomly represented with clips not previously seen. The task was to identify previously viewed action sequences quickly and accurately. Transfer of pattern recognition skill was dependent on the participant's skill, sport practised, nature of the task and degree of structure. The skilled soccer and hockey players were quicker than the skilled volleyball players at recognizing structured soccer and hockey action sequences. Performance differences were not observed on the structured volleyball trials between the skilled soccer, field hockey and volleyball players. The skilled field hockey and soccer players were able to transfer perceptual information or strategies between their respective sports. The less skilled participants' results were less clear. Implications for domain-specific expertise, transfer and diversity across domains are discussed. PMID:14998098

  6. Discrepant Results in a 2-D Marble Collision

    NASA Astrophysics Data System (ADS)

    Kalajian, Peter

    2013-03-01

    Video analysis of 2-D collisions is an excellent way to investigate conservation of linear momentum. The often-desired experimental design goal is to minimize the momentum loss in order to demonstrate the conservation law. An air table with colliding pucks is an ideal medium for this experiment, but such equipment is beyond the budget of many schools. Substituting marbles on a table for air pucks introduces angular momentum and sliding friction so that simple video analysis will demonstrate that linear momentum is not conserved.1,2 Nevertheless, these labs offer students insights into the real-world application of physics. During a recent classroom trial, an unexpected result forced my students to think creatively and critically about what happened in the experiment.

  7. Petrographic composition and directional properties of tills on the NW surroundings of the Gda?sk Bay, Northern Poland

    NASA Astrophysics Data System (ADS)

    Wo?niak, Piotr Pawe?; Czubla, Piotr; Wysiecka, Gra?yna; Drapella, Ma?gorzata

    2009-10-01

    In this paper, the authors focus on some selected lithological properties of tills: petrographic composition of the 5-10 mm fraction, petrographic composition of the coarse fraction (>20 mm, analysed by the indicator erratics method) and the long axis orientation of clasts. As the study area the authors chose a territory located in Northern Poland on the NW surroundings of the Gda?sk Bay - between Puck and Lake ?arnowieckie. It was found that during the Last Glaciation the study region was fed mainly from the territory of Sweden, middle and south-eastern Sweden in particular. There existed, in parallel with the dominant (in the study region) NNW ice-sheet advance direction, also another, local ice-sheet advance route manifested in the east, which deposited a till bed in the neighbourhood of Puck.

  8. ARROW-PAK Macroencapsulation. Innovative Technology Summary Report

    SciTech Connect

    2002-04-01

    An ARROW-PAK is a high density polyethylene (HDPE) tube, about 21 feet long and 30 inches wide. Each ARROW-PAK can hold the equivalent of 21 55-gallon drums of mixed waste debris. Each tube is fused to HDPE endcaps using localized heating and high pressure contact. The sleeves and encaps form a tube for macroencapsulating mixed waste debris. The ARROW-PAK may achieve a mixed waste debris volume one-fourth that of the conventional macroencapsulation approach. The mixed waste debris is loaded into 55-gallon drums. Once filled a 'supercompactor' crushes the drums into 12-inch thick pucks. Three pucks can be loaded into a standard 85-gallon metal drum known as an 'overpack'. Seven overpacks fit into each ARROW-PAK.

  9. Plutonium Immobilization Canister Loading

    SciTech Connect

    Hamilton, E.L.

    1999-01-26

    This disposition of excess plutonium is determined by the Surplus Plutonium Disposition Environmental Impact Statement (SPD-EIS) being prepared by the Department of Energy. The disposition method (Known as ''can in canister'') combines cans of immobilized plutonium-ceramic disks (pucks) with vitrified high-level waste produced at the SRS Defense Waste Processing Facility (DWPF). This is intended to deter proliferation by making the plutonium unattractive for recovery or theft. The envisioned process remotely installs cans containing plutonium-ceramic pucks into storage magazines. Magazines are then remotely loaded into the DWPF canister through the canister neck with a robotic arm and locked into a storage rack inside the canister, which holds seven magazines. Finally, the canister is processed through DWPF and filled with high-level waste glass, thereby surrounding the product cans. This paper covers magazine and rack development and canister loading concepts.

  10. Granulator Selection

    SciTech Connect

    Gould, T H; Armantrout, G

    1999-08-02

    Following our detailed review of the granulation reports and additional conversations with process and development personnel, we have reached a consensus position regarding granulator selection. At this time, we recommend going forward with implementation of the tumbling granulator approach (GEMCO) based on our assessment of the tested granulation techniques using the established criteria. The basis for this selection is summarized in the following sections, followed by our recommendations for proceeding with implementation of the tumbling granulation approach. All five granulation technologies produced granulated products that can be made into acceptable sintered pucks. A possible exception is the product from the fluidized bed granulator. This material has been more difficult to press into uniform pucks without subsequent cracking of the puck during the sintering cycle for the pucks in this series of tests. This problem may be an artifact of the conditions of the particular granulation demonstration run involved, but earlier results have also been mixed. All granulators made acceptable granulated feed from the standpoint of transfer and press feeding, though the roller compactor and fluidized bed products were dustier than the rest. There was also differentiation among the granulators in the operational areas of (1) potential for process upset, (2) plant implementation and operational complexity, and (3) maintenance concerns. These considerations will be discussed further in the next section. Note that concerns also exist regarding the extension of the granulation processes to powders containing actinides. Only the method that involves tumbling and moisture addition has been tested with uranium, and in that instance, significant differences were found in the granulation behavior of the powders.

  11. Control of bimanual rhythmic movements: trading efficiency for robustness depending on the context.

    PubMed

    Ronsse, Renaud; Thonnard, Jean-Louis; Lefvre, Philippe; Sepulchre, Rodolphe

    2008-05-01

    This paper investigates how the efficiency and robustness of a skilled rhythmic task compete against each other in the control of a bimanual movement. Human subjects juggled a puck in 2D through impacts with two metallic arms, requiring rhythmic bimanual actuation. The arms kinematics were only constrained by the position, velocity and time of impacts while the rest of the trajectory did not influence the movement of the puck. In order to expose the task robustness, we manipulated the task context in two distinct manners: the task tempo was assigned at four different values (hence manipulating the time available to plan and execute each impact movement individually); and vision was withdrawn during half of the trials (hence reducing the sensory inflows). We show that when the tempo was fast, the actuation was rhythmic (no pause in the trajectory) while at slow tempo, the actuation was discrete (with pause intervals between individual movements). Moreover, the withdrawal of visual information encouraged the rhythmic behavior at the four tested tempi. The discrete versus rhythmic behavior give different answers to the efficiency/robustness trade-off: discrete movements result in energy efficient movements, while rhythmic movements impact the puck with negative acceleration, a property preserving robustness. Moreover, we report that in all conditions the impact velocity of the arms was negatively correlated with the energy of the puck. This correlation tended to stabilize the task and was influenced by vision, revealing again different control strategies. In conclusion, this task involves different modes of control that balance efficiency and robustness, depending on the context. PMID:18273610

  12. Ant-inspired sorting by robots: the importance of initial clustering.

    PubMed

    Melhuish, Chris; Sendova-Franks, Ana B; Scholes, Sam; Horsfield, Ian; Welsby, Fred

    2006-04-22

    For engineers the prospect of scalable collective robot systems is very appealing. Such systems typically adopt a decentralized approach in their control and coordination mechanism, which employs local sensing and action as well as limited communication. Under these constraints and informed by research on Temnothorax ants, two puck sorting algorithms were tested in a combination of simulation and with real robots. Both algorithms employed puck density as a cue. Only the overall local density, irrespective of puck type, was found to be required which offers the prospect for a more simple mechanism than had been previously considered. For one algorithm, this density cue was used both for picking up and dropping items and is, therefore, referred to as the 'double density' algorithm (DD). In the second algorithm, density was used as a cue only for picking up. Depositing an item was governed by the distance travelled which was specific to the type of item being carried. This was referred to as the 'single density' algorithm (SD). Unlike the DD it was found that, for the SD, the clustering of items is a necessary pre-condition for sorting. Results from ant experiments also showed that sorting is carried out in two phases: a primary clustering episode followed by a spacing phase. This strongly suggests that clustering may also be a precondition for spacing in ants. PMID:16849233

  13. Moisture Outgassing Rates from TATB-Formulations: Experiments and Kinetic Model Development

    SciTech Connect

    Glascoe, E A; Dinh, L N; Small IV, W

    2009-07-29

    Moisture outgassing rates from materials are of interest and importance to a variety of different fields. Because water can attack and accelerate decomposition, aging, or rusting of various parts, the assembly of an apparatus with 'wet' materials can shorten the lifetime of the apparatus. Outgassing of moisture from materials can be quite slow and a material that is seemingly dry at the time of assembly may slowly release water over years. This slow release of water will compromise the other constituents of the apparatus (e.g. electrical components, metals, organic materials) and shorten the lifetime of the apparatus. For apparatuses that are expensive or laborious to construct, it is especially important to understand and be able to predict the mechanisms and rates of water release from various materials. Such an understanding can support the development of accurate estimates of the apparatus's serviceable age and may allow for mitigation strategies in order to protect other parts from water. Energetic materials such as TATB based PBX-9502 (95% TATB, 5% Kel-F 800) and LX-17 (92.5% TATB and 7.5% Kel-F) pose a particularly challenging problem because they are heterogeneous materials with potentially many different sources and mechanisms of water release. Water molecules could be adsorbed into the polymeric binder matrix, trapped in occlusions within the polymer and the TATB crystals/particles, or trapped within defect sites in the TATB crystal. Finally, many studies indicate that water is a decomposition product under rapid heating conditions, at high temperatures and/or high pressure. Previous studies have measured the water release rate(s) from LX-17 or PBX-9502 prill/powder in order to establish oven drying times prior to use. These studies limited their time frame to a few days or a week of drying. Other studies have looked at the rate of water release of large pressed parts contained in sealed containers. Finally, some studies have looked at the rate of water diffusion through pressed parts, or the effects of wet vs. dry machining, or the influence of the synthesis methods in the amount of water present. There are a few different models that have been developed to predict the rate of water release from LX-17 or PBX-9502. These models are, to some extent, limited by the limitations of the experiments. Because all these experiments looked at water release over a relatively short period of time and left the samples relatively undamaged, they serve as a lower bound. In this work, we perform experiments and develop models that can serve as an upper bound on the rate and amount of water that can be released. Our experimental approach is to use temperature programmed desorption (TPD) and monitor the rate and amount of water release as a function of temperature. We analyzed our experimental data using two different kinetic analysis methods (isoconversional analysis and nth-order Arrhenius kinetic fits) and used the results to make predictions. The suitability of these kinetic analysis methods as well as the applicability of these experiments to long term aging (e.g. years) issues are discussed. Using the kinetics from our experiments, we predict the water release at temperature and timescales relevant to the existing literature. Based on our analysis and comparison with older data, the kinetic model(s) developed in this work serve as a relatively accurate (i.e. order of magnitude) method for predicting the water release under a variety of thermal histories.

  14. Questionable Supervision by Physical Educators

    ERIC Educational Resources Information Center

    Sawyer, Thomas H.; Gimbert, Tonya L.

    2013-01-01

    According to Court records, student Pedro Godoy (Godoy) filed a suit against the school district (Central Islip Union Free School District) and teacher Otis R. Scerbo (Scerbo), seeking to recover damages for personal injuries allegedly sustained by Godoy while participating in a game of floor hockey during physical education class. Scerbo (the

  15. Construct-a-Glove. Science by Design Series.

    ERIC Educational Resources Information Center

    Pulis, Lee

    This book is one of four books in the Science-by-Design Series created by TERC and funded by the National Science Foundation (NSF). It offers high school students a challenging, hands-on opportunity to compare the function and design of many types of handwear from a hockey mitt to a surgical glove, and design and test a glove to their own…

  16. Athletes, Doctors, and Lawyers with First Names Beginning with "D" Die Sooner

    ERIC Educational Resources Information Center

    Abel, Ernest L.; Kruger, Michael L.

    2010-01-01

    For many people, names have symbolic power that extends to their timing of death. This study examined the relationship between the symbolic significance of the first letters in the names of professional athletes (baseball, football, hockey, and basketball) and their longevity. A similar analysis was performed for doctors (radiologists,…

  17. Staying at the Top: Playing Position and Performance Affect Career Length in Professional Sport

    ERIC Educational Resources Information Center

    Baker, Joseph; Koz, Dan; Kungl, Ann-Marie; Fraser-Thomas, Jessica; Schorer, Jorg

    2013-01-01

    In an effort to understand the process of skill acquisition and decline, researchers have largely neglected a critical aspect of this development--maximizing time at the highest levels of achievement. This study examined length of career for professional athletes in basketball, football, ice hockey, and baseball and considers whether career length…

  18. Regressing Team Performance on Collective Efficacy: Considerations of Temporal Proximity and Concordance

    ERIC Educational Resources Information Center

    Myers, Nicholas D.; Paiement, Craig A.; Feltz, Deborah L.

    2007-01-01

    The purpose of this study was to determine to what degree collective efficacy judgments based on summative team performance capabilities exhibited different levels of prediction for three additive intervals of team performance in women's ice hockey. Collective efficacy beliefs of 12 teams were assessed prior to Friday's game and Saturday's game…

  19. Some Ways of Helping Underachievers.

    ERIC Educational Resources Information Center

    Willings, David; Greenwood, Bill

    1990-01-01

    A program of intervention called therapeutic tutoring to help underachievers is described. Intervention centers around students' loci of control, through a process of identifying areas in which students feel empowered and relating academic experiences to these areas. Academic exercises based on Monopoly, cricket, rugby, soap operas, field hockey,

  20. The Lived Experience of a Doctoral Student: The Process of Learning and Becoming

    ERIC Educational Resources Information Center

    Callary, Betina; Werthner, Penny; Trudel, Pierre

    2012-01-01

    The PhD experience is often a transition from student to future faculty member, which involves considerable learning and development (Glaze, 2002; Hockey, 2004). Using a lifelong learning perspective (Jarvis, 2009), the purpose of this article is to explore, through a reflective self-study, my process of learning throughout the PhD degree. In this

  1. Girls Physical Education Handbook.

    ERIC Educational Resources Information Center

    Fairfax County Schools, VA.

    This handbook was designed to provide the student with basic information for various individual, dual, and team sports. The individual and dual sports which are discussed include archery, badminton, creative dance, fencing, golf, gymnastics, and games such as deck tennis, table tennis, horseshoes, and shuffledboard. Basketball, field hockey,…

  2. 1997 Arthur Ashe Jr. Sport Scholars Awards.

    ERIC Educational Resources Information Center

    Roach, Ronald

    1997-01-01

    Winners of the "Black Issues in Higher Education" Arthur Ashe Jr. 1997 athletes of the year, one male and one female, are profiled and Sport Scholars are listed for baseball, softball, basketball, fencing, archery, football, handball, soccer, field hockey, crew, swimming, gymnastics, tennis, squash, golf, volleyball, lacrosse, wrestling, water

  3. A Case Study of Wikis and Student-Designed Games in Physical Education

    ERIC Educational Resources Information Center

    Hastie, Peter A.; Casey, Ashley; Tarter, Anne-Marie

    2010-01-01

    This paper reports on the incorporation of wiki technology within physical education. Boys from two classes at a school in the United Kingdom were divided into small teams and given the task of creating a new game in a same genre as football, hockey, netball or rugby. Each team had a wiki on which were recorded all the plans and developments of

  4. Sports Involvement and Academic Achievement: A Study of Malaysian University Athletes

    ERIC Educational Resources Information Center

    Chuan, Chun Cheng; Yusof, Aminuddin; Shah, Parilah Mohd

    2013-01-01

    Factors that influence the academic achievement of Malaysian university athletes were investigated using 156 field hockey players from several universities. The relationship between team subculture, parental influence, the learning environment, support systems, financial aid, training factors, academic assistance, socialization, and stress level…

  5. Regressing Team Performance on Collective Efficacy: Considerations of Temporal Proximity and Concordance

    ERIC Educational Resources Information Center

    Myers, Nicholas D.; Paiement, Craig A.; Feltz, Deborah L.

    2007-01-01

    The purpose of this study was to determine to what degree collective efficacy judgments based on summative team performance capabilities exhibited different levels of prediction for three additive intervals of team performance in women's ice hockey. Collective efficacy beliefs of 12 teams were assessed prior to Friday's game and Saturday's game

  6. Myth 11: A Comprehensive Continuum of Gifted Education and Talent Development Services--Discovering, Developing, and Enhancing Young People's Gifts and Talents

    ERIC Educational Resources Information Center

    Gentry, Marcia

    2009-01-01

    To determine whether having a program is sufficient one must first define what is meant by "program." If by program one refers to the pullout program in the elementary school, or the afterschool enrichment program in the middle school, or the Advanced Placement program in the high school, or the hockey program, then certainly having a "program" is

  7. Sports for Life

    ERIC Educational Resources Information Center

    Schachter, Ron

    2010-01-01

    When Saul Lerner became director of physical education, athletics, and health for the Bellmore-Merrick (New York) School District 14 years ago, football, soccer, basketball, and floor hockey were staples of most physical education classes on Long Island and around the rest of the country. The mindset of physical educators was to emphasize sports…

  8. The Analysis of the Thinking Styles and Creativity of the Sports Students Studying in the Different Fields of University

    ERIC Educational Resources Information Center

    Eraslan, Meric

    2014-01-01

    This study analyzes the creativity and thinking levels of athletes studying at the different college departments; 61 female and 75 male athletes, a total of 136 ice-hockey players have participated in the research. As data collection tools, Thinking Styles Inventory and The Creativity Scale have been used in the study. SPSS 15.0 for Windows…

  9. 1998 Arthur Ashe Jr. Sports Scholars Awards.

    ERIC Educational Resources Information Center

    Chenoweth, Karin; Evelyn, Jamilah

    1998-01-01

    Announces the Sports Scholars Awards for 1998. One male and one female college athlete are profiled, and others are named for baseball, softball, basketball, fencing, riflery, bowling, football, wrestling, soccer, lacrosse, field hockey, swimming/diving, gymnastics, crew, tennis, golf, volleyball, track/field, cross country, downhill skiing, and…

  10. Factors affecting the relative age effect in NHL athletes

    PubMed Central

    Parent-Harvey, Caroline I.; Desjardins, Christophe; Harvey, Edward J.

    2014-01-01

    Background The relative age effect (RAE) has been reported for a number of different activities. The RAE is the phenomena whereby players born in the first few months of a competition year are advantaged for selection to elite sports. Much of the literature has identified elite male athletics, such as the National Hockey League (NHL), as having consistently large RAEs. We propose that RAE may be lessened in the NHL since the last examination. Methods We examined demographic and selection factors to understand current NHL selection biases. Results We found that RAE was weak and was only evident when birth dates were broken into year halves. Players born in the first half of the year were relatively advantaged for entry into the NHL. We found that the RAE is smaller than reported in previous studies. Intraplayer comparisons for multiple factors, including place of birth, country of play, type of hockey played, height and weight, revealed no differences. Players who were not drafted (e.g., free agents) or who played university hockey in North America had no apparent RAE. Conclusion We found little evidence of an RAE in the current NHL player rosters. A larger study of all Canadian minor hockey intercity teams could help determine the existence of an RAE. PMID:24869606

  11. Modifying Intramural Rules.

    ERIC Educational Resources Information Center

    Rokosz, Francis M.

    1981-01-01

    Standard sports rules can be altered to improve the game for intramural participants. These changes may improve players' attitudes, simplify rules for officials, and add safety features to a game. Specific rule modifications are given for volleyball, football, softball, floor hockey, basketball, and soccer. (JN)

  12. 1997 Arthur Ashe Jr. Sport Scholars Awards.

    ERIC Educational Resources Information Center

    Roach, Ronald

    1997-01-01

    Winners of the "Black Issues in Higher Education" Arthur Ashe Jr. 1997 athletes of the year, one male and one female, are profiled and Sport Scholars are listed for baseball, softball, basketball, fencing, archery, football, handball, soccer, field hockey, crew, swimming, gymnastics, tennis, squash, golf, volleyball, lacrosse, wrestling, water…

  13. Beyond Women's Collegiate Athletics. Opportunities to Play for Pay.

    ERIC Educational Resources Information Center

    Lehr, Carolyn A.; Washington, Martha A.

    1987-01-01

    Despite the increased emphasis on women's sports and rising participation rates, women are still severely limited in careers as competitors or in sports-related occupations. Opportunities in basketball, volleyball, tennis, cross-country and track, softball, golf, soccer and field hockey, aquatic sports, and a few other sports are examined. (MT)

  14. The National Association for Girls and Women in Sport: 110 Years of Promoting Social Justice and Change

    ERIC Educational Resources Information Center

    Ladda, Shawn

    2009-01-01

    From writing the first Guidebooks for hockey, soccer, swimming, track and field, and basketball, to lobbying Congress to strive for equity and equal opportunities for girls, the National Association for Girls and Women in Sport (NAGWS) has been and continues to be the beacon in education to advance fairness and equity in sports. As NAGWS enters

  15. Alpine Skiing in the Classroom

    ERIC Educational Resources Information Center

    Mendez-Gimenez, Antonio; Fernandez-Rio, Javier

    2012-01-01

    Many students settle indoors in the winter. However, this does not mean that winter should be a period of time with no physical activity. Several snow activities could be practiced during those months, such as ice-skating, ice-hockey, snowshoeing, cross-country skiing, alpine skiing, or snowboarding. In order to counteract the tendency for

  16. The Role of Personal Experience in the Neural Processing of Action-Related Language

    ERIC Educational Resources Information Center

    Lyons, Ian M.; Mattarella-Micke, Andrew; Cieslak, Matthew; Nusbaum, Howard C.; Small, Steven L.; Beilock, Sian L.

    2010-01-01

    We investigated how auditory language processing is modified by a listener's previous experience with the specific activities mentioned in the speech. In particular, we asked whether neural responses related to language processing depend on one's experience with the action-based content of this language. Ice-hockey players and novices passively

  17. Are Children's Competitive Team Sports Socializing Agents for Corporate America?

    ERIC Educational Resources Information Center

    Berlage, Gai Ingham

    In a study of the similarities between childrens' competitive team sports and the typical corporate or business environment, two research questions were posed: (1) Does the structural organization of childrens' soccer and ice hockey organizations resemble that of American corporations?; and (2) Are the values of childrens' competitive sports

  18. Five Year Overview of Sport Injuries: The NAIRS Model.

    ERIC Educational Resources Information Center

    Buckley, William E.

    1982-01-01

    Data from a survey of institutional members of the National Athletic Injury/Illness Reporting System (NAIRS) are presented and discussed. Included are tables showing injuries reported in high schools and colleges and universities for male and female athletes in baseball, basketball, football, gymnastics, soccer, wrestling, field hockey, track and…

  19. A Group Vocational Project for LD Students

    ERIC Educational Resources Information Center

    Kosmakos, Maria; Decker, Lawrence A.

    1977-01-01

    Designing and building a hockey table offered upper school students at Ashbourne School in Elkins Park, Pennsylvania, vocational and academic instruction, opportunities to channel aggressive and sexual impulses, experiences that enhanced self-image, healthy peer relationships, and opportunities for individual initiative and involvement. (JG)

  20. Speed-A-Way, Physical Education: 5551.14.

    ERIC Educational Resources Information Center

    King, Katheryn

    This course outline is a guide (grades 7-12) for teaching speed-a-way, a game combining soccer, basketball, speedball, and field hockey skills. The course format includes discussions, demonstrations, skills practice, films, and tests that focus on mastery of skills, understanding of rules and officiating, testing skill performance and rules

  1. Fit by Five.

    ERIC Educational Resources Information Center

    Wells, Maureen

    1978-01-01

    Describes a preschool program in which all skills, including academic and social skills, are taught through movement. Children are introduced to over 300 physical activities and sports in a year's time including: balance beam, parallel bars, trampoline, swimming, hockey, basketball, golf, archery, track, and volleyball. (JMB)

  2. Athletes, Doctors, and Lawyers with First Names Beginning with "D" Die Sooner

    ERIC Educational Resources Information Center

    Abel, Ernest L.; Kruger, Michael L.

    2010-01-01

    For many people, names have symbolic power that extends to their timing of death. This study examined the relationship between the symbolic significance of the first letters in the names of professional athletes (baseball, football, hockey, and basketball) and their longevity. A similar analysis was performed for doctors (radiologists,

  3. A Case Study Objectively Assessing Female Physical Activity Levels within the National Curriculum for Physical Education

    ERIC Educational Resources Information Center

    Hobbs, Matthew; Daly-Smith, Andrew; Morley, David; McKenna, James

    2015-01-01

    The purpose of this study was to assess the impact of the National Curriculum for Physical Education (NCPE) lesson themes and contexts on the profile of moderate-to-vigorous physical activity (MVPA). Fifteen, Year 9 Physical Education (PE) lessons were assessed within the lesson themes of Outwitting Opponents (OO) (delivered through field hockey

  4. Comparative Evaluation of Two Serial Gene Expression Experiments | Division of Cancer Prevention

    Cancer.gov

    Stuart G. Baker, 2014 Introduction This program fits biologically relevant response curves in comparative analysis of the two gene expression experiments involving same genes but under different scenarios and at least 12 responses. The program outputs gene pairs with biologically relevant response curve shapes including flat, linear, sigmoid, hockey stick, impulse and step curves. |

  5. Pupils' Perceptions of and Experiences in Team Invasion Games: A Case Study of a Scottish Secondary School and Its Three Feeder Primary Schools

    ERIC Educational Resources Information Center

    Gray, Shirley; Sproule, John; Wang, C. K. John

    2008-01-01

    It has been claimed that young children in schools in Scotland cannot relate to the activities that are taught in the more "traditional" PE curriculum, activities that predominately include team invasion games (TIG) such as basketball, soccer and hockey (Scottish Executive, 2004). However, one of the issues with this claim is that it does not…

  6. Living with Marfan Syndrome

    MedlinePLUS

    ... hard ball. Examples of these sports are baseball, soccer, and ice hockey. Your doctor may suggest low- and moderate-impact activities, such as swimming, golf, brisk walking, hiking, and tennis. If you have a child who has Marfan syndrome, talk with his or ...

  7. Are Children's Competitive Team Sports Socializing Agents for Corporate America?

    ERIC Educational Resources Information Center

    Berlage, Gai Ingham

    In a study of the similarities between childrens' competitive team sports and the typical corporate or business environment, two research questions were posed: (1) Does the structural organization of childrens' soccer and ice hockey organizations resemble that of American corporations?; and (2) Are the values of childrens' competitive sports…

  8. Leadership Development of Team Captains in Collegiate Varsity Athletics

    ERIC Educational Resources Information Center

    Grandzol, Christian; Perlis, Susan; Draina, Lois

    2010-01-01

    This study examined the leadership development of team captains and student-athletes engaged in NCAA Division III intercollegiate athletics at 6 private institutions of higher education. Student-athletes in the sports of men's and women's soccer, women's field hockey, men's and women's cross country, and women's tennis completed the 2nd edition of

  9. Social Cognitive Correlates of Young Adult Sport Competitors' Sunscreen Use

    ERIC Educational Resources Information Center

    Berndt, Nadine C.; O'Riordan, David L.; Winkler, Elisabeth; McDermott, Liane; Spathonis, Kym; Owen, Neville

    2011-01-01

    Young adults participating in outdoor sports represent a high-risk group for excessive sun exposure. The purpose of this study was to identify modifiable social cognitive correlates of sunscreen use among young adult competitors. Participants aged 18 to 30 years who competed in soccer (n = 65), surf-lifesaving (n = 63), hockey (n = 61), and tennis

  10. Studies of Television and Youth Sports: Laboratory/Field Research on the Effects of Pro-Social and Anti-Social TV Models on Children/Youth in Sport/Athletics.

    ERIC Educational Resources Information Center

    Moriarty, Dick; And Others

    This study investigates the question of whether or not exposure to televised professional sports affects the social behavior of young people who themselves actively engage in those sports. Lacrosse, hockey, baseball were monitored on television, with students questioned about the impact the behavior of the players (pro-social and anti-social) has

  11. Diabetes: Dealing With Feelings

    MedlinePLUS

    ... get lost in all the negative ways diabetes affects your world. If you feel like it's taking over your life, it can help to write down your strengths — and the stuff you love. Who are you? Are you a reader, a hockey player, a music lover, a math whiz, a spelling champ? Are ...

  12. Biography Today: Sports Series. Profiles of People of Interest to Young Readers. Volume 3, 1999.

    ERIC Educational Resources Information Center

    Harris, Laurie Lanzen, Ed.; Abbey, Cherie D., Ed.

    This third volume is part of a series of biographies that profile individuals of interest to young people over the age of 9 years. The entries in this volume include Joe Dumars, basketball; Jim Harbaugh, football; Dominik Hasek, hockey; Michelle Kwan, figure skating; Rebecca Lobo, basketball; Greg Maddux, baseball; Fatuma Roba, marathon running;

  13. Practical Applications of the Compound Pendulum.

    ERIC Educational Resources Information Center

    Hinrichsen, Peter F.

    1981-01-01

    Examples of the application of compound pendulum theory to the practical measurement of the moments of inertia of human beings, farm tractors, and sailing boats are presented. Suggests developing laboratory experiments to measure moments of inertia of hockey sticks, golf clubs, and frisbees, among others. (Author/SK)

  14. A Pirate's Life: A Model and a Metaphor for Learning.

    ERIC Educational Resources Information Center

    Solomon, David L.

    2002-01-01

    Discusses various ways in which context may be interpreted to enhance learning and performance; illustrates domains of learning using a hockey team as an example; and suggests implications for learning, performance, and instructional design. Highlights include an ecological systems model; and examples of individual development, team learning, and

  15. Sport in Canada During the Depression.

    ERIC Educational Resources Information Center

    Lappage, Ronald S.

    The author discusses the effect of the Great Depression upon sport in Canada. The difficulties of hockey and football teams are contrasted with the success of professional wrestling, horseracing, and bicycling. The economic plight of professional players who were not allowed to return to the "amateur" rank is discussed. Increased participation in

  16. "Emerging" Sports for Women.

    ERIC Educational Resources Information Center

    Blum, Debra E.

    1994-01-01

    The National Collegiate Athletic Association has recently introduced nine new sports to intercollegiate athletics: team handball, archery, badminton, bowling, crew, ice hockey, squash, synchronized swimming, and water polo. The initiative is intended to encourage colleges to create more athletic opportunities for women. It sets scholarship limits

  17. Staying at the Top: Playing Position and Performance Affect Career Length in Professional Sport

    ERIC Educational Resources Information Center

    Baker, Joseph; Koz, Dan; Kungl, Ann-Marie; Fraser-Thomas, Jessica; Schorer, Jorg

    2013-01-01

    In an effort to understand the process of skill acquisition and decline, researchers have largely neglected a critical aspect of this development--maximizing time at the highest levels of achievement. This study examined length of career for professional athletes in basketball, football, ice hockey, and baseball and considers whether career length

  18. A Survey to Determine to What Extent Ohlone College Is Meeting the Needs of Student Athletes.

    ERIC Educational Resources Information Center

    Baker, John

    A questionnaire was administered to all 1978 fall quarter student athletes at Ohlone College (California) to assess their goals and needs, and to find out to what degree student experience matched expectation. There was an 86% (N=85) response rate from the varsity men and women teams (volleyball, field hockey, soccer, water polo, and football).

  19. Mathematics and Sports. Mathematical World. Volume 3.

    ERIC Educational Resources Information Center

    Sadovskii, L. E.; Sadovskii, A. L.

    This volume contains some examples of mathematical applications in sports. Sports discussed include tennis, figure skating, gymnastics, track and field, soccer, skiing, hockey, and swimming. Problems and situations are posed and answers with thorough explanations are provided. Chapters include: (1) Mathematics and Sports; (2) What Is Applied…

  20. Sports for Life

    ERIC Educational Resources Information Center

    Schachter, Ron

    2010-01-01

    When Saul Lerner became director of physical education, athletics, and health for the Bellmore-Merrick (New York) School District 14 years ago, football, soccer, basketball, and floor hockey were staples of most physical education classes on Long Island and around the rest of the country. The mindset of physical educators was to emphasize sports

  1. Social Cognitive Correlates of Young Adult Sport Competitors' Sunscreen Use

    ERIC Educational Resources Information Center

    Berndt, Nadine C.; O'Riordan, David L.; Winkler, Elisabeth; McDermott, Liane; Spathonis, Kym; Owen, Neville

    2011-01-01

    Young adults participating in outdoor sports represent a high-risk group for excessive sun exposure. The purpose of this study was to identify modifiable social cognitive correlates of sunscreen use among young adult competitors. Participants aged 18 to 30 years who competed in soccer (n = 65), surf-lifesaving (n = 63), hockey (n = 61), and tennis…

  2. Leadership Development of Team Captains in Collegiate Varsity Athletics

    ERIC Educational Resources Information Center

    Grandzol, Christian; Perlis, Susan; Draina, Lois

    2010-01-01

    This study examined the leadership development of team captains and student-athletes engaged in NCAA Division III intercollegiate athletics at 6 private institutions of higher education. Student-athletes in the sports of men's and women's soccer, women's field hockey, men's and women's cross country, and women's tennis completed the 2nd edition of…

  3. Alpine Skiing in the Classroom

    ERIC Educational Resources Information Center

    Mendez-Gimenez, Antonio; Fernandez-Rio, Javier

    2012-01-01

    Many students settle indoors in the winter. However, this does not mean that winter should be a period of time with no physical activity. Several snow activities could be practiced during those months, such as ice-skating, ice-hockey, snowshoeing, cross-country skiing, alpine skiing, or snowboarding. In order to counteract the tendency for…

  4. The National Association for Girls and Women in Sport: 110 Years of Promoting Social Justice and Change

    ERIC Educational Resources Information Center

    Ladda, Shawn

    2009-01-01

    From writing the first Guidebooks for hockey, soccer, swimming, track and field, and basketball, to lobbying Congress to strive for equity and equal opportunities for girls, the National Association for Girls and Women in Sport (NAGWS) has been and continues to be the beacon in education to advance fairness and equity in sports. As NAGWS enters…

  5. A Laboratory/Field Study of Television Violence and Aggression in Children's Sports.

    ERIC Educational Resources Information Center

    McCabe, Ann E.; Moriarty, Richard J.

    A study on the effect of viewing violence on television on childrens' behavior was conducted within the context of sport activity. Three sports--baseball, hockey, and lacrosse--were chosen. Teams of children from three different age groups were the subjects. Within each of the age levels in each sport, teams were selected and assigned to

  6. Five Year Overview of Sport Injuries: The NAIRS Model.

    ERIC Educational Resources Information Center

    Buckley, William E.

    1982-01-01

    Data from a survey of institutional members of the National Athletic Injury/Illness Reporting System (NAIRS) are presented and discussed. Included are tables showing injuries reported in high schools and colleges and universities for male and female athletes in baseball, basketball, football, gymnastics, soccer, wrestling, field hockey, track and

  7. Plyometrics: A Legitimate Form of Power Training?

    ERIC Educational Resources Information Center

    Duda, Marty

    1988-01-01

    Plyometric exercises or drills combine speed and strength to produce an explosive-reactive movement or increased power. Some world-class athletes have used plyometric-training in sports such as high-jumping, hurdles, football, baseball, and hockey. The method is still considered experimental. Sample exercises are described. (JL)

  8. Comparative Evaluation of Two Serial Gene Expression Experiments | Division of Cancer Prevention

    Cancer.gov

    Stuart G. Baker, 2014 Introduction This program fits biologically relevant response curves in comparative analysis of the two gene expression experiments involving same genes but under different scenarios and at least 12 responses. The program outputs gene pairs with biologically relevant response curve shapes including flat, linear, sigmoid, hockey stick, impulse and step curves.

  9. An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

    NASA Technical Reports Server (NTRS)

    Cosgriff, Laura M.; Roberts, Gary D.; Binienda, Wieslaw K.; Zheng, Diahua; Averbeck, Timothy; Roth, Donald J.; Jeanneau, Philippe

    2006-01-01

    Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

  10. Some Ways of Helping Underachievers.

    ERIC Educational Resources Information Center

    Willings, David; Greenwood, Bill

    1990-01-01

    A program of intervention called therapeutic tutoring to help underachievers is described. Intervention centers around students' loci of control, through a process of identifying areas in which students feel empowered and relating academic experiences to these areas. Academic exercises based on Monopoly, cricket, rugby, soap operas, field hockey,…

  11. A Case Study of Wikis and Student-Designed Games in Physical Education

    ERIC Educational Resources Information Center

    Hastie, Peter A.; Casey, Ashley; Tarter, Anne-Marie

    2010-01-01

    This paper reports on the incorporation of wiki technology within physical education. Boys from two classes at a school in the United Kingdom were divided into small teams and given the task of creating a new game in a same genre as football, hockey, netball or rugby. Each team had a wiki on which were recorded all the plans and developments of…

  12. The Analysis of the Thinking Styles and Creativity of the Sports Students Studying in the Different Fields of University

    ERIC Educational Resources Information Center

    Eraslan, Meric

    2014-01-01

    This study analyzes the creativity and thinking levels of athletes studying at the different college departments; 61 female and 75 male athletes, a total of 136 ice-hockey players have participated in the research. As data collection tools, Thinking Styles Inventory and The Creativity Scale have been used in the study. SPSS 15.0 for Windows

  13. The Pasternak Case and American Gender Equity Policy: Implications for Canadian High School Athletics

    ERIC Educational Resources Information Center

    Beaubier, Dean M.; Gadbois, Shannon A.; Stick, Sheldon L.

    2011-01-01

    In 2004 twin sisters Amy and Jesse Pasternak competed for the prospect of playing high school hockey, vying for the boys' team rather than the girls'. The sisters' opportunities were negated by the Manitoba High School Athletic Association (MHSAA). This paper examines the 2006 decision by the Manitoba Human Rights Commission and a 2008 judgment by

  14. Lunar Influences on Human Aggression.

    ERIC Educational Resources Information Center

    Russell, Gordon W.; Dua, Manjula

    1983-01-01

    Used league records of all Canadian hockey games (N=426) played during a season to test a lunar-aggression hypothesis. Despite the use of multiple measures of lunar phase and interpersonal aggression, support for lunar influence was not forthcoming. Supplemental data revealed that beliefs in lunar influence are fairly common. (JAC)

  15. The Effects of Teaching Styles on Motor Performance, Self Concept, and Social Skill Development.

    ERIC Educational Resources Information Center

    Goldberger, Michael

    The effects of three teaching styles in Mosston's Spectrum of Teaching Styles were examined in terms of the motor skill acquisition and social skill development of 96 randomly selected fifth grade students, who were taught a hockey accuracy task. Performance data were collected prior to, midway through, and following training and were analyzed:

  16. Internet-Accessible Scholarly Resources for the Humanities and Social Sciences.

    ERIC Educational Resources Information Center

    ACLS Newsletter, 1997

    1997-01-01

    This newsletter focuses on the presentations of a program session on Internet-accessible scholarly resources, held at the 1996 ACLS Annual Meeting. Articles in the newsletter include: "Building the Scene: Words, Images, Data, and Beyond" (David Green); "Electronic Texts: The Promise and the Reality" (Susan Hockey); "Images on the Internet: Issues

  17. 1998 Arthur Ashe Jr. Sports Scholars Awards.

    ERIC Educational Resources Information Center

    Chenoweth, Karin; Evelyn, Jamilah

    1998-01-01

    Announces the Sports Scholars Awards for 1998. One male and one female college athlete are profiled, and others are named for baseball, softball, basketball, fencing, riflery, bowling, football, wrestling, soccer, lacrosse, field hockey, swimming/diving, gymnastics, crew, tennis, golf, volleyball, track/field, cross country, downhill skiing, and

  18. The Development of Ojibway Language Materials.

    ERIC Educational Resources Information Center

    Pheasant-Williams, Shirley

    2003-01-01

    Revitalization of the Nishinaabeg language started in 1998 with the development of language materials. A committee on Nishinaabemwin orthography advised on the development of the text and writing system. Teaching methods follow the four parts of Medicine Wheel teachings: spiritual, emotional, physical, and mental. An interactive hockey game and a

  19. Shock-wave initiation of heated plastified TATB detonation

    NASA Astrophysics Data System (ADS)

    Kuzmitsky, Igor; Rudenko, Vladimir; Gatilov, Leonid; Koshelev, Alexandr

    1999-06-01

    Explosive, plastified TATB, attracts attention with its weak sensitivity to shock loads and high temperature stability ( Pthreshold ? 6.5 GPa and Tcrit ? 250 0Q). However, at its cooling to T 250 0Q plastified TATB becomes as sensitive to shock load as octogen base HE: the excitation threshold reduces down to Pthreshold 2.0 GPa. The main physical reason for the HE sensitivity change is reduction in density at heating and, hence, higher porosity of the product (approximately from 2Moreover, increasing temperature increases the growth rate of uhotf spots which additionally increases the shock sensitivity [1]. Heated TATB experiments are also conducted at VNIIEF. The detonation excitation was computed within 1D program system MAG using EOS JWL for HE and EP and LLNL kinetics [1,2,3]. Early successful results of using this kinetics to predict detonation excitation in heated plastified TATB in VNIIEF experiments with short and long loading pulses are presented. Parameters of the chemical zone of the stationary detonation wave in plastified TATB (LX-17) were computed with the data from [1]. Parameters Heated In shell Cooled Unheated ?0 , g/cm3 1.70 1.81 1.84 1.905 D , km/s 7.982 7.764 7.686 7.517 PN, GPa 45.4 45.8 35.7 32.9 PJ, GPa 27.0 27.3 27.2 26.4 ?x , mm 0.504 0.843 1.041 2.912 ?t , ns 63.1 108.6 135.5 387.4 [1] Effect of Confinement and Thermal Cycling on the Shock Initiation of LX-17 P.A. Urtiew, C.M. Tarver, J.L. Maienschein, and W.C. Tao. LLNL. Combustion and Flame 105: 43-53 (1996) [2] C.M. Tarver, P.A. Urtiew and W.C. Tao (LLNL) Effects of tandem and colliding shock waves on initiation of triaminotrinitrobenzene. J.Appl. Phys. 78(5), September 1995 [3] Craig M. Tarver, John W. Kury and R. Don Breithaupt Detonation waves in triaminotrinitrobenzene J. Appl. Phys. 82(8) , 15 October 1997.

  20. Skating crossovers on a motorized flywheel: a preliminary experimental design to test effect on speed and on crossovers.

    PubMed

    Smith, Aynsley M; Krause, David A; Stuart, Michael J; Montelpare, William J; Sorenson, Matthew C; Link, Andrew A; Gaz, Daniel V; Twardowski, Casey P; Larson, Dirk R; Stuart, Michael B

    2013-12-01

    Ice hockey requires frequent skater crossovers to execute turns. Our investigation aimed to determine the effectiveness of training crossovers on a motorized, polyethylene high-resistance flywheel. We hypothesized that high school hockey players training on the flywheel would perform as well as their peers training on ice. Participants were 23 male high-school hockey players (age 15-19 years). The study used an experimental prospective design to compare players who trained for 9 sessions on the 22-foot flywheel with players who trained for 9 sessions on a similarly sized on-ice circle. Both groups were compared with control subjects who were randomly selected from the same participant pool as those training on ice. All players were tested before and after their 3-week training regimens, and control subjects were asked to not practice crossovers between testing. Group 1 trained in a hockey training facility housing the flywheel, and group 2 trained in the ice hockey arena where testing occurred. Primary outcome measures tested in both directions were: (a) speed (time in seconds) required to skate crossovers for 3 laps of a marked face-off circle, (b) cadence of skating crossovers on the similarly sized circles, and (c) a repeat interval speed test, which measures anaerobic power. No significant changes were found between groups in on-ice testing before and after training. Among the group 1 players, 7 of 8 believed they benefited from flywheel training. Group 2 players, who trained on ice, did not improve performance significantly over group 1 players. Despite the fact that no significant on-ice changes in performance were observed in objective measures, players who trained on the flywheel subjectively reported that the flywheel is an effective cost-effective alternative to training on ice. This is a relevant finding when placed in context with limited availability of on-ice training. PMID:23539081

  1. Creep Testing Plastic-Bonded Explosives in Uni-axial Compression

    SciTech Connect

    Gagliardi, F J; Cunningham, B J

    2008-03-13

    High fidelity measurements of time-dependent strain in the plastic-bonded explosives LX-17-1 and PBX 9502 have been performed under constant, uni-axial, compressive load using a custom designed apparatus. The apparatus uses a combination of extensometers and linear variable differential transformers coupled with a data acquisition system, thermal controls, and gravitational loading. The materials being tested consist of a crystalline explosive material mixed with a polymeric binder. The behavior of each material is related to the type of explosive and to the percentage and type of binder. For any given plastic-bonded explosive, the creep behavior is also dependent on the stress level and test temperature. Experiments were conducted using a 3 x 3 stress-temperature matrix with a temperature range of 24 C to 70 C and with stresses ranging from 250-psi to 780-psi. Analysis of the data has shown that logarithmic curve fits provide an accurate means of quantification and facilitate a long-term predictive capability. This paper will discuss the design of the apparatus, experimental results, and analyses.

  2. Materials and Sensor R&D to Transform the Nuclear Stockpile: Livermore?s Transformational Materials Initiative

    SciTech Connect

    Maxwell, R; Fried, L; Campbell, G; Saab, A; Kotovsky, J; Carter, C; Chang, J

    2009-10-11

    As the nation's nuclear weapons age and the demands placed on them change, significant challenges face the nuclear stockpile. Risks include material supply issues, ever-increasing lifecycle costs, and loss of technical expertise across the weapons complex. For example, non-nuclear materials are becoming increasingly difficult to replace because manufacturing methods and formulations have evolved in such a way as to render formerly available materials unprofitable, unsafe, or otherwise obsolete. Subtle formulation changes in available materials that occur without the knowledge of the weapons community for proprietary reasons have frequently affected the long-term performance of materials in the nuclear weapon environment. Significant improvements in performance, lifetime, or production cost can be realized with modern synthesis, modeling, and manufacturing methods. For example, there are currently supply and aging issues associated with the insensitive high explosive formulations LX-17 and PBX 9502 that are based on triaminotrinitrobenzene (TATB) and Kel-F, neither of which are commercially available today. Assuring the reliability of the stockpile through surveillance and regularly scheduled Life Extension Programs is an increasingly expensive endeavor. Transforming our current stockpile surveillance--a system based on destructive testing of increasingly valuable assets--to a system based on embedded sensors has a number of potential advantages that include long-term cost savings, reduced risk associated with asset transportation, state-of-health assessments in the field, and active management of the stockpile.

  3. Shock Initiation and Detonation Properties of Bis-fluorodinitroethyl formal (FEFO)

    NASA Astrophysics Data System (ADS)

    Gibson, L. L.; Sheffield, S. A.; Dattelbaum, D. M.; Stahl, D. B.; Engelke, R.; Shock; Detonation Physics Team

    2011-06-01

    FEFO is a liquid explosive with a density of 1.6 g/cm3 and an energy output somewhat higher than trinitrotoluene (TNT), making it one of the more energetic liquid explosives. Shock initiation experiments were conducted on a two-stage, gas gun using magnetic gauges to measure the wave profiles during a shock-to-detonation transition. Both unreacted Hugoniot data, as well as run-to-detonation measurements were obtained, along with the reactive wave profiles. FEFO was found to initiate by the homogeneous initiation model, as do all other liquid explosives we have studied. The new unreacted Hugoniot points agree with other published data and a universal liquid Hugoniot estimates the Hugoniot data quite well. It is quite insensitive, with about the same shock sensitivity as the triamino-trinitro-benzene-based explosives PBX9502 and LX-17. In addition to the shock initiation experiments, one experiment was done on the gun providing a reasonably accurate detonation velocity and a detonation wave profile. These are compared to the waveforms from the in-situ magnetic gauges, as well as to other data available in the literature.

  4. Initiation Pressure Thresholds from Three Sources

    SciTech Connect

    Souers, P C; Vitello, P

    2007-02-28

    Pressure thresholds are minimum pressures needed to start explosive initiation that ends in detonation. We obtain pressure thresholds from three sources. Run-to-detonation times are the poorest source but the fitting of a function gives rough results. Flyer-induced initiation gives the best results because the initial conditions are the best known. However, very thick flyers are needed to give the lowest, asymptotic pressure thresholds used in modern models and this kind of data is rarely available. Gap test data is in much larger supply but the various test sizes and materials are confusing. We find that explosive pressures are almost the same if the distance in the gap test spacers are in units of donor explosive radius. Calculated half-width time pulses in the spacers may be used to create a pressure-time curve similar to that of the flyers. The very-large Eglin gap tests give asymptotic thresholds comparable to extrapolated flyer results. The three sources are assembled into a much-expanded set of near-asymptotic pressure thresholds. These thresholds vary greatly with density: for TATB/LX-17/PBX 9502, we find values of 4.9 and 8.7 GPa at 1.80 and 1.90 g/cm{sup 3}, respectively.

  5. Dynamic Characterization of Mock Explosive Material Using Reverse Taylor Impact Experiments

    SciTech Connect

    Ferranti, L; Gagliardi, F J; Cunningham, B J; Vandersall, K S

    2010-03-25

    The motivation for the current study is to evaluate the dynamic loading response of an inert mock explosive material used to replicate the physical and mechanical properties of LX-17-1 and PBX 9502 insensitive high explosives. The evaluation of dynamic material parameters is needed for predicting the deformation behavior including the onset of failure and intensity of fragmentation resulting from high velocity impact events. These parameters are necessary for developing and validating physically based material constitutive models that will characterize the safety and performance of energetic materials. The preliminary study uses a reverse Taylor impact configuration that was designed to measure the dynamic behavior of the explosive mock up to and including associated fragmentation. A stationary rod-shaped specimen was impacted using a compressed-gas gun by accelerating a rigid steel anvil attached to a sabot. The impact test employed high-speed imaging and velocity interferometry diagnostics for capturing the transient deformation of the sample at discrete times. Once established as a viable experimental technique with mock explosives, future studies will examine the dynamic response of insensitive high explosives and propellants.

  6. Shock Initiation of Energetic Materials at Different Initial Temperatures

    SciTech Connect

    Urtiew, P A; Tarver, C M

    2005-01-14

    Shock initiation is one of the most important properties of energetic materials, which must transition to detonation exactly as intended when intentionally shocked and not detonate when accidentally shocked. The development of manganin pressure gauges that are placed inside the explosive charge and record the buildup of pressure upon shock impact has greatly increased the knowledge of these reactive flows. This experimental data, together with similar data from electromagnetic particle velocity gauges, has allowed us to formulate the Ignition and Growth model of shock initiation and detonation in hydrodynamic computer codes for predictions of shock initiation scenarios that cannot be tested experimentally. An important problem in shock initiation of solid explosives is the change in sensitivity that occurs upon heating (or cooling). Experimental manganin pressure gauge records and the corresponding Ignition and Growth model calculations are presented for two solid explosives, LX-17 (92.5 % triaminotrinitrobenzene (TATB) with 7.5 % Kel-F binder) and LX-04 (85 % octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) with 15 % Viton binder) at several initial temperatures.

  7. The increased shock sensitivity of PBX 9502 at high temperature

    NASA Astrophysics Data System (ADS)

    Rae, Philip; Baca, Eva; Cartelli, Angelo

    2013-06-01

    It has been shown previously that the shock sensitivity of TATB based PBXs can be significantly increased at elevated temperature. In fact, some researchers have reported that at 250°C the Pop plot for LX-17 (a TATB based composition) overlays the Pop plot for room temperature PBX 9501 (an HMX based composition). The current study made use of the modified LANL small-scale gap test to investigate the shock sensitivity as a function of temperature. The modified gap test inputs an almost planar shock into the acceptor explosive rather than the more usual highly divergent one. This important change not only makes the geometry less sensitive to machining and assembly imperfections than a divergent version, but also allows accurate computer simulation using models calibrated to 1D Pop plot data. In these tests, samples of PBX 9502 were held at temperatures of 180, 200, 230 & 260°C for 30 minutes prior to firing the donor booster. As expected a significant increase in sensitivity was observed, but the material was not as sensitive as PBX 9501 even at 260°C. The method of performing these more complex high temperature gap tests and the accompanying computer modeling of the results will also be presented.

  8. Flight Experiments On Energy Scaling For In-Space Laser Propulsion

    SciTech Connect

    Scharring, Stefan; Eckel, Hans-Albert; Wollenhaupt, Eric; Roeser, Hans-Peter

    2010-05-06

    As a preparatory study on space-borne laser propulsion, flight experiments with a parabolic thruster were carried out on an air cushion table. The thruster was mounted like a sail on a puck, allowing for laser-driven motion in three degrees of freedom (3 DOF) in artificial weightlessness. Momentum coupling is derived from point explosion theory for various parabolic thruster geometries with respect to energy scaling issues. The experimental data are compared with theoretical predictions and with results from vertical free flights. Experimental results for the air-breakdown threshold and POM ablation inside the thruster are compared with fluence data from beam propagation modeling.

  9. System-level design of an RFID sweat electrolyte sensor patch.

    PubMed

    Rose, Daniel P; Ratterman, M; Griffin, Daniel K; Hou, Linlin; Kelley-Loughnane, Nancy; Naik, Rajesh K; Hagen, Joshua A; Papautsky, I; Heikenfeld, Jason

    2014-01-01

    Wearable digital health devices are dominantly found in rigid form factors such as bracelets and pucks. An adhesive RFID sensor bandage (patch) is reported, which can be made completely intimate with human skin, a distinct advantage for chronological monitoring of biomarkers in sweat. In this demonstration, a commercial RFID chip is adapted with minimum components to allow potentiometric sensing of mM ionic solutes in sweat, and surface temperature, as read by an Android smart-phone app (in-vitro tests). PMID:25570878

  10. Catastrophic pediatric sports injuries.

    PubMed

    Luckstead, Eugene F; Patel, Dilip R

    2002-06-01

    The high school sports of wrestling, gymnastics, ice hockey, baseball, track, and cheerleading should receive closer attention to prevent injury. Safer equipment and sport-specific conditioning should be provided and injuries strictly monitored. Greater attention must also be paid to swimming and diving techniques, and continued observation is needed for heat stroke and heat intolerance in sports such as football, wrestling, basketball, track and field, and cross-country. An increased awareness of commotio cordis in sports other than baseball should include ice hockey, football, track field events, and lacrosse. American football because of the sheer numbers and associated catastrophic injury potential must continue to be monitored at the highest medical levels! PMID:12119866

  11. Individual differences in visual information processing rate and the prediction of performance differences in team sports: a preliminary investigation.

    PubMed

    Adam, J J; Wilberg, R B

    1992-06-01

    This study used a backward-masking paradigm to examine individual differences in rate of visual information processing among university basketball, ice hockey and Canadian football players. Displays containing four letters were presented for stimulus durations ranging from 25 to 300 ms. Following stimulus offset, a masking stimulus was presented for 200 ms. The subjects were instructed to write down as many letters as possible from the briefly presented stimulus display on a specially prepared response grid. The results indicated consistent individual differences in rate of visual information processing. More importantly, it was found that rate of visual information processing as indexed by the backward-masking technique, has promising validity for predicting general performance excellence in university ice hockey and basketball players. Individual differences in rate of visual information processing were interpreted as reflecting the operation of attentional factors. PMID:1602528

  12. Using Masculine Capital to Understand the Role of a Sport Program in the Lives of Men From a Western Canadian Inner City.

    PubMed

    Holt, Nicholas L; Scherer, Jay; Koch, Jordan

    2015-10-01

    The purpose of this study was to examine the role of a sport program in the lives of homeless men with severe mental illnesses and addictions. Interviews were conducted with eight men who attended a floor hockey program, and data examined using categorical-content narrative methodology. Five themes captured the role of the floor hockey program in the men's lives: (a) relationships with program leader, (b) therapy, (c) community, (d) action, and (e) achievement. These themes were interpreted using theories of masculinity (Connell, 1995; Gough, 2014). Relationships with the program leader and other men, and ways in which they were allowed to play with physicality, provided opportunities to accumulate masculine capital (i.e., ways in which competence in traditionally masculine behaviors provides masculine credit). Practically, the findings suggest that sport program delivery for men such as those in this study can be enhanced by providing opportunities for accruing masculine capital. PMID:26524098

  13. Protective equipment and the prevention of concussion - what is the evidence?

    PubMed

    Navarro, Rodolfo R

    2011-01-01

    The complex nature of the evaluation and management of concussion lends to controversy, and the immediate and long-term implications still are being investigated. Various types of protective equipment have been used as a means to prevent concussions, and protective equipment is being used more frequently in different sports. Recent investigations have suggested that a protective, but not preventive, effect may be afforded by mouthguard use in rugby players, headgear use in soccer players, and customized mandibular orthotic use in football players. The use of faceshields has not shown a proven benefit in preventing the incidence of sport-related concussion in ice hockey or field hockey participants. Further studies are needed to clarify the role of protective equipment in the prevention of sport-related concussion. PMID:21228647

  14. Age of menarche in various categories of Indian sportswomen.

    PubMed Central

    Sidhu, L. S.; Grewal, R.

    1980-01-01

    Data on the age of menarche has been collected on 264 Indian sportswomen, and 108 girls forming the control group, all hailing from the Punjab, Haryana, chandigarh and Delhi. Outstanding athletes and players of hockey, basketball and volleyball were included. The combined mean age at menarche for sportswomen is 15.21 years and for the control sample is 14.05 years. The differences in the two series are statistically significant. The mean age at menarche in hockey, basketball, volleyball and athletes is found to be 15.15, 15.40, 15.05 and 15.27 years respectively. The differences in these groups, however, are not found to be statistically significant. Images p199-a p199-b PMID:7448486

  15. Catastrophic spine injuries in sports.

    PubMed

    Boden, Barry P; Prior, Chris

    2005-02-01

    Catastrophic spine injuries in sports are rare but tragic events. The sports with the highest risk of catastrophic spinal injuries are football, ice hockey, wrestling, diving, skiing and snowboarding, rugby, cheerleading, and baseball. A common mechanism of injury for all at-risk sports is an axial compression force to the top of the head with the neck slightly flexed. We review common mechanisms of injury and prevention strategies for spine injuries in the at-risk sports. PMID:15659279

  16. [Comparative study of the performance of leather and plastic skate boots].

    PubMed

    Roy, B; Grenier, R

    1982-03-01

    The authors have tried to demonstrate the influence of leather skate boots and plastic boots on the performance of Atome hockey players. Speed tests and joint flexibility tests by means of rotentgenograms showed that besides the speed tests where the leather boot appeared to perform a little better than the plastic boot, no significant difference could be found between both types of boots. It seems to be more a matter of individual choice and adaptation. PMID:7094193

  17. Exposure to Elevated Carbon Monoxide Levels at an Indoor Ice Arena--Wisconsin, 2014.

    PubMed

    Creswell, Paul D; Meiman, Jon G; Nehls-Lowe, Henry; Vogt, Christy; Wozniak, Ryan J; Werner, Mark A; Anderson, Henry

    2015-11-20

    On December 13, 2014, the emergency management system in Lake Delton, Wisconsin, was notified when a male hockey player aged 20 years lost consciousness after participation in an indoor hockey tournament that included approximately 50 hockey players and 100 other attendees. Elevated levels of carbon monoxide (CO) (range = 45 ppm-165 ppm) were detected by the fire department inside the arena. The emergency management system encouraged all players and attendees to seek medical evaluation for possible CO poisoning. The Wisconsin Department of Health Services (WDHS) conducted an epidemiologic investigation to determine what caused the exposure and to recommend preventive strategies. Investigators abstracted medical records from area emergency departments (EDs) for patients who sought care for CO exposure during December 13-14, 2014, conducted a follow-up survey of ED patients approximately 2 months after the event, and conducted informant interviews. Ninety-two persons sought ED evaluation for possible CO exposure, all of whom were tested for CO poisoning. Seventy-four (80%) patients had blood carboxyhemoglobin (COHb) levels consistent with CO poisoning; 32 (43%) CO poisoning cases were among hockey players. On December 15, the CO emissions from the propane-fueled ice resurfacer were demonstrated to be 4.8% of total emissions when actively resurfacing and 2.3% when idling, both above the optimal range of 0.5%-1.0%. Incomplete fuel combustion by the ice resurfacer was the most likely source of elevated CO. CO poisonings in ice arenas can be prevented through regular maintenance of ice resurfacers, installation of CO detectors, and provision of adequate ventilation. PMID:26583915

  18. Summary and agreement statement of the 2nd International Conference on Concussion in Sport, Prague 2004.

    PubMed

    McCrory, P; Johnston, K; Meeuwisse, W; Aubry, M; Cantu, R; Dvorak, J; Graf-Baumann, T; Kelly, J; Lovell, M; Schamasch, P

    2005-04-01

    In November 2001, the 1st International Symposium on Concussion in Sport was held in Vienna, Austria to provide recommendations for the improvement of safety and health of athletes who suffer concussive injuries in ice hockey, football (soccer), and other sports. The 2nd International Symposium on Concussion in Sport was organised by the same group and held in Prague, Czech Republic in November 2004. It resulted in a revision and update of the Vienna consensus recommendations, which are presented here. PMID:15793085

  19. Reanalysis of dose-response data from the Iraqi methylmercury poisoning episode

    SciTech Connect

    Crump, K.; Clewell, H.; Gearhart, J.

    1995-08-01

    Applying a hockey stick parametric dose-response model to data on late or retarded development in Iraqi children exposed in utero to methylmercury, with mercury (Hg) exposure characterized by the peak Hg concentration in mothers` hair during pregnancy, Cox et al. calculated the {open_quotes}best statistical estimate{close_quotes} of the threshold for health effects as 10 ppm Hg in hair with a 95% range of uncertainty of between 0 and 13.6 ppm. A new application of the hockey stick model to the Iraqi data shows, however, that the statistical upper limit of the threshold based on the hockey stick model could be as high as 255 ppm. Futhermore, the maximum likelihood estimate of the threshold using a different parametric model is virtually zero. These and other analyses demonstrate that threshold estimates based on parametric models exhibit high statistical variability and model dependency, and are highly sensitive to the precise definition of an abnormal response. Consequently, they are not a reliable basis for setting a reference dose (RfD) for methylmercury. Benchmark analyses and statistical analyses useful for deriving NOAELs are also presented. We believe these latter analyses-particularly the benchmark analyses-generally form a sounder basis for determining RfDs than the type of hockey stick analysis presented by Cox et al. However, the acute nature of the exposures, as well as other limitations in the Iraqi data suggest that other data may be more appropriate for determining acceptable human exposures to methylmercury. 24 refs., 5 figs., 2 tabs.

  20. Incidence and severity of reported acute sports injuries in 35 sports using insurance registry data.

    PubMed

    Åman, M; Forssblad, M; Henriksson-Larsén, K

    2016-04-01

    Acute injuries in sport are still a problem where limited knowledge of incidence and severity in different sports at national level exists. In Sweden, 80% of the sports federations have their mandatory injury insurance for all athletes in the same insurance company and injury data are systematically kept in a national database. The aim of the study was to identify high-risk sports with respect to incidence of acute and severe injuries in 35 sports reported to the database. The number and incidences of injuries as well as injuries leading to permanent medical impairment (PMI) were calculated during 2008-2011. Each year approximately 12 000 injuries and 1 162 660 licensed athletes were eligible for analysis. Eighty-five percent of the injuries were reported in football, ice hockey, floorball, and handball. The highest injury incidence as well as PMI was in motorcycle, handball, skating, and ice hockey. Females had higher risk of a PMI compared with males in automobile sport, handball, floorball, and football. High-risk sports with numerous injuries and high incidence of PMI injuries were motorcycle, handball, ice hockey, football, floorball, and automobile sports. Thus, these sports ought to be the target of preventive actions at national level. PMID:25850826

  1. Methane flux from sediment into near-bottom water and its variability along the Hel PeninsulaSouthern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Reindl, Andrzej R.; Bola?ek, Jerzy

    2014-02-01

    Methane in the sediments of the Bay of Puck occurs in the form of free gas bubbles and is released from the sediments into near-bottom water in the form of a flux. The sediments of the Bay of Puck also contain methanogens whose biological activity results in the production of methane. Research carried out in the coastal areas of the bay along the Hel Peninsula proved the existence of a methane flux ranging from 0.81 mmol m-2 d-1 to 33.41 mmol m-2 d-1 in 2011, while in 2010 ranged from 0.91 mmol m-2 d-1 to 49.15 mmol m-2 d-1. Seasonal and annual fluctuations were also observed. Other factors contributing to the change in methane flux are water temperature and other environmental factors. An increase in temperature causes an increase in the flux. Fluctuations of the flux within individual sampling sites were also observed. A test performed with specific methanogenic inhibitorsodium dodecyl sulfate (SDS) unexpectedly revealed higher methane concentrations (10-13%) in samples to which SDS was added. We speculate that these higher methane concentration result from the lysis of methane-forming bacteria cells when exposed to SDS.

  2. Analysis of trophic networks and carbon flows in south-eastern Baltic coastal ecosystems

    NASA Astrophysics Data System (ADS)

    Tomczak, Maciej T.; Müller-Karulis, Bärbel; Järv, Leili; Kotta, Jonne; Martin, Georg; Minde, Atis; Põllumäe, Arno; Razinkovas, Arturas; Strake, Solvita; Bucas, Martynas; Blenckner, Thorsten

    2009-04-01

    Carbon flows in five south-eastern Baltic coastal ecosystems (Puck Bay, Curonian Lagoon, Lithuanian coast, Gulf of Riga coast and Pärnu Bay) were compared on the basis of ECOPATH models using 12 common functional groups. The studied systems ranged from the hypertrophic Curonian Lagoon to the mesotrophic Gulf of Riga coast. Interestingly, we found that macrophytes were not consumed by grazers, but rather channelled into the detritus food chain. In all ecosystems fisheries had far reaching impacts on their target species and on the food-web in general. In particular, benthic food-webs were partly affected by indirect fisheries effects. For example, fisheries tend to change the biomass of piscivorous fish, causing a cascading effect on benthivorous fish and macrozoobenthos. These cascades are ecosystem specific and need to be considered when using benthic invertebrates as productivity and eutrophication indicators. Odum’s maturity attributes allowed a ranking of costal ecosystems according to their maturity. Namely, the community development decreased in the following order: Pärnu Bay > Gulf of Riga coast > Lithuanian coast > Puck Bay > Curonian Lagoon.

  3. WRAP low level waste (LLW) glovebox operational test report

    SciTech Connect

    Kersten, J.K.

    1998-02-19

    The Low Level Waste (LLW) Process Gloveboxes are designed to: receive a 55 gallon drum in an 85 gallon overpack in the Entry glovebox (GBIOI); and open and sort the waste from the 55 gallon drum, place the waste back into drum and relid in the Sorting glovebox (GB 102). In addition, waste which requires further examination is transferred to the LLW RWM Glovebox via the Drath and Schraeder Bagiess Transfer Port (DO-07-201) or sent to the Sample Transfer Port (STC); crush the drum in the Supercompactor glovebox (GB 104); place the resulting puck (along with other pucks) into another 85 gallon overpack in the Exit glovebox (GB 105). The status of the waste items is tracked by the Data Management System (DMS) via the Plant Control System (PCS) barcode interface. As an item is moved from the entry glovebox to the exit glovebox, the Operator will track an items location using a barcode reader and enter any required data on the DMS console. The Operational Test Procedure (OTP) will perform evolution`s (described below) using the Plant Operating Procedures (POP) in order to verify that they are sufficient and accurate for controlled glovebox operation.

  4. Molecular Adsorber Coating

    NASA Technical Reports Server (NTRS)

    Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory

    2011-01-01

    A document discusses a zeolite-based sprayable molecular adsorber coating that has been developed to alleviate the size and weight issues of current ceramic puck-based technology, while providing a configuration that more projects can use to protect against degradation from outgassed materials within a spacecraft, particularly contamination-sensitive instruments. This coating system demonstrates five times the adsorption capacity of previously developed adsorber coating slurries. The molecular adsorber formulation was developed and refined, and a procedure for spray application was developed. Samples were spray-coated and tested for capacity, thermal optical/radiative properties, coating adhesion, and thermal cycling. Work performed during this study indicates that the molecular adsorber formulation can be applied to aluminum, stainless steel, or other metal substrates that can accept silicate-based coatings. The coating can also function as a thermal- control coating. This adsorber will dramatically reduce the mass and volume restrictions, and is less expensive than the currently used molecular adsorber puck design.

  5. A Prospective Pilot Investigation of Brain Volume, White Matter Hyperintensities, and Hemorrhagic Lesions after Mild Traumatic Brain Injury

    PubMed Central

    Jarrett, Michael; Tam, Roger; Hernández-Torres, Enedino; Martin, Nancy; Perera, Warren; Zhao, Yinshan; Shahinfard, Elham; Dadachanji, Shiroy; Taunton, Jack; Li, David K. B.; Rauscher, Alexander

    2016-01-01

    Traumatic brain injury (TBI) is among the most common neurological disorders. Hemorrhagic lesions and white matter hyperintensities (WMH) are radiological features associated with moderate and severe TBI. Brain volume reductions have also been observed during the months following injury. In concussion, no signs of injury are observed on conventional magnetic resonance imaging (MRI), which may be a true feature of concussion or merely due to the limited sensitivity of imaging techniques used so far. Moreover, it is not known whether volume reductions are due to the resolution of trauma-related edema or a true volume loss. Forty-five collegiate-level ice hockey players (20 females) and 15 controls (9 females), 40 players underwent 3-T MRI for hemorrhages [multi-echo susceptibility-weighted imaging (SWI)], WMH (three-dimensional fluid-attenuated inversion recovery), and brain volume at the beginning and the end of the hockey season. Concussed athletes underwent additional imaging and neuropsychological testing at 3 days, 2 weeks, and 2 months after injury. At the end of the hockey season, brain volume was reduced compared to controls by 0.32% (p < 0.034) in the whole cohort and by 0.26% (p < 0.09) in the concussed athletes. Two weeks and 2 months after concussion, brain volume was reduced by −0.08% (p = 0.027) and −0.23% (p = 0.035), respectively. In athletes, the WMH were significantly closer to the interface between gray matter and white matter compared to controls. No significant changes in the number of WMH over the duration of the study were found in athletes. No microhemorrhages were detected as a result of concussion or playing a season of ice hockey. We conclude that mild TBI does not lead to transient increases in brain volume and no new microbleeds or WMH are detectable after concussion. Brain volume reductions appear by 2 weeks after concussion and persist until at least 2 months after concussion. Brain volume is reduced between the beginning and the end of the ice hockey season. PMID:26903944

  6. OGC standards for end-to-end sensor network integration

    NASA Astrophysics Data System (ADS)

    Headley, K. L.; Broering, A.; O'Reilly, T. C.; Toma, D.; Del Rio, J.; Bermudez, L. E.; Zedlitz, J.; Johnson, G.; Edgington, D.

    2010-12-01

    Many sensor networks have been deployed to monitor Earth's environment, and more are planned for the future. Environmental sensors have continuously improved by becoming smaller, cheaper, more intelligent, and more reliable. But due to the large number of sensor manufacturers and accompanying protocols, integrating diverse sensors into observing systems is not straightforward, requiring development of driver software and manual tedious configuration. Use of standard protocols and formats can improve and automate the process of sensor installation, operation, and data processing. The Open Geospatial Consortium's Sensor Web Enablement (SWE) initiative defines standards which make sensors available over the Web through standardized formats and Web Service interfaces by hiding the heterogeneity of sensor protocols from the application layer. Current SWE standards do not deal with actual sensor protocols, and the connection between sensors and SWE services is usually established by manually adapting the internals of the SWE service implementation to the specific sensor interface. Such sensor "drivers" have to be built for each kind of sensor interface, which leads to extensive efforts in developing large-scale systems. To tackle this issue we have developed a model for Sensor Interface Descriptors (SID) which enables the declarative description of sensor interfaces, including the definition of the communication protocol, sensor commands, processing steps and metadata association. The model is designed as a profile and extension of OGC SWE's Sensor Model Language standard. In this model, a SID is defined in XML for each kind of sensor protocol. SID instances for particular sensor types can be reused in different scenarios and can be shared among user communities. A SID interpreter can be built which translates between various sensor protocols and SWE protocols, hence closing the described interoperability gap. The SID interpreter is independent of any particular sensor technology, and can communicate with any sensor whose protocol can be described by a SID. The SID interpreter transfers retrieved sensor data to a Sensor Observation Service, and transforms tasks submitted to a Sensor Planning Service to actual sensor commands. The proposed SWE PUCK protocol complements SID by providing a standard way to associate a sensor with a SID, thereby completely automating the sensor integration process. PUCK protocol is implemented in sensor firmware, and provides a means to retrieve a universally unique identifer, metadata and other information from the device itself through its communication interface. Thus the SID interpreter can retrieve a SID directly from the sensor through PUCK protocol. Alternatively the interpreter can retrieve the sensors SID from an external source, based on the unique sensor ID provided by PUCK protocol. In this presentation, we describe the end-to-end integration of several commercial oceanographic instruments into a sensor network using PUCK, SID and SWE services. We also present a user-friendly, graphical tool to generate SIDs and tools to visualize sensor data.

  7. Kinetic Modeling of Slow Energy Release in Non-Ideal Carbon Rich Explosives

    SciTech Connect

    Vitello, P; Fried, L; Glaesemann, K; Souers, C

    2006-06-20

    We present here the first self-consistent kinetic based model for long time-scale energy release in detonation waves in the non-ideal explosive LX-17. Non-ideal, insensitive carbon rich explosives, such as those based on TATB, are believed to have significant late-time slow release in energy. One proposed source of this energy is diffusion-limited growth of carbon clusters. In this paper we consider the late-time energy release problem in detonation waves using the thermochemical code CHEETAH linked to a multidimensional ALE hydrodynamics model. The linked CHEETAH-ALE model dimensional treats slowly reacting chemical species using kinetic rate laws, with chemical equilibrium assumed for species coupled via fast time-scale reactions. In the model presented here we include separate rate equations for the transformation of the un-reacted explosive to product gases and for the growth of a small particulate form of condensed graphite to a large particulate form. The small particulate graphite is assumed to be in chemical equilibrium with the gaseous species allowing for coupling between the instantaneous thermodynamic state and the production of graphite clusters. For the explosive burn rate a pressure dependent rate law was used. Low pressure freezing of the gas species mass fractions was also included to account for regions where the kinetic coupling rates become longer than the hydrodynamic time-scales. The model rate parameters were calibrated using cylinder and rate-stick experimental data. Excellent long time agreement and size effect results were achieved.

  8. Recent advances in the molten salt technology for the destruction of energetic materials

    SciTech Connect

    Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.

    1995-11-01

    The DOE has thousands of pounds of energetic materials which result from dismantlement operations at the Pantex Plant. The authors have demonstrated the Molten Salt Destruction (MSD) Process for the treatment of explosives and explosive-containing wastes on a 1.5 kilogram of explosive per hour scale and are currently building a 5 kilogram per hour unit. MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen and water. Any inorganic constituents of the waste, such as binders and metallic particles, are retained in the molten salt. The destruction of energetic material waste is accomplished by introducing it, together with air, into a crucible containing a molten salt, in this case a eutectic mixture of Na, K, and Li carbonates. The following pure component DOE and DoD explosives have been destroyed in LLNL`s experimental unit at their High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K-6, NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following formulations were also destroyed: Comp B, LX-10, LX-16, LX-17, PBX-9404, and XM46, a US Army liquid gun propellant. In this 1.5 kg/hr unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NOx were found to be well below 1T. In addition to destroying explosive powders and molding powders the authors have also destroyed materials that are typical of real world wastes. These include shavings from machined pressed parts of plastic bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the information obtained on the smaller unit, the authors have constructed a 5 kg/hr MSD unit, incorporating LLNL`s advanced chimney design. This unit is currently under shakedown tests and evaluation.

  9. Fatigue of LX-14 and LX-19 plastic bonded explosives

    SciTech Connect

    Hoffman, D. M., LLNL

    1998-04-23

    The DOD uses the plastic bonded explosive (PBX) LX-14 in a wide variety of applications including shaped charges and explosively forged projectiles. LX- 19 is a higher energy explosive, which could be easily substituted for LX-14 because it contains the identical Estane 5703p binder and more energetic CL-20 explosive. Delivery systems for large shaped charges, such as TOW-2, include the Apache helicopter. Loads associated with vibrations and expansion from thermal excursions in field operations may, even at low levels over long time periods, cause flaws, already present in the PBX to grow. Flaws near the explosive/liner interface of a shaped charge can reduce performance. Small flaws in explosives are one mechanism (the hot spot mechanism) proposed for initiation and growth to detonation of PBXs like LX-14, PBXN 5, LX-04 and LX-17 among others. Unlike cast-cured explosives and propellants, PBXs cannot usually be compression molded to full density. Generally, the amount of explosive ignited by a shock wave is approximately equal to the original void volume. Whether or not these flaws or cracks grow during field operations to an extent sufficient to adversely affect the shaped charge performance or increase the vulnerability of the PBX is the ultimate question this effort could address. Currently the fatigue life of LX-14 under controlled conditions is being studied in order to generate its failure stress as a function of the number of fatigue cycles (S- N curve). Proposed future work will address flaw and crack growth and their relationship to hot-spot concentration and explosive vulnerability to shock and/or fragment initiation.

  10. Laser cutting of pressed explosives: Revision 1

    SciTech Connect

    Roeske, F., Jr.; Banks, R.E.; Armstrong, J.P.; Feit, M.D.; Lee, R.S.; Perry, M.D.; Stuart, B.C.

    1998-05-04

    We have used a femtosecond laser beam to make cuts through small pressed pellets of six common explosives. The laser system, which produces 100 fs pulses of 820 nm light at a repitition rate of 1 kHz, was intitially developed for cutting metal. The advantage of using a femtosecond laser for cutting is that the cutting process transfers virtually no heat to the material that is being cut and produces almost no waste. We used LX-16 explosive (96% PETN/4% FPC 461 binder) for out intial experiments because PETN is one of the most sensitve of the secondary explosives. In some of the experiments the beam first cut through the HE pellet and then through a stainless steel substrate and in other experiments the beam first cut through the stainless steel and then through the pellet. We also cut through pellets that were not backed by a substrate. No evidence of reaction was observed in any of the LX-16 pellets. In addition to LX-16 we cut pellets of LX-14 (95.5% HMX/4.5% Estane), LX-15 (95% HNS/5% Kel-F), LX-17 (92.5% TATB/7.5% Kel-F), PBX-9407 (94% RDX/6% Exon 461), and pressed TNT with no evidence of reaction. The HE was easily cut at low power levels with one or two sweeps at 0.5 W average power sufficing to cut most of the pellets. There is obvioulsy much more work to be done before laser machining of explosives becomes a reality, but the results of these intitial experiments indicate that laser machining of explosives may be an attractive option for explosives processing.

  11. Neutron Screening Measurements of 110 gallon drums at T Plant

    SciTech Connect

    Mozhayev, Andrey V.; Hilliard, James R.; Berg, Randal K.

    2011-01-14

    The Pacific Northwest National Laboratory (PNNL) Nondestructive Assay (NDA) Service Center was contracted to develop and demonstrate a simple and inexpensive method of assaying 110 gallon drums at the Hanford Sites T-Plant. The drums contained pucks of crushed old drums used for storage of transuranic (TRU) waste. The drums were to be assayed to determine if they meet the criteria for TRU or Low Level Waste (LLW). Because of the dense matrix (crushed steel drums) gamma measurement techniques were excluded and a mobile, configurable neutron system, consisting of four sequentially connected slab detectors was chosen to be used for this application. An optimum measurement configuration was determined through multiple test measurements with californium source. Based on these measurements the initial calibration of the system was performed applying the isotopic composition for aged weapon-grade plutonium. A series of background and blank puck drum measurements allowed estimating detection limits for both total (singles) and coincidence (doubles) counting techniques. It was found that even conservative estimates for minimum detection concentration using singles count rate were lower than the essential threshold of 100 nCi/g. Whereas the detection limit of coincidence counting appeared to be about as twice as high of the threshold. A series of measurements intended to verify the technique and revise the initial calibration obtained were performed at the Waste Receiving and Processing (WRAP) facility with plutonium standards. Standards with a total mass of 0.3 g of plutonium (which is estimated to be equivalent of 100 nCi/g for net waste weight of 300 kg) loaded in the test puck drum were clearly detected. The following measurements of higher plutonium loadings verified the calibration factors obtained in the initial exercise. The revised and established calibration factors were also confirmed within established uncertainties by additional measurements of plutonium standards in various locations in the test drum. Due to necessity to dispense the blank test drum an alternative method of baseline determination was established during field measurements. Count rates of ambient background were corrected by the differences between observed background and blank test drum count rates which were previously determined over a series of measurements. Only 31 drums out of 352 counted during the intensive measurement campaign at T-Plant were determined to be Suspect TRU. 25 of these drums were re-measured at the WRAP facility using the SuperHENC. Of the 25 drums measured, 21 were confirmed to be TRU and the remaining four LLW.

  12. Comparison of Recent Modeled and Observed Trends in Total Column Ozone

    NASA Technical Reports Server (NTRS)

    Andersen, S. B.; Weatherhead, E. C.; Stevermer, A.; Austin, J.; Bruehl, C.; Fleming, E. L.; deGrandpre, J.; Grewe, V.; Isaksen, I.; Pitari, G.; Portmann, R. W.; Rognerud, B.; Rosenfield, J. E.; Smyshlyaev, S.; Nagashima, T.; Velders, G. J. M.; Weisenstein, D. K.; Xia, J.

    2006-01-01

    We present a comparison of trends in total column ozone from 10 two-dimensional and 4 three-dimensional models and solar backscatter ultraviolet-2 (SBUV/2) satellite observations from the period 1979-2003. Trends for the past (1979-2000), the recent 7 years (1996-2003), and the future (2000-2050) are compared. We have analyzed the data using both simple linear trends and linear trends derived with a hockey stick method including a turnaround point in 1996. If the last 7 years, 1996-2003, are analyzed in isolation, the SBUV/2 observations show no increase in ozone, and most of the models predict continued depletion, although at a lesser rate. In sharp contrast to this, the recent data show positive trends for the Northern and the Southern Hemispheres if the hockey stick method with a turnaround point in 1996 is employed for the models and observations. The analysis shows that the observed positive trends in both hemispheres in the recent 7-year period are much larger than what is predicted by the models. The trends derived with the hockey stick method are very dependent on the values just before the turnaround point. The analysis of the recent data therefore depends greatly on these years being representative of the overall trend. Most models underestimate the past trends at middle and high latitudes. This is particularly pronounced in the Northern Hemisphere. Quantitatively, there is much disagreement among the models concerning future trends. However, the models agree that future trends are expected to be positive and less than half the magnitude of the past downward trends. Examination of the model projections shows that there is virtually no correlation between the past and future trends from the individual models.

  13. Mechanisms of Team-Sport-Related Brain Injuries in Children 5 to 19 Years Old: Opportunities for Prevention

    PubMed Central

    Cusimano, Michael D.; Cho, Newton; Amin, Khizer; Shirazi, Mariam; McFaull, Steven R.; Do, Minh T.; Wong, Matthew C.; Russell, Kelly

    2013-01-01

    Background There is a gap in knowledge about the mechanisms of sports-related brain injuries. The objective of this study was to determine the mechanisms of brain injuries among children and youth participating in team sports. Methods We conducted a retrospective case series of brain injuries suffered by children participating in team sports. The Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) database was searched for brain injury cases among 5–19 year-olds playing ice hockey, soccer, American football (football), basketball, baseball, or rugby between 1990 and 2009. Mechanisms of injury were classified as “struck by player,” “struck by object,” “struck by sport implement,” “struck surface,” and “other.” A descriptive analysis was performed. Results There were 12,799 brain injuries related to six team sports (16.2% of all brain injuries registered in CHIRPP). Males represented 81% of injuries and the mean age was 13.2 years. Ice hockey accounted for the greatest number of brain injuries (44.3%), followed by soccer (19.0%) and football (12.9%). In ice hockey, rugby, and basketball, striking another player was the most common injury mechanism. Football, basketball, and soccer also demonstrated high proportions of injuries due to contact with an object (e.g., post) among younger players. In baseball, a common mechanism in the 5–9 year-old group was being hit with a bat as a result of standing too close to the batter (26.1% males, 28.3% females). Interpretation Many sports-related brain injury mechanisms are preventable. The results suggest that further efforts aimed at universal rule changes, safer playing environments, and the education of coaches, players, and parents should be targeted in maximizing prevention of sport-related brain injury using a multifaceted approach. PMID:23555602

  14. Spinal injuries in sports.

    PubMed

    Boden, Barry P; Jarvis, Christopher G

    2008-02-01

    Athletic competition has long been a known source of spinal injuries. Approximately 8.7% of all new cases of spinal cord injuries in the United States are related to sports activities. The sports activities that have the highest risk of catastrophic spinal injuries are football, ice hockey, wrestling, diving, skiing, snowboarding, rugby, and cheerleading. Axial compression forces to the top of the head can lead to cervical fracture and quadriplegia in any sport. It is critical for any medical personnel responsible for athletes in team sports to have a plan for stabilization and transfer of an athlete who sustains a cervical spine injury. PMID:18295084

  15. Spinal injuries in sports.

    PubMed

    Boden, Barry P; Jarvis, Christopher G

    2009-02-01

    Athletic competition has long been a known source of spinal injuries. Approximately 8.7% of all new cases of spinal cord injuries in the United States are related to sports activities. The sports activities that have the highest risk of catastrophic spinal injuries are football, ice hockey, wrestling, diving, skiing, snowboarding, rugby, and cheerleading. Axial compression forces to the top of the head can lead to cervical fracture and quadriplegia in any sport. It is critical for any medical personnel responsible for athletes in team sports to have a plan for stabilization and transfer of an athlete who sustains a cervical spine injury. PMID:19084763

  16. Ferroelectric Smectic Phase Formed by Achiral Straight Core Mesogens

    NASA Astrophysics Data System (ADS)

    Stannarius, Ralf; Li, Jianjun; Weissflog, Wolfgang

    2003-01-01

    We report electro-optic experiments in liquid crystalline freestanding films of achiral hockey stick shaped mesogens with a straight aromatic core. The material forms two smectic mesophases. In the higher temperature phase, a spontaneous polarization exists in the smectic layer plane and the films show polar switching in electric fields. It is the first example of a ferroelectric phase formed by nearly rodlike achiral mesogens. Mirror symmetry of the phase is spontaneously broken. We propose a molecular configuration similar to a synclinic ferroelectric (CSPF) high temperature phase and an anticlinic, probably antiferroelectric (CAPA) low temperature phase.

  17. Altitude training considerations for the winter sport athlete.

    PubMed

    Chapman, Robert F; Stickford, Jonathon L; Levine, Benjamin D

    2010-03-01

    Winter sports events routinely take place at low to moderate altitudes, and nearly all Winter Olympic Games have had at least one venue at an altitude >1000 m. The acute and chronic effects of altitude can have a substantial effect on performance outcomes. Acutely, the decline in oxygen delivery to working muscle decreases maximal oxygen uptake, negatively affecting performance in endurance events, such as cross-country skiing and biathlon. The reduction in air resistance at altitude can dramatically affect sports involving high velocities and technical skill components, such as ski jumping, speed skating, figure skating and ice hockey. Dissociation between velocity and sensations usually associated with work intensity (ventilation, metabolic signals in skeletal muscle and heart rate) may impair pacing strategy and make it difficult to determine optimal race pace. For competitions taking place at altitude, a number of strategies may be useful, depending on the altitude of residence of the athlete and ultimate competition altitude, as follows. First, allow extra time and practice (how much is yet undetermined) for athletes to adjust to the changes in projectile motion; hockey, shooting, figure skating and ski jumping may be particularly affected. These considerations apply equally in the reverse direction; that is, for athletes practising at altitude but competing at sea level. Second, allow time for acclimatization for endurance sports: 3-5 days if possible, especially for low altitude (500-2000 m); 1-2 weeks for moderate altitude (2000-3000 m); and at least 2 weeks if possible for high altitude (>3000 m). Third, increase exercise-recovery ratios as much as possible, with 1:3 ratio probably optimal, and consider more frequent substitutions for sports where this is allowed, such as ice hockey. Fourth, consider the use of supplemental O(2) on the sideline (ice hockey) or in between heats (skating and Alpine skiing) to facilitate recovery. For competitions at sea level, the 'live high-train low' model of altitude training can help athletes in endurance events to maximize performance. PMID:19837773

  18. Understanding the petrochemical cycle: Part 1

    SciTech Connect

    Sedriks, W. )

    1994-03-01

    Fitness in the hydrocarbon processing industry (HPI) arena involves understanding and coping with business cycles: supply and demand. This becomes increasingly more important as the industry globalizes and matures. Competitive-edge thinking needs to look hard at the forces that influence business cycles. Recognition of potential pitfalls is very important when considering: future capacity expansion, mergers and acquisitions, market departure, plant closure, potential product substitution, etc. Understanding pricing mechanisms and the workings of hockey-stick profitability profiles help HPI operators endure cycle downturns and prepare plants to maximize profits for the next upswing. The paper discusses characteristic trends, cycles in the hydrocarbon processing industry, current conditions, and mitigating cycle effects.

  19. The Avoidance and Management of Orofacial Injuries

    PubMed Central

    Millman, G. David

    1977-01-01

    Recent studies reveal an increasing incidence of orofacial injuries in sports, especially hockey, and physicians must be prepared to accept a role in the campaign to prevent these injuries which are most common at ages 11 to 18. Some aspects of head and orofacial protection are therefore discussed. For those injuries which do occur, proper immediate care may aid in early diagnosis and treatment, and also shorten the recovery period. But perhaps more important, there must also be a change in our attitudes towards sports. ImagesFig. 1Fig. 2 PMID:21304782

  20. What is the most interesting team sport?

    NASA Astrophysics Data System (ADS)

    Vazquez, Federico; Ben-Naim, Eli; Redner, Sidney

    2006-03-01

    What is the most interesting team sport? We answer this question via an extensive statistical survey of game scores, consisting of more than 1/4 million games in over a century. We propose the likelihood of upsets as a measure of competitiveness. We demonstrate the utility of this measure via a comparative analysis of several popular team sports including soccer, baseball, hockey, basketball, and football. We also develop a mathematical model, in which the stronger team is favored to win a game. This model allows to us conveniently estimate the likelihood of upsets from the more easily-accessible standings data.

  1. The "Buy-Max" mouthguard: oral, peri-oral and cerebral protection for contact sports.

    PubMed

    Porter, M; O'Brien, M

    1994-01-01

    Protective equipment plays an important role in the reduction of certain sports injuries. Mouthguards have been shown to reduce the number of orafacial and cerebral injuries in a variety of contact sports including rugby, hockey and boxing. The varieties of mouthguards available are discussed. The most effective, but also the most expensive, is the "Bimaxillary" mouthguard popularised by Chapman. It covers both dental arches and as the jaws are held in the position of heavy breathing, air flow is not impeded. The advantages and disadvantages of the various types of mouthguard are discussed. PMID:8975055

  2. "Fever in the Hand"

    PubMed

    Silber

    1996-10-01

    A 14-year-old female adolescent was being treated for malnutrition secondary to anorexia nervosa. She complained of severe "shooting" pain, swelling, and color and temperature changes in her left (dominant) hand. She had recently suffered a fall during a hockey game and pounded on the table during a "temper tantrum." On exam, the left hand was cyanotic, edematous, and cold, with severe hyperesthesia. A bone scan showed marked reduction in flow to the left hand. She underwent eight sympathetic ganglion blocks resulting in transitory Horner's syndrome. Favorable plethysmographic changes occurred and her recovery was complete. Her eventual diagnosis was reflex sympathetic dystrophy syndrome. PMID:10360004

  3. Isolated rupture of the subscapularis tendon in children: a case report and literature review.

    PubMed

    Gouron, Richard; Deroussen, Franois; Juvet-Segarra, Marie; Mancheron, Catherine; Bonnaire, Bruno; Collet, Louis-Michel

    2013-03-01

    We report the case of an 11-year-old, male, competitive hockey player with a complete rupture of the subscapularis insertion but no avulsion fracture of the lesser tuberosity. Ultrasound and MRI were performed before surgical repair with suture anchors. The boy regained a normal range of movement after 4 weeks of immobilization and 2 months of rehabilitation. This unique case (with the absence of lesser tuberosity avulsion) is compared with the 16 other cases of paediatric subscapularis avulsion fracture reported in the literature. PMID:23197182

  4. Rumination and Performance in Dynamic, Team Sport

    PubMed Central

    Roy, Michael M.; Memmert, Daniel; Frees, Anastasia; Radzevick, Joseph; Pretz, Jean; Noël, Benjamin

    2016-01-01

    People high in rumination are good at tasks that require persistence whereas people low in rumination is good at tasks that require flexibility. Here we examine real world implications of these differences in dynamic, team sport. In two studies, we found that professional male football (soccer) players from Germany and female field hockey players on the US national team were lower in rumination than were non-athletes. Further, low levels of rumination were associated with a longer career at a higher level in football players. Results indicate that athletes in dynamic, team sport might benefit from the flexibility associated with being low in rumination. PMID:26779110

  5. Remotely controlling of mobile robots using gesture captured by the Kinect and recognized by machine learning method

    NASA Astrophysics Data System (ADS)

    Hsu, Roy CHaoming; Jian, Jhih-Wei; Lin, Chih-Chuan; Lai, Chien-Hung; Liu, Cheng-Ting

    2013-01-01

    The main purpose of this paper is to use machine learning method and Kinect and its body sensation technology to design a simple, convenient, yet effective robot remote control system. In this study, a Kinect sensor is used to capture the human body skeleton with depth information, and a gesture training and identification method is designed using the back propagation neural network to remotely command a mobile robot for certain actions via the Bluetooth. The experimental results show that the designed mobile robots remote control system can achieve, on an average, more than 96% of accurate identification of 7 types of gestures and can effectively control a real e-puck robot for the designed commands.

  6. Perioperative registered nurse excellence. Raising the bar at the point of care--star performance.

    PubMed

    Shewchuk, Muriel

    2014-06-01

    As described, the responsibilities of the Perioperative RN are extensive, complex, time-sensitive, can impact a large number of patients and multi-professionals. In a time of tremendous pressures in health care, with patient safety as a focus, there is an expectation of practice excellence throughout. Registered Nurses need to determine if they can, or are willing to, achieve excellence of practice in the OR. Our reason for being is "THE PATIENT". Strategize how you will achieve the bar of excellence and in the words of Wayne Gretzky--"skate to where the puck will be." Shower your environment with positive sprinklings of star performance--the return professional profits are immeasurable. PMID:25080781

  7. Children's Perception and Interpretation of Robots and Robot Behaviour

    NASA Astrophysics Data System (ADS)

    Bhamjee, Sajida; Griffiths, Frances; Palmer, Julie

    Technology is advancing rapidly; especially in the field of robotics. The purpose of this study was to examine children's perception and interpretation of robots and robot behaviour. The study was divided into two phases: phase one involved 144 children (aged 7-8) from two primary schools drawing a picture of a robot and then writing a story about the robot that they had drawn. In phase two, in small groups, 90 children observed four e-puck robots interacting within an arena. The children were asked three questions during the observation: 'What do you think the robots are doing?', 'Why are they doing these things?' and 'What is going on inside the robot?' The results indicated that children can hold multiple understandings of robots simultaneously. Children tend to attribute animate characteristics to robots. Although this may be explained by their stage of development, it may also influence how their generation integrates robots into society.

  8. Event detection and localization for small mobile robots using reservoir computing.

    PubMed

    Antonelo, E A; Schrauwen, B; Stroobandt, D

    2008-08-01

    Reservoir Computing (RC) techniques use a fixed (usually randomly created) recurrent neural network, or more generally any dynamic system, which operates at the edge of stability, where only a linear static readout output layer is trained by standard linear regression methods. In this work, RC is used for detecting complex events in autonomous robot navigation. This can be extended to robot localization tasks which are solely based on a few low-range, high-noise sensory data. The robot thus builds an implicit map of the environment (after learning) that is used for efficient localization by simply processing the input stream of distance sensors. These techniques are demonstrated in both a simple simulation environment and in the physically realistic Webots simulation of the commercially available e-puck robot, using several complex and even dynamic environments. PMID:18662855

  9. Finite element analysis of hypervelocity impact behaviour of CFRP-Al/HC sandwich panel

    NASA Astrophysics Data System (ADS)

    Phadnis, Vaibhav A.; Silberschmidt, Vadim V.

    2015-09-01

    The mechanical response of CFRP-Al/HC (carbon fibre-reinforced/epoxy composite face sheets with Al honeycomb core) sandwich panels to hyper-velocity impact (up to 1 km/s) is studied using a finite-element model developed in ABAQUS/Explicit. The intraply damage of CFRP face sheets is analysed by mean of a user-defined material model (VUMAT) employing a combination of Hashin and Puck criteria, delamination modelled using cohesive-zone elements. The damaged Al/HC core is assessed on the basis of a Johnson Cook dynamic failure model while its hydrodynamic response is captured using the Mie-Gruneisen equation of state. The results obtained with the developed finite-element model showed a reasonable correlation to experimental damage patterns. The surface peeling of both face sheets was evident, with a significant delamination around the impact location accompanied by crushing HC core.

  10. Evaluation of distributed smart sensor interfaces to improve traditional data acquisition systems

    NASA Astrophysics Data System (ADS)

    Chayes, D. N.

    2005-12-01

    The snowballing effort to establish environmental observing systems will (is already?) overwhelming our ability to maintain accurate instrument metadata from acquisition through archiving and delivery to end users. Traditionally this issue has been addressed by labor intensive and sometimes relatively ad hoc approaches typified by custom, proprietary, poorly documented data systems based on simple asynchronous point to point protocols such as RS-232. While there is a broad range of "standards", many of which have demonstrated effective use such as the Serial Ascii Instrumentation Loop (SAIL), NMEA0183, and SDI-12 to name a few, but none that have been widely implemented across disciplnes due to a not well characterized collection of barriers. Currently evolving efforts including IEEE-1451 and the MBARI-led PUCK effort show signficant promise. In the context enhancing the reliability of an evolving shipboard data acquistion system a number of options are being explored in order to clarify these barriers with the intent of removing at least some.

  11. Automated sample mounting and technical advance alignment system for biological crystallography at a synchrotron source

    SciTech Connect

    Snell, Gyorgy; Cork, Carl; Nordmeyer, Robert; Cornell, Earl; Meigs, George; Yegian, Derek; Jaklevic, Joseph; Jin, Jian; Stevens, Raymond C.; Earnest, Thomas

    2004-01-07

    High-throughput data collection for macromolecular crystallography requires an automated sample mounting system for cryo-protected crystals that functions reliably when integrated into protein-crystallography beamlines at synchrotrons. Rapid mounting and dismounting of the samples increases the efficiency of the crystal screening and data collection processes, where many crystals can be tested for the quality of diffraction. The sample-mounting subsystem has random access to 112 samples, stored under liquid nitrogen. Results of extensive tests regarding the performance and reliability of the system are presented. To further increase throughput, we have also developed a sample transport/storage system based on ''puck-shaped'' cassettes, which can hold sixteen samples each. Seven cassettes fit into a standard dry shipping Dewar. The capabilities of a robotic crystal mounting and alignment system with instrumentation control software and a relational database allows for automated screening and data collection to be developed.

  12. Development and testing of molecular adsorber coatings

    NASA Astrophysics Data System (ADS)

    Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

    2012-10-01

    The effect of on-orbit molecular contamination has the potential to degrade the performance of spaceflight hardware and diminish the lifetime of the spacecraft. For example, sensitive surfaces, such as optical surfaces, electronics, detectors, and thermal control surfaces, are vulnerable to the damaging effects of contamination from outgassed materials. The current solution to protect these surfaces is through the use of zeolite coated ceramic adsorber pucks. However, these pucks and its additional complex mounting hardware requirements result in several disadvantages, such as size, weight, and cost related concerns, that impact the spacecraft design and the integration and test schedule. As a result, a new innovative molecular adsorber coating was developed as a sprayable alternative to mitigate the risk of on-orbit molecular contamination. In this study, the formulation for molecular adsorber coatings was optimized using various binders, pigment treatment methods, binder to pigment ratios, thicknesses, and spray application techniques. The formulas that passed coating adhesion and vacuum thermal cycling were further tested for its adsorptive capacity. Accelerated molecular capacitance tests were performed in an innovatively designed multi-unit system containing idealized contaminant sources. This novel system significantly increased the productivity of the testing phase for the various formulations that were developed. Work performed during the development and testing phases has demonstrated successful application of molecular adsorber coatings onto metallic substrates, as well as, very promising results for the adhesion performance and the molecular capacitance of the coating. Continued testing will assist in the qualification of molecular adsorber coatings for use on future contamination sensitive spaceflight missions.

  13. Development and Testing of Molecular Adsorber Coatings

    NASA Technical Reports Server (NTRS)

    Abraham, Nithin; Hasegawa, Mark; Straka, Sharon

    2012-01-01

    The effect of on-orbit molecular contamination has the potential to degrade the performance of spaceflight hardware and diminish the lifetime of the spacecraft. For example, sensitive surfaces, such as optical surfaces, electronics, detectors, and thermal control surfaces, are vulnerable to the damaging effects of contamination from outgassed materials. The current solution to protect these surfaces is through the use of zeolite coated ceramic adsorber pucks. However, these pucks and its additional complex mounting hardware requirements result in several disadvantages, such as size, weight, and cost related concerns, that impact the spacecraft design and the integration and test schedule. As a result, a new innovative molecular adsorber coating was developed as a sprayable alternative to mitigate the risk of on-orbit molecular contamination. In this study, the formulation for molecular adsorber coatings was optimized using various binders, pigment treatment methods, binder to pigment ratios, thicknesses, and spray application techniques. The formulations that passed coating adhesion and vacuum thermal cycling tests were further tested for its adsorptive capacity. Accelerated molecular capacitance tests were performed in an innovatively designed multi-unit system containing idealized contaminant sources. This novel system significantly increased the productivity of the testing phase for the various formulations that were developed. Work performed during the development and testing phases has demonstrated successful application of molecular adsorber coatings onto metallic substrates, as well as, very promising results for the adhesion performance and the molecular capacitance of the coating. Continued testing will assist in the qualification of molecular adsorber coatings for use on future contamination sensitive spaceflight missions.

  14. RIMPAC 08: Naval Oceanographic Office glider operations

    NASA Astrophysics Data System (ADS)

    Mahoney, Kevin L.; Grembowicz, Ken; Bricker, Bruce; Crossland, Steve; Bryant, Danielle; Torres, Marc; Giddings, Tom

    2009-05-01

    The Naval Oceanographic Office (NAVOCEANO) Glider Operations Center (GOC) supported its first joint-mission exercise during Rim of the Pacific (RIMPAC) 08, a multi-national naval exercise conducted during July 2008 near the Hawaiian Islands. NAVOCEANO personnel deployed four Seagliders from USNS SUMNER for Anti-submarine Warfare (ASW) operations and four Slocum gliders for Mine Warfare (MIW) operations. Each Seaglider was equipped with a Sea-Bird Electronics (SBE) 41cp CTD and Wet Labs, Inc. bb2fl ECO-puck optical sensor. The instrumentation suite on the Slocum gliders varied, but each Slocum glider had an SBE 41cp CTD combined with one of the following optical sensors: a Wet Labs, Inc. AUVb scattering sensor, a Wet Labs, Inc. bb3slo ECO-puck backscattering sensor, or a Satlantic, Inc. OCR radiometer. Using Iridium communications, the GOC had command and control of all eight gliders, with Department of Defense (DoD) personnel and DoD contractors serving as glider pilots. Raw glider data were transmitted each time a glider surfaced, and the subsequent data flow included processing, quality-control procedures, and the generation of operational and tactical products. The raw glider data were also sent to the Naval Research Laboratory at Stennis Space Center (NRLSSC) for fusion with satellite data and modeled data (currents, tides, etc.) to create optical forecasting, optical volume, and electro-optical identification (EOID) performance surface products. The glider-based products were delivered to the ASW and MIW Reach Back Cells for incorporation into METOC products and for dissemination to the Fleet. Based on the metrics presented in this paper, the inaugural joint-mission operation was a success.

  15. Applied velocity versus offset (VVO) to validated & characterized fracturing zone in intra Baturaja Formation, South Sumatera Basin

    NASA Astrophysics Data System (ADS)

    Mardiyan, Hilman; Rusli, Saifatur

    2016-01-01

    The velocity versus offset (VVO) as new geophysical method can be applied to detect some geological phenomenon, such as hydrocarbon trap, structural-fracture anomaly, facies changes, etc. The VVO method is data driven, based on the normal move out equation (NMO) and measuring the local event correlation between adjacent traces to get velocity gradient attributes which is derived from cross-plotting the velocity versus offset (VVO). This paper is describing applied VVO model that controlled by well data which indicated fracture from logs data, especially Resistivity Imager Logs or Formation Micro Imager (FMI). Images FMI logs data at Intra-Baturaja Carbonate Formation (BRF) in South Palembang Sub-basin (SPB), South Sumatera, shows vugs with fractures which orientation is roughly NNW-SSE. Meanwhile, the 2D NMO seismic gathers indicated those all as hockey stick at far offset. By applying VVO method, hockey stick can be identified and then used to validated, characterized and localized where the fracturing zone in intra-Baturaja Formation is. Laterally, VVO quantified as velocity gradient attribute which associated with geological model as the fracturing zone in study area. Characterization fracturing zone in Intra Baturaja Formation as geological lateral model by design is a challenging task for most exploration and production. In term of exploration where limited data is available, it can be used step ahead as carbonate fracture reservoir candidate in proven area and adjacent, especially in SPB South Sumatra.

  16. Physiological responses to emotional excitement in healthy subjects and patients with coronary artery disease.

    PubMed

    Piira, Olli-Pekka; Miettinen, Johanna A; Hautala, Arto J; Huikuri, Heikki V; Tulppo, Mikko P

    2013-10-01

    Emotional excitement may trigger cardiovascular (CV) events, particularly in patients with coronary artery disease (CAD). Our aim was to compare changes in various biomarkers in CAD patients and age-matched healthy male subjects during "real-life" emotional excitement. Enthusiastic male ice hockey spectators (CAD n = 18, healthy subjects n = 16) attended Finnish national ice hockey play-off matches. Heart rate variability, plasma catecholamines, endothelin-1 (ET-1) and interleukin-6 (IL-6) were determined at the baseline and during the match. A significantly more marked increase in both ET-1 and IL-6 was observed in CAD patients compared with healthy subjects during the match (time group interaction p = 0.009 and p = 0.018 for ET-1 and IL-6, respectively). The high-frequency power of R-R intervals decreased in CAD patients (p<0.001) but did not change in healthy subjects (p = ns, time group interaction p<0.001). Changes in adrenaline and noradrenaline did not differ between the groups. Emotional excitement causes more marked increases of markers of vasoconstriction and acute inflammation and withdrawal of cardiac vagal regulation in patients with CAD. PMID:23916871

  17. Seismic refraction and GPR measurements of depth to bedrock: A case study from Randolph College, Virginia

    NASA Astrophysics Data System (ADS)

    Datta, A.; Pokharel, R.; Toteva, T.

    2007-12-01

    Randolph College is located in Lynchburg, VA, in the eastern edge of the Blue Ridge Mountains. Lynchburg city lies in the James River Synclinorium and consists of metasedimentary and metaigneous rocks. As part of College's plan to expand, a new soccer field will be build. For that purpose, part of a hill has to be excavated. Information was needed on the depth to the bedrock at the site. We conducted a seismic refraction experiment as part of an eight week summer research program for undergraduate students. We used 24 vertical geophones, spaced at 1.5 m interval. Our recording device was a 12 channel Geometrics geode (ES 3000). The source was an 8 pound sledge hummer. Source positions were chosen to be at 5, 10, 15 and 20 m on both sides of the array. We collected data along a tree line (in two segments) and across a hockey field. The data collected from the hockey field had very low signal to noise ratio and clear refraction arrivals. The other two acquisition lines were much noisier and difficult to interpret. Our results are consistent with data from seven bore holes in close proximity to the field site. We interpreted depth to bedrock to be between 4 and 12 m. The bedrock velocities are consistent with weathered gneiss. To improve the interpretation of the tree line records, we conducted a GPR survey. The preliminary radar images are showing highly heterogeneous subsurface with multiple point reflectors.

  18. Harnessing sloshing as a passive dampener

    NASA Astrophysics Data System (ADS)

    Killian, Taylor; Klaus, Robert; Truscott, Tadd

    2011-11-01

    This study investigates the impact dynamics of hollow elastic spheres partially filled with fluid, similar to roller hockey balls. Unlike an empty elastic ball, the fluid mitigates some of the rebound through an impulse driven exchange of energy wherein the fluid is forced into a jet inside the ball. Images gathered through experimentation show that the fluid reacts more quickly to the impact than the ball, which decouples the two masses (fluid and ball), imparts energy to the fluid, and removes rebound energy from the ball. The experimental results are compared to an energy method where energy is transferred from the external motion of the ball, to the internal flow of the fluid. Results suggest that while the internal liquid affects the fluid motion, the rebound characteristics of the ball are uniform for a given amount of fluid. Implications of this work on an analog to the roller hockey ball is a potential use of similar passive dampening systems in sports technology and marine engineering. BYU ORCA.

  19. Academic characteristics of orthopedic team physicians affiliated with high school, collegiate, and professional teams.

    PubMed

    Makhni, Eric C; Buza, John A; Byram, Ian; Ahmad, Christopher S

    2015-11-01

    We conducted a study to determine the academic involvement and research productivity of orthopedic team physicians at high school, college, and professional levels of sport. Through Internet and telephone queries, we identified 1054 team physicians from 362 institutions, including 120 randomly selected high schools and colleges and 122 professional teams (baseball, basketball, football, hockey). For all physicians included in the study, we performed a comprehensive search of the Internet and of a citation database to determine academic affiliations, number of publications, and h-index values. Of the 1054 physicians, 678 (64%) were orthopedic surgeons. Percentage of orthopedic team physicians affiliated with an academic medical center was highest in professional sports (64%; 173/270) followed by collegiate sports (36%; 98/275) and high school sports (20%; 27/133). Median number of publications per orthopedic team physician was significantly higher in professional sports (30.6) than in collegiate sports (10.7) or high school sports (6). Median number of publications by orthopedic physicians also varied by sport, with the highest number in Major League Baseball (37.9; range, 0-225) followed by the National Basketball Association (32.0; range, 0-227) and the National Football League (30.4; range, 0-460), with the lowest number within the National Hockey League (20.7; range, 0-144). Academic affiliation and research productivity of orthopedic team physicians vary by competition level and professional sporting league. PMID:26566551

  20. Born at the Wrong Time: Selection Bias in the NHL Draft

    PubMed Central

    Deaner, Robert O.; Lowen, Aaron; Cobley, Stephen

    2013-01-01

    Relative age effects (RAEs) occur when those who are relatively older for their age group are more likely to succeed. RAEs occur reliably in some educational and athletic contexts, yet the causal mechanisms remain unclear. Here we provide the first direct test of one mechanism, selection bias, which can be defined as evaluators granting fewer opportunities to relatively younger individuals than is warranted by their latent ability. Because RAEs are well-established in hockey, we analyzed National Hockey League (NHL) drafts from 1980 to 2006. Compared to those born in the first quarter (i.e., JanuaryMarch), those born in the third and fourth quarters were drafted more than 40 slots later than their productivity warranted, and they were roughly twice as likely to reach career benchmarks, such as 400 games played or 200 points scored. This selection bias in drafting did not decrease over time, apparently continues to occur, and reduces the playing opportunities of relatively younger players. This bias is remarkable because it is exhibited by professional decision makers evaluating adults in a context where RAEs have been widely publicized. Thus, selection bias based on relative age may be pervasive. PMID:23460902

  1. Epidemiology, pathomechanics, and prevention of athletic injuries to the cervical spine.

    PubMed

    Torg, J S

    1985-06-01

    Athletic injuries to the cervical spine associated with quadriplegia most commonly occur as a result of axial loading. Whether it be a football player striking an opponent with the top or crown of his helmet, a poorly executed dive into a shallow body of water where the subject strikes his head on the bottom, or a hockey player pushed into the boards head first, the fragile cervical spine is compressed between the rapidly decelerated head and the continued momentum of the body. Appropriate rule changes recognizing this mechanism have resulted in a reduction of football quadriplegia by two-thirds. Presumably, educational efforts designed to inform the public of the dangers of diving would have a similar effect. The predominance of the axial loading mechanism is not as clearly defined in trampoline and minitrampoline injuries. However, both of these devices are dangerous when used in the best of circumstances, and their use has no place in recreational, educational, or competitive gymnastics. The emergence of severe cervical spine injuries resulting from ice hockey is recognized. Methods, based on sound scientific evidence, to modify the games so as to prevent these injuries are lacking. PMID:3894866

  2. Preventing head and neck injury.

    PubMed

    McIntosh, A S; McCrory, P

    2005-06-01

    A wide range of head and neck injury risks are present in sport, including catastrophic injury. The literature since 1980 on prevention of head and neck injury in sport was reviewed, focusing on catastrophic and brain injury and identifying the range of injury prevention methods in use. There have been few formal evaluations of injury prevention methods. Approaches that are considered, or have been proven, to be successful in preventing injury include: modification of the baseball; implementation of helmet standards in ice hockey and American football and increased wearing rates; use of full faceguards in ice hockey; changes in rules associated with body contact; implementation of rules to reduce the impact forces in rugby scrums. Helmets and other devices have been shown to reduce the risk of severe head and facial injury, but current designs appear to make little difference to rates of concussion. Research methods involving epidemiological, medical, and human factors are required in combination with biomechanical and technological approaches to reduce further injury risks in sport. PMID:15911597

  3. Meeting People Where They Are: Connecting Climate Change Impacts with the Interests of Particular Communities

    NASA Astrophysics Data System (ADS)

    Wake, C. P.; Rogers, W. C.

    2011-12-01

    Several recent surveys (e.g., Brookings, Pew, Yale Project on Climate Change) have shown that a significant portion of Americans do not believe that human's are causing our climate to change, and that this portion has increased over the past 3 years. While there are a variety of reasons for this increase, it is clear that we need to develop new approaches that translate into more effective outreach activities on the issue of climate change for individuals and groups who are either "on the fence" or do not believe in global warming. One proven method to improve the effectiveness and develop new approaches to outreach efforts is for scientists to partner with external organizations who have expertise in communications. As an example, we describe a long-standing partnership that developed a video aimed at a particular community (people who play pond hockey) that connected their particular passion for pond hockey with the broader issue of regional climate change, warmer winters, earlier ice-out dates, and what it means to be from New England. We suggest that framing outreach efforts around what people and communities are interested in, as opposed to what scientists want to talk about, will be more effective at generating interest in the climate change issue among those non-believers.

  4. Obtaining oblique technique source-to-skin distances for irregular field (Clarkson) calculations: The Mayo Off-axis Distance Indicator

    SciTech Connect

    Lajoie, W.N. )

    1988-09-01

    Significant dose inhomogeneities may exist between the supraclavicular fossa (SCF) and the internal mammary chain (IMC) regions in the irregular L-shaped (hockey stick) field associated with breast cancer treatments. This dose inhomogeneity exists, in part, because of a positive air gap in the SCF and a negative air gap in the IMC locations. Independent of treatment technique, (i.e., whether anterior-posterior (AP) or oblique fields are used), accurate source-to-skin distance (SSD) values for the SCF, IMC, and axilla are necessary when doing an irregular field (Clarkson) dose calculation. However, when an oblique technique is used to treat the hockey stick field, obtaining non-central-axis SSDs is not as straightforward as when an AP technique is employed. The Mayo Off-axis Distance Indicator was constructed to slide into the blocking tray slot of the simulator or treatment machine. This mechanical measuring device provides quick and accurate SSD measurements for non-central-axis points under either AP or, more importantly, oblique treatment conditions.

  5. Threshold effect in lead-induced peripheral neuropathy

    SciTech Connect

    Schwartz, J.; Landrigan, P.J.; Feldman, R.G.; Silbergeld, E.K.; Baker, E.L. Jr.; von Lindern, I.H.

    1988-01-01

    We previously demonstrated a negative correlation between blood lead level and motor nerve conduction velocity in 202 asymptomatic 5 to 9-year-old children living near a lead smelter in Idaho. Blood lead levels ranged from 13 to 97 micrograms/dL. To determine whether a threshold exists between blood lead level and maximal motor nerve conduction velocity, we conducted three regression analyses on these data: a ''hockey stick'' regression, a logistic regression, and a quadratic regression. We found evidence for a threshold in all three analyses: at a blood level of 30 micrograms/dL in the ''hockey stick'' regression, at 20 micrograms/dL in the logistic, and at 25 to 30 micrograms/dL in the quadratic. Neither age, sex, socioeconomic status, nor duration of residence near the smelter significantly modified the relationship. These analyses confirm that asymptomatic increased lead absorption causes slowing of nerve conduction, but they also indicate that measurement of maximal motor nerve conduction velocity is an insensitive screen for low-level lead toxicity.

  6. Effect of the coefficient of friction of a running surface on sprint time in a sled-towing exercise.

    PubMed

    Linthorne, Nicholas P; Cooper, James E

    2013-06-01

    This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (micro = 0.21-0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient offriction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected. PMID:23898689

  7. The effect of leg preference on postural stability in healthy athletes.

    PubMed

    Huurnink, Arnold; Fransz, Duncan P; Kingma, Idsart; Hupperets, Maarten D W; van Dieën, Jaap H

    2014-01-01

    In research regarding postural stability, leg preference is often tested and controlled for. However, leg preference may vary between tasks. As athletes are a group of interest for postural stability testing, we evaluated the effect of five leg preference tasks categorization (step up, hop, ball kick, balance, pick up) on single-leg postural stability of 16 field hockey athletes. The 'center of pressure speed' was calculated as the primary outcome variable of single-leg postural stability. Secondary variables were 'mean length of the GRF vector in the horizontal plane', 'mean length of the ankle angular velocity vector', and 'mean length of the hip angular velocity vector', as well as the separate outcomes per degree of freedom. Results showed that leg preference was inconsistent between leg preference tasks. Moreover, the primary and secondary variables yielded no significant difference between the preferred and non-preferred legs, regardless of the applied leg preference task categorization (p>0.05). The present findings do not support the usability of leg preference tasks in controlling for bias of postural stability. In conclusion, none of the applied leg preference tasks revealed a significant effect on postural stability in healthy field hockey athletes. PMID:24239407

  8. Mandatory mouthguard rules for high school athletes in the United States.

    PubMed

    Mills, Stephen C

    2015-01-01

    High school athletes seem particularly predisposed to dental injury, but athletic mouthguards have an excellent track record of success in reducing the severity and incidence of dental injuries in sports. Therefore, it has been suggested that mouthguards be made mandatory for high school athletes who participate in sports with risk of injury. The National Federation of State High School Associations currently recommends that mouthguards be mandated for high school football, lacrosse, ice hockey, and field hockey players as well as for wrestlers who are wearing orthodontic appliances. Different states have tried to mandate additional sports with varying degrees of success. This article summarizes the process that leads to rule changes for high school athletes at the national level and discusses the history of 4 states-Minnesota, Maine, New Hampshire, and Massachusetts-that have tried to mandate mouthguards for different sports. Common complaints that lead to the cessation of mouthguard rules, such as speech considerations, breathing ability, and cleanliness, are discussed. PMID:26545273

  9. Diminished acquired equivalence yet good discrimination performance in older participants

    PubMed Central

    Robinson, Jasper; Owens, Emma

    2013-01-01

    We asked younger and older human participants to perform computer-based configural discriminations that were designed to detect acquired equivalence. Both groups solved the discriminations but only the younger participants demonstrated acquired equivalence. The discriminations involved learning the preferences [like (+) or dislike (?)] for sports [e.g., tennis (t) and hockey (h)] of four fictitious people [e.g., Alice (A), Beth (B), Charlotte (C), and Dorothy (D)]. In one experiment, the discrimination had the form: At+, Bt?, Ct+, Dt?, Ah?, Bh+, Ch?, Dh+. Notice that, e.g., Alice and Charlotte are equivalent in liking tennis but disliking hockey. Acquired equivalence was assessed in ancillary components of the discrimination (e.g., by looking at the subsequent rate of whole versus partial reversal learning). Acquired equivalence is anticipated by a network whose hidden units are shared when inputs (e.g., A and C) signal the same outcome (e.g., +) when accompanied by the same input (t). One interpretation of these results is that there are age-related differences in the mechanisms of configural acquired equivalence. PMID:24130542

  10. Competitive Sport Involvement and Substance Use among Adolescents: A Nationwide Study

    PubMed Central

    Veliz, Philip Todd; Boyd, Carol J.; McCabe, Sean Esteban

    2015-01-01

    Background The empirical research examining the impact of sports participation on alcohol and other drug use has produced mixed results. Part of this problem may be the result of how different types of sports participation create different experiences that shape certain types of behaviors that either facilitate or deter substance use. Objectives We examined the association between different types of competitive sports participation and substance use among a nationally representative sample of adolescents. Methods Two recent cross-sections from the Monitoring the Future were merged to capture a large subsection of adolescents who participate in either high-contact sports (football, wrestling, hockey and lacrosse), semi-contact sports (baseball, basketball, field hockey and soccer), and non-contact sports (cross-country, gymnastics, swimming, tennis, track, and volleyball). Results Multivariate analyses revealed that adolescents who participated in high-contact sports had higher odds of using substances during the past 30 days and initiating substance use at early ages. Further, adolescents who participated in non-contact sports had lower odds to indicate smoking cigarettes and marijuana during the past 30 days. Conclusions Parents, educators, and policy makers need to consider that some sporting contexts may be a catalyst to engage in risky behaviors like substance use. PMID:25290659

  11. Atmospheric dispersion modeling for the worst-case detonation accident at the proposed Advanced Hydrotest Facility

    SciTech Connect

    Bowen, B.M., LLNL

    1996-10-01

    The Atmospheric Release Advisory Capability (ARAC) was requested to estimate credible worst-case dose, air concentration, and deposition of airborne hazardous materials that would result from a worst-case detonation accident at the proposed Advanced Hydrotest Facility (AHT) at the Nevada Test Site (NTS). Consequences were estimated at the closest onsite facility, the Device Assembly Facility (DOFF), and offsite location (intersection of Highway and U.S. 95). The materials considered in this analysis were weapon-grade plutonium, beryllium, and hydrogen fluoride which is a combustion product whose concentration is dependent upon the quantity of high explosives. The analysis compares the calculated results with action guidelines published by the Department of Defense in DoD 5100.52-M (Nuclear Weapon Accident Response Procedures). Results indicate that based on a one kg release of plutonium the whole body radiation dose could be as high as 3 Rem at the DOFF. This level approaches the 5 Rem level for which the Department of Defense requires respiratory protection, recommends sheltering and the consideration of evacuation. Deposition levels at the DOFF could approach 6 uCi/m{sup 2} for which the Department of Defense recommends access on a need-only basis and suggests that a possible controlled evacuation might be required. For a one kg release of plutonium, the dose at the nearest off-site location could reach 0.5. At this level, the Department of Defense suggests that sheltering be considered. For a one kg release of beryllium, the peak 5-minute concentration at the DOFF could be as as 20% of 6xlO{sup -3} mg/m{sup 2} which is the applicable by Response Planning Guideline (ERPG-1). At the nearest offsite location, the beryllium concentrations from a one kg release would be two orders of magnitude less than the same guideline. For the detonation of 100 kg of the explosive LX-17, the concentration of hydrogen fluoride at both the DOFF and the nearest offsite location would be four orders of magnitude less than the lowest applicable Emergency Response Planning Guideline (ERPG-1). The calculations and analysis reported here indicate that emergency response planning for such an accident at the present proposed location of the ABF should include provisions for the protection of personnel located at the DOFF and their possible evacuation.

  12. Recent advances in the molten salt destruction of energetic materials

    SciTech Connect

    Pruneda, C. O., LLNL

    1996-09-01

    We have demonstrated the use of the Molten Salt Destruction (MSD) Process for destroying explosives, liquid gun propellant, and explosives-contaminated materials on a 1.5 kg of explosive/hr bench- scale unit (1, 2, 3, 4, 5). In our recently constructed 5 kg/hr pilot- scale unit we have also demonstrated the destruction of a liquid gun propellant and simulated wastes containing HMX (octogen). MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen, and water. Any inorganic constituents of the waste, such as metallic particles, are retained in the molten salt. The destruction of energetic materials waste is accomplished by introducing it, together with air, into a vessel containing molten salt (a eutectic mixture of sodium, potassium, and lithium carbonates). The following pure explosives have been destroyed in our bench-scale experimental unit located at Lawrence Livermore National Laboratory`s (LLNL) High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K- 6 (keto-RDX), NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following compositions were also destroyed: Comp B, LX- IO, LX- 1 6, LX- 17, PBX-9404, and XM46 (liquid gun propellant). In this 1.5 kg/hr bench-scale unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NO{sub x} were found to be well below 1%. In addition to destroying explosive powders and compositions we have also destroyed materials that are typical of residues which result from explosives operations. These include shavings from machined pressed parts of plastic-bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the process data obtained on the bench-scale unit we designed and constructed a next-generation 5 kg/hr pilot-scale unit, incorporating LLNL`s advanced chimney design. The pilot unit has completed process implementation operations and explosives safety reviews. To date, in this pilot unit we have successfully destroyed liquid gun propellant and dimethylsulfoxide containing HMX in continuous, long-duration runs.

  13. A Study of Detonation Diffraction in the Ignition-and-Growth Model

    SciTech Connect

    Kapila, A K; Schwendeman, D W; Bdzil, J B; Henshaw, W D

    2006-04-14

    Heterogeneous high-energy explosives are morphologically, mechanically and chemically complex. As such, their ab-initio modeling, in which well-characterized phenomena at the scale of the microstructure lead to a rationally homogenized description at the scale of observation, is a subject of active research but not yet a reality. An alternative approach is to construct phenomenological models, in which forms of constitutive behavior are postulated with an eye on the perceived picture of the micro-scale phenomena, and which are strongly linked to experimental calibration. Most prominent among these is the ignition-and-growth model conceived by Lee and Tarver. The model treats the explosive as a homogeneous mixture of two distinct constituents, the unreacted explosive and the products of reaction. To each constituent is assigned an equation of state, and a single reaction-rate law is prescribed for the conversion of the explosive to products. It is assumed that the two constituents are always in pressure and temperature equilibrium. The purpose of this paper is to investigate in detail the behavior of the model in situations where a detonation turns a corner and undergoes diffraction. A set of parameters appropriate for the explosive LX-17 is selected. The model is first examined analytically for steady, planar, 1-D solutions and the reaction-zone structure of Chapman-Jouguet detonations is determined. A computational study of two classes of problems is then undertaken. The first class corresponds to planar, 1-D initiation by an impact, and the second to corner turning and diffraction in planar and axisymmetric geometries. The 1-D initiation, although interesting in its own right, is utilized here as a means for interpretation of the 2-D results. It is found that there are two generic ways in which 1-D detonations are initiated in the model, and that these scenarios play a part in the post-diffraction evolution as well. For the parameter set under study the model shows detonation failure, but only locally and temporarily, and does not generate sustained dead zones. The computations employ adaptive mesh refinement and are finely resolved. Results are obtained for a rigid confinement of the explosive. Compliant confinement represents its own computational challenges and is currently under study. Also under development is an extended ignition-and-growth model which takes into account observed desensitization of heterogeneous explosives by weak shocks.

  14. An investigation of the effects of sports-related concussion in youth using functional magnetic resonance imaging and the head impact telemetry system.

    PubMed

    Keightley, Michelle; Green, Stephanie; Reed, Nick; Agnihotri, Sabrina; Wilkinson, Amy; Lobaugh, Nancy

    2011-01-01

    One of the most commonly reported injuries in children who participate in sports is concussion or mild traumatic brain injury (mTBI). Children and youth involved in organized sports such as competitive hockey are nearly six times more likely to suffer a severe concussion compared to children involved in other leisure physical activities. While the most common cognitive sequelae of mTBI appear similar for children and adults, the recovery profile and breadth of consequences in children remains largely unknown, as does the influence of pre-injury characteristics (e.g. gender) and injury details (e.g. magnitude and direction of impact) on long-term outcomes. Competitive sports, such as hockey, allow the rare opportunity to utilize a pre-post design to obtain pre-injury data before concussion occurs on youth characteristics and functioning and to relate this to outcome following injury. Our primary goals are to refine pediatric concussion diagnosis and management based on research evidence that is specific to children and youth. To do this we use new, multi-modal and integrative approaches that will: 1. Evaluate the immediate effects of head trauma in youth. 2. Monitor the resolution of post-concussion symptoms (PCS) and cognitive performance during recovery. 3. Utilize new methods to verify brain injury and recovery. To achieve our goals, we have implemented the Head Impact Telemetry (HIT) System. (Simbex; Lebanon, NH, USA). This system equips commercially available Easton S9 hockey helmets (Easton-Bell Sports; Van Nuys, CA, USA) with single-axis accelerometers designed to measure real-time head accelerations during contact sport participation. By using telemetric technology, the magnitude of acceleration and location of all head impacts during sport participation can be objectively detected and recorded. We also use functional magnetic resonance imaging (fMRI) to localize and assess changes in neural activity specifically in the medial temporal and frontal lobes during the performance of cognitive tasks, since those are the cerebral regions most sensitive to concussive head injury. Finally, we are acquiring structural imaging data sensitive to damage in brain white matter. PMID:21248710

  15. Final Report on Initial Samples Supplied by LLNL for Task 3.3 Binder Burnout and Sintering Schedule Optimisation

    SciTech Connect

    Walls, P

    1999-01-04

    Sixteen of the twenty-one samples have been investigated using the scanning laser dilatometer. This includes all three types of samples with different preparation routes and organic content. Cracks were observed in all samples, even those only heated to 300 C. It was concluded that the cracking was occurring in the early part of the heat treatment before the samples reached 300 C. Increase in the rate of dilation of the samples occurred above 170 C which coincided with the decomposition of the binder/wax additives as determined by differential thermal analysis. A comparison was made with SYNROC C material (Powder Run 143), samples of which had been CIPed and green machined to a similar diameter and thickness as the 089mm SRTC pucks. These samples contained neither binder nor other organic processing aids and had been kept in the same desiccator as the SRTC samples. The CIPed Synroc C samples sintered to high density with zero cracks. As the cracks made up only a small contribution to the change in diameter of the sample compared to the sintering shrinkage, useful information could still be gained from the runs. The sintering curves showed that there was much greater shrinkage of the Type III samples containing only the 5% PEG binder compared to the Type I which contained polyolefin wax as processing aid. Slight changes in gradient of the sintering curve were observed, however, due to the masking effect of the cracking, full analysis of the sintering kinetics cannot be conducted. Even heating the samples to 300 C at 1.0 or 0.5 C/min could not prevent crack formation. This indicated that heating rate was not the critical parameter causing cracking of the samples. Sectioning of green bodies revealed the inhomogeneous nature of the binder/lubricant distribution in the samples. Increased homogeneity would reduce the amount of binder/lubricant required, which should in turn, reduce the degree of cracking observed during heating to the binder burnout temperature. A combination of: (1) use of a higher forming pressure, (2) reduction of organics content, (3) improvement in the distribution of the organic wax and binder components throughout the green body, could possibly alleviate cracking. Ultrasonic emulsification of the binder and wax with a small quantity of water prior to adding to the ball or attrition mill is advised to ensure more even distribution of the wax/binder system. This would also reduce the proportion of organic additives required. The binder burnout stage of the operation must first be optimized (i.e. production of pucks with no cracks) prior to optimization of the sintering stage.

  16. Possible disease transmission by contaminated mouthguards in two young football players.

    PubMed

    Glass, R Thomas; Wood, C Rieger; Bullard, James W; Conrad, Robert S

    2007-01-01

    Previous studies have demonstrated that athletic mouthguards worn by ice hockey and football players harbor large numbers of bacteria, yeasts, and molds, some of which are either opportunistic or frank pathogens. This article details the clinical history of two junior high school football players. The first player had cellulitis of the leg after a non-break injury. The same unusual bacterium was isolated from both the athletic mouthguard and abscess cultures from the wound. The second patient suffered an attack of exercise-induced asthma so severe that his inhaler could not control the symptoms enough for him to resume play. This child's mouthguard was contaminated with five different species of mold. The clinical implications of mouthguard contamination, possible avenues of disease transmission, and recommendations for mouthguard care are discussed. PMID:17899722

  17. Relative age effect revisited: findings from the dance domain.

    PubMed

    van Rossum, Jacques H A

    2006-04-01

    The relative age effect is a worldwide phenomenon. While there is solid empirical evidence for the existence in sports like soccer and ice hockey, there are also some findings indicating the absence of the phenomenon. In an earlier study, no support was found with Dutch top-level athletes in table tennis and in volleyball. The explanation was that in athletic tasks which depend heavily on the technical ability (or motor skill) of the participant, a relative age effect will not be observed. In the present study this supposition was tested again with three samples of Dutch preprofessional dance students (overall number of subjects: 546). Again no support was obtained for the relative age effect. Therefore, a case is being built that the relative age effect is not an omnipresent phenomenon. PMID:16826648

  18. Prevention of catastrophic injuries in sports.

    PubMed

    Boden, Barry P

    2007-01-01

    Catastrophic sports injuries are rare but severely debilitating events. Catastrophic injuries are divided into two etiologic categories: direct and indirect. Direct injuries are those resulting directly from participation in a sport, such as a collision in football. Football is associated with the greatest number of direct catastrophic injuries for all major team sports in the United States, whereas ice hockey, pole vaulting, gymnastics, and football have the highest incidence of direct catastrophic injuries per 100,000 male participants. Cheerleading is associated with the highest number of direct catastrophic injuries for all sports in which females participate. Indirect or nontraumatic injuries are caused by systemic failure resulting from exertion while participating in a sport and include cardiovascular conditions, heat illness, exertional hyponatremia, and dehydration. Indirect deaths in athletes are predominantly caused by cardiovascular conditions such as hypertrophic cardiomyopathy and coronary artery disease. PMID:17472322

  19. Direct catastrophic injury in sports.

    PubMed

    Boden, Barry P

    2005-11-01

    Catastrophic sports injuries are rare but tragic events. Direct (traumatic) catastrophic injury results from participating in the skills of a sport, such as a collision in football. Football is associated with the greatest number of direct catastrophic injuries for all major team sports in the United States. Pole vaulting, gymnastics, ice hockey, and football have the highest incidence of direct catastrophic injuries for sports in which males participate. In most sports, the rate of catastrophic injury is higher at the collegiate than at the high school level. Cheerleading is associated with the highest number of direct catastrophic injuries for all sports in which females participate. Indirect (nontraumatic) injury is caused by systemic failure as a result of exertion while participating in a sport. Cardiovascular conditions, heat illness, exertional hyponatremia, and dehydration can cause indirect catastrophic injury. Understanding the common mechanisms of injury and prevention strategies for direct catastrophic injuries is critical in caring for athletes. PMID:16272269

  20. Frequency and predictability of sports injuries in intercollegiate athletes.

    PubMed

    Meeuwisse, W H; Fowler, P J

    1988-03-01

    This study analyzes injury frequency and predictability in 712 intercollegiate athletes in 24 different male and female sports over the 1984-85 season. The injury rate was 38% for males and 32% for females, with the males suffering more acute injuries. While the men's hockey team had the highest player injury rate, the football team had the greatest absolute number of injuries. Overall, the anatomic location with the highest injury rate was the knee, while sprains were the most common type of injury. Further elaboration of these results are provided in graphic form. By comparing injury occurrence to past history and preparticipation physical findings, this study assesses the predictability of injury. With one exception, no significant relationship was found. It would appear that the preseason exam may play a role in identification, rather than prediction of sports injuries. PMID:3359359