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1

Simulation of puck flight to determine spectator safety for various ice hockey board heights  

Microsoft Academic Search

The boards of ice hockey rinks are equipped with protective glass to prevent the spectators from being hit by the puck. According\\u000a to international rules, the minimum height of the board with protective glass is 197 cm. This is not high enough to protect\\u000a the spectators from puck-related injuries, and severe accidents have occurred in the past. This study investigates

H. Böhm; C. Schwiewagner; V. Senner

2007-01-01

2

The Impact of Puck Possession and Location on Ice Hockey Strategy  

Microsoft Academic Search

I create a state space within the game of ice hockey by noting which team has possession, and in what location of the rink the puck is located. This space is used to model the game as a semi-Markov process, as data from a series of games in 2004-2005 NCAA play suggest that the system cannot be modeled as a

Andrew C. Thomas

2006-01-01

3

Holston-Pantex LX17 formulation comparison  

Microsoft Academic Search

A comparison was made between a 1270 kg LX-17 lot formulated at Holston and smaller LX-17 lots formulated at Pantex. Chemical, thermal, mechanical sensitivity and physical property analyses were compared. The Holston LX-17 lot pressed to a slightly higher density, had less growth, and gave a higher strain level. Otherwise, there were no significant differences found between the Holston and

Neff

1981-01-01

4

The Puck Stops Here  

NSDL National Science Digital Library

After learning about transfer of energy, specifically the loss of kinetic energy to friction, students get a chance to test friction. In groups they are given a wooden block, different fabrics, and weights and asked to design the "best" puck. The class first needs to define what makes the "best" puck. Each group should realize that the most desirable puck will travel the furthest, thus the puck with the least amount of friction. In the context of hockey the "best" puck is the one that travels farthest and loses the least kinetic energy to friction. Students then need to apply their knowledge of friction to design a new optimal puck for the National Hockey League. The friction is the transfer from kinetic energy to heat energy.

Engineering K-Ph.d. Program

5

Air Gap Effects in LX17  

Microsoft Academic Search

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

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

2005-01-01

6

Air Gap Effects in LX-17  

SciTech Connect

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.

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

7

LX-17 Deflagration at High Pressures and Temperatures  

SciTech Connect

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.

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

2006-10-23

8

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

SciTech Connect

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.

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

2010-02-03

9

Detonation Shock Dynamics (DSD) Calibration for LX-17  

SciTech Connect

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.

Aslam, Tariq D [Los Alamos National Laboratory

2012-04-24

10

Temperature-dependent shock initiation of LX17 explosive  

Microsoft Academic Search

LX-17 samples, heated to temperatures up to 250 C, were impacted by 3 to 10-mm-wide, 50.8-mm-long strips of 0.13-mm-thick Kapton polyimide film at velocities up to 7.7 km\\/s. The Kapton strips were laminated onto a thin aluminum bridge foil and were launched to the desired velocity by discharging a capacitor bank through the foil, causing the foil to explode. The

R. S. Lee; H. H. Chau; R. L. Druce; K. Moua

1995-01-01

11

Dead Zones in LX17 and PBX 9502  

Microsoft Academic Search

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

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

2005-01-01

12

Dead Zones in LX-17 and PBX 9502  

SciTech Connect

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.

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

13

Science of NHL Hockey: Force, Impulse & Collisions  

NSDL National Science Digital Library

NHL hockey pucks are made of vulcanized rubber and weigh between 5.5 and 6 ounces (160 - 170 g). During a game, every movement of the puck follows the laws of physics and illustrates the concepts of force, impulse and collisions. "Science of NHL Hockey" is a 10-part video series produced in partnership with the National Science Foundation and the National Hockey League.

Learn, Nbc

2010-10-07

14

Science of NHL Hockey: Vectors  

NSDL National Science Digital Library

NHL players are celebrated for their ability to pass the puck quickly and accurately as play moves from one end of the ice to the other. These pinpoint passes, requiring both magnitude and direction, are perfect examples of velocity vectors. "Science of NHL Hockey" is a 10-part video series produced in partnership with the National Science Foundation and the National Hockey League.

Learn, Nbc

2010-10-07

15

LX-17 Corner-Turning and Reactive Flow Failure  

SciTech Connect

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.

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

2004-03-11

16

Plutonium Immobilization Puck Handling  

SciTech Connect

The Plutonium Immobilization Project (PIP) will immobilize excess plutonium and store the plutonium in a high level waste radiation field. To accomplish these goals, the PIP will process various forms of plutonium into plutonium oxide, mix the oxide powder with ceramic precursors, press the mixture into pucks, sinter the pucks into a ceramic puck, load the pucks into metal cans, seal the cans, load the cans into magazines, and load the magazines into a Defense Waste Processing Facility (DPWF) canister. These canisters will be sent to the DWPF, an existing Savannah River Site (SRS) facility, where molten high level waste glass will be poured into the canisters encapsulating the ceramic pucks. Due to the plutonium radiation, remote equipment will perform these operations in a contained environment. The Plutonium Immobilization Project is in the early design stages and the facility will begin operation in 2005. This paper will discuss the Plutonium Immobilization puck handling conceptual design and the puck handling equipment testing.

Kriikku, E.

1999-01-26

17

The Science of Hockey  

NSDL National Science Digital Library

This site is a Sports Science resource where users read about National Hockey League players, coaches from the San Jose Sharks, and physicists and chemists. Included is information about ice, the qualities that make it a unique playing surface, why ice is slippery, mechanics of ice skating, hockey equipment, NHL goals, how players can shoot the puck over one hundred miles an hour, checking using physical force, and physical fitness. Links to other sites and mathematics formulas that show how much energy is expended in an open ice hit can also be found.

Spadaccini, Jim

2004-01-01

18

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)

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.

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

2000-01-01

19

Velocity of Spherically-Diverging Detonation Waves in RX-26-AF, LX-17 and LX-10.  

National Technical Information Service (NTIS)

The velocity of spherically-diverging detonation waves was measured in RX-26-AF, LX-17 and LX-10 explosives at 20 exp 0 C and -54 exp 0 C for detonation wave radii from 13 to 50 mm. At the smaller radii the measured velocities were lower than published st...

K. L. Bahl R. C. Weingart R. S. Lee

1983-01-01

20

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

SciTech Connect

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.

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

2008-02-05

21

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

SciTech Connect

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.

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

2007-05-30

22

Characterizing Detonating LX-17 Charges Crossing a Transverse Air Gap with Experiments and Modeling  

NASA Astrophysics Data System (ADS)

Experiments were performed using detonating LX-17 (92.5% TATB, 7.5% Kel-f by weight) charges with various width transverse air gaps both with and without manganin peizoresistive in-situ gauges present. The experiments, performed with 25 mm diameter by 25 mm long LX-17 pellets with the transverse air gap in between, showed that transverse gaps up to about 3 mm could be present without causing the detonation wave to fail to continue as a detonation. A JWL++/Tarantula code was utilized to model the results and compare with the in-situ gauge records with reasonable agreement to the experimental data. This work will present the experimental details as well as comparison to the model results. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Lauderbach, Lisa M.; Souers, P. Clark; Garcia, Frank; Vitello, Peter; Vandersall, Kevin S.

2009-06-01

23

CHARACTERIZING DETONATING LX-17 CHARGES CROSSING A TRANSVERSE AIR GAP WITH EXPERIMENTS AND MODELING  

SciTech Connect

Experiments were performed using detonating LX-17 (92.5% TATB, 7.5% Kel-F by weight) charges with various width transverse air gaps with manganin peizoresistive in-situ gauges present. The experiments, performed with 25 mm diameter by 25 mm long LX-17 pellets with the transverse air gap in between, showed that transverse gaps up to about 3 mm could be present without causing the detonation wave to fail to continue as a detonation. The Tarantula/JWL{sup ++} code was utilized to model the results and compare with the in-situ gauge records with some agreement to the experimental data with additional work needed for a better match to the data. This work will present the experimental details as well as comparison to the model results.

Lauderbach, L M; Souers, P C; Garcia, F; Vitello, P; Vandersall, K S

2009-06-26

24

Explosive Model Tarantula 4d\\/JWL++ Calibration of LX17  

Microsoft Academic Search

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

P C Souers; P A Vitello

2008-01-01

25

Velocity of spherically-diverging detonation waves in RX26AF, LX17 and LX10  

Microsoft Academic Search

The velocity of spherically-diverging detonation waves was measured in RX-26-AF, LX-17 and LX-10 explosives at 20°C and -54°C for detonation wave radii from 13 to 50 mm. At the smaller radii the measured velocities were lower than published steady detonation velocities by as much as 4%. The detonation velocities measured at -54°C were usually higher than those measured at room

K. L. Bahl; R. S. Lee; R. C. Weingart

1983-01-01

26

Effect of confinement and thermal cycling on the shock initiation of LX17  

Microsoft Academic Search

The shock initiation of the insensitive high explosive LX-17, which contains 92.5% triaminotrinitrobenzene (TATB) and 7.5% Kel-F binder, was studied under two simulated accident conditions: initially confined charges were heated to 250°C and shocked; and unconfined charges were thermally cycled between 25° and 250°C and shocked. Previous research on unconfined TATB-based explosives heated to 250°C revealed increased shock sensitivity. This

P. A. Urtiew; C. M. Tarver; J. L. Maienschein; W. C. Tao

1996-01-01

27

Air Gaps, Size Effect, and Corner-Turning in Ambient LX17  

Microsoft Academic Search

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

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

2007-01-01

28

Air Gaps, Size Effect, and Corner-Turning in Ambient LX17  

Microsoft Academic Search

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

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

2008-01-01

29

Science of NHL Hockey: Projectile Motion  

NSDL National Science Digital Library

Unlike a slap shot, an NHL wrist shot isn�t about brute power. It�s about precision � putting the puck in the exact spot where the goalie can�t reach it. A wrist shot is also a perfect example of what�s known in physics as projectile motion. "Science of NHL Hockey" is a 10-part video series funded by the National Science Foundation and produced in partnership with the National Hockey League.

Learn, Nbc

2010-10-07

30

Kick Dis Power Puck  

NASA Astrophysics Data System (ADS)

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.

Carlson, John E.

2004-03-01

31

Velocity of spherically-diverging detonation waves in RX-26-AF, LX-17 and LX-10  

SciTech Connect

The velocity of spherically-diverging detonation waves was measured in RX-26-AF, LX-17 and LX-10 explosives at 20/sup 0/C and -54/sup 0/C for detonation wave radii from 13 to 50 mm. At the smaller radii the measured velocities were lower than published steady detonation velocities by as much as 4%. The detonation velocities measured at -54/sup 0/C were usually higher than those measured at room temperature. These results indicate that a significant part of the excess transit time observed when an explosive is initiated by a point or hemispherical detonator may be due to a low detonation velocity.

Bahl, K.L.; Lee, R.S.; Weingart, R.C.

1983-07-15

32

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

SciTech Connect

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.

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

1993-12-01

33

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

SciTech Connect

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.

Souers, P C; Vitello, P A

2008-09-30

34

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

35

End-Effector Development for the PIP Puck Handling Robot  

SciTech Connect

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.

Fowley, M.D.

2001-01-31

36

End-Effector Development for the PIP Puck Handling Robot  

SciTech Connect

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.

Fowley, M.D.

2001-01-03

37

Field Hockey  

MedlinePLUS

... personally. Let the referees handle the situation, and never start a fight with another player. There's nothing particularly dangerous about field hockey, and it's been played for thousands of years. But injuries can happen if people don't pay attention to what's ...

38

Supra-Compression of LX-07, LX-17, PBX-9404, and RX-26-AF and the Equations of State of the Detonation Products.  

National Technical Information Service (NTIS)

Shock velocity vs input pressure in the range of 32 to 112 GPa has been measured for LX-07, LX-17, PBX-9404, and RX-26-AF. The average shock velocity for the first 2.8-mm of run was found to be within one percent of that for the run from 2.0 to 4.8-mm. Su...

L. Green E. Lee A. Mitchell C. Tarver

1985-01-01

39

Hockey, iPads, and Projectile Motion in a Physics Classroom  

ERIC Educational Resources Information Center

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…

Hechter, Richard P.

2013-01-01

40

Supra-compression of LX07, LX17, PBX9404, and RX26AF and the equations of state of the detonation products  

Microsoft Academic Search

Shock velocity vs input pressure in the range of 32 to 112 GPa has been measured for LX-07, LX-17, PBX-9404, and RX-26-AF. The average shock velocity for the first 2.8-mm of run was found to be within one percent of that for the run from 2.0 to 4.8-mm. Supra-compressive states of PBX-9404 were reflected to higher pressures by a copper

L. Green; E. Lee; A. Mitchell; C. Tarver

1985-01-01

41

Hockey Injury Prevention  

MedlinePLUS

... more than 500,000 individuals are involved in youth hockey through its organization alone. Both boys and girls ... overly aggressive play. Top of page Team Play Youth hockey is usually divided into two types of teams: ...

42

Physiknobelei Puck auf rotierender Erde - ein Nachtrag  

NASA Astrophysics Data System (ADS)

Die erste Aufgabe unserer Rubrik PhysiKnobelei zu dem Puck auf rotierender Erde war sehr knifflig. Dennoch bekamen wir zahlreiche richtige Einsendungen. Einige Leser haben sogar Computerprogramme zur Lösung geschrieben. Herr Kuhn aus Renningen ist auf ein besonders interessantes Phänomen gestoßen, das wir hier gerne vorstellen möchten.

Kuhn, Ulrich

2003-05-01

43

Science of NHL Hockey  

NSDL National Science Digital Library

NBC Learn and NBC Sports, in partnership with the National Science Foundation and the National Hockey League, explore the science and math behind professional hockey. Featuring game footage and contributions from NHL players and scientists, the 10 part series uses hockey to demonstrate such key concepts as Newton's Laws, kinematics, collisions, projectile motion, vectors and basic geometry. Each video has related lesson plans that include classroom and extended activities.

2012-03-06

44

Supra-compression of LX-07, LX-17, PBX-9404, and RX-26-AF and the equations of state of the detonation products  

SciTech Connect

Shock velocity vs input pressure in the range of 32 to 112 GPa has been measured for LX-07, LX-17, PBX-9404, and RX-26-AF. The average shock velocity for the first 2.8-mm of run was found to be within one percent of that for the run from 2.0 to 4.8-mm. Supra-compressive states of PBX-9404 were reflected to higher pressures by a copper barrier and the velocity in the copper measured. They were also rarefied by a magnesium barrier and the velocity in the magnesium measured. Equations of state derived for the reaction products of these explosives and normalized to accepted C-J pressures do not adequately predict measurements at pressures substantially greater than detonation pressure, normalization to lower than accepted C-J pressures is required to fit the data. The C-J state defined by the supra-compressive experiments appears to be different from the C-J state defined by the usual C-J pressure measurement.

Green, L.; Lee, E.; Mitchell, A.; Tarver, C.

1985-06-27

45

Remote handling in the Plutonium Immobilization Project: Puck packaging  

SciTech Connect

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.

Kriikku, E.

1999-07-01

46

Slapshot Physics: Hockey  

NSDL National Science Digital Library

The following resource is fromLessonopoly, which has created student activities and lesson plans to support the video series, Science of the Olympic Winter Games, created by NBC Learn and the National Science Foundation. Featuring exclusive footage from NBC Sports and contributions from Olympic athletes and NSF scientists, the series will help teach your students valuable scientific concepts. In this particular lesson, students will learn about hockey, the slapshot, and techniques such as force, weight, and speed. Students will play a simulated game of hockey and try to make a slapshot. Students will also practice the scientific method by designing and conducting their own experiment with the materials used in the simulation.

2010-01-01

47

The Science of Hockey  

NSDL National Science Digital Library

The Science of Hockey is the first in a series of "Sports Science" resources developed by the Exploratorium. This site takes you inside the game: you'll hear from NHL players and coaches from the San Jose Sharks, as well as leading physicists and chemists.

48

A Hockey Hero  

ERIC Educational Resources Information Center

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…

Bolduc, Matt

2009-01-01

49

[Injuries in field hockey].  

PubMed

Frequency and mechanisms of injuries in field hockey are evaluated in a retrospective study of 322 players. Each athlete sustains 0.6 (female) respectively 1.0 (male) injuries per season on the average, mostly minor lesions. Severe injuries are mostly due to the playing surface; especially astroturf seems to be dangerous. The risk during match exceeds the risk during practice by a factor of 10.36% are typical field hockey injuries as they are caused by ball or stick. 62% of the lesions are related to the lower limb, 19% to the upper limb (mainly hand and fingers), and 19% to head and trunk. The data allow to draw conclusions concerning preventive measures. PMID:8066540

Eggers-Ströder, G; Hermann, B

1994-06-01

50

Plutonium Immobilization Project Can Loading and Puck Handling Vision Software  

SciTech Connect

The U.S. Department of Energy will immobilize excess plutonium in the proposed Plutonium Immobilization Plant (PIP) at the Savannah River Site (SRS) as part of a two track approach for the disposition of weapons-usable plutonium. The Department of Energy is funding the development and testing effort for the PIP being conducted by Lawrence Livermore National Laboratory (LLNL), Westinghouse Savannah River Company (WSRC), Pacific Northwest National Laboratory (PNNL), and Argonne National Laboratory (ANL). The PIP will utilize the ceramic can-in-canister technology in a process that mixes plutonium and uranium with ceramic formers and neutron absorbers, presses the mixture into a ceramic puck-like form, and sinters the pucks in a furnace. Once sintered, the pucks are loaded into cans, then cans are placed into magazines, and magazines are inserted into large canisters. The canisters will subsequently be filled with high-level waste glass in the Defense Waste Processing Facility for eventual disposal in a geologic repository. The PIP project is currently being suspended due to budget constraints. The suspension requires documenting the current status of all systems under development including the Can Loading Vision System and the Puck Handling Vision System. This report provides this documentation.

Kriikku, E.

2001-09-10

51

Science of NHL Hockey: Kinematics  

NSDL National Science Digital Library

NHL skaters can reach speeds in excess of 20 miles (32km) per hour, and during some short bursts approach 30 miles (48 km) per hour. Kinematics, the branch of classical mechanics, helps describe a player's movement across the ice by defining his position, velocity and acceleration. "Science of NHL Hockey" is a 10-part video series produced in partnership with the National Science Foundation and the National Hockey League.

Learn, Nbc

2010-10-07

52

A to Z Encyclopaedia of Ice Hockey  

NSDL National Science Digital Library

Developed by the UK-based Stewart Roberts and Phil Stamp, this huge compendium of ice hockey information (over 14,000 entries) is all the more notable for its international scope. No NHL-centricity here. In fact, the only Americans and Canadians in the site's Hall of Fame are in the International Ice Hockey Federation section. A constant work-in-progress, this site is a seemingly bottomless well of hockey trivia and lore. Need to know the Attendance Averages for Finnish Division 1 hockey? The winner of the 1997 Croation hockey championship? What the "A" on players' jerseys means? Its all here and much, much more.

1998-01-01

53

Massachusetts Special Olympics Poly Hockey.  

ERIC Educational Resources Information Center

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…

Morrissey, Jim

54

Science of NHL Hockey: Mass, Volume & Density  

NSDL National Science Digital Library

NHL fans might be surprised to learn that the ice surface at a hockey rink is only about one inch thick. Scientists and ice technicians explain the science and math that goes into building and maintaining this surface through the long NHL season. "Science of NHL Hockey" is a 10-part video series produced in partnership with the National Science Foundation and the National Hockey League.

Learn, Nbc

2010-10-07

55

Visual Attentional Orienting in Developing Hockey Players.  

ERIC Educational Resources Information Center

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)

Enns, James T.; Richards, James C.

1997-01-01

56

Science of NHL Hockey: Statistics & Averages  

NSDL National Science Digital Library

Being a top goalie in the NHL takes more than quick reflexes and nerves of steel, it also requires a firm grip on the numbers. Namely, the key averages and statistics of goaltending. "Science of NHL Hockey" is a 10-part video series produced in partnership with the National Science Foundation and the National Hockey League.

Learn, Nbc

2010-10-07

57

Science of NHL Hockey: Work, Energy & Power  

NSDL National Science Digital Library

The slapshot is one of the fastest projectiles in team sports. In order to generate a 100 mile-per-hour (160 kph) slapper, NHL players depend on three important physics concepts: work, energy and power. "Science of NHL Hockey" is a 10-part video series funded by the National Science Foundation and produced in partnership with the National Hockey League.

Learn, Nbc

2010-10-07

58

Injury patterns among female field hockey players  

Microsoft Academic Search

MURTAUGH, K. Injury patterns among female field hockey players. Med. Sci. Sports Exerc., Vol. 33, No. 2, 2001, pp. 201-207. Purpose: To examine injury patterns among female field hockey players and to broaden the current base of knowledge by identifying the injury rates of different playing positions. It was hypothesized that goalkeepers would have the highest rate of injury, followed

KAREN MURTAUGH

2001-01-01

59

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

PubMed Central

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

McIntosh, A; Janda, D

2003-01-01

60

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

61

Hockey Greats Retire En Masse  

NSDL National Science Digital Library

Mark of distinctionhttp://sportsillustrated.cnn.com/2005/writers/michael_farber/09/12/messier.retires/index.htmlCentre Ron Francis retires after 23 distinguished NHL seasonshttp://www.canada.com/edmonton/edmontonjournal/news/sports/story.html?id=cda782b9-2192-4783-8365-7acc1bc6b656Another NHL star quits; Francis retireshttp://msnbc.msn.com/id/9340488/ESPN.com: NHL Statisticshttp://sports.espn.go.com/nhl/statisticsHockey Hall of Famehttp://www.hhof.com/index.htmAfter a long strike, the National Hockey League is gearing up for the 2005-2006 season in earnest. Regrettably, the game will be without two of its standout players, as both Mark Messier of the New York Rangers and Ron Francis of the Toronto Maple Leafs announced their retirements this week. Messier began his 25-season career with his hometown Edmonton Oilers in 1979, and led the team to five Stanley Cup victories. Of course, many will also remember his many fine years of play with the Rangers, where he also led them to victory in the 1994 Stanley Cap as well. Messier made his announcement on a conference call because as he remarked, "no one wants to see a blubbering idiot at the podium".

2005-01-01

62

Cardiac arrhythmia detection using combination of heart rate variability analyses and PUCK analysis.  

PubMed

This paper presents cardiac arrhythmia detection using the combination of a heart rate variability (HRV) analysis and a "potential of unbalanced complex kinetics" (PUCK) analysis. Detection performance was improved by adding features extracted from the PUCK analysis. Initially, R-R interval data were extracted from the original electrocardiogram (ECG) recordings and were cut into small segments and marked as either normal or arrhythmia. HRV analyses then were conducted using the segmented R-R interval data, including a time-domain analysis, frequency-domain analysis, and nonlinear analysis. In addition to the HRV analysis, PUCK analysis, which has been implemented successfully in a foreign exchange market series to characterize change, was employed. A decision-tree algorithm was applied to all of the obtained features for classification. The proposed method was tested using the MIT-BIH arrhythmia database and had an overall classification accuracy of 91.73%. After combining features obtained from the PUCK analysis, the overall accuracy increased to 92.91%. Therefore, we suggest that the use of a PUCK analysis in conjunction with HRV analysis might improve performance accuracy for the detection of cardiac arrhythmia. PMID:24110032

Mahananto, Faizal; Igasaki, Tomohiko; Murayama, Nobuki

2013-01-01

63

PhET Simulation: Electric Field Hockey  

NSDL National Science Digital Library

This webpage contains an activity that allows users to guide a charged object, or "puck", through a maze using the electric field created by point charges placed by the user. Options exist to control the mass and sign of the charge of the puck. There are four levels of difficulty that change the barrier placement. Barriers do not affect the fields, only define the path of the puck. The user can view a vector representation of the electric field, as well as trace the path of the puck. After each attempt the user may move the existing charge or place more charges and try again. This activity gives users an immediate experience with the interaction between fields and charges. The page also contains samples of learning goals as well as user-submitted ideas and activities for use with the simulation. This simulation is part of a large and growing collection. It has been designed using principles from physics education research and refined based on student interviews.

Project, Physics E.

2006-10-31

64

Continuum Limit and Renormalization of Market Price Dynamics Based on PUCK Model  

NASA Astrophysics Data System (ADS)

We consider the new type of stochastic model of market pricewhich is originally proposed by M. Takayasu et al. [Physica A 370, (2006), 91] and is called PUCK model as the abbreviation of Potentials of Unbalanced Complex Kinetics model. It is shown that the Langevin equation with fluctuating viscosity and mass is derived as a continuous limit of this model. We also solve the macroscopic limit of PUCK model using a renormalization formulation based on moving average showing that there are four possible macro-limit behaviors of markets; exponential growth, double-exponential growth, oscillatory divergence and stationary state. The macroscopic stationary state includes random walk type fluctuations in microscopic scale.

Takayasu, M.; Takayasu, H.

65

Internet broadcast of hockey: a scale prototype  

NASA Astrophysics Data System (ADS)

We present a system for the broadcast of hockey games over the internet. The system allows users to experience the hockey game while it is in progress. Our system uses generic content description servers that acquire information from an external source, process it, and serve the processed data to client systems. Dynamic configuration of the servers allows us to use them in a variety of roles. For example, video information servers, like an MPEG-7 camera, produce XML documents that describe the motion of objects in the scene in addition to unprocessed video. Unlike an MPEG-7 camera, our video information servers interact with client systems, and can change their behavior through dynamic configuration. In an alternate configuration, a content description server acts as a game server in our hockey broadcast system. The game server forms an environment model that encapsulates the state of the hockey game and serves data from the model to clients. We developed and tested our system using a 1/32-scale model of a hockey rink. Early results using data acquired at a real rink indicate that the system performs as expected.

Boyd, Jeffrey E.; Sayles, Maxwell; Olsen, Luke; Tarjan, Paul

2003-12-01

66

Body Checking in Pee Wee Hockey.  

ERIC Educational Resources Information Center

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

Roy, Michel-Andre; And Others

1989-01-01

67

Ice hockey injuries: incidence, nature and causes.  

PubMed Central

In this prospective study, we have investigated incidence of injuries of different severity, types of injury, and mechanisms of injury during ice hockey games. All twelve Swedish elite hockey teams were observed during the season 1988-1989 when a total number of 664 games were played. There was a total number of 285 injuries, of which the majority were minor (61%) and only 9% were classified as major. Seventy-four per cent of the injuries occurred during games and 26% during practice. The overall incidence of injury was 53.0 per 1000 player-game hours. Eighty-five per cent of injuries were caused by trauma and 15% by over-use. Injuries were most often localized to the head/face (39%) or the lower limb (32%). Most injuries resulted from stick contact or player contact including checking. A reduction of minor and moderate injuries should be possible by stricter enforcement of the hockey rules, and more widespread use of visors.

Tegner, Y; Lorentzon, R

1991-01-01

68

Science of NHL Hockey: Newton's Three Laws of Motion  

NSDL National Science Digital Library

Whether they are sprinting down the ice, smashing into the boards or stopping on a dime, NHL players display an amazing mix of speed and strength. These athletic moves also provide great examples of Newton�s Three Laws of Motion. "Science of NHL Hockey" is a 10-part video series produced in partnership with the National Science Foundation and the National Hockey League.

Learn, Nbc

2010-10-07

69

Floor Hockey---Is It a Safe Sport for Schools?  

ERIC Educational Resources Information Center

Guidelines under which floor hockey should be taught to prevent avoidable injuries are presented. Three court cases involving floor hockey related injuries are reviewed, and issues of responsibility and liability on the part of physical educators and schools are discussed. (IAH)

Gray, Gary R.

1989-01-01

70

Bodychecking rules and concussion in elite hockey.  

PubMed

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

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

2013-01-01

71

A systematic video analysis of National Hockey League (NHL) concussions, part II: how concussions occur in the NHL.  

PubMed

BACKGROUND: Concussions in sports are a growing cause of concern, as these injuries can have debilitating short-term effects and little is known about the potential long-term consequences. This work aims to describe how concussions occur in the National Hockey League. METHODS: Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006-2010 seasons. Digital video records were coded and analysed using a standardised protocol. RESULTS: 88% (n=174/197) of concussions involved player-to-opponent contact. 16 diagnosed concussions were a result of fighting. Of the 158 concussions that involved player-to-opponent body contact, the most common mechanisms were direct contact to the head initiated by the shoulder 42% of the time (n=66/158), by the elbow 15% (n=24/158) and by gloves in 5% of cases (n=8/158). When the results of anatomical location are combined with initial contact, almost half of these events (n=74/158) were classified as direct contact to the lateral aspect of the head. CONCLUSIONS: The predominant mechanism of concussion was consistently characterised by player-to-opponent contact, typically directed to the head by the shoulder, elbow or gloves. Also, several important characteristics were apparent: (1) contact was often to the lateral aspect of the head; (2) the player who suffered a concussion was often not in possession of the puck and (3) no penalty was called on the play. PMID:23637116

Hutchison, Michael G; Comper, Paul; Meeuwisse, Willem H; Echemendia, Ruben J

2013-06-13

72

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

NASA Astrophysics Data System (ADS)

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

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

2006-07-01

73

Echocardiographic findings in professional hockey players  

PubMed Central

Tissue Doppler imaging was used to evaluate the physiological and morphological response in athletes whose cardiac system must not only adapt to intense cardiovascular demands but also support sudden, transient changes in cardiac output. A total of 45 professional hockey players with a mean age of 24 years underwent a baseline transthoracic echocardiographic protocol after a typical morning workout; 12 healthy age- and gender-matched controls were evaluated as a means of comparison. The athletes in this study possessed larger left ventricular diastolic and systolic dimensions than the control group (5.5 ± 0.4 vs 4.9 ± 0.4 cm and 3.9 ± 0.4 vs 3.3 ± 0.4 cm, P < 0.0001). The increase in athletes' septal and posterior wall thickness was not substantial, nor was there a significant difference in left ventricular ejection fraction. The athletes demonstrated consistently larger left ventricular end-diastolic volume (196 ± 34 vs 136 ± 23 mL, P < 0.001) and end-systolic volume (87 ± 20 vs 57 ± 12 mL, P < 0.0001). They also had lower annular septal and lateral early diastolic and systolic tissue Doppler velocities compared with the control group. Thus, characteristic myocardial changes previously reported in elite athletes were also represented in professional hockey players. The lower left ventricular tissue Doppler velocities was a relatively unique finding and probably a consequence of lower postexertion preload levels compared with controls who were measured at rest.

Fazel, Poorya; Roberts, Brad J.; Brooks, John

2009-01-01

74

Helminth communities of European eels Anguilla anguilla (Linnaeus, 1758) from the Vistula Lagoon and Puck Bay, Poland.  

PubMed

Within 2001-2002 a total of 621 eel Anguilla anguilla (L., 1758) (488 from the Vistula Lagoon and 133 from the Puck Bay) were examined. Fifteen parasite taxa were recovered: Pseudodactylogyrus anguillae (Yin et Sproston, 1948), Brachyphallus crenatus (Rudolphi, 1802), Deropristis inflata (Molin, 1859), Diplostomum spp., Bothriocephalus claviceps (Goeze, 1782), Proteocephalus macrocephalus (Creplin, 1825), Anguillicola crassus (Kuwahara, Niimi et Itagaki, 1974), Camallanus lacustris (Zoega, 1776), Cystidicola farionis Fischer, 1798, Hysterothylacium aduncum (Rudolphi, 1802), Raphidascaris acus (Bloch, 1779), Acanthocephalus anguillae (Müller, 1780), A. lucii (Müller, 1776), Echinorhynchus gadi Müller, 1776, and Pomphorhynchus laevis (Müller, 1776), representing Monogenea, Digenea, Cestoda, Nematoda, and Acanthocephala, respectively. Ten of these taxa occurred in the Vistula Lagoon, while fourteen were noted in the Puck Bay. P. anguillae, Diplostomum spp., C. lacustris, C. farionis and P. laevis were not found in the lagoon eels, while B. crenatus did not occur in the bay. Anguillicola crassus was the most frequently found parasite (Vistula Lagoon: prevalence 75%, mean intensity 6.9 specimens; Puck Bay: 74.4%, and 8.3 specimens, respectively). Pseudodactylogyrus anguillae was recorded for the first time in the Puck Bay. PMID:16838624

Bystydzie?iska, Zofia; Rolbiecki, Leszek; Rokicki, Jerzy

2005-01-01

75

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

National Technical Information Service (NTIS)

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 explo...

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

1981-01-01

76

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

SciTech Connect

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.

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

1981-05-01

77

FY04-Q4 REPORT: LX-17 MODELING  

SciTech Connect

TATB containing explosives tend to permanently expand as their temperatures are increased or thermally cycled, a phenomenon known as ''ratchet-growth.'' Mesoscale simulations using dissipative particle dynamics (DPD) have been carried out in order to study the geometric packing effects of TATB pressed powders under stress conditions. Further, our mesoscale simulations of polycrystalline TATB pressed powders have been used to predict hot-spot changes as a function of temperature (thermal cycling) and confinement. Our DPD simulations showed irreversible permanent growth in the mesoscale pressed powders only when crystal fracture induced by the anisotropic thermal expansion of TATB was incorporated into the model.

Gee, R; Fried, L

2004-11-30

78

'Zamboni disease'. Pulmonary edema in an ice hockey player.  

PubMed

A 17-year-old previously well ice hockey player experienced acute shortness of breath and cough productive of clear frothy sputum about 1.5 hours following an ice hockey match. Noncardiogenic pulmonary edema was found to develop as a result of the inhalation of the oxides of nitrogen. The latter was produced by a Zamboni machine that is used to resurface the ice on a rink. Several other players were affected but less severely. PMID:7503608

Morgan, W K

79

Personal food systems of male college hockey players.  

PubMed

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

Smart, L R; Bisogni, C A

2001-08-01

80

NBC Learn: Science of NHL Hockey  

NSDL National Science Digital Library

This is the portal for a collection of short videos that explore the science behind professional hockey. Funded by the National Science Foundation, the videos aim to provide engaging real-world examples of key concepts in physics: Newton's Laws, momentum and its conservation, conservation of energy, vectors, impulse and collision, and projectile motion. NHL players are featured in each video, with motion displayed in archived game clips and newly-created video captured with a super high-speed Phantom Cam. Physicists appear in each video to explain the concepts being demonstrated and clarify the connections to physics. Included are 20 lesson plans for middle school and high school, developed for use specifically with the videos.

2012-04-30

81

Injury Rates, Risk Factors, and Mechanisms of Injury in Minor Hockey  

Microsoft Academic Search

Background: Hockey is one of the top sports for participation in youth in Canada. There are limited data on the epidemiology of injury in youth hockey.Purpose: Through implementation and validation of an injury surveillance system, youth ice hockey injury rates, risk factors, and mechanisms of injury will be examined.Study Design: Descriptive epidemiology study.Methods: During the 2004-2005 season in minor hockey

Carolyn A. Emery; Willem H. Meeuwisse

2006-01-01

82

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

ERIC Educational Resources Information Center

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)

Woodcock, Amy Terhaar

1995-01-01

83

Description, Analysis and Prediction of Player Actions in Selected Hockey Game Situations  

Microsoft Academic Search

Abstract Motion is an important cue to the intentions of active agents in environments involving collaboration and competition. We demonstrate this in the domain of ice hockey. We develop a framework to represent and reason about hockey behaviors using as input actual player motion trajectory data tracked from game video and supported by knowledge of hockey strategy, game context and

Fahong Li

2004-01-01

84

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

ERIC Educational Resources Information Center

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,…

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

85

Injuries in Youth Hockey. On-Ice Emergency Care.  

ERIC Educational Resources Information Center

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…

Blanchard, Bradford M.; Castaldi, Cosmo R.

1991-01-01

86

Physiological profiles of representative women softball, hockey and netball players  

Microsoft Academic Search

Maximum aerobic and anaerobic power has been measured in 29 top class female athletes. The subjects were members of their respective South Australian representative teams for the 1977 season. The hockey players (N = 11) registered the highest mean treadmill [Vdot]0 max of 50-2 ml\\/kgmin which was significantly greater ( p < 0 05) than that of either the softballers

R. T. WITHERS; R. G. D. ROBERTS

1981-01-01

87

A Hockey Night in Canada: An Imagined Conversation between Theorists  

ERIC Educational Resources Information Center

In this paper, various methodological issues surrounding the sociological study of sport are explored. Through an imagined dialogue between two graduate students at a hockey game, this work brings together three divergent approaches to social enquiry: Positivist Grounded Theory, Constructivist Grounded Theory, and Actor-Network Theory. This paper…

Fogel, Curtis

2010-01-01

88

Athlete Violence and Aggression in Hockey and Interpersonal Relationships  

Microsoft Academic Search

Because male athletes have exhibited aggressive tendencies in a variety of settings, they may be at risk for using violence both within and beyond their sports involvement. Five former college\\/professional hockey players were interviewed to determine their perspec- tives on the nature of aggression and violence in sports competition as well as in social relationships. The informants were asked about

NICK T. PAPPAS; PATRICK C. MCKENRY

89

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

NASA Astrophysics Data System (ADS)

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 ??R?abl in plastic-ablator DT-filled capsules at OMEGA [2], by allowing ??R?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 ??R?abl.

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

90

Examination of birthplace and birthdate in world junior ice hockey players  

Microsoft Academic Search

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

Mark W. Bruner; Dany J. MacDonald; William Pickett; Jean Côté

2011-01-01

91

Rink-side management of ice hockey related injuries to the face, neck, and chest.  

PubMed

Ice hockey is a fast paced sport with unique injury potential. A covering physician must be prepared to acutely manage injuries to the face, neck, and chest that are not common in orthopedic practice. Injuries about the face seen in ice hockey include facial fractures, lacerations, and eye and dental injuries. Neck trauma can result in lacerations and neurologic injury. Commotio cordis and sudden cardiac death are potentially fatal conditions seen in ice hockey. This review details the appropriate acute management of these conditions for the physician covering an ice hockey game. Knowledge of these conditions and appropriate rink-side management can be potentially life-saving. PMID:24344616

Cohn, Randy M; Alaia, Michael J; Strauss, Eric J; Feldman, Andrew F

2013-01-01

92

Energy expenditure and physical fitness of ice-hockey players  

Microsoft Academic Search

Summary  We examined the energy expenditure in ice-hockey players under conditions of a model training match. The results were obtained in a group of 13 players of the national representative team (age 24.4 years), and in 1 goaler. In the players we also followed the physical fitness by means of a loading experiment on bicycle ergometer in the middle of the

V. Seliger; V. Kostka; D. Grušová; J. Ková?; J. Machovcová; M. Pauer; A. P?ibylová; R. Urbánková

1972-01-01

93

Sport selection in under-17 male roller hockey.  

PubMed

Characteristics of 32 international and 41 local under-17 (U-17) (14.5-16.5 years) roller hockey players were considered in the context of discrimination by competitive level using training history, anthropometry, skeletal maturation, and several laboratory and field performance tests. More international (42%) than local (22%) players were advanced in maturity status. International players had slightly less hockey experience (years), but had more practice sessions and match time (minutes) during the season. Local players were shorter and attained better performance in the 25-m dash, while international players performed better in sit-ups, ball throw and 20-m shuttle run. The fatigue index derived from the Wingate anaerobic test was higher among local players, while peak torques of knee extension and flexion were greater in international players. Stepwise discriminant function correctly classified 85% of players by competitive level based on grip strength, ratio of eccentric and concentric knee extension, number of training sessions, playing time and fatigue index. The results suggested an interaction among strength, anaerobic fitness and training plus game time as factors in discriminating international from local level players and by inference in the selection and development of youth roller hockey players. PMID:22867426

Coelho-E-Silva, Manuel J; Vaz, Vasco; Simões, Filipe; Carvalho, Humberto M; Valente-Dos-Santos, João; Figueiredo, António J; Pereira, Vanildo; Vaeyens, Roel; Philippaerts, Renaat; Elferink-Gemser, Marije T; Malina, Robert M

2012-12-01

94

In-Game Fatigue Influences Concussions in National Hockey League Players  

Microsoft Academic Search

The number of concussions and other head injuries are increasing in the National Hockey League (NHL). The factors that may influence concussion risk in hockey remain largely unknown. In the current study, data on 787 NHL players from the 2001–2002 season were examined. It was found that a player's average ice time per game was a significant predictor of concussion.

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

2008-01-01

95

THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY  

PubMed Central

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 190.7±7.2 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 111.0±8.8 L · min?1 and 70.3±14.0 L · min?1 (60% of VEmax), respectively. VO2max was 56.3±8.4 mL · kg?1 · min?1, and mean oxygen consumption was 40.9±7.9 mL · kg?1 · min?1 (70% of VO2max). Maximum blood lactate concentration was 7.2±1.3 mmol · L-1. ST yielded an energy expenditure of 899.1±232.9 kJ, and energy power was 59.9±15.5 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.

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

2013-01-01

96

Playing hockey, riding motorcycles, and the ethics of protection.  

PubMed

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

Bachynski, Kathleen E

2012-12-01

97

Static and dynamic postural control adaptations induced by playing ice hockey  

Microsoft Academic Search

In ice hockey, players produce high velocities by skating and game actions are typically characterized by sudden accelerations\\u000a and brisk decelerations. Thus, the vestibular system is particularly stressed. The aims of this study were to evaluate sensorial\\u000a organization and head stabilization control of ice hockey players in order to investigate if this kind of activity induces\\u000a specific sensorimotor adaptation. We

D. Alpini; A. Hahn; D. Riva

2008-01-01

98

NHL.com: The National Hockey League Web Site  

NSDL National Science Digital Library

The NHL's official site is a good place to start for anyone interested in the professional version of Canada's national pastime. Unfortunately, the site doesn't contain an archive of boxscores and/or recaps of all games. However, extensive boxes and recaps are provided for the latest games. Updated statistics are available on a wide variety of team and individual variables, and information is available on the various teams. But what really makes this site interesting are the "Cool Shots" section (8 multimedia highlights from the previous week's play--archived back to the beginning of the season), and "Feature Files," a potpourri of information including weekly reviews, instruction, and special features highlighted by "A Day in the Life of the National Hockey League," a photo essay of the NHL on March 23, 1996.

99

The Ice Hockey Injury An Interrupted Case Study  

NSDL National Science Digital Library

The high school ice hockey team is playing the last of three games in one day. The game gets rough and Rick, the star player, is slammed against the boards. Injured, he has to be  escorted from the ice. This interrupted case study follows Ricks health as it deteriorates over the next few hours. Students are presented with Rick’s symptoms and use their knowledge of anatomy and physiology to diagnose the problem. The case was developed for a one-semester animal physiology course taken mostly by sophomore and junior biology or general science majors. It could also be used in a freshman general biology course, anatomy and physiology course, or human physiology course for non-science majors.

Stephens, Phil

2004-01-01

100

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

ERIC Educational Resources Information Center

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

Blann, Wayne; Zaichkowsky, Leonard

101

Economic Impact of Youth Hockey Tournaments: A Case Study of the La Crosse and Onalaska Ice Rinks  

Microsoft Academic Search

Youth hockey is a major recreational and family event in Wisconsin and throughout the upper Midwest. Formal programs exist for youth simply interested in learning skating skills and the fundamentals of hockey to those interesting in competing in national and international tournaments. Demand for \\

Marc Schultz

2000-01-01

102

Neuropsychological factors related to college ice hockey concussions.  

PubMed

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

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

2014-05-01

103

Heart rate & blood lactate response in field hockey players.  

PubMed

The heart rate and blood lactate were studied in field hockey players (25 juniors and 29 seniors) as well as the blood lactate response in training to assess the anaerobic demand of the game and the adaptability of the players to anaerobic metabolism, respectively. The mean VO2 max of the junior and senior players were 3.32 l/min (54.4 ml/kg/min) and 3.28 l/min (53.8 ml/kg/min), respectively. Blood lactate levels after warm up, training and the game were 2.1, 7.4 and 4.2 mM/l, respectively for the juniors and 2.6, 7.7 and 5.6 mM/l, for the seniors. The aerobic capacity (VO2 max) of the juniors did not differ from their senior counterparts, indicating a similar adaptability to aerobic metabolism. However, the Indian players revealed a lower VO2 max than their International counterparts. Similar lactate levels in juniors and seniors after training indicated a similar adaptability to the anaerobic metabolism also. The higher blood lactate level in seniors after the game reflected that they played with greater intensity than the juniors, due to more experience, better motivation and skill. PMID:1794891

Ghosh, A K; Goswami, A; Mazumdar, P; Mathur, D N

1991-10-01

104

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

PubMed

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

Ransdell, Lynda B; Murray, Teena

2011-09-01

105

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

NASA Astrophysics Data System (ADS)

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

Choi, E.-Joon

2014-02-01

106

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

PubMed

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

Davidson, Judy

2009-01-01

107

Effect of bodychecking on rate of injuries among minor hockey players  

PubMed Central

Background Bodychecking is a leading cause of injury among minor hockey players. Its value has been the subject of heated debate since Hockey Canada introduced bodychecking for competitive players as young as 9 years in the 1998/1999 season. Our goal was to determine whether lowering the legal age of bodychecking from 11 to 9 years affected the numbers of all hockey-related injuries and of those specifically related to bodychecking among minor hockey players in Ontario. Methods In this retrospective study, we evaluated data collected through the Canadian Hospitals Injury Reporting and Prevention Program. The study’s participants were male hockey league players aged 6–17 years who visited the emergency departments of 5 hospitals in Ontario for hockey-related injuries during 10 hockey seasons (September 1994 to May 2004). Injuries were classified as bodychecking-related or non-bodychecking-related. Injuries that occurred after the rule change took effect were compared with those that occurred before the rule’s introduction. Results During the study period, a total of 8552 hockey-related injuries were reported, 4460 (52.2%) of which were attributable to bodychecking. The odds ratio (OR) of a visit to the emergency department because of a bodychecking-related injury increased after the rule change (OR 1.26, 95% confidence interval [CI] 1.16–1.38), the head and neck (OR 1.52, 95% CI 1.26–1.84) and the shoulder and arm (OR 1.18, 95% CI 1.04–1.35) being the body parts with the most substantial increases in injury rate. The OR of an emergency visit because of concussion increased significantly in the Atom division after the rule change, which allowed bodychecking in the Atom division. After the rule change, the odds of a bodychecking-related injury was significantly higher in the Atom division (OR 2.20, 95% CI 1.70–2.84). Interpretation In this study, the odds of injury increased with decreasing age of exposure to bodychecking. These findings add to the growing evidence that bodychecking holds greater risk than benefit for youth and support widespread calls to ban this practice.

Cusimano, Michael D; Taback, Nathan A; McFaull, Steven R; Hodgins, Ryan; Bekele, Tsegaye M; Elfeki, Nada

2011-01-01

108

Explosive Model Tarantula V1\\/JWL++ Calibration of LX17: #2  

Microsoft Academic Search

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

P C Souers; P Vitello

2009-01-01

109

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

SciTech Connect

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.

Souers, P C; Vitello, P

2009-05-01

110

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

Microsoft Academic Search

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

B. Levesque; E. Dewailly; R. Lavoie; D. PrudHomme; S. Allaire

1990-01-01

111

Women's Collective Identity Formation in SportsA Case Study from Women's Ice Hockey  

Microsoft Academic Search

This research examines the emergence and development of a women's collegiate ice hockey club at a large university in the midwestern United States during the 1990s. The aim of this article is to assess the role that collective action plays in contesting sexist structures and practices within a traditionally male-dominated institution. This article draws on collective identity theory, as articulated

CYNTHIA FABRIZIO PELAK

2002-01-01

112

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

ERIC Educational Resources Information Center

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…

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

2004-01-01

113

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

PubMed

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

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

2014-07-01

114

Teres major muscle tear in two professional ice hockey players: cases study and literature review.  

PubMed

Ice hockey is a sport renowned for its numerous injuries; different studies report between 13.8 and 20 lesions per 1000 athlete exposures. Exactly 65.5% of these injuries occur during games, compared to 34.5% during training sessions. And 35.1% of all injuries involve the lower extremity and 29.7% the upper extremity (results drawn from games and training combined). Determining whether muscle injuries are extrinsic (contusions) or intrinsic (tears) is of utmost importance since the former generally require simple follow-up, whereas the latter necessitates further investigations, appropriate treatment and often prolonged absence from sports for the injured athlete. To our knowledge, no publication to date has reported isolated damage of the teres major muscle in Ice Hockey players. Seven cases were reported amongst baseball pitchers. Two cases presented after a waterskiing traction accident and a further case has been described in a tennis player. In the present study, we report two cases of isolated teres major tear in ice hockey players. These two athletes were both professional players competing at the highest level in the Swiss Ice Hockey League. PMID:22197182

Grosclaude, M; Najihi, N; Lädermann, A; Menetrey, J; Ziltener, J-L

2012-02-01

115

Validation of the FAST skating protocol to predict aerobic power in ice hockey players.  

PubMed

Few studies have reported a sport-specific protocol to measure the aerobic power of ice hockey players using a predictive process. The purpose of our study was to validate an ice hockey aerobic field test on players of varying ages, abilities, and levels. The Faught Aerobic Skating Test (FAST) uses an on-ice continuous skating protocol on a course measuring 160 feet (48.8 m) using a CD to pace the skater with a beep signal to cross the starting line at each end of the course. The FAST incorporates the principle of increasing workload at measured time intervals during a continuous skating exercise. Step-wise multiple regression modelling was used to determine the estimate of aerobic power. Participants completed a maximal aerobic power test using a modified Bruce incremental treadmill protocol, as well as the on-ice FAST. Normative data were collected on 406 ice hockey players (291 males, 115 females) ranging in age from 9 to 25 y. A regression to predict maximum aerobic power was developed using body mass (kg), height (m), age (y), and maximum completed lengths of the FAST as the significant predictors of skating aerobic power (adjusted R2 = 0.387, SEE = 7.25 mL.kg-1.min-1, p < 0.0001). These results support the application of the FAST in estimating aerobic power among male and female competitive ice hockey players between the ages of 9 and 25 years. PMID:17622284

Petrella, Nicholas J; Montelpare, William J; Nystrom, Murray; Plyley, Michael; Faught, Brent E

2007-08-01

116

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

ERIC Educational Resources Information Center

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…

Forrest, Krista D.

2005-01-01

117

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

PubMed Central

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

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

2011-01-01

118

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

ERIC Educational Resources Information Center

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…

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

2014-01-01

119

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

PubMed Central

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.

Toy, Brian J.

1996-01-01

120

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

PubMed

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

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

2014-04-01

121

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

PubMed Central

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.

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

2013-01-01

122

Association between Short Sleeping Hours and Physical Activity in Boys Playing Ice Hockey  

Microsoft Academic Search

Objectives To determine physical activity in healthy boys and how physical activity relates to training and daily awake hours. Study design In 66 boys (5 to 15 years) affiliated with an ice-hockey club, we measured total daily energy expenditure (TDEE, doubly-labeled water) and basal metabolic rate (ventilated-hood method). Physical activity energy expenditure for the whole day (DAEE), during training, and

URS EIHOLZER; UDO MEINHARDT; VALENTIN ROUSSON; MICHAEL SCHLUMPF; GERHARD FUSCH; CHRISTOPH FUSCH; THEO GASSER; FELIX GUTZWILLER

123

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

PubMed Central

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.

Gomez, M.; Martin-Casado, L.; Navarro, E.

2012-01-01

124

Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.  

PubMed Central

OBJECTIVE--To determine the acute injury profile in each of six sports and compare the injury rates between the sports. DESIGN--Analysis of national sports injury insurance registry data. SETTING--Finland during 1987-91. SUBJECTS--621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. MAIN OUTCOME MEASURES--Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and their doctors. RESULTS--54,186 sports injuries were recorded. Injury rates were low in athletes aged under 15, while 20-24 year olds had the highest rates. Differences in injury rates between the sports were minor in this adult age group. Overall injury rates were higher in sports entailing more frequent and powerful body contact. Each sport had a specific injury profile. Fractures and dental injuries were most common in ice hockey and karate and least frequent in volleyball. Knee injuries were the most common cause of permanent disability. CONCLUSIONS--Based on the defined injury profiles in the different sports it is recommended that sports specific preventive measures should be employed to decrease the number of violent contacts between athletes, including improved game rules supported by careful refereeing. To prevent dental injuries the wearing of mouth guards should be encouraged, especially in ice hockey, karate, and basketball.

Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.

1995-01-01

125

Incidence and Injury Characteristics of Medial Collateral Ligament Injuries in Male Collegiate Ice Hockey Players  

PubMed Central

Background: Medial collateral ligament (MCL) injuries are the second most common injury resulting in player lost time in elite-level ice hockey. Purpose: To determine the incidence and injury characteristics of knee MCL sprain in male collegiate ice hockey players. Study Design: Case control. Methods: Athlete exposure data demographics, mechanism of injury, player position, time of injury occurrence (game vs practice), grade of MCL sprain, concomitant injuries, and lost time for cases were extracted from a computerized injury database of 8 college hockey seasons at 1 university. MCL injury rates were calculated. Injury characteristics were descriptively summarized. Simple linear regression was utilized to determine the relationship between the grade of MCL injury and player lost time. Results: There were 13 MCL injuries in 10 players. The overall incidence rate was 0.44 injuries per 1000 athlete exposures. Two players suffered reinjuries. Defensemen and forwards were equally represented. Contact with another player or the ice was the mechanism of injury in 77% of players. Grade 2 injuries were most common. The grade of injury predicted time lost from play (P < 0.01). Conclusion and Clinical Relevance: The lost time relates directly to the severity of injury.

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

2013-01-01

126

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

PubMed Central

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.

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

2014-01-01

127

Gastrointestinal temperature increases and hypohydration exists after collegiate men's ice hockey participation.  

PubMed

The cold environments in which ice hockey players participate are counterintuitive to the predisposing factors of heat- and hypohydration-related illnesses. This population has received little consideration in hypohydration-related illness risk assessments. Protective equipment, multiple clothing layers, and performance intensity may predispose these athletes to significant decreases in hydration and increases in core temperature. The purpose of this study was to measure hydration status and gastrointestinal temperature (T(GI)) in male ice hockey players during practice sessions that focused on pre-season skill development and cardiovascular conditioning. The study used a repeated measures design. Data were collected in a collegiate ice hockey rink (ambient temperature = 6.03 +/- 1.65 degrees C; relative humidity = 40.4 +/- 11.89%). Seventeen ice hockey players (age = 20.6 +/- 1.1, height = 180 +/- 5 cm, mass = 85.04 +/- 7.9 kg) volunteered for this study. Urine-specific gravity (USG) and body weight were measured before and after two 110-minute practice sessions. Urine reagent strips measured USG. Calibrated CorTemp (HQ, Inc., Palmetto, FL, USA) radiofrequency telemetered thermometers collected T(GI) before, during, and after two 110-minute practice sessions. Individual participant sweat rates were calculated. Data from both sessions were pooled. T(GI) (p < 0.0001), and USG (p < 0.0001) increased over the 110-minute session. Post-exercise body weight (83.9 +/- 7.6 kg) was statistically lower (p < 0.001) than the pre-exercise weight (85.0 +/- 7.9 kg). Sweat rates were calculated to be 0.83 +/- 0.50 L.h(-1). These male ice hockey players become hypohydrated during participation potentially predisposing them to dehydration-related illnesses. This change in hydration status resulted in a gastrointestinal temperature increase and significant weight loss during activity. Prevention and rehydration strategies such as those developed by the American College of Sports Medicine and National Athletic Trainers' Association should be implemented to reduce the possibility of heat-related illness for this population. PMID:20042926

Batchelder, Benson C; Krause, B Andrew; Seegmiller, Jeff G; Starkey, Chad A

2010-01-01

128

The Assessment of Airway Maneuvers and Interventions in University Canadian Football, Ice Hockey, and Soccer Players  

PubMed Central

Abstract Context: Managing an airway in an unconscious athlete is a lifesaving skill that may be made more difficult by the recent changes in protective equipment. Different airway maneuvers and techniques may be required to help ventilate an unconscious athlete who is wearing full protective equipment. Objective: To assess the effectiveness of different airway maneuvers with football, ice hockey, and soccer players wearing full protective equipment. Design: Crossover study. Setting: University sports medicine clinic. Patients or Other Participants: A total of 146 university varsity athletes, consisting of 62 football, 45 ice hockey, and 39 soccer players. Intervention(s): Athletes were assessed for different airway and physical characteristics. Three investigators then evaluated the effectiveness of different bag-valve-mask (BVM) ventilation techniques in supine athletes who were wearing protective equipment while inline cervical spine immobilization was maintained. Main Outcome Measure(s): The effectiveness of 1-person BVM ventilation (1-BVM), 2-person BVM ventilation (2-BVM), and inline immobilization and ventilation (IIV) was judged by each investigator for each athlete using a 4-point rating scale. Results: All forms of ventilation were least difficult in soccer players and most difficult in football players. When compared with 1-BVM, both 2-BVM and IIV were deemed more effective by all investigators for all athletes. Interference from the helmet and stabilizer were common reasons for difficult ventilation in football and ice hockey players. Conclusions: Sports medicine professionals should practice and be comfortable with different ventilation techniques for athletes wearing full equipment. The use of a new ventilation technique, termed inline immobilization and ventilation, may be beneficial, especially when the number of responders is limited.

Delaney, J. Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Troutman, Tracy; Aljufaili, Mahmood; Correa, Jose A.

2011-01-01

129

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

PubMed

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 (12°C; 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 ± 0.20°C vs. 34.46 ± 0.16°C) and core temperatures (37.50 ± 0.13°C vs. 37.59 ± 0.14°C) 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

Noonan, Benjamin; Stachenfeld, Nina

2012-09-01

130

Evaluation of cardiovascular demands of game play and practice in women's ice hockey.  

PubMed

Preparation for the physical demands of competition often involves game simulation during practice. This paradigm is thought to promote physiological adaptations that enhance maximal performance. However, a mismatch between practice intensity and actual competition intensity may not provide adequate training to achieve optimal game-play fitness. The purpose of this study was to evaluate the effectiveness of practice in meeting the cardiovascular demands of a women's ice hockey game. Heart rate (HR) data from 11 U.S. National Women's Ice Hockey team members were collected (5-second intervals) during a game and a typical practice session. Data was normalized to individual HRmax determined during Vo(2)max testing. Working time was defined as a game shift or practice-working interval. Mean working HR was greater during the game than the practice, 90 +/- 2% and 76 +/- 3% of HRmax, respectively (p < 0.05). Mean percent session time (game or practice) >90% HRmax was also longer during the game than the practice, 10.5 +/- 4.1% and 5.6 +/- 3.5% (p < 0.05), respectively. Mean session HR, percent time >80% HRmax, and mean resting HR were not different between game and practice (68 +/- 7% vs. 69 +/- 5%, 23.2 +/- 5.3% vs. 26.1 +/- 9.2%, and 59 +/- 8% vs. 56 +/- 5%, respectively). Elite women hockey players experience significantly greater cardiovascular load during game play than during practice. This mismatch in cardiovascular demand may prevent players from achieving "game shape," thus affecting competition play. PMID:12741872

Spiering, Barry A; Wilson, Meredith H; Judelson, Daniel A; Rundell, Kenneth W

2003-05-01

131

International field hockey players perform more high-speed running than national-level counterparts.  

PubMed

This study compared the activity profile of national and international male field hockey athletes. Sixteen players (mean (±SD) age, stature, and body mass: 22 ± 4 y, 178 ± 8 cm, and 78 ± 9 kg, respectively) competing in the national-level Australian Hockey League (AHL) and 16 players [mean (±SD) age, stature, and body mass: 27 ± 4 y, 179 ± 5 cm, and 77 ± 5 kg, respectively] competing in the international Champions Trophy (CT) tournament participated in this study. Global positioning systems assessed total distance (TD), meters per minute (m·min(-1)), and high-speed running distance (HSR; >4.17 m·s(-1)). Differences in multistage fitness test performance, movement between competition, positions, and halves were assessed using effect size and percent difference ±90% confidence intervals. The CT players had a 10.1% greater multistage fitness test, 13.9% and 42.0% more TD and HSR, respectively, than AHL. During CT, strikers performed 10.1 ± 7.4% less HSR than midfielders and 26.6 ± 8.2% more HSR than defenders. The AHL defenders covered less TD and HSR distance compared with strikers and midfielders (8.1 ± 3.6% and 8.4 ± 2.6%; 36.1 ± 11.1% and 51.5 ± 12.1%, respectively). The AHL strikers, midfielders, and defenders (19.9 ± 8.8%, 32.1 ± 7.9%, and 30.3 ± 10.7%, respectively), all performed less HSR distance than their CT counterparts. Finally, TD decreased from the first to second halves across all positions (6.1-7.5%) in both competitions. International competition increases the running profile of hockey players, with greater HSR at the elite level and positional differences including decreased running during the second half in both competitions. PMID:22446668

Jennings, Denise H; Cormack, Stuart J; Coutts, Aaron J; Aughey, Robert J

2012-04-01

132

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

PubMed

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

Schwab, Sebastian; Memmert, Daniel

2012-01-01

133

The development and reliability of a repeated anaerobic cycling test in female ice hockey players.  

PubMed

The purpose of this study was to develop and assess the reliability of a repeated anaerobic power cycling test designed to mimic the repeated sprinting nature of the sport of ice hockey. Nineteen female varsity ice hockey players (mean X +/- SD age, height and body mass = 21 +/- 2 yr, 166.6 +/- 6.3 cm and 62.3 +/- 7.3) completed 3 trials of a repeated anaerobic power test on a Monark cycle ergometer on different days. The test consisted of "all-out" cycling for 5 seconds separated by 10 seconds of low-intensity cycling, repeated 4 times. The relative load factor used for the resistance setting was equal to 0.095 kg per kilogram body mass. There was no significant difference between the peak 5-second power output (PO), mean PO, or the fatigue index (%) among the 3 different trials. The peak 5-second PO was 702.6 +/- 114.8 w and 11.3 +/- 1.1 w x kg, whereas the mean PO across the 4 repeats was 647.1 +/- 96.3 w and 10.4 +/- 1.0 w x kg averaged for the 3 different tests. The fatigue index averaged 17.8 +/- 6.5%. The intraclass correlation coefficient for peak 5-second, mean PO, and fatigue index was 0.82, 0.86, and 0.82, respectively. This study reports the methodology of a repeated anaerobic power cycling test that was reliable for the measurement of PO and calculated fatigue index in varsity women ice hockey players and can be used as a laboratory-based assessment of repeated anaerobic fitness. PMID:20072039

Wilson, Kier; Snydmiller, Gary; Game, Alex; Quinney, Art; Bell, Gordon

2010-02-01

134

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

PubMed Central

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.

2006-01-01

135

An experiment to evaluate carbon monoxide absorption by hockey players in ice skating rinks.  

PubMed

Carbon monoxide (CO) released from the exhaust of ice resurfacing machinery is frequently found in indoor ice skating rinks. We conducted a study with 14 male adult non-smokers unexposed occupationally, who played hockey games in 4 different atmospheric CO concentrations. To document absorption, we measured their alveolar CO (alvCO). Exposure was the average CO level in the rink during the game. Environmental concentrations were between 0.0 (undetected) and 76.2 parts per million (ppm). The exposure-absorption relationship was linear (regression parameters: r2 = 0.93, slope = 0.411, intercept = -1.45). This means that for each 10 ppm of CO in the indoor air, the players absorbed enough CO to raise their alvCO by 4.1 ppm (approximately 0.76% carboxyhemoglobin). Taking into account the duration of the games, the regression coefficients were almost similar to those of an earlier study we made with 122 adult male hockey players playing in recreational leagues of the Quebec city area. These results show the exposure-absorption relationship for an acute 60-minute exposure, in a design which eliminated certain of the uncontrolled variables of our first study. It also emphasizes the importance of prevention for CO pollution in indoor skating rinks. PMID:2017867

Levesque, B; Lavoie, R; Dewailly, E; Prud'homme, D; Allaire, S

1991-02-01

136

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

PubMed Central

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.

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

1990-01-01

137

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

PubMed

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

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

1990-05-01

138

Aneurysmal Bone Cyst in a Female Collegiate Field Hockey Player: A Case Report  

PubMed Central

Objective: To present the case of an intercollegiate field hockey player with an aneurysmal bone cyst of the femur and the clinical decision making necessary in the evaluation, management, surgical intervention, and positive outcome of this athlete. Background: A 21-year-old field hockey player presented with signs and symptoms typical of a deep thigh contusion. She had no history of direct or indirect trauma, infection, or previous injury. Differential Diagnosis: Aneurysm, bone cyst, chondroma, giant cell tumor, osteochondroma, osteosarcoma, osteoid osteoma. Treatment: When her symptoms persisted beyond 6 months despite conservative care, she underwent radiographs, magnetic resonance imaging, and bone scan, which revealed a lesion in the right femur. At surgery, the lesion was diagnosed as an aneurysmal bone cyst, and it was excised by an incisional x-ray-guided biopsy followed by curettage and bone grafting. Uniqueness: The aneurysmal bone cyst presented as a typical thigh strain or deep contusion during the athlete's training and conditioning season. After all forms of conservative management proved ineffective, the athlete was referred to her physician. A detailed history and physical examination demonstrated no underlying musculoskeletal pathology coinciding with the athlete's symptoms. Conclusions: Increased clinical awareness is necessary when conservative management fails to resolve an athletic injury in an appropriate length of time. Proper diagnostic tools are essential in determining the pathology of the injury and whether surgical intervention is needed. ImagesFigure 1.Figure 2.Figure 3.

Berry, David C.; Barton, Julie; Deivert, Richard G.

2000-01-01

139

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

PubMed

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

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

2014-01-01

140

Bone mineral density and body composition of the United States Olympic women's field hockey team  

PubMed Central

OBJECTIVE: To evaluate total bone mineral density (BMD) and body composition (% fat) in world class women field hockey players, members of the 1996 United States Olympic team. METHODS: Whole body BMD (g/cm2) and relative body fatness (% fat) were assessed by dual energy x ray absorptiometry using a Lunar DPX-L unit with software version 1.3z. Body composition was also estimated by hydrostatic weighing and the sum of seven skinfolds. Results: Mean (SD) BMD was 1.253 (0.048) g/cm2 which is 113.2 (4.0)% of age and weight adjusted norms. Estimates of body composition from the three methods were similar (statistically non- significant): 16.1 (4.4)% fat from dual energy x ray absorptiometry, 17.6 (3.2)% from hydrostatic weighing, and 16.9 (2.6)% from the sum of seven skinfolds. Mean fat free mass was approximately 50 kg. CONCLUSIONS: The mean whole body BMD value for members of the 1996 United States Olympic women's field hockey team is one of the highest reported for any women's sports team. Moreover, the mean fat free mass per unit height was quite high and % fat was low. In this group of world class sportswomen, low % fat was not associated with low BMD. ?????

Sparling, P. B.; Snow, T. K.; Rosskopf, L. B.; O'Donnell, E. M.; Freedson, P. S.; Byrnes, W. C.

1998-01-01

141

Body dissatisfaction and drive for thinness in high performance field hockey athletes.  

PubMed

The prevalence of eating disordered tendencies and its relationship to body composition was examined in elite female field hockey players. Eating Disorder Inventory (EDI) and body composition (skinfold) data were collected from 111 (92.5%) athletes from 12 teams at the 1994 Indoor Canadian National Tournament. Athletes at risk for developing frank eating disorders were identified using cutoff scores of clinically diagnosed patients with eating disorders. 19/111 (17.1%) demonstrated increased body dissatisfaction (BD), and 4/111 (3.6%) an elevated drive for thinness, suggesting that concern for body shape and size is a greater issue in field hockey than preoccupation with weight. Compared to athletes not at risk, those with elevated BD scores were significantly heavier, fatter, and had higher BMIs. Although it appears that these athletes may have reason to be dissatisfied, they may be at increased risk for initiating and sustaining weight controlling behaviours associated with eating disorders. Special care must be taken in any intervention strategy. PMID:8912071

Marshall, J D; Harber, V J

1996-10-01

142

Traumatic upper limb injuries during the Men's Field Hockey Junior World Cup 2009.  

PubMed

This study was a prospective epidemiological investigation of upper limb injuries during the Men's Field Hockey Junior World Cup 2009. Three hundred twenty-four players were observed in 58 matches of the tournament. Twenty-eight upper limb-related injuries were documented. The injury incidence was 0.48 per match and 19 per 1,000 match hours. Most injuries were due to contact with the ball, and the left hand was the most commonly injured part. Contusion was the most common type of injury. The odds ratio for hand and wrist injuries in players not wearing gloves was 4.01 (95% CI, 0.52-30.62), and the relative risk of hand and wrist injuries in players wearing gloves was 0.26 (95% CI, 0.03-1.92). Male youth hockey players are at a high risk of upper limb, especially hand and wrist, injuries during major international tournaments and that use of protective gloves can provide significant protection against hand and wrist injuries in the sport. PMID:24067118

Mukherjee, Swarup

2013-01-01

143

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

SciTech Connect

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.

Levesque, B.; Dewailly, E.; Lavoie, R.; Prud'Homme, D.; Allaire, S. (Centre hospitalier de l'Universite Laval, Quebec City (Canada))

1990-05-01

144

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

ERIC Educational Resources Information Center

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)

Simard, Clermont; And Others

1988-01-01

145

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

PubMed

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

Tervo, Taru; Nordström, Peter; Nordström, Anna

2010-09-01

146

Physlet Force Concept Inventory: Collision and Speeds  

NSDL National Science Digital Library

The animations depict a hockey puck sliding with constant speed v0 in a straight line from point "a" to point "b" on a frictionless horizontal surface. Forces exerted by the air are negligible. When the puck reaches point "b", it receives a swift horizontal kick in the direction of the black arrow. Had the puck been at rest at point "b", then the kick would have sent the puck in horizontal motion with a speed vk in the direction of the kick.

Christian, Wolfgang; Belloni, Mario

2006-01-13

147

Physlet Force Concept Inventory: Collision  

NSDL National Science Digital Library

The animations depict a hockey puck sliding with constant speed v0 in a straight line from point "a" to point "b" on a frictionless horizontal surface. Forces exerted by the air are negligible. When the puck reaches point "b", it receives a swift horizontal kick in the direction of the black arrow. Had the puck been at rest at point "b", then the kick would have sent the puck in horizontal motion with a speed vk in the direction of the kick.

Christian, Wolfgang; Belloni, Mario

2006-01-13

148

Physlet Force Concept Inventory: Collison and Gravity  

NSDL National Science Digital Library

The animations depict a hockey puck sliding with constant speed v0 in a straight line from point "a" to point "b" on a frictionless horizontal surface. Forces exerted by the air are negligible. When the puck reaches point "b", it receives a swift horizontal kick in the direction of the black arrow. Had the puck been at rest at point "b", then the kick would have sent the puck in horizontal motion with a speed vk in the direction of the kick.

Christian, Wolfgang; Belloni, Mario

2006-01-13

149

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

PubMed Central

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)

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

2014-01-01

150

Discriminant effectiveness of psychological state measures in predicting selection during field hockey trials.  

PubMed

Field hockey players (N = 128) completed the Competitive State Anxiety Inventory-2 and the Profile of Mood States about 45 min. before a British Universities trial. Single-factor multivariate analysis of variance indicated no significant differences between selected and nonselected players for any preperformance mood or anxiety measure. Discriminant function analysis showed that 74 participants (57.81%) could be correctly classified as selected or nonselected players on the basis of preperformance mood scores. This figure rose to 83 participants (64.84%) when scores on the anxiety subscales were also included in the discriminant function analysis. Anxiety scores alone discriminated 71 participants (55.47%). These results concur with earlier proposals of Terry that psychological state measures decline in predictive effectiveness in long duration, open skill team sports. PMID:8724905

Terry, P C; Youngs, E L

1996-04-01

151

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

PubMed

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

Slater, M R; Sewell, D F

1994-10-01

152

In situ removal of the ``hockey stick`` fissile material deposit at the East Tennessee Technology Park  

SciTech Connect

Prior to shutdown of the gaseous diffusion process at the Oak Ridge K-25 Plant (now East Tennessee Technology Park), leakage of humid air into the process piping and equipment caused reactions with UF{sub 6}, which produced nonvolatile uranyl fluoride (UO{sub 2}F{sub 2}) deposition and other solid uranium fluoride compounds. During the period 1988--1991, Lockheed Martin Energy Systems performed nondestructive analysis (NDA) radiological surveys of the K-25 Site process facilities that previously had contained or processed uranium. These surveys were made to estimate the mass and {sup 235}U assay of localized uranium deposits remaining within the process piping and equipment. Three deposits were identified that had sufficient mass to achieve criticality. Two of these, the horizontal pipe and the T pipe deposits, required the addition of a moderator before a criticality accident could occur. The third was a very large uranium deposit determined by NDA to be distributed annularly in the process piping. Because of the shape of the system, it came to be called the hockey stick deposit. Because of the foregoing concerns with the hockey stick deposit, it was decided to gain experience by removing the less hazardous smaller deposits with their less complicated geometries first. Thus, the horizontal pipe deposit, the simplest and least reactive case, was handled first, in June 1997. Next, the T pipe, which was an intersection of large-diameter pipes and which posed additional problems because of a more complex geometry, was handled in August 1997. From this experience, the deposit removal techniques and procedures were refined. In December 1997, this large deposit was removed, and the contents were placed in a safe array configuration.

Lewis, K.D.; Tollefson, D.A. [Lockheed Martin Energy Systems (United States)

1998-12-31

153

The measurement of bound and free moisture in organic materials by microwave methods. [Explosives TATB and LX-17  

SciTech Connect

Bound and free moisture can be classified by energetic, structural, or operational schemes. We discuss these schemes and consider four methods (dynamic dielectric thermal analysis, microwave attenuation analysis, near-infrared reflectance analysis (NIRA) and nuclear magnetic resonance (NMR) spectroscopy) that have been suggested for distinguishing between bound and free moisture in organic materials. This report describes the microwave attenuation method. The theoretical basis for using microwaves for this purpose is developed. We show that microwave measurements can be used to measure the moisture in triaminotrinitrobenzene (TATB) using a microwave network analyzer down to 0.04% H/sub 2/O. The design of the apparatus necessary to extend these measurements to lower moisture content limits is mentioned. As part of this study, we measured the dielectric properties of TATB for the first time. We found that the dielectric constant epsilon' for TATB was 4.00 +- 0.01.

Pyper, J.W.; Buettner, H.M.; Cerjan, C.J.; Hallam, J.S.; King, R.J.

1984-11-01

154

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

PubMed

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

Rundell, Kenneth W

2004-03-01

155

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

PubMed Central

Background In 1997, the National Hockey League (NHL) and NHL Players’ Association (NHLPA) launched a concussion program to improve the understanding of this injury. We explored initial postconcussion signs, symptoms, physical examination findings and time loss (i.e., time between the injury and medical clearance by the physician to return to competitive play), experienced by male professional ice-hockey players, and assessed the utility of initial postconcussion clinical manifestations in predicting time loss among hockey players. Methods We conducted a prospective case series of concussions over seven NHL regular seasons (1997–2004) using an inclusive cohort of players. The primary outcome was concussion and the secondary outcome was time loss. NHL team physicians documented post-concussion clinical manifestations and recorded the date when a player was medically cleared to return to play. Results Team physicians reported 559 concussions during regular season games. The estimated incidence was 1.8 concussions per 1000 player-hours. The most common postconcussion symptom was headache (71%). On average, time loss (in days) increased 2.25 times (95% confidence interval [CI] 1.41–3.62) for every subsequent (i.e., recurrent) concussion sustained during the study period. Controlling for age and position, significant predictors of time loss were postconcussion headache (p < 0.001), low energy or fatigue (p = 0.01), amnesia (p = 0.02) and abnormal neurologic examination (p = 0.01). Using a previously suggested time loss cut-point of 10 days, headache (odds ratio [OR] 2.17, 95% CI 1.33–3.54) and low energy or fatigue (OR 1.72, 95% CI 1.04–2.85) were significant predictors of time loss of more than 10 days. Interpretation Postconcussion headache, low energy or fatigue, amnesia and abnormal neurologic examination were significant predictors of time loss among professional hockey players.

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

2011-01-01

156

Biomechanical analysis of the penalty-corner drag-flick of elite male and female hockey players  

Microsoft Academic Search

The aim of this study was to analyse the kinematic sequencing in the penalty-corner drag-flicks of elite male and female field hockey players of international calibre. Thirteen participants (one skilled male drag-flicker and six male and six female elite players) participated in the study. An optoelectronic motion analysis system was used to capture the drag-flicks with six cameras, sampling at

Cristina López De Subijana; Daniel Juárez; Javier Mallo; Enrique Navarro

2010-01-01

157

A systematic video analysis of National Hockey League (NHL) concussions, part I: who, when, where and what?  

PubMed

BACKGROUND: Although there is a growing understanding of the consequences of concussions in hockey, very little is known about the precipitating factors associated with this type of injury. AIM: To describe player characteristics and situational factors associated with concussions in the National Hockey League (NHL). METHODS: Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006-2010 seasons using an inclusive cohort of professional hockey players. Digital video records were coded and analysed using the Heads Up Checklist. RESULTS: Of 197 medically diagnosed concussions, 88% involved contact with an opponent. Forwards accounted for more concussions than expected compared with on-ice proportional representation (95% CI 60 to 73; p=0.04). Significantly more concussions occurred in the first period (47%) compared with the second and third periods (p=0.047), with the majority of concussions occurring in the defensive zone (45%). Approximately 47% of the concussions occurred in open ice, 53% occurred in the perimeter. Finally, 37% of the concussions involved injured players' heads contacting the boards or glass. CONCLUSIONS: This study describes several specific factors associated with concussions in the NHL, including period of the game, player position, body size, and specific locations on the ice and particular situations based on a player's position. PMID:23766438

Hutchison, Michael G; Comper, Paul; Meeuwisse, Willem H; Echemendia, Ruben J

2013-06-13

158

Do hockey players need aerobic fitness? Relation between VO2max and fatigue during high-intensity intermittent ice skating.  

PubMed

The primary objective of this study was to assess the relationship between aerobic capacity, as measured by the VO(2)max test, and recovery from high-intensity intermittent exercise. Eleven female collegiate hockey players agreed to participate. Subjects skated 5 1-lap intervals around the hockey rink at maximal intensity with a 30-second recovery period between skates. The VO(2)max test was performed on a motor-driven treadmill after a modified Bruce protocol. A fatigue index was calculated by measuring the total increase in skate time from trial 1 to trial 5. This fatigue index was then correlated to VO(2)max. This correlation coefficient (-0.422) was not significant (p > 0.05) and indicated that only 17.8% of the variance in VO(2)max could be explained by the fatigue index. It was concluded that ability to recover from high-intensity intermittent exercise is not related to aerobic capacity. Coaches and trainers probably do not need to include aerobic training in their practices, because the high-intensity interval training commonly seen in hockey training also improves aerobic capacity, as reflected in the high VO(2)max values of these subjects. PMID:17685680

Carey, Daniel G; Drake, Melanie M; Pliego, German J; Raymond, Robert L

2007-08-01

159

In your face: facial metrics predict aggressive behaviour in the laboratory and in varsity and professional hockey players  

PubMed Central

Facial characteristics are an important basis for judgements about gender, emotion, personality, motivational states and behavioural dispositions. Based on a recent finding of a sexual dimorphism in facial metrics that is independent of body size, we conducted three studies to examine the extent to which individual differences in the facial width-to-height ratio were associated with trait dominance (using a questionnaire) and aggression during a behavioural task and in a naturalistic setting (varsity and professional ice hockey). In study 1, men had a larger facial width-to-height ratio, higher scores of trait dominance, and were more reactively aggressive compared with women. Individual differences in the facial width-to-height ratio predicted reactive aggression in men, but not in women (predicted 15% of variance). In studies 2 (male varsity hockey players) and 3 (male professional hockey players), individual differences in the facial width-to-height ratio were positively related to aggressive behaviour as measured by the number of penalty minutes per game obtained over a season (predicted 29 and 9% of the variance, respectively). Together, these findings suggest that the sexually dimorphic facial width-to-height ratio may be an ‘honest signal’ of propensity for aggressive behaviour.

Carre, Justin M; McCormick, Cheryl M

2008-01-01

160

In your face: facial metrics predict aggressive behaviour in the laboratory and in varsity and professional hockey players.  

PubMed

Facial characteristics are an important basis for judgements about gender, emotion, personality, motivational states and behavioural dispositions. Based on a recent finding of a sexual dimorphism in facial metrics that is independent of body size, we conducted three studies to examine the extent to which individual differences in the facial width-to-height ratio were associated with trait dominance (using a questionnaire) and aggression during a behavioural task and in a naturalistic setting (varsity and professional ice hockey). In study 1, men had a larger facial width-to-height ratio, higher scores of trait dominance, and were more reactively aggressive compared with women. Individual differences in the facial width-to-height ratio predicted reactive aggression in men, but not in women (predicted 15% of variance). In studies 2 (male varsity hockey players) and 3 (male professional hockey players), individual differences in the facial width-to-height ratio were positively related to aggressive behaviour as measured by the number of penalty minutes per game obtained over a season (predicted 29 and 9% of the variance, respectively). Together, these findings suggest that the sexually dimorphic facial width-to-height ratio may be an 'honest signal' of propensity for aggressive behaviour. PMID:18713717

Carré, Justin M; McCormick, Cheryl M

2008-11-22

161

Factors influencing visor use among players in the National Hockey League (NHL).  

PubMed

Eye, orbital, and facial injuries are significant risks to National Hockey League (NHL) players, and can be mitigated by the use of a partial visor - currently optional for all non-rookie players. The goal of the current study was to determine the overall use of visors among non-rookie NHL players in the 2013-2014 season and assess factors influencing their uptake. This was an observational, cross-sectional study using active NHL rosters and demographic information obtained from the official NHL website. Visor use was determined based on in-game video or images at two different time points in the 2013-2014 season. The use of visors during the 2013-2014 season was 75.2% among non-rookie players. When rookies were included, the overall use of visors was 77.8%. Compared to Canadian-born players, European players were significantly more likely to choose to wear a visor (odds ratio [OR] 3.48, 95% confidence interval [CI] 1.96-6.17). Players in the younger age-groups, particularly those younger than 24 years (OR 5.67, 95% CI 2.52-5.76) and those between 24 and 28 years (OR 2.18, 95% CI 1.23-3.87), were more likely to wear a visor compared to older players. Overall, visor use continues to grow in the NHL independently of new legislation, and is more likely in younger players and those of European origin. PMID:24744613

Micieli, Robert; Micieli, Jonathan A

2014-01-01

162

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

PubMed

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

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

2014-01-01

163

Multidimensional performance characteristics and standard of performance in talented youth field hockey players: a longitudinal study.  

PubMed

To identify performance characteristics that could help predict future elite field hockey players, we measured the anthropometric, physiological, technical, tactical, and psychological characteristics of 30 elite and 35 sub-elite youth players at the end of three consecutive seasons. The mean age of the players at the end of the first season was 14.2 years (s = 1.1). Repeated-measures analyses of covariance, with standard of performance and measurement occasion as factors and age as a covariate, showed that the elite players fared better than the sub-elite players on technical and tactical variables. Female elite youth players also scored better on interval endurance capacity, motivation, and confidence. Future elite players appear to have excellent tactical skills by the age of 14. They also have good specific technical skills and develop these together with interval endurance capacity better than sub-elite youth players in the subsequent 2 years. To verify our conclusions, we will be tracking these players into adulthood. PMID:17365535

Elferink-Gemser, Marije T; Visscher, Chris; Lemmink, Koen A P M; Mulder, Theo

2007-02-15

164

Relation between multidimensional performance characteristics and level of performance in talented youth field hockey players.  

PubMed

To determine the relationship between multidimensional performance characteristics and level of performance in talented youth field hockey players, elite youth players (n = 38, mean age 13.2 years, s = 1.26) were compared with sub-elite youth players (n = 88, mean age 14.2 years, s = 1.26) on anthropometric, physiological, technical, tactical and psychological characteristics. Multivariate analyses with performance level and gender as factors, and age as the covariate, showed that the elite youth players scored better than the sub-elite youth players on technical (dribble performance in a peak and repeated shuttle run), tactical (general tactics; tactics for possession and non-possession of the ball) and psychological variables (motivation) (P < 0.05). The most discriminating variables were tactics for possession of the ball, motivation and performance in a slalom dribble. Age discriminated between the two groups, indicating that the elite youth players were younger than the sub-elite players. In the guidance of young talented players to the top as well as in the detection of talented players, more attention has to be paid to tactical qualities, motivation and specific technical skills. PMID:15801499

Elferink-Gemser, Marije T; Visscher, Chris; Lemmink, Koen A P M; Mulder, Theo W

2004-01-01

165

Why Do Sleeping Nematodes Adopt a Hockey-Stick-Like Posture?  

PubMed Central

A characteristic posture is considered one of the behavioral hallmarks of sleep, and typically includes functional features such as support for the limbs and shielding of sensory organs. The nematode C. elegans exhibits a sleep-like state during a stage termed lethargus, which precedes ecdysis at the transition between larval stages. A hockey-stick-like posture is commonly observed during lethargus. What might its function be? It was previously noted that during lethargus, C. elegans nematodes abruptly rotate about their longitudinal axis. Plausibly, these “flips” facilitate ecdysis by assisting the disassociation of the old cuticle from the new one. We found that body-posture during lethargus was established using a stereotypical motor program and that body bends during lethargus quiescence were actively maintained. Moreover, flips occurred almost exclusively when the animals exhibited a single body bend, preferentially in the anterior or mid section of the body. We describe a simple biomechanical model that imposes the observed lengths of the longitudinally directed body-wall muscles on an otherwise passive elastic rod. We show that this minimal model is sufficient for generating a rotation about the anterior-posterior body axis. Our analysis suggests that posture during lethargus quiescence may serve a developmental role in facilitating flips and that the control of body wall muscles in anterior and posterior body regions are distinct.

Tramm, Nora; Oppenheimer, Naomi; Nagy, Stanislav

2014-01-01

166

Factors influencing visor use among players in the National Hockey League (NHL)  

PubMed Central

Eye, orbital, and facial injuries are significant risks to National Hockey League (NHL) players, and can be mitigated by the use of a partial visor – currently optional for all non-rookie players. The goal of the current study was to determine the overall use of visors among non-rookie NHL players in the 2013–2014 season and assess factors influencing their uptake. This was an observational, cross-sectional study using active NHL rosters and demographic information obtained from the official NHL website. Visor use was determined based on in-game video or images at two different time points in the 2013–2014 season. The use of visors during the 2013–2014 season was 75.2% among non-rookie players. When rookies were included, the overall use of visors was 77.8%. Compared to Canadian-born players, European players were significantly more likely to choose to wear a visor (odds ratio [OR] 3.48, 95% confidence interval [CI] 1.96–6.17). Players in the younger age-groups, particularly those younger than 24 years (OR 5.67, 95% CI 2.52–5.76) and those between 24 and 28 years (OR 2.18, 95% CI 1.23–3.87), were more likely to wear a visor compared to older players. Overall, visor use continues to grow in the NHL independently of new legislation, and is more likely in younger players and those of European origin.

Micieli, Robert; Micieli, Jonathan A

2014-01-01

167

Baseline evaluation in youth ice hockey players: comparing methods for documenting prior concussions and attention or learning disorders.  

PubMed

Study Design Cross-sectional. Objective To examine differences in concussion history and attention or learning disorders reported by elite youth ice hockey players, using a questionnaire that allows parental input compared to a clinic-based test battery that does not. Background A history of previous concussion and the presence of attention or learning disorders can affect concussion-management decisions; however, youth athletes may not accurately report their medical history because they may not know or recall important details. Methods The sample included 714 Bantam (ages 12-14 years) and Midget (ages 15-17 years) ice hockey players (601 male, 113 female) from the most elite divisions of play (AA and AAA). Players completed a take-home preseason questionnaire (PSQ) with the input of a parent/guardian, and also independently completed the baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) at the beginning of the 2011-2012 hockey season. Results In 21.1% (95% confidence interval: 18.1%, 24.1%) of cases, there was disagreement between the PSQ and ImPACT in the number of previous concussions reported. Among those who reported an attention disorder on the PSQ, 85.7% also reported an attention disorder on the ImPACT. Only 9.5% of those who reported a learning disorder on the PSQ also reported a learning disorder on the ImPACT. Conclusion In 1 of 5 players, reported concussion history differed between the PSQ and ImPACT, and there was substantial disagreement between instruments for those reporting learning disorders. The method of obtaining medical history may, therefore, affect baseline and postconcussion evaluations. J Orthop Sports Phys Ther 2014;44(5):329-335. Epub 27 March 2014. doi:10.2519/jospt.2014.5053. PMID:24673445

McKay, Carly D; Schneider, Kathryn J; Brooks, Brian L; Mrazik, Martin; Emery, Carolyn A

2014-05-01

168

Paradigms in Physics: Central Forces on an Airtable  

NSDL National Science Digital Library

This student activity is designed to help upper division undergraduate students work with central forces in classical mechanics. A hockey puck is tethered to the center of an air-hockey table, and the students observe the motion of the hockey puck, allowing them to observe the effects of central forces on the puck. Students are asked to plot the potential energy graph of the hockey puck. An instructor's guide is available to help guide the activity along with the student handout. This material is part of the Paradigms in Physics project at Oregon State University. This work promotes the use of active student learning in upper division physics courses. Both learning materials and learning strategies are provided to help both students and instructors.

2013-02-21

169

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

PubMed

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

Boardley, Ian D; Kavussanu, Maria

2009-06-01

170

Three-dimensional kinematics of the knee and ankle joints for three consecutive push-offs during ice hockey skating starts  

Microsoft Academic Search

Little biomechanical research has been conducted recently on hockey skating despite the sport's worldwide appeal. One reason for this lack of biomechanical knowledge stems from the difficulty of collecting data. The lack of accuracy, the disputable realism of treadmills, and the large field of view required are some of the technical challenges that have to be overcome. The main objective

Dany Lafontaine

2007-01-01

171

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

PubMed

Research in many sports suggests that losing ~2% of body mass (BM) through sweating impairs athletic performance, although this has not been tested in ice hockey players. This study investigated pregame hydration, and on-ice sweat loss, fluid intake, and sodium (Na+) balance of elite male junior players during an ice hockey game. Twenty-four players (2 goalies, 7 defensemen, 15 forwards) volunteered to participate in the study (age, 18.3 ± 0.3 years; weight, 86.5 ±1.6 kg; height, 184.1 ± 1.3 cm). Players were weighed pre- and postgame, fluid and sodium intake were monitored throughout the game, and fluid and Na+ balance were determined within the time between BM measurements. Sweat Na+ loss was calculated based on sweat loss and sweat [Na+] determined from sweat-patch analysis on the same players during an intense practice. Players arrived at the rink in a euhydrated state and drank 0.6 ± 0.1 L of fluid before the game. Mean playing time for the forwards was 18:85 ± 1:15 min:s and playing time for the defense was 24:00 ± 2:46 min:s. Sweat loss was 3.2 ± 0.2 L and exceeded net fluid intake (2.1 ± 0.1 L). Mean BM loss was 1.3% ± 0.3%, with 8/24 players losing between 1.8% to 4.3% BM. Players preferred to drink water and a carbohydrate electrolyte solution before the game and during intermissions, while only water was consumed during each period. Practice mean forehead sweat [Na+] was 74 mmol·L-1. Estimated sweat Na+ losses of 3.1 ± 0.4 g (~8 g NaCl) coupled with low Na+ intake of 0.8 ± 0.2 g (~2 g NaCl) resulted in a significant Na+ deficit by the end of the game. This study demonstrated that despite abundant opportunities to hydrate during a hockey game, one-third of the players did not drink enough fluid to prevent sweat losses of 2% BM or higher. Losing 2% BM has been associated with decreases in athletic performance. PMID:21326389

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

2011-02-01

172

The effect of the mandatory use of face masks on facial lacerations and head and neck injuries in ice hockey. A prospective study.  

PubMed

A 4-year prospective review of lost-time injuries and facial lacerations was performed for a National Collegiate Athletic Association Division I, intercollegiate ice hockey team. The total injury exposure time consisted of 798.5 practice hours and 163 games. There were 16 facial lacerations, with an incidence of 14.9 per 1000 player-game hours and 0.1 per 1000 player-practice hours; both incidences were found to be less than in previous comparable studies where the use of face masks was not mandatory. In addition, there were eight lost-time head and neck injuries that accounted for 6.3% of all lost-time injuries. We found that the mandatory use of face masks in intercollegiate ice hockey results in a reduction in facial lacerations and no increase in overall head and neck injuries. PMID:8600750

LaPrade, R F; Burnett, Q M; Zarzour, R; Moss, R

1995-01-01

173

The Effect of the Mandatory Use of Face Masks on Facial Lacerations and Head and Neck Injuries in Ice HockeyA Prospective Study  

Microsoft Academic Search

A 4-year prospective review of lost-time injuries and fa cial lacerations was performed for a National Collegiate Athletic Association Division I, intercollegiate ice hockey team. The total injury exposure time consisted of 798.5 practice hours and 163 games. There were 16 facial lacerations, with an incidence of 14.9 per 1000 player-game hours and 0.1 per 1000 player-practice hours; both incidences

Robert F. LaPrade; Quinter M. Burnett; Robert Zarzour; Robert Moss

1995-01-01

174

Impact of Maximum Speed on Sprint Performance During High-Level Youth Female Field Hockey Matches: Female Athletes in Motion (FAiM) Study.  

PubMed

The aim of this study was to examine the impact of maximum sprint speed on peak and mean sprint speed during youth female field hockey matches. Two high-level female field hockey teams (U-17, n = 24, and U-21, n = 20) were monitored during a 4-game international test series using global position system technology and tested for maximum sprint speed. Dependent variables were compared using a 3-factor ANOVA (age group, position, and speed classification); effect sizes (Cohen d) and confidence limits were also calculated. Maximum sprint speed was similar between age groups and positions, with faster players having greater speed than slower players (29.3 ± 0.4 vs 27.2 ± 1.1 km/h). Overall, peak match speed in youth female field hockey players reaches approximately 90% of maximum sprint speed. Absolute peak match speed and mean sprint speed during matches were similar among the age groups (except match 1) and positions (except match 2); however, peak match speed was greater for faster players in matches 3 and 4. No differences were observed in the relative proportion for mean sprint speeds for age groups or positions, but slower players consistently displayed similar relative mean sprint speeds by using a greater proportion of their maximum sprint speed. PMID:24152425

Vescovi, Jason D

2014-07-01

175

Imagine Life without Friction  

NSDL National Science Digital Library

Students are introduced to the concept of inertia and its application to a world without the force of friction acting on moving objects. When an object is in motion, friction tends to be the force that acts on this object to slow it down and eventually come to a stop. By severely limiting friction through the use of hover pucks, students learn that the energy of one moving puck is transferred directly to another puck at rest when they collide. Students learn the concept of the conservation of energy via a "collision," and come to realize that with friction, energy is converted primarily to heat to slow and stop an object in motion. In the associated activity, "The Puck Stops Here," students investigate the frictional force of an object when different materials are placed between the object and the ground. They apply this understanding to the challenge to design a new hockey puck for the National Hockey League.

Engineering K-Phd Program

176

The Social Support Experiences of Major Junior Ice Hockey Players in a Physically Removed Region of Canada  

PubMed Central

The present report from a larger project overviews the sources and types of social support resourced by 10 major junior athletes while they performed out of one physically removed Canadian region. Retrospective interviews and content analysis were conducted during three stages (3, 3, and 4 respondents). The data were segmented into meaning units, coded into a hierarchy of themes, and verified by each respondent and an expert panel (former athlete, coach, parent of former athlete). The respondents sought out three types of social support from four different sources (providers) that were adapted to their remote location, including teachers and general community support. Implications are considered in terms of applied research and practice with aspiring adolescent athletes located in removed locations. Key pointsThe study extends knowledge about the sources and types of social support resourced by elite major junior ice hockey players located in one physically removed Canadian region.From the respondents’ views, three types of social support were sought from four different sources.Implications are considered in terms of sport psychology research and applied practice.

Dube, Timothy V.; Schinke, Robert J.; Hancock, David J.; Dubuc, Nicole G.

2007-01-01

177

Generic Hockey-Stick Model for Estimating Benchmark Dose and Potency: Performance Relative to BMDS and Application to Anthraquinone  

PubMed Central

Benchmark Dose Model software (BMDS), developed by the U.S. Environmental Protection Agency, involves a growing suite of models and decision rules now widely applied to assess noncancer and cancer risk, yet its statistical performance has never been examined systematically. As typically applied, BMDS also ignores the possibility of reduced risk at low doses (“hormesis”). A simpler, proposed Generic Hockey-Stick (GHS) model also estimates benchmark dose and potency, and additionally characterizes and tests objectively for hormetic trend. Using 100 simulated dichotomous-data sets (5 dose groups, 50 animals/group), sampled from each of seven risk functions, GHS estimators performed about as well or better than BMDS estimators, and a surprising observation was that BMDS mis-specified all of six non-hormetic sampled risk functions most or all of the time. When applied to data on rodent tumors induced by the genotoxic chemical carcinogen anthraquinone (AQ), the GHS model yielded significantly negative estimates of net potency exhibited by the combined rodent data, suggesting that—consistent with the anti-leukemogenic properties of AQ and structurally similar quinones—environmental AQ exposures do not likely increase net cancer risk. In addition to its simplicity and flexibility, the GHS approach offers a unified, consistent approach to quantifying environmental chemical risk.

Bogen, Kenneth T.

2010-01-01

178

Biomechanical analysis of the penalty-corner drag-flick of elite male and female hockey players.  

PubMed

The aim of this study was to analyse the kinematic sequencing in the penalty-corner drag-flicks of elite male and female field hockey players of international calibre. Thirteen participants (one skilled male drag-flicker and six male and six female elite players) participated in the study. An optoelectronic motion analysis system was used to capture the drag-flicks with six cameras, sampling at 250 Hz. Select ground reaction force parameters were obtained from a force platform which registered the last support of the front foot. Twenty trials were captured from each subject. Both player groups showed significantly (p < 0.05) smaller ball velocity at release, peak angular velocity of the pelvis, and negative and positive peak angular velocities of the stick than the skilled subject. Normalised ground reaction forces of the gender groups were also smaller than that of the skilled drag-flicker. By comparing these players we established that the cues of the skill level are a wide stance, a whipping action (rapid back lift) of the stick followed by an explosive sequential movement of the pelvis, upper trunk and stick. PMID:20806843

López de Subijana, Cristina; Juárez, Daniel; Mallo, Javier; Navarro, Enrique

2010-06-01

179

Effect of training on weight and certain physiological parameters of Indian female hockey players with respect to their field positions.  

PubMed

The present study was conducted on 18 female players of the Punjabi University hockey team during their camp held at Punjabi University from 4.10.1988 to 24.10.1988; before participating in the Inter-varsity competition held at Ranchi. Weight, heart rate and blood pressure of each subject was taken before doing the exercise on the treadmill. The players were asked to run on the treadmill for four minutes at the speed of 10 km/hr. Recovery heart rate and blood pressure were also taken. All these tests were taken twice on each player, i.e. initially at the commencement of the training and finally at the completion of the training camp. It has been observed that there is a reduction of body weight in all the categories of players, the maximum being in halves (2.5 kg). There is an improvement in the percentage recovery in the heart rates of all the categories of players except the halves where the recovery is much less at the end of the training camp as compared to the values in the beginning of the camp. PMID:2079843

Mokha, R; Sidhu, L S; Kaur, G; Singh, J

1990-12-01

180

Perfectionism and achievement goals in young Finnish ice-hockey players aspiring to make the Under-16 national team.  

PubMed

Research on perfectionism suggests that is it useful to differentiate between perfectionistic strivings and perfectionistic concerns. Regarding the 2x2 achievement goal framework, the usefulness of this differentiation was recently demonstrated in a study with university student athletes (Stoeber, Stoll, Pescheck, & Otto, 2008, Study 2), in which it was found that perfectionistic strivings were associated with mastery-approach and performance-approach goals and perfectionistic concerns with mastery-avoidance, performance-approach, and performance-avoidance goals. Because the study was largely exploratory and only used non-elite athletes, the aim of the present research was to replicate and extend these findings by investigating a sample of 138 young, elite ice-hockey players, while adding further measures of perfectionism and using structural equation modelling (SEM) to confirm the relationships between perfectionistic strivings, perfectionistic concerns, and the 2x2 achievement goals. The SEM results showed that, in elite athletes also, perfectionistic strivings are associated with mastery-approach and performance-approach goals, whereas perfectionistic concerns are associated with mastery-avoidance, performance-approach, and performance-avoidance goals. Our findings corroborate the importance of differentiating between perfectionistic strivings and perfectionistic concerns when studying perfectionism in sports, because only perfectionistic concerns (and not perfectionistic strivings) are associated with maladaptive patterns of achievement goals. PMID:19012074

Stoeber, Joachim; Stoll, Oliver; Salmi, Olli; Tiikkaja, Jukka

2009-01-01

181

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

PubMed

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

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

2010-06-01

182

Reliability, usefulness, and validity of the 30-15 Intermittent Ice Test in young elite ice hockey players.  

PubMed

The purpose of this study was to examine the reliability, usefulness, and validity of the 30-15 Intermittent Ice Test (30-15(IIT)) in 17 young elite ice hockey players. For the reliability and usefulness study, players performed the 30-15(IIT) 7 days apart. For the validity study, data derived from the first 30-15(IIT) were compared with those obtained from the 30-15 Intermittent Fitness Test (30-15(IFT), the running version of this test used as a reference marker for its ability to assess cardiovascular fitness in the field, that is, VO?peak). Maximal speed, heart rate at exhaustion (HR(peak)) and postexercise blood-lactate levels ([La](b)) were collected for all tests, whereas submaximal HR was taken at stages 4 and 8 (HR(stage4) and HR(stage8)) during the 30-15(IIT). All intra-class correlation coefficients were >0.94. Coefficients of variation were 1.6% (90% CI, 1.3-2.3), 1.7% (1.3-2.8), 1.4% (1.0-2.2), and 0.7% (0.5-1.1) for maximal skating speed, HR(stage4), HR(stage8), and HR(peak), respectively. Correlations between maximal velocities and HR(peak) obtained for the 30-15(IIT) vs. 30-15(IFT) were very large (r = 0.72) and large (r = 0.61), respectively. Maximal skating speed was also largely correlated to estimated VO?peak (r = 0.71). There was however no correlation for [La](b) values between both tests (r = 0.42). These results highlight the specificity of the on-ice 30-15(IIT) and show it to be a reliable and valid test for assessing cardiorespiratory fitness in young elite players. Coaches could interpret a change in performance of at least 2 stages, or a change in submaximal HR of more than 8% (?8 b·min?¹) during the eighth stage to be a meaningful change in skating fitness. PMID:21522077

Buchheit, Martin; Lefebvre, Benjamin; Laursen, Paul B; Ahmaidi, Said

2011-05-01

183

Knowing what to do and doing it: differences in self-assessed tactical skills of regional, sub-elite, and elite youth field hockey players.  

PubMed

To determine whether youth athletes with an "average" (regional), "high" (sub-elite), and "very high" (elite) level of performance differ with respect to their self-assessed tactical skills, 191 youth field hockey players (mean age 15.5 years, s = 1.6) completed the Tactical Skills Inventory for Sports (TACSIS) with scales for declarative ("knowing what to do") and procedural ("doing it") knowledge. Multivariate analyses of covariance with age as covariate showed that elite and sub-elite players outscored regional players on all tactical skills (P < 0.05), whereas elite players had better scores than sub-elite players on "positioning and deciding" (P < 0.05) only. The sex of the athletes had no influence on the scores (P > 0.05). With increasing level of performance, scores on declarative and procedural knowledge were higher. Close to expert performance, declarative knowledge no longer differentiated between elite and sub-elite players (P > 0.05), in contrast to an aspect of procedural knowledge (i.e. positioning and deciding), where elite players outscored sub-elite players (P < 0.05). These results may have implications for the development of talented athletes. PMID:20419593

Elferink-Gemser, Marije T; Kannekens, Rianne; Lyons, Jim; Tromp, Yvonne; Visscher, Chris

2010-03-01

184

The "hockey sticks" effect revisited: the conformational and electronic properties of 3,7-dithia-1,5-diazabicyclo[3.3.1]nonane from the QTAIM perspective.  

PubMed

The conformational effects in bicyclo[3.3.1]nonanes, while thoroughly studied, have not yet received the full theoretical explanation. R. F. W. Bader's quantum theory of atoms in molecules presents unique opportunities for studying the stereoelectronic interactions (SEI) and weak intramolecular bonding leading to these effects. Here, we report the study of 3,7-dithia-1,5-diazabicyclo[3.3.1]nonane by means of the topological analysis of the calculated (MP2(full)/6-311++G**) and experimental (X-ray derived) charge density to reveal the origins of the so-called "hockey sticks" effect observed in similar compounds. A new explanation of the relative stability of bicyclo[3.3.1]nonane conformers based on the analysis of the QTAIM atomic energies is given. The H···H and S···S interactions in bicyclo[3.3.1]nonane and its dithia derivatives are shown to be significant factors contributing to the differences in the relative stability of the conformers. PMID:21879771

Bushmarinov, I S; Fedyanin, I V; Lyssenko, K A; Lapteva, V L; Pisarev, S A; Palyulin, V A; Zefirov, N S; Antipin, M Yu

2011-11-17

185

Free-flying magnetometer data system architecture and hardware realization using commercial, off the shelf (COTS) technology  

Microsoft Academic Search

The Free-Flying Magnetometer (FFM) is an autonomous spin-stabilized “sensorcraft” developed for the Enstrophy sounding rocket mission. Four “hockey puck” FFMs were successfully ejected from the payload of a sounding rocket. The FFMs measured the vector magnetic field at 4 points separate from the payload at relative distances up to 3 km, and telemetered their data, in bursts, to the ground.

B. Blaes; H. Javadi; H. Spencer

1999-01-01

186

Skin conditions in figure skaters, ice-hockey players and speed skaters: part II - cold-induced, infectious and inflammatory dermatoses.  

PubMed

Participation in ice-skating sports, particularly figure skating, ice hockey and speed skating, has increased in recent years. Competitive athletes in these sports experience a range of dermatological injuries related to mechanical factors: exposure to cold temperatures, infectious agents and inflammation. Part I of this two part review discussed the mechanical dermatoses affecting ice-skating athletes that result from friction, pressure, and chronic irritation related to athletic equipment and contact with surfaces. Here, in Part II, we review the cold-induced, infectious and inflammatory skin conditions observed in ice-skating athletes. Cold-induced dermatoses experienced by ice-skating athletes result from specific physiological effects of cold exposure on the skin. These conditions include physiological livedo reticularis, chilblains (pernio), Raynaud phenomenon, cold panniculitis, frostnip and frostbite. Frostbite, that is the literal freezing of tissue, occurs with specific symptoms that progress in a stepwise fashion, starting with frostnip. Treatment involves gradual forms of rewarming and the use of friction massages and pain medications as needed. Calcium channel blockers, including nifedipine, are the mainstay of pharmacological therapy for the major nonfreezing cold-induced dermatoses including chilblains and Raynaud phenomenon. Raynaud phenomenon, a vasculopathy involving recurrent vasospasm of the fingers and toes in response to cold, is especially common in figure skaters. Protective clothing and insulation, avoidance of smoking and vasoconstrictive medications, maintaining a dry environment around the skin, cold avoidance when possible as well as certain physical manoeuvres that promote vasodilation are useful preventative measures. Infectious conditions most often seen in ice-skating athletes include tinea pedis, onychomycosis, pitted keratolysis, warts and folliculitis. Awareness, prompt treatment and the use of preventative measures are particularly important in managing such dermatoses that are easily spread from person to person in training facilities. The use of well ventilated footgear and synthetic substances to keep feet dry, as well as wearing sandals in shared facilities and maintaining good personal hygiene are very helpful in preventing transmission. Inflammatory conditions that may be seen in ice-skating athletes include allergic contact dermatitis, palmoplantar eccrine hidradenitis, exercise-induced purpuric eruptions and urticaria. Several materials commonly used in ice hockey and figure skating cause contact dermatitis. Identification of the allergen is essential and patch testing may be required. Exercise-induced purpuric eruptions often occur after exercise, are rarely indicative of a chronic venous disorder or other haematological abnormality and the lesions typically resolve spontaneously. The subtypes of urticaria most commonly seen in athletes are acute forms induced by physical stimuli, such as exercise, temperature, sunlight, water or particular levels of external pressure. Cholinergic urticaria is the most common type of physical urticaria seen in athletes aged 30 years and under. Occasionally, skaters may develop eating disorders and other related behaviours some of which have skin manifestations that are discussed herein. We hope that this comprehensive review will aid sports medicine practitioners, dermatologists and other physicians in the diagnosis and treatment of these dermatoses. PMID:21985216

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

2011-11-01

187

Campus Computing Looks Ahead: Tracking the Digital Puck.  

ERIC Educational Resources Information Center

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)

Green, Kenneth C.

2002-01-01

188

Safety Tips: Hockey (For Parents)  

MedlinePLUS

... flexors. Back Continue Keeping it Safe During a Game There's a reason why tripping, hooking, slashing, high- ... by theirs. Other penalties designed to keep the game safe involve roughing, boarding, and checking from behind. ...

189

The 'Patient experience' revolution.  

PubMed

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

Hooten, Doug; Zavadsky, Matt

2014-02-01

190

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

PubMed

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

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

2004-02-01

191

A Cool Sport Full of Physics  

NASA Astrophysics Data System (ADS)

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

Haché, Alain

2008-10-01

192

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

NASA Astrophysics Data System (ADS)

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 (22°S), Concepción (36°S), and Chiloé (42°S) 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.

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

2009-07-01

193

Depression research and treatment: Are we skating to where the puck is going to be?  

Microsoft Academic Search

This paper critically reviews empirical findings regarding current key assumptions underlying the nature and treatment of depression which heavily rely on the DSM approach. This review shows that empirical evidence provides little support for these assumptions. In response to these findings, an etiologically based, biopsychosocial, dynamic interactionism model of depression is proposed. This model could foster further integration in research

Patrick Luyten; Sidney J. Blatt; Boudewijn Van Houdenhove; Jozef Corveleyn

2006-01-01

194

Ultra-Compact Motor Controller  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

195

Augmented Reality Comes to Physics  

NASA Astrophysics Data System (ADS)

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.1 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.

Buesing, Mark; Cook, Michael

2013-04-01

196

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

PubMed Central

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

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

2012-01-01

197

Broken Bones, Concussions Most Common Injuries in Youth Hockey  

MedlinePLUS

... Dallas Thursday, June 5, 2014 Related MedlinePlus Pages Children's Health Sports Injuries THURSDAY, June 5, 2014 (HealthDay News) -- ... HealthDay . All rights reserved. More Health News on: Children's Health Sports Injuries Recent Health News Page last updated ...

198

Video Gaming Promotes Concussion Knowledge Acquisition in Youth Hockey Players  

ERIC Educational Resources Information Center

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…

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

2006-01-01

199

Experimental measurement and numerical simulation of residual stresses in a carburized layer of a 5120 steel  

SciTech Connect

A combined experimental and numerical study of residual stress and microstructure has been performed for a carburized steel 5120 specimen. Specimens were cut from 5120 steel bar stock, in the shape of hockey pucks and were subsequently carburized and quenched. X-ray diffraction was used to record stress profiles through the case for the martensite and retained austenite on the two flat surfaces oriented up and down during the quench. Layer removal was performed by electropolishing. Rietveld analysis was used to determine the lattice parameters of the phases at each depth varying with both carbon content and stress. The experimental measurements are compared with a numerical simulation of the phase transformation and the metallurgical changes following the carburization and quench. Results am discussed in the context of the microstructure and the role played by the retained austenite in interpretation. In addition the carbon profile obtained from the lattice parameters is compared with profiles measured using burnout.

Rangaswamy, P.; Bourke, M.A.M.; Shipley, J.C.; Goldstone, J.A.

1995-09-01

200

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

ERIC Educational Resources Information Center

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'…

Smith, Kristy L.; Weir, Patricia L.

2013-01-01

201

Minor Traumatic Brain Injury (mTBI) in Ice Hockey and Other Contact Sports  

Microsoft Academic Search

Minor Traumatic Brain Injury (mTBI) is caused by the inertial effect of a mechanical impact to the head with sudden rotational acceleration forces. MTBI produces, in the less severe cases, only transient disturbances of ionic homeostasis with temporary disturbances of brain function. Depending on the severity of the trauma, animal and human studies have demonstrated focal intraaxonal alterations in neurofilamentous\\/cytoskeletal

Nicola Biasca; Stephan Wirth; William Maxwell; Hans-Peter Simmen

2005-01-01

202

In situ removal of the ``hockey stick`` fissile material deposit at the East Tennessee Technology Park  

Microsoft Academic Search

Prior to shutdown of the gaseous diffusion process at the Oak Ridge K-25 Plant (now East Tennessee Technology Park), leakage of humid air into the process piping and equipment caused reactions with UFâ, which produced nonvolatile uranyl fluoride (UOâFâ) deposition and other solid uranium fluoride compounds. During the period 1988--1991, Lockheed Martin Energy Systems performed nondestructive analysis (NDA) radiological surveys

K. D. Lewis; D. A. Tollefson

1998-01-01

203

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

ERIC Educational Resources Information Center

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…

Jacobsen, Michele; Tate, Joanne

204

Adductor tendinopathy in a hockey player with persistent groin pain: a case report  

PubMed Central

Groin pain may stem from a variety of different causes. Adductor tendinopathy is a common but infrequently recognised cause of chronic groin pain especially in athletes. This case report describes a case of clinically suspected adductor tendinopathy in an amateur athlete confirmed by MRI (Magnetic Resonance Imaging). Relevant literature on musculotendinous injuries of the groin along with differential diagnosis for groin pain is discussed. There are several differential diagnoses for athletes that present with groin pain. Therefore, it is important to accurately diagnose the origin of groin pain as the plan of management is dependent of the specificity of the diagnosis. The diagnosis of adductor tendinopathy is made with a history of chronic groin pain along with pain/weakness during isometric adduction of the hip muscles. It is confirmed by MR imaging.

Avrahami, Daniel; Choudur, Hema N.

2010-01-01

205

Seasonal variation in fitness in a women's National League hockey squad  

Microsoft Academic Search

Regular fitness assessments are crucial in monitoring the efficacy of a training programme, judging return to play after injury and motivating athletes. The data can be used by practitioners to track differences in fitness at specific time points in the season or between playing positions. This study presents three seasons of test data in an elite women's squad, covering their

E Jones; A McGregor

2010-01-01

206

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

ERIC Educational Resources Information Center

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…

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

2008-01-01

207

Place Identity and Sport Tourism: The Case of the Heritage Classic Ice Hockey Event  

Microsoft Academic Search

Sport is an important factor in the construction of place identity. This is particularly evident in the case of nostalgia based sport events that have been consciously developed in an attempt to influence destination image. It is unclear, however, just how much influence attraction planners have on identity in the face of varying media interpretations. This paper examines the way

Greg Ramshaw; Tom Hinch

2006-01-01

208

Heritage, sport tourism and Canadian junior hockey: nostalgia for social experience or sport place?  

Microsoft Academic Search

North American cities, working with their respective sports franchises, have built new facilities which have deliberately embraced romanticized notions of their sporting pasts. In this instance, the nostalgia experience is tied closely to the facility itself. However, not all sports facilities have embraced heritage elements in their design and used heritage as a vehicle for nostalgia sport tourism. Facilities built

Daniel S. Mason; Gregory H. Duquette; Jay Scherer

2005-01-01

209

An Experimental Investigation of Detonation Corner-Turning Using High Resolution Radiography  

SciTech Connect

We have performed experiments investigating detonation corner turning over a range of high-explosives including LX-17, Composition B, LX-04 and Tritonal. The primary diagnostic utilized here was a new high-resolution x-ray system that was capable of recording a time sequence of the detonation process as it negotiated the corner of interest and propagated. For LX-17 our data detail the formation of a significant dead-zone. Although the detonation eventually turned the corner in LX-17, the dead zone persisted to late times and evidence exists that it never was consumed by either detonation or fast combustion processes. In LX-17 the detonations ability to corner-turn increases as the density is reduced. Furthermore, lowering the density decreases the size of the dead-zone and alters its shape. The other high-explosives investigated were able to turn the corner immediately with no indication of any dead-zone formation.

Molitoris, J D; Andreski, H G; Garza, R G; Batteux, J D; Souers, P C

2006-07-19

210

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

NASA Astrophysics Data System (ADS)

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. .

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

2001-02-01

211

One Dimensional Motion: Position versus Time Graphs  

NSDL National Science Digital Library

In the following exercises, the graph drawn is of position versus time. The animation shows the position of a puck as time progresses. Note the position of the puck at various times and compare the animation to the graph.

Christian, Wolfgang; Belloni, Mario

2008-02-19

212

Where did National Hockey League Fans go During the 2004-2005 Lockout?: An Analysis of Economic Competition Between Leagues  

Microsoft Academic Search

Identifying and evaluating competitors is a critical aspect of operating a sport organisation. However, North American sports franchises have a limited understanding of competitors in their geographic market – particularly when calculating the degree of competition from other sport teams. Increasing the understanding of local sport competitors, whether in the same or different professional leagues, is critical not only to

Daniel A. Rascher; Matthew T. Brown; Mark S. Nagel; Chad D. McEvoy

2009-01-01

213

Perfectionism and achievement goals in young Finnish ice-hockey players aspiring to make the Under16 national team  

Microsoft Academic Search

Research on perfectionism suggests that is it useful to differentiate between perfectionistic strivings and perfectionistic concerns. Regarding the 2 × 2 achievement goal framework, the usefulness of this differentiation was recently demonstrated in a study with university student athletes (Stoeber, Stoll, Pescheck, & Otto, 2008, Study 2), in which it was found that perfectionistic strivings were associated with mastery-approach and performance-approach goals

Joachim Stoeber; Oliver Stoll; Olli Salmi; Jukka Tiikkaja

2009-01-01

214

Experimental Measurements and Numerical Simulations of Metal Spallation by Detonating Solid Explosives.  

National Technical Information Service (NTIS)

Fabry-Perot laser interferometric measurements of the free surface velocities of tantalum and copper plates spalled by the detonating solid explosives LX-14, LX-17 and RX-26-AF are reported. Numerical calculations using the ignition and growth reactive fl...

C. M. Tarver D. E. Maiden

1987-01-01

215

Ultra-Compact Motor Controller  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

216

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

PubMed Central

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

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

2007-01-01

217

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

218

Experimental measurements and numerical simulations of metal spallation by detonating solid explosives  

SciTech Connect

Fabry-Perot laser interferometric measurements of the free surface velocities of tantalum and copper plates spalled by the detonating solid explosives LX-14, LX-17 and RX-26-AF are reported. Numerical calculations using the ignition and growth reactive flow model for the detonating explosive, the Steinberg-Guinan high strain rate constitutive model for the metal, and two different spall models are shown to accurately simulate the experimental records.

Tarver, C.M.; Maiden, D.E.

1987-07-14

219

Experimental measurements and numerical simulations of metal spallation by detonating solid explosives  

Microsoft Academic Search

Fabry-Perot laser interferometric measurements of the free surface velocities of tantalum and copper plates spalled by the detonating solid explosives LX-14, LX-17 and RX-26-AF are reported. Numerical calculations using the ignition and growth reactive flow model for the detonating explosive, the Steinberg-Guinan high strain rate constitutive model for the metal, and two different spall models are shown to accurately simulate

C. M. Tarver; D. E. Maiden

1987-01-01

220

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

Microsoft Academic Search

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

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

2008-01-01

221

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

Microsoft Academic Search

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

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

2008-01-01

222

Plutonium immobilization feed batching system concept report  

SciTech Connect

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 high level waste glass for permanent storage. Feed batching is one of the first process steps involved with first stage plutonium immobilization. It will blend plutonium oxide powder before it is combined with other materials to make pucks. This report discusses the Plutonium Immobilization feed batching process preliminary concept, batch splitting concepts, and includes a process block diagram, concept descriptions, a preliminary equipment list, and feed batching development areas.

Erickson, S.

2000-07-19

223

Plutonium Immobilization Can Loading Conceptual Design  

SciTech Connect

'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.'

Kriikku, E.

1999-05-13

224

Development of the Direct Fabrication Process for Plutonium Immobilization  

SciTech Connect

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.

Congdon, J.W.

2001-07-10

225

Mimas: Tectonic Structure and Geologic History.  

National Technical Information Service (NTIS)

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...

S. K. Croft

1991-01-01

226

Control System for the Stacker Unstacker System for the Plutonium Immobilization Project  

SciTech Connect

The disposition of excess plutonium will incorporate plutonium in ceramic pucks and seal the picks in cans. Remote equipment will place these cans in magazines in a Defense Waste Processing Facility canister.

Fields, T.

2001-01-31

227

Plutonium Immobilization Project -- Can loading  

SciTech Connect

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 fills the canister with a mixture of high level radioactive waste and glass for permanent storage. Due to the radiation, remote equipment must perform PIP operations in a contained environment.

Kriikku, E.

2000-01-18

228

Control System for the Stacker Unstacker System for the Plutonium Immobilization Project  

SciTech Connect

The disposition of excess plutonium will incorporate plutonium in ceramic pucks and seal the picks in cans. Remote equipment will place these cans in magazines in a Defense Waste Processing Facility canister.

Fields, T.

2001-01-03

229

Promoting the ‘arriviste’ city: Producing neoliberal urban identity and communities of consumption during the Edmonton Oilers’ 2006 playoff campaign  

Microsoft Academic Search

In the spring of 2006, the National Hockey League’s (NHL) Edmonton Oilers made a surprise run to the Stanley Cup final for the first time in 16 years. Predictably, hockey fans and media pundits responded enthusiastically to the one-time return to glory of their men’s professional hockey team. Drawing from threads of political economy, historical analysis, cultural studies and queer

Jay Scherer; Judy Davidson

2011-01-01

230

Skill Acquisition in Students with and without Pervasive Developmental Disorder  

ERIC Educational Resources Information Center

The purposes of this study were (a) to examine skill acquisition in field hockey of seven junior-high school students with PDD, who attended an inclusive class; and (b) to compare the degree of skill acquisition in field hockey of junior-high school students without disabilities who attend an inclusive class and those who attend a regular class.…

Hutzler, Yeshayahu; Margalit, Matan

2009-01-01

231

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

ERIC Educational Resources Information Center

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)

Borozne, Joseph, Ed.; And Others

232

Free-Flying Magnetometer Data System  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

233

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

SciTech Connect

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.

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

1994-03-01

234

NOTE: Red, Gray, and Blue: Near Infrared Spectrophotometry of Faint Moons of Uranus and Neptune  

NASA Astrophysics Data System (ADS)

Using the CoCo Cold Coronagraph at NASA's Infrared Telescope Facility on Mauna Kea, we observed the uranian satellites Miranda, Puck, Portia, and Rosalind and the neptunian satellite Proteus in the near infrared (JHK) to determine the albedos of those faint satellites. In V-J, all of Puck, Portia, Rosalind, and Proteus are very blue, similar to the colors of many icy satellites and of water ice. The satellites we observed have a wide range of J-H colors, with Miranda being blue, Proteus being gray, and Puck, Portia, and Rosalind being red. For the satellites for which we could determine H-K (Miranda, Puck, and Proteus), the colors are gray to red. As a whole, spectrally, these five satellites lie between icy Solar System satellites (e.g., saturnian satellites or the major uranian satellites) and Kuiper belt objects. The redness of Proteus and Puck and perhaps other satellites suggests the presence of organic material, although the redness is also similar to that of C- and D-class asteroids and some outer jovian moons. In all cases, diagnostic spectral features could be masked by broadband photometry.

Trilling, David E.; Brown, Robert H.

2000-11-01

235

Insensitive fuze train for high explosives  

DOEpatents

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.

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

1994-01-04

236

Insensitive fuze train for high explosives  

DOEpatents

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.

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

1994-01-01

237

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

NASA Astrophysics Data System (ADS)

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

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

1999-06-01

238

Plutonium Immobilization Can Loading Concepts  

SciTech Connect

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.

Kriikku, E. [Westinghouse Savannah River Company, AIKEN, SC (United States); Ward, C.; Stokes, M.; Randall, B.; Steed, J.; Jones, R.; Hamilton, L.; Rogers, L.; Fiscus, J.; Dyches, G.

1998-05-01

239

Plutonium immobilization ceramic feed batching component test report  

SciTech Connect

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 high level waste glass for permanent storage. Ceramic feed batching (CFB) is one of the first process steps involved with first stage plutonium immobilization. The CFB step will blend plutonium oxide powder before it is combined with other materials to make pucks. This report discusses the Plutonium Immobilization CFB process preliminary concept (including a process block diagram), batch splitting component test results, CFB development areas, and FY 1999 and 2000 CFB program milestones.

Erickson, S.A.

1999-10-04

240

Plutonium Immobilization Can Loading FY98 Year End Design Report  

SciTech Connect

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.

Kriikku, E.

1998-11-25

241

Remote handling in the Plutonium Immobilization Project -- Second stage immobilization  

SciTech Connect

The Savannah River Site (SRS) will immobilize excess plutonium in ceramic pucks and seal the pucks inside welded cans. Automated 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. Due to the radiation, remote equipment will perform these operations in a contained environment. The Plutonium Immobilization Project is in the conceptual design stage and the facility will begin operation in 2008. This paper discusses the Plutonium Immobilization Project phase 2 automation equipment conceptual design, equipment design, and work completed.

Kriikku, E.

1999-12-21

242

Plutonium Immobilization Can Loading Conceptual Design for 13 MT Case  

SciTech Connect

The Plutonium Immobilization Plant (PIP) 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 for the 13 Metric Ton (MT) PIP throughput case. This report includes a process block diagram, process description, and preliminary equipment specifications and documents the changes to the original can loading concept documented in previous reports.

Peterson, K.D.

2001-01-31

243

Probabilistic Threshold Criterion  

SciTech Connect

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.

Gresshoff, M; Hrousis, C A

2010-03-09

244

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

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.

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

245

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

SciTech Connect

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.

Willey, T M; Overturf, G

2009-03-26

246

Dealing with Sports Injuries  

MedlinePLUS

... TOPIC Safety Tips: Hockey Safety Tips: Running Physical Therapy Knee Injuries Sports Center Sports Physicals Sports and Exercise Safety Safety Tips: Basketball Anterior Cruciate Ligament (ACL) Injuries Safety Tips: Soccer Contact Us Print ...

247

How to Succeed in Business.  

ERIC Educational Resources Information Center

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)

Arnold, Josh

1996-01-01

248

Coming of Age: Sports Fiction for YAs.  

ERIC Educational Resources Information Center

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)

Brown, Ron

1982-01-01

249

45 CFR 86.41 - Athletics.  

Code of Federal Regulations, 2010 CFR

...offered unless the sport involved is a contact sport. For the purposes of this part, contact sports include boxing, wrestling, rugby, ice hockey, football, basketball and other sports the purpose of major activity of which involves bodily contact....

2009-10-01

250

Moraxella Catarrhalis: A Common Cause of Childhood Illnesses  

MedlinePLUS

... to Prevent SIDS Allergic Reactions Caused By Food Allergies Protective Eyewear Reduces Risk of Head, Eye and Face Injuries in Field Hockey Study Outlines Common Risky Behaviors of Children Struck by ...

251

Von Willebrand Disease  

MedlinePLUS

... Normally, when someone bleeds, small cells in the blood called platelets plug the hole. With the help of calcium, ... like football and hockey, but other sports and activities are usually OK. If someone with vWD starts ...

252

Guide to Safety for Young Athletes  

MedlinePLUS

... pitcher, a helmet and body padding for ice hockey) Know how to correctly use athletic equipment (for ... creating an atmosphere that promotes teamwork and sportsmanship. Youth sports should always be fun. The "win at ...

253

Concussion - child - discharge  

MedlinePLUS

... doctor first: Playing contact sports, such as football, hockey, and soccer Riding a bicycle, motorcycle, or off- ... Clinical report -- sport-related concussion in children and adolescents. AmericanAcademy of Pediatrics; Council on Sports Medicine and ...

254

18 CFR 1317.415 - Access to course offerings.  

Code of Federal Regulations, 2013 CFR

...students by sex within physical education classes or activities during participation in wrestling, boxing, rugby, ice hockey, football, basketball, and other sports the purpose or major activity of which involves bodily contact. (4) Where use of a...

2013-04-01

255

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 ...

256

Testicular Injuries  

MedlinePLUS

... re speeding along on your bike and you hit a big bump. All result in one really ... participating in sports where your testicles might get hit or kicked, like football, hockey, soccer, or karate. ...

257

Physics Notes  

ERIC Educational Resources Information Center

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…

School Science Review, 1972

1972-01-01

258

Discrepant Results in a 2-D Marble Collision  

ERIC Educational Resources Information Center

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…

Kalajian, Peter

2013-01-01

259

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

ERIC Educational Resources Information Center

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)

Pereira, Neves

1988-01-01

260

Shakespeare  

NSDL National Science Digital Library

Helping students to see that themes repeat themselves throughout time allows them to see inside their own hearts more clearly. Use these sites to learn more about William Shakespeare and his time. Shakespeare for Kids Queen Elizabeth Puck s Place You can add your own sonnets or pictures Go inside the Globe Theatre ...

Steele, Karen

2007-01-16

261

Shopping for Science.  

ERIC Educational Resources Information Center

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…

Ward, John; And Others

1992-01-01

262

Numerical Analysis of the Demagnetization Effect in a Superconducting Machine With Bulk HTS Material on the Rotor  

Microsoft Academic Search

When a bulk superconducting material is used as the magnets of an electric motor, the magnetized superconducting pucks are subjected to a varying magnetic field which has a detrimental effect on the trapped field. This may lead to a long term decay of the magnetization of the bulk superconductors. In this paper, we analyze numerically the demagnetization effect on bulk

Zhiyong Hong; Yudong Jiang; Ruilin Pei; Weijia Yuan; Richard Marchant; Tim A. Coombs

2009-01-01

263

Nonlinear Stability of Triangular Equilibrium Point in the Generalized Photogravitational Chermnykh-Like Problem  

Microsoft Academic Search

In 2006, an outer ring-moon system composed by the satellites Portia, Rosalind, Puck, and Mab, and two tenuous rings µ and nu, was discovered around Uranus by Showalter Lissauer (2006). We present the results of numerical simulations of an ensemble of micrometric particles of both rings disturbed by a combination of the solar radiation pressure force, the gravitational interaction with

Badam Singh Kushvah

2010-01-01

264

Acta Ornithologica. Volume 12, Numbers 1, 2, 4-7, 8, 1970.  

National Technical Information Service (NTIS)

Contents: Bird ringing report; Contributions to the avifauna of Poland; Water birds observed in the Gulf of Puck and its coast near Wladyslawowo (Baltic Coast); Snow goose in Poland; L. Lapland Bunting in Poland; New records of the Gull-billed Tern in Pol...

1973-01-01

265

Development of the Molecular Adsorber Coating for Spacecraft and Instrument Interiors  

NASA Technical Reports Server (NTRS)

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.

Abraham, Nithin

2011-01-01

266

Energetic materials destruction using molten salt  

SciTech Connect

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.

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

1994-04-29

267

Reaction zone structure in supracompressed detonating explosives  

SciTech Connect

Nanosecond time resolved particle velocity histories of supracompressed detonation waves in TNT-, TATB-, and HMX-based explosives are measured using a VISAR laser velocimeter and calculated using the ignition and growth reactive flow hydrodynamic computer code model. The Zeldovich-von Neumann-Doering (ZND) detonation wave structure is observed at pressures more than twice the self-sustaining detonation wave pressure. TNT and TATB exhibited a fast reaction which liberates approximately 80% of the total available exothermicity within 50 ns, followed by a slower reaction which lasts another 100--200 ns. These reaction rates are not strongly dependent on the initial shock pressure. The slower reaction is attributed to diffusion controlled solid carbon coagulation. The ignition and growth model using a ZND type model with a fast reaction preceding a slower reaction to the fully reacted product state accurately calculates the VISAR experimental data for TNT, LX-17, PBX 9404 and RX-26-AF. 21 refs., 15 figs., 3 tabs.

Green, L.G.; Tarver, C.M.; Erskine, D.J.

1989-08-18

268

TARANTULA 2011 in JWL++  

SciTech Connect

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.

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

2011-10-27

269

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

SciTech Connect

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.

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

270

Effects of different types of weight-bearing loading on bone mass and size in young males: a longitudinal study.  

PubMed

Whether different types of weight bearing loading have different effects on bone mineral accrual in young adults is not well investigated. We measured bone mineral density (BMD, g/cm(2)), bone mineral content (BMC, grams), and bone area (cm(2)) at different sites, in 46 ice hockey players, 18 badminton players and 27 controls, all 17 years of age. A follow up was conducted four years later. The gains in BMD and BMC of the femoral neck and in BMC of the humerus were significantly higher (p<0.05) in badminton players compared with controls during the follow-up time. The badminton players also gained more hip BMC and area compared with the ice hockey players (p<0.05). At the follow-up, the badminton players had higher BMD and BMC at all sites compared with controls (p<0.05). After adjustment for body weight, badminton players had higher hip BMD and BMC, femoral neck BMC, and humeral BMC compared with ice hockey players (p<0.05) at the follow-up. After adjustment for differences in age, there were no differences in BMC or BMD among fathers of badminton players, ice hockey players, or controls, suggesting an absence of selection bias. In conclusion, the novel results of the present study suggest that badminton is associated with higher gains in bone mass and size compared with ice hockey after puberty in men. These differences might be associated with higher strains on the bones from badminton play. PMID:18191629

Nordström, Anna; Högström, Magnus; Nordström, Peter

2008-03-01

271

ARROW-PAK Macroencapsulation. Innovative Technology Summary Report  

SciTech Connect

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

None

2002-04-01

272

Spectrophotometry of Small Uranian Satellites  

NASA Astrophysics Data System (ADS)

We observed the inner Uranian satellites Miranda, Puck, Portia, and Juliet over the wavelength range 0.25 to 0.80 microns. The observations were made 18 August 1996 with the red channel of the Faint Object Spectrograph of the HST, using the prism disperser. Miranda and Puck were definitely detected, with blue reflectance spectra over the range observed. Continuum slopes between -5 and -10 % per 1000 Angstroms$ are observed. Confirmation of detections of Portia and Juliet require more extensive analysis of the scattered light background and solar spectrum. Preliminary analysis indicates that they too are blue, at least in the 0.6 to 0.8 micron range. This work is based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This work was supported by STScI Grant GO-6487.

Storrs, A. D.; Zellner, B.; Wells, E. N.; Buratti, B.; Currie, D.; Seidelmann, K.; Pascu, D.

1996-09-01

273

Discrepant Results in a 2-D Marble Collision  

NASA Astrophysics Data System (ADS)

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.

Kalajian, Peter

2013-03-01

274

Carbon monoxide and nitrogen dioxide exposures in indoor ice skating rinks.  

PubMed

Exposures to carbon monoxide (CO) and nitrogen dioxide (NO2) were determined in seven enclosed ice skating rinks and an outdoor rink. The uptake of CO was also determined by the difference in alveolar CO concentration of the non-smoking hockey players before and after games. Carbon monoxide concentrations in enclosed rinks ranged from 4 to 117 ppm and NO2 concentrations from 342 to 2729 ppb for 2 h hockey games. The CO uptakes were linearly related to the ambient CO concentrations. Alveolar CO of the hockey players increased on average by 0.53 ppm per 1 ppm CO exposure over 2 h. Considering the CO and NO2 levels currently measured in enclosed ice skating rinks, indoor air quality guidelines or standards should be established. It is recommended that 1 h maximum allowable limits of 20 ppm CO and 250 ppb NO2 be established. PMID:8064974

Lee, K; Yanagisawa, Y; Spengler, J D; Nakai, S

1994-06-01

275

Changes in X-ray Sensitivity of HeLa Cells during the Division Cycle  

Microsoft Academic Search

MEASUREMENT by Puck and Marcus of the reproductive survival of randomly dividing cultures of HeLa S3 cells after X-irradiation revealed an exponential response to dose following a shoulder1. However, the possibility was not excluded that these populations are in fact heterogeneous, the cells undergoing small, or large but brief, fluctuations in sensitivity during the division cycle. We have examined this

Toyozo Terasima; L. J. Tolmach

1961-01-01

276

Spectrophotometry of Inner Satellites of Uranus  

Microsoft Academic Search

We propose spectrophotometry with the FOS\\/Red of the innerUranian satellites Puck, Portia, and Juliet, which areimpossible to observe from the ground. Small apertures willbe used for accurate measurements of the scattered light fromUranus, and we expect to get good spectra over the wavelengthrange 0.28 to 0.80 microns. We will also obtain a high-quality spectrum of Miranda to wavelengths as short

Benjamin Zellner

1996-01-01

277

Illinois PER Interactive Examples: Disk and String  

NSDL National Science Digital Library

This interactive homework problem requires the student to determine the fraction of a disk's total kinetic energy due to the rotation of a puck resting on a horizontal frictionless plane with a string wound around it and pulled on with constant force. The problem is accompanied by a sequence of questions designed to encourage critical thinking and conceptual analysis. It is part of a larger collection of interactive problems developed by the Illinois Physics Education Research Group.

Gladding, Gary

2008-07-09

278

Magnetorheological finishing of a diamond turned poly(methylmethacrylate) flat  

Microsoft Academic Search

Magnetorheological finishing (MRF) of a diamond turned poly(methymethacrylate) (PMMA) flat was demonstrated using a commercial Q22Y MRF machine and a zirconia-based magnetorheological (MR) fluid. The surface of a 38mm diameter by 7.6mm thick puck was processed in a sequence of two figure correction runs. The initial p-v wave front error of 4.5mum was reduced to 0.35 mum, and the average

Jessica E. DeGroote; Stephen D. Jacobs; John M. Schoen; Henry J. Romanofsky; Irina A. Kozhinova

2003-01-01

279

Dual-band, dual-polarization, interleaved cross-dipole and cavity-backed disc elements phased array antenna  

Microsoft Academic Search

In ship, submarine, or airborne satellite communication or multi-function radar operations, dual-band phased array antennas with dual-linear or circular polarizations are needed. We present a dual-band\\/dual-polarization phased array design using a interleaved cross-dipole radiator and a cavity-backed disk radiator in the same lattice structure. The low band radiator is a disk radiator sitting on top of a dielectric puck in

Kuan Min Lee; A. T. S. Wang; Ruey Shi Chu

1997-01-01

280

Somatotypes of Nigerian athletes of several sports.  

PubMed Central

Somatotype ratings and percentage body fat of 131 elite Nigerian male athletes, average 24.2 years of age, and belonging to badminton (n = 18), basketball (n = 30), field hockey (n = 24), handball (n = 16), judo (n = 18), and soccer (n = 25) teams were determined. Basketball, handball and soccer players were taller and heavier, and had low percent fat values as compared with the other athletic groups. Judokas and hockey players were endomesomorphs. Other sports groups were predominantly ectomesomorphs. Images p219-a p219-b p219-c

Mathur, D N; Toriola, A L; Igbokwe, N U

1985-01-01

281

Regressing Team Performance on Collective Efficacy: Considerations of Temporal Proximity and Concordance  

Microsoft Academic Search

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 for at least 7 weekends. Questionnaires were completed within

Nicholas D. Myers; Craig A. Paiement; Deborah L. Feltz

2007-01-01

282

Energy Consumption of Sport Halls.  

National Technical Information Service (NTIS)

The energy consumption of Finland's sports halls (ball games halls, ice hockey halls and swimming halls) represent approximately 1% of that of the country's whole building stock. In the light of the facts revealed by the energy study the potential energy ...

1983-01-01

283

A Survey to Determine to What Extent Ohlone College Is Meeting the Needs of Student Athletes.  

ERIC Educational Resources Information Center

A questionnaire was administered to all 1978 fall quarter student athletes at Ohlone College (California) to assess their goals and needs, and to find out to what degree student experience matched expectation. There was an 86% (N=85) response rate from the varsity men and women teams (volleyball, field hockey, soccer, water polo, and football).…

Baker, John

284

Carbon monoxide and nitrogen dioxide exposures in indoor ice skating rinks  

Microsoft Academic Search

Exposures to carbon monoxide (CO) and nitrogen dioxide (NO2) were determined in seven enclosed ice skating rinks and an outdoor rink. The uptake of CO was also determined by the difference in alveolar CO concentration of the non?smoking hockey players before and after games. Carbon monoxide concentrations in enclosed rinks ranged from 4 to 117 ppm and NO2 concentrations from

Kiyoung Lee; Yukio Yanagisawa; John D. Spengler; Satoshi Nakai

1994-01-01

285

Skating Injuries and Their Treatment  

PubMed Central

There are approximately 682 figure skating clubs in Canada (not including hockey or general recreational figure skating), with anywhere up to 600 or more members. This means that there are probably over 200,000 figure skaters in Canada today. This article deals with the general and specific medical problems that face these skaters, and what a physician should know about treating them.

Lemasters, George S.

1972-01-01

286

Battling fire and ice: remote guidance ultrasound to diagnose injury on the International Space Station and the ice rink  

Microsoft Academic Search

BackgroundNational Aeronautical and Space and Administration (NASA) researchers have optimized training methods that allow minimally trained, non-physician operators to obtain diagnostic ultrasound (US) images for medical diagnosis including musculoskeletal injury. We hypothesize that these techniques could be expanded to non-expert operators including National Hockey League (NHL) and Olympic athletic trainers to diagnose musculoskeletal injuries in athletes.

David Kwon; J. Antonio Bouffard; Marnix van Holsbeeck; Asot E. Sargsyan; Douglas R. Hamilton; Shannon L. Melton; Scott A. Dulchavsky

2007-01-01

287

Recovery of Heat from the Refrigeration Plant at the Bjoerkaeng Stadium in Huddinge.  

National Technical Information Service (NTIS)

The report describes an investigation of heat recovery from the refrigeration plant at the ice hockey rinks outdoors and in the stadium building at the Bjoerkaeng athletics centre. Heat emitted by the refrigeration plant is utilized for heating of the sta...

L. O. Glas

1984-01-01

288

Building Blueprints: Ice Is Nice.  

ERIC Educational Resources Information Center

Examines how one college developed a partnership with the city's professional hockey team to build an ice rink that would benefit the team, the university, and the community. The construction process is briefly described, and other renovations that occurred as a result of the project are highlighted. (GR)

Kollie, Ellen

1999-01-01

289

Observed decreases in the Canadian outdoor skating season due to recent winter warming  

Microsoft Academic Search

Global warming has the potential to negatively affect one of Canada’s primary sources of winter recreation: hockey and ice skating on outdoor rinks. Observed changes in winter temperatures in Canada suggest changes in the meteorological conditions required to support the creation and maintenance of outdoor skating rinks; while there have been observed increases in the ice-free period of several natural

Nikolay N Damyanov; H Damon Matthews; Lawrence A Mysak

2012-01-01

290

Athletes, Doctors, and Lawyers with First Names Beginning with “D” Die Sooner  

Microsoft Academic Search

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, dermatologists, obstetricians\\/gynecologists) and lawyers for comparison purposes. There was a progressive

Ernest L. Abel; Michael L. Kruger

2009-01-01

291

The Lived Experience of a Doctoral Student: The Process of Learning and Becoming  

ERIC Educational Resources Information Center

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…

Callary, Betina; Werthner, Penny; Trudel, Pierre

2012-01-01

292

Athletes, Doctors, and Lawyers with First Names Beginning with "D" Die Sooner  

ERIC Educational Resources Information Center

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,…

Abel, Ernest L.; Kruger, Michael L.

2010-01-01

293

What Can I Do to Help Prevent Traumatic Brain Injury?  

MedlinePLUS

... driving while under the influence of alcohol or drugs. Wearing a helmet and making sure your children wear helmets when: Riding a bike, motorcycle , snowmobile, scooter, or all-terrain vehicle; Playing a contact sport, such as football, ice hockey, or boxing; Using ...

294

The Value of Public Goods Generated by a Major League Sports Team: The CVM Approach  

Microsoft Academic Search

This article reports an application of the contingent valuation method to measure the value of public goods generated by a professional sports team, the Pittsburgh Penguins of the National Hockey League. The data and analysis indicate that a major league sports team can produce widely consumed public goods such as civic pride and community spirit and that the value of

Bruce K. Johnson; Peter A. Groothuis; John C. Whitehead

2001-01-01

295

Beyond Women's Collegiate Athletics. Opportunities to Play for Pay.  

ERIC Educational Resources Information Center

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)

Lehr, Carolyn A.; Washington, Martha A.

1987-01-01

296

Girls Physical Education Handbook.  

ERIC Educational Resources Information Center

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,…

Fairfax County Schools, VA.

297

1997 Arthur Ashe Jr. Sport Scholars Awards.  

ERIC Educational Resources Information Center

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…

Roach, Ronald

1997-01-01

298

Modifying Intramural Rules.  

ERIC Educational Resources Information Center

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)

Rokosz, Francis M.

1981-01-01

299

A Case Study of Wikis and Student-Designed Games in Physical Education  

ERIC Educational Resources Information Center

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…

Hastie, Peter A.; Casey, Ashley; Tarter, Anne-Marie

2010-01-01

300

A case analysis of the adoption of Internet applications by local sporting bodies in New Zealand  

Microsoft Academic Search

As a unique type of community-based organisation (CBO), local sporting clubs are typically run by volunteers who regularly carry out the playing, coaching and administrative roles that keep them functioning. Through a case study involving a New Zealand hockey association, this article examines the extent to which sporting clubs use Internet applications by examining their use of email (for communications),

Scott Bingley; Stephen Burgess

301

Winter Olympic Sports  

NSDL National Science Digital Library

Exploring Winter Olympic Sports Let's take a look at some of the different winter olympic sports Alpine Skiing Biathalon Bobsleigh Cross country Curling Figure Skating Freestyle skiing Ice Hockey Luge Nordic Combined Short track speed skating Skeleton Ski Jumping Snowboard Speed Skating ...

Keller, Mrs.

2010-01-23

302

Falling in love with a wheelchair: enabling\\/disabling technologies  

Microsoft Academic Search

The aim of this article was to explore how young women with physical impairments make use of technology in their identity construction, drawing on the metaphor of the cyborg as well as on science and technology studies and disability research. In addition to participant observation, semi-structural interviews were conducted and video diaries were kept of the women playing sledge hockey,

Elisabet Apelmo

2012-01-01

303

1998 Arthur Ashe Jr. Sports Scholars Awards.  

ERIC Educational Resources Information Center

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…

Chenoweth, Karin; Evelyn, Jamilah

1998-01-01

304

Exploring the Motives for Viewing Televised Sports.  

ERIC Educational Resources Information Center

A total of 286 subjects was presented with a series of motivations and asked to evaluate the relative importance of each in their exposure/avoidance decisions about watching sports programs on television. The 188 sports viewers assessed the importance of each motivation for their viewing of baseball, hockey, football, and tennis. The 98…

Gantz, Walter

305

Five Year Overview of Sport Injuries: The NAIRS Model.  

ERIC Educational Resources Information Center

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…

Buckley, William E.

1982-01-01

306

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

ERIC Educational Resources Information Center

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…

Fullinwider, Robert K.

2006-01-01

307

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

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…

Moriarty, Dick; And Others

308

Heat illness.  

PubMed

A 17-year-old girl collapsed during a field hockey practice on a hot August afternoon, apparently suffering from heat illness, which is responsible for about 5,000 deaths annually. A panel of experts explores this girl's case, discusses heat illness in general, and makes recommendations about diagnosis, prevention, and treatment. PMID:2398843

Buss, D D; Kelly, J M; Reinholtz, G D; Roberts, W O; Fischer, D A

1990-08-01

309

Ophthalmologic injuries.  

PubMed

The types of eye injuries that occur in various sports are discussed, with an emphasis on racquet sports and ice hockey. Both field management and treatment by a specialist are considered. Physicians should encourage players to wear polycarbonate or industrial safety-thickness lenses or protective face cages. PMID:6561679

Diamond, G R; Quinn, G E; Pashby, T J; Easterbrook, M

1984-03-01

310

An investigation into teaching games for understanding: effects on skill, knowledge, and game play.  

PubMed

The purpose of this study was to test the validity of the games for understanding model by comparing it to a technique approach to instruction and a control group. The technique method focused primarily on skill instruction where the skill taught initially was incorporated into a game at the end of each lesson. The games for understanding approach emphasized developing tactical awareness and decision making in small game situations. Two physical education specialists taught field hockey using these approaches for 15 lessons (45 min each). The control group did not receive any field hockey instruction. Data were collected from 71 middle school children. Pretests and posttests were administered for hockey knowledge, skill, and game performance. Separate analyses of variance or analyses of covariance were conducted to examine group differences for cognitive and skill outcomes. The games for understanding group scored significantly higher on passing decision making than the technique and control groups during posttest game play and significantly higher than the control group for declarative and procedural knowledge. The games for understanding group scored significantly higher on control and passing execution than the other groups during posttest game play. For hockey skill, there were no significant differences among the treatment groups for accuracy, but the technique group recorded faster times than the control group on the posttest. PMID:10522286

Turner, A P; Martinek, T J

1999-09-01

311

Fortuitously discovered persistent left superior vena cava in young competitive athletes. Clinical implications of sports physicians.  

PubMed

This report describes two athletes with persistent left superior vena cava (PLSVC) accidentally identified during preparticipation medical evaluation. The clinical implications of PLSVC for sports physicians are also discussed. A 16-year-old male ice hockey player and an 18-year-old male high-level field hockey player visited our institute for medical evaluation prior to participating in competition. Neither complained of palpitation, faintness or syncope, which would have suggested a possible cardiac rhythm disturbance, or had been informed of any abnormalities in previous physical examinations. Nonetheless, echocardiography revealed dilated coronary sinuses, and venography confirmed PLSVC and, in one case, showed the absence of the right superior vena cava. Electrocardiograms showed the field hockey player to have an ectopic atrial rhythm with left axis deviation of the frontal plane P-wave and the ice hockey player to have normal sinus rhythm. Symptom-limited treadmill testing revealed nothing abnormal, and after explaining the possible rhythm instability and the potential risk associated with cardiac surgery, the subjects were permitted full participation in competitive sports. Although information is scarce, available data on PLSVC suggest it is benign for competitive athletes. Nevertheless, complications arising from other cardiovascular anomalies, from potential cardiac rhythm disturbances, and from cardiac surgery necessitated by major injuries should be considered prior to participation in competitive sports. PMID:11447374

Kinoshita, N; Hasegawa, K; Oguma, Y; Katsukawa, F; Onishi, S; Yamazaki, H

2001-06-01

312

High impact blow detection over a reactive Mobile-Cloud Framework  

Microsoft Academic Search

Brain injury is quite common in athletes due to the frequent and high level of impact, especially in football and hockey. One of the most challenging problems faced by medical personnel responsible for the health care of athletes is the recognition and management of concussions (1, 2). With the advancements in sensor technology, medical imaging, mobile devices, wireless communications, and

Eric Luster; Hong Wu; Elodie Billionniere

2011-01-01

313

Through the looking glass: you can play against your own reflection  

Microsoft Academic Search

This interactive artwork overturns the commonsense assumption that a looking glass reflects the world in front of it. The worlds outside and inside the looking glass are not symmetric in our optical system. This feature allows you to play an air-hockey game against yourself reflected in the looking glass.

Yasuaki Kakehi; Takeshi Naemura

2005-01-01

314

Body Image Disturbance in Selected Groups of Men.  

ERIC Educational Resources Information Center

Examined satisfaction with body image in sample of 18 male college hockey players, 18 male college body builders, and 18 college students in a psychology class using measures of body image distortion and body image dissatisfaction. Found marked levels of distortion and dissatisfaction in body builders, but not in other two groups. (Author/ABL)

Loosemore, Douglas J.; And Others

1989-01-01

315

Internet-Accessible Scholarly Resources for the Humanities and Social Sciences.  

ERIC Educational Resources Information Center

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…

ACLS Newsletter, 1997

1997-01-01

316

Social Cognitive Correlates of Young Adult Sport Competitors' Sunscreen Use  

ERIC Educational Resources Information Center

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…

Berndt, Nadine C.; O'Riordan, David L.; Winkler, Elisabeth; McDermott, Liane; Spathonis, Kym; Owen, Neville

2011-01-01

317

Exercise-Induced Asthma  

MedlinePLUS

... may be more challenging, as can cold-weather endurance sports like cross-country skiing or ice hockey. But that doesn't mean your child can't participate in these sports if he or she truly enjoys them. In fact, many athletes with asthma have found that with proper training ...

318

Teaching Methods Effectiveness and the Acquisition of Psycho-Motor Skills.  

ERIC Educational Resources Information Center

An experimental study was conducted to discover the relative effectiveness of five different instructional strategies on the acquisition of four psycho-motor skills associated with four physical sports (continuous volleying in volleyball, zig-zag dribbling in field hockey, headstand in gymnastics, and sail long jump in athletics). The subjects…

Ikulayo, Philomena Bolaji

319

Creating Growth in New Markets: A Simultaneous Model of Firm Entry and Price  

Microsoft Academic Search

Sales in a new market generally follow a hockey-stick pattern: After commercial- ization, sales are very low for some time before there is a dramatic takeoff in growth. Reported sales takeoffs across products vary widely from a few years to several decades. Prior research identifies new firm entry or price declines as key factors that relate to the timing of

Barry L. Bayus; Wooseong Kang; Rajshree Agarwal

2007-01-01

320

Construct-a-Glove. Science by Design Series.  

ERIC Educational Resources Information Center

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…

Pulis, Lee

321

Lunar Influences on Human Aggression.  

ERIC Educational Resources Information Center

Used league records of all Canadian hockey games (N=426) played during a season to test a lunar-aggression hypothesis. Despite the use of multiple measures of lunar phase and interpersonal aggression, support for lunar influence was not forthcoming. Supplemental data revealed that beliefs in lunar influence are fairly common. (JAC)

Russell, Gordon W.; Dua, Manjula

1983-01-01

322

Lunar Cycles and Human Aggression: A Replication.  

ERIC Educational Resources Information Center

Tested lunar-aggression hypothesis using the aggressive penalties awarded in ice hockey over a season of competition. Interpersonal aggression was found to be unrelated to either the synodic or anomalistic cycles. Discussion centers on the persistence of lunar beliefs and their links to the literature on selective exposure and interpersonal…

Russell, Gordon W.; de Graaf, Jane P.

1985-01-01

323

76 FR 43259 - Foreign-Trade Zone 109-Watertown, NY, Application for Manufacturing Authority, North American...  

Federal Register 2010, 2011, 2012, 2013

...Authority, North American Tapes, LLC, (Textile Athletic Tape), Watertown, NY A request...tape (e.g., trainers, hockey) with textile backing material for the U.S. market...are woven cotton and polyester/cotton textile fabrics (duty rates: 10.5,...

2011-07-20

324

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

ERIC Educational Resources Information Center

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…

Schneider, Ray; Messenger, Steve

2012-01-01

325

Factors affecting the relative age effect in NHL athletes  

PubMed Central

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.

Parent-Harvey, Caroline I.; Desjardins, Christophe; Harvey, Edward J.

2014-01-01

326

Biography Today: Sports Series. Profiles of People of Interest to Young Readers. Volume 3, 1999.  

ERIC Educational Resources Information Center

This third volume is part of a series of biographies that profile individuals of interest to young people over the age of 9 years. The entries in this volume include Joe Dumars, basketball; Jim Harbaugh, football; Dominik Hasek, hockey; Michelle Kwan, figure skating; Rebecca Lobo, basketball; Greg Maddux, baseball; Fatuma Roba, marathon running;…

Harris, Laurie Lanzen, Ed.; Abbey, Cherie D., Ed.

327

Collision Lab  

NSDL National Science Digital Library

Use an air hockey table to investigate simple collisions in 1D and more complex collisions in 2D. Experiment with the number of discs, masses, and initial conditions. Vary the elasticity and see how the total momentum and kinetic energy changes during collisions.

Simulations, Phet I.; Dubson, Mike; Loeblein, Trish; Perkins, Kathy; Gratny, Mindy; Olson, Jon

2010-10-01

328

Plyometrics: A Legitimate Form of Power Training?  

ERIC Educational Resources Information Center

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)

Duda, Marty

1988-01-01

329

Free Fall  

NSDL National Science Digital Library

In this quick activity (page 1 of PDF), learners will use a simple physics of motion and gravity demonstration to test their predicting skills. Learners predict which quarter will hit the floor first during this free fall experiment. This activity not only requires learners to observe carefully, but also listen carefully! Relates to the linked video, DragonflyTV: Hockey.

Twin Cities Public Television, Inc.

2005-01-01

330

Leadership Development of Team Captains in Collegiate Varsity Athletics  

ERIC Educational Resources Information Center

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…

Grandzol, Christian; Perlis, Susan; Draina, Lois

2010-01-01

331

Sports for Life  

ERIC Educational Resources Information Center

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…

Schachter, Ron

2010-01-01

332

Individual differences in visual information processing rate and the prediction of performance differences in team sports: A preliminary investigation  

Microsoft Academic Search

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

J. J. Adam; R. B. Wilberg

1992-01-01

333

A Descriptive-Analytic Study of the Practice Field Behavior of a Winning Female Coach.  

ERIC Educational Resources Information Center

A winning collegiate field hockey coach was observed across seventeen practice sessions through one complete competitive season. A category system for the event recording of verbal and nonverbal behaviors delivered to the team and to the sixteen individual players produced descriptive-analytic information about relative behavior frequencies for…

Dodds, Patt; Rife, Frank

334

Moisture Outgassing Rates from TATB-Formulations: Experiments and Kinetic Model Development  

SciTech Connect

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.

Glascoe, E A; Dinh, L N; Small IV, W

2009-07-29

335

Intensity, repetitiveness, and directionality of habitual adolescent mobility patterns influence the tibial diaphysis morphology of athletes.  

PubMed

Mobility patterns affect the loads placed on the lower limbs during locomotion and may influence variation in lower limb diaphyseal robusticity and shape. This relationship commonly forms the basis for inferring mobility patterns from hominin fossil and skeletal remains. This study assesses the correspondence between athletic histories, varying by loading intensity, repetition and directionality, measured using a recall questionnaire, and peripheral quantitative computed tomography-derived measurements of tibial diaphysis rigidity and shape. Participants included male university varsity cross-country runners (n = 15), field hockey players (n = 15), and controls (n = 20) [mean age: 22.1 (SD +/- 2.6) years]. Measurements of tibial rigidity (including J, %CA, Imax, Imin, and average cortical thickness) of both runners and field hockey players were greater than controls (P < or = 0.05). Differences in tibial shape (Imax/Imin, P < or = 0.05) between runners and hockey players reflect pronounced maximum plane (Imax) rigidity in runners, and more symmetrical hypertrophy (Imax, Imin) among hockey players. This corresponds with the generally unidirectional locomotor patterns of runners, and the multidirectional patterns of hockey players. These results support the relationship between mobility and tibial diaphysis morphology as it is generally interpreted in the anthropological literature, with greater levels of mobility associated with increased diaphyseal robusticity and shape variation. Although exercise intensity may be the primary influence on these properties, the repetitiveness of the activity also deserves consideration. In conclusion, bone morphological patterns can reflect habitual behaviors, with adaptation to locomotor activities likely contributing to variation in tibial rigidity and shape properties in archaeological and fossil samples. PMID:19358289

Shaw, Colin N; Stock, Jay T

2009-09-01

336

Shock-wave initiation of heated plastified TATB detonation  

NASA Astrophysics Data System (ADS)

Explosive, plastified TATB, attracts attention with its weak sensitivity to shock loads and high temperature stability ( Pthreshold ? 6.5 GPa and Tcrit ? 250 0Q). However, at its cooling to T 250 0Q plastified TATB becomes as sensitive to shock load as octogen base HE: the excitation threshold reduces down to Pthreshold 2.0 GPa. The main physical reason for the HE sensitivity change is reduction in density at heating and, hence, higher porosity of the product (approximately from 2Moreover, increasing temperature increases the growth rate of uhotf spots which additionally increases the shock sensitivity [1]. Heated TATB experiments are also conducted at VNIIEF. The detonation excitation was computed within 1D program system MAG using EOS JWL for HE and EP and LLNL kinetics [1,2,3]. Early successful results of using this kinetics to predict detonation excitation in heated plastified TATB in VNIIEF experiments with short and long loading pulses are presented. Parameters of the chemical zone of the stationary detonation wave in plastified TATB (LX-17) were computed with the data from [1]. Parameters Heated In shell Cooled Unheated ?0 , g/cm3 1.70 1.81 1.84 1.905 D , km/s 7.982 7.764 7.686 7.517 PN, GPa 45.4 45.8 35.7 32.9 PJ, GPa 27.0 27.3 27.2 26.4 ?x , mm 0.504 0.843 1.041 2.912 ?t , ns 63.1 108.6 135.5 387.4 [1] Effect of Confinement and Thermal Cycling on the Shock Initiation of LX-17 P.A. Urtiew, C.M. Tarver, J.L. Maienschein, and W.C. Tao. LLNL. Combustion and Flame 105: 43-53 (1996) [2] C.M. Tarver, P.A. Urtiew and W.C. Tao (LLNL) Effects of tandem and colliding shock waves on initiation of triaminotrinitrobenzene. J.Appl. Phys. 78(5), September 1995 [3] Craig M. Tarver, John W. Kury and R. Don Breithaupt Detonation waves in triaminotrinitrobenzene J. Appl. Phys. 82(8) , 15 October 1997.

Kuzmitsky, Igor; Rudenko, Vladimir; Gatilov, Leonid; Koshelev, Alexandr

1999-06-01

337

Plutonium Immobilization Program cold pour tests  

SciTech Connect

The Plutonium Immobilization Program (PIP) is a joint venture between the Savannah River Site, Lawrence Livermore National Laboratory, Argonne National Laboratory, and Pacific Northwest National Laboratory to carry out the disposition of excess weapons-grade plutonium. This program uses the can-in-canister (CIC) approach. CIC involves encapsulating plutonium in ceramic forms (or pucks), placing the pucks in sealed stainless steel cans, placing the cans in long cylindrical magazines, latching the magazines to racks inside Defense Waste Processing Facility (DWPF) canisters, and filling the DWPF canisters with high-level waste glass. This process puts the plutonium in a stable form and makes it attractive for reuse. At present, the DWPF pours glass into empty canisters. In the CIC approach, the addition of a stainless steel rack, magazines, cans, and ceramic pucks to the canisters introduces a new set of design and operational challenges: All of the hardware installed in the canisters must maintain structural integrity at elevated (molten-glass) temperatures. This suggests that a robust design is needed. However, the amount of material added to the DWPF canister must be minimized to prevent premature glass cooling and excessive voiding caused by a large internal thermal mass. High metal temperatures, minimizing thermal mass, and glass flow paths are examples of the types of technical considerations of the equipment design process. To determine the effectiveness of the design in terms of structural integrity and glass-flow characteristics, full-scale testing will be conducted. A cold (nonradioactive) pour test program is planned to assist in the development and verification of a baseline design for the immobilization canister to be used in the PIP process. The baseline design resulting from the cold pour test program and CIC equipment development program will provide input to Title 1 design for second-stage immobilization. The cold pour tests will be conducted in two major phases during fiscal years 1999 and 2000.

Hovis, G.L.; Stokes, M.W.; Smith, M.E.; Wong, J.W.

1999-07-01

338

Ka- and W-band PM-HFET DRO's  

NASA Astrophysics Data System (ADS)

Dielectric resonator stabilized oscillators have been designed, fabricated, and investigated. The oscillators consist of microstrip matching and biasing circuits on alumina substrate, a dielectric resonator puck, and a low-noise quarter-micron InGaAs-GaAs pseudomorphic (PM) HFET as the active device. At 37 GHz and 81 GHz, output powers of 10 dBm and 0 dBm have been measured. The phase noise of the Ka-band and W-band oscillators has been determined to be -97 dBc/Hz at 100 kHz and -90 dBc/Hz at 1 MHz off carrier, respectively.

Wenger, J.; Guettich, U.

1993-06-01

339

Flight Experiments On Energy Scaling For In-Space Laser Propulsion  

SciTech Connect

As a preparatory study on space-borne laser propulsion, flight experiments with a parabolic thruster were carried out on an air cushion table. The thruster was mounted like a sail on a puck, allowing for laser-driven motion in three degrees of freedom (3 DOF) in artificial weightlessness. Momentum coupling is derived from point explosion theory for various parabolic thruster geometries with respect to energy scaling issues. The experimental data are compared with theoretical predictions and with results from vertical free flights. Experimental results for the air-breakdown threshold and POM ablation inside the thruster are compared with fluence data from beam propagation modeling.

Scharring, Stefan; Eckel, Hans-Albert [Institute of Technical Physics, German Aerospace Center, D-70569 Stuttgart, Pfaffenwaldring 38-40 (Germany); Wollenhaupt, Eric; Roeser, Hans-Peter [Institute of Space Systems, University of Stuttgart, D-70569 Stuttgart, Pfaffenwaldring 31 (Germany)

2010-05-06

340

CAD/CAM complete dentures: a review of two commercial fabrication systems.  

PubMed

The use of computer-aided design and computer-aided manufacturing (CAD/CAM) has become available for complete dentures through the AvaDent and Dentca systems. AvaDent uses laser scanning and computer technology. Teeth are arranged and bases formed using proprietary software.The bases are milled from prepolymerized pucks of resin. Dentca uses computer software to produce virtual maxillary and mandibular edentulous ridges, arrange the teeth and form bases. The dentures are fabricated using a conventional processing technique. PMID:23875432

Kattadiyil, Mathew T; Goodacre, Charles J; Baba, Nadim Z

2013-06-01

341

Color management and calibration techniques at the University of Arizona  

NASA Astrophysics Data System (ADS)

At the University of Arizona a research project is underway which addresses consistent color and gray-scale reproduction for digital color displays used in medical image interpretation. Now the University of Arizona can enter the field of ICC Profiling and Color Management. A color calibration facility was developed from ground up. Color calibration is presented for three color LCDs as is color accuracy. A PR670 Spectroradiometer was used to correct for errors of the pucks. A method was used to calculate the color accuracy and the ?E values.

Hashmi, Syed F.; Roehrig, Hans; Krupinski, Elizabeth A.

2011-09-01

342

Plutonium Immobilization Project - Can-In-Canister Hardware Development/Selection  

SciTech Connect

This paper covers the design, development and testing of the magazines (cylinders containing cans of plutonium-ceramic pucks) and the rack that holds them in place inside the waste glass canister. Several magazine and rack concepts were evaluated to produce a design that gives the optimal balance between resistance to thermal degradation and facilitation of remote handling. This paper also reviews the effort to develop a jointed robotic arm that can remotely load seven magazines into defined locations inside a stationary canister working only through the 4 inch (102mm) diameter canister throat.

Hamilton, L.

2001-02-15

343

Plutonium immobilization program - Cold pour Phase 1 test results  

SciTech Connect

The Plutonium Immobilization Project will disposition excess weapons grade plutonium. It uses the can-in-canister approach that involves placing plutonium-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) glass pour program was performed to develop and verify the baseline design for the canister and internal hardware. This paper describes the Phase 1 scoping test results.

Hamilton, L.

2000-04-28

344

Flight Experiments On Energy Scaling For In-Space Laser Propulsion  

NASA Astrophysics Data System (ADS)

As a preparatory study on space-borne laser propulsion, flight experiments with a parabolic thruster were carried out on an air cushion table. The thruster was mounted like a sail on a puck, allowing for laser-driven motion in three degrees of freedom (3 DOF) in artificial weightlessness. Momentum coupling is derived from point explosion theory for various parabolic thruster geometries with respect to energy scaling issues. The experimental data are compared with theoretical predictions and with results from vertical free flights. Experimental results for the air-breakdown threshold and POM ablation inside the thruster are compared with fluence data from beam propagation modeling.

Scharring, Stefan; Wollenhaupt, Eric; Eckel, Hans-Albert; Röser, Hans-Peter

2010-05-01

345

Magnetorheological finishing of a diamond turned poly(methylmethacrylate) flat  

NASA Astrophysics Data System (ADS)

Magnetorheological finishing (MRF) of a diamond turned poly(methymethacrylate) (PMMA) flat was demonstrated using a commercial Q22Y MRF machine and a zirconia-based magnetorheological (MR) fluid. The surface of a 38mm diameter by 7.6mm thick puck was processed in a sequence of two figure correction runs. The initial p-v wave front error of 4.5?m was reduced to 0.35 ?m, and the average rms surface micro-roughness was reduced from 3.8nm to 0.47nm. The diamond turning marks were eliminated.

DeGroote, Jessica E.; Jacobs, Stephen D.; Schoen, John M.; Romanofsky, Henry J.; Kozhinova, Irina A.

2003-05-01

346

Creep Testing Plastic-Bonded Explosives in Uni-axial Compression  

SciTech Connect

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.

Gagliardi, F J; Cunningham, B J

2008-03-13

347

Dynamic Characterization of Mock Explosive Material Using Reverse Taylor Impact Experiments  

SciTech Connect

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.

Ferranti, L; Gagliardi, F J; Cunningham, B J; Vandersall, K S

2010-03-25

348

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

SciTech Connect

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.

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

1994-07-05

349

Sequence diversity of the peptaibol antibiotic suzukacillin-A from the mold Trichoderma viride.  

PubMed

From the culture broth of the mold Trichoderma viride, strain 63 C-I, the polypeptide antibiotic suzukacillin (SZ) was isolated. A peptide mixture named SZ-A was obtained by crystallization from crude SZ. Individual peptides from SZ-A were isolated by semipreparative HPLC and sequences were determined by HPLC-ESI-MS. The data confirm a general sequence of SZ-A published previously and in addition establish the individual sequences of 15 acetylated eicosa peptides with C-terminal alcohols. The major peptide SZ-A4 (21% of all peptides) shows the sequence:Ac-Aib-Ala-Aib-Ala-Aib-Ala(6)-Gln-Aib-Lx(9)-Aib-Gly-Aib(12)-Aib-Pro-Vx(15)-Aib-Vx(17)-Gln-Gln-Fol. Amino acid exchanges of the peptaibol are located in position 6 (Ala/Aib), 9 (Vx/Lx), 12 (Aib/Lx), 17 (Aib/Vx) and possibly at position15 (Val/Iva) (uncommon abbreviations: Aib (alpha-aminoisobutyric acid); Iva (D-isovaline); Lx (L-leucine or L-isoleucine); Vx (L-valine or D-isovaline); Fol (L-phenylalaninol)). PMID:16245259

Krause, Corina; Kirschbaum, Jochen; Jung, Günther; Brückner, Hans

2006-05-01

350

Development of the Tactical Skills Inventory for Sports.  

PubMed

Purpose of this study, in which 19 trainers and 415 competitive youth field hockey and soccer players (M age=15.9, SD=1.6; 283 boys and 132 girls) selected by their age, sex, and performance status participated, was to develop a practical, reliable, and valid measure of tactical skills in sports. With trainers, 34 questions were formulated involving tactical skills. Factor analysis yielded the Tactical Skills Inventory for Sports. Scales were labeled Positioning and Deciding, Knowing about Ball Actions, Knowing about Others, and Acting in Changing Situations, covering all aspects of tactical skills regarding Declarative versus Procedural knowledge and Attack and Defense. Internal consistency and test-retest measures for reliability (except Knowing about Ball Actions) were within acceptable limits. Elite players scored better than nonelite players, supporting construct validity. The inventory is suitable for measuring tactical skills in youth field hockey and soccer players in sports practice. PMID:15648483

Elferink-Gemser, M T; Visscher, C; Richart, H; Lemmink, K A P M

2004-12-01

351

Catastrophic pediatric sports injuries.  

PubMed

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

Luckstead, Eugene F; Patel, Dilip R

2002-06-01

352

KSC-04PD-1317  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, Jay Feaster, general manager of the National Hockey League 2004 Champions Tampa Bay Lightning, displays the Stanley Cup. At right is KSC Deputy Director Woodrow Whitlow. The cup was also briefly available for viewing by employees in the KSC Training Auditorium. Feaster brought the cup to KSC while on a tour. The Stanley Cup weighs 35 pounds and is more than 100 years old. The Lightning will be added to the cup in September.

2004-01-01

353

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

PubMed Central

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.

Ebaugh, David

2010-01-01

354

Thermal storage HVAC system retrofit provides economical air conditioning  

Microsoft Academic Search

This article describes an EMS-controlled HVAC system that meets the ventilation and cooling needs of an 18,000-seat indoor ice hockey arena. The Buffalo Memorial Auditorium (affectionately referred to as the Aud) was built in 1937 under the Works Project Administration of the federal government. Its original configuration included a 12,000-seat arena with an ice skating rink. By the late 1980s,

1993-01-01

355

Solving the energy dilemma at Seven Bridges Ice Arena  

Microsoft Academic Search

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 ft² (11,215 m²) world class facility. The Olympic Hockey League ice rink has seating for 800 spectators; and

Louria

1996-01-01

356

Force-velocity relationship and maximal power on a cycle ergometer  

Microsoft Academic Search

Summary  The force-velocity relationship on a Monark ergometer and the vertical jump height have been studied in 152 subjects practicing\\u000a different athletic activities (sprint and endurance running, cycling on track and\\/or road, soccer, rugby, tennis and hockey)\\u000a at an average or an elite level. There was an approximatly linear relationship between braking force and peak velocity for\\u000a velocities between 100 and

H. Vandewalle; G. Peres; J. Heller; J. Panel; H. Monod

1987-01-01

357

Traumatic Brain Injury in High School Athletes  

Microsoft Academic Search

Results Of 23 566 reported injuries in the 10 sports during the 3-year study period, 1219 (5.5%) were MTBIs. Of the MTBIs, football accounted for 773 (63.4%) of cases; wrestling, 128 (10.5%); girls' soccer, 76 (6.2%); boys' soccer, 69 (5.7%); girls' bas- ketball, 63 (5.2%); boys' basketball, 51 (4.2%); softball, 25 (2.1%); baseball, 15 (1.2%); field hockey, 13 (1.1%); and

John W. Powell; Kim D. Barber-Foss

1999-01-01

358

Exploratorium: Sport Science  

NSDL National Science Digital Library

Looking at the processes and actions embedded within various team and individual sports is a great way to get exposed to concepts and ideas from physics, engineering, and any other number of basic and applied sciences. The Exploratorium Museum in San Francisco has developed this remarkable site that brings together interactive exhibits, activities, and video clips on the world of sport science. The materials here are organized primarily by sport. The site includes areas on skateboarding, baseball, hockey and other activities.

359

The Relationships Among Three Components of Perceived Risk of Injury, Previous Injuries and Gender in Contact Sport Athletes  

Microsoft Academic Search

This study examined the relationships among three components of perceived risk of injury: (a) probability of injury, (b) worry\\/concern of being injured, and (c) confidence in avoiding injury. Participants were 434 athletes from 3 contact sports (hockey, soccer, and football). Correlations between the components showed a positive relationship between worry\\/concern and probability of injury, and negative relationships between worry\\/concern and

Sandra E. Short; Jennifer Reuter; Jerel Brandt; Martin W. Short; Anthony P. Kontos

360

Nutrition Science and the Winter Olympics  

NSDL National Science Digital Library

Science is a powerful asset for athletes who want to use nutrition to their advantage. Whether an Olympic medal is won by tenths of a second in a ski race, decimal points in a figure skating competition, or goals in an ice hockey game, an athlete's nutritional status makes a critical difference in reaching peak performance.This course explores the science of sports nutrition and shows how to apply nutrition principles to benefit an athlete's training and performance.

361

Bridge Building  

NSDL National Science Digital Library

This is a quick activity (on page 2 of the PDF) about how the arrangement of carbon atoms determines carbon's different properties. Learners will build bridges with Post-It notes that model two types of carbon molecules, graphite and carbon nanotubes, and test which structure of the same material can bear the weight of the most pennies. Also relates to linked video, DragonflyTV Nano: Hockey Sticks.

Twin Cities Public Television, Inc.

2008-01-01

362

Sport-Specific Practice and the Development of Expert Decision-Making in Team Ball Sports  

Microsoft Academic Search

The role of sport-specific practice in the development of decision-making expertise in the sports of field hockey, netball, and basketball was examined. Fifteen expert decision-makers and 13 experienced non-expert athletes provided detailed information about the quantity and type of sport-specific and other related practice activities they had undertaken throughout their careers. Experts accumulated more hours of sport-specific practice from the

Joseph Baker; Jeane Cote; Bruce Abernethy

2003-01-01

363

Sprint acceleration performance in team sports : biomechanical characteristics and training methods  

Microsoft Academic Search

Sprinting is a fundamental activity in many team sports such as soccer, rugby, football, field hockey, and basketball. Specifically, the ability to rapidly increase sprint running velocity over short distances, which is often referrcd to as sprint acceleration ability, is of major importance to team-sport athletes since sprint efforts during team-sport matches are typically of short duration (e.g., 10-20 m,

Naoki Kawamori

2008-01-01

364

Physical efficiency tests on Indian male "Kabaddi" inter-university players.  

PubMed Central

The participants of inter-university "Kabaddi" competition showed higher values of height, weight and surface area than average Indian population, indicating better attainment of growth in them. Further, the values of respiratory efficiency tests like, FEV1, MEFR and PEFR were also observed to be more in these players, probably due to training effect. The grip strength values were high in comparison to those of Indian football goalkeepers and hockey players. Images p33-a

De, A. K.; Dasgupta, P. K.; Panda, B. K.; Bhattacharya, A. K.

1982-01-01

365

Ground-based high resolution observations of the Uranian system in the near IR.  

NASA Astrophysics Data System (ADS)

The system of Uranus has been observed in May 1999 by means of the adonis/SHARPII+ Adaptive Optics system implemented on the 3.6 m telescope of La Silla-ESO (Chile). The use of the Shack-Hartmann wavefront sensor on the planet itself and the excellent seeing conditions have permitted to reach an angular resolution of ~ 0.14'' in the H broad band (1.6mu m). The sharpness of the images has been subsequently restored using a new myopic deconvolution method (MAP) including a specific edge preserving object prior. The images have revealed the presence of a latitudinal structure of the atmospheric clouds on the planetary disk (J and H bands), the presence of the Epsilon ring and its longitudinal anomaly.The most internal rings (Delta, Gamma, Eta) are also visible after deconvolution. Three of the known satellites has been detected: Ariel, Miranda and Puck (discovered by Voyager in 1989). We detect a significant shift of Puck's position with respect to the expected position, derived from the NASA/JPL Ephemeris Generator. We also present photometry of the 3 satellites and of the ring Epsilon using the J, H, K filters.

Marchis, F.; Berthier, J.; Descamps, P.; Fusco, T.; Prange, R.; Sekiguchi, T.

1999-09-01

366

Geology of the Uranian satellites  

NASA Astrophysics Data System (ADS)

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.

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

367

Rings and Satellites of Uranus: Colorful and Not So Dark  

NASA Astrophysics Data System (ADS)

Photometric properties of nine uranian satellites and four rings, based on six Hubble Space Telescope images taken in 1995, are presented. Derived albedos are consistent with previous data taken at the same phase angle of 1°, but inconsistent with most Voyager-based estimates extrapolated from observations at phase angles above 15°. The shape of phase functions in the range 1-90° is similar to that of asteroids. Darker surfaces have steeper phase functions than brighter ones, except for the four brightest satellites, which have the same phase function. Puck's geometric albedo in the visible is 0.11 ± 0.015, much larger than the Voyager-based value of 0.074 ± 0.008. The satellites smaller than Puck may be 10% larger than Voyager-based estimates. Ring particles have a geometric albedo of 0.061 ± 0.006, much larger than the Voyager-based value of 0.032 ± 0.003. The longitudinal variation of brightness of the ? ring indicates that the mean separation of particles in the ring is four to five times their diameter. While the uranian rings and satellites seemed to be all gray heretofore, the wide wavelength range of this study, 340-910 nm, detected their subtle, distinct colors. Rings and the minor satellites are brown, Miranda is blue, Umbriel is red, and Ariel, Titania, and Oberon are yellow. Rings and minor satellites belong spectrally to M-type asteroids.

Karkoschka, Erich

1997-02-01

368

WRAP low level waste (LLW) glovebox operational test report  

SciTech Connect

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.

Kersten, J.K.

1998-02-19

369

Molecular Adsorber Coating  

NASA Technical Reports Server (NTRS)

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.

Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory

2011-01-01

370

Plutonium Immobilization Project - Can-In-Canister Hardware Development/Selection  

SciTech Connect

The Plutonium Immobilization Project (PIP) is a program funded by the U.S. Department of Energy to develop technology to disposition excess weapons grade plutonium. This program introduces the ''Can-in-Canister'' (CIC) technology that immobilizes the plutonium by encapsulating it in ceramic forms (or pucks) and ultimately surrounding it with high-level waste glass to provide a deterrent to recovery. Since there are significant radiation, contamination and security concerns, the project team is developing unique technologies to remotely perform plutonium immobilization tasks. This paper covers the design, development and testing of the magazines (cylinders containing cans of ceramic pucks) and the rack that holds them in place inside the waste glass canister. Several magazine and rack concepts were evaluated to produce a design that gives the optimal balance between resistance to thermal degradation and facilitation of remote handling. This paper also reviews the effort to develop a join ted arm robot that can remotely load seven magazines into defined locations inside a stationary canister working only through the 4 inch (102 mm) diameter canister throat.

Hamilton, L.

2001-01-05

371

Plutonium Immobilization Project - Can-In-Canister Hardware Development/Selection  

SciTech Connect

The Plutonium Immobilization Project (PIP) is a program funded by the U.S. Department of Energy to develop technology to disposition excess weapons grade plutonium. This program introduces the ''Can-in-Canister'' (CIC) technology that immobilizes the plutonium by encapsulating it in ceramic forms (or pucks) and ultimately surrounding it with high-level waste glass to provide a deterrent to recovery. Since there are significant radiation, contamination and security concerns, the project team is developing unique technologies to remotely perform plutonium immobilization tasks. This paper covers the design, development and testing of the magazines (cylinders containing cans of ceramic pucks) and the rack that holds them in place inside the waste glass canister. Several magazine and rack concepts were evaluated to produce a design that gives the optimal balance between resistance to thermal degradation and facilitation of remote handling. This paper also reviews the effort to develop a jointed arm robot that can remotely load seven magazines into defined locations inside a stationary canister working only through the 4 inch (102 mm) diameter canister throat.

Hamilton, L.

2001-01-10

372

The Plutonium Transition from Nuclear Weapons to Crypt  

SciTech Connect

With the end of the ''Cold War'' thousands of nuclear warheads are being dismantled. The National Academy of Sciences termed this growing stockpile of plutonium and highly enriched uranium ''a clear and present danger'' to international security. DOE/MD selected a duel approach to plutonium disposition--burning MOX fuel in existing reactors and immobilization in a ceramic matrix surrounded by HLW glass. MOX material will be pits and clean metal. The challenges come with materials that will be transferred to Immobilization--these range from engineered materials to residues containing < 30% Pu. Impurity knowledge range from guesses to actual data. During packaging, sites will flag ''out of the ordinary'' containers for characterized. If the process history is lost, characterization cost will escalate rapidly. After two step blending and ceramic precursor addition, cold press and sintering will form 0.5-kg ceramic pucks containing {le}50 g Pu. Pucks will be sealed in cans, placed into magazines, then into HLW canisters; these canisters will be filled with HLW glass prior to being transported to the HLW repository. The Immobilization Program must interface with DP, EM, RW, and NN. Overlaid on top of these interfaces are the negotiations with the Russians.

Gray, L.W.

2000-03-14

373

Concussion Management, Education, and Return-to-Play Policies in High Schools  

PubMed Central

Background: Concussions represent 8.9% to 13.2% of all high school athletic injuries. How these injuries are managed is currently unknown. Hypothesis: There are differences in concussion management and awareness among boys football, boys ice hockey, and boys and girls soccer. Study Design: Descriptive epidemiologic study. Methods: High school athletic directors were contacted via e-mail and asked to complete, and request that their staff complete, an online survey with 4 sections aimed at athletic directors, head coaches, team physicians, and certified athletic trainers. Results: According to coaches, concussion awareness education was provided for football (97%), hockey (65%), and boys and girls soccer (57% and 47%, respectively) (P < 0.01). Use of sideline screening tools was significantly greater for football (P = 0.03). All participants agreed that a player who has suffered a concussion cannot return to play the same day. Conclusion: There is a difference in concussion management and awareness among the 4 sports. Concussion education is well promoted in football but should be expanded in soccer and hockey. Players are not allowed to return to play the same day, and the majority are referred to a physician. Clinical Relevance: Study results highlight the differences in concussion education among sports. Health care providers should address these gaps.

Esquivel, Amanda; Haque, Sadiq; Keating, Patrick; Marsh, Stephanie; Lemos, Stephen

2013-01-01

374

Recent advances in the molten salt technology for the destruction of energetic materials  

SciTech Connect

The DOE has thousands of pounds of energetic materials which result from dismantlement operations at the Pantex Plant. The authors have demonstrated the Molten Salt Destruction (MSD) Process for the treatment of explosives and explosive-containing wastes on a 1.5 kilogram of explosive per hour scale and are currently building a 5 kilogram per hour unit. MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen and water. Any inorganic constituents of the waste, such as binders and metallic particles, are retained in the molten salt. The destruction of energetic material waste is accomplished by introducing it, together with air, into a crucible containing a molten salt, in this case a eutectic mixture of Na, K, and Li carbonates. The following pure component DOE and DoD explosives have been destroyed in LLNL`s experimental unit at their High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K-6, NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following formulations were also destroyed: Comp B, LX-10, LX-16, LX-17, PBX-9404, and XM46, a US Army liquid gun propellant. In this 1.5 kg/hr unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NOx were found to be well below 1T. In addition to destroying explosive powders and molding powders the authors have also destroyed materials that are typical of real world wastes. These include shavings from machined pressed parts of plastic bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the information obtained on the smaller unit, the authors have constructed a 5 kg/hr MSD unit, incorporating LLNL`s advanced chimney design. This unit is currently under shakedown tests and evaluation.

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

1995-11-01

375

Kinetic Modeling of Slow Energy Release in Non-Ideal Carbon Rich Explosives  

SciTech Connect

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.

Vitello, P; Fried, L; Glaesemann, K; Souers, C

2006-06-20

376

High-Temperature Transport Properties of Yb4- x Sm x Sb3  

NASA Astrophysics Data System (ADS)

Polycrystalline L4Sb3 (L = La, Ce, Sm, and Yb) and Yb4- x Sm x Sb3, which crystallizes in the anti-Th3P4 structure type ( I-43d no. 220), were synthesized via high-temperature reaction. Structural and chemical characterization were performed by x-ray diffraction and electronic microscopy with energy-dispersive x-ray analysis. Pucks were densified by spark plasma sintering. Transport property measurements showed that these compounds are n-type with low Seebeck coefficients, except for Yb4Sb3, which shows semimetallic behavior with hole conduction above 523 K. By partially substituting Yb by a trivalent rare earth we successfully improved the thermoelectric figure of merit of Yb4Sb3 up to 0.7 at 1273 K.

Chamoire, A.; Gascoin, F.; Estournès, C.; Caillat, T.; Tédenac, J.-C.

2010-09-01

377

Spectrophotometry of Inner Satellites of Uranus  

NASA Astrophysics Data System (ADS)

We propose spectrophotometry with the FOS/Red of the innerUranian satellites Puck, Portia, and Juliet, which areimpossible to observe from the ground. Small apertures willbe used for accurate measurements of the scattered light fromUranus, and we expect to get good spectra over the wavelengthrange 0.28 to 0.80 microns. We will also obtain a high-quality spectrum of Miranda to wavelengths as short as 0.22microns. The results will be interpreted with reference toknown reflectance spectra for similar objects including C- andD-type asteroids, satellites and rings of outer planets, andlaboratory spectra of dark carbon-bearing compounds. Thisprograms follows our successful recovery of eight innersatellites of Uranus with the Planetary Camera in HST Cycle 4.

Zellner, Benjamin

1996-07-01

378

Linear Synchronous Motor Repeatability Tests  

SciTech Connect

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.

Ward, C.R.

2002-10-18

379

The design, magnetization and control of a superconducting permanent magnet synchronous motor  

NASA Astrophysics Data System (ADS)

This paper describes in detail the method of magnetization of a superconducting permanent magnet synchronous motor. The rotor of the motor consists of 60 superconducting pucks, which are magnetized by two additional copper windings. The pulse field magnetization (PFM) method is considered and the resulted distribution of the magnetizing flux linkage from the rotor is not a perfect sine wave in the air gap, which leads to a large torque ripple and harmonics of the stator currents. In order to suppress the torque ripple, an iterative learning control (ILC) algorithm is used in addition to the former field-oriented control method. The results show the ILC algorithm can largely reduce the torque ripple.

Jiang, Y.; Pei, R.; Xian, W.; Hong, Z.; Coombs, T. A.

2008-06-01

380

Development and Testing of Molecular Adsorber Coatings  

NASA Technical Reports Server (NTRS)

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.

Abraham, Nithin; Hasegawa, Mark; Straka, Sharon

2012-01-01

381

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

NASA Astrophysics Data System (ADS)

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.

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

2011-11-01

382

Nonlinear Stability of Triangular Equilibrium Point in the Generalized Photogravitational Chermnykh-Like Problem  

NASA Astrophysics Data System (ADS)

In 2006, an outer ring-moon system composed by the satellites Portia, Rosalind, Puck, and Mab, and two tenuous rings µ and ?, was discovered around Uranus by Showalter Lissauer (2006). We present the results of numerical simulations of an ensemble of micrometric particles of both rings disturbed by a combination of the solar radiation pressure force, the gravitational interaction with the satellites, and the planetary gravity modified by the oblateness. Our results show that the Poynting-Robertson drag component alone is responsible for a de-crease of the semimajor axis in a time scale of 105 to 106 years. In a shorter time scale, the oscillation of the eccentricity, caused by the radiation pressure component, is much more im-portant to the orbital evolution of the particle, even though the amplitude of oscillation is mitigated by the inclusion of the planetary oblateness. The combination of these effects with the gravitational interaction of the satellites result in close encounters between the particles and the satellites, leading the particles to move inward and outward within the ring region, and eventually colliding with the satellites. The percentage of collisions varies between 12% and 94% according to the size of the particle. All collisions with Puck, Portia and Rosalind have the value of impact velocity comparable to the escape velocity, which the most likely result is the deposition of material onto the surface of the satellite. In the other hand, the impact velocity with Mab exceeds the scape velocity of the satellite, so these collisions are energetic enough to eject material and supply material to the µ ring. This mechanics of dust production can also be applied to collisions with macroscopic bodies that my inhabit within the µ and ? rings.

Singh Kushvah, Badam

383

Development and testing of molecular adsorber coatings  

NASA Astrophysics Data System (ADS)

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.

Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

2012-10-01

384

Effects of bright light treatment on psychomotor speed in athletes.  

PubMed

Purpose: A recent study suggests that transcranial brain targeted light treatment via ear canals may have physiological effects on brain function studied by functional magnetic resonance imaging (fMRI) techniques in humans. We tested the hypothesis that bright light treatment could improve psychomotor speed in professional ice hockey players. Methods: Psychomotor speed tests with audio and visual warning signals were administered to a Finnish National Ice Hockey League team before and after 24 days of transcranial bright light or sham treatment. The treatments were given during seasonal darkness in the Oulu region (latitude 65 degrees north) when the strain on the players was also very high (10 matches during 24 days). A daily 12-min dose of bright light or sham (n = 11 for both) treatment was given every morning between 8 and 12 am at home with a transcranial bright light device. Mean reaction time and motor time were analyzed separately for both psychomotor tests. Analysis of variance for repeated measures adjusted for age was performed. Results: Time × group interaction for motor time with a visual warning signal was p = 0.024 after adjustment for age. In Bonferroni post-hoc analysis, motor time with a visual warning signal decreased in the bright light treatment group from 127 ± 43 to 94 ± 26 ms (p = 0.024) but did not change significantly in the sham group 121 ± 23 vs. 110 ± 32 ms (p = 0.308). Reaction time with a visual signal did not change in either group. Reaction or motor time with an audio warning signal did not change in either the treatment or sham group. Conclusion: Psychomotor speed, particularly motor time with a visual warning signal, improves after transcranial bright light treatment in professional ice-hockey players during the competition season in the dark time of the year. PMID:24860513

Tulppo, Mikko P; Jurvelin, Heidi; Roivainen, Eka; Nissilä, Juuso; Hautala, Arto J; Kiviniemi, Antti M; Kiviniemi, Vesa J; Takala, Timo

2014-01-01

385

Comparison of Recent Modeled and Observed Trends in Total Column Ozone  

NASA Technical Reports Server (NTRS)

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.

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

386

Effects of bright light treatment on psychomotor speed in athletes  

PubMed Central

Purpose: A recent study suggests that transcranial brain targeted light treatment via ear canals may have physiological effects on brain function studied by functional magnetic resonance imaging (fMRI) techniques in humans. We tested the hypothesis that bright light treatment could improve psychomotor speed in professional ice hockey players. Methods: Psychomotor speed tests with audio and visual warning signals were administered to a Finnish National Ice Hockey League team before and after 24 days of transcranial bright light or sham treatment. The treatments were given during seasonal darkness in the Oulu region (latitude 65 degrees north) when the strain on the players was also very high (10 matches during 24 days). A daily 12-min dose of bright light or sham (n = 11 for both) treatment was given every morning between 8 and 12 am at home with a transcranial bright light device. Mean reaction time and motor time were analyzed separately for both psychomotor tests. Analysis of variance for repeated measures adjusted for age was performed. Results: Time × group interaction for motor time with a visual warning signal was p = 0.024 after adjustment for age. In Bonferroni post-hoc analysis, motor time with a visual warning signal decreased in the bright light treatment group from 127 ± 43 to 94 ± 26 ms (p = 0.024) but did not change significantly in the sham group 121 ± 23 vs. 110 ± 32 ms (p = 0.308). Reaction time with a visual signal did not change in either group. Reaction or motor time with an audio warning signal did not change in either the treatment or sham group. Conclusion: Psychomotor speed, particularly motor time with a visual warning signal, improves after transcranial bright light treatment in professional ice-hockey players during the competition season in the dark time of the year.

Tulppo, Mikko P.; Jurvelin, Heidi; Roivainen, Eka; Nissila, Juuso; Hautala, Arto J.; Kiviniemi, Antti M.; Kiviniemi, Vesa J.; Takala, Timo

2014-01-01

387

KSC-04PD-1316  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, Mike Bolt holds the Stanley Cup, won this year by the National Hockey Leagues Tampa Bay Lightning. Bolt is the Stanley Cup keeper. The cup was also briefly available for viewing by employees in the KSC Training Auditorium. Jay Feaster, general manager of the Tampa Bay Lightning, brought the cup to KSC while on a tour. The Stanley Cup weighs 35 pounds and is more than 100 years old. The Lightning will be added to the cup in September.

2004-01-01

388

KSC-04PD-1315  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. Jack Legere, NASA Quality Assurance specialist for the Shuttle Program, displays the Stanley Cup to employees in the Orbiter Processing Facility. Behind him is Discovery. Jay Feaster, general manager of the National Hockey League 2004 Champions Tampa Bay Lightning, brought the cup to KSC while on a tour. The cup was also briefly available for viewing by employees in the KSC Training Auditorium. The Stanley Cup weighs 35 pounds and is more than 100 years old. The Lightning will be added to the cup in September.

2004-01-01

389

KSC-04PD-1318  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, Jay Feaster, general manager of the National Hockey League 2004 Champions Tampa Bay Lightning, sits next to the Stanley Cup in front of the open hatch into Discovery. The cup was also briefly available for viewing by employees in the KSC Training Auditorium. Feaster brought the cup to KSC while on a tour. The Stanley Cup weighs 35 pounds and is more than 100 years old. The Lightning will be added to the cup in September.

2004-01-01

390

KSC-04PD-1314  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. Jay Feaster, general manager of the National Hockey League 2004 Champions Tampa Bay Lightning, stands next to the Stanley Cup, which he brought to KSC while on a tour. The cup stands next to the orbiter Discovery in the Orbiter Processing Facility. The cup was also briefly available for viewing by employees in the KSC Training Auditorium. The Stanley Cup weighs 35 pounds and is more than 100 years old. The Lightning will be added to the cup in September.

2004-01-01

391

Traumatic Laryngeal Fracture in a Collegiate Basketball Player  

PubMed Central

Laryngotracheal trauma is a rare condition that accounts for less than 1% of blunt trauma. Laryngotracheal fractures are uncommon in sports, even in settings where athletes are more vulnerable, including football, basketball, and hockey. If a laryngeal injury is suspected, immediate evaluation is required to avoid a delay in the diagnosis of a potentially life-threatening injury. A collegiate basketball player sustained an unusual fracture involving the cricoid and thyroid cartilage during practice. This case illustrates the importance of rapid identification and early management of patients with blunt laryngotracheal trauma in sports.

Kim, Jeffery D.; Shuler, Franklin D.; Mo, Bi; Gibbs, Scott R.; Belmaggio, Tom; Giangarra, Charles E.

2013-01-01

392

Slapshot Science!  

NSDL National Science Digital Library

The following resource is fromLessonopoly, which has created student activities and lesson plans to support the video series, Science of the Olympic Winter Games, created by NBC Learn and the National Science Foundation. Featuring exclusive footage from NBC Sports and contributions from Olympic athletes and NSF scientists, the series will help teach your students valuable scientific concepts. In this particular lesson, students will learn about the slapshot, which is the fastest, hardest shot in ice hockey. Students will investigate elastic collisions, energy transfer and momentum exchange and will conduct an experiment which simulates making a slapshot.

2010-01-01

393

Momentum And The Physics Of A Slapshot  

NSDL National Science Digital Library

The following resource is fromLessonopoly, which has created student activities and lesson plans to support the video series, Science of the Olympic Winter Games, created by NBC Learn and the National Science Foundation. Featuring exclusive footage from NBC Sports and contributions from Olympic athletes and NSF scientists, the series will help teach your students valuable scientific concepts. In this particular lesson, students will begin this lesson by investigating a fun and memorable elastic collision. After watching the NBC Learn Video, Slap Shot Physics: Hockey, they will use dynamics carts (or skateboards) to investigate and develop a conceptual understanding of the conservation of momentum.

2010-01-01

394

Composite Materials  

NSDL National Science Digital Library

This is an activity (located on page 3 of PDF) about composites, materials made of 2 or more different components. Learners will be challenged to build the best mud bricks, one of the earliest examples of composites. From a supply of various building components, which the learners will examine for their different properties, they will build mud bricks, then dry them and put them through several tests. *Bricks must bake in the sun for 2-3 days prior to testing. Resource contains information about how this activity relates to carbon nanotubes and links to video, DragonflyTV Nano: Hockey Sticks.

Twin Cities Public Television, Inc.

2008-01-01

395

"Fever in the Hand"  

PubMed

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

Silber

1996-10-01

396

Major international sport profiles.  

PubMed

Sports are part of the sociocultural fabric of all countries. Although different sports have their origins in different countries, many sports are now played worldwide. International sporting events bring athletes of many cultures together and provide the opportunity not only for athletic competition but also for sociocultural exchange and understanding among people. This article reviews five major sports with international appeal and participation: cricket, martial arts, field hockey, soccer, and tennis. For each sport, the major aspects of physiological and biomechanical demands, injuries, and prevention strategies are reviewed. PMID:12296532

Patel, Dilip R; Stier, Bernhard; Luckstead, Eugene F

2002-08-01

397

Syndesmosis injuries of the ankle.  

PubMed

Ankle syndesmosis injuries are relatively frequent in sports, especially skiing, ice hockey, and soccer, accounting for 1 %-18 % of all ankle sprains. The evolution is unpredictable: When missed, repeated episodes of ankle instability may predispose to early degenerative changes, and frank osteoarthritis may ensue. Diagnosis is clinical and radiological, but arthroscopy may provide a definitive response, allowing one to address secondary injuries to bone and cartilage. Obvious diastasis needs to be reduced and fixed operatively, whereas less severe injuries are controversial. Nonoperative treatment may be beneficial, but it entails long rehabilitation. In professional athletes, more aggressive surgical treatment is warranted. PMID:23943273

Del Buono, Angelo; Florio, Antonietta; Boccanera, Michele Simone; Maffulli, Nicola

2013-12-01

398

Effect of heavy training in contact sports on MRI findings in the pubic region of asymptomatic competitive athletes compared with non-athlete controls  

Microsoft Academic Search

Objective  Bone marrow edema (BME) at the pubic symphysis on magnetic resonance imaging (MRI) is usually associated with groin pain and\\u000a stress injury of the pubic bone. Little is known of the pubic MR imaging findings of asymptomatic heavy training athletes\\u000a in contact sports.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  Pelvic MRI of male asymptomatic soccer (n?=?10), ice hockey (n?=?10), bandy (n?=?10) and female floor-ball

Hannu Paajanen; Heikki Hermunen; Jari Karonen

2011-01-01

399

Developmental changes and predictability of static strength in individuals of different maturity: a 30-year longitudinal study.  

PubMed

This longitudinal study analyses the development and predictability of static strength and their interactions with maturation in youth. Of 515 children followed annually from age 6 to 18 years, 59 males and 60 females were measured again at age 35. Early, average, and late maturity groups were established. Body height and mass were assessed. Static strength was measured using handgrip dynamometry. Pearson correlations were used as tracking coefficients. From 6 to 12 years of age, no static strength differences were found to exist between the maturity groups of both sexes. Static strength is significantly higher in early than in average and late maturing boys (age 13-16). In girls, a dose-response effect exists (age 11-14). Adult static strength predictability is low in early maturing boys and late maturing girls. It is moderate to high (50-76%) in the other maturity groups up to age 14. Predictors for adult static strength are childhood and adolescent handgrip dynamometry (in females only), medicine ball throw, sit-up, hockey ball throw, and 25-m sprint. Handgrip is a fair predictor of adult static strength at most ages in early and average maturing females; in average maturing males, it is a predictor at age 11. Other indicators of strength (e.g. hockey ball throw) are predictors in males. PMID:19437306

Taeymans, Jan; Clarys, Peter; Abidi, Hassane; Hebbelinck, Marcel; Duquet, William

2009-06-01

400

Acute aerobic exercise and information processing: modulation of executive control in a Random Number Generation task.  

PubMed

The immediate and short-term aftereffects of a bout of aerobic exercise on young adults' executive functions were assessed. Sixteen participants performed a Random Number Generation (RNG) task, which measured two aspects of executive function, before, during, and after ergometer cycling exercise. In a separate session, participants completed the same sequence of testing while seated on an ergometer without pedaling. Results suggest that aerobic exercise: (1) selectively influences RNG indices related to the ability to alternate ascending and descending runs throughout the entire exercise bout; (2) induces a shift to a less effortful number generation strategy, particularly during the first few minutes of the exercise; and (3) has no significant influence on RNG performance as soon as the exercise terminates. The strategic adjustments observed during the exercise are interpreted in the framework of Hockey's [Hockey, G. R. J. (1997). Compensatory control in the regulation of human performance under stress and high workload: A cognitive-energetical framework. Biological Psychology, 45, 73-93.] compensatory control model and suggest that concurrent effortful processes induced by cycling exercise may draw upon available attention resources and influence executive processing. PMID:19632661

Audiffren, Michel; Tomporowski, Phillip D; Zagrodnik, James

2009-09-01

401

Physiological responses to emotional excitement in healthy subjects and patients with coronary artery disease.  

PubMed

Emotional excitement may trigger cardiovascular (CV) events, particularly in patients with coronary artery disease (CAD). Our aim was to compare changes in various biomarkers in CAD patients and age-matched healthy male subjects during "real-life" emotional excitement. Enthusiastic male ice hockey spectators (CAD n = 18, healthy subjects n = 16) attended Finnish national ice hockey play-off matches. Heart rate variability, plasma catecholamines, endothelin-1 (ET-1) and interleukin-6 (IL-6) were determined at the baseline and during the match. A significantly more marked increase in both ET-1 and IL-6 was observed in CAD patients compared with healthy subjects during the match (time × group interaction p = 0.009 and p = 0.018 for ET-1 and IL-6, respectively). The high-frequency power of R-R intervals decreased in CAD patients (p<0.001) but did not change in healthy subjects (p = ns, time × group interaction p<0.001). Changes in adrenaline and noradrenaline did not differ between the groups. Emotional excitement causes more marked increases of markers of vasoconstriction and acute inflammation and withdrawal of cardiac vagal regulation in patients with CAD. PMID:23916871

Piira, Olli-Pekka; Miettinen, Johanna A; Hautala, Arto J; Huikuri, Heikki V; Tulppo, Mikko P

2013-10-01

402

Meeting People Where They Are: Connecting Climate Change Impacts with the Interests of Particular Communities  

NASA Astrophysics Data System (ADS)

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.

Wake, C. P.; Rogers, W. C.

2011-12-01

403

Parental attitudes toward mouthguards.  

PubMed

An 11-item, one-page questionnaire was mailed to 1800 parents chosen at random in the Henrico County, VA public school system. Parents were asked questions such as "who should be responsible for mouthguard wear?" "what sports should require mouthguards?" and "has [their] child ever sustained an oral or facial injury?" The parental responses indicate that mouthguard enforcement is the responsibility of both parents and coaches. Of the total injuries reported, 19% were sustained in basketball, 17% in baseball, and 11% in soccer. Despite these high injury rates, however, there was a lack of perceived need for mouthguard use in these sports. When asked which sports should require a mouthguard rule, the sports that generated the most responses were, in decreasing order, football, boxing, ice hockey, wrestling, field hockey, and karate. Parents were more likely to require mouthguards for their sons than daughters, and more likely to require them for their children who participated in a mandatory mouthguard sport, a contact sport, or who had been previously injured. The authors conclude that because parents view themselves as equally responsible as coaches for maintaining mouthguard use, both groups should be targeted and approached as a possible source for the recommendation of mandatory mouthguard rules in basketball, baseball, and soccer. PMID:9442537

Diab, N; Mourino, A P

1997-01-01

404

Diminished acquired equivalence yet good discrimination performance in older participants.  

PubMed

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

Robinson, Jasper; Owens, Emma

2013-01-01

405

Recent advances in the molten salt destruction of energetic materials  

SciTech Connect

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.

Pruneda, C. O., LLNL

1996-09-01

406

A Study of Detonation Diffraction in the Ignition-and-Growth Model  

SciTech Connect

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.

Kapila, A K; Schwendeman, D W; Bdzil, J B; Henshaw, W D

2006-04-14

407

The morphological, structural and physical properties of ultra-thick C-axis oriented barium ferrite films  

NASA Astrophysics Data System (ADS)

Nowadays most of the existing circulators and phase shifters are the building blocks of high-performance phased-array radars and communications systems. Ferrite reciprocal and nonreciprocal components currently used in transmit/receive (T/R) modules, however are costly and bulky. The focus of this work was a detailed in-depth investigation of the phenomena surrounding the growth, characterization and modeling of ultra-thick film C-axis oriented Barium Hexaferrite films, which will integrate excellent magnetic properties, miniature size and low losses. Polycrystalline structures have been engineered using the Pulsed Laser Deposition (PLD) and Modified Liquid Phase Epitaxy (MLPE) reflow techniques. Unfortunately the Plasma Enhanced Chemical Vapor Deposition (PECVD) showed only mediocre physical quality and magnetic properties of the films do not support a further pursue of these techniques. This research introduces the novel Modified Injection Molding (MIM) technique for fabrication of ultra-thick M-type Barium Ferrite films that can be possibly utilized as monolithic microwave integrated circuits (MMIC) devices with operating range from 1 to 100GHZ. This is an extremely low cost production, with very high rate of repetition and success. The fabricated magnetic pucks show an average coercivity of 4500 Oe, a squareness SQ= Mr/Ms = 0.93 and a magnetization saturation 4piM S above 4500 Gauss. Polycrystalline self-biased BaM films with thickness of up to 2mm have been compared to films produced by PECVD, PLD and MLPE grown samples on different substrates. Due to the low growth rate, the PECVD and PLD techniques should not be considered for industrial application. The MLPE technique has shown some very promising signs: polycrystalline films, and excellent c-axis orientation of the magnetic moment. The coercivity of the MLPE grown thick films > 400 micron was found to be about 700 Oe. The films obtained using MIM give unlimited physical dimensions of the fabricated films. For actual simulation and possible application as a monolithic microwave integrated circuit device, a BaFe12O19 puck was fabricated with thickness of 500 mum and a radius of 450 mum. The research conducted shows this new technique will prove to be cost effective and with much higher efficiency than the other conventional techniques for thin film fabrication.

Kranov, Yanko Alexandrov

408

Investigating the orientational order in smectic liquid crystals  

NASA Astrophysics Data System (ADS)

This thesis is composed of two projects. The first one is the investigation of a reversed phase sequence, which subsequently leads to the discovery of a novel Smectic-C liquid crystal phase. The 10OHFBBB1M7 (10OHF) compound shows a reversed phase sequence with the SmC*d4 phase occurring at a higher temperature than the SmC* phase. This phase sequence is stabilized by moderate doping of 9OTBBB1M7 (C9) or 11OTBBB1M7 (C11). To further study this unique phase sequence, the mixtures of 10OHFBBB1M7 and its homologs have been characterized by optical techniques. In order to perform the resonant X-ray diffraction experiment, we have added C9 and C11 compounds to the binary mixtures and pure 10OHF. In two of the studied mixtures, a new smectic-C* liquid crystal phase with six-layer periodicity has been discovered. Upon cooling, the new phase appears between the SmC*a phase having a helical structure and the SmC*d4 phase with four-layer periodicity. The SmC*d6 phase shows a distorted clock structure. Three theoretical models have predicted the existence of a six-layer phase. However, our experimental findings are not consistent with the theories. The second project involves the mixtures of liquid crystals with different shapes. The role of different interactions in stabilizing the antiferroelectric smectic liquid crystal phases have been a long-standing questions in the community. By mixing the antiferroelectric smectic liquid crystal with achiral liquid crystal molecules with rod and hockey-stick shapes, distinct different behaviors are obtained. In the case of the mixtures of chiral smectic liquid crystals with rod-like molecules, all the smectic-C* variant phases vanish with a small amount of doping. However, the hockey-stick molecule is much less destructive compared to the rod-like molecule. This suggests that the antiferroelectric smectic liquid crystal molecules may have a shape closer to a hockey-stick rather than a rod.

Wang, Shun

409

Type of physical activity, muscle strength, and pubertal stage as determinants of bone mineral density and bone area in adolescent boys.  

PubMed

The present study was conducted to evaluate the influence of different types of weight-bearing physical activity, muscle strength, and puberty on bone mineral density (BMD, g/cm2) and bone area in adolescent boys. Three different groups were investigated. The first group consisted of 12 adolescent badminton players (age 17.0 +/- 0.8 years) training for 5.2 +/- 1.9 h/week. The second group consisted of 28 ice hockey players (age 16.9 +/- 0.3 years) training for 8.5 +/- 2.2 h/week. The third group consisted of 24 controls (age 16.8 +/- 0.3 years) training for 1.4 +/- 1.4h/week. The groups were matched for age, height, and pubertal stage. BMD, bone mineral content (BMC, g), and the bone area of the total body, lumbar spine, hip, femur and tibia diaphyses, distal femur, proximal tibia, and humerus were measured using dual-energy X-absorptiometry. When adjusting for the difference in body weight between the groups, the badminton players were found to have significantly higher BMD (p < 0.05) of the trochanter and distal femur compared with the ice hockey players despite a significantly lower weekly average training. The badminton players had higher BMD compared with the control with the control group at all weight-bearing BMD sites, except at the diaphyses of the femur and tibia and lumbar spine. The independent predictors of bone density were estimated by adjusting BMC for the bone area in a multivariate analysis among all subjects (n = 64). Accordingly, the bone density of all sites except the spine was significantly related to muscle strength and height, and the bone density of the total body, neck, trochanter, distal femur, and proximal tibia was significantly related to type of physical activity (beta = 0.09-0.33, p < 0.05). The bone area values at different sites were strongly related to muscle strength and height and less strongly related to the type of physical activity and pubertal stage. In conclusion, it seems that during late puberty in adolescent boys the type of weight-bearing physical activity is an important determinant of bone density, while the bone area is largely determined by parameters related to body size. The higher BMD at weight-bearing sites in badminton players compared with ice hockey players, despite significantly less average weekly training, indicates that physical activity including jumps in unusual directions has a great osteogenic potential. PMID:9661078

Nordström, P; Pettersson, U; Lorentzon, R

1998-07-01

410

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

PubMed Central

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.

Sajko, Sandy; Stuber, Kent

2009-01-01

411

Television violence and children's aggression: testing the priming, social script, and disinhibition predictions.  

PubMed

The effect of television violence on boys' aggression was investigated with consideration of teacher-rated characteristic aggressiveness, timing of frustration, and violence-related cues as moderators. Boys in Grades 2 and 3 (N = 396) watched violent or nonviolent TV in groups of 6, and half the groups were later exposed to a cue associated with the violent TV program. They were frustrated either before or after TV viewing. Aggression was measured by naturalistic observation during a game of floor hockey. Groups containing more characteristically high-aggressive boys showed higher aggression following violent TV plus the cue than following violent TV alone, which in turn produced more aggression than did the nonviolent TV condition. There was evidence that both the violent content and the cue may have suppressed aggression among groups composed primarily of boys low in characteristic aggressiveness. Results were interpreted in terms of current information-processing theories of media effects on aggression. PMID:3681656

Josephson, W L

1987-11-01

412

Robotic nephropexy in case of symptomatic nephroptosis.  

PubMed

We found only a recent report of robotic-assisted nephropexy, in a young female with associated dismembered pyeloplasty. Herein we present the first case of isolated robotic nephropexy. A 34-year old female was referred to our Urological Division history of right flank pain and evidence at intravenous urography of a 5-6 cm descent of right kidney moving from supine to erect position. The robotic nephropexy was performed with a transperitoneal approach and 4 trocars. The kidney was wrapped up with a Parietex Composite (PCO) mesh (Tyco Healthcare), previously precut in an hockey stick shape to obtain a "spoon effect" to push up the lower pole of kidney. Despite the laparoscopic or retroperitoneoscopic procedures, the robotic-assisted nephropexy appears easier, with the particular advantages of the intracorporeal suturing and a better intraoperative view. The use of mesh, in our opinion, is preferable respect the decapsulation of the kidney, to avoid unnecessary blood loss and possible scarring. PMID:22184841

Baldassarre, Emanuele; Marcangeli, Paolo; Vigano, Massimo; Vittoria, Ivano; Pone, Domenico; Gillo, Arianna; Pierini, Paolo

2011-09-01

413

NBC Learn: Science of the Olympic Winter Games  

NSDL National Science Digital Library

This is the portal for a collection of 16 short videos that explore the science behind winter olympic sports. The videos aim to provide engaging real-world examples of key concepts, including Newton's Laws of Motion, momentum, projectile motion, action/reaction, and friction. Athletes are featured in each video, along with physicists, materials scientists, engineers, biologists, and chemists. Several videos document how scientists and engineers work together to design the high-tech skis, skates, and bobsleds used by contestants in the Olympics. This resource, funded by the National Science Foundation, is part of a larger set of resources published by NBC which include the science of NHL Hockey and the science of NFL Football.

2014-02-03

414

Air levels and mutagenicity of PM-10 in an indoor ice arena  

SciTech Connect

The authors report here their results from a preliminary study to evaluate a methodology for surveying air quality by measuring concentrations of PM-10 and the corresponding concentrations of mutagenic activity. The PM-10 was collected, during several hockey games at an ice arena using an Indoor Air Sampling Impactor (IASI) developed by Marple et al. During the course of the study, smoking restrictions were imposed in the stadium and the impact of these restrictions on PM-10 levels was also evaluated. The mutagenic activities of solvent extracts of the PM-10 were determined using the microsuspension modification of the Samonella typhimurium/microsome test. Mutagenic activity has often been used as a rough index of exposure to potential carcinogens and mutagens and to help define their sources.

Georghiou, P.E.; Blagden, P.A. (Memorial Univ. of Newfoundland, St. Johns (Canada)); Snow, D.A.; Winsor, L. (Geortec Ltd., St. Johns, Newfoundland (Canada)); Williams, D.T. (Health and Welfare Canada, Ottawa, Ontario (Canada))

1989-12-01

415

Coefficient of restitution of sports balls: A normal drop test  

NASA Astrophysics Data System (ADS)

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.

Haron, Adli; Ismail, K. A.

2012-09-01

416

[What are the recommendations for sport activity following total hip or total knee arthroplasty?].  

PubMed

Total hip and knee arthroplasty are surgical procedures usually performed in older adults aged 65-70 years and more, who suffer from arthritic joint degeneration, in order to relieve pain and improve functioning. In the past decade there have been more and more documentations of younger people, 50-60 years old and even less, who expect to participate in physical activity following these procedures. The trend today is to recommend activities which exert mild pressure on the implants such as swimming, cycling, golf, bowling, walking and cycling. It is not recommended to participate in sports activities that place greater pressure on the implants such as soccer, football, volleyball, handball, basketball, hockey and jogging. Such high-stress activities may cause early loosening of implants, as described in the article by Keren et al. in this issue: "Sport activity after hip and knee arthroplasty". PMID:24416821

Tsur, Azmon; Volpin, Gershon

2013-11-01

417

Dental injuries at the 1989 Canada games: an epidemiological study.  

PubMed

The management and prevention of dental trauma is an integral part of the medical services provided at major athletic events. This paper reviews the organization and delivery of the dental services provided at the 1989 Canada Games. The nature, incidence and management of the dental problems reported in the participant population of 3,411 athletes are also described. During the two-week competition, 15 participants were assessed and treated for various dental conditions, including hard- and soft-tissue injury of the oral cavity, and temporomandibular joint sprain. The sports with the highest incidence of dental injury for the male population were wrestling (one per cent) and basketball (0.8 per cent). For the female population, these sports were basketball (2.5 per cent) and field hockey (1.3 per cent). The dental services provided during the games included emergency assessment and treatment, fabrication of mouthguards, and in-service education to medical team members. PMID:1356606

Lee-Knight, C T; Harrison, E L; Price, C J

1992-10-01

418

Participation in Aesthetic Sports and Girls' Weight Concerns at Ages 5 and 7 Years  

PubMed Central

Objective The relationship between participation in aesthetic, or appearance-oriented, sports and weight concerns was assessed among young girls. Method Participants were part of a larger longitudinal study and included 197 and 192 girls and their mothers when girls were 5 and 7 years, respectively. At each age, girls’ weight concerns and sport participation were assessed and girls were classified as participating in aesthetic sports (dance, gymnastics, cheerleading, baton twirling, swimming, aerobics, figure skating), non-aesthetic sports (volleyball, soccer, basketball, softball, hockey, tennis, martial arts, track) or no sports. Results Girls in the aesthetic sport group reported higher weight concerns than girls in the nonaesthetic and no sport groups at ages 5 and 7 years. In addition, girls participating in aesthetic sports at ages 5 and 7 years reported the highest weight concerns at age 7. Discussion Participation in aesthetic, or appearance-oriented, sports may foster a heightened focus on weight and body shape among girls.

Davison, Kirsten Krahnstoever; Earnest, Mandy B.; Birch, Leann L.

2008-01-01

419

Scores on field independence and performance in snooker.  

PubMed

The purpose of this study was to compare the scores on the Group Embedded Figures Test, a measure of field dependence, for 25 male intermediate-level snooker players with scores of 25 intermediate-level sportsmen engaged in soccer, rugby, field hockey, and tennis and to examine the relation between scores on field dependence and performance on a snooker decision-making test. All the snooker players also took a test of decision making in snooker. The snooker players scored significantly more field independent than the sports-science majors on the Group Embedded Figures Test. A Pearson correlation of 0.78 was obtained between scores on the Group Embedded Figures Test and the decision-making test. As there may be an association between scores on field dependence and decision making in snooker, further research should examine sports like lawn bowls and pool where decisions are made in a static environment. PMID:8170763

McMorris, T; Francis, M; MacDonald, A; Priday, K

1993-12-01

420

Percutaneous transcatheter arterial embolization in haemodynamically stable patients with blunt splenic injury  

PubMed Central

Background The nonoperative management of the blunt splenic injury in haemodynamically stable patients has become an accepted treatment in recent years. We present a case of the blunt splenic injury successfully treated by supraselective embolization with microspheres. Case report. A young hockey player was brought to the Emergency Department with the history of blunt abdominal trauma 2 h earlier. A Grade III splenic injury with haemoperitoneum was diagnosed on sonographic evaluation and the patient was treated with the selective distal splenic artery embolization with microspheres. Postprocedural ultrasound and computed tomography follow-up a year later revealed only a small area of parenchymal irregularity. Conclusions The percutaneous splenic arterial embolization has a major role in the management of traumatic splenic injuries. Embolization is particularly beneficial in injuries of grade III or higher.

Popovic, Peter; Stanisavljevic, Dragoje; Jeromel, Miran

2010-01-01

421

Possible disease transmission by contaminated mouthguards in two young football players.  

PubMed

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

Glass, R Thomas; Wood, C Rieger; Bullard, James W; Conrad, Robert S

2007-01-01

422

The relative age effect in elite sport: the French case.  

PubMed

The relative age effect (RAE) is considered a common phenomenon in elite sport. Howeven it has not been examined systematically in previous research, and the mechanisms likely to generate or to limit such an effect are little understood. This paper investigates the prevalence of the RAE in French professional championship-level players, taking into account the potential influence of gender. Among all investigated sports, no statistically significant RAE was found, except for male ice hockey. For male handball and rugby union a trend was detected, but the RAE did not appear statistically significant. In line with previous'studies, n osignificant RAEs were found in female elite sports. The results are discussed with regard to the potential mechanisms underlying RAE. PMID:19650399

Delorme, Nicolas; Boiché, Julie; Raspaud, Michel

2009-06-01

423

Social status moderates the relationship between facial structure and aggression.  

PubMed

A growing body of evidence has linked individual differences in facial structure-in particular, the facial width-to-height ratio (FWHR)-to social behaviors, including aggression, cheating, and nonreciprocation of trust. In the research reported here, we extended this work by demonstrating that the association between FWHR and aggression is moderated by subjective and objective measures of social status. In Study 1 (N = 237 college students), FWHR was positively correlated with aggressive behavior, but only among men reporting relatively low social status. In Study 2 (N = 891 professional hockey players), FWHR was positively correlated with penalty minutes, but only among players who earned relatively low salaries. Collectively, these studies provide compelling evidence for the role of social status in moderating the relationship between facial structure and aggression, indicating that FWHR is a robust predictor of aggressive behavior, but only in the context of relatively low social status. PMID:24068116

Goetz, Stefan M M; Shattuck, Kraig S; Miller, Robert M; Campbell, Jocelyn A; Lozoya, Elianna; Weisfeld, Glenn E; Carré, Justin M

2013-11-01

424

High-intensity cardiac rehabilitation training of a police officer for his return to work and sports after coronary artery bypass grafting.  

PubMed

A 39-year-old male police officer with coronary artery disease enrolled in our cardiac rehabilitation (CR) program after coronary artery bypass grafting. He wanted to return not only to his job but also to playing ice hockey and outdoor soccer, and his responses to a self-assessment scale confirmed that he identified strongly as an athlete. On the basis of this unique profile, the CR staff designed an occupation- and sport-specific exercise program that was symptom limited and enabled the patient to train safely, but earlier and at a higher intensity than is typically allowed in conventional CR programs. The exercises were selected to replicate the various combinations of muscular strength, agility, and cardiovascular endurance required by the patient's police work and two competitive team sports. He completed the high-intensity training with no clinically significant adverse symptoms. PMID:23382610

Adams, Jenny; Berbarie, Rafic F

2013-01-01

425

Randomized Grain Boundary Liquid Crystal Phase  

NASA Astrophysics Data System (ADS)

The formation of macroscopic, chiral domains, in the B4 and dark conglomerate phases, for example, is a feature of bent-core liquid crystals resulting from the interplay of chirality, molecular bend and molecular tilt. We report a new, chiral phase observed in a hockey stick-like liquid crystal molecule. This phase appears below a smectic A phase and cools to a crystal phase. TEM images of the free surface of the chiral phase show hundreds of randomly oriented smectic blocks several hundred nanometers in size, similar to those seen in the twist grain boundary (TGB) phase. However, in contrast to the TGB phase, these blocks are randomly oriented. The characteristic defects in this phase are revealed by freeze-fracture TEM images. We will show how these defects mediate the randomized orientation and discuss the intrinsic mechanism driving the formation of this phase. This work is supported by NSF MRSEC Grant DMR0820579 and NSF Grant DMR0606528.

Chen, D.; Wang, H.; Li, M.; Glaser, M.; Maclennan, J.; Clark, N.

2012-02-01

426

Bronchoconstriction provoked by exercise in a high-particulate-matter environment is attenuated by montelukast.  

PubMed

Airborne ultrafine and fine particulate matter (PM1 from fossil-fueled internal combustion engines may cause abnormal airway narrowing. Because of high PM1 exposure from ice resurfacing machines, the ice-rink athlete is especially vulnerable to PM1 toxicity. The purpose of this study was to evaluate protection by a single dose of montelukast in college ice hockey players following PM1 exposure exercise. Nine male ice hockey players (age 19.3+/-1.22 yr) performed 4 randomized, double-blinded, high-intensity, 6-min cycle ergometer trials in low [PM1] (2260+/-500 particles/cm3) and high [PM1] (348,600+/-121,600 particles/cm3) after placebo or montelukast. Pre- and postspirometry showed similar peak FEV1 (forced expiratory volume in 1 s) falls between placebo and montelukast after low [PM1] trials (14.5+/-18.06 vs. 9.5+/-11.75% of baseline, respectively). Peak FEV1 falls after high [PM1] trials were greater for placebo than for montelukast (17.3+/-9.79% vs. 1.7+/-5.77% of baseline; p<.0001). High [PM1] FEV1 fall after exercise following montelukast ingestion was less than after exercise following placebo ingestion under high and low [PM1] conditions and after exercise following montelukast ingestion under low [PM1] conditions at 5, 10, and 15 min postchallenge (p<.004, .0006, .009, respectively). Montelukast provided greater protection against bronchoconstriction after exercise during high [PM1] than low [PM1] exposure (approximately 90% vs. approximately 35%), suggesting that bronchoconstriction from PM1 exposure is predominately leukotriene mediated. The precise mechanism of airborne PM1-induced leukotriene-mediated airway narrowing remains unclear. PMID:15764487

Rundell, Kenneth W; Spiering, Barry A; Baumann, Jennifer M; Evans, Tina M

2005-02-01

427

Can pre-season fitness measures predict time to injury in varsity athletes?: a retrospective case control study  

PubMed Central

Background The ability to determine athletic performance in varsity athletes using preseason measures has been established. The ability of pre-season performance measures and athlete’s exposure to predict the incidence of injuries is unclear. Thus our purpose was to determine the ability of pre-season measures of athletic performance to predict time to injury in varsity athletes. Methods Male and female varsity athletes competing in basketball, volleyball and ice hockey participated in this study. The main outcome measures were injury prevalence, time to injury (based on calculated exposure) and pre-season fitness measures as predictors of time to injury. Fitness measures were Apley’s range of motion, push-up, curl-ups, vertical jump, modified Illinois agility, and sit-and-reach. Cox regression models were used to identify which baseline fitness measures were predictors of time to injury. Results Seventy-six percent of the athletes reported 1 or more injuries. Mean times to initial injury were significantly different for females and males (40.6% and 66.1% of the total season (p?hockey or basketball. Conclusions When accounting for exposure, gender, sport and fitness measures, prediction of time to injury was influenced most heavily by gender and sport.

2012-01-01

428

Unrecognized pediatric partial achilles tendon injury followed by traumatic completion: a case report and literature review.  

PubMed

Achilles tendon ruptures are a relatively common athletic injury but are exceedingly rare in the pediatric population. We describe the case of a 10-year-old ice hockey player who experienced an Achilles tendon injury from a laceration to the posterior leg from a skate blade that led to a partial tendon laceration. This tendon injury was initially unrecognized despite an emergency department evaluation. The patient continued to complain of weakness and paresthesia after the skin laceration had healed. A traumatic dorsiflexion injury while running several weeks later led to a traumatic complete tendon rupture. The clinical, operative, and physical therapy records were reviewed to complete the history, treatment, and rehabilitation progress. The initial laceration injury had occurred 6 weeks before presentation, and the traumatic dorsiflexion injury had occurred 2 days before referral to an acute orthopedics clinic. Open repair was performed several days after the traumatic completion of the laceration, and the patient was immobilized in a cast for 5 weeks. The patient had weaned off crutches by 10 weeks postoperatively and had returned to some activities and light skating at 5.5 months. A full return to running and ice hockey had been achieved by 8 months postoperatively. The optimal repair for this injury has not been well established in published studies. We have concluded that laceration injuries have the potential to mask tendon injuries and that prolonged symptoms after a laceration should suggest occult pathologic features. Open tendon repair is a viable treatment option in the pediatric patient with Achilles tendon ruptures. A return to activities within a reasonable period can be expected with robust physical therapy. PMID:24713492

Vasileff, William Kelton; Moutzouros, Vasilios

2014-01-01

429

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

SciTech Connect

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.

Michelotti, L.; Kick, R.

1990-08-27

430

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

SciTech Connect

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.

Omatete, O.O. [Oak Ridge National Lab., TN (United States); Van Dillen, G.L., Jr. [Ceramic Magnetics, Inc., Fairfield, NJ (United States)

1996-03-01

431

The submarine groundwater discharge as a carbon source to the Baltic Sea  

NASA Astrophysics Data System (ADS)

Submarine Groundwater Discharge (SGD) is an important, yet poorly recognized pathway of material transport to the marine environment. This work reports on the results of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations in the groundwater seeping to the Bay of Puck. The loads of carbon via SGD were quantified for the Baltic Sea sub-basins and the entire Baltic Sea. The annual averages of DIC and DOC concentrations in the groundwater were equal to 64.5 ± 10.0 mg C L-1 and 5.8 ± 0.9 mg C L-1. The DIC and DOC fluxes via SGD to the Baltic Sea were estimated at 283.6 ± 66.7 kt yr-1 and 25.5 ± 4.2 kt yr-1. The SGD derived carbon load to the Baltic Sea is an important component of carbon budget, which turns the status of the sea into firmly heterotrophic. The carbon load to the World Ocean, which was calculated basing on few reports on groundwater discharges and the measured carbon concentrations, amounts to- (142-155) × 103 kt yr-1 (DIC), and (13-14) × 103 kt yr-1 (DOC). The carbon flux via SGD amounts to some 25% of the riverine carbon load, and should be included into the World Ocean carbon budget.

Szymczycha, B.; Maciejewska, A.; Szczepanska, A.; Pempkowiak, J.

2013-02-01

432

Measurement of areal density in the ablators of inertial-confinement-fusion capsules via detection of ablator (n, n'?) gamma-ray emission  

NASA Astrophysics Data System (ADS)

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 12C nuclei in the compressed plastic ablators. The emission of 12C(n,n'?) 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 12C(n,n'?) 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 12C 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/cm2, are comparable to values calculated in 1D radiation-hydrodynamic simulations, and measured by charged-particle techniques.

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

2013-04-01

433

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

NASA Astrophysics Data System (ADS)

Free radicals in gamma- or x-irradiated ultra-high molecular weight polyethylene (UHMWPE) are investigated as a function of vitamin E (alpha-tocopherol (?-T)). ?-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 ?-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 ?-T radical (tocopheroxyl).

Walters, Benjamin; Jahan, Muhammad

2008-03-01

434

Isolation and preliminary characterization of u. v. -sensitive mutants from the human cell line EUE  

SciTech Connect

Five u.v. light-sensitive clones were isolated in the EUE cell line by means of a modified form of the original 5-bromodeoxyuridine (BUdR)-light method worked out by Puck and Kao for the isolation of nutritional mutants. A cell population was mutagenized with ethylmethanesulfonate. After the expression time, cells were u.v.-irradiated and incubated with BUdR to label excision patches in repair proficient cells. A subsequent irradiation with black light caused DNA strand breakage in BUdR-substituted cells. During BUdR treatment, hydroxyurea and a fluorochrome (Hoechst 33258) were added to possibly enhance the analogue incorporation into DNA and to increase the photolability of BUdR containing sequences, respectively. Out of 192 colonies selected with this method, 38 were isolated and tested for their u.v.-sensitivity. Five of them showed significant, reproducible differences with respect to the parental line. As a partial characterization, the five u.v.-sensitive clones were assayed for unscheduled (/sup 3/H)thymidine incorporation after exposure to u.v. light, by means of liquid scintillation spectrometry and autoradiography. In all clones. DNA repair synthesis was significantly decreased with respect to the parental line.

Fiorio, R.; Frosina, G.; Abbondandolo, A.

1983-01-01

435

Mimas: Tectonic structure and geologic history  

NASA Technical Reports Server (NTRS)

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.

Croft, Steven K.

1991-01-01

436

Hubble Space Telescope Astrometric Observations and Orbital Mean Motion Corrections for the Inner Uranian Satellites  

NASA Astrophysics Data System (ADS)

The 10 small inner satellites of Uranus were discovered in 1986 with Voyager 2 and not seen again until 1994, when eight were recovered with the Hubble Space Telescope Wide Field Planetary Camera 2 for astrometric, dynamical, and photometric studies. Thirty-three exposures were taken on 1994 August 14 with the PC1 chip in the BVRI filters. Measurable images of Ariel and Miranda were also obtained on the same CCD frames with those of the faint satellites. We present here the astrometric observations of these eight satellites relative to Miranda, as well as corrected orbital mean motions for them. For the full-well images of Ariel and Miranda, the astrometric limitation was due to an inadequate geometric distortion correction and distance from center. For the faint inner satellites, the astrometric precision varied from 50 mas for Bianca (V = 23 mag) to 9 mas for Puck (V = 20 mag) and was due primarily to a centroiding error caused by a low signal-to-noise ratio. The orbits of Owen & Synnott for the inner satellites were compared with these observations and corrections derived to their mean daily motions. While the orbits of Owen & Synnott proved to be better than their errors indicated, the new mean motions are 2 orders of magnitude more precise.

Pascu, Dan; Rohde, James R.; Seidelmann, P. Kenneth; Wells, Eddie N.; Kowal, Charles T.; Zellner, Ben H.; Storrs, Alex D.; Currie, Douglas G.; Dowling, Daniel M.

1998-03-01

437

Thermo-mechanical self-adaptive ball screw drive using thermal shape memory effect  

NASA Astrophysics Data System (ADS)

An adaptive precision ball screw drive concept is presented in which a self-sufficient actuator is able to adjust the axial preload during the operation. The adjustment is effected by thermal shape memory alloy pucks, which either expand or contract according to the surrounding temperature field of the process. For this purpose, no external energy is needed and so the system is self-supported (energy harvesting). In this case, the extrinsic two-way shape memory effect occurs and the reversible full cycle of shape change is accomplished by a bias force of a flexure. Basing on temperature and force measurements on a double nut ball screw, a thermo-mechanical model is developed. Using the investigated principles adaptive mechanisms, a shape memory-based actuator is designed. Initial tests reveal an unwanted reduction of the preload of up to 800 N with rising temperature. Due to the shape memory actuation device, experiments results show an increase in axial load in approximated 70 % of the reduction.

Navarro y de Sosa, I.; Bucht, A.; Junker, T.; Pagel, K.; Drossel, W.-G.

2013-04-01

438

Failure Criteria for FRP Laminates in Plane Stress  

NASA Technical Reports Server (NTRS)

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.

Davila, Carlos G.; Camanho, Pedro P.

2003-01-01

439

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

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.

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. [Los Alamos National Laboratory, P. O. Box 1663, Los Alamos, New Mexico 87545 (United States); Horsfield, C. J.; Rubery, M. S. [Atomic Weapons Establishment, Aldermaston, Berkshire RG7 4PR (United Kingdom); Miller, E. K. [National Security Technologies, LLC, Santa Barbara, California 93111 (United States); Grafil, E. [Colorado School of Mines, Golden, Colorado 80401 (United States); Stoeffl, W.; Church, J. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Glebov, V. Yu.; Duffy, T. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

2013-04-15

440

Planetary nomenclature  

NASA Technical Reports Server (NTRS)

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.

Strobell, M. E.; Masursky, Harold

1987-01-01

441

Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.  

PubMed

Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-)adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability), and secondly they must competently perform user-specified tasks (usefulness). The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee) framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks. PMID:24901702

Haasdijk, Evert; Bredeche, Nicolas; Eiben, A E

2014-01-01

442

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

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

443

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

SciTech Connect

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.

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

444

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

445

Combining Environment-Driven Adaptation and Task-Driven Optimisation in Evolutionary Robotics  

PubMed Central

Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-)adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability), and secondly they must competently perform user-specified tasks (usefulness). The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms–survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee) framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a ‘market mechanism’ that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

Haasdijk, Evert; Bredeche, Nicolas; Eiben, A. E.

2014-01-01

446

A direct method for obtaining the critical state in two and three dimensions  

NASA Astrophysics Data System (ADS)

A method for obtaining the critical state in three dimensions is described. This uses an extension of a previous 1D model based on flux line motion in which the equations are not based on an E-J curve, which leads to time dependence. In order to make clear the connection between the scalar potential, the particular vector potential derived and the electrostatic surface charges, it has proved necessary to start from eddy currents in a normal conductor. The eddy current solutions for a normal conductor are the same as those for a London superconductor in a DC field, except that although a scalar potential is needed there are no electrostatic charges. The problem of a superconducting puck in a field parallel to the faces is solved. It is assumed that the electric field is parallel to the current density which is quite probable for high Tc superconductors, but other criteria could be used. Like other 3D solutions the computation takes a long time; even this relatively simple case takes 7 h with a 1.3 GHz PC. However this was using a standard PC with default parameters in the finite element package so there is room for optimization. All the results were obtained with FlexPDE.

Campbell, A. M.

2009-03-01

447

Links between detonation wave propagation and reactive flow models.  

SciTech Connect

An accurate reactive flow model is necessary to be able to predict the initiation properties of explosives by complicated shock structures, but a very fine the spatial resolution is needed in reactive flow to reproduce the detailed dynamics of a detonation wave. However, it is not often necessary to use a reactive flow model to simulate the motion of a fully-developed detonation wave. In many situations the same results can be obtained with a coarse computational mesh using programmed burn techniques. In the WBL model [Lambourn89,Swift93], an eikonal detonation wave propagates through a body of explosive at a speed which depends on the curvature of the wave. The model describes the motion of the leading shock of the detonation wave. Here we use the level set method for integrating the WBL equations in time [Collyer98,Bdzil93,Osher88,Aslam98]. This method is attractive because complicated detonation wave shapes can be represented simply. It was found possible to initialize the level set field by a set of source points derived from a reactive flow simulation, by taking 'trigger states' from the reactive flow. The level set scheme was generalized further to take account of motion of the material behind the detonation wave, allowing it to be used for simulations coupled with reactive flow, where detonation may propagate through preshocked and moving material. The modified level set scheme was implemented in 1D and 2D Lagrangian hydrocodes. Trial calculations were performed of initiation and detonation in the TATB-based explosive LX-17, using the Lee - Tarver model. A CJ detonation was simulated in order to verify that the modified level set algorithm operated correctly. The detonation speed was in very good agreement with the expected value. Single-shock initiation was simulated. The position - time history of the leading shock from the coupled model was in excellent agreement with full reactive flow; the pressure profiles were similar but not identical, because of the difference in material properties behind the WBL wave and the omission of the von Neumann spike from the WBL profiles. As a more interesting test, we simulated the shock-to-detonation transition on reflection of a weak shock from a rigid boundary. The position - time history of the leading shock was in good agreement. The pressure profiles varied much more than in the single-shock case, because the WBL calculation used the same propagation parameters and for simplicity imposed the same state at the end of the detonation zone as was used in the single-shock simulation. We have previously used quasisteady flow analysis to derive a reaction rate from experimental measurements of the relation between detonation speed and wave curvature, or vice versa [Swift93]. Reactive flow models have been developed for HMX-based explosives based on mesoscale representations of the components of the explosive [Mulford01], and using a temperature-dependent reaction rate which should be valid over a wide range of loading conditions. The quasisteady analysis scheme was extended to allow arbitrary reaction models to be investigated.

Swift, D. C. (Damian C.); White, S. J. (Stephen J.)

2002-01-01

448

Excess risk thresholds in ultrasound safety studies: statistical methods for data on occurrence and size of lesions.  

PubMed

Concerns about the safe use of clinical ultrasound (US) at diagnostic pressure levels (below a mechanical index, or MI, = 1.9) have stimulated considerable research in US risk assessment. The objective of the present study was to develop probability-based risk thresholds for US safety studies, to present statistical methods for estimating the thresholds and their standard errors and to compare these methods with the analysis based on a piecewise linear ("hockey stick") model. The excess risk at exposure level x > 0 was defined as the relative increase in the probability of a lesion at that level compared with the background probability of a lesion at exposure x = 0. The risk threshold was then defined as the exposure level at which the excess risk exceeded a specified level (e.g. 5% or 50%). Thus, given pressure-dependent estimates of the excess risk, the thresholds were estimated by solving the risk equation to obtain the pressure at which the target level of excess risk occurs. Threshold estimates of this type have been developed extensively in the literature for incidence (presence or absence) data. Only recently, however, have excess risk threshold estimates been derived for data in which lesion size (depth, surface area) is measured if present and a zero is recorded if the lesion is absent. Tobit regression was used to estimate pressure-dependent percentiles of the size distribution, and the excess risks were estimated from the tobit probability of a positive-valued response. The tobit model provides a well-established approach to modeling data constrained to be nonnegative. Solving the risk equation for the tobit model leads to risk threshold estimates that incorporate the information on size of observed lesions. Results using these probability-based risk estimates were compared with results for a piecewise linear ("hockey stick") model, which has also been used in the US safety literature, although it does not explicitly address the nonnegativity constraint in the sampling model. The comparisons were carried out for data from two previously published studies, from different laboratories, on US-induced lung hemorrhage. The thresholds derived from logistic regression of lesion occurrence and tobit regression of lesion size were quite consistent with each other and within sampling error. The hockey stick thresholds, defined as the exposure level at which the piecewise linear model for the probability of the expected size of a lesion bends upward, corresponded to quite different excess risk values for incidence (lesion occurrence) compared with size (lesion surface area or depth), although these methods have been developed previously for both types of data. The use of probability-based excess risk thresholds is recommended to obtain consistent incidence vs. size thresholds and to ensure that the thresholds are well-defined and interpretable independent of the details of the statistical model. PMID:15582228

Simpson, Douglas G; Ho, Moon-Ho; Yang, Yan; Zhou, Jianhui; Zachary, James F; O'Brien, William D

2004-10-01

449

Radiochemistry: A versatile diagnostic for the NIF ignition campaign  

SciTech Connect

The purpose of this paper is to provide quick, clear, concise information about radiochemical diagnostics for the NIF program. Radiochemistry is perhaps the most versatile, flexible and dynamic of all nuclear diagnostics because it provides quantitative data on multiple capsule performance parameters such as mix, asymmetry of implosion, shell and fuel {rho}R, yield, neutron spectral information, high energy neutron information, fill tube jets, charged particle stopping, and the fission yield of the hohlraum by employing a variety of nuclear reactions on materials either present naturally in the capsule or specifically doped into the capsule. The choice and location of the doped material, together with the specific nuclear reaction used to produce a measurable product nuclide or ratio of nuclides, provides significant diagnostic information on the performance of the capsule during the experiment. The nature of the experiment, design of the capsule including fuel(s), and desired diagnostic information would dictate the radiochemical dopants used on any given shot--not all reactions would be possible nor monitored on any given experiment. Some of this diagnostic information is obtainable with other diagnostics, for example, the neutron yield is measured using Cu-activation pucks or nTOF. The unique niche of radiochemistry, for which few other measurements are currently planned, is the quantification of ablator/fuel mix. This diagnostic can supply complementary information on ablator {rho}R, asymmetry and unique information on mix--three of the four important concerns of the ignition campaign. This paper will not discuss the additional nuclear chemistry and physics possible by utilizing radiochemistry collection and similar nuclear reactions.

Stoyer, M A; Cerjan, C J; Moody, K J; Hoffman, R D; Bernstein, L A; Shaughnessy, D A

2008-06-17

450

Entry/Exit Port testing, test report  

SciTech Connect

The Waste Receiving and Processing Module I (WRAP-1) facility must have the ability to allow 55-gallon drums to enter and exit glovebox enclosures. An Entry/Exit Port (Appendix 1, Figure 1), designed by United Engineers and Constructors (UE&C), is one method chosen for drum transfer. The Entry/Exit Port is to be used for entry of 55-gallon drums into both process entry gloveboxes, exit of 55-gallon drum waste pucks from the low-level waste (LLW) glovebox, and loadout of waste from the restricted waste management glovebox. The Entry/Exit Port relies on capture velocity air flow and a neoprene seal to provide alpha confinement when the Port is in the open and closed positions, respectively. Since the glovebox is in a slight vacuum, air flow is directed into the glovebox through the space between the overpack drum and glovebox floor. The air flow is to direct any airborne contamination into the glovebox. A neoprene seal is used to seal the Port door to the glovebox floor, thus maintaining confinement in the closed position. Entry/Exit Port testing took place February 17, 1993, through April 14, 1993, in the 305 building of Westinghouse Hanford Company. Testing was performed in accordance with the Entry/Exit Port Testing Test Plan, document number WHC-SD-WO26-TP-005. A prototype Entry/Exit Port built at the Hanford Site was tested using fluorescent paint pigment and smoke candles as simulant contaminants. This test report is an interim test report. Further developmental testing is required to test modifications made to the Port as the original design of the Port did not provide complete confinement during all stages of operation.

Winkelman, R.H.

1993-05-01

451

Seasonality in vegetation biometrics and its effects on sediment characteristics and meiofauna in Baltic seagrass meadows  

NASA Astrophysics Data System (ADS)

Seagrass meadows can act as ecosystem engineers, i.e., organisms that modify the availability of resources to other organisms. However, their possible positive impacts depend on the characteristics of the vegetation, and these can vary strongly seasonally. This study assesses seasonal variability in macrophyte taxonomic composition and seagrass biometrics in the temperate Baltic Sea eelgrass meadows. We hypothesize that the anticipated strong seasonality in vegetation cover induces parallel seasonal changes in seagrass engineering effects as indicated by changes in sediment characteristics and meiozoobenthic abundance, composition and diversity. Macrophytes, sediments, and fauna were sampled at two locations in the Puck Bay from vegetated bottoms and bare sands five times in one year. Zostera marina vegetation occurred throughout the year and showed strong seasonality with the highest values of shoot density, leaf length, and biomass in July (202.3 ± 30.0 95% CI shoots m-2) and the lowest in March (55.4 ± 15.0 shoots m-2). POC was significantly higher in vegetated sands, and these effects were evident throughout the study period regardless of variability in macrophyte vegetation. The density and diversity of meiofauna did not differ between the seagrass beds and bare sands even in summer months when vegetation was best developed. The lack of an effect of the seagrass meadows on the meiofauna can be explained by the relatively low shoot density and biomass of the studied seagrass meadows and/or higher macrobenthic predation on the vegetated bottom compared to bare sands. However, both the canopies of macrophytes and the effects of the vegetation on benthic systems could increase substantially over the course of the gradual, natural restoration of the seagrass meadows.

Jankowska, Emilia; W?odarska-Kowalczuk, Maria; Kotwicki, Lech; Balazy, Piotr; Kuli?ski, Karol

2014-02-01

452

Uranian Rings, Arcs, and Moons: New Results from HST  

NASA Astrophysics Data System (ADS)

We have obtained a series of very deep exposures of the Uranian ring-moon system using the High Resolution Channel (HRC) of the Advanced Camera for Surveys on the Hubble Space Telescope. Exposures are very long (240 seconds) and use the broad clear filter to maximize the signal-to-noise ratio obtained. The planet is vastly over-exposed but the camera is oriented so that saturated pixels bloom parallel to Uranus's pole and so do not interfere with the rings and moons to each side. In August 2003 we obtained 24 images during three consecutive orbits of HST, spanning a period of ˜ 4 hours. In August 2004 we carried out two repeat visits, each consisting of 40 images (five orbits of HST, ˜ 7 hours duration) and separated by 6.8 days. Initial observations resulted in the recovery of two satellites, Ophelia and S/1986 U 10 (IAU Circular #8192), and the discovery of two more, S/2003 U 1 and S/2003 U 2 (IAU Circular #8209). S/2003 U 1 orbits near semimajor axis 97,730 km, between Puck and Miranda. S/2003 U 2 orbits near 74,800 km, just interior to Belinda. We will report on the combined analysis of all these observations, which will enable us to further refine the orbits of the inner Uranian moons. Images of the inner ring system have been processed by subtracting a median frame from each individual image; this eliminates the strong gradient of scattered light from the planet. Subtracted frames show a host of arc-like features orbiting within the ring system. Most of these are located in Ring ? and represent subtle variations in reflectivity or width. The dynamics of these features will also be discussed.

Showalter, M. R.; Lissauer, J. J.

2004-11-01

453

Outer Rings and Chaotic Orbits in the Uranian System  

NASA Astrophysics Data System (ADS)

Hubble observations of the Uranian system, spanning 2003 to the present, have revealed two small regular satellites and two faint, outer rings. The satellite Mab (U XXVI) is 12 km in radius and orbits 97,735 km from the center of Uranus, between the orbits of Puck and Miranda. It shows a significant, unexplained orbital libration; its mean longitude in 2004 fell 1° behind that in 2003 and 2005. Cupid (U XXVII) is 9 km in radius and orbits at 74,392 km, just 863 km interior to the orbit of Belinda. These moons are locked in 44:43 resonance. Most of the other inner moons Belinda through Portia show measurable orbital changes in the last 20 years, suggesting subtle, possibly chaotic interactions. Both newly-discovered rings have been recovered from high-phase Voyager images, and photometry indicates that they are composed primarily of dust. Peak normal optical depths are 10-5. Ring R/2003 U 1 peaks at the orbit of Mab and is almost certainly produced by dust ejected from Mab's surface. It has a triangular profile with a full width of 20,000 km. R/2003 U 2 orbits at 67,300 km, and is bounded by the orbits of nearby Portia and Rosalind. No known moons fall within this region; we hypothesize that a belt of embedded, sub-km bodies serve as the unseen source of this dust. Recent Keck observations reveal that the inner ring is red but the outer ring is blue. Blue indicates that particle sizes are primarily sub-µm in size; the dynamical implications of this result are not currently understood. Support for this publication was provided by NASA through proposals GO-9823, GO-10102, and GO-10274 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS5-26555.

Showalter, Mark R.; Lissauer, J. J.; de Pater, I.

2006-06-01

454

Outer Rings and Chaotic Orbits in the Uranian System  

NASA Astrophysics Data System (ADS)

Hubble observations of the Uranian system, spanning 2003 to the present, have revealed two small regular satellites and two faint, outer rings. The satellite Mab (U XXVI) is 12 km in radius and orbits 97,735 km from the center of Uranus, between the orbits of Puck and Miranda. It shows a significant, unexplained orbital libration; its mean longitude in 2004 fell 1° behind that in 2003 and 2005. Cupid (U XXVII) is 9 km in radius and orbits at 74,392 km, just 863 km interior to the orbit of Belinda. These moons are locked in 44:43 resonance. Most of the other inner moons Belinda through Portia show measurable orbital changes in the last 20 years, suggesting subtle, possibly chaotic interactions. Both newly-discovered rings have been recovered from high-phase Voyager images, and photometry indicates that they are composed primarily of dust. Peak normal optical depths are 10-5. Ring R/2003 U 1 peaks at the orbit of Mab and is almost certainly produced by dust ejected from Mab's surface. It has a triangular profile with a full width of 20,000 km. R/2003 U 2 orbits at 67,300 km, and is bounded by the orbits of nearby Portia and Rosalind. No known moons fall within this region; we hypothesize that a belt of embedded, sub-km bodies serve as the unseen source of this dust. Recent Keck observations reveal that the inner ring is red but the outer ring is blue. Blue indicates that particle sizes are primarily sub-µm in size; the dynamical implications of this result are not currently understood. Support for this publication was provided by NASA through proposals GO-9823, GO-10102, and GO-10274 from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS5-26555.

Showalter, Mark R.; Lissauer, J. J.; de Pater, I.

2006-09-01

455

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

456

Automated Data Quality Assurance using OGC Sensor Web Enablement Frameworks for Marine Observatories  

NASA Astrophysics Data System (ADS)

Over the past years, environmental sensors have continuously improved by becoming smaller, cheaper, and more intelligent. Therefore, many sensor networks are increasingly deployed to monitor our environment. But due to the large number of sensor manufacturers, accompanying protocols and data encoding, automated integration and data quality assurance of diverse sensors in an observing systems is not straightforward, requiring development of data management code and manual tedious configuration. However, over the past few years it has been demonstrated that Open-Geospatial Consortium (OGC) frameworks can enable web services with fully-described sensor systems, including data processing, sensor characteristics and quality control tests and results. So far, the SWE framework does not describe how to integrate sensors on-the-fly with minimal human intervention. The data management software which enables access to sensors, data processing and quality control tests has to be implemented and the results have to be manually mapped to the SWE models. In this contribution, we describe a Sensor Plug & Play infrastructure for the Sensor Web by combining (1) OGC PUCK protocol - a simple standard embedded instrument protocol to store and retrieve directly from the devices the declarative description of sensor characteristics and quality control tests, (2) an automatic mechanism for data processing and quality control tests underlying the Sensor Web - the Sensor Interface Descriptor (SID) concept, as well as (3) a model for the declarative description of sensor which serves as a generic data management mechanism - designed as a profile and extension of OGC SWE's SensorML standard. We implement and evaluate our approach by applying it to the OBSEA Observatory, and can be used to demonstrate the ability to assess data quality for temperature, salinity, air pressure and wind speed and direction observations off the coast of Garraf, in the north-eastern Spain.

Toma, Daniel; Bghiel, Ikram; del Rio, Joaquin; Hidalgo, Alberto; Carreras, Normandino; Manuel, Antoni

2014-05-01