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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. Puck collisions

    NASA Astrophysics Data System (ADS)

    Hauge, E. H.

    2012-09-01

    Collisions between two ice hockey pucks sliding on frictionless ice are studied, with both inelasticity and frictional contact between the colliding surfaces of the two pucks taken into account. The latter couples translational and rotational motion. The full solution depends on the sign and magnitude of the initial mismatch between the surface velocities at the point of contact. The initial state defines two physically distinct regimes for the friction coefficient. To illustrate the complexities, we discuss at length the typical situation (well known from curling) when puck number 1 is initially at rest, and is hit by puck number 2 with an arbitrary impact parameter, velocity and angular velocity. We find that the total outgoing angle between the pucks exceeds \\frac{1}{2}\\pi if and only if the collision leads to a net increase in the translational part of the kinetic energy. The conditions for this to happen are scrutinized, and the results are presented both analytically and numerically by a set of representative curves. This paper is written with an ambitious undergraduate, and her teacher, in mind.

  5. 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.

  6. Evaluation of LX-17 made from water-aminated TATB

    SciTech Connect

    Osborn, A.G.

    1982-10-01

    Water-aminated TATB was formulated into LX-17 at both Pantex and Holston. Mechanical properties, growth, pressed density, corner turning and gap sensitivity properties were compared. Mechanical properties, corner turning and gap sensitivity were similar to those of LX-17 made from dry-aminated TATB. Permanent expansion resulting from thermal aging may be slightly greater than that of LX-17 with dry-aminated TATB.

  7. LX-17-1 Stockpile Returned Material Lot Comparison

    SciTech Connect

    Gagliardi, F.; Pease, S.; Willey, T.

    2015-02-18

    Many different lots of LX-17 have been produced over the years. Two varieties of LX-17, LX-17-0 and LX-17-1, have at one point or another been a part of the Livermore stockpile systems. LX-17-0 was made with dry-aminated TATB whereas LX-17-1 was made with wet-aminated TATB. Both versions have the same TATB to Kel-F 800 mass ratio of 92.5%/7.5%. Both kinds of LX-17 were formulated at Holston during the late 1970s or early to mid-1980s and were certified to have met the necessary specifications that cover the purity, particle size range, explosive to binder ratio, etc. In recent years, Trevor Willy and others have performed a detailed evaluation of solid parts made from each of the LX-17 lots manufactured at Holston. Using the Advanced Light Source at LBNL, Willey and his colleagues radiographed many samples from isostatic pressings using the same scanning conditions. In their investigation they identified that even though the bulk composition can be the same, there may exist a large spread in how smoothly the TATB and binder were distributed within the radiographed volume of different lots of material.1 Overall, the dry-aminated TATB-based material, LX-17-0, had a smooth TATB and binder distribution, whereas the wet-aminated TATB-based LX-17-1 showed a wide range of binder distributions. The results for five different LX-17-1 lots are shown in Figure 1. The wide variation in material distribution has raised the question about whether or not this sort variability will cause significant differences in mechanical behavior.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  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. 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.

  2. 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.

  3. 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.

  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; 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.

  5. 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.

  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. End-Effector Development for the PIP Puck Handling Robot

    SciTech Connect

    Fowley, M.D.

    2001-01-03

    It has been decided that excess, weapons-grade plutonium shall be immobilized to prevent nuclear proliferation. The method of immobilization is to encapsulate the plutonium in a ceramic puck, roughly the size of a hockey puck, using a sintering process. This method has been officially identified as the Plutonium Immobilization Process (PIP). A Can-in-Canister storage method will be used to further immobilize the plutonium. The Can-in-Canister method uses the existing design of a Defense Waste Processing Facility (DWPF) canister to house the plutonium pucks. the process begins with several pucks being stacked in a stainless steel can. Several of the stainless steel cans are stacked in a cage-like magazine. Several of the magazines are then placed in a DWPF canister. The DWPF canister is then filled with molten glass containing high-level, radioactive waste from the DWPF vitrification process. The Can-in-Canister method makes reclamation of plutonium from the pucks technically difficult and highly undesirable. The mechanical requirements of the Can-in-Canister process, in conjunction with the amount of time required to immobilize the vast quantities of weapons-grade plutonium, will expose personnel to unnecessarily high levels of radiation if the processes were completed manually, in glove boxes. Therefore, automated equipment is designed into the process to reduce or eliminate personnel exposure. Robots are used whenever the automated handling operations become complicated. There are two such operations in the initial stages of the Can-in-Canister process, which required a six-axis robot. The first operation is a press unloading process. The second operation is a tray transfer process. To successfully accomplish the operational tasks described in the two operations, the end-effector of the robot must be versatile, lightweight, and rugged. As a result of these demands, an extensive development process was undertaken to design the optimum end-effector for these puck-handling operations. As an overall requirement, it was desired to keep the design of the robot end-effector as simple as possible. There were pros and cons for either type of actuation method (pneumatic or electric). But, pneumatic actuation was chosen for its simplicity and durability in a radioactive environment. It was determined early in the design process that at least two different types of end-effectors would be required for each of the operations. Therefore, a tool changer was incorporated into the end-effector design. The tool changer would also provide for simple end-effector maintenance when used in the PIP process.

  8. End-Effector Development for the PIP Puck Handling Robot

    SciTech Connect

    Fowley, M.D.

    2001-01-31

    It has been decided that excess, weapons-grade plutonium shall be immobilized to prevent nuclear proliferation. The method of immobilization is to encapsulate the plutonium in a ceramic puck, roughly the size of a hockey puck, using a sintering process. This method has been officially identified as the Plutonium Immobilization Process (PIP). A Can-in-Canister storage method will be used to further immobilize the plutonium. The Can-in-Canister method uses the existing design of a Defense Waste Processing Facility (DWPF) canister to house the plutonium pucks. the process begins with several pucks being stacked in a stainless steel can. Several of the stainless steel cans are stacked in a cage-like magazine. Several of the magazines are then placed in a DWPF canister. The DWPF canister is then filled with molten glass containing high-level, radioactive waste from the DWPF vitrification process. The Can-in-Canister method makes reclamation of plutonium from the pucks technically difficult and highly undesirable. The mechanical requirements of the Can-in-Canister process, in conjunction with the amount of time required to immobilize the vast quantities of weapons-grade plutonium, will expose personnel to unnecessarily high levels of radiation if the processes were completed manually, in glove boxes. Therefore, automated equipment is designed into the process to reduce or eliminate personnel exposure. Robots are used whenever the automated handling operations become complicated. There are two such operations in the initial stages of the Can-in-Canister process, which required a six-axis robot. The first operation is a press unloading process. The second operation is a tray transfer process. To successfully accomplish the operational tasks described in the two operations, the end-effector of the robot must be versatile, lightweight, and rugged. As a result of these demands, an extensive development process was undertaken to design the optimum end-effector for these puck-handling operations. As an overall requirement, it was desired to keep the design of the robot end-effector as simple as possible. There were pros and cons for either type of actuation method (pneumatic or electric). But, pneumatic actuation was chosen for its simplicity and durability in a radioactive environment. It was determined early in the design process that at least two different types of end-effectors would be required for each of the operations. Therefore, a tool changer was incorporated into the end-effector design. The tool changer would also provide for simple end-effector maintenance when used in the PIP process.

  9. 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

  10. 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…

  11. 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.

  12. APPLICATION OF THE EMBEDDED FIBER OPTIC PROBE IN HIGH EXPLOSIVE DETONATION STUDIES: PBX-9502 AND LX-17

    SciTech Connect

    Hare, D; Goosman, D; Lorenz, K; Lee, E

    2006-09-26

    The Embedded Fiber Optic probe directly measures detonation speed continuously in time, without the need to numerically differentiate data, and is a new tool for measuring time-dependent as well as steady detonation speed to high accuracy. It consists of a custom-design optical fiber probe embedded in high explosive. The explosive is detonated and a refractive index discontinuity is produced in the probe at the location of the detonation front by the compression of the detonation. Because this index-jump tracks the detonation front a measurement of the Doppler shift of laser light reflected from the jump makes it possible to continuously measure detonation velocity with high spatial and temporal resolution. We have employed this probe with a Fabry-Perot-type laser Doppler velocimetry system additionally equipped with a special filter for reducing the level of non-Doppler shifted light relative to the signal. This is necessary because the index-jump signal is relatively weak compared to the return expected from a well-prepared surface in the more traditional and familiar example of material interface velocimetry. Our observations were carried out on a number of explosives but this work is focused on our results on PBX-9502 (95% TATB, 5% Kel-F) and LX-17 (92.5% TATB, 7.5% Kel-F) at varying initial charge density. Our measurements reveal a density dependence significantly lower than previous quoted values and lower than theoretical calculations. Our limited data on detonation speed dependence on wave curvature is in reasonable agreement with previous work using more standard methods and confirms deviation from the Wood-Kirkwood theoretical formula.

  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. Physiology of ice hockey.

    PubMed

    Montgomery, D L

    1988-02-01

    Ice hockey is characterized by high intensity intermittent skating, rapid changes in velocity and duration, and frequent body contact. The typical player performs for 15 to 20 minutes of a 60-minute game. Each shift lasts from 30 to 80 seconds with 4 to 5 minutes of recovery between shifts. The intensity and duration of a particular shift determines the extent of the contribution from aerobic and anaerobic energy systems. The high intensity bursts require the hockey player to develop muscle strength, power, and anaerobic endurance. The length of the game and the need to recover quickly from each shift demands a good aerobic system. Physical characteristics of elite players show that defensemen are taller and heavier than forwards probably due to positional demands. Hockey players are mesomorphic in structure. They are relatively lean since excess mass is detrimental to their skating performance. There is a large interindividual variability in VO2 during skating. Both the aerobic and anaerobic energy systems are important during a hockey game. Peak heart rates during a shift on the ice exceed 90% of HRmax with average on-ice values of about 85% of HRmax. Blood lactate is elevated above resting values confirming the anaerobic nature of the game. Glycogen depletion studies show a preferential utilisation of glycogen from the slow twitch fibres but also significant depletion from the fast twitch fibres. Elite hockey players display a muscle fibre composition similar to untrained individuals. Physiological profiles of elite hockey teams reveal the importance of aerobic endurance, anaerobic power and endurance, muscular strength and skating speed. Training studies have attempted to improve specific components of hockey fitness. Using traditional laboratory tests, a season of hockey play shows gains in anaerobic endurance but no change in aerobic endurance. On-ice tests of hockey fitness have been recommended as an essential part of the hockey player's physiological profile. Existing training procedures may develop chronic muscular fatigue in hockey players. Lactic acidosis is associated with the onset and persistence of muscle fatigue. Muscle force output remains impaired throughout the hockey player's typical cycle of practices and games. A supplementary programme of low-intensity cycling during the competitive phase of training was unsuccessful in altering VO2max. Strength decrements during the hockey season are attributed to a lack of a specifically designed strength maintenance programmes. On-ice and off-ice training programmes should focus on the elevation of aerobic endurance, anaerobic power and endurance, muscular strength and skating speed. PMID:3281210

  15. 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.

  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. Remote handling in the Plutonium Immobilization Project: Puck packaging

    SciTech Connect

    Kriikku, E.

    1999-07-01

    The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP scope includes unloading transportation containers, preparing the feed streams, converting the metal feed to an oxide, adding the ceramic precursors, pressing the pucks, inspecting pucks, and sintering pucks. The PIP scope also includes loading the pucks into metal cans, sealing the cans, inspecting the cans, loading the cans into magazines, loading magazines into Defense Waste Processing Facility (DWPF) canisters, and transporting the canisters to the DWPF. The DWPF will fill the canister with a mixture of high-level waste and glass for permanent storage. Because of the radiation, remote equipment will perform PIP operations in a contained environment. The PIP puck packaging includes loading pucks into metal cans, sealing the cans, and inspecting the cans. A magnetically coupled elevator will lower a tray of pucks onto a magnetically coupled transport cart. This cart will carry the tray through an air lock into the can-loading glove box. Inside the glove box, a magnetically coupled tray lifter will raise the tray off the cart. A three-axis Cartesian robot will use a vacuum cup on a long pipe to lift the 67.3-mm (2.65-in.)-diam, 25.4-mm (1.0-in.)-tall pucks from the transfer tray and place 20 pucks in a 76.2-mm (3.0-in.)-diam stainless steel can. The Cartesian robot will place a custom hood on the open metal can, and this hood will remove the air from the can, insert helium, and place a hollow plug in the can. The SRS-developed bagless transfer system will weld the plug to the can wall and cut the can in the weld area. The can stub and the upper plug half above the cut line will remain in the sphincter seal to maintain the glove-box seal. The puck can and the lower plug half below the cut line is lowered into the bagless transfer enclosure. A floor-mounted robot in this enclosure will swipe the can exterior for contamination and place the can in a leak-detection chamber. If the can passes the swipe and leak-detection tests, the robot will place it on a transfer cart and send it to a nondestructive assay station. If the can fails either test, it will be sent back to the can-loading glove box and opened, and the pucks will be reloaded into another can. The PIP is in the conceptual design stage, and the facility will begin operation in 2007.

  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. 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…

  3. Flipping over: inversion characteristics of a buoyant cylindrical puck during oblique water impact

    NASA Astrophysics Data System (ADS)

    Smith, Zachary; Truscott, Tadd

    2014-11-01

    The Apollo Command Module had a tendency to flip over upon impact with the ocean surface after returning from space (9/19 times). In an effort to improve upon this idea for potential missions to Saturn's moon Titan, we present experimental results of a simplified buoyant cylindrical puck impacting the water surface. We examine the dependence of inversion upon vertical and horizontal velocity, center of gravity, and the pitch angle of the puck relative to the free surface. An analytical model is developed which characterizes inversion. High-speed images reveal that the puck does not completely submerge upon impact. Instead, the top of the puck remains above the water surface via a contact line attachment to the cavity. The asymmetric cavity then collapses, applying a moment, which can be sufficient to invert the puck after impact.

  4. 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)

  5. 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

  6. 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)

  7. The Puck Stops Here: Taking Organizational Accountability Seriously.

    PubMed

    Pinney, Stephen; Ho, Anita

    2016-01-01

    This commentary presents an ethical argument and practical suggestions for holding health administrators accountable for quality improvement efforts and results. Using hockey analogies and drawing on evidence from various studies and literature in organizational ethics, it argues that health leaders must promote system performance by ensuring that there is a well-organized delivery system around patients' episodes of care and that all personnel are performing at an acceptable level. Informed by system transformation and successes in the UK, this commentary proposes four strategies to hold leaders accountable: require leaders to be familiar with front-line operations, adopt a service-line approach, evaluate organizational performance by analyzing and publicizing outcome metrics and utilize outcome-based incentives. PMID:27009703

  8. 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

  9. 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

  10. Hockey: Special Olympics Sports Skills Instructional Program.

    ERIC Educational Resources Information Center

    Special Olympics, Inc., Washington, DC.

    Suggestions for coaching and teaching hockey skills to mentally retarded persons are presented in this guide, one of seven booklets on Special Olympics Sports Skills Instructional Programs. An introductory section presents an overview of the sport, information on the organization of the training session, and a list of goals, objectives, and…

  11. 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

  12. 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.

  13. 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.

  14. Seasonal Mood Disturbances in Collegiate Hockey Players

    PubMed Central

    Rosen, Lionel W.; Shafer, Christine L.; Smokler, Carol; Carrier, David; McKeag, Douglas B.

    1996-01-01

    Objective: The purpose of this paper is to: 1) describe the seasonal affective disorder syndrome using a case illustration, 2) provide a simple and reliable method for identifying seasonal affective disorder, and 3) provide data as to the prevalence of the syndrome in a subset of collegiate hockey players. Design and Setting: Collegiate hockey players were selected, because their practices begin in the fall and play is completed in the spring. The teams selected for participation were from the far Northwest and the upper Midwest regions. Subjects: Sixty-eight Division I hockey players volunteered for the study. The three teams from which the subjects were chosen were located above latitude 42°/45' north. Subjects were from the northern latitudes. Measurements: The Seasonal Pattern Assessment Questionnaire was used to screen for seasonality. A sample of the athletes was also examined using the Hamilton Rating Scale for Depression together with the Diagnostic and Statistical Manual of Mental Disorders (4th ed) criteria for Seasonal Pattern Specifier. Results: Thirty-three (51%) were asymptomatic, 7 (11%) met the criteria for seasonal affective disorder, and 25 (39%) hockey players scored in the range that could classify them as candidates for subsyndromal seasonal affective disorder. Conclusions: The prevalence of seasonal affective disorder among our sample approximated the national norm for the northern latitudes. However, the prevalence of subsyndromal seasonal affective disorder in our population was 25% compared to 13% reported nationally. Light therapy has been shown to reverse the effects of the disorders; however, further research needs to be conducted to determine its acceptance and effectiveness by the athletic population. PMID:16558403

  15. 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.

  16. 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…

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

    MedlinePlus

    ... director of the University of Pittsburgh Medical Center's Sports Medicine Concussion Program. According to the USA Hockey Coaching ... D., research director, University of Pittsburgh Medical Center, Sports Medicine Concussion Program; John Kuluz, M.D., director, traumatic ...

  18. 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...

  19. Re-examining the home disadvantage in professional ice hockey.

    PubMed

    Gayton, William F; Perry, Scott M; Loignon, Andrew C; Ricker, Angela

    2011-04-01

    Occurrence of the home disadvantage in professional ice hockey was examined by analyzing shootout data from 2005 through 2008. Results indicated that teams involved in shootouts playing at their home arenas did not lose significantly more games at home than on the road. Results did not support the hypotheses that emphasize the roles of physical contact and diffusion of responsibility in accounting for past failures to find the home disadvantage in professional ice hockey. PMID:21667767

  20. 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.

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

    NASA Astrophysics Data System (ADS)

    Szymelfenig, Maria; Kotwicki, Lech; Graca, Bożena

    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 Kuźnica Hollow).

  2. 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)

  3. 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,…

  4. 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

  5. Premières observations astrométriques au sol de Puck

    NASA Astrophysics Data System (ADS)

    Descamps, Pascal; Marchis, Franck; Berthier, Jérôme; Prangé, Renée; Fusco, Thierry; Le Guyader, Claude

    The ten small inner moons of Uranus, discovered in 1986, have so far only been studied from space (Voyager 2, HST). The orbital elements derived from the observations indicate very weakly eccentric orbits for all of them but one (Ophelia). We present here the first ground-based astrometric observations of Puck, performed using an Adaptive Optics system. The long observing sequences permitted by ground-based facilities at ESO-La Silla, Chile (64.S-0289) revealed an eccentricity 100 times larger than previously believed. Such a disagreement with the actual theory may arise from the reduction itself based on the bright moons of Uranus, considered until now as precise astrometric references. To cite this article: P. Descamps et al., C. R. Physique 3 (2002) 121-128

  6. Relationship of physical fitness test results and hockey playing potential in elite-level ice hockey players.

    PubMed

    Burr, Jaime F; Jamnik, Roni K; Baker, Joseph; Macpherson, Alison; Gledhill, Norman; McGuire, E J

    2008-09-01

    The primary purpose of this study was to determine the fitness variables with the highest capability for predicting hockey playing potential at the elite level as determined by entry draft selection order. We also examined the differences associated with the predictive abilities of the test components among playing positions. The secondary purpose of this study was to update the physiological profile of contemporary hockey players including positional differences. Fitness test results conducted by our laboratory at the National Hockey League Entry Draft combine were compared with draft selection order on a total of 853 players. Regression models revealed peak anaerobic power output to be important for higher draft round selection in all positions; however, the degree of importance of this measurement varied with playing position. The body index, which is a composite score of height, lean mass, and muscular development, was similarly important in all models, with differing influence by position. Removal of the goalies' data increased predictive capacity, suggesting that talent identification using physical fitness testing of this sort may be more appropriate for skating players. Standing long jump was identified as a significant predictor variable for forwards and defense and could be a useful surrogate for assessing overall hockey potential. Significant differences exist between the physiological profiles of current players based on playing position. There are also positional differences in the relative importance of anthropometric and fitness measures of off-ice hockey tests in relation to draft order. Physical fitness measures and anthropometric data are valuable in helping predict hockey playing potential. Emphasis on anthropometry should be used when comparing elite-level forwards, whereas peak anaerobic power and fatigue rate are more useful for differentiating between defense. PMID:18714234

  7. Parenting, achievement strategies and satisfaction in ice hockey.

    PubMed

    Juntumaa, Birgitta; Keskivaara, Pertti; Punamäki, Raija-Leena

    2005-10-01

    The aim of this study is to understand adolescent players' satisfaction as a function of parenting styles, players' achievement strategies, and their norm breaking behavior. Finnish 14- and 16-year-old ice-hockey players (n=1018) completed a questionnaire measuring their achievement strategies (SAQ; Nurmi, Salmela--Aro & Haavisto, 1995 b), as well as scales of norm breaking and satisfaction, prepared for the present study. The parents (n=979) filled in scales measuring their parenting styles (CRPR; Pulkkinen, 1996) and attitudes towards norm breaking. Results revealed that players from authoritative families who showed a high level of mastery-orientation expressed high satisfaction in playing ice hockey. Results also showed negative associations between authoritative parenting and both task irrelevant and norm breaking behavior. Parents with parental stress and those with authoritarian parenting styles showed positive attitudes to norm breaking behavior, and players from authoritarian and parental stress homes showed norm breaking behavior in ice hockey. There was no association between norm breaking behavior and player satisfaction. Our results contribute to the planning of a coaching system that serves more educational and developmental purposes, and that encourages the desire to play ice hockey as a hobby. PMID:16179023

  8. Occupational and recreational noise exposure from indoor arena hockey games.

    PubMed

    Cranston, Cory J; Brazile, William J; Sandfort, Delvin R; Gotshall, Robert W

    2013-01-01

    Occupational and recreational noise exposures were evaluated at two sporting arenas hosting collegiate hockey games (Venue 1) and semi-professional hockey (Venue 2). A total of 54 personal noise dosimetry samples were taken over the course of seven home hockey games: 15 workers and 9 fans at Venue 1, and 19 workers and 11 fans at Venue 2. None of the sampled workers were overexposed to noise based on Occupational Safety and Health Administration criteria. However, 40% and 57% of workers at Venue 1 and 33% and 91% of fans at Venue 2 were overexposed based on ACGIH noise exposure criteria. Noise exposures for fans were significantly different between venues, but worker noise exposures between venues were not significantly different. In addition, extensive area noise monitoring was conducted at each venue to further characterize the stadium noise on a location-by-location basis. Mean equivalent sound pressure levels ranged from 81 to 96 dBA at Venue 1 and from 85 to 97 dBA at Venue 2. Mean noise peak levels ranged from 105 to 124 dBA at Venue 1, and from 110 to 117 dBA at Venue 2. These data reflect the potential for overexposure at indoor hockey events and are useful in characterizing occupational noise exposure of indoor arena support staff and may also provide a foundation for future noise control research in indoor sports arenas. PMID:23145529

  9. Asymmetry in body composition in female hockey players.

    PubMed

    Krzykała, M; Leszczyński, P

    2015-08-01

    The aim of the study was to determine if a sport in which one side of the body is dominant, like field hockey, influences regional body composition and bone mineral density (BMD) distribution in particular body segments, and whether the sporting level is a determining factor. Dual energy X-ray absorptiometry (DXA) method (Lunar Prodigy Advance; General Electric, Madison, USA) with the whole body scan was used to measure bone mineral density, fat mass and lean mass in 31 female field hockey players divided according to their sporting level. The morphological asymmetry level was assessed between two body sides and body segments in athletes from the National Team (n=17) and from the Youth Team (n=14) separately and between groups. Bone mineral density in the lower extremity and of the trunk was significantly asymmetric in favor of the left side in the National Team. In the case of the Youth Team, only the trunk BMD indicated clear left-right difference with left side dominance. Both the lean mass and fat mass values were relatively higher on the left side of all body segments and it related to both analyzed groups of athletes. The present study shows that playing field hockey contributes to laterality in body composition and BMD and that the sporting level is a determining factor. In most cases the left side dominated. A greater asymmetry level was observed in more experienced female field hockey players. PMID:26077573

  10. 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…

  11. 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 160 ms before the shot was made or 60 ms 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

  12. Hypothenar hammer syndrome from ice hockey stick-handling.

    PubMed

    Zayed, Mohamed A; McDonald, Joey; Tittley, Jacques G

    2013-11-01

    Ulnar artery thrombosis and hypothenar hammer syndrome are rare vascular complications that could potentially occur with repeated blows or trauma to the hand. Although initially reported as an occupational hazard among laborers and craftsmen, it has been observed more recently among recreationalists and athletes. Until now, it has never been reported as a complication in ice hockey players. In this case report, a 26-year-old Canadian professional ice hockey player presented with acute dominant right hand paleness, coolness, and pain with hand use. The patient used a wooden hockey stick with a large knob of tape at the end of the handle, which he regularly gripped in the palm of his right hand to help with face-offs and general stick-handling. Sonographic evaluation demonstrated no arterial flow in the distal right ulnar artery distribution, and ulnar artery occlusion with no aneurysmal degeneration was confirmed by magnetic resonance angiogram. Intraarterial thrombolytic therapy was initiated, and subsequent serial angiograms demonstrated significant improvement in distal ulnar artery flow as well as recanalization of right hand deep palmar arch and digital arteries. The patient's symptoms resolved, and he was maintained on therapeutic anticoagulation for 3 months prior to returning to playing ice hockey professionally, but with a padded glove and no tape knob at the handle tip. This case highlights a unique presentation of hockey stick-handling causing ulnar artery thrombosis that was likely from repeated palmar hypothenar trauma. Appropriate diagnostic imaging, early intraarterial thrombolysis, and postoperative surveillance and follow-up were crucial for the successful outcome in this patient. PMID:23988538

  13. 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

  14. PUCK: An Automated Prompting System for Smart Environments: Towards achieving automated prompting; Challenges involved.

    PubMed

    Das, Barnan; Cook, Diane J; Schmitter-Edgecombe, Maureen; Seelye, Adriana M

    2012-10-01

    The growth in popularity of smart environments has been quite steep in the last decade and so has the demand for smart health assistance systems. A smart home-based prompting system can enhance these technologies to deliver in-home interventions to users for timely reminders or brief instructions describing the way a task should be done for successful completion. This technology is in high demand given the desire of people who have physical or cognitive limitations to live independently in their homes. In this paper, with the introduction of the "PUCK" prompting system, we take an approach to automate prompting-based interventions without any predefined rule sets or user feedback. Unlike other approaches, we use simple off-the-shelf sensors and learn the timing for prompts based on real data that is collected with volunteer participants in our smart home test bed. The data mining approaches taken to solve this problem come with the challenge of an imbalanced class distribution that occurs naturally in the data. We propose a variant of an existing sampling technique, SMOTE, to deal with the class imbalance problem. To validate the approach, a comparative analysis with Cost Sensitive Learning is performed. PMID:25364323

  15. Seagrass vegetation and meiofauna enhance the bacterial abundance in the Baltic Sea sediments (Puck Bay).

    PubMed

    Jankowska, Emilia; Jankowska, Katarzyna; Włodarska-Kowalczuk, Maria

    2015-09-01

    This study presents the first report on bacterial communities in the sediments of eelgrass (Zostera marina) meadows in the shallow southern Baltic Sea (Puck Bay). Total bacterial cell numbers (TBNs) and bacteria biomass (BBM) assessed with the use of epifluorescence microscope and Norland's formula were compared between bare and vegetated sediments at two localities and in two sampling summer months. Significantly higher TBNs and BBM (PERMANOVA tests, P < 0.05) were recorded at bottom covered by the seagrass meadows in both localities and in both sampling months. The relationships between bacteria characteristics and environmental factors (grain size, organic matter, photopigments in sediments), meiofauna and macrofauna densities, as well as macrophyte vegetation characteristics (shoot density, phytobenthos biomass) were tested using PERMANOVA distance-based linear model (DISTLM) procedures and showed that the main factors explaining bacteria characteristics are bottom type (vegetated vs. unvegetated) and meiofauna density. These two factors explained together 48.3% of variability in TBN and 40.5% in BBM, and their impacts did not overlap (as indicated by DISTLM sequential tests) demonstrating the different natures of these relationships. The effects of seagrass were most probably related to the increase of organic matter and providing habitat while higher numbers of meiofauna organisms may have stimulated the bacterial growth by increased grazing. PMID:26178839

  16. National survey of spinal injuries in hockey players.

    PubMed

    Tator, C H; Edmonds, V E

    1984-04-01

    There has been an alarming increase in the number of spinal injuries in hockey players. Between 1976 and 1983, 42 were reported to the Committee on Prevention of Spinal Injuries due to Hockey. The median age of the injured players was 17 years. Of the 42 players 28 had spinal cord injuries, and 17 of them had complete paralysis below the vertebral level of the injury. Strikes from behind and collisions with the boards were common mechanisms of injury. Many of the players had suffered a burst fracture of the cervical spine following a blow to the top of the helmet when the neck was slightly flexed. The committee studied a number of possible etiologic factors and made several recommendations regarding prevention. League officials, coaches, players and equipment manufacturers can all play a role in prevention. PMID:6704840

  17. 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

  18. [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

  19. The competitive demands of elite male field hockey.

    PubMed

    Boyle, P M; Mahoney, C A; Wallace, W F

    1994-09-01

    To establish the energy cost of competitive field hockey, nine international hockey players wore a modified Sport Tester PE3000 telemetric heart rate monitor during matchplay and also completed a laboratory based incremental treadmill test to establish maximal oxygen uptake (VO2max). The heart rate data from competition were compared with heart rate and oxygen uptake data measured in the laboratory. Individual regression equations were established from these data to estimate the energy penditure during competitive match-play. The mean heart rate during competition was 159 +/- 8 beats/min (mean +/- SD). The mean estimated oxygen uptake during competition was 48.2 +/- 5.2 ml/kg/min which is commensurate with 78% of the group's mean maximal oxygen uptake of 61.8 +/- 1.8 ml/kg/min. The mean estimated energy expenditure throughout an entire match was 5.19 MJ and rates of energy expenditure ranged from 83 kJ/min for the centre midfield position to 61.1 kJ/min for the left corner forward position. This study has shown the feasibility of heart rate monitoring as a means of estimating energy expenditure in elite hockey. Competitive matches place a heavy demand on the aerobic system and require players to expend energy at relatively high levels. PMID:7830386

  20. 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

  1. 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

  2. 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

  3. 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

  4. In situ calibration of the Gamma Reaction History instrument using reference samples ("pucks") for areal density measurements

    NASA Astrophysics Data System (ADS)

    Hoffman, N. M.; Herrmann, H. W.; Kim, Y. H.; Hsu, H. H.; Horsfield, C. J.; Rubery, M. S.; Wilson, D. C.; Stoeffl, W. W.; Young, C. S.; Mack, J. M.; Miller, E. K.; Grafil, E.; Evans, S. C.; Sedillo, T. J.; Glebov, V. Yu.; Duffy, T.

    2013-11-01

    The introduction of a sample of carbon, for example a disk or "puck", near an imploding DT-filled capsule creates a source of 12C gamma rays that can serve as a reference for calibrating the response of the Gamma Reaction History (GRH) detector [1]. Such calibration is important in the measurement of ablator areal density ⟨ρR⟩abl in plastic-ablator DT-filled capsules at OMEGA [2], by allowing ⟨ρR⟩abl to be inferred as a function of ratios of signals rather than from absolute measurements of signal magnitudes. Systematic uncertainties in signal measurements and detector responses therefore cancel, permitting more accurate measurements of ⟨ρR⟩abl.

  5. The effect of a complex training program on skating abilities in ice hockey players.

    PubMed

    Lee, Changyoung; Lee, Sookyung; Yoo, Jaehyun

    2014-04-01

    [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

  6. Sports chiropractic management at the World Ice Hockey Championships

    PubMed Central

    2010-01-01

    Background Ice hockey is an international sport. Injuries occur in a full body fashion, to a number of tissues, commonly through body contact. There is a lack of literature documenting the scope of sports chiropractic practice. Thus, it was the aim to document the type, scope and severity of conditions presenting to, and the treatment provided by, the New Zealand team chiropractor acting as a primary health provider for the duration of the 2007 World Ice Hockey Championships. Methods All conditions presenting were recorded. Diagnosis was recorded along with clinical parameters of injury: injury type, severity, mechanism and whether referral or advanced imaging was required. All treatment provided was continuously recorded, including information on the number of treatments required and the reason, duration, type and location of treatment. Results Players presented for diagnosis of injury 50 times. Muscle (34%), joint (24%) and tendon injuries (18%) were most common. Players presented with a new injury 76% of the time. Most injuries had been present for less than one week (84%), with 53% occurring through a contact mechanism. Injuries were common at training and match locations. Only two injuries required the player to stop playing or training, both of which were referred for advanced imaging. During the study, 134 treatment consultations were rendered to 45 player injuries. Eighty per-cent of injuries were managed with four or less treatments. Three quarters of treatment was provided at training locations with treatment duration predominantly being between 11-15 minutes (71%) and 16-20 minutes (27%). Most treatment delivered was passive in nature (71%) although combination active and passive care was provided (27%). Treatment typically involved joint (81%) and soft tissue based therapies (81%) and was delivered in a full body manner. Conclusions This study documented the injury profile of ice hockey at an international level of competition. It documented the conditions presenting to a chiropractor for diagnosis and the treatment provided. Treatment was consistent with that recommended for chiropractic management of athletic injuries. This documentation of sports chiropractic scope of practice fills a void in the literature and assists in determining a role for sports chiropractors as primary health providers or in multidisciplinary sports management teams. PMID:21129212

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

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

    PubMed

    Güllich, 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

  14. 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

  15. [Hematologic aspects of the national hockey team athletes].

    PubMed

    Faintuch, J J; Leite, J J; Munhoz, M A; Carazzato, J G

    1997-01-01

    Athletes tend to have lower hemoglobin (Hb) concentrations than sedentary counterparts. Sports anemia is used to describe both pseudodilutional anemia and the true anemia of athletes. Pseudodilutional anemia is a beneficial adaptation to endurance training; the two most common causes of true anemia are iron deficiency and intravascular hemolysis. We used questionnaires, physical examination and laboratory investigation to study 19 highly trained hockey athletes and laboratory investigation to study 32 outpatients without hematological diseases. One athlete had anemia (Hb 10.5 g/ dL; 5.44 million red cells/mL; serum iron-13 micrograms/dL; without parasites in the stools); the athletes had Hb = 14.88 +/- 1.33 g/dL and the outpatients had 15.24 +/- 0.74 g/dL; the maximal oxygen uptake of the athletes was 54.0 +/- 6.03 ml/kg/min (112.15 +/- 14.35% of the predicted values). The maximal oxygen uptake of the anemic athlete was 86% of the predicted value. The three athletes with the best maximal uptake had a mean Hb = 15.8 g/dL. In São Paulo-Brazil anemia is uncommon among males but elite athletes are in a borderline anemic state, that may impair the physical fitness. PMID:9334465

  16. Psychosocial Outcomes of Sport Concussions in Youth Hockey Players.

    PubMed

    Mrazik, Martin; Brooks, Brian L; Jubinville, Andrea; Meeuwisse, Willem H; Emery, Carolyn A

    2016-06-01

    The objective is to evaluate the psychological outcomes arising from sport concussions. Participants included AA and AAA level Bantam and Midget hockey players (n = 672) between 12 and 17 years of age (mean = 15.0 years; SD = 1.2) enrolled in a large cohort study. All participants completed baseline tests including the Behavior Assessment System for Children, 2nd Edition (BASC2) and a pre-season medical questionnaire (PSQ) completed by parents that included a retrospective report of prior concussions and injuries. Players were assigned to 4 groups: no injury (NONE), concussion (CO) and musculoskeletal (MSK) injuries or both (COMB). Participants in the CO and COMB groups demonstrated significantly higher rates of psychological difficulties compared with other groups [F(63, 1800) = 1.43, p = .016, partial η(2) = 0.05) and on select clinical scales measuring atypicality, locus of control, anxiety, depression, sense of inadequacy, somatization, and attention. In addition, results from the composite clinical scales reached statistical significance for internalizing problems and emotional symptom index. Effect sizes were minimal with the exception of comparisons between the NONE and COMB groups where effect sizes were medium to large. Proportions above clinical cut-off scores set by the BASC2 were higher for the COMB group compared with CO, MSK, or NONE groups. Results suggest smaller percentage of youth may be more prone to psychological sequelae following concussion. PMID:27084731

  17. 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

  18. Lesbian erotics at women's hockey: fans, flashing, and the Booby Orrs.

    PubMed

    Davidson, Judy

    2009-01-01

    This article analyzes a public breast flashing event that occurred during the women's ice hockey tournament at the OutGames/Western Cup Lesbigay athletic event in 2007. Employing a postfoundational perspective, I first contextualize the ice hockey subculture of the team called the Booby Orrs, outlining some of our history, norms, and context. I then tell the particular story that leads to our fans flashing their breasts as we finally scored some goals. I end with my analysis of this event: how a public nude display of sexualized women's breasts in a lesbian-coded public space prompted a resistant sporting moment, at least contingently. PMID:19598052

  19. 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.

  20. 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…

  1. 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…

  2. 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

  3. A test of motor skill-specific action embodiment in ice-hockey players.

    PubMed

    Ong, Nicole T; Lohse, Keith R; Chua, Romeo; Sinnett, Scott; Hodges, Nicola J

    2014-07-01

    To further our understanding of the role of the motor system in comprehending action-related sentences, we compared action experts (athletes) to visual experts (fans) and novices when responding with an action-specific effector (either hand or foot). These conditions allowed inferences about the degree and specificity of embodiment in language comprehension. Ice hockey players, fans and novices made speeded judgments regarding the congruence between an auditorily presented sentence and a subsequently presented picture. Picture stimuli consisted of either hockey or everyday items. Half of these pictures 'matched' the action implied in the preceding sentence. Further, the action in these images involved either primarily the hand or the foot. For everyday items, action-matched items were responded to faster than action-mismatched items. However, only the players and fans showed the action-match effect for hockey items. There were no consistent effector-stimuli compatibility effects, nor skill-based interactions with compatibility, suggesting that the action-match effect was not based on motor ability per se, but rather a construction of the action based on knowledge or visual experience with the hockey related sentences. PMID:24818535

  4. 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

  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. 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…

  8. 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

  9. 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

  10. 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…

  11. 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…

  12. 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…

  13. Hockey Concussion Education Project, Part 2. Microstructural white matter alterations in acutely concussed ice hockey players: a longitudinal free-water MRI study

    PubMed Central

    Pasternak, Ofer; Koerte, Inga K.; Bouix, Sylvain; Fredman, Eli; Sasaki, Takeshi; Mayinger, Michael; Helmer, Karl G.; Johnson, Andrew M.; Holmes, Jeffrey D.; Forwell, Lorie A.; Skopelja, Elaine N.; Shenton, Martha E.; Echlin, Paul S.

    2015-01-01

    Object Concussion is a common injury in ice hockey and a health problem for the general population. Traumatic axonal injury has been associated with concussions (also referred to as mild traumatic brain injuries), yet the pathological course that leads from injury to recovery or to long-term sequelae is still not known. This study investigated the longitudinal course of concussion by comparing diffusion MRI (dMRI) scans of the brains of ice hockey players before and after a concussion. Methods The 2011–2012 Hockey Concussion Education Project followed 45 university-level ice hockey players (both male and female) during a single Canadian Interuniversity Sports season. Of these, 38 players had usable dMRI scans obtained in the preseason. During the season, 11 players suffered a concussion, and 7 of these 11 players had usable dMRI scans that were taken within 72 hours of injury. To analyze the data, the authors performed free-water imaging, which reflects an increase in specificity over other dMRI analysis methods by identifying alterations that occur in the extracellular space compared with those that occur in proximity to cellular tissue in the white matter. They used an individualized approach to identify alterations that are spatially heterogeneous, as is expected in concussions. Results Paired comparison of the concussed players before and after injury revealed a statistically significant (p < 0.05) common pattern of reduced free-water volume and reduced axial and radial diffusivities following elimination of free-water. These free-water–corrected measures are less affected by partial volumes containing extracellular water and are therefore more specific to processes that occur within the brain tissue. Fractional anisotropy was significantly increased, but this change was no longer significant following the free-water elimination. Conclusions Concussion during ice hockey games results in microstructural alterations that are detectable using dMRI. The alterations that the authors found suggest decreased extracellular space and decreased diffusivities in white matter tissue. This finding might be explained by swelling and/or by increased cellularity of glia cells. Even though these findings in and of themselves cannot determine whether the observed microstructural alterations are related to long-term pathology or persistent symptoms, they are important nonetheless because they establish a clearer picture of how the brain responds to concussion. PMID:24490785

  14. 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 1.2–5.9 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

  15. The hockey-stick method to estimate evening dim light melatonin onset (DLMO) in humans.

    PubMed

    Danilenko, Konstantin V; Verevkin, Evgeniy G; Antyufeev, Viktor S; Wirz-Justice, Anna; Cajochen, Christian

    2014-04-01

    The onset of melatonin secretion in the evening is the most reliable and most widely used index of circadian timing in humans. Saliva (or plasma) is usually sampled every 0.5-1 hours under dim-light conditions in the evening 5-6 hours before usual bedtime to assess the dim-light melatonin onset (DLMO). For many years, attempts have been made to find a reliable objective determination of melatonin onset time either by fixed or dynamic threshold approaches. The here-developed hockey-stick algorithm, used as an interactive computer-based approach, fits the evening melatonin profile by a piecewise linear-parabolic function represented as a straight line switching to the branch of a parabola. The switch point is considered to reliably estimate melatonin rise time. We applied the hockey-stick method to 109 half-hourly melatonin profiles to assess the DLMOs and compared these estimates to visual ratings from three experts in the field. The DLMOs of 103 profiles were considered to be clearly quantifiable. The hockey-stick DLMO estimates were on average 4 minutes earlier than the experts' estimates, with a range of -27 to +13 minutes; in 47% of the cases the difference fell within ±5 minutes, in 98% within -20 to +13 minutes. The raters' and hockey-stick estimates showed poor accordance with DLMOs defined by threshold methods. Thus, the hockey-stick algorithm is a reliable objective method to estimate melatonin rise time, which does not depend on a threshold value and is free from errors arising from differences in subjective circadian phase estimates. The method is available as a computerized program that can be easily used in research settings and clinical practice either for salivary or plasma melatonin values. PMID:24224578

  16. Knee joint position sense of roller hockey players: a comparative study.

    PubMed

    Venâncio, João; Lopes, Diogo; Lourenço, Joaquim; Ribeiro, Fernando

    2016-06-01

    This study aimed to compare knee joint position sense of roller hockey players with an age-matched group of non-athletes. Forty-three male participants voluntarily participated in this cross-sectional study: 21 roller hockey players (mean age: 23.2 ± 4.2 years old, mean weight: 81.8 ± 9.8 kg, mean height: 180.5 ± 4.1 cm) and 22 age-matched non-athletes (mean age: 23.7 ± 3.9 years old, mean weight: 85.0 ± 6.2 kg, mean height: 181.5 ± 5.0 cm). Knee joint position sense of the dominant limb was evaluated using a technique of open-kinetic chain and active knee positioning. Joint position sense was reported using absolute, relative and variable angular errors. The main results indicated that the group of roller hockey players showed significantly lower absolute (2.4 ± 1.2º vs. 6.5 ± 3.2º, p ≤ 0.001) and relative (1.7 ± 2.1º vs. 5.8 ± 4.4º, p ≤ 0.001) angular errors in comparison with the non-athletes group. In conclusion, the results from this present study suggest that proprioceptive acuity, assessed by measuring joint position sense, is increased in roller hockey players. The enhanced proprioception of the roller hockey players could contribute to injury prevention and improved performance during sporting activities. PMID:27111126

  17. 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

  18. 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.

  19. 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.

  20. 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)

  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. [Test for the determination of endurance fitness and training style in young ice hockey players].

    PubMed

    Mona, D; Segantini, P; Comminot, C; Probst, H P; Furrer, D

    1989-10-01

    A test similar to the Conconi test was developed by the authors, to be used specifically with ice hockey players. The aim was to measure the aerobic performance capacity of these athletes. The results give us on one hand informations on the actual performance potential of these sportsmen. On the other hand, they enable us to design an optimal training schedule. With such data in hand, it becomes possible to determine which intensity of endurance training is optimally adapted to an individual's progress of performance. It is thus easier to develop the sought after basic fitness in youth players. 120 ice hockey players of several leagues had to go through either a Conconi test, or our modified, more sports specific Probst test. 54 of these were junior players (age 15-16). Our purpose in this paper is to discuss the aim of such endurance tests for youth players. PMID:2814429

  3. 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 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

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

    PubMed Central

    Gómez, M.; Martín-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

  5. Examination of birthplace and birthdate in World Junior ice hockey players.

    PubMed

    Bruner, Mark W; Macdonald, Dany J; Pickett, William; Côté, Jean

    2011-09-01

    The present study investigated birthdate (known as the Relative Age Effect; RAE) and birthplace as determinants of expertise in an international sample of elite ice hockey players. The sample included 566 World Junior (WJR) ice hockey players from four countries (Canada, n = 153; USA, n = 136; Sweden, n = 140; Finland, n = 137). Participants competed in the International Ice Hockey Federation World U20 Championship between 2001 and 2009. A series of Poisson regression models were conducted to examine the consistency of direct then interactive relationships between both birthdate and birthplace and WJR membership across the four countries (Canada, USA, Sweden, and Finland). Findings revealed a consistent RAE across the four countries for World Junior participation from 2000 to 2009. WJR players from the four countries were also less likely to be from major cities. In addition, there was no evidence in any of the four countries of an interaction between RAE and birthplace. Future research should explore the contextual and cultural factors that influence elite athlete development in smaller towns, cities and communities. PMID:21800970

  6. 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

  7. 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

  8. The Hockey Stick and the Climate Wars: Dispatches From The Front Lines

    NASA Astrophysics Data System (ADS)

    Mann, M. E.

    2011-12-01

    A central figure in the controversy over human-caused climate change has been The Hockey Stick, a simple, easy-to-understand graph my colleagues and I constructed to depict changes in Earth's temperature back to 1000 AD. The graph was featured in the high-profile Summary for Policy Makers of the 2001 report of the Intergovernmental Panel on Climate Change (IPCC), and it quickly became an icon in the debate over human-caused (anthropogenic) climate change. I will tell the story behind the Hockey Stick, using it as a vehicle for exploring broader issues regarding the role of skepticism in science, the uneasy relationship between science and politics, and the dangers that arise when special economic interests and those who do their bidding attempt to skew the discourse over policy-relevant areas of science. In short, I attempt to use the Hockey Stick to cut through the fog of disinformation that has been generated by the campaign to deny the reality of climate change. It is my intent, in so doing, to reveal the very real threat to our future that lies behind it.

  9. Trends in reporting of mechanisms and incidence of hip injuries in males playing minor ice hockey in Canada: a cross-sectional study

    PubMed Central

    Ayeni, Olufemi R; Kowalczuk, Marcin; Farag, Jordan; Farrokhyar, Forough; Chu, Raymond; Bedi, Asheesh; Willits, Kevin; Bhandari, Mohit

    2014-01-01

    Background There has been a noted increase in the diagnosis and reporting of sporting hip injuries and conditions in the medical literature but reporting at the minor hockey level is unknown. The purpose of this study is to investigate the trend of reporting hip injuries in amateur ice hockey players in Canada with a focus on injury type and mechanism. Methods A retrospective review of the Hockey Canada insurance database was performed and data on ice hockey hip injuries reported between January 2005 and June 2011 were collected. The study population included all male hockey players from Peewee (aged 11–12 years) to Senior (aged 20+ years) participating in amateur level competition sanctioned by Hockey Canada. Reported cases of ice hockey hip injuries were analyzed according to age, mechanism of injury, and injury subtype. Annual injury reporting rates were determined and using a linear regression analysis trended to determine the change in ice hockey hip injury reporting rate over time. Results One hundred and six cases of ice hockey-related hip injuries were reported in total. The majority of injuries (75.5%) occurred in players aged 15–20 years playing at the Junior level. Most injuries were caused by a noncontact mechanism (40.6%) and strains were the most common subtype (50.0%). From 2005 to 2010, the number of reported hip injuries increased by 5.31 cases per year and the rate of reported hip injury per 1,000 registered players increased by 0.02 cases annually. Conclusion Reporting of hip injuries in amateur ice hockey players is increasing. A more accurate injury reporting system is critical for future epidemiologic studies to accurately document the rate and mechanism of hip injury in amateur ice hockey players. PMID:24966705

  10. 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

  11. Posterior approach for arthroscopic treatment of posterolateral impingement syndrome of the ankle in a top-level field hockey player.

    PubMed

    Lohrer, Heinz; Arentz, Sabine

    2004-04-01

    A case history of a 25-year-old field hockey player, a member of the German National Field Hockey Team, is presented. The patient could not remember any specific ankle injury, but since the World Indoor Championship in February 2003, he experienced significant but diffuse pain around the posterior ankle, especially while loading the forefoot in hockey training and competition. For 2 months, the patient was unable to run. Conservative treatment failed, and surgery was performed. Posterior ankle arthroscopy revealed a frayed posterior intermalleolar ligament and meniscoid-like scar tissue at the posterolateral ankle, indicating a posterolateral soft tissue ankle impingement syndrome. A concomitant inflammation of the posterolateral ankle and subtalar synovium was present. After arthroscopic resection and early functional aftertreatment, the patient returned to full high-level sports ability within 2 months. PMID:15067292

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

    PubMed Central

    Roczniok, R.; Maszczyk, A.; Pietraszewski, P.; Zając, 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 (3.10±1.16%). The total FI was 13.77±1.74%. 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

  13. 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

  14. 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

  15. Effect of Increasing Maximal Aerobic Exercise on Serum Muscles Enzymes in Professional Field Hockey Players

    PubMed Central

    Hazar, Muhsin; Otağ, Aynur; Otağ, İlhan; Sezen, Mehmet; Sever, Ozan

    2015-01-01

    Background and Objectives: Exercise results in oxidative enzyme increase and micro-injuries in skeletal muscles. The aim of this study was to investigate the effect of maximal aerobic exercise on serum muscle enzymes in professional field hockey players. This study aims to determine the effect of increasing maximal aerobic exercise on creatine kinase (CK), creatine kinase-MB (CK-MB), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) serum levels. Material and Methods: 31 young professional field hockey players (13 female and 18 male players) volunteered for this study. All participants underwent the shuttle run test. Blood samples were taken from each participant before the shuttle run test. Post test blood samples were taken immediately after exercise and one hour after respectively. Pre and post test CK, CK-MB, AST and ALT values were measured by means of auto analyzer using original kits. Results: The acute post test measure of the CK level increased in male (p=0.002) and female (p=0.00) sportsmen. CK-MB values obtained one hour after the exercise was lower than those before the exercise in males (p=0.02). In females (p=0.017) and males (p=0.05) AST activity significantly increased immediately after exercise and decreased to resting activity 1 h recovery. ALT significantly increased immediately after exercise in female (p=0.03) and male (p=0.00) athletes and after 1 h recovery ALT activities decreased below resting values. Conclusion: The timing and severity of exercise used in our study increased CK values, decreased CK-MB values and AST, ALT values increased in female and male field hockey players. PMID:25948428

  16. 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

  17. Carbon monoxide in indoor ice skating rinks: evaluation of absorption by adult hockey players.

    PubMed Central

    Lévesque, B; Dewailly, E; Lavoie, R; Prud'Homme, D; Allaire, S

    1990-01-01

    We evaluated alveolar carbon monoxide (CO) levels of 122 male, adult hockey players active in recreational leagues of the Quebec City region (Canada), before and after 10 weekly 90-minute games in 10 different rinks. We also determined exposure by quantifying the average CO level in the rink during the games. Other variables documented included age, pulmonary function, aerobic capacity, and smoking status. Environmental concentrations varied from 1.6 to 131.5 parts per million (ppm). We examined the absorption/exposure relationship using a simple linear regression model. In low CO exposure levels, physical exercise lowered the alveolar CO concentration. However, we noted that for each 10 ppm of CO in the ambient air, the players had adsorbed enough CO to raise their carboxyhemoglobin (COHb) levels by 1 percent. This relationship was true both for smokers and non-smokers. We suggest that an average environmental concentration of 20 ppm of CO for the duration of a hockey game (90 minutes) should be reference limit not to be exceeded in indoor skating rinks. PMID:2327538

  18. 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

  19. Carbon monoxide in indoor ice skating rinks: Evaluation of absorption by adult hockey players

    SciTech Connect

    Levesque, B.; Dewailly, E.; Lavoie, R.; Prud'Homme, D.; Allaire, S. )

    1990-05-01

    We evaluated alveolar carbon monoxide (CO) levels of 122 male, adult hockey players active in recreational leagues of the Quebec City region (Canada), before and after 10 weekly 90-minute games in 10 different rinks. We also determined exposure by quantifying the average CO level in the rink during the games. Other variables documented included age, pulmonary function, aerobic capacity, and smoking status. Environmental concentrations varied from 1.6 to 131.5 parts per million (ppm). We examined the absorption/exposure relationship using a simple linear regression model. In low CO exposure levels, physical exercise lowered the alveolar CO concentration. However, we noted that for each 10 ppm of CO in the ambient air, the players had adsorbed enough CO to raise their carboxyhemoglobin (COHb) levels by 1 percent. This relationship was true both for smokers and non-smokers. We suggest that an average environmental concentration of 20 ppm of CO for the duration of a hockey game (90 minutes) should be reference limit not to be exceeded in indoor skating rinks.

  20. 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

  1. “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

  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. 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

  4. 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)

  5. Development and Validation of a Method for Determining Tridimensional Angular Displacements with Special Applications to Ice Hockey Motions.

    ERIC Educational Resources Information Center

    Gagnon, Micheline; And Others

    1983-01-01

    A method for determining the tridimensional angular displacement of skates during the two-legged stop in ice hockey was developed and validated. The angles were measured by geometry, using a cinecamera and specially equipped skates. The method provides a new tool for kinetic analyses of skating movements. (Authors/PP)

  6. Enforcement of Mouthguard Use and Athlete Compliance in National Collegiate Athletic Association Men's Collegiate Ice Hockey Competition.

    ERIC Educational Resources Information Center

    Hawn, Kristen L.; Visser, Mary Frances; Sexton, Patrick J.

    2002-01-01

    Investigated enforcement patterns and athlete compliance with the National Collegiate Athletic Association rule requiring the wearing of mouthguards in men's collegiate ice hockey games during one season. Surveys of athletic trainers indicated that the use of mouthguards in competition was not consistently enforced by athletic trainers, coaches,…

  7. 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

  8. 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

  9. Hockey Concussion Education Project, Part 1: Susceptibility-weighted imaging study in male and female ice hockey players over a single season

    PubMed Central

    Helmer, Karl G.; Pasternak, Ofer; Fredman, Eli; Preciado, Ronny I.; Koerte, Inga K.; Sasaki, Takeshi; Mayinger, Michael; Johnson, Andrew M.; Holmes, Jeffrey D.; Forwell, Lorie; Skopelja, Elaine N.; Shenton, Martha E.; Echlin, Paul S.

    2015-01-01

    Object Concussion, or mild traumatic brain injury (mTBI), is a commonly occurring sports-related injury, especially in contact sports such as hockey. Cerebral microbleeds (CMBs), which are small, hypointense lesions on T2*-weighted images, can result from TBI. The authors use susceptibility-weighted imaging (SWI) to automatically detect small hypointensities that may be subtle signs of chronic and acute damage due to both subconcussive and concussive injury. The goal was to investigate how the burden of these hypointensities change over time, over a playing season, and postconcussion, compared with subjects who did not suffer a medically observed and diagnosed concussion. Methods Images were obtained in 45 university-level adult male and female ice hockey players before and after a single Canadian Interuniversity Sports season. In addition, 11 subjects (5 men and 6 women) underwent imaging at 72 hours, 2 weeks, and 2 months after concussion. To identify subtle changes in brain tissue and potential CMBs, nonvessel clusters of hypointensities on SWI were automatically identified and a hypointensity burden index was calculated for all subjects at the beginning of the season (BOS) and the end of the season (EOS), in addition to postconcussion time points (where applicable). Results A statistically significant increase in the hypointensity burden, relative to the BOS, was observed for male subjects at the 2-week postconcussion time point. A smaller, nonsignificant rise in the burden for all female subjects was also observed within the same time period. The difference in hypointensity burden was also statistically significant for men with concussions between the 2-week time point and the BOS. There were no significant changes in burden for nonconcussed subjects of either sex between the BOS and EOS time points. However, there was a statistically significant difference in the burden between male and female subjects in the nonconcussed group at both the BOS and EOS time points, with males having a higher burden. Conclusions This method extends the utility of SWI from the enhancement and detection of larger (> 5 mm) CMBs that are often observed in more severe TBI, to concussion in which visual detection of injury is difficult. The hypointensity burden metric proposed here shows statistically significant changes over time in the male subjects. A smaller, nonsignificant increase in the burden metric was observed in the female subjects. PMID:24490839

  10. Ice hockey lung – a case of mass nitrogen dioxide poisoning in the Czech Republic

    PubMed Central

    Brat, Kristian; Merta, Zdenek; Plutinsky, Marek; Skrickova, Jana; Ing, Miroslav Stanek

    2013-01-01

    Nitrogen dioxide (NO2) is a toxic gas, a product of combustion in malfunctioning ice-resurfacing machines. NO2 poisoning is rare but potentially lethal. The authors report a case of mass NO2 poisoning involving 15 amateur ice hockey players in the Czech Republic. All players were treated in the Department of Respiratory Diseases at Brno University Hospital in November 2010 – three as inpatients because they developed pneumonitis. All patients were followed-up until November 2011. Complete recovery in all but one patient was achieved by December 2010. None of the 15 patients developed asthma-like disease or chronic cough. Corticosteroids appeared to be useful in treatment. Electric-powered ice-resurfacing machines are preferable in indoor ice skating arenas. PMID:24032121

  11. Cardiovascular Prevention in a High Risk Sport, Ice Hockey: Applications in Wider Sports Physical Therapy Practice

    PubMed Central

    2006-01-01

    Although acute myocardial infarction and sudden cardiac death are relatively rare occurrences in athletics, cardiovascular accidents do occur. This manuscript presents information on the cardiovascular risks in athletics. In addition, information is provided on screening for cardiovascular risk – including history taking, chart review, physical examination – and the appropriate guidelines on the treatment of athletes found to be at risk. For the purpose of this article, the sport of ice hockey is used to illustrate the subject matter and highlight the behaviors in sport that carry cardiovascular risk. Physical therapists have ethical and legal responsibility to undertake the necessary screening procedures to recognize and respond to any signs of cardiovascular risk in their clients. PMID:21522221

  12. 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

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

    PubMed

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

    2016-01-01

    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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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…

  20. Pulmonary function decay in women ice hockey players: is there a relationship to ice rink air quality?

    PubMed

    Rundell, Kenneth W

    2004-03-01

    Fossil-fueled ice rink resurfacing machines emit high levels of ultrafine and fine particulate matter (PM(1)) and may be related to asthmalike symptoms in skaters. We examined PM(1) exposure and airway status in elite women ice hockey players over 4 training years. Lung function, asthma symptoms, and rink PM(1) were evaluated. Pre- and postexercise spirometry was performed on 14 female hockey players and 9 female control nordic skiers 4 times over 4 yr. Baseline lung functions were normalized to height cubed (Ht(3)) and recalculated to subject mean height (1.69 m) to evaluate change. Venue CO, NO(2), and PM(1) were measured. Training history for hockey players included 2 yr in a low-[PM(1)] rink, followed by transition to high-[PM(1)] fossil fuel machine resurfaced rinks; [PM(1)] for control ski venue was low. [CO] and [NO(2)] were acceptable at all venues. Controls showed no baseline function change over 4 yr. For hockey players, 1997 lung function values at the low-[PM(1)] venue were significantly higher than 2001 high-[PM(1)] venue values (p <.05); decay per year between 1997 and 2001 was greater for FEF(25-75) (251 +/- 185, 83 +/- 40, 109 +/- 58, 109 +/- 187 ml yr(-1), mean +/- SD for FEF(25-75), FVC, FEV1, PEF, respectively; p <.05). No relationships between baseline lung functions and airway hyperresponsiveness or symptoms were identified. Five of 9 controls had symptoms, and 10 of 14 subjects had symptoms. This preliminary study suggests [PM(1)] is related to airway function decay in ice rink athletes. PMID:15204772

  1. 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 Fisher’s 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

  2. Test-Retest Reliability of Computerized Neurocognitive Testing in Youth Ice Hockey Players.

    PubMed

    Womble, Melissa N; Reynolds, Erin; Schatz, Philip; Shah, Kishan M; Kontos, Anthony P

    2016-06-01

    Computerized neurocognitive tests are frequently used to assess pediatric sport-related concussions; however, only 1 study has focused on the test-retest reliability of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) in high school athletes and age influences have largely been ignored. Therefore, the purpose was to investigate the test-retest reliability of ImPACT and underlying age influences in a pediatric population. Two hundred (169 men and 31 women) youth ice hockey players completed ImPACT before/after a 6-month season. Reliability was assessed using Pearson correlation coefficients, intraclass correlation coefficients (ICCs), and regression-based methods (RBz). ICCs for the sample ranged from .48 to .75 (single)/.65 to .86 (average). In general, the older athletes (15-18: Single/Average ICCs = .35-.75/.52-.86) demonstrated greater reliability across composites than the younger athletes (11-14: Single/Average ICCs = .54-.63/.70-.77). Although there was variation in athletes' performance across two test administrations, RBz revealed that only a small percentage of athletes performed beyond 80%, 90%, and 95% confidence intervals. Statistical metrics demonstrated reliability coefficients for ImPACT composites in a pediatric sample similar to previous studies, and also revealed important age-related influences. PMID:27084734

  3. Perceived tiredness and heart rate variability in relation to overload during a field hockey World Cup.

    PubMed

    Parrado, Eva; Cervantes, Julio; Pintanel, Monica; Rodas, Gil; Capdevila, Lluís

    2010-06-01

    The aim of the study was to examine the utility of perceived tiredness to predict cardiac autonomic response to overload among field hockey players during the 2006 World Cup. The French Society for Sports Medicine (SFMS) questionnaire was administered at the start of the Cup to evaluate perception of tiredness. Autonomic function was assessed nine days later at the semifinal match by time and frequency domain analysis of heart rate variability. An anxiety questionnaire was administered so that the effect of precompetitive anxiety on heart rate variability could be controlled. Results showed a negative correlation between perceived tiredness scores and time domain indexes, and a positive correlation of perceived tiredness scores and the high frequency component ratio (LF/HF ratio) of heart rate variability. Anxiety did not influence the precompetitive cardiac response despite somatic anxiety's correlation with sympathetic response (LF/HF ratio) and tiredness scores. Perceived tiredness predicted the autonomic cardiac response to competitive overload. Thus, the perceived tiredness assessment would be a good early marker of fatigue and overload states during competition. PMID:20681325

  4. 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 12.9 kg, 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

  5. Changes in white matter microstructure in ice hockey players with a history of concussion: a diffusion tensor imaging study

    PubMed Central

    Sasaki, Takeshi; Pasternak, Ofer; Mayinger, Michael; Muehlmann, Marc; Savadjiev, Peter; Bouix, Sylvain; Kubicki, Marek; Fredman, Eli; Dahlben, Brian; Helmer, Karl; Johnson, Andrew M.; Holmes, Jeff D.; Forwell, Lori A.; Skopelja, Elaine; Shenton, Martha E.; Echlin, Paul; Koerte, Inga K.

    2016-01-01

    Object The aim of this study was to examine the brain’s white matter microstructure using magnetic resonance diffusion tensor imaging (DTI) in ice hockey players with a history of clinically symptomatic concussion compared to those players without a history of concussion. Methods Sixteen players with a history of concussion (Concussed Group; mean age: 21.7 ± 1.5 years; 6 female) and eighteen players without a history of concussion (Non-Concussed Group; mean age: 21.3 ± 1.8 years, 10 female) underwent 3T DTI at the end of the Canadian Interuniversity Sports ice hockey season 2011–2012. Tract-based spatial statistics (TBSS) was used to test for group differences in fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and trace. Cognitive evaluation was performed using the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) and the Sport Concussion Assessment Tool-2 (SCAT2). Results TBSS revealed a significant increase in FA and AD, and a significant decrease in RD and trace in several brain regions in the Concussed group, compared with the Non-concussed group (p < 0.05). The regions with increased FA and decreased RD and trace included the right posterior limb of the internal capsule, the right corona radiata, and the right temporal lobe. Increased AD was observed in a small area in the left corona radiata. DTI measures neither correlated with the ImPACT nor SCAT2. Conclusion The results of the current study indicate that a history of concussion may result in alterations of the brain’s white matter microstructure in ice hockey players. Increased FA based on decreased RD may reflect neuroinflammatory or neuroplastic processes of the brain responding to brain trauma. Future studies are needed that include a longitudinal analysis of the brain’s structure and function following a concussion in order to elucidate further the complex time course of DTI changes and their clinical meaning. PMID:24471841

  6. 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

  7. 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 player’s 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 player’s 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

  8. Predictors of repeated-sprint ability in elite female hockey players.

    PubMed

    Bishop, D; Lawrence, S; Spencer, M

    2003-06-01

    The ability to maintain maximal power over a series of sprints may depend, in part, on the resynthesis of PCr and the buffering of hydrogen ions (H+). As a result, repeated-sprint ability may be related to VO2peak and changes in plasma pH. Fourteen elite female field-hockey players (Mean +/- SD body mass: 61.1 +/- 5.9 kg and VO2pea: 55.7 +/- 3.2 mL x kg(-1) x min(-1)) participated in this investigation. Tests consisted of a repeated-sprint ability test (5 x 6-s all-out sprints every 30 s) and a VO2peak test. Capillary and venous blood was sampled before and after the 5 x 6-s cycle test for the determination of lactate concentration and pH. There were no significant correlations between VO2peak (mL x kg(-1) x min(-1)) and total work (J.kg(-1); r = 0.35), or power decrement (r = 0.30) during the repeated-sprint ability test. There was, however, a significant correlation between power decrement and change in plasma [H+] (r = 0.66; P < 0.05). The results of this study show that in a homogenous group of elite, team-sport athletes, VO2peak (mL x kg(-1) x min(-1)) is not a strong predictor of repeated-sprint ability. However, in this group, there is a significant correlation between change in plasma [H+] and repeated-sprint ability. PMID:12945626

  9. Muscle oxygen changes following Sprint Interval Cycling training in elite field hockey players.

    PubMed

    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 ± 0.14 m.s(-1)) but not the CON group (pre = 5.37 ± 0.27 to 5.39 ± 0.30 m.s(-1)) significant changes were seen in the 30-15 IFT 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 ± 26.48 μM.cm); and ΔHbO2+ MbO2 (-74.29 ± 13.82 to -109.36 ± 22.61 μM.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

  10. 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

  11. 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

  12. The influence of social variables and moral disengagement on prosocial and antisocial behaviours in field hockey and netball.

    PubMed

    Boardley, Ian D; Kavussanu, Maria

    2009-06-01

    In this study, we examined: (a) the effects of perceived motivational climate and coaching character-building competency on prosocial and antisocial behaviours towards team-mates and opponents in field hockey and netball; (b) whether the effects of perceived character-building competency on sport behaviours are mediated by moral disengagement; and (c) whether these relationships are invariant across sport. Field hockey (n = 200) and netball (n = 179) players completed questionnaires assessing the aforementioned variables. Structural equation modelling indicated that mastery climate had positive effects on prosocial and negative effects on antisocial behaviour towards team-mates, while performance climate had a positive effect on antisocial behaviour towards team-mates. Perceived character-building competency had a positive effect on prosocial behaviour towards opponents and negative effects on the two antisocial behaviours; all of these effects were mediated by moral disengagement. No effect was found for prosocial behaviour towards team-mates. The model was largely invariant across sport. The findings aid our understanding of social influences on prosocial and antisocial behaviours in sport. PMID:19449250

  13. 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,…

  14. 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,

  15. 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

  16. 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

  17. The influence of gender-related beliefs and conceptions of ability on women learning the hockey wrist shot.

    PubMed

    Belcher, Don; Lee, Amelia M; Solmon, Melinda A; Harrison, Louis

    2003-06-01

    The purpose of this study was to determine the influence of beliefs about gender appropriateness and conceptions of ability on perceived and actual competene and patterns of behavior during practice of the hockey wrist shot. Sixty-eight undergraduate women formed four treatment conditions based on their beliefs about gender appropriateness and conceptions of ability. Four teachers taught across the treatment conditions for a total of 16 learning groups. Data were collected through a three-part questionnaire and from audio-video taping of the entire episode to ascertain the paticipants' competency beliefs, effort, and performance. Gender appropriateness impacted the participants' perceptions of competence and actual performance in the study, while beliefs about conceptions of ability did not produce a significant difference. This study reaffirms that educators must work diligently to combat the stereotypical beliefs many hold with respect to the gender appropriateness of physical activities. PMID:12848231

  18. Association Between Vitamin D Status and Maximal-Intensity Exercise Performance in Junior and Collegiate Hockey Players.

    PubMed

    Fitzgerald, John S; Peterson, Ben J; Warpeha, Joseph M; Johnson, Sam C; Ingraham, Stacy J

    2015-09-01

    Recent evidence suggests that athletes are at risk for poor vitamin D status. This study used a cross-sectional design to investigate the strength of association between 25-hydroxyvitamin D (25(OH)D) concentration and measures of maximal-intensity exercise performance in competitive hockey players. Fifty-three collegiate and junior male ice hockey players training near Minneapolis, MN (44.9° N latitude) participated in the study during the off-season (May 16-June 28). Circulating 25(OH)D concentration, grip strength, vertical jump performance, and power production during the Wingate Anaerobic Test (WAnT) were evaluated. Despite no athletes with 25(OH)D concentration indicative of deficiency (<20 ng·mL), positive bivariate correlations were detected between vitamin D status, relative grip strength (p = 0.024), and peak power during the WAnT (p = 0.035). Only for relative grip strength (p = 0.043), did 25(OH)D concentration predict performance after adjusting for level of play, fat-free mass, fat mass, and self-reported total physical activity in sequential linear regression. Vitamin D status was positively associated with starting gradient (p = 0.020) during the squat jump, with higher concentrations associated with increased rate of force development in the initial portion of the jump. Interventional trials should investigate the impact of vitamin D supplementation on maximal-intensity exercise performance outcomes and rate of force development in large samples of vitamin D-deficient athletes while controlling for training exposure. Our data indicate that if vitamin D status is causally related to maximal-intensity exercise performance in athletes, the effect size is likely small. PMID:26313575

  19. Chronic cough and dyspnea in ice hockey players after an acute exposure to combustion products of a faulty ice resurfacer.

    PubMed

    Kahan, Erika S; Martin, Ubaldo J; Spungen, Steve; Ciccolella, David; Criner, Gerard J

    2007-01-01

    The aim of this study was to characterize pulmonary function and radiologic testing in ice hockey players after exposure to combustion products of a faulty ice resurfacer. Our patients were 16 previously healthy hockey players who developed chronic cough and dyspnea after exposure. Symptom questionnaires, pulmonary function tests (PFTs), bronchoprovocation testing, cardiopulmonary exercise testing, high-resolution computed tomography (CT) imaging, and impulse oscillometry (IOS) were all used. A normal group was used for PFTs and IOS controls. Patients had onset of cough within 72 h of exposure. Ninety-two percent complained of dyspnea, 75% chest pain, and 33% hemoptysis. Eight percent were initially hospitalized for their symptoms. Eighty-five percent were treated with systemic steroids and 39% with inhaled bronchodilators. Six months postexposure, 54% complained of cough and 46% complained of dyspnea on exertion. All patients had normal PFTs; 8.3% had a significant bronchodilator response. All had normal exercise tests (mean VO2max = 90 +/- 3% predicted) and chest CTs. With IOS, 80% had a significant bronchodilator response (decreased resistance > 12% and SD score > 1; mean change = 21.1 +/- 9.9%, mean SD score = 3.1 +/- 2.5). No correlation existed between changes in resistance or reactance and spirometric values. Patient symptoms correlated significantly with bronchodilator response on IOS resistance (R=0.61, p=0.03). More than 50% of patients exposed to the combustion products of a faulty ice resurfacer remained symptomatic six months after exposure. Despite persistence of symptoms, conventional pulmonary function tests and radiologic evaluation did not reveal airway abnormalities. IOS showed evidence of increased airway resistance and small-airway disease, which correlated with patient symptoms. PMID:17294334

  20. 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

  1. 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

  2. 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

  3. 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

  4. Descriptive Epidemiology of Collegiate Women's Field Hockey Injuries: National Collegiate Athletic Association Injury Surveillance System, 1988–1989 Through 2002–2003

    PubMed Central

    Dick, Randall; Hootman, Jennifer M; Agel, Julie; Vela, Luzita; Marshall, Stephen W; Messina, Renee

    2007-01-01

    Objective: To review 15 years of National Collegiate Athletic Association (NCAA) injury surveillance data for women's field hockey and identify potential areas for injury prevention initiatives. Background: Field hockey is one of the most popular sports worldwide and is growing in participation in the United States, particularly among women. From 1988–1989 to 2002–2003, participation in NCAA women's field hockey increased 12%, with the largest growth among Division III programs. In 2002– 2003, 253 colleges offered women's field hockey and 5385 women participated. Main Results: Game injury rates showed a significant average annual 2.5% decline over 15 years, most likely fueled by drops in ankle ligament sprain, knee internal derangement, and finger fracture injuries. Despite this, ankle ligament sprains were common (13.7% of game and 15.0% of practice injuries) and a frequent cause of severe injuries (resulting in 10+ days of time-loss activity). Concussion and head laceration injuries increased over this same time, and the risk of sustaining a concussion in a game was 6 times higher than the risk of sustaining one during practice. Overall, injury rates were twice as high in games as in practices (7.87 versus 3.70 injuries per 1000 athlete-exposures, rate ratio = 2.1, 95% confidence interval = 2.0, 2.3). Most head/neck/face (71%) and hand/finger/thumb (68%) injuries occurred when the player was near the goal or within the 25-yd line and were caused by contact with the stick or ball (greater than 77% for both body sites); for 34% of head/neck/ face injuries, a penalty was called on the play. Recommendations: Equipment (requiring helmets and padded gloves) and rule changes (to decrease field congestion near the goal) as well as evidence-based injury prevention interventions (eg, prophylactic ankle taping/bracing, neuromuscular balance exercise programs) may be viable prevention initiatives for reducing injury rates in women's collegiate field hockey players. PMID:17710169

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

    PubMed

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

    2016-01-01

    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. Sixteen ice-hockey players, members of the Polish national team junior (U20), performed an incremental test to assess their maximal oxygen uptake (VO2max) 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 b · min(-1) (HRmax, 75.2-79.5%), 152-176 b · min(-1) (HRmax, 80.0-92.4%), 177-190 b · min(-1) (HRmax, 92.9-100.0%); defensemen, 127-139 b · min(-1) (HRmax, 69.4-75.8%), 140-163 b · min(-1) (HRmax, 76.4-89.0%), 164-184 b · min(-1) (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

  6. 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

  7. 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.

  8. A simple video-based timing system for on-ice team testing in ice hockey: a technical report.

    PubMed

    Larson, David P; Noonan, Benjamin C

    2014-09-01

    The purpose of this study was to describe and evaluate a newly developed on-ice timing system for team evaluation in the sport of ice hockey. We hypothesized that this new, simple, inexpensive, timing system would prove to be highly accurate and reliable. Six adult subjects (age 30.4 ± 6.2 years) performed on ice tests of acceleration and conditioning. The performance times of the subjects were recorded using a handheld stopwatch, photocell, and high-speed (240 frames per second) video. These results were then compared to allow for accuracy calculations of the stopwatch and video as compared with filtered photocell timing that was used as the "gold standard." Accuracy was evaluated using maximal differences, typical error/coefficient of variation (CV), and intraclass correlation coefficients (ICCs) between the timing methods. The reliability of the video method was evaluated using the same variables in a test-retest analysis both within and between evaluators. The video timing method proved to be both highly accurate (ICC: 0.96-0.99 and CV: 0.1-0.6% as compared with the photocell method) and reliable (ICC and CV within and between evaluators: 0.99 and 0.08%, respectively). This video-based timing method provides a very rapid means of collecting a high volume of very accurate and reliable on-ice measures of skating speed and conditioning, and can easily be adapted to other testing surfaces and parameters. PMID:24936905

  9. 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

  10. Effect of hockey-stick-shaped molecules on the critical behavior at the nematic to isotropic and smectic-A to nematic phase transitions in octylcyanobiphenyl

    NASA Astrophysics Data System (ADS)

    Chakraborty, Anish; Chakraborty, Susanta; Das, Malay Kumar

    2015-03-01

    In the field of soft matter research, the characteristic behavior of both nematic-isotropic (N -I ) and smectic-A nematic (Sm -A N ) phase transitions has gained considerable attention due to their several attractive features. In this work, a high-resolution measurement of optical birefringence (Δ n ) has been performed to probe the critical behavior at the N -I and Sm -A N phase transitions in a binary system comprising the rodlike octylcyanobiphenyl and a laterally methyl substituted hockey-stick-shaped mesogen, 4-(3-n -decyloxy-2-methyl-phenyliminomethyl)phenyl 4-n -dodecyloxycinnamate. For the investigated mixtures, the critical exponent β related to the limiting behavior of the nematic order parameter close to the N -I phase transition has come out to be in good conformity with the tricritical hypothesis. Moreover, the yielded effective critical exponents (α', β', γ') characterizing the critical fluctuation near the Sm -A N phase transition have appeared to be nonuniversal in nature. With increasing hockey-stick-shaped dopant concentration, the Sm -A N phase transition demonstrates a strong tendency to be driven towards a first-order nature. Such a behavior has been accounted for by considering a modification of the effective intermolecular interactions and hence the related coupling between the nematic and smectic order parameters, caused by the introduction of the angular mesogenic molecules.

  11. Teardrop fracture following head-first impact in an ice hockey player: Case report and analysis of injury mechanisms

    PubMed Central

    Yue, James J.; Scott, David L.

    2016-01-01

    Background We report a case of a young male athlete who sustained a three column displaced teardrop fracture of the C5 vertebra due to a head-first impact in hockey, suffered neurapraxia, yet made full neurological recovery. This full recovery was in sharp contrast to multiple case series which reported permanent quadriplegia in the vast majority of teardrop fracture patients. We investigate the etiology and biomechanical mechanisms of injury. Methods Admission imaging revealed the teardrop fracture which consisted of: a frontal plane fracture which separated an anterior quadrilateral-shaped fragment from the posterior vertebral body; a vertical fracture of the posterior vertebral body in the sagittal plane; and incomplete fractures of the neural arch that initiated superiorly at the anterior aspect of the spinous process and left lamina adjacent to the superior facet. Epidural hematoma in the region of the C5 vertebra was observed in addition to disc and ligamentous disruptions at C4-5 and C5-6. Our patient was ultimately treated surgically with anterior fusion from C4 through C6 and subsequently with bilateral posterior fusion at C5-6. Results The injuries were caused by high-energy axial compression with the neck in a pre-flexed posture. The first fracture event consisted of the anterior vertebral body fragment being sheared off of the posterior fragment under the compression load due in part to the sagittal plane concavity of the C5 inferior endplate. The etiology of the vertical fracture of the posterior vertebral body fragment in the sagittal plane was consistent with a previously described hypothesis of the mechanistic injury events. First, the C4-5 disc height decreased under load which increased its hoop stress. Next, this increased hoop stress transferred lateral forces to the C5 uncinate processes which caused their outward expansion. Finally, the outward expansion of the uncinate processes caused the left and right sides of the vertebral body to split and spread. Evidence in support of this mechanistic event sequence was provided by the neural arch fractures which initiated superiorly, average angulation of the C5 uncinate processes, and similar well-established mechanisms causing vertical fractures at other spinal regions. Conclusions Our case study and analyses provide insight into the etiology of the specific teardrop fracture patterns observed clinically. PMID:27162711

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

    2016-01-01

    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 (x̃ = 15.5 ± CLs 15.0 and 10.0, respectively) and interceptions (x̃ = 4.0 ± CLs 4.0 and 3.0, respectively) than relegated teams (x̃ = 19.5 ± CLs 21.0 and 17.0; x̃ = 7.5 ± CLs 8.0 and 6.0, respectively). Finally, the right forwards of relegated teams demonstrated significantly fewer (P < 0.008) successful interceptions (x̃ = 4.0 ± CLs 5.0 and 4.0, respectively) than qualifying teams (x̃ = 5.0 ± CLs 6.0 and 3.0, respectively) and significantly more (P < 0.008) unsuccessful interceptions (x̃ = 5.5 ± CLs 6.0 and 4.0, respectively) than mid-table teams (x̃ = 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

  17. 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)

  18. PUCK: An Automated Prompting System for Smart Environments

    PubMed Central

    Das, Barnan; Cook, Diane J.; Schmitter-Edgecombe, Maureen; Seelye, Adriana M.

    2014-01-01

    The growth in popularity of smart environments has been quite steep in the last decade and so has the demand for smart health assistance systems. A smart home-based prompting system can enhance these technologies to deliver in-home interventions to users for timely reminders or brief instructions describing the way a task should be done for successful completion. This technology is in high demand given the desire of people who have physical or cognitive limitations to live independently in their homes. In this paper, with the introduction of the “PUCK” prompting system, we take an approach to automate prompting-based interventions without any predefined rule sets or user feedback. Unlike other approaches, we use simple off-the-shelf sensors and learn the timing for prompts based on real data that is collected with volunteer participants in our smart home test bed. The data mining approaches taken to solve this problem come with the challenge of an imbalanced class distribution that occurs naturally in the data. We propose a variant of an existing sampling technique, SMOTE, to deal with the class imbalance problem. To validate the approach, a comparative analysis with Cost Sensitive Learning is performed. PMID:25364323

  19. 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

  20. 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

  1. 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…

  2. 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...

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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…

  8. Spin-down of a rotating air hockey disk

    NASA Astrophysics Data System (ADS)

    Weidman, Patrick; Julien, Keith

    2013-11-01

    We extend the work of Weidman (APS, DFD 2008) on the steady float height of a rotating disk to formulate and solve for the unsteady behavior of spin-down to rest. A similarity reduction of the Navier-Stokes equations reduces the problem to a coupled pair of partial differential equations in space and time. For a disk of fixed radius and density, the PDE's must be solved taking into account constraints imposed by the aerodynamic torque and aerodynamic lift. Thus the full solution for the unsteady azimuthal and axial dynamics of the disk can be obtained for given initial values of disk Reynolds number R = W h / ν and dimensionless disk rotation speed S =√{ 2} Ωh / W , where h is the float height, W is the fluid levitation velocity, Ω is the disk rotation rate, and ν is the kinematic viscosity of the fluid. Integrations reveal interesting families of solutions when plotted over steady solution curves in R- S parameter space and vindicate the quasi-steady spin-down theory reported in earlier work, valid only in a restricted region of parameter space.

  9. 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.

  10. 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.

  11. 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.

  12. Particle-In-Cell Analysis of an Electric Antenna for the BepiColombo/MMO spacecraft

    NASA Astrophysics Data System (ADS)

    Miyake, Yohei; Usui, Hideyuki; Kojima, Hirotsugu

    The BepiColombo/MMO spacecraft is planned to provide a first electric field measurement in Mercury's magnetosphere by mounting two types of the electric antennas: WPT and MEFISTO. The sophisticated calibration of such measurements should be performed based on precise knowledge of the antenna characteristics in space plasma. However, it is difficult to know prac-tical antenna characteristics considering the plasma kinetics and spacecraft-plasma interactions by means of theoretical approaches. Furthermore, some modern antenna designing techniques such as a "hockey puck" principle is applied to MEFISTO, which introduces much complexity in its overall configuration. Thus a strong demand arises regarding the establishment of a nu-merical method that can solve the complex configuration and plasma dynamics for evaluating the electric properties of the modern instrument. For the self-consistent antenna analysis, we have developed a particle simulation code named EMSES based on the particle-in-cell technique including a treatment antenna conductive sur-faces. In this paper, we mainly focus on electrostatic (ES) features and photoelectron distri-bution in the vicinity of MEFISTO. Our simulation model includes (1) a photoelectron guard electrode, (2) a bias current provided from the spacecraft body to the sensing element, (3) a floating potential treatment for the spacecraft body, and (4) photoelectron emission from sunlit surfaces of the conductive bodies. Of these, the photoelectron guard electrode is a key technol-ogy for producing an optimal condition of plasma environment around MEFISTO. Specifically, we introduced a pre-amplifier housing called puck located between the conductive boom and the sensor wire. The photoelectron guard is then simulated by forcibly fixing the potential difference between the puck surface and the spacecraft body. For the modeling, we use the Capacity Matrix technique in order to assure the conservation condition of total charge owned by the entire spacecraft body. We report some numerical analyses on the influence of the guard electrode on the surrounding plasma environment by using the developed model.

  13. 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…

  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. 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

  16. 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

  17. 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…

  18. 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'

  19. 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'…

  20. 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, Verônica 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

  1. 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…

  2. Particle-In-Cell Modeling and Analysis of an Electric Antenna for the BepiColombo/MMO spacecraft

    NASA Astrophysics Data System (ADS)

    Miyake, Yohei; Usui, Hideyuki; Kojima, Hirotsugu

    2010-05-01

    The sophisticated calibration of a space-based electric antenna should be performed based on precise knowledge of electric antenna characteristics in space plasma environment. However, it is often difficult to know practical antenna characteristics considering the effects of plasma kinetics and spacecraft-plasma interactions by means of only theoretical approaches. Furthermore, some modern electric field instruments, such as the Cluster EFW instrument and MEFISTO for the BepiColombo/MMO spacecraft, are designed based on a ``hockey puck'' principle, which introduces much complexity in their overall configurations. Thus a strong demand arises regarding the establishment of a numerical method that can solve the complex configuration and plasma dynamics for evaluating the electric properties of such modern instruments. For the self-consistent antenna analysis, we have newly developed an electromagnetic (EM) particle simulation code named EMSES. The code is based on the particle-in-cell technique and also supports a treatment of inner boundaries describing spacecraft conductive surfaces. This enables us to naturally include the effects of the inhomogeneous plasma environment such as a plasma and photoelectron sheaths created around the antenna. The support of the full EM treatment is also important to apply our tool to antenna properties for not only electrostatic (ES) but also EM plasma waves. In the current study, we mainly focus on ES features and photoelectron distribution in the vicinity of the electric field instrument MEFISTO. Our simulation model includes (1) a photoelectron guard electrode, (2) a bias current provided from the spacecraft body to the sensing element, (3) a floating potential treatment for the spacecraft body, and (4) photoelectron emission from sunlit surfaces of the conductive bodies. Of these, the photoelectron guard electrode is a key technology for producing an optimal condition of plasma environment around MEFISTO. Specifically, we introduced a pre-amplifier housing called "puck" located between the conductive boom and the sensor wire. The photoelectron guard is then simulated by forcibly fixing the potential difference between the puck surface and the spacecraft body. For the modeling of the photoelectron guard electrode and the current biasing, we use the Capacity Matrix technique in order to assure the conservation condition of total charge owned by the entire spacecraft body. Our preliminary simulation run successfully showed an intended behavior of the above numerical models. By using the model, we started numerical analysis on an ES structure around MEFISTO and current-voltage characteristic of the instrument. We report some simulation results on the influence of the guard electrode on the surrounding plasma environment and the electric properties of MEFISTO.

  3. Haptic guidance of overt visual attention

    PubMed Central

    List, Alexandra; Iordanescu, Lucica; Grabowecky, Marcia; Suzuki, Satoru

    2014-01-01

    Research has shown that information accessed from one sensory modality can influence perceptual and attentional processes in another modality. Here, we demonstrated a novel crossmodal influence of haptic-shape information on visual attention. Participants visually searched for a target object (e.g., an orange) presented among distractor objects, fixating the target as quickly as possible. While searching for the target, participants held (never viewed and out of sight) an item of a specific shape in their hands. In two experiments, we demonstrated that the time for the eyes to reach a target—a measure of overt visual attention—was reduced when the shape of the held item (e.g., a sphere) was consistent with the shape of the visual target (e.g., an orange), relative to when the held shape was unrelated to the target (e.g., a hockey puck) or when no shape was held. This haptic-to-visual facilitation occurred despite the fact that the held shapes were not predictive of the visual targets’ shapes, suggesting that the crossmodal influence occurred automatically, reflecting shape-specific haptic guidance of overt visual attention. PMID:24935805

  4. 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. .

  5. Bose-Einstein condensation in dark power-law laser traps

    SciTech Connect

    Jaouadi, A.; Gaaloul, N.; Viaris de Lesegno, B.; Pruvost, L.; Telmini, M.; Charron, E.

    2010-08-15

    We investigate theoretically an original route to achieve Bose-Einstein condensation using dark power-law laser traps. We propose to create such traps with two crossing blue-detuned Laguerre-Gaussian optical beams. Controlling their azimuthal order l allows for the exploration of a multitude of power-law trapping situations in one, two, and three dimensions, ranging from the usual harmonic trap to an almost square-well potential, in which a quasihomogeneous Bose gas can be formed. The usual cigar-shaped and disk-shaped Bose-Einstein condensates obtained in a 1D or 2D harmonic trap take the generic form of a 'finger' or of a 'hockey puck' in such Laguerre-Gaussian traps. In addition, for a fixed atom number, higher transition temperatures are obtained in such configurations when compared with a harmonic trap of the same volume. This effect, which results in a substantial acceleration of the condensation dynamics, requires a better but still reasonable focusing of the Laguerre-Gaussian beams.

  6. 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…

  7. 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

  8. 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

  9. 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.

  10. Insensitive HE EOS

    SciTech Connect

    Ree, F.H.; Viecelli, J.; van Thiel, M.

    1997-12-01

    A typical insensitive high explosive such as LX-17 has a large carbon-content and produces hydrogen fluoride (HF) as a detonation product. It is also characterized by slow energy release as indicated by a large curvature of the detonation front. We analyze these new physics issues which are needed to predict the performance of a insensitive high explosive. (U)

  11. 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.

  12. 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…

  13. Meniscus Tears

    MedlinePlus

    ... common sports injury, particularly in contact sports like football and hockey. Meniscus tears can range from minor ... knee while playing a contact sport, such as football, hockey, or rugby, where the knee may be ...

  14. 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.

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

    NASA Technical Reports Server (NTRS)

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

    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.

  16. 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.

  17. 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.'

  18. 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.

  19. Protect Your Eyes When You Exercise

    MedlinePlus

    ... 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 ...

  20. Safety Tips: Baseball (For Parents)

    MedlinePlus

    ... Sports Medicine Center Safety Tips: Hockey Safety Tips: Basketball Competitive Sports: Helping Kids Play it Cool Preventing Children's Sports Injuries Kids Ask Cal Taking the Pressure Off Sports ...

  1. 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…

  2. 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…

  3. 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…

  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. 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)

  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. 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…

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Insensitive fuze train for high explosives

    DOEpatents

    Cutting, Jack L.; Lee, Ronald S.; Von Holle, William G.

    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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. How to Succeed in Business.

    ERIC Educational Resources Information Center

    Arnold, Josh

    1996-01-01

    Entrepreneurship is helping balance the budget for the Gloucester, Massachusetts, schools. The school district has taken over management of an indoor ice hockey rink, is running concessions on two city beaches, and started its own school bus company. (MLF)

  2. Winter Sports for People Living With Paralysis

    MedlinePlus

    ... hockey is played by people who use their arms to propel themselves by digging picks on the ... funds sports wheelchairs, handcycles, mono-skis and sports prosthetics, as well as expenses for training and competition. ...

  3. Your Eyes

    MedlinePlus

    ... a blue hat while he tosses an orange basketball. Sometimes someone's eyeball shape makes it difficult for ... science lab, or art. Wear eye protection when playing racquetball, hockey, skiing, or other sports that could ...

  4. Sports Injuries to the Foot and Ankle

    MedlinePlus

    ... from repetitive play. For more information on the injury risk factors while playing your favorite sport, see the topics listed below or read the article, Foot Health Facts for Athletes . Baseball Basketball Field Hockey Football Injuries Golf Injuries Lacrosse Rugby ...

  5. Congenital Heart Defects and Physical Activity

    MedlinePlus

    ... Team or court sports such as basketball, soccer, football, tennis, squash and volleyball are also aerobic activities. ... year after surgery. Intensely physical sports such as football, boxing or hockey may increase the chance for ...

  6. Anterior Cruciate Ligament (ACL) Injuries

    MedlinePlus

    ... get ACL injuries usually play contact sports (like football) or sports that feature swift, abrupt movements such ... the things you love — like running or playing football, field hockey, or softball — can be frustrating. Recovering ...

  7. Medial Collateral Ligament (MCL) Injuries

    MedlinePlus

    ... torn MCL tend to play contact sports, like football and soccer. More severe injuries happen when the ... the things you love — like running or playing football, field hockey, or softball — can be frustrating. If ...

  8. 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)

  9. 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)

  10. 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. ...

  11. Dealing with Peer Pressure

    MedlinePlus

    ... challenging decisions. Some don't have a clear right or wrong answer — like should you play soccer or field hockey? Other decisions involve serious moral questions, like whether to cut class, try cigarettes , ...

  12. 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

  13. 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)

  14. Quadriceps Contusion

    MedlinePlus

    ... it both tear. Quadriceps contusions are common in sports that involve a lot of direct contact, such ... and hockey. They're also a risk in sports where there's a chance of collisions, like soccer ...

  15. 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…

  16. Reviews

    NASA Astrophysics Data System (ADS)

    2004-03-01

    WEB WATCH (204) Try unearthing some interesting information about archaeology BOOK REVIEWS (206) Teaching and assessing practical skills Book Review: Learn to drive with Sir Isaac Newton DVD REVIEW (207) Bring some sunshine into the classroom EQUIPMENT REVIEWS (208) Robust air puck takes a kicking Flowlog offers sensing options plus multimode datalogging Mastering Chladni figures takes practice but it offers surprises

  17. 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.

  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. 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)

  20. 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)

  1. 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

  2. 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.

  3. 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)

  4. 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…

  5. 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.

  6. 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…

  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. 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.

  9. Modeling of the Jack Rabbit Series of Experiments with a temperature-based reactive burn mode

    NASA Astrophysics Data System (ADS)

    Desbiens, Nicolas; Sorin, Remy; Dubois, Vincent

    2015-06-01

    A reactive burn model based on shocked explosive temperature has been presented at the previous joint AIRAPT/APS-SCCM in Seattle. It has been shown that the temperature of the unburnt shocked explosive is a good candidate to drive rate laws of decomposition. Such models are able to reproduce the evolution of the sensitivity of explosives with porosity. They also predict a drastic reduction of the reactivity in the case of multi-shock compression without any bolt-on desensitization model. In this work, we apply our temperature-based reactive burn model to the data of the Jack Rabbit Series of Experiments. Indeed, these experiments dedicated to the study of detonation wave corner turning and shock desensitization in LX-17 are harsh tests for reactive burn models. Details of our model together with preliminary results will be shown.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Chiropractic management of a patient with postoperative lateral retinacular release using a multimodal approach: a case report

    PubMed Central

    Solecki, Thomas J.; Hostnik, Kurt D.

    2012-01-01

    Objective The purpose of this case report is to describe a chiropractic rehabilitation program for a patient with postsurgical lateral retinaculum release. Clinical Features A 26-year-old male ice hockey goalie presented 1 month after having lateral retinaculum release surgery for his left knee with residual mild discomfort and edema in his left knee. Intervention and Outcome The patient was treated using a multimodal approach of both passive and active chiropractic care focusing on the restoration of full range of motion, increased proprioception, balance, strength, and endurance to return the patient to competitive ice hockey. Conclusion This case study demonstrated that, after 14 weeks of care, the patient was able to return to ice hockey training with no residual symptoms. PMID:22942841

  1. 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.

  2. Effects of the guard electrode on the photoelectron distribution around an electric field sensor

    NASA Astrophysics Data System (ADS)

    Miyake, Y.; Usui, H.; Kojima, H.

    2011-05-01

    We have developed a numerical model of a double-probe electric field sensor equipped with a photoelectron guard electrode for the particle-in-cell simulation. The model includes typical elements of modern double-probe sensors on, e.g., BepiColombo/MMO, Cluster, and THEMIS spacecraft, such as a conducting boom and a preamplifier housing called a puck. The puck is also used for the guard electrode, and its potential is negatively biased by reference to the floating spacecraft potential. We apply the proposed model to an analysis of an equilibrium plasma environment around the sensor by assuming that the sun illuminates the spacecraft from the direction perpendicular to the sensor deployment axis. As a simulation result, it is confirmed that a substantial number of spacecraft-originating photoelectrons are once emitted sunward and then fall onto the puck and sensing element positions. In order to effectively repel such photoelectrons coming from the sun direction, a potential hump for electrons, i.e., a negative potential region, should be created in a plasma region around the sunlit side of the guard electrode surface. The simulation results reveal the significance of the guard electrode potential being not only lower than the spacecraft body but also lower than the background plasma potential of the region surrounding the puck and the sensing element. One solution for realizing such an operational condition is to bias the guard potential negatively by reference to the sensor potential because the sensor is usually operated nearly at the background plasma potential.

  3. Living history biography

    SciTech Connect

    Puck, T.T.

    1994-11-15

    A living history biography is presented of Theodore T. Puck. This history is intimately involved with the progress towards mapping of the human genome through research at the forefront of molecular cytogenetics. A review of historical research aims such as human genetics studies based on somatic cells, isolation of mutants as genetic markers, complementation analysis, gene mapping and the measurement of mutation is presented. 37 refs., 4 figs.

  4. 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

  5. 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…

  6. 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…

  7. 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

  8. 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…

  9. 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…

  10. 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)

  11. Athletes' Evaluations of Their Head Coach's Coaching Competency

    ERIC Educational Resources Information Center

    Myers, Nicholas D.; Feltz, Deborah L.; Maier, Kimberly S.; Wolfe, Edward W.; Reckase, Mark D.

    2006-01-01

    This study provided initial validity evidence for multidimensional measures of coaching competency derived from the Coaching Competency Scale (CCS). Data were collected from intercollegiate men's (n = 8) and women's (n = 13) soccer and women's ice hockey teams (n = 11). The total number of athletes was 585. Within teams, a multidimensional…

  12. Congress Assesses Climate Change Paleodata

    NASA Astrophysics Data System (ADS)

    Bierly, Eugene W.

    2006-08-01

    The `hockey stick' graph of surfacetemperature change overthe past millennium and implicationsfor climate change assessments wasthe subject of two hearings held by the U.S.House of Representatives Energy and CommerceSubcommittee on Oversight andInvestigations, on 19 and 27 July. These hearingsmarked only the second time that thecommittee has discussed climate issuessince George W. Bush became president.

  13. 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

  14. 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,…

  15. 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…

  16. Epilepsy and athletics.

    PubMed

    Cantu, R V; Cantu, R

    1998-01-01

    This article reviews the debate regarding epileptic patients and their participation in sports, particularly contact (i.e., basketball, soccer, baseball) and collision (i.e., football, rugby, hockey) sports. Epilepsy is defined and described, as well as the dangers and benefits of exercise to the epileptic patient, including participation in athletic competition. PMID:9475971

  17. 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…

  18. 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…

  19. 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…

  20. 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,

  1. 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…

  2. 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

  3. 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…

  4. 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…

  5. 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…

  6. 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

  7. 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

  8. 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…

  9. 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)

  10. 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)

  11. 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…

  12. 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

  13. 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.

  14. 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…

  15. "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…

  16. 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,…

  17. The Impact of Athletic Facilities on the Recruitment of Potential Student-Athletes

    ERIC Educational Resources Information Center

    Schneider, Ray; Messenger, Steve

    2012-01-01

    Purpose: This study examined the impact that athletic facilities and other college choice factors have on the recruitment of student-athletes to play Division I college hockey compared to the influence of other college choice factors. Although athletic facilities and their seeming importance in the recruitment of top level student-athletes are…

  18. 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…

  19. 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

  20. "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

  1. 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

  2. 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. |

  3. 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

  4. Violence in Sports.

    ERIC Educational Resources Information Center

    Cooper, Donald L.

    Increasing violence in sports is deplored, and a warning is issued on an apparent trend toward antisocial behavior. Contact sports such as hockey and football are cited as typically engendering aggression among athletes, but spectator sports (boxing, car racing, basketball, and baseball) are also singled out as eliciting increasing violence on the…

  5. 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…

  6. 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…

  7. Sports, Youth and Character: A Critical Survey. CIRCLE Working Paper 44

    ERIC Educational Resources Information Center

    Fullinwider, Robert K.

    2006-01-01

    Roughly forty million boys and girls between the ages of 5 and 18 take part in organized athletic activities, most of which are not school-based. Boys and girls play in sports as varied as swimming, baseball, soccer, wrestling, and field hockey. The great majority participate in "recreational" leagues in which teams enroll all-comers, compete…

  8. 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…

  9. 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…

  10. 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

  11. 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,…

  12. 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

  13. 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…

  14. 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…

  15. 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.

  16. 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

  17. Eccentric utilization ratio: effect of sport and phase of training.

    PubMed

    McGuigan, Michael R; Doyle, Timothy L A; Newton, Michael; Edwards, Dylan J; Nimphius, Sophia; Newton, Robert U

    2006-11-01

    The eccentric utilization ratio (EUR), which is the ratio of countermovement jump (CMJ) to static jump (SJ) performance, has been suggested as a useful indicator of power performance in athletes. The purpose of the study was to compare the EUR of athletes from a variety of different sports and during different phases of training. A total of 142 athletes from rugby union, Australian Rules Football, soccer, softball, and field hockey were tested. Subjects performed both CMJ and SJ on a force plate integrated with a position transducer. The EUR was measured as the ratio of CMJ to SJ for jump height and peak power. The rugby union, Australian Rules Football, and hockey athletes were tested during off-season and preseason to provide EUR data during different phases of training. For men, EUR for soccer, Australian Rules Football, and rugby was greater than softball (effect size range, 0.83-0.92). For women, EUR for soccer was greater than field hockey and softball (0.86- 1.0). There was a significant difference between the jump height and peak power method for the Australian Rules Football, rugby, and field hockey tests conducted preseason (p < 0.05). For field hockey, there was a significant increase in EUR from off-season to preseason. Athletes in sports such as soccer, rugby union, and Australian Rules Football appear to have higher EUR values, which reflects the greater reliance on stretch shortening activities in these sports. It does appear that EUR can be used to track changes in training with the values significantly increasing from off-season to preseason. The EUR provides the practitioner with information about the performance of athletes and appears to be sensitive to changes in the type of training being undertaken. PMID:17194252

  18. Plutonium Immobilization Project Phase 1 Cold Pour Test

    SciTech Connect

    Smith, M.E.

    2000-03-02

    This paper describes the Phase 1 scoping tests and results. The Plutonium Immobilization Project will disposition excess weapons grade plutonium. It uses the can-in-canister approach that involves placing plutonium containing ceramic pucks in sealed cans that are then placed into Defense Waste Processing Facility canisters. These canisters are subsequently filled with high-level radioactive waste glass. This process puts the plutonium in a stable form and makes it unattractive for reuse. A cold (non-radioactive) test program was planned to develop and verify the baseline design for the canister and internal hardware. This paper describes the Phase 1 scoping tests and results.

  19. 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.

  20. The Piece Wise Linear Reactive Flow Model

    SciTech Connect

    Vitello, P; Souers, P C

    2005-08-18

    For non-ideal explosives a wide range of behavior is observed in experiments dealing with differing sizes and geometries. A predictive detonation model must be able to reproduce many phenomena including such effects as: variations in the detonation velocity with the radial diameter of rate sticks; slowing of the detonation velocity around gentle corners; production of dead zones for abrupt corner turning; failure of small diameter rate sticks; and failure for rate sticks with sufficiently wide cracks. Most models have been developed to explain one effect at a time. Often, changes are made in the input parameters used to fit each succeeding case with the implication that this is sufficient for the model to be valid over differing regimes. We feel that it is important to develop a model that is able to fit experiments with one set of parameters. To address this we are creating a new generation of models that are able to produce better fitting to individual data sets than prior models and to simultaneous fit distinctly different regimes of experiments. Presented here are details of our new Piece Wise Linear reactive flow model applied to LX-17.

  1. On the Nature of Variations in Density and Composition within TATB-based Plastic Bonded Explosives

    SciTech Connect

    Kinney, J H; Willey, T M; Overturf, G

    2006-06-27

    Initiation of insensitive high explosives is affected by porosity in the 100 nm to micron size range. It is also recognized that as-pressed plastic bonded explosives (PBX) are heterogeneous in composition and density at much coarser length scale (10 microns-100 microns). However, variations in density and composition of these explosives have been poorly characterized. Here, we characterize the natural variations in composition and density of TATB-based PBX LX-17 with synchrotron radiation tomography and ultra small angle x-ray scattering. Large scale variations in composition occur as a result of binder enrichment at the prill particle boundaries. The pore fraction is twice as high in the prill particle as in the boundary. The pore distribution is bimodal, with small pores of 50-100 nm in radius and a broader distribution of pores in the 0.5-1.5 micron size range. The higher pore density within the prill particle is attributed to contact asperities between the crystallites that might inhibit complete consolidation and binder infiltration.

  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. Molten salt destruction as an alternative to open burning of energetic material wastes

    SciTech Connect

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

    1994-07-05

    LLNL has built a small-scale (about 1 kg/hr throughput unit to test the destruction of energetic materials using the Molten Salt Destruction (MSD) process. We have modified the unit described in the earlier references to inject energetic waste material continuously into the unit. In addition to the HMX, other explosives we have destroyed include RDX, PETN, ammonium picrate, TNT, nitroguanadine, and TATB. We have also destroyed a liquid gun propellant comprising hydroxyl ammonium nitrate, triethanolammonium nitrate and water. In addition to these pure components, we have destroyed a number of commonly used formulations, such as LX-10 (HMX/Viton), LX-16 (PETN/FPC461, LX-17 (TATB/Kel F), and PBX-9404 (HMX)/CEF/Nitro cellulose). Our experiments have demonstrated that energetic materials can be safely and effectively treated by MSD.We have also investigated the issue of steam explosions in molten salt units, both experimentally and theoretically, and concluded that steam explosions can be avoided under proper design and operating conditions. We are currently building a larger unit (nominal capacity 5 kg/hr,) to investigate the relationship between residence time, temperature, feed concentration and throughputs, avoidance of back-burn, a;nd determination of the products of combustion under different operating conditions.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. Dose-response analysis of infants prenatally exposed to methyl mercury: An application of a single compartment model to single-strand hair analysis

    SciTech Connect

    Cox, C.; Clarkson, T.W.; Marsh, D.O.; Amin-Zaki, L.; Tikriti, S.; Myers, G.G. )

    1989-08-01

    A new method of estimating fetal exposure is used in a dose-response analysis of data from the 1971 outbreak of methyl mercury poisoning in rural Iraq. An X-ray fluorescence instrument for the measurement of single strands of human hair was employed to obtain longitudinal profiles recapitulating fetal exposure. Logit and hockey-stick models as well as nonparametric smoothing are used to describe data on delayed development and central nervous system abnormality.

  13. 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.

  14. [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

  15. Helmet removal in head and neck trauma.

    PubMed

    Roberts, W O

    1998-07-01

    When an ice hockey player hits the boards head-first after a hard body check or a football defensive back doesn't get up after a head-on tackle, the initial response is critical. If the player is unconscious or not breathing, it may be necessary to remove his or her helmet to access the airway. Helmet removal requires a careful, methodical approach to avoid compounding a suspected injury to the spinal cord. PMID:20086837

  16. THE USE OF ACETIC ACID IONTOPHORESIS IN THE MANAGEMENT OF A SOFT TISSUE INJURY

    PubMed Central

    Ebaugh, David

    2010-01-01

    Background: Contusions are common injuries that occur in athletics. If repeated, complications like myositis ossificans can occur. This case describes the examination and treatment of an athlete with an acute soft tissue injury. Objective: To describe the treatment approach used with a hockey player who sustained a soft tissue injury in his upper extremity. Case Description: A 19 year old male sustained a soft tissue injury to his upper arm while playing hockey. The athlete complained of pain rated a 2-3 out of 10. He had a well circumscribed, firm, 8 by 5 centimeter palpable mass present along the lateral arm, and was able to passively flex his elbow from 56° to 135°, demonstrating a 56° loss of elbow extension. Functionally, he was able to perform most activities of daily living, but he was unable to play hockey. Over 29 days, the athlete was treated one time with pulsed ultrasound and ice and nine times with iontophoresis using a 2% acetic acid solution. Additionally, the athlete performed pain-free active range of motion exercises for the elbow. Outcome: Following treatment, the athlete's pain resolved, the palpable mass disappeared, and his passive range of motion at the elbow was 0° to 135°. Most importantly, the athlete was able to resume playing hockey. Discussion: Acetic acid iontophoresis may be a successful intervention for soft tissue injuries of the upper extremity. In this case, it appeared helpful in decreasing the athlete's impairments and contributed to quicker resumption of all functional activities in less time than previously reported in the literature using traditional treatment interventions. PMID:21655380

  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. 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

  19. 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.

  20. 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.

  1. 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.

  2. Geology of the Uranian satellites

    NASA Technical Reports Server (NTRS)

    Croft, S. K.; Soderblom, L. A.

    1991-01-01

    A geological analysis of six of the Uranus satellites observed in detail by Voyager 2 is presented. All of the satellites except the smallest, Puck, show evidence of cryovolcanic resurfacing: global on the largest four satellites, local in the spectacular coronae on Miranda. The cryovolcanic materials exhibit a range of albedos and morphologies, which are interpreted to reflect a variety of compositions and conditions of eruption at least as complex as those which occur on earth. Eruptions are predominantly large fissure flows that produce extensive flood deposits. Possible evidence of small circular vents and cryoclastic volcanic activity is seen on Miranda and Ariel. All of the satellites except Puck also have extensive sets of grabens and riftlike canyons that show remarkable similarity of pattern: intersection sets trending roughly NW-SW and NE-SW in the low latitudes grading into E-W trends near the poles. As a group, the Uranian satellites are somewhat more active geologically than similarly sized Saturnian satellites.

  3. 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 sensor’s 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.

  4. 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

  5. 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.

  6. 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.

  7. 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 Site’s 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.

  8. 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.

  9. Linear Synchronous Motor Repeatability Tests

    SciTech Connect

    Ward, C.R.

    2002-10-18

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility.

  10. Localized surface phonon polariton resonances in polar gallium nitride

    NASA Astrophysics Data System (ADS)

    Feng, Kaijun; Streyer, William; Islam, S. M.; Verma, Jai; Jena, Debdeep; Wasserman, Daniel; Hoffman, Anthony J.

    2015-08-01

    We demonstrate the excitation of localized surface phonon polaritons in an array of sub-diffraction pucks fabricated in an epitaxial layer of gallium nitride (GaN) on a silicon carbide (SiC) substrate. The array is characterized via polarization- and angle-dependent reflection spectroscopy in the mid-infrared, and coupling to several localized modes is observed in the GaN Reststrahlen band (13.4-18.0 μm). The same structure is simulated using finite element methods and the charge density of the modes are studied; transverse dipole modes are identified for the transverse electric and magnetic polarizations and a quadrupole mode is identified for the transverse magnetic polarization. The measured mid-infrared spectrum agrees well with numerically simulated spectra. This work could enable optoelectronic structures and devices that support surface modes at mid- and far-infrared wavelengths.

  11. 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

  12. 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.

  13. 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.

  14. Seasonal distribution of metals in vertical and horizontal profiles of sheltered and exposed beaches on Polish coast.

    PubMed

    Bigus, Katarzyna; Astel, Aleksander; Niedzielski, Przemysław

    2016-05-15

    The distribution of alkali and heavy metals in coastal sediments of three Polish beaches was assessed. In all locations there are sandy beaches of different characteristics according to the anthropogenic impact and degree of sheltering. Core sediments collected in Czołpino and Ustka were characterized by the highest concentration of Cd, Ag, Ba, and Al, Cu, Cr, Bi, Na, respectively. Among the alkaline metals core sediments were the most abundant with Ca, Bi, Mg and Na, presenting almost stable decreasing order in all beaches. The majority of dredge material collected can be classified as light or trace contaminated by Cr, Cu, Zn, Cd and Hg. An abundance of mineralogical components in core sediments in Ustka increases in Summer and Autumn, while in Puck is stable throughout the year. The content of studied metals in core sediments collected in three Polish beaches changes both in the vertical and horizontal profiles of the beach. PMID:26975611

  15. 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.

  16. 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

  17. On the influence of particle morphology on the post-impact ballistic response of ceramic armour materials

    NASA Astrophysics Data System (ADS)

    Hameed, Amer; Appleby-Thomas, Gareth; Wood, David; Jaansalu, Kevin

    2015-06-01

    Recent studies have shown evidence that the ballistic-resistance of fragmented (comminuted) ceramics is independent of the original strength of the material. In particular, experimental investigations into the ballistic behaviour of such fragmented ceramics have indicated that this response is correlated to shattered ceramic morphology. This suggests that careful control of ceramic microstructure - and therefore failure paths - might provide a route to optimise post-impact ballistic performance, thereby enhancing multi-hit capability. In this study, building on previous in-house work, ballistic tests were conducted using pre-formed `fragmented-ceramic' analogues based around three morphologically differing (but chemically identical) alumina feedstock materials compacted into target `pucks. In an evolution of previous work, variation of target thickness provided additional insight into an apparent morphology-based contribution to ballistic response.

  18. An Automated, High-Throughput System for GISAXS and GIWAXS measurements of thin films

    NASA Astrophysics Data System (ADS)

    Schaible, Eric; Jimenez, Jessica; Church, Matthew; Lim, Eunhee; Stewart, Polite; Hexemer, Alexander

    Grazing incidence small-angle X-ray scattering (GISAXS) and grazing incidence wide-angle X-ray scattering (GIWAXS) are important techniques for characterizing thin films. In order to meet rapidly increasing demand, the SAXSWAXS beamline at the Advanced Light Source (beamline 7.3.3) has implemented a fully automated, high-throughput system to conduct SAXS, GISAXS and GIWAXS measurements. An automated robot arm transfers samples from a holding tray to a measurement stage. Intelligent software aligns each sample in turn, and measures each according to user-defined specifications. Users mail in trays of samples on individually barcoded pucks, and can download and view their data remotely. Data will be pipelined to the NERSC supercomputing facility, and will be available to users via a web portal that facilitates highly parallelized analysis. Support provided by the Joint Center for Artificial Photosynthesis (JCAP).

  19. 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.

  20. 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

  1. Student Understanding of Single Particle Dynamics.

    NASA Astrophysics Data System (ADS)

    Lawson, Ronald Aaron

    This dissertation reports the findings of an investigation of student understanding of the concept of force, the connection between force and motion, and the work-energy and impulse -momentum relations. The operational criterion for understanding used in this investigation was the ability of a student to apply a concept to the analysis of a simple observed motion. About one hundred physics students enrolled at the University of Washington participated in the study. Included were students from the first quarter of the non-calculus physics sequence and students from both regular and honors sections of the first quarter of the calculus-based physics sequence. The study also included a group of inservice middle and high school science teachers and students from a special preparatory physics course for minority students aspiring to careers in the health sciences, engineering and other science-related fields. Individual demonstration interviews were the primary data source in the study. During these interviews, students observed, described, and analyzed motions of one or more frictionless pucks that moved on a smooth level surface. The students were asked to modify the motion of the pucks through the use of a device which applied a force that could be varied in both magnitude and direction. The data obtained in this study suggest that students have difficulty applying their knowledge of physics to the analysis of simple observed motions. Students revealed a variety of conceptions of force and a number of beliefs about the connection between force and motion that are at variance with the Law of Inertia and the Second Law of Motion. Students who had recently studied the work -energy and impulse-momentum relations had considerable difficulty applying these relations to the analysis of a simple observed motion.

  2. High performance batch production of LREBa 2Cu 3O y using novel thin film Nd-123 seed

    NASA Astrophysics Data System (ADS)

    Muralidhar, M.; Suzuki, K.; Fukumoto, Y.; Ishihara, A.; Tomita, M.

    2011-11-01

    A batch production for fabrication of LREBa 2Cu 3O y (LRE: Sm, Gd, NEG) “LRE-123” pellets are developed in air and Ar-1% O 2 using a novel thin film Nd-123 seeds grown on MgO crystals. The SEM and XRD results conformed that the quality and orientation of the seed crystals are excellent. On the other hand, new seeds can withstand temperatures >1100 °C, as a result, the cold seeding process was applied even to grow Sm-123 material in Air. The trapped field observed in the best 45 mm single-grain puck of Gd-123 was in the range of 1.35 T and 0.35 T at 77.3 K and 87.3 K, respectively. The average trapped field at 77.3 K in the 24 mm diameter NEG-123 samples batch lies between 0.9 and 1 T. The maximum trapped field of 1.2 T was recorded at the sample surface. Further, the maximum trapped field of 0.23 T at 77 K was recorded in a sample with 16 mm diameter of Sm-123 with 3 mol% BaO 2 addition. As a result we made more then 130 single grain pucks within a couple of months. Taking advantage of the single grain batch processed material, we constructed self-made chilled levitation disk, which was used on the open day of railway technical research Institute. More then 150 children stood on the levitation disk and revel the experience of levitation. The present results prove that a high-performance good-quality class of LREBa 2Cu 3O y material can be made by using a novel thin film Nd-123 seeds.

  3. 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.

  4. 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.

  5. 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.

  6. Fabrication and properties of CNTs reinforced polymeric matrix nanocomposites for sports applications

    NASA Astrophysics Data System (ADS)

    Rasheed, A.; Khalid, F. A.

    2014-06-01

    The polymeric matrix composites have found extensive applications in sports because of high strength to weight ratio, ease of processing, and longer life. This work was carried out to study the properties of different sections of composite field hockey sticks and the influence of carbon nanotubes on their properties. The samples were fabricated by compression molding process. The increase in mechanical properties by the incorporation of carbon nanotubes is correlated with the process parameters to consider enhancement in the overall performance of the stick sections.

  7. 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

  8. 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

  9. 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

  10. 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

  11. Potential Long-Term Consequences of Concussive and Subconcussive Injury.

    PubMed

    Huber, Bertrand R; Alosco, Michael L; Stein, Thor D; McKee, Ann C

    2016-05-01

    Repeated concussive and subconcussive trauma is associated with the later development of chronic traumatic encephalopathy (CTE), a neurodegenerative disease associated with clinical symptoms in multiple domains and a unique pattern of pathologic changes. CTE has been linked to boxing and American football; CTE has also been identified in soccer, ice hockey, baseball, rugby, and military service. To date, most large studies of CTE have come from enriched cohorts associated with brain bank donations for traumatic brain injury, although several recent studies re-examining neurodegenerative disease brain banks suggest that CTE is more common than is currently appreciated. PMID:27154859

  12. "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

  13. 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

  14. 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.

  15. Exercise-related transient abdominal pain secondary to median arcuate ligament syndrome: a case report.

    PubMed

    Haskins, Ivy N; Harr, Jeffrey N; Brody, Fred

    2016-07-01

    Exercise-related transient abdominal pain is a common entity in young athletes. An uncommon aetiology of this type of pain is median arcuate ligament syndrome. This article details an 18-year-old field hockey player who presented with a 1-year history of exercise-related transient abdominal pain. Despite a trial of preventative strategies, the patient's pain persisted, prompting surgical intervention. Following a laparoscopic median arcuate ligament release, the patient's symptoms resolved. Therefore, when exercise-related transient abdominal pain persists despite precautionary measures, median arcuate ligament syndrome should be considered. PMID:26542078

  16. Rumination and Performance in Dynamic, Team Sport.

    PubMed

    Roy, Michael M; Memmert, Daniel; Frees, Anastasia; Radzevick, Joseph; Pretz, Jean; Noël, Benjamin

    2015-01-01

    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

  17. Groin Injuries in Sports Medicine

    PubMed Central

    Tyler, Timothy F.; Silvers, Holly J.; Gerhardt, Michael B.; Nicholas, Stephen J.

    2010-01-01

    Context: An in-season groin injury may be debilitating for the athlete. Proper diagnosis and identification of the pathology are paramount in providing appropriate intervention. Furthermore, an adductor strain that is treated improperly can become chronic and career threatening. Any one of the 6 muscles of the adductor muscle group can be involved. The degree of injury can range from a minor strain (grade 1), where minimal playing time is lost, to a severe strain (grade 3), in which there is complete loss of muscle function. Persistent groin pain and muscle imbalance may lead to athletic pubalgia. Evidence Acquisition: Relevant studies were identified through a literature search of MEDLINE and the Cochrane database from 1990 to 2009, as well as a manual review of reference lists of identified sources. Results: Ice hockey and soccer players seem particularly susceptible to adductor muscle strains. In professional ice hockey and soccer players throughout the world, approximately 10% to 11% of all injuries are groin strains. These injuries have been linked to hip muscle weakness, a previous injury to that area, preseason practice sessions, and level of experience. This injury may be prevented if these risk factors are addressed before each season. Conclusion: Despite the identification of risk factors and strengthening intervention for athletes, adductor strains continue to occur throughout sport. If groin pain persists, the possibility of athletic pubalgia needs to be explored, because of weakening or tears in the abdominal wall muscles. A diagnosis is confirmed by exclusion of other pathology. PMID:23015943

  18. Health effects resulting from nitrogen dioxide exposure in an indoor ice arena.

    PubMed

    Rosenlund, M; Bluhm, G

    1999-01-01

    We investigated an outbreak of acute respiratory illness among adolescent ice-hockey players in an indoor ice arena in Stockholm that had a propane-powered ice-resurfacing machine. We administered questionnaires to all players, as well as to a reference group that had played ice hockey in indoor arenas with electric ice-resurfacing machines. In the exposed group, 55 subjects (55.6%) experienced acute respiratory symptoms, compared with 4 (7.1%) in the reference group (relative risk = 7.8; 95% confidence interval = 3.0, 20.3). The risk for pulmonary symptoms increased as time spent on the ice increased. Levels of nitrogen dioxide up to 2358 microg/m3 (1250 ppb) were detected during simulated conditions of the incident. The most likely cause of the outbreak was the high level of nitrogen dioxide that resulted from poor ventilation and a malfunctioning ice-resurfacing machine. Propane-fueled ice-resurfacing machines should not be used in indoor ice arenas. PMID:10025417

  19. Paths to expertise in portuguese national team athletes.

    PubMed

    Leite, Nuno; Baker, Joseph; Sampaio, Jaime

    2009-01-01

    The purpose of this study was to identify the quantity and type of sporting activities undertaken by expert team sport athletes in the earlier stages of the long- term athlete development. Experts in roller-hockey (n = 19), volleyball (n = 14), soccer (n = 42) and basketball (n = 37) provided detailed information about the sporting activities they undertook throughout their careers. Results showed considerable variation between and within sports; however, generally, athletes began participating in sports between 6 and 10 years of age. The pattern of participation in specific and non-specific (team, individual and combat) sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. Our results suggest that involvement in multiple sports during early stages of development is an alternative to early specialization and add further evidence of the complexity of skill acquisition in sport. Key pointsAlthough most athletes began sport participation between 6 and 10 years of age, there was significant variation across groups suggesting considerable flexibility in the pathways to expertise.The path to expertise in volleyball was clearly distinct from the paths of basketball, soccer and roller-hockey.There is a considerable involvement in sports other than the athlete's primary sport, suggesting early specialization is not required for these sports.The pattern of participation in specific and non-specific sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. PMID:24149598

  20. 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

  1. 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., January–March), 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

  2. 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.

  3. 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.

  4. Does size of one's community affect likelihood of being drafted into the NHL? Analysis of 25 years of data.

    PubMed

    Baker, Joseph; Shuiskiy, Kasania; Schorer, Jörg

    2014-01-01

    The consistency of community size effects in North American contexts but not elsewhere, reinforces the notion that the effect is driven by socio-cultural factors specific to the country under examination. In order to identify and understand the various forces driving the community size effect, it is important to determine whether the effect has changed over time. Stability or instability over time would assist researchers in identifying the specific socio-cultural mechanisms driving these effects. This study compared the influence of community size on the likelihood of being drafted into the National Hockey League (NHL) among Canadian ice hockey players drafted to play in the NHL between 1985 and 2009. Although there was some variability over the timespan examined, most notably in communities with between 250,000 and 499,999 inhabitants and over 1,000,000 inhabitants, trends were generally stable over time, suggesting that the socio-cultural mechanisms may have also been relatively stable, although further work is necessary to confirm this assumption. PMID:24738661

  5. Comparison of the home advantage in nine different professional team sports in Spain.

    PubMed

    Gómez, Miguel A; Pollard, Richard; Luis-Pascual, Juan-Carlos

    2011-08-01

    Home advantage is a well-established phenomenon in many sports. The present study is unique in that it includes different sports analysed in the same country, at the same level of competition, and over the same time period. Nine team sports from Spain were included: baseball, basketball, handball, indoor soccer, roller hockey, rugby, soccer, volleyball, and water polo. Data for five seasons (2005-2006 to 2009-2010) were obtained, totaling 9,472 games. The results confirmed the existence of home advantage in all nine sports. There was a statistically significant difference between the sports; home advantage was highest in rugby (67.0%), and lowest in volleyball (55.7%), water polo (56.2%), and roller hockey (58.3%). The design of the study controlled for some of the likely causes of home advantage, and the results suggested that the high home advantage for rugby was likely a reflection of the continuous, aggressive, and intense nature of the sport. PMID:21987916

  6. Paths to Expertise in Portuguese National Team Athletes

    PubMed Central

    Leite, Nuno; Baker, Joseph; Sampaio, Jaime

    2009-01-01

    The purpose of this study was to identify the quantity and type of sporting activities undertaken by expert team sport athletes in the earlier stages of the long- term athlete development. Experts in roller-hockey (n = 19), volleyball (n = 14), soccer (n = 42) and basketball (n = 37) provided detailed information about the sporting activities they undertook throughout their careers. Results showed considerable variation between and within sports; however, generally, athletes began participating in sports between 6 and 10 years of age. The pattern of participation in specific and non-specific (team, individual and combat) sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. Our results suggest that involvement in multiple sports during early stages of development is an alternative to early specialization and add further evidence of the complexity of skill acquisition in sport. Key points Although most athletes began sport participation between 6 and 10 years of age, there was significant variation across groups suggesting considerable flexibility in the pathways to expertise. The path to expertise in volleyball was clearly distinct from the paths of basketball, soccer and roller-hockey. There is a considerable involvement in sports other than the athlete’s primary sport, suggesting early specialization is not required for these sports. The pattern of participation in specific and non-specific sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. PMID:24149598

  7. 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

  8. 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.

  9. Solving the energy dilemma at Seven Bridges Ice Arena

    SciTech Connect

    Louria, D.

    1996-08-01

    Seven Bridges Ice Arena with three ice skating rinks is among the largest ice skating facilities in the US. A complete fitness center, pro shop, second level observation gallery, restaurant, aerobics room, dance studio and children`s play room round out the 120,000 ft{sup 2} (11,215 m{sup 2}) world class facility. The Olympic Hockey League ice rink has seating for 800 spectators; and the National Hockey League ice rink has 1,200 spectator seats. The collegiate ice sheet has participant seating only. When building the one-year-old facility, the management initially solicited HVAC design/build system plans based on the usual Package Roof Top (RTU) heat/cool units or split system parameters. Such a plan could have been a disaster because high energy costs have contributed directly to the closing of 20 rinks in the Chicago area. This article describes a HVAC system that would take advantage of every Energy Conservation Opportunities (ECO) possible to ensure the economic well being of this property. This included a plan that uses the refrigeration for both cooling and heating, which eliminated the need for commercial packaged units.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. Emergent Properties Delineate Marine Ecosystem Perturbation and Recovery.

    PubMed

    Link, Jason S; Pranovi, Fabio; Libralato, Simone; Coll, Marta; Christensen, Villy; Solidoro, Cosimo; Fulton, Elizabeth A

    2015-11-01

    Whether there are common and emergent patterns from marine ecosystems remains an important question because marine ecosystems provide billions of dollars of ecosystem services to the global community, but face many perturbations with significant consequences. Here, we develop cumulative trophic patterns for marine ecosystems, featuring sigmoidal cumulative biomass (cumB)-trophic level (TL) and 'hockey-stick' production (cumP)-cumB curves. The patterns have a trophodynamic theoretical basis and capitalize on emergent, fundamental, and invariant features of marine ecosystems. These patterns have strong global support, being observed in over 120 marine ecosystems. Parameters from these curves elucidate the direction and magnitude of marine ecosystem perturbation or recovery; if biomass and productivity can be monitored effectively over time, such relations may prove to be broadly useful. Curve parameters are proposed as possible ecosystem thresholds, perhaps to better manage the marine ecosystems of the world. PMID:26456382

  16. Using bifactor exploratory structural equation modeling to examine global and specific factors in measures of sports coaches' interpersonal styles

    PubMed Central

    Stenling, Andreas; Ivarsson, Andreas; Hassmén, Peter; Lindwall, Magnus

    2015-01-01

    In the present work we investigated distinct sources of construct-relevant psychometric multidimensionality in two sport-specific measures of coaches' need-supportive (ISS-C) and controlling interpersonal (CCBS) styles. A recently proposed bifactor exploratory structural equation modeling (ESEM) framework was employed to achieve this aim. In Study 1, using a sample of floorball players, the results indicated that the ISS-C can be considered as a unidimensional measure, with one global factor explaining most of the variance in the items. In Study 2, using a sample of male ice hockey players, the results indicated that the items in the CCBS are represented by both a general factor and specific factors, but the subscales differ with regard to the amount of variance in the items accounted for by the general and specific factors. These results add further insight into the psychometric properties of these two measures and the dimensionality of these two constructs. PMID:26388808

  17. Using bifactor exploratory structural equation modeling to examine global and specific factors in measures of sports coaches' interpersonal styles.

    PubMed

    Stenling, Andreas; Ivarsson, Andreas; Hassmén, Peter; Lindwall, Magnus

    2015-01-01

    In the present work we investigated distinct sources of construct-relevant psychometric multidimensionality in two sport-specific measures of coaches' need-supportive (ISS-C) and controlling interpersonal (CCBS) styles. A recently proposed bifactor exploratory structural equation modeling (ESEM) framework was employed to achieve this aim. In Study 1, using a sample of floorball players, the results indicated that the ISS-C can be considered as a unidimensional measure, with one global factor explaining most of the variance in the items. In Study 2, using a sample of male ice hockey players, the results indicated that the items in the CCBS are represented by both a general factor and specific factors, but the subscales differ with regard to the amount of variance in the items accounted for by the general and specific factors. These results add further insight into the psychometric properties of these two measures and the dimensionality of these two constructs. PMID:26388808

  18. 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

  19. 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

  20. Sports and health: equivalence or contrariety.

    PubMed

    Radić, Borislav; Radić, Petra; Duraković, Din

    2014-12-01

    Playing sports is a widely known method of health promotion. Balanced exercise and diet are keys to healthy life. However, sports activities can cause different injuries, from joint to head injuries. Although head injuries cause a variety of acute and chronic disorders, they are often undertreated. There are 1.6 million injured people examined at emergency departments throughout Europe every year. In sports like boxing, football, soccer, hockey, handball, basketball and bicycling, head injuries occur at a frequency of 4% to 22%. Particularly significant are chronic difficulties that occur after recurrent head injuries, i.e. cognitive deficits and changes in electroencephalogram. Qualifications of professional personnel are insufficient for professional evaluation and treatment of head injuries. The best way for sports to become an important link in health and disease prevention is to go back to sports basics while using acquired scientific knowledge. PMID:25868311

  1. Staying in the game: the 10-step approach to sustaining geriatrics education in hospitalists and subspecialty providers.

    PubMed

    Gillespie, Suzanne M; Brandt, Lynsey E; Chang, Anna; Chao, Serena H; Corcoran, Amy M; Miller, Rachel; Harper, G Michael; Levine, Sharon A; Medina-Walpole, Annette

    2014-08-01

    Geriatrics as a field has been fortunate to have the support of several philanthropic organizations to advance geriatrics education and training in the past two decades. Awardees of such grants were presented with unparalleled opportunities to develop new and innovative educational initiatives affecting learners at multiple levels and in multiple disciplines and specialties. The lessons learned from the Donald W. Reynolds Foundation initiatives about effect and sustainability are invaluable to the ongoing strategic development of geriatrics nationally. This article highlights successful educational initiatives developed at four institutions with past and current Donald W. Reynolds Foundation funding. Following an ice hockey playbook, this article identifies 10 strategies and initiatives to "stay in the geriatrics game" by training hospitalists and subspecialty providers. The authors' collective experience suggests that geriatrics educational initiatives can not only influence provider education, but also improve the care of older adults in multiple settings. PMID:25040491

  2. 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

  3. Decreased motor activity of hyperactive children on dextroamphetamine during active gym program.

    PubMed

    Rapoport, J L; Tepsic, P N; Grice, J; Johnson, C; Langer, D

    1980-07-01

    The motor activity of 10 hyperactive boys was measured during eight 1-hour active gym classes. Children received either dextroaomphetamine (0.5 mg/kg) or placebo elixir before each class, in a double-blind design. The program for each of the classes was participation in the active sports: hockey, basketball, and/or roller skating; the "task" throughout each hour was to play vigorously and continuously. The boys' mean hourly activity following amphetamine was slightly but significantly less than that following placebo. This finding is contradictory to the hypothesis that improved attention to an active task on stimulant would result in increased motor activity, and suggests the possibility of an independent direct effect of amphetamine on the motor system. PMID:6932064

  4. Ankle sprains: surgical treatment for recurrent sprains. Report of 10 patients treated with the Chrisman-Snook modification of the Elmslie procedure.

    PubMed

    Savastano, A A; Lowe, E B

    1980-01-01

    A group of 10 patients (3 women and 7 men; 17 to 57 years old, average 23.9; mean, 21 years) was evaluated preoperatively and postoperatively following surgical repair with a modification of the Elmslie procedure (i.e., by using one-half of the tendinous portion of the peroneus brevis ligament to reconstruct the anterior and middle fasciculi of the lateral ligament). The patients were athletes who participated in bicycling, boxing, tennis, hockey, basketball, football, soccer, or a combination of sports. Each patient gave a history of spraining the ankle numerous times. Stress films were obtained preoperatively and postoperatively. The talar tilt was generally reduced in postoperative films (average preoperatively, 12.5 degrees; average postoperatively, 5.6 degrees). We conclude that the Elmslie procedure, as modified by Chrisman and Snook, is simpler to perform than the Watson-Jones procedure and has provided the majority of our patients with satisfactory results. PMID:6769348

  5. The etiology of primary femoroacetabular impingement: genetics or acquired deformity?

    PubMed Central

    Packer, Jonathan D.; Safran, Marc R.

    2015-01-01

    The etiology of primary femoroacetabular impingement (FAI) remains controversial. Both genetic and acquired causes have been postulated and studied. While recent studies suggest that genetic factors may have a role in the development of FAI, there is no conclusive evidence that FAI is transmitted genetically. Currently, the most popular theory for the development of cam-type deformities is that a repetitive injury to the proximal femoral physis occurs during a critical period of development. There is a correlation between a high volume of impact activities during adolescence and the development of cam-type deformities. Multiple studies have found a high prevalence of FAI in elite football, ice hockey, basketball and soccer players. In this article, we review the current literature relating to the etiology of primary FAI. PMID:27011846

  6. Accuracy of professional sports drafts in predicting career potential.

    PubMed

    Koz, D; Fraser-Thomas, J; Baker, J

    2012-08-01

    The forecasting of talented players is a crucial aspect of building a successful sports franchise and professional sports invest significant resources in making player choices in sport drafts. The current study examined the relationship between career performance (i.e. games played) and draft round for the National Football League, National Hockey League, National Basketball League, and Major League Baseball for players drafted from 1980 to 1989 (n = 4874) against the assumption of a linear relationship between performance and draft round (i.e. that players with the most potential will be selected before players of lower potential). A two-step analysis revealed significant differences in games played across draft rounds (step 1) and a significant negative relationship between draft round and games played (step 2); however, the amount of variance accounted for was relatively low (less than 17%). Results highlight the challenges of accurately evaluating amateur talent. PMID:22092367

  7. Understanding the petrochemical cycle: Part 2

    SciTech Connect

    Sedriks, W. )

    1994-04-01

    The manager of a petrochemical enterprise, to survive the competitive 1990s, must have a good understanding of the industry's cyclicality, and a good grasp of coping alternatives. To select the best strategies and tactics calls for a familiarity with such concepts as the hockey-stick profile for profitability and the experience curve for cost reductions at both ends of the supply curve. The manager must carefully weigh advantages of build-and-scrap policies and differentiation vs. diversification and recognize the pitfalls associated with the prisoner's dilemma. With these elements well understood, the manager is in an improved position to cope with the industry's boom-and-bust characteristics. The paper discusses practicalities, the prisoner's dilemma in game theory, individual company actions, leveraging cyclicability, differentiation and diversification/integration, improvement of competitiveness, and structure as part of the problem.

  8. Does high level youth sports participation increase the risk of femoroacetabular impingement? A review of the current literature.

    PubMed

    de Silva, Viran; Swain, Michael; Broderick, Carolyn; McKay, Damien

    2016-01-01

    Sports participation can be an integral part of adolescent development with numerous positive short and long-term effects. Despite these potential benefits very high levels of physical activity, during skeletal maturation, have been proposed as a possible cause of cam-type femoroacetabular impingement (FAI). The influence of physical activity on the developing physis has been previously described both in animal studies and epidemiological studies of adolescent athletes. It is therefore important to determine whether the development of FAI is secondary to excessive physical activity or a combination of a vulnerable physis and a set level of physical activity. A review of the current literature suggests that adolescent males participating in ice-hockey, basketball and soccer, training at least three times a week, are at greater risk than their non-athletic counterparts of developing the femoral head-neck deformity associated with femoroacetabular impingement. PMID:26968690

  9. Determination of discharge parameters via OES at the Linac4 H(-) ion source.

    PubMed

    Briefi, S; Fink, D; Mattei, S; Lettry, J; Fantz, U

    2016-02-01

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (Te ? 1.2 eV, ne ? 1 10(19) m(-3), and nH/nH2 ? 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal "hockey-stick" rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients. PMID:26931986

  10. Determination of discharge parameters via OES at the Linac4 H- ion source

    NASA Astrophysics Data System (ADS)

    Briefi, S.; Fink, D.; Mattei, S.; Lettry, J.; Fantz, U.

    2016-02-01

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (Te ? 1.2 eV, ne ? 1 1019 m-3, and nH/nH2 ? 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal "hockey-stick" rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients.

  11. Psoas Major: a case report and review of its anatomy, biomechanics, and clinical implications.

    PubMed

    Sajko, Sandy; Stuber, Kent

    2009-12-01

    A 25-year-old male professional hockey player with right sided hip pain was diagnosed with myofascopathy of the right psoas major and rectus femoris. The patient maintained a conservative treatment regimen and was prescribed a four week active strengthening program. The program progressed from resisted concentric exercise to eccentric abduction/adduction exercises along with balance training, core stabilizing and endurance exercises in the first two weeks. In the final two weeks the program progressed to include sport specific exercises. At three weeks the patient was able to participate in non-contact practice and was clear for full contact at five weeks. The anatomy, biomechanics, and function of the psoas major muscle are discussed as is its influence on lumbar spine stability. Evidence-based evaluation and management strategies for psoas dysfunction are presented. PMID:20037696

  12. Sports-related mild traumatic brain injury in female youths

    PubMed Central

    Keightley, Michelle L; Yule, Ashley; Garland, Kimberley; Reed, Nicholas; McAuliffe, Jim; Garton, Janice; Green, Stephanie; Taha, Tim

    2010-01-01

    Sports-related concussion or mild-traumatic brain injury (mTBI) is common in children who participate in organised sports. We describe two case studies involving 14-year-old girls who each sustained a mTBI during ice hockey competition. Neurocognitive functioning post-injury is compared to baseline pre-injury assessment on the same measures. Results from Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Conners' Continuous Performance Test II (CPT-II) and the Attention Network Test (ANT) revealed decreased performance in attention, memory functioning and reaction time. Furthermore, some measures had not returned to baseline at midseason testing sessions approximately 30–40 days post-injury. The results are discussed with respect to the difference in recovery profiles and the need for thorough and ongoing evaluation following mTBI in the paediatric population, and for girls in particular. PMID:22791784

  13. The National Football Head and Neck Injury Registry. 14-year report on cervical quadriplegia, 1971 through 1984.

    PubMed

    Torg, J S; Vegso, J J; Sennett, B; Das, M

    1985-12-27

    Data on cervical spine injuries resulting from participation in football have been compiled by a national registry. Analysis of epidemiologic data and cinematographic documentation clearly demonstrated that the majority of cervical fractures and dislocations were due to axial loading. On the basis of this observation, rule changes banning both deliberate "spearing" and the use of the top of the helmet as the initial point of contact in making a tackle were implemented at the high school and college level. Subsequently, a marked decrease in cervical spine injury rates has occurred. The occurrence of permanent cervical quadriplegia decreased from 34 in 1976 to five in the 1984 season. It is suggested that axial loading of the cervical spine is also responsible for the catastrophic injuries in diving, rugby, ice hockey, and gymnastics. Implementation of appropriate changes in playing techniques and/or equipment modifications could possibly reduce the incidence of cervical spine injuries in these activities. PMID:4068184

  14. Jejunal tackle: a case report of complete jejunal transection in rugby union.

    PubMed

    Perry, William; Fischer, Jesse; Wakeman, Christopher

    2014-09-01

    Jejunal perforation as a result of blunt abdominal trauma during sport is particularly rare. We are aware of 6 reported cases of jejunal perforation in sport: 1 in hockey, 2 in football (soccer), and 3 in American football. This report presents the case of a 25-year-old professional rugby union player, who presented to an "After Hours" general practice clinic with increasing central abdominal and epigastric pain after a heavy tackle during an international match in New Zealand. Despite suffering complete jejunal transection, the patient continued to play on, only presenting to an After Hours general practice clinic 3 hours after the injury. The case demonstrates the remarkable physiological resilience of professional rugby players and acts as a reminder to maintain a high degree of suspicion for small bowel injury despite normal vital signs in healthy young patients with abdominal pain secondary to blunt trauma. PMID:24284950

  15. Systematic discrepancies in Monte Carlo predictions of k-ratios emitted from thin films on substrates

    NASA Astrophysics Data System (ADS)

    Statham, P.; Llovet, X.; Duncumb, P.

    2012-03-01

    We have assessed the reliability of different Monte Carlo simulation programmes using the two available Bastin-Heijligers databases of thin-film measurements by EPMA. The MC simulation programmes tested include Curgenven-Duncumb MSMC, NISTMonte, Casino and PENELOPE. Plots of the ratio of calculated to measured k-ratios ("kcalc/kmeas") against various parameters reveal error trends that are not apparent in simple error histograms. The results indicate that the MC programmes perform quite differently on the same dataset. However, they appear to show a similar pronounced trend with a "hockey stick" shape in the "kcalc/kmeas versus kmeas" plots. The most sophisticated programme PENELOPE gives the closest correspondence with experiment but still shows a tendency to underestimate experimental k-ratios by 10 % for films that are thin compared to the electron range. We have investigated potential causes for this systematic behaviour and extended the study to data not collected by Bastin and Heijligers.

  16. Coefficient of restitution of sports balls: A normal drop test

    NASA Astrophysics Data System (ADS)

    Haron, Adli; Ismail, K. A.

    2012-09-01

    Dynamic behaviour of bodies during impact is investigated through impact experiment, the simplest being a normal drop test. Normally, a drop test impact experiment involves measurement of kinematic data; this includes measurement of incident and rebound velocity in order to calculate a coefficient of restitution (COR). A high speed video camera is employed for measuring the kinematic data where speed is calculated from displacement of the bodies. Alternatively, sensors can be employed to measure speeds, especially for a normal impact where there is no spin of the bodies. This paper compares experimental coefficients of restitution (COR) for various sports balls, namely golf, table tennis, hockey and cricket. The energy loss in term of measured COR and effects of target plate are discussed in relation to the material and construction of these sports balls.

  17. Management of Syndesmotic Ankle Injuries in Children and Adolescents.

    PubMed

    Shore, Benjamin J; Kramer, Dennis E

    2016-06-01

    Pediatric ankle injuries are common, especially in athletes; however, the incidence of syndesmosis injuries in children has been scarcely reported. Injuries to the ankle syndesmosis, termed "high ankle sprains," can affect high-level and recreational athletes and have been related to delayed return to play, persistent pain, and adult injuries have been associated with long-term disability. Syndesmotic injuries do occur in children, especially those who participate in sports that involve cutting and pivoting (football, soccer) or sports with rigid immobilization of the ankle (skiing, hockey). Unstable pediatric syndesmosis injuries requiring surgical fixation are often associated with concomitant fibular fracture in skeletally mature children. Physician vigilance and careful clinical examination coupled with appropriate radiographs can determine the extent of the injury in the majority of circumstances. PMID:27100034

  18. Overview of the Anik C satellites and services

    NASA Astrophysics Data System (ADS)

    Smart, F. H.

    An overview of the important technical characteristics of the Anik C series of Canadian communications satellites is presented. The system was launched as part of the Telesat Communications payload of the Space Shuttle in 1982. Among the services the system will in the near future provide are: a 27 MHz channel bandwidth television service for pay-TV distribution in Canada; two TV channels for hockey broadcasts and a transportable TV system; a heavy-voice route telephone service for five major Canadian cities; and a telephone system for business voice and data communications. Services anticipated for Anik-C satellites later in the decade include a Single Channel Per Carrier (SCPC) voice and data communications system for British Columbia and the Maritime Provinces, and a direct-to-home broadcast service to be sold to television markets in the United States.

  19. Menarcheal age among Indian sportswomen.

    PubMed Central

    Sharma, S S; Shukla, N B

    1992-01-01

    The subjects of the study were 85 Indian sportswomen from Delhi and the states of Uttar Pradesh, Punjab and Gujarat, and included outstanding players of cricket, hockey, kho-kho and table-tennis, who were winners of university, state or national championships. A sample of 77 subjects selected at random was used as the control. The recall procedures suggested by Damon and Bajema (1974) were used. The combined mean age at menarche for sportswomen is 13.56 years and for the control sample is 12.7 years. Menarche was significantly delayed in those sportswomen who embarked on physical training activities before the onset of menstruation. There are also variations in the mean menarcheal age between participants in different sports specialities. PMID:1623359

  20. The Physics of Sports: A Physicist's View

    NASA Astrophysics Data System (ADS)

    Faller, James

    2006-10-01

    In this talk, I will present a physicist's way of looking at various aspects of sports. In particular, I will focus the discussion on how one might improve or enhance performance by thinking as a physicist about the processes involved. Examples that will be discussed will range from why hockey sticks are (today) curved to why good (basketball) dribbling should be ``heard.'' I will present several examples of the benefits of effecting efficiency in motion. This talk will draw on portions of presentations that I have given in the Boulder-Denver area during the past 30 years on the physics of sports. In all these presentations, my purpose was to teach and develop student interest in physics while talking about -- and showing the relevance of physics to -- sports.

  1. [Sports-related concussions in youths].

    PubMed

    Minodier, P; Guillaume, J-M; Coudreuse, J-M; Viton, J-M; Jouve, J-L; Merrot, T

    2015-04-01

    Mild head trauma can be associated with concussion, defined as transient brain function impairment without radiological findings. Sports-related concussion is also reported in pediatrics (rugby, ice hockey, football, boxing, etc.). Misdiagnosis can lead to persistent neurocognitive signs with athletic and academic problems. Consensual tools are available, but they are not well-known by first-line doctors, coaches, and patients or parents. Concussed players should not be allowed to return to the field on the same day. Return to play should be gradual over 3weeks or more. School activities may need to be modified to favor cognitive rest. Prevention is based on risk information and knowledge transfer, rule changes, and protective helmets, whose effectiveness is not always proven. PMID:25497367

  2. Stress reaction of the pars interarticularis leading to spondylolysis. A cause of adolescent low back pain.

    PubMed

    Weir, M R; Smith, D S

    1989-11-01

    We report an adolescent with progression from a stress reaction of the pars interarticularis without radiographic findings, to radiographic fracture and spondylolysis, illustrating the evolution of spondylolysis in an athletically active early adolescent. Gymnastics, diving, pole vaulting, or collision/contact sports such as football, soccer, hockey, and la crosse are common sports with a disproportional frequency of spondylolysis. Rotational forces around the long axis of the spine with load bearing hyperextension are important in etiology. Low back pain in the active adolescent or preadolescent, even with normal oblique lumbar radiographs, may have a treatable origin--stress reaction or fracture of a lumbar pars interarticularis. Screening evaluation is the standing one-leg extension maneuver. Liberal use of nuclear studies for minimal back symptoms in athletic adolescents may help exclude this relatively common, potentially treatable condition, spondylolysis of the pars interarticularis. PMID:2532632

  3. Predictors of poor sportspersonship in youth sports: personal attitudes and social influences.

    PubMed

    Shields, David Light; LaVoi, Nicole M; Bredemeier, Brenda Light; Power, F Clark

    2007-12-01

    The present study examined personal and social correlates of poor sportspersonship among youth sport participants. Male and female athletes (n = 676) in the fifth through eighth grades from three geographic regions of the U.S. participated in the study. Young athletes involved in basketball, soccer, football, hockey, baseball/ softball, or lacrosse completed a questionnaire that tapped poor sportspersonship behaviors and attitudes, team sportspersonship norms, perceptions of the poor sportspersonship behaviors of coaches and spectators, and the sportspersonship norms of coaches and parents. Preliminary analyses revealed significant gender, grade, sport area, and location differences in self-reported unsportspersonlike behavior. The main analysis revealed that self-reported poor sport behaviors were best predicted by perceived coach and spectator behaviors, followed by team norms, sportspersonship attitudes, and the perceived norms of parents and coaches. Results are discussed in relation to the concept of moral atmosphere. PMID:18089902

  4. Ultrasonography in the diagnosis of nasal bone fractures: a comparison with conventional radiography and computed tomography.

    PubMed

    Lee, In Sook; Lee, Jung-Hoon; Woo, Chang-Ki; Kim, Hak Jin; Sol, Yu Li; Song, Jong Woon; Cho, Kyu-Sup

    2016-02-01

    The purpose of this study was to evaluate and compare the diagnostic efficacy of ultrasonography (US) with radiography and multi-detector computed tomography (CT) for the detection of nasal bone fractures. Forty-one patients with a nasal bone fracture who underwent prospective US examinations were included. Plain radiographs and CT images were obtained on the day of trauma. For US examinations, radiologist used a linear array transducer (L17-5 MHz) in 24 patients and hockey-stick probe (L15-7 MHz) in 17. The bony component of the nose was divided into three parts (right and left lateral nasal walls, and midline of nasal bone). Fracture detection by three modalities was subjected to analysis. Furthermore, findings made by each modality were compared with intraoperative findings. Nasal bone fractures were located in the right lateral wall (n = 28), midline of nasal bone (n = 31), or left lateral wall (n = 31). For right and left lateral nasal walls, CT had greater sensitivity and specificity than US or radiography, and better agreed with intraoperative findings. However, for midline fractures of nasal bone, US had higher specificity, positive predictive value, and negative predictive value than CT. Although two US evaluations showed good agreements at all three sites, US findings obtained by the hockey-stick probe showed closer agreement with intraoperative findings for both lateral nasal wall and midline of nasal bone. Although CT showed higher sensitivity and specificity than US or radiography, US found to be helpful for evaluating the midline of nasal bone. Furthermore, for US examinations of the nasal bone, a smaller probe and higher frequency may be required. PMID:25749616

  5. Realistic uncertainties on Hapke model parameters from photometric measurement

    NASA Astrophysics Data System (ADS)

    Schmidt, Frédéric; Fernando, Jennifer

    2015-11-01

    The single particle phase function describes the manner in which an average element of a granular material diffuses the light in the angular space usually with two parameters: the asymmetry parameter b describing the width of the scattering lobe and the backscattering fraction c describing the main direction of the scattering lobe. Hapke proposed a convenient and widely used analytical model to describe the spectro-photometry of granular materials. Using a compilation of the published data, Hapke (Hapke, B. [2012]. Icarus 221, 1079-1083) recently studied the relationship of b and c for natural examples and proposed the hockey stick relation (excluding b > 0.5 and c > 0.5). For the moment, there is no theoretical explanation for this relationship. One goal of this article is to study a possible bias due to the retrieval method. We expand here an innovative Bayesian inversion method in order to study into detail the uncertainties of retrieved parameters. On Emission Phase Function (EPF) data, we demonstrate that the uncertainties of the retrieved parameters follow the same hockey stick relation, suggesting that this relation is due to the fact that b and c are coupled parameters in the Hapke model instead of a natural phenomena. Nevertheless, the data used in the Hapke (Hapke, B. [2012]. Icarus 221, 1079-1083) compilation generally are full Bidirectional Reflectance Diffusion Function (BRDF) that are shown not to be subject to this artifact. Moreover, the Bayesian method is a good tool to test if the sampling geometry is sufficient to constrain the parameters (single scattering albedo, surface roughness, b, c , opposition effect). We performed sensitivity tests by mimicking various surface scattering properties and various single image-like/disk resolved image, EPF-like and BRDF-like geometric sampling conditions. The second goal of this article is to estimate the favorable geometric conditions for an accurate estimation of photometric parameters in order to provide new constraints for future observation campaigns and instrumentations.

  6. The influence of the sensor type on the measured impact absorption of mouthguard material.

    PubMed

    Takeda, Tomotaka; Ishigami, Keiichi; Jun, Handa; Nakajima, Kazunori; Shimada, Atsushi; Ogawa, Toru

    2004-02-01

    Mouthguards have been tested for impact energy absorption using drop-ball and/or pendulum devices. While all reports show efficiency of the mouthguard, the impact absorption abilities reported differ considerably. This difference has been attributed to differences of mouthguard material, design, and the impact force used. However, it is also possibly because of the difference in the sensors used in the experiments. The purpose of this study was to test three types of sensors and to assess which type was most appropriate for measurement of the impact absorption ability of mouthguards. A pendulum-type testing equipment and steel ball, wooden bat, baseball, field-hockey ball were used as the impact object. For all sensors or impact objects, the mouthguard decreased the impact forces. However, the absorption ability of the mouthguard varied according to the sensor or impact object. The absorbency values became smaller with the strain gauge, the accelerometer, and the load cell, respectively. With the steel ball as the impact object, 80.3% of impact absorption was measured with the strain gauge and the accelerometer but, only 62.1% with the load cell sensor. With the wooden bat, impact absorption was 76.3% with the strain gauge and 38.8% for the load cell. For the baseball ball, the absorption measurement decreased from 46.3% with the strain gauge to 4.36 with the load cell and for the field-hockey ball, the decrease in measurement values were similar (23.6% with the strain gauge and 2.43% with the load cell). It is clear that the sensor plays an important role in the measurement values reported for absorbency of mouthguard materials and a standard sensor should be used for all experiments. PMID:14998412

  7. Fuzzy sliding-mode formation control for multirobot systems: design and implementation.

    PubMed

    Chang, Yeong-Hwa; Chang, Chia-Wen; Chen, Chun-Lin; Tao, Chin-Wang

    2012-04-01

    This paper mainly addresses the decentralized formation problems for multiple robots, where a fuzzy sliding-mode formation controller (FSMFC) is proposed. The directed networks of dynamic agents with external disturbances and system uncertainties are discussed in consensus problems. To perform a formation control and to guarantee system robustness, a novel formation algorithm combining the concepts of graph theory and fuzzy sliding-model control is presented. According to the communication topology, formation stability conditions can be determined so that an FSMFC can be derived. By Lyapunov stability theorem, not only the system stability can be guaranteed, but the desired formation pattern of a multirobot system can be also achieved. Simulation results are provided to demonstrate the effectiveness of the provided control scheme. Finally, an experimental setup for the e-puck multirobot system is built. Compared to first-order formation algorithm and fuzzy neural network formation algorithm, it shows that real-time experimental results empirically support the promising performance of desire. PMID:22010151

  8. Use of piezoelectric dampers for improving the feel of golf clubs

    NASA Astrophysics Data System (ADS)

    Bianchini, Emanuele; Spangler, Ronald L., Jr.; Pandell, Tracy

    1999-06-01

    Several sports are based upon a tool (club, bat, stick) striking an object (ball, puck) across a field of play. Anytime two structures collide, vibration is created by the impact of the two. The impact of the objects excites the structural modes of the tool, creating a vibration that can be felt by the player, especially if the hit is not at a `sweet spot'. Vibration adversely affects both feel and performance. This paper explains how piezoelectric dampers were developed to reduce vibration and improve the feel of ball-impact sporting goods such as golf clubs. The paper describes how the dynamic characteristics of a golf club were calculated, at first in the free-free condition, and then during its operation conditions (the swing of the club, and the impact with the ball). The dynamic characteristics were used to develop a damper that addressed a specific, or multiple, modes of interest. The damper development and testing are detailed in this paper. Both objective laboratory tests and subjective player tests were performed to evaluate the effectiveness of the piezoelectric dampers. The results of the tests, along with published medical data on the sensitivity of the human body, were used to draw a correlation between human feel and vibration reduction.

  9. Adhesive RFID Sensor Patch for Monitoring of Sweat Electrolytes.

    PubMed

    Rose, Daniel P; Ratterman, Michael E; Griffin, Daniel K; Hou, Linlin; Kelley-Loughnane, Nancy; Naik, Rajesh R; Hagen, Joshua A; Papautsky, Ian; Heikenfeld, Jason C

    2015-06-01

    Wearable digital health devices are dominantly found in rigid form factors such as bracelets and pucks. An adhesive radio-frequency identification (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 solutes in sweat, and surface temperature, as read by an Android smartphone app with 96% accuracy at 50 mM Na(+) (in vitro tests). All circuitry is solder-reflow integrated on a standard Cu/polyimide flexible-electronic layer including an antenna, but while also allowing electroplating for simple integration of exotic metals for sensing electrodes. Optional paper microfluidics wick sweat from a sweat porous adhesive allowing flow to the sensor, or the sensor can be directly contacted to the skin. The wearability of the patch has been demonstrated for up to seven days, and includes a protective textile which provides a feel and appearance similar to a standard Band-Aid. Applications include hydration monitoring, but the basic capability is extendable to other mM ionic solutes in sweat (Cl(-), K(+), Mg(2+), NH4(+), and Zn(2+)). The design and fabrication of the patch are provided in full detail, as the basic components could be useful in the design of other wearable sensors. PMID:25398174

  10. Mimas: Tectonic structure and geologic history

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1991-01-01

    Mimas, the innermost of the major saturnian satellites, occupies an important place in comparative studies of icy satellites. It is the smallest icy satellite known to have a mostly spherical shape. Smaller icy objects like Hyperion and Puck are generally irregular in shape, while larger ones like Miranda and Enceladus are spherical. Thus Mimas is near the diameter where the combination of increasing surface gravity and internal heating begin to have a significant effect on global structure. The nature and extent of endogenic surface features provide important constraints on the interior structure and history of this transitional body. The major landforms on Mimas are impact craters. Mimas has one of the most heavily cratered surfaces in the solar system. The most prominent single feature on Mimas is Herschel, an unrelaxed complex crater 130 km in diameter. The only other recognized landforms on Mimas are tectonic grooves and lineaments. Groove locations were mapped by Schenk, but without analysis of groove structures or superposition relationships. Mimas' tectonic structures are remapped here in more detail than previously has been done, as part of a general study of tectonic features on icy satellites.

  11. Thermoelectric Power Generation from Lanthanum Strontium Titanium Oxide at Room Temperature through the Addition of Graphene.

    PubMed

    Lin, Yue; Norman, Colin; Srivastava, Deepanshu; Azough, Feridoon; Wang, Li; Robbins, Mark; Simpson, Kevin; Freer, Robert; Kinloch, Ian A

    2015-07-29

    The applications of strontium titanium oxide based thermoelectric materials are currently limited by their high operating temperatures of >700 °C. Herein, we show that the thermal operating window of lanthanum strontium titanium oxide (LSTO) can be reduced to room temperature by the addition of a small amount of graphene. This increase in operating performance will enable future applications such as generators in vehicles and other sectors. The LSTO composites incorporated one percent or less of graphene and were sintered under an argon/hydrogen atmosphere. The resultant materials were reduced and possessed a multiphase structure with nanosized grains. The thermal conductivity of the nanocomposites decreased upon the addition of graphene, whereas the electrical conductivity and power factor both increased significantly. These factors, together with a moderate Seebeck coefficient, meant that a high power factor of ∼2500 μWm(-1)K(-2) was reached at room temperature at a loading of 0.6 wt % graphene. The highest thermoelectric figure of merit (ZT) was achieved when 0.6 wt % graphene was added (ZT = 0.42 at room temperature and 0.36 at 750 °C), with >280% enhancement compared to that of pure LSTO. A preliminary 7-couple device was produced using bismuth strontium cobalt oxide/graphene-LSTO pucks. This device had a Seebeck coefficient of ∼1500 μV/K and an open voltage of 600 mV at a mean temperature of 219 °C. PMID:26095083

  12. Composite Structural Analysis of Flat-Back Shaped Blade for Multi-MW Class Wind Turbine

    NASA Astrophysics Data System (ADS)

    Kim, Soo-Hyun; Bang, Hyung-Joon; Shin, Hyung-Ki; Jang, Moon-Seok

    2014-06-01

    This paper provides an overview of failure mode estimation based on 3D structural finite element (FE) analysis of the flat-back shaped wind turbine blade. Buckling stability, fiber failure (FF), and inter-fiber failure (IFF) analyses were performed to account for delamination or matrix failure of composite materials and to predict the realistic behavior of the entire blade region. Puck's fracture criteria were used for IFF evaluation. Blade design loads applicable to multi-megawatt (MW) wind turbine systems were calculated according to the Germanischer Lloyd (GL) guideline and the International Electrotechnical Commission (IEC) 61400-1 standard, under Class IIA wind conditions. After the post-processing of final load results, a number of principal load cases were selected and converted into applied forces at the each section along the blade's radius of the FE model. Nonlinear static analyses were performed for laminate failure, FF, and IFF check. For buckling stability, linear eigenvalue analysis was performed. As a result, we were able to estimate the failure mode and locate the major weak point.

  13. Formalization, implementation, and modeling of institutional controllers for distributed robotic systems.

    PubMed

    Pereira, José N; Silva, Porfírio; Lima, Pedro U; Martinoli, Alcherio

    2014-01-01

    The work described is part of a long term program of introducing institutional robotics, a novel framework for the coordination of robot teams that stems from institutional economics concepts. Under the framework, institutions are cumulative sets of persistent artificial modifications made to the environment or to the internal mechanisms of a subset of agents, thought to be functional for the collective order. In this article we introduce a formal model of institutional controllers based on Petri nets. We define executable Petri nets-an extension of Petri nets that takes into account robot actions and sensing-to design, program, and execute institutional controllers. We use a generalized stochastic Petri net view of the robot team controlled by the institutional controllers to model and analyze the stochastic performance of the resulting distributed robotic system. The ability of our formalism to replicate results obtained using other approaches is assessed through realistic simulations of up to 40 e-puck robots. In particular, we model a robot swarm and its institutional controller with the goal of maintaining wireless connectivity, and successfully compare our model predictions and simulation results with previously reported results, obtained by using finite state automaton models and controllers. PMID:23373975

  14. CRADA final report for CRADA number C/Y-1203-0211, gelcasting of soft ferrite parts

    SciTech Connect

    Omatete, O.O.; Van Dillen, G.L., Jr.

    1996-03-01

    Soft ferrite parts utilized in areas such as high-energy physics have been successfully gelcast from powders supplied by the industrial partner. To achieve this, several modifications were necessary. First, the as-received ferrite powder was heated to 300, 500 or 800{degrees}C. X-ray analysis showed no changes in the crystal structure of the heat-treated powder even at 800{degrees}C, and particle size distribution and surface area analyses indicated that powders heat treated at 300 and 500{degrees} had mean size and surface area similar to those of the as-received powder. Second, to prevent the parts from shattering during the combined binder burn-off and sintering cycle, the solids loading of the gelcasting slurry was adjusted from 42 vol % to at least 50 vol % and the sintering schedule was modified slightly. These modifications resulted in the production of fired gelcast soft ferrite parts (50 mm {times} 13 mm pucks, {approximately} 125 mm OD {times} 100 mm ID {times} 25 mm rings) which sintered to {approximately}98% of the theoretical density. The partner was satisfied with the parts it received and has discussed pursuing follow-up activities in order to gelcast more complex shapes and large toroids.

  15. Bacterial growth rates are influenced by cellular characteristics of individual species when immersed in electromagnetic fields.

    PubMed

    Tessaro, Lucas W E; Murugan, Nirosha J; Persinger, Michael A

    2015-03-01

    Previous studies have shown that exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) have negative effects on the rate of growth of bacteria. In the present study, two Gram-positive and two Gram-negative species were exposed to six magnetic field conditions in broth cultures. Three variations of the 'Thomas' pulsed frequency-modulated pattern; a strong-static "puck" magnet upwards of 5000G in intensity; a pair of these magnets rotating opposite one another at ∼30rpm; and finally a strong dynamic magnetic field generator termed the 'Resonator' with an average intensity of 250μT were used. Growth rate was discerned by optical density (OD) measurements every hour at 600nm. ELF-EMF conditions significantly affected the rates of growth of the bacterial cultures, while the two static magnetic field conditions were not statistically significant. Most interestingly, the 'Resonator' dynamic magnetic field increased the rates of growth of three species (Staphylococcus epidermidis, Staphylococcus aureus, and Escherichia coli), while slowing the growth of one (Serratia marcescens). We suggest that these effects are due to individual biophysical characteristics of the bacterial species. PMID:25721476

  16. Finite element based damage assessment of composite tidal turbine blades

    NASA Astrophysics Data System (ADS)

    Fagan, Edward M.; Leen, Sean B.; Kennedy, Ciaran R.; Goggins, Jamie

    2015-07-01

    With significant interest growing in the ocean renewables sector, horizontal axis tidal current turbines are in a position to dominate the marketplace. The test devices that have been placed in operation so far have suffered from premature failures, caused by difficulties with structural strength prediction. The goal of this work is to develop methods of predicting the damage level in tidal turbines under their maximum operating tidal velocity. The analysis was conducted using the finite element software package Abaqus; shell models of three representative tidal turbine blades are produced. Different construction methods will affect the damage level in the blade and for this study models were developed with varying hydrofoil profiles. In order to determine the risk of failure, a user material subroutine (UMAT) was created. The UMAT uses the failure criteria designed by Alfred Puck to calculate the risk of fibre and inter-fibre failure in the blades. The results show that degradation of the stiffness is predicted for the operating conditions, having an effect on the overall tip deflection. The failure criteria applied via the UMAT form a useful tool for analysis of high risk regions within the blade designs investigated.

  17. Orbital analysis of the inner Uranian satellites from Hubble images

    NASA Astrophysics Data System (ADS)

    French, Robert S.; Showalter, Mark R.; de Pater, Imke; Lissauer, Jack J.

    2015-11-01

    The thirteen inner moons of Uranus form a densely-packed and possibly chaotic system. Numerical simulations show that several groups of moons exhibit complex resonant interactions, and Mab shows as-yet unexplained variations in its orbit. However, the masses of these moons are currently unknown, limiting the insights that can be gained from numerical simulations. Using over 650 long-exposure images taken during 2003-2013 by the Hubble Space Telescope through broadband filters, we have obtained astrometry for eleven of Uranus’s inner moons, comprising the Portia group (Bianca to Perdita) plus Puck and Mab; attempts to measure the positions of Cordelia and Ophelia are on-going. Using these measurements, which are frequently accurate to 0.05 pixels or less, we have derived Keplerian orbital elements including the influence of Uranus’s oblateness. The elements show year-to-year variations that are statistically significant and indicate the role of mutual perturbations among the moons. We are also using this information to place new constraints on the masses of these moons. We will present our most recent findings.

  18. CANVAS: C++ objects for easy graphics on an Evans and Sutherland PS390 terminal

    SciTech Connect

    Michelotti, L.; Kick, R.

    1990-08-27

    The C++ classes described in this note comprise an attempt to provide an object-oriented approach, and if there was ever a graphics terminal naturally suited to object-oriented programming, the PS390 is it. Since a canvas is not a program but a variable to be used in programs, users can write software to suit their particular needs. By simply declaring canvas variables the application program is provided with an object which accepts data and displays it automatically. Any number of canvases can be placed anywhere on the screen, so data can be viewed in a variety of ways simultaneously. Further, the real-time'' transformation capabilities of the PS390 are activated in one step by connecting'' its external devices, the dials and the puck, to the desired canvas. There is no need for the applications programmer to construct his own function networks, choose names for nodes, and do any of the other administrative tasks laid out in the manuals, including connecting the terminal to a host computer and initializing it. These are handled automatically by the canvases themselves, thus removing this clutter from the application program.

  19. Submarine groundwater discharge to the Baltic coastal zone: Impacts on the meiofaunal community

    NASA Astrophysics Data System (ADS)

    Kotwicki, L.; Grzelak, K.; Czub, M.; Dellwig, O.; Gentz, T.; Szymczycha, B.; Böttcher, M. E.

    2014-01-01

    The discharge of groundwater into the sea affects surrounding environments by changing the salinity, temperature and nutrient regimes. This work reports the spatial effects of a submarine groundwater discharge (SGD) on the abundance and structure of the meiofaunal community in the shallow area of Puck Bay (Baltic Sea). Several field expeditions in the years 2009 and 2010 found that low-saline groundwater escapes into the bay from permeable, sandy, near-shore sediments. The SGD literature has grown rapidly during the current decade; however, the effects of this type of disturbance on the shallow sandy bottom fauna have thus far been little studied. We provide evidence that the discharge of groundwater has a clear effect on meiofaunal assemblages in the research area. This effect was reflected in a significant decline of certain meiofaunal taxa, mainly nematodes and harpacticoids, as well as in altered patterns of temporal distribution and small-scale (vertical) zonation of meiofaunal assemblages. Overlooking submarine groundwater discharge processes may lead to serious misinterpretations of ecological data. It is clear that groundwater discharge phenomena should be considered in future scientific studies.

  20. Research of marine sensor web based on SOA and EDA

    NASA Astrophysics Data System (ADS)

    Jiang, Yongguo; Dou, Jinfeng; Guo, Zhongwen; Hu, Keyong

    2015-04-01

    A great deal of ocean sensor observation data exists, for a wide range of marine disciplines, derived from in situ and remote observing platforms, in real-time, near-real-time and delayed mode. Ocean monitoring is routinely completed using sensors and instruments. Standardization is the key requirement for exchanging information about ocean sensors and sensor data and for comparing and combining information from different sensor networks. One or more sensors are often physically integrated into a single ocean `instrument' device, which often brings in many challenges related to diverse sensor data formats, parameters units, different spatiotemporal resolution, application domains, data quality and sensors protocols. To face these challenges requires the standardization efforts aiming at facilitating the so-called Sensor Web, which making it easy to provide public access to sensor data and metadata information. In this paper, a Marine Sensor Web, based on SOA and EDA and integrating the MBARI's PUCK protocol, IEEE 1451 and OGC SWE 2.0, is illustrated with a five-layer architecture. The Web Service layer and Event Process layer are illustrated in detail with an actual example. The demo study has demonstrated that a standard-based system can be built to access sensors and marine instruments distributed globally using common Web browsers for monitoring the environment and oceanic conditions besides marine sensor data on the Web, this framework of Marine Sensor Web can also play an important role in many other domains' information integration.

  1. EPICS controlled sample mounting robots at the GM/CA CAT.

    SciTech Connect

    Makarov, O. A.; Benn, R.; Corcoran, S.; Devarapalli, S.; Fischetti, R.; Hilgart, M.; Smith, W. W.; Stepanov, S.; Xu, S.; Biosciences Division

    2007-11-11

    GM/CA CAT at Sector 23 of the advanced photon source (APS) is an NIH funded facility for crystallographic structure determination of biological macromolecules by X-ray diffraction [R.F. Fischetti, et al., GM/CA canted undulator beamlines for protein crystallography, Acta Crystallogr. A 61 (2005) C139]. The facility consists of three beamlines; two based on canted undulators and one on a bending magnet. The scientific and technical goals of the CAT emphasize streamlined, efficient throughput for a variety of sample types, sizes and qualities, representing the cutting edge of structural biology research. For this purpose all three beamlines are equipped with the ALS-style robots [C.W.Cork, et al. Status of the BCSB automated sample mounting and alignment system for macromolecular crystallography at the Advanced Light Source, SRI-2003, San-Francisco, CA, USA, August 25-29, 2003] for an automated mounting of cryo-protected macromolecular crystals. This report summarizes software and technical solutions implemented with the first of the three operational robots at beamline 23-ID-B. The automounter's Dewar can hold up to 72 or 96 samples residing in six Rigaku ACTOR magazines or ALS-style pucks, respectively. Mounting of a crystal takes approximately 2 s, during which time the temperature of the crystal is maintained near that of liquid nitrogen.

  2. Effects of Vitamin E on the Oxidative Reaction of Free Radicals in Ultra-High Molecular Weight Polyethylene

    NASA Astrophysics Data System (ADS)

    Walters, Benjamin; Jahan, Muhammad

    2008-03-01

    Free radicals in gamma- or x-irradiated ultra-high molecular weight polyethylene (UHMWPE) are investigated as a function of vitamin E (alpha-tocopherol (α-T)). α-T is mixed with UHMWPE (GUR 1020) powder (e-PE) before (premix) or after (post-mix) irradiation. Pre-mix powder is also compression-molded (CM) to solid pucks (1'' thick and 2.5'' dia.) at 200^oC under constant force of 20-40 kN. Free radicals are detected using an X-band electron spin resonance (ESR) spectrometer, and oxidation index (OI) (1720 cm-1) by FTIR technique. As expected, no measurable OI is detected by FTIR and thus e-PE suffers no loss in its mechanical properties. ESR data, however, suggest that α-T quenches polyethylene radicals during and/or immediately after irradiation, but it does not have any effect on the long-term oxidative reaction. The difference between the pre- and post-mix powder is apparent only at the initial stage, and the terminal oxygen-induced radicals (OIR) are produced in all irradiated samples. Both pre- and post-mix powders are found to have equal amount of residual α-T radical (tocopheroxyl).

  3. ICF Gamma-Ray measurements on the NIF

    NASA Astrophysics Data System (ADS)

    Herrmann, Hans; Kim, Y.; Hoffman, N. M.; Batha, S. H.; Stoeffl, W.; Church, J. A.; Sayre, D. B.; Liebman, J. A.; Cerjan, C. J.; Carpenter, A. C.; Grafil, E. M.; Khater, H. Y.; Horsfield, C. J.; Rubery, M.

    2013-10-01

    The primary objective of the NIF Gamma Reaction History (GRH) diagnostic is to provide bang time and burn width information in order to constrain implosion simulation parameters such as shell velocity and confinement time. This is accomplished by measuring DT fusion gamma-rays with energy-thresholded Gas Cherenkov detectors that convert MeV gamma-rays into UV/visible photons for high-bandwidth optical detection. Burn-weighted CH ablator areal density is also inferred based on measurement of the 12C(n,n') gammas emitted at 4.44 MeV from DT neutrons inelastically scattering off carbon nuclei as they pass through the plastic ablator. This requires that the four independent GRH gas cells be set to differing Cherenkov thresholds (e.g., 2.9, 4.5, 8 & 10 MeV) in order to be able to unfold the primary spectral components predicted to be in the gamma ray energy spectrum (i.e., DT γ 27Al & 28Si (n,n') γ from the thermo-mechanical package (TMP); and 12C(n,n' γ from the ablator). The GRH response to 12C(n,n') γ is calibrated in-situ by placing a known areal density of carbon in the form of a puck placed ~6 cm from a DT exploding pusher implosion. Comparisons between inferred gamma fluences and simulations based on the nuclear cross sections databases will be presented. Supported by US DOE NNSA.

  4. Application of Molded Interconnect Device technology to the realization of a self-biased circulator

    NASA Astrophysics Data System (ADS)

    Laur, Vincent; Mattei, Jean-Luc; Vérissimo, Grégory; Queffelec, Patrick; Lebourgeois, Richard; Ganne, Jean-Pierre

    2016-04-01

    This paper describes the first electromagnetic characterization of a self-biased circulator in molded interconnect device (MID) technology. The circulator was designed using a 3D full-wave commercial simulator. It consists of microstrip access lines connected to a Y-junction in Substrate Integrated Waveguide (SIW) technology. Unlike classical technologies, the SIW Y-junction was not fabricated using metallic vias but by a Laser Direct Structuring (LDS) technique. A molded Cyclo-Olefin Polymer (COP) was used as a substrate and 3D metallized. The microwave properties of LDS-compatible COP are not well known so we investigated them through the use of cavity-perturbation and rectangular waveguide characterization methods. The device was then machined to insert a pre-oriented strontium hexaferrite puck doped with cobalt and lanthanum (Sr0,7La0,3Fe11,7Co0,3O19). The characteristics of the MID circulator were assessed between 28 and 32 GHz. Without magnets, insertion losses of 3.32 dB were measured at 30.7 GHz. At the same frequency, an isolation level of 13.89 dB and return losses of 19.89 dB were observed. These measurements demonstrate for the first time the high potential of MID technology for the realization of low-cost non-reciprocal devices.

  5. Implementation and Evaluation of Four Interoperable Open Standards for the Internet of Things

    PubMed Central

    Jazayeri, Mohammad Ali; Liang, Steve H. L.; Huang, Chih-Yuan

    2015-01-01

    Recently, researchers are focusing on a new use of the Internet called the Internet of Things (IoT), in which enabled electronic devices can be remotely accessed over the Internet. As the realization of IoT concept is still in its early stages, manufacturers of Internet-connected devices and IoT web service providers are defining their proprietary protocols based on their targeted applications. Consequently, IoT becomes heterogeneous in terms of hardware capabilities and communication protocols. Addressing these heterogeneities by following open standards is a necessary step to communicate with various IoT devices. In this research, we assess the feasibility of applying existing open standards on resource-constrained IoT devices. The standard protocols developed in this research are OGC PUCK over Bluetooth, TinySOS, SOS over CoAP, and OGC SensorThings API. We believe that by hosting open standard protocols on IoT devices, not only do the devices become self-describable, self-contained, and interoperable, but innovative applications can also be easily developed with standardized interfaces. In addition, we use memory consumption, request message size, response message size, and response latency to benchmark the efficiency of the implemented protocols. In all, this research presents and evaluates standard-based solutions to better understand the feasibility of applying existing standards to the IoT vision. PMID:26402683

  6. Experimental investigation of the failure envelope of unidirectional carbon-epoxy composite under high strain rate transverse and off-axis tensile loading

    NASA Astrophysics Data System (ADS)

    Kuhn, Peter; Ploeckl, Marina; Koerber, Hannes

    2015-09-01

    The mechanical response of the carbon-epoxy material system HexPly IM7-8552 was investigated under transverse tension and combined transverse tension / in-plane shear loading at quasi-static and dynamic strain rates. The dynamic tests of the transverse tension and off-axis tension specimens were carried out on a split-Hopkinson tension bar system, while the quasi-static reference tests were performed on a standard electro-mechanical testing machine. Digital image correlation was used for data reduction at both strain rate regimes. For the high rate tests, the strain rate in loading direction was adjusted to reach approximately the same strain rate value in the fracture plane for each specimen. The measured axial strengths were transformed from the global coordinate system into the combined transverse tension-shear stress space of the material coordinate system and compared with the Puck Mode A criterion for inter-fibre failure. A good correlation between the experimental data and the predicted failure envelopes was found for both investigated strain rate regimes.

  7. AUV Measured Variability in Phytoplankton Fluorescence within the ETM of the Columbia River during Summer 2013

    NASA Astrophysics Data System (ADS)

    McNeil, C. L.; Shcherbina, A.; Litchendorf, T. M.; Sanford, T. B.; Martin, D.; Baptista, A. M.; Lopez, J.; Crump, B. C.; Peterson, T. D.; Prahl, F. G.; Cravo, A.

    2014-12-01

    We present highly resolved observations of fluorescence and optical backscatter taken in the estuarine turbidity maxima (ETM) of the North Channel of the Columbia River estuary (USA) during summer 2013. Measurements were made using two REMUS-100 autonomous underwater vehicles (AUVs) equipped with ECO Puck triplets. Concentrations of three phytoplankton pigments were measured by fluorescence emission at wavelengths of 695 nm for chlorophyll, 570 nm for phycoerythrin, and 680 nm for phycocyanin. We use phycocyanin to indicate the presence of freshwater phytoplankton. Optical backscatter at wavelengths of 700 nm and 880 nm are used to characterize turbidity. During flood tide, high phycocyanin concentrations were associated with a strong ETM event which had relatively low salinity waters of approximately 6 psu. These data indicate that this low salinity ETM event contained large concentrations of freshwater phytoplankton. Since freshwater phytoplankton are known to lyse in saltwater, the brackish ETM event may have formed by the accumulation of lysed freshwater phytoplankton that settled out from the river as it mixed in the lower estuary. As the flood tide proceeded, it brought high concentrations of marine phytoplankton into the north channel at mid-depth as indicated by high chlorophyll levels with significantly lower phycoerythrin concentrations in high salinity waters of approximately 30 psu. The data set highlights the potential for large variability in phytoplankton species composition and concentrations within the ETM depending on mixing rates and phytoplankton bloom dynamics. Visualization of the 4-D data is aided by generating interpolated data movies.

  8. Measurement of areal density in the ablators of inertial-confinement-fusion capsules via detection of ablator (n, n Prime {gamma}) gamma-ray emission

    SciTech Connect

    Hoffman, N. M.; Herrmann, H. W.; Kim, Y. H.; Hsu, H. H.; Young, C. S.; Mack, J. M.; Wilson, D. C.; Langenbrunner, J. R.; Evans, S. C.; Sedillo, T. J.; Horsfield, C. J.; Rubery, M. S.; Miller, E. K.; Grafil, E.; Stoeffl, W.; Church, J. A.; Glebov, V. Yu.; Duffy, T.

    2013-04-15

    We report the first gamma-ray-based measurements of the areal density of ablators in inertial-confinement-fusion capsule implosions. The measurements, made at the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)], used observations of gamma rays arising from inelastic scattering of 14.1-MeV deuterium-tritium (DT) neutrons on {sup 12}C nuclei in the compressed plastic ablators. The emission of {sup 12}C(n,n Prime {gamma}) gamma rays from the capsules is detected using the Gamma Reaction History instrument [H. W. Herrmann et al., J. Phys.: Conf. Ser. 244, 032047 (2010)] operating at OMEGA. From the ratio of a capsule's {sup 12}C(n,n Prime {gamma}) emission to the emission from the same processes in an in situ reference graphite 'puck' of known mass and geometry [N. M. Hoffman et al., in IFSA 2011 proceedings (submitted)], we determine the time-averaged areal density of {sup 12}C in the capsule's compressed ablator. Measured values of total ablator areal density for thirteen imploded capsules, in the range 23 {+-} 10 to 58 {+-} 14 mg/cm{sup 2}, are comparable to values calculated in 1D radiation-hydrodynamic simulations, and measured by charged-particle techniques.

  9. Comprehensive Photometry of the Rings and 16 Satellites of Uranus with the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Karkoschka, Erich

    2001-05-01

    Photometric properties of 4 rings and 16 satellites of Uranus are presented, based on 41 Hubble Space Telescope images taken in 1997. Up to 25 filters per object covered the wavelength range 0.27-2 μm. The whole range of phase angles observable from Earth (0.03-3°) was probed. Reflectivities were calibrated on an absolute scale to typically 4% accuracy. Below 1 μm, derived geometric albedos of major satellites are typically 30% higher than previously reported due to previously unobserved steep upturns of the phase curve shortward of 0.2° phase angle, possibly caused by coherent backscatter. Portia is slightly oblong and Juliet and Belinda are very oblong based on their rotational lightcurves. Puck displays a weak spectral feature indicative of water ice absorption. Cordelia and Ophelia were recovered very close to the positions predicted from their gravitational influence on the ɛ ring. They have not been observed since 1986. Subtle color variations within the satellite system were confirmed. Throughout the uranian system, the slope of phase curves below 1° phase angle displays a strong correlation with the albedo and a strong anticorrelation with the slope at higher phase angles. Similar correlations were found for Hapke parameters. The brightness of 20 members of the uranian system is presented in functional form for a wide range of wavelengths, phase angles, and orbital longitudes.

  10. Bouncing and bursting in a wedge

    NASA Astrophysics Data System (ADS)

    Reyssat, Etienne; Cohen, Caroline; Quere, David

    2015-11-01

    Placed into an inhomogeneous confined medium, non-wetting drops tend to be expelled from the tightest regions, where their contact with the walls would be maximized. They preferentially explore more open areas which are favorable from the point of view of capillary energy. Following this principle, one may thus use the geometry of confined environments to control fluid droplets in various ways : displacing, filtering, fragmenting... In this communication, we present experimental results on the dynamics of Leidenfrost drops launched into a wedge formed by two quasi-horizontal glass plates. Influenced by the gradient of confinement, these non-wetting liquid pucks approach the apex of the wedge to a minimal distance where they bounce back. At higher impact velocity, we observe that drops tend to penetrate deeper into the wedge but often burst into a large number of small fragments. We also discuss ways to control the deviation of droplets from their initial trajectory. We propose scaling law analyses to explain the characteristics of the observed bouncing and bursting phenomena.

  11. Failure Criteria for FRP Laminates in Plane Stress

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Camanho, Pedro P.

    2003-01-01

    A new set of six failure criteria for fiber reinforced polymer laminates is described. Derived from Dvorak's fracture mechanics analyses of cracked plies and from Puck's action plane concept, the physically-based criteria, denoted LaRC03, predict matrix and fiber failure accurately without requiring curve-fitting parameters. For matrix failure under transverse compression, the fracture plane is calculated by maximizing the Mohr-Coulomb effective stresses. A criterion for fiber kinking is obtained by calculating the fiber misalignment under load, and applying the matrix failure criterion in the coordinate frame of the misalignment. Fracture mechanics models of matrix cracks are used to develop a criterion for matrix in tension and to calculate the associated in-situ strengths. The LaRC03 criteria are applied to a few examples to predict failure load envelopes and to predict the failure mode for each region of the envelope. The analysis results are compared to the predictions using other available failure criteria and with experimental results. Predictions obtained with LaRC03 correlate well with the experimental results.

  12. Implementation and Evaluation of Four Interoperable Open Standards for the Internet of Things.

    PubMed

    Jazayeri, Mohammad Ali; Liang, Steve H L; Huang, Chih-Yuan

    2015-01-01

    Recently, researchers are focusing on a new use of the Internet called the Internet of Things (IoT), in which enabled electronic devices can be remotely accessed over the Internet. As the realization of IoT concept is still in its early stages, manufacturers of Internet-connected devices and IoT web service providers are defining their proprietary protocols based on their targeted applications. Consequently, IoT becomes heterogeneous in terms of hardware capabilities and communication protocols. Addressing these heterogeneities by following open standards is a necessary step to communicate with various IoT devices. In this research, we assess the feasibility of applying existing open standards on resource-constrained IoT devices. The standard protocols developed in this research are OGC PUCK over Bluetooth, TinySOS, SOS over CoAP, and OGC SensorThings API. We believe that by hosting open standard protocols on IoT devices, not only do the devices become self-describable, self-contained, and interoperable, but innovative applications can also be easily developed with standardized interfaces. In addition, we use memory consumption, request message size, response message size, and response latency to benchmark the efficiency of the implemented protocols. In all, this research presents and evaluates standard-based solutions to better understand the feasibility of applying existing standards to the IoT vision. PMID:26402683

  13. Planetary nomenclature

    NASA Technical Reports Server (NTRS)

    Strobell, M. E.; Masursky, Harold

    1987-01-01

    In fiscal 1986, names were chosen for prominent features on the five previously known Uranian satellites and for features on the largest of the 10 satellites discovered by Voyager 2. The names of the five large satellites are taken mostly from Shakespeare, and most are spirits; therefore, Shakespearean and spirit themes were used to choose names for topographic features on the satellites. Crater names and most other feature names on Miranda, Oberon, and Titania are from Shakespeare; features on Ariel are named for bright spirits and those on Umbriel for dark, all taken from universal mythology. Preliminary coordinates for these features are derived from shaded relief maps of the satellites to be published in 1987. Orbital elements have been established for the 10 new satellites, and a paper describing this work is in progress; satellite positions are under review by Commission 16 of the IAU. The moon 1985 U1 is informally designated Puck. The nine small satellites discovered in 1986 are to be named for Shakespearean heroines; these names are to be listed in the 1987 edition of the Annual Gazetteer of Planetary Nomenclature.

  14. Jack Rabbit Pretest Shadowplate Drawings For TATB IHE Model Development

    SciTech Connect

    Hart, M M; McDaniel, D W

    2009-07-10

    The Jack Rabbit Pretest (PT) series consisted of 5 focused hydrodynamic experiments 2021E PT3, PT4, PT5, PT6, and PT7. They were fired in March and April of 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory, Livermore, California. These experiments measured deadzone formation and impulse gradients created during the detonation of TATB based insensitive high explosive. When setting up computer simulations of the Jack Rabbit Pretest series, the modeler or code developer can execute simulations with increasing degrees of refinement using detail found in the shadowplate design. The easiest way to get started is by treating the shadowplate in each experiment as a monolithic homogeneous piece of stainless steel. The simulation of detonation would begin as a point initiation below the center, bottom surface of the shadowplate. The detonation running through the ultrafine TATB booster can be simulated using program burn and then switched over to a reactive flow detonation model as the detonation front crosses the boundary into the main charge LX-17 IHE. A modeler wanting to further refine the simulation and progression of shock through the shadowplate can use the more detailed shadowplate design information presented in this document. The source drawings are included in Appendix A of this document. Their titles and drawing numbers are listed. Each experiment's shadowplate consists of two major components. A 303 stainless steel shape that defines the outer dimensions of shadowplate and a cylindrical 303 stainless steel detonator housing that is located in a closely machined pocket in the shape. The SIMPLE ASSY drawing accurately represents the dimensions of the outer shape, it's machined cylindrical pocket, and detonator body which is treated as a monolithic, homogeneous piece of stainless steel. The detonator body cross section shows an accurately dimensioned void where the slapper flyer barrel, LX-16 (pressed PETN) pellet, and pellet can flyer barrel are located. The FULL ASSY drawing accurately represents the dimensions of the outer shadowplate shape and it's machined pocket. The detonator dimensions and materials are detailed in cross section and exploded view. All diameters, thicknesses, and materials are called out in the drawing. You will notice that the detonator includes a multilayer slapper assembly with two layers of electrically insulating Kapton sandwiching the copper foil bridge circuit. The Kapton insulated circuit is sandwiched between two thin stainless steel sheets. This slapper assembly is secured to the detonator body with two screws. There is a 0.25 mm gap between the slapper assembly and the outer shadowplate shape. The stainless steel detonator body contains an off-center titanium wheel. This titanium wheel is secured to the detonator body with one screw and two pins to maintain position and orientation of the pellet can assembly in the center of the detonator body. The titanium wheel contains a tantalum/tungsten washer and pellet can assembly. The pellet can assembly consists of a pressed LX-16 initiator pellet contained in an extruded aluminum foil can. It may be useful for the modeler to include some of the details of the shadowplate and detonator design to further refine simulations of the Jack Rabbit Pretest experiments. These details may be relevant to the progression of shock originating from the PETN initiation pellet and ultrafine TATB booster that propagates through the shadowplate.

  15. Interfibre Failure Characterisation of Unidirectional and Triax Glass Fibre Non-Crimp Fabric Reinforced Epoxy Laminates

    NASA Astrophysics Data System (ADS)

    Laustsen, S.; Lund, E.; Kühlmeier, L.; Thomsen, O. T.

    2015-02-01

    The in-plane failure envelopes of unidirectional (UD) laminae in a UD and a Triax (0°, ±45°) laminate configuration have been investigated. The two laminate configurations have been characterised by testing off-axis specimens in uniaxial tension and compression at different angles relative to the fibre direction and further by Iosipescu shear tests. Strain gauge and Digital Image Correlation (DIC) measurements were used to measure the deformation states during loading, and to record the stress-strain responses to identify the initiation of failure and investigate the heterogeneity of the material and possible parasitic effects. A novel analysis methodology to determine the so-called `failure initiation strength' based on the second derivative of the stresses with respect to the strains has been adopted. The experimentally determined `failure initiation stresses' were compared with predictions from the commonly applied Maximum Stress, Tsai-Wu, and Puck failure criteria. From this work, a thorough comparison of the UD and Triax failure envelopes has been facilitated. It is shown that failure prediction for the Triax laminate based on the failure envelope derived from UD lamina tests may be too conservative in comparison with fitting a failure criterion directly to the Triax laminate test data. The latter approach implies that the Triax laminate is considered as a single lamina with homogenised properties, which in principle violates the theoretical background of the considered failure criteria, since these are established to predict failure for a UD lamina. However, the simple homogenisation is shown to be a useful design oriented approach for providing a simple estimation of the onset of failure in laminate configurations composed of e.g., multiple layers of Triax. Thus, a reliable and efficient approach is offered for the structural integrity assessment, which takes the non-crimp fabric configurations directly or `as delivered' into account.

  16. High-density grids for efficient data collection from multiple crystals

    DOE PAGESBeta

    Baxter, Elizabeth L.; Aguila, Laura; Alonso-Mori, Roberto; Barnes, Christopher O.; Bonagura, Christopher A.; Brehmer, Winnie; Brunger, Axel T.; Calero, Guillermo; Caradoc-Davies, Tom T.; Chatterjee, Ruchira; et al

    2015-11-03

    Higher throughput methods to mount and collect data from multiple small and radiation-sensitive crystals are important to support challenging structural investigations using microfocus synchrotron beamlines. Furthermore, efficient sample-delivery methods are essential to carry out productive femtosecond crystallography experiments at X-ray free-electron laser (XFEL) sources such as the Linac Coherent Light Source (LCLS). To address these needs, a high-density sample grid useful as a scaffold for both crystal growth and diffraction data collection has been developed and utilized for efficient goniometer-based sample delivery at synchrotron and XFEL sources. A single grid contains 75 mounting ports and fits inside an SSRL cassettemore » or uni-puck storage container. The use of grids with an SSRL cassette expands the cassette capacity up to 7200 samples. Grids may also be covered with a polymer film or sleeve for efficient room-temperature data collection from multiple samples. New automated routines have been incorporated into theBlu-Ice/DCSSexperimental control system to support grids, including semi-automated grid alignment, fully automated positioning of grid ports, rastering and automated data collection. Specialized tools have been developed to support crystallization experiments on grids, including a universal adaptor, which allows grids to be filled by commercial liquid-handling robots, as well as incubation chambers, which support vapor-diffusion and lipidic cubic phase crystallization experiments. Experiments in which crystals were loaded into grids or grown on grids using liquid-handling robots and incubation chambers are described. As a result, crystals were screened at LCLS-XPP and SSRL BL12-2 at room temperature and cryogenic temperatures.« less

  17. Comparing Phoebe's 2005 opposition surge in four visible light filters

    NASA Astrophysics Data System (ADS)

    Miller, C.; Verbiscer, A. J.; Chanover, N. J.; Holtzman, J. A.; Helfenstein, P.

    2011-04-01

    We observed Phoebe for 13 nights over a period of 55 days before, during, and after the 2005 Saturn opposition with the New Mexico State University (NMSU) 1-m telescope at Apache Point Observatory (APO) in Sunspot, NM and characterized the width and magnitude of Phoebe's opposition surge in BVRI filters. Our observations cover a phase angle range of 4.87 to 0.0509. We use a Hapke reflectance model incorporating shadow hiding and coherent backscatter to investigate the wavelength dependence of Phoebe's opposition surge. We find a significant opposition surge magnitude of 55-58% between phase angles of 5 and 0. We find the strongest opposition surge for phase angles less than 2 in the I-band. The coherent backscatter angular width is on the order of 0.50. We find Phoebe's albedo to be spectrally flat within our error limits, with a B-band albedo of 0.0855 0.0031, a V-band albedo of 0.0856 0.0023, an R-band albedo of 0.0843 0.0020, and an I-band albedo of 0.0839 0.0023. We compare Phoebe's albedo, color, and opposition surge magnitudes and slopes with those of other outer solar system bodies and find similarities to Centaurs, Nereid, Puck, and Comets 19P/Borrelly, 9P/Tempel 1, and 81P/Wild 2. We find that this comparison supports the idea that Phoebe originated in the Kuiper Belt. We also discuss the caveats of using results from a Hapke reflectance model to derive specific surface particle properties.

  18. Rapid, Non-Mechanical, Damage Free Figuring Of Optical Surfaces Using Plasma Assisted Chemical Etching (PACE): Part Ii Theory & Process Control

    NASA Astrophysics Data System (ADS)

    Zarowin, C. B.; Bollinger, L. D.

    1989-01-01

    We describe an application of Plasma Assisted Chemical Etching (PACE) to rapid and controllable figuring and smoothing of optical surfaces without mechanical contact. This removes the usual constraints on the design of optical elements imposed by mechanical pro-cesses, such as substrate deformation, edge distortion and subsurface damage or contamination. This process employs a process originally developed to pattern microelectronic circuits by ion enhanced chemical etching of a solid (Si02, Si, Al, Au, etc.) through a relatively nonerodeable photolithographically patterned mask1,-2. The PACE process shapes the optical surface by removing material in a small area under a confined reactive gas plasma (a "puck") moved over this surface. Rates of removal of such processes in microelectronic applications are as high as 10 pm per minute and are very accurately controllable and repeatable. The removal "footprint" of PACE may be varied during the process and it inherently smooths or polishes while exposing a virgin surface free of process generated contamination and subsurface damage. It can operate in two modes: (1) in "contact" with the plasma, where the chemical reaction is driven by the kinetic energy given up at the reacting surface by short lived species such as ions; and (2) downstream of the plasma, by the stored energy freed at the surface by longer lived species such as excited metastable neutrals. Since control of this process is so important to this application, we sketch the generic physics and chemi hi stry1,2 of the PACE figuring and smoothing process, identifying the quantitative relations between the plasma and chemical parameters that control it:rf power density reactive gas pressure reactive gas flow the reactor surface temperatures and the pertinent transport chemistry.

  19. Habitat-related patterns of soft-bottom macrofaunal assemblages in a brackish, low-diversity system (southern Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Sokołowski, Adam; Ziółkowska, Marcelina; Zgrundo, Aleksandra

    2015-09-01

    Coastal areas provide a high variety of sedimentary habitats that influence the structure of resident fauna even on small geographical scales. Therefore, examinations of spatial variations in benthic assemblages require background knowledge of the environmental and biotic heterogeneity of habitats in order to understand ecological processes in such areas. The effect of habitat-related abiotic and biological variables on macrofaunal benthic assemblages was studied seasonally in 2010 and 2011 in the brackish, semi-enclosed Puck Lagoon (Gulf of Gdańsk, southern Baltic Sea). Based on macrophytal biomass, two discrete benthic regions were identified in the lagoon: a region of large biomass and a region of few macrophytes. The quality of the surface sediment organic matter (measured as C/Nsed ratio), depth, and benthic macrophyte composition accounted for within-region variation, which led to the identification of four habitats. Shallow sandy sediments with low C/Nsed ratios provide high quality sedimentary food for animals that, together with species-rich, dense macrophyte vegetation, support diverse assemblages. High C/Nsed ratios and peat outcrops in shallow sands exert a negative effect on macrofaunal diversity. Two deeper sandy habitats with less massive, species-poor vegetation tend to host distinct faunal assemblages of higher abundance and biomass. The importance of benthic vegetation for macrofaunal assemblages in the southern Baltic Sea is suggested to stem from its complex spatial structure that offers a number of microniches for infaunal and epifaunal species. The effect of macrophytes on benthic faunal assemblages was consistent throughout most of the year with the strongest influence in summer when macrophytes reached the highest biomass.

  20. High-density grids for efficient data collection from multiple crystals.

    PubMed

    Baxter, Elizabeth L; Aguila, Laura; Alonso-Mori, Roberto; Barnes, Christopher O; Bonagura, Christopher A; Brehmer, Winnie; Brunger, Axel T; Calero, Guillermo; Caradoc-Davies, Tom T; Chatterjee, Ruchira; Degrado, William F; Fraser, James S; Ibrahim, Mohamed; Kern, Jan; Kobilka, Brian K; Kruse, Andrew C; Larsson, Karl M; Lemke, Heinrik T; Lyubimov, Artem Y; Manglik, Aashish; McPhillips, Scott E; Norgren, Erik; Pang, Siew S; Soltis, S M; Song, Jinhu; Thomaston, Jessica; Tsai, Yingssu; Weis, William I; Woldeyes, Rahel A; Yachandra, Vittal; Yano, Junko; Zouni, Athina; Cohen, Aina E

    2016-01-01

    Higher throughput methods to mount and collect data from multiple small and radiation-sensitive crystals are important to support challenging structural investigations using microfocus synchrotron beamlines. Furthermore, efficient sample-delivery methods are essential to carry out productive femtosecond crystallography experiments at X-ray free-electron laser (XFEL) sources such as the Linac Coherent Light Source (LCLS). To address these needs, a high-density sample grid useful as a scaffold for both crystal growth and diffraction data collection has been developed and utilized for efficient goniometer-based sample delivery at synchrotron and XFEL sources. A single grid contains 75 mounting ports and fits inside an SSRL cassette or uni-puck storage container. The use of grids with an SSRL cassette expands the cassette capacity up to 7200 samples. Grids may also be covered with a polymer film or sleeve for efficient room-temperature data collection from multiple samples. New automated routines have been incorporated into the Blu-Ice/DCSS experimental control system to support grids, including semi-automated grid alignment, fully automated positioning of grid ports, rastering and automated data collection. Specialized tools have been developed to support crystallization experiments on grids, including a universal adaptor, which allows grids to be filled by commercial liquid-handling robots, as well as incubation chambers, which support vapor-diffusion and lipidic cubic phase crystallization experiments. Experiments in which crystals were loaded into grids or grown on grids using liquid-handling robots and incubation chambers are described. Crystals were screened at LCLS-XPP and SSRL BL12-2 at room temperature and cryogenic temperatures. PMID:26894529