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Sample records for kletychen otgovor sled

  1. Single-cavity SLED device

    SciTech Connect

    Lippmann, B.A.

    1984-09-01

    The conventional SLED device used at SLAC requires two cavities. However, the same effect can be obtained with a single cavity; the theory and operation of the device is the same, only the hardware is changed. The single-cavity device is described here.

  2. Head for The Hills with Sled Safety in Mind

    MedlinePlus

    ... 13, 2017 (HealthDay News) -- When temperatures drop and snow falls, children are ready to reach for their hats, scarves -- and sleds. Sledding and snow tubing are among the fun winter activities that ...

  3. Issues Associated with a Hypersonic Maglev Sled

    NASA Technical Reports Server (NTRS)

    Haney, Joseph W.; Lenzo, J.

    1996-01-01

    Magnetic levitation has been explored for application from motors to transportation. All of these applications have been at velocities where the physics of the air or operating fluids are fairly well known. Application of Maglev to hypersonic velocities (Mach greater than 5) presents many opportunities, but also issues that require understanding and resolution. Use of Maglev to upgrade the High Speed Test Track at Holloman Air Force Base in Alamogordo New Mexico is an actual hypersonic application that provides the opportunity to improve test capabilities. However, there are several design issues that require investigation. This paper presents an overview of the application of Maglev to the test track and the issues associated with developing a hypersonic Maglev sled. The focus of this paper is to address the issues with the Maglev sled design, rather than the issues with the development of superconducting magnets of the sled system.

  4. Kick-Sledding: An Outdoor Activity for Everyone.

    ERIC Educational Resources Information Center

    Wilson, Susan

    1994-01-01

    Kick-sledding is an outdoor activity that originated in Scandinavia. Kick-sleds may be used on snowy roads, cross-country ski trails, and frozen lakes by anyone, including seniors, children, and mothers with babies. To ride a kick-sled, you stand holding onto a bar across the back of a chair attached to runners and propel yourself by kicking. (LP)

  5. 50 CFR 36.36 - Sled dogs and household pets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Sled dogs and household pets. 36.36... Sled dogs and household pets. The general trespass provisions of 50 CFR 26.21 shall not apply to household pets and sled, work, or pack dogs under the direct control of their owners or handlers, but...

  6. 50 CFR 36.36 - Sled dogs and household pets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Sled dogs and household pets. 36.36... Sled dogs and household pets. The general trespass provisions of 50 CFR 26.21 shall not apply to household pets and sled, work, or pack dogs under the direct control of their owners or handlers, but...

  7. 50 CFR 36.36 - Sled dogs and household pets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Sled dogs and household pets. 36.36... Sled dogs and household pets. The general trespass provisions of 50 CFR 26.21 shall not apply to household pets and sled, work, or pack dogs under the direct control of their owners or handlers, but...

  8. 50 CFR 36.36 - Sled dogs and household pets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Sled dogs and household pets. 36.36... Sled dogs and household pets. The general trespass provisions of 50 CFR 26.21 shall not apply to household pets and sled, work, or pack dogs under the direct control of their owners or handlers, but...

  9. 50 CFR 36.36 - Sled dogs and household pets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Sled dogs and household pets. 36.36... Sled dogs and household pets. The general trespass provisions of 50 CFR 26.21 shall not apply to household pets and sled, work, or pack dogs under the direct control of their owners or handlers, but...

  10. Molecular sled sequences are common in mammalian proteins

    PubMed Central

    Xiong, Kan; Blainey, Paul C.

    2016-01-01

    Recent work revealed a new class of molecular machines called molecular sleds, which are small basic molecules that bind and slide along DNA with the ability to carry cargo along DNA. Here, we performed biochemical and single-molecule flow stretching assays to investigate the basis of sliding activity in molecular sleds. In particular, we identified the functional core of pVIc, the first molecular sled characterized; peptide functional groups that control sliding activity; and propose a model for the sliding activity of molecular sleds. We also observed widespread DNA binding and sliding activity among basic polypeptide sequences that implicate mammalian nuclear localization sequences and many cell penetrating peptides as molecular sleds. These basic protein motifs exhibit weak but physiologically relevant sequence-nonspecific DNA affinity. Our findings indicate that many mammalian proteins contain molecular sled sequences and suggest the possibility that substantial undiscovered sliding activity exists among nuclear mammalian proteins. PMID:26857546

  11. Gouge initiation in high-velocity rocket sled testing

    NASA Astrophysics Data System (ADS)

    Tachau, R. D. M.; Trucano, T. G.; Yew, C. H.

    1994-07-01

    A model is presented which describes the formation of surface damage 'gouging' on the rails that guide rocket sleds. An unbalanced sled can randomly cause a very shallow-angle, oblique impact between the sled shoe and the rail. This damage phenomenon has also been observed in high-velocity guns where the projectile is analogous to the moving sled shoe and the gun barrel is analogous to the stationary rail. At sufficiently high velocity, the oblique impact will produce a thin hot layer of soft material on the contact surfaces. Under the action of a normal moving load, the soft layer lends itself to an anti-symmetric deformation and the formation of a 'hump' in front of the moving load. A gouge is formed when this hump is overrun by the sled shoe. The phenomenon is simulated numerically using the CTH strong shock physics code, and the results are in good agreement with experimental observation.

  12. Gouge initiation in high-velocity rocket sled testing

    SciTech Connect

    Tachau, R.D.M.; Trucano, T.G.; Yew, C.H.

    1994-07-01

    A model is presented which describes the formation of surface damage ``gouging`` on the rails that guide rocket sleds. An unbalanced sled can randomly cause a very shallow-angle, oblique impact between the sled shoe and the rail. This damage phenomenon has also been observed in high-velocity guns where the projectile is analogous to the moving sled shoe and the gun barrel is analogous to the stationary rail. At sufficiently high velocity, the oblique impact will produce a thin hot layer of soft material on the contact surfaces. Under the action of a normal moving load, the soft layer lends itself to an anti-symmetric deformation and the formation of a ``hump`` in front of the moving load. A gouge is formed when this hump is overrun by the sled shoe. The phenomenon is simulated numerically using the CTH strong shock physics code, and the results are in good agreement with experimental observation.

  13. Reference PMHS Sled Tests to Assess Submarining.

    PubMed

    Uriot, Jérôme; Potier, Pascal; Baudrit, Pascal; Trosseille, Xavier; Petit, Philippe; Richard, Olivier; Compigne, Sabine; Masuda, Mitsutoshi; Douard, Richard

    2015-11-01

    Sled tests focused on pelvis behavior and submarining can be found in the literature. However, they were performed either with rigid seats or with commercial seats. The objective of this study was to get reference tests to assess the submarining ability of dummies in more realistic conditions than on rigid seat, but still in a repeatable and reproducible setup. For this purpose, a semi-rigid seat was developed, which mimics the behavior of real seats, although it is made of rigid plates and springs that are easy to reproduce and simulate with an FE model. In total, eight PMHS sled tests were performed on this semirigid seat to get data in two different configurations: first in a front seat configuration that was designed to prevent submarining, then in a rear seat configuration with adjusted spring stiffness to generate submarining. All subjects sustained extensive rib fractures from the shoulder belt loading. No pelvis fractures and no submarining were observed in the front seat configuration, but two subjects sustained lumbar vertebrae fractures. In the rear seat configuration, all subjects sustained pelvic fractures and demonstrated submarining. Corridors were constructed for the external forces and the PMHS kinematics. They are provided in this paper as new reference tests to assess the biofidelity of human surrogates in different configurations that either result in submarining or do not. In future, it is intended to analyze further seat and restraint system configurations to be able to define a submarining predictor.

  14. Speeding up biomolecular interactions by molecular sledding

    SciTech Connect

    Turkin, Alexander; Zhang, Lei; Marcozzi, Alessio; Mangel, Walter F.; Herrmann, Andreas; van Oijen, Antoine M.

    2015-10-07

    In numerous biological processes associations involve a protein with its binding partner, an event that is preceded by a diffusion-mediated search bringing the two partners together. Often hindered by crowding in biologically relevant environments, three-dimensional diffusion can be slow and result in long bimolecular association times. Moreover, the initial association step between two binding partners often represents a rate-limiting step in biotechnologically relevant reactions. We also demonstrate the practical use of an 11-a.a. DNA-interacting peptide derived from adenovirus to reduce the dimensionality of diffusional search processes and speed up associations between biological macromolecules. We functionalize binding partners with the peptide and demonstrate that the ability of the peptide to one-dimensionally diffuse along DNA results in a 20-fold reduction in reaction time. We also show that modifying PCR primers with the peptide sled enables significant acceleration of standard PCR reactions.

  15. Speeding up biomolecular interactions by molecular sledding

    DOE PAGES

    Turkin, Alexander; Zhang, Lei; Marcozzi, Alessio; ...

    2015-10-07

    In numerous biological processes associations involve a protein with its binding partner, an event that is preceded by a diffusion-mediated search bringing the two partners together. Often hindered by crowding in biologically relevant environments, three-dimensional diffusion can be slow and result in long bimolecular association times. Moreover, the initial association step between two binding partners often represents a rate-limiting step in biotechnologically relevant reactions. We also demonstrate the practical use of an 11-a.a. DNA-interacting peptide derived from adenovirus to reduce the dimensionality of diffusional search processes and speed up associations between biological macromolecules. We functionalize binding partners with the peptidemore » and demonstrate that the ability of the peptide to one-dimensionally diffuse along DNA results in a 20-fold reduction in reaction time. We also show that modifying PCR primers with the peptide sled enables significant acceleration of standard PCR reactions.« less

  16. Rocket Sled Propelled Testing of a Supersonic Inflatable Aerodynamic Decelerator

    NASA Technical Reports Server (NTRS)

    Meacham, Michael B.; Kennett, Andrew; Townsend, Derik J.; Marti, Benjamin

    2013-01-01

    Decelerators (IADs) have traditionally been tested in wind tunnels. As the limitations of these test facilities are reached, other avenues must be pursued. The IAD being tested is a Supersonic IAD (SIAD), which attaches just aft of the heatshield around the perimeter of an entry body. This 'attached torus' SIAD is meant to improve the accuracy of landing for robotic class missions to Mars and allow for potentially increased payloads. The SIAD Design Verification (SDV) test aims to qualify the SIAD by applying a targeted aerodynamic load to the vehicle. While many test architectures were researched, a rocket sled track was ultimately chosen to be the most cost effective way to achieve the desired dynamic pressures. The Supersonic Naval Ordnance Research Track (SNORT) at the Naval Air Warfare Center Weapons Division (NAWCWD) China Lake is a four mile test track, traditionally used for warhead and ejection seat testing. Prior to SDV, inflatable drag bodies have been tested on this particular track. Teams at Jet Propulsion Laboratory (JPL) and NAWCWD collaborate together to design and fabricate one of the largest sleds ever built. The SDV sled is comprised of three individual sleds: a Pusher Sled which holds the solid booster rockets, an Item Sled which supports the test vehicle, and a Camera Sled that is pushed in front for in-situ footage and measurements. The JPL-designed Test Vehicle has a full-scale heatshield shape and contains all instrumentation and inflation systems necessary to inflate and test a SIAD. The first campaign that is run at SNORT tested all hardware and instrumentation before the SIAD was ready to be tested. For each of the three tests in this campaign, the number of rockets and top speed was increased and the data analyzed to ensure the hardware is safe at the necessary accelerations and aerodynamic loads.

  17. Seasonal and diurnal melatonin production in exercising sled dogs.

    PubMed

    Dunlap, Kriya L; Reynolds, Arleigh J; Tosini, Gianluca; Kerr, Wendell W; Duffy, Lawrence K

    2007-08-01

    Melatonin is a hormone that is released from the pineal gland into the blood stream and is controlled by nerve impulses from the suprachiasmatic nuclei. Melatonin synthesis, which is inhibited by light on the mammalian retina, peaks in plasma concentrations during the night. Though still a subject of intense research, melatonin in mammals is known to effect the reproductive system, thyroid function, and adaptations to seasonal changes. Sled dogs in Fairbanks, Alaska (65 degrees N) can be exposed to anywhere from 21 h of daylight in the summer to 4 h in the winter. While light may be the primary factor influencing melatonin production, we hypothesized that exercise may also affect melatonin production. In the current study, sled dogs were used to study seasonal and diurnal variation in melatonin production. Sled dogs by nature are elite athletes and therefore exercise was a focus in the study. Both exercise and non exercise dogs from 2 distinct latitudes were used. The peak in melatonin production was prolonged in high latitude dogs (65 degrees N), compared with lower latitude dogs (45 degrees N). Dogs at both latitudes show a reduction in peak melatonin levels with exercise, and winter melatonin levels in both locations were higher than the summer. Surprisingly, sled dogs in Alaska had lower melatonin levels than sled dogs in New York.

  18. Prevalence of gastric lesions in racing Alaskan sled dogs.

    PubMed

    Davis, M S; Willard, M D; Nelson, S L; Mandsager, R E; McKiernan, B S; Mansell, J K; Lehenbauer, T W

    2003-01-01

    Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.

  19. 7. ROCKET SLED ON DECK OF TEST STAND 15. Photo ...

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

    7. ROCKET SLED ON DECK OF TEST STAND 1-5. Photo no. "6085, G-EAFB-16 SEP 52." Looking south to machine shop. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  20. Adjustable Shock Test Sled for Haversine Pulses at 250 fps

    SciTech Connect

    Hartwig, Troy; Hower, Brent; Seaholm, Aaron

    2007-11-08

    New test requirements were developed by Sandia National Laboratory to simulate a regime of shock testing not previously performed at the Kansas City Plant operated by Honeywell Federal Manufacturing & Technologies. These environments were unique in that they involved amplitude of shock >1000g with relatively long pulse durations (greater 5 ms but less than 10 ms) and involved velocity changes up to 235 ft/sec. Ten months were available to develop, design, manufacture and prove-in this new capability. We designed a new shock sled to deliver this new family of shock environments in a laboratory test. The performance range of the new sled includes five specific shocks (1000 g – 8 ms, 1300 - 6 ms, 1500 g – 5.4 ms, 1950 g – 6 ms, 2250 g – 5.4 ms; all haversine shaped), and it also incorporates adjustability to accommodate new shocks within this range. These shock environments result in velocity changes ranging from 160 fps to 250 fps. The test sled accommodates test articles weighing up to 20 lbs and measuring up to 10” along any axis.

  1. Sustained low-efficiency dialysis (SLED) for acute lithium intoxication

    PubMed Central

    Fiaccadori, Enrico; Maggiore, Umberto; Parenti, Elisabetta; Greco, Paolo; Cabassi, Aderville

    2008-01-01

    Acute lithium intoxication may cause serious neurologic and cardiac manifestations, up to the patient's death. Owing to its low molecular weight, relatively small volume of distribution close to that of total body water, and its negligible protein binding, lithium can be efficiently removed by any extracorporeal modality of renal replacement therapy (RRT). However, the shift from the intracellular to the extracellular compartment, with the inherent rebound phenomenon after the end of RRT, might limit the efficacy of the conventional, short-lasting haemodialysis. There have been no published studies up to now concerning the use of sustained low-efficiency dialysis (SLED) in lithium intoxication. This report describes a woman with a voluntary acute lithium ingestion of 40 tablets of lithium carbonate (8.12 mEq lithium each). The lithium concentration increased up to 4.18 mEq/l about 24 h after admission, notwithstanding treatment with intravenous crystalloids and gastric lavage. She developed mental status changes, oliguria, hypotension and bradycardia. We started SLED (8 h) with a blood flow of 200 ml/min and countercurrent dialysate flow of 300 ml/min. Lithium serum levels decreased by 86% during treatment, and the patient fully awoke recovering a normal mental status within the first 4 h of treatment. SLED was completed safely within the prescribed time. After the end of treatment, the rebound of lithium concentration was unremarkable. Renal function fully recovered, and the patient was transferred into a psychiatric facility 3 days after admission. PMID:25983926

  2. Sonic boom measurements from accelerating supersonic tracked sleds

    NASA Technical Reports Server (NTRS)

    Reed, J. W.

    1974-01-01

    Supersonic sled tests on the Sandia 1524-m (5000-ft) track generate sonic booms of sufficient intensity to allow some airblast measurements at distance scales not obtained from wind tunnel or flight tests. During acceleration, an emitted curved boom wave propagates to a caustic, or focus. Detailed measurements around these caustics may help to clarify the overpressure magnification which can occur from real aircraft operations. Six fixed pressure gages have been operated to document the general noise field, and a mobile array of twelve gages.

  3. Sea-Ice Thickness Monitoring from Sensor Equipped Inuit Sleds

    NASA Astrophysics Data System (ADS)

    Rodwell, Shane; Jones, Bryn; Wilkinson, Jeremy

    2013-04-01

    A novel instrumentation package capable of measuring sea-ice thickness autonomously has been designed for long-term deployment upon the dog drawn sleds of the indigenous peoples of the Arctic. The device features a range of sensors that have been integrated with an electromagnetic induction device. These include a global positioning system, temperature sensor, tilt meter and accelerometer. Taken together, this system is able to provide accurate (+/-5cm) measurements of ice thickness with spatio-temporal resolution ranging from 1m to 5m every second. Autonomous data transmission capability is provided via GSM, inspired by the fact that many of the coastal communities in Greenland possess modern cell-phone infrastructure, enabling an inexpensive means of data-retrieval. Such data is essential in quantifying the sea-ice mass balance; given that existing satellite based systems are unable to measure ice-thickness directly. Field-campaign results from a prototype device, deployed in the North West of Greenland during three consecutive seasons, have demonstrated successful proof-of-concept when compared to data provided by ice mass balance (IMB) stations provided at fixed positions along the route of the sled. This project highlights not only the use of novel polar technology, but how opportunistic deployment using an existing roving platform (Inuit sledges) can provide economical, yet highly valuable, data for instrumentation development.

  4. Racing Alaskan sled dogs as a model of "ski asthma".

    PubMed

    Davis, Michael S; McKiernan, Brendan; McCullough, Sheila; Nelson, Stuart; Mandsager, Ronald E; Willard, Michael; Dorsey, Karen

    2002-09-15

    Athletes who play sports in cold weather, particularly skaters and cross-country skiers, have an increased prevalence of lower airway disease that is hypothesized to result from repeated penetration of incompletely conditioned air into the lung periphery. In this study, we investigated the hypothesis that canine winter athletes also suffer from increased prevalence of lung disease secondary to hyperpnea with cold air. Bronchoscopy and bronchoalveolar lavage was conducted in elite racing sled dogs 24 to 48 hours after completion of a 1,100-mile endurance race. Bronchoscopic abnormalities were classified as none, mild, moderate, or severe, based on the quantity and distribution of intralumenal debris. Eighty-one percent of the dogs (48 of 59) examined had abnormal accumulations of intralumenal debris, with 46% (27 of 59) classified as moderate or severe, indicating significant accumulation of exudate. Bronchoalveolar lavage obtained from dogs after the race had significantly higher nucleated macrophage and eosinophil counts compared with sedentary control dogs. Our findings support the hypothesis that strenuous exercise in cold environments can lead to lower airway disease and suggest that racing sled dogs may be a useful naturally occurring animal model of the analogous human disease.

  5. Evaluation of plasma inflammatory cytokine concentrations in racing sled dogs.

    PubMed

    von Pfeil, Dirsko J F; Cummings, Bethany P; Loftus, John P; Levine, Corri B; Mann, Sabine; Downey, Robert L; Griffitts, Caroline; Wakshlag, Joseph J

    2015-12-01

    In human athletes significant changes in cytokine concentrations secondary to exercise have been observed. This prospective study evaluated the effect of a multi-day stage sled dog race on plasma concentrations of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-10 (IL-10). Samples from 20 dogs were harvested prior to and on days 2 and 8 of an 8-day race. Exercise resulted in significantly decreased TNF-α and IL-8 as well as increases of MCP-1, IL-6, and IL-10 concentrations (P-value between 0.01 and < 0.0001 for all parameters). The proportion of values for IL-2 that were below the detection limit increased from 40% on day 0 to 75% on day 2 and decreased on day 8 to 40% (P = 0.04). Racing sled dogs show cytokine-concentration changes that are different from those in humans.

  6. Evaluation of plasma inflammatory cytokine concentrations in racing sled dogs

    PubMed Central

    von Pfeil, Dirsko J. F.; Cummings, Bethany P.; Loftus, John P.; Levine, Corri B.; Mann, Sabine; Downey, Robert L.; Griffitts, Caroline; Wakshlag, Joseph J.

    2015-01-01

    In human athletes significant changes in cytokine concentrations secondary to exercise have been observed. This prospective study evaluated the effect of a multi-day stage sled dog race on plasma concentrations of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-10 (IL-10). Samples from 20 dogs were harvested prior to and on days 2 and 8 of an 8-day race. Exercise resulted in significantly decreased TNF-α and IL-8 as well as increases of MCP-1, IL-6, and IL-10 concentrations (P-value between 0.01 and < 0.0001 for all parameters). The proportion of values for IL-2 that were below the detection limit increased from 40% on day 0 to 75% on day 2 and decreased on day 8 to 40% (P = 0.04). Racing sled dogs show cytokine-concentration changes that are different from those in humans. PMID:26663920

  7. Athletic heart syndrome in dogs competing in a long-distance sled race.

    PubMed

    Constable, P D; Hinchcliff, K W; Olson, J; Hamlin, R L

    1994-01-01

    The cardiac effects of endurance training were evaluated by cardiac auscultation and electrocardiographic examination of 48 heavily trained sled dogs (3,000-5,000 km of training), 18 lightly trained sled dogs (300-800 km of training), 19 untrained sled dogs, and 14 mongrel dogs. A grade I-II/VI early- to midsystolic cardiac murmur was auscultated with increasing frequency as training level increased. The QRS duration (66.1 +/- 7.4 ms) and QT interval (236 +/- 20 ms) were significantly (P < 0.05) longer in heavily trained sled dogs than in mongrel dogs (QRS, 60.6 +/- 4.6; QT, 219 +/- 11 ms). A long QT interval (> 250 ms) was observed in 8 (16.7%) heavily trained dogs but not in the other groups. A significant rightward shift in the mean electrical axis of ventricular depolarization in the frontal plane was observed in heavily trained sled dogs. The auscultatory and electrocardiographic findings in heavily trained sled dogs were remarkably similar to those reported in elite human endurance athletes, suggesting that endurance-trained sled dogs provide a naturally occurring model for the athletic heart syndrome.

  8. Development of new S-band SLED for PAL-XFEL Linac

    NASA Astrophysics Data System (ADS)

    Joo, Youngdo; Park, Yongjung; Heo, Hoon; Heo, Jinyul; Park, Sung-Soo; Kim, Sang-Hee; Kim, Kwang-Hoon; Kang, Heung-Sik; Lee, Heung-Soo; Noh, Sungju; Oh, Kyoungmin

    2017-01-01

    In order to achieve beam acceleration to the beam energy of 10 GeV at the end of its 716 m-long linear accelerator (Linac), the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) is going to operate the Stanford Linear Accelerator Energy Doubler (SLED) at the maximum klystron output peak power of 80 MW, with a pulse length of 4 μs, and at a repetition rate of 60 Hz. The original SLED that had been used in Pohang Light Source-II (PLS-II) can no longer sustain such a high-power operation because excessive radiation caused by RF breakdown has been frequently detected even at the lower klystron peak power during the PLS-II operation. Therefore, a new SLED is designed by modifying both the 3-dB power hybrid and the waveguide-cavity coupling structure of the original SLED where the excessive radiation has been mainly detected. The finite-difference time-domain (FDTD) simulation in the CST Microwave Studio shows that the new SLED has a peak electric field and a surface current lower than those of the original SLED at the same level of the RF input peak power, which would secure stable high-power operation. All of the 42 SLEDs in the PAL-XFEL Linac are newly fabricated and installed. During the RF conditioning of the PAL-XFEL Linac, no significant vacuum and radiation issue was found in the new SLEDs. Finally, the accelerated electron beam energy of 10 GeV obtained at the end of the PAL-XFEL Linac verified that the RF performance of the new SLED is stable.

  9. Dynamic Analysis of a Sled Traveling Along a Rough Rail.

    DTIC Science & Technology

    2014-09-26

    determine if this prnfile cnuld excite the fundamental resonances of he ! sled . This resulted in a directive tn perform add i t inna I cnnputer s...th cmpared t tw rough T3 34000 ail (an S rf ~y,x 0.01? inches versus 0.043 inches). In addition, the south 150, 1 feet of rail trp had t he same...r f sa i L f~ctn 1~ r ~ med mijt er I aIs ~f th ne p u f, i . .yp;> y, I~ ;. W Wh en sli pp agSe does -ccur, t he t A r e ria fr. k! t ranr)s m i ted

  10. Responses of side impact dummies in sled tests.

    PubMed

    Yoganandan, Narayan; Pintar, Frank A

    2005-05-01

    Sled tests were conducted at a velocity of 6.7 m/s using side impact dummies (SID, BioSID, ES-2, and WorldSIDp) and the resulting biomechanical responses were compared with responses from post mortem human subjects (PMHS). Initial impact conditions were with and without pelvic offset in combination with and without padding on the impacting wall. Impact forces, thoracic trauma index, chest compression, and viscous criteria were evaluated. The probability of injury was estimated and rates of deformation were computed for each body region. Dummy responses were not always similar in terms of trend and injury criteria when compared with PMHS tests under the same initial conditions. Response variations will be of value in improving the biofidelity characteristics of dummies for crashworthiness evaluations.

  11. Muscle plasticity of Inuit sled dogs in Greenland.

    PubMed

    Gerth, Nadine; Sum, Steffen; Jackson, Sue; Starck, J Matthias

    2009-04-01

    This study examined flexible adjustments of skeletal muscle size, fiber structure, and capillarization in Inuit sled dogs responding to seasonal changes in temperature, exercise and food supply. Inuit dogs pull sleds in winter and are fed regularly throughout this working season. In summer, they remain chained to rocks without exercise, receiving food intermittently and often fasting for several days. We studied two dog teams in Northern Greenland (Qaanaaq) where dogs are still draught animals vital to Inuit hunters, and one dog team in Western Greenland (Qeqertarsuaq) where this traditional role has been lost. Northern Greenland dogs receive more and higher quality food than those in Western Greenland. We used ultrasonography for repeated muscle size measurements on the same individuals, and transmission electron microscopy on micro-biopsies for summer-winter comparisons of muscle histology, also within individuals. At both study sites, dogs' muscles were significantly thinner in summer than in winter - atrophy attributable to reduced fiber diameter. Sarcomeres from West Greenland dogs showed serious myofilament depletion and expansion of the sarcoplasmatic space between myofibrils during summer. At both study sites, summer samples showed fewer interfibrillar and subsarcolemmal mitochondria, and fewer lipid droplets between myofibrils, than did winter samples. In summer, capillary density was higher and inter-capillary distance smaller than in winter, but the capillary-to-fiber-ratio and number of capillaries associated with single myofibers were constant. Increased capillary density was probably a by-product of differential tissue responses to condition changes rather than a functional adaptation, because thinning of muscle fibers in summer was not accompanied by reduction in the capillary network. Thus, skeletal muscle of Inuit dogs responds flexibly to changes in functional demands. This flexibility is based on differential changes in functional components

  12. Driven microswimmers on a 2D substrate: A stochastic towed sled model

    SciTech Connect

    Marchegiani, Giampiero; Marchesoni, Fabio

    2015-11-14

    We investigate, both numerically and analytically, the diffusion properties of a stochastic sled sliding on a substrate, subject to a constant towing force. The problem is motivated by the growing interest in controlling transport of artificial microswimmers in 2D geometries at low Reynolds numbers. We simulated both symmetric and asymmetric towed sleds. Remarkable properties of their mobilities and diffusion constants include sidewise drifts and excess diffusion peaks. We interpret our numerical findings by making use of stochastic approximation techniques.

  13. Very-Heavy Sled Training for Improving Horizontal Force Output in Soccer Players.

    PubMed

    Morin, Jean-Benoît; Petrakos, George; Jimenez-Reyes, Pedro; Brown, Scott R; Samozino, Pierre; Cross, Matt R

    2016-11-11

    Sprint running acceleration is a key feature of physical performance in team sports, and recent literature shows that the ability to generate large magnitudes of horizontal ground reaction force and mechanical effectiveness of force application are paramount. We tested the hypothesis that very-heavy loaded sled sprint training would induce an improvement in horizontal force production, via an increased effectiveness of application. Training-induced changes in sprint performance and mechanical outputs were computed using a field method based on velocity-time data, before and after an 8-week protocol (16 sessions of 10x20-m sprints). 16 male amateur soccer players were assigned to either a very-heavy sled (80% body-mass sled load) or a control group (unresisted sprints). The main outcome of this pilot study is that very-heavy sled resisted sprint training, using much greater loads than traditionally recommended, clearly increased maximal horizontal force production compared to standard unloaded sprint training (effect size of 0.80 vs 0.20 for controls, unclear between-group difference) and mechanical effectiveness (i.e. more horizontally applied force; effect size of 0.95 vs -0.11, moderate between-group difference). In addition, 5-m and 20-m sprint performance improvement were moderate and small for the very-heavy sled group, and small and trivial for the control group, respectively. This brief report highlights the usefulness of very-heavy sled (80% body-mass) training, which may suggest value for practical improvement of mechanical effectiveness and maximal horizontal force capabilities in soccer players and other team sport athletes. This study may encourage further research to confirm the usefulness of very-heavy sled in this context.

  14. Diet of Racing Sled Dogs Affects Erythrocyte Depression by Stress

    PubMed Central

    Adkins, T. O.; Kronfeld, D. S.

    1982-01-01

    Fourteen racing huskies were matched into pairs then assigned to two diets, a commercial stress diet and an experimental diet. Proportions of protein: fat:carbohydrate on an available energy basis were 23:57:20 in a commercial stress diet and 28:69:3 in an experimental diet. The team participated in the 1979 Iditarod Trail race and was overtaken by an episode of diarrhea. Clinical signs were suggestive of parvovirus infection; high serum titers of parvo antibodies were found after the race. Blood examination showed normal levels of metabolites, electrolytes and enzymes after the race. Erythrocyte counts were depressed significantly during the race, by 15% in dogs fed an experimental diet and by 27% in those fed a commercial stress diet. Erythrocyte parameters have also become depressed during the racing season in middle distance sled dogs fed 28% protein (energy basis) but not 32 or 39%. Depressed red blood cell production has been demonstrated previously in dogs subjected to stress induced experimentally in several ways, and its restoration has been affected by dietary protein. Erythrocyte parameters may be useful indicies of the degree of stress in a dog as well as the adequacy of its protein intake during stress. PMID:17422178

  15. Effects of resisted sled towing on sprint kinematics in field-sport athletes.

    PubMed

    Lockie, Robert G; Murphy, Aron J; Spinks, Christopher D

    2003-11-01

    Weighted sled towing is a common resisted sprint training technique even though relatively little is known about the effects that such practice has on sprint kinematics. The purpose of this study was to explore the effects of sled towing on acceleration sprint kinematics in field-sport athletes. Twenty men completed a series of sprints without resistance and with loads equating to 12.6 and 32.2% of body mass. Stride length was significantly reduced by approximately 10 and approximately 24% for each load, respectively. Stride frequency also decreased, but not to the extent of stride length. In addition, sled towing increased ground contact time, trunk lean, and hip flexion. Upper-body results showed an increase in shoulder range of motion with added resistance. The heavier load generally resulted in a greater disruption to normal acceleration kinematics compared with the lighter load. The lighter load is likely best for use in a training program.

  16. Determining the optimal load for resisted sprint training with sled towing.

    PubMed

    Alcaraz, Pedro E; Palao, José Manuel; Elvira, José L L

    2009-03-01

    An excessive load in resisted sprint training can produce changes in running patterns. Therefore, load control is essential to ensure the specificity of these training methods. The most common way to control it is through the percentage of velocity lost in relation to maximum velocity. The present paper describes a study that aimed to establish the load for sprint training with sled towing. The study developed a regression equation for calculating the load in the maximum velocity phase. The calculation was done with 26 athletes from the Spanish and French national levels on a synthetic track surface and with spikes. The regression equation obtained was % body mass = (-0.8674 x % velocity) + 87.99. The equation, although specific for type of surface used and sled towing characteristics, is useful in establishing the optimal load for acceleration and maximum velocity training with sled towing.

  17. Switching speed effect of phase shift keying in SLED for generating high power microwaves

    NASA Astrophysics Data System (ADS)

    Xiong, Zheng-Feng; Cheng, Cheng; Yu, Jian; Chen, Huai-Bi; Ning, Hui

    2016-01-01

    SLAC energy doubler (SLED) type radio-frequency pulse compressors are widely used in large-scale particle accelerators for converting long-duration moderate-power input pulses into short-duration high-power output pulses. Phase shift keying (PSK) is one of the key components in SLED pulse compression systems. Performance of the PSK will influence the output characteristics of the SLED, such as the rise-time of the output pulse, maximal peak power gain, and energy efficiency. In this paper, a high power microwave source based on power combining and pulse compression of conventional klystrons is introduced. The effects of nonideal PSK with slow switching speed and PSK without power output during the switching process are investigated, and the experimental results with nonideal PSK agree well with the analytical results.

  18. Simultaneous processing of photographic and accelerator array data from sled impact experiment

    NASA Astrophysics Data System (ADS)

    Ash, M. E.

    1982-12-01

    A Quaternion-Kalman filter model is derived to simultaneously analyze accelerometer array and photographic data from sled impact experiments. Formulas are given for the quaternion representation of rotations, the propagation of dynamical states and their partial derivatives, the observables and their partial derivatives, and the Kalman filter update of the state given the observables. The observables are accelerometer and tachometer velocity data of the sled relative to the track, linear accelerometer array and photographic data of the subject relative to the sled, and ideal angular accelerometer data. The quaternion constraints enter through perfect constraint observations and normalization after a state update. Lateral and fore-aft impact tests are analyzed with FORTRAN IV software written using the formulas of this report.

  19. Space Sled--a device for the investigation of the physiological effects of weightlessness.

    PubMed

    Harry, N A; Benson, A J

    1989-01-01

    Space Sled is a device for providing controlled linear acceleration stimuli in the microgravity environment of orbital flight. The scientific objectives of the experiments which used Space Sled on the D-1 Spacelab mission were to study aspects of otolith organ (that is, that part of the inner ear which transduces linear accelerations) function and adaptation in weightlessness. Space Sled comprises electrical and mechanical sub-systems. The latter is made up of a carriage running on twin rails that are fixed to the floor of Spacelab. The assembly is 6 m long with a working section of 3.5 m. The seat accommodating the test subject can be mounted on the carriage in any of three orthogonal positions. The carriage is coupled by a flexible steel cable to a servo-controlled electric motor which is capable of producing a peak acceleration of 2 m/s2 and peak velocity of 2.4 m/s. In the event of failure of comprehensive safety circuits in the electrical sub-system, a mechanical snubber, of crushable honeycomb construction, limits the deceleration to 20 m/s2. Mechanical structures providing carriage guidance, Sled/Spacelab interfaces, carriage latching, motor mounting and cable tensioning are detailed in the paper.

  20. Effect of the coefficient of friction of a running surface on sprint time in a sled-towing exercise.

    PubMed

    Linthorne, Nicholas P; Cooper, James E

    2013-06-01

    This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (micro = 0.21-0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient offriction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected.

  1. Head Trajectories of Restrained Child Dummy in Sled Tests Over 56 kph Delta-V

    PubMed Central

    Hauschild, Hans W.

    2000-01-01

    Child restraint devices (CRDs) have been used for many years to protect children in automotive crashes. The following data was collected to find out whether current restraints would be able to pass more stringent dynamic testing at higher changes in velocity (delta-v), such as the NHTSA NCAP program or the IIHS offset barrier test, and to look at one possible misuse mode. Three basic types of CRDs were sled tested at a delta-v between 57.5 & 61.4 kph (35.7 & 38.1 mph). Data from each test are presented and compared. Comparisons are made between each seat’s sled test results and various countries’ standards. PMID:11558089

  2. Performance evaluation of child safety seats in far-side lateral sled tests at varying speeds.

    PubMed

    Ghati, Yoganand; Menon, Rajiv A; Milone, Mary; Lankarani, Hamid; Oliveres, Gerardo

    2009-10-01

    Protection of children in Child Safety Seats (CSS) in side impact crashes has been a topic of recent studies. The objective of this study was to evaluate the performance of CSS in far-side impacts through a series of sled tests conducted at varying test speeds. Forty eight sled tests were conducted at three speeds (24 km/h, 29 km/h and 36 km/h), under two different CSS attachment conditions (LATCH and seat belt attached), using rear facing and forward facing CSS from four different manufacturers. Analyses were conducted to examine head retention within the CSS, velocity of the head as it passes an imaginary plane (cross over into other occupant space or door), lateral trajectory of the head and knee; head, chest and pelvis accelerations; neck and lumbar loads and moments. In addition to these parameters, the CSS were visually inspected for structural integrity after each test. Results from these sled tests highlighted the differential performance of CSS in far-side impacts. During the tests, all CSS experienced significant lateral movement irrespective of attachment type. In rear facing CSS tests, one of the designs failed as the seat disengaged from its base. In forward facing CSS tests, it was observed that the seat belt attached CSS experienced less rotational motion than the LATCH attached CSS. ATD head retention within the seat was not achieved with either CSS attachments at any speed. The findings from this study augment the current efforts to define regulatory sled setup procedure for far-side impact crashes involving children in CSS, which currently does not exist and will eventually further the protection of children in automobiles.

  3. Head injuries in winter sports: downhill skiing, snowboarding, sledding, snowmobiling, ice skating and ice hockey.

    PubMed

    Chaze, Brian; McDonald, Patrick

    2009-02-01

    Winter sports are often associated with high speed, which carries with it the potential for collision. As such, head injuries are among the more commonly encountered injuries in winter-related sporting activities. This article focuses on popular winter sports such as downhill skiing and snowboarding, sledding, snowmobiling, ice skating, and hockey. In virtually all of these activities, the incidence and severity of head injuries can be reduced by the use of appropriate protective headgear.

  4. Head injuries in winter sports: downhill skiing, snowboarding, sledding, snowmobiling, ice skating and ice hockey.

    PubMed

    Chaze, Brian; McDonald, Patrick

    2008-02-01

    Winter sports are often associated with high speed, which carries with it the potential for collision. As such, head injuries are among the more commonly encountered injuries in winter-related sporting activities. This article focuses on popular winter sports such as downhill skiing and snowboarding, sledding, snowmobiling, ice skating, and hockey. In virtually all of these activities, the incidence and severity of head injuries can be reduced by the use of appropriate protective headgear.

  5. Simultaneous Processing of Photographic and Accelerometer Array Data from Sled Impact Experiments,

    DTIC Science & Technology

    1982-12-01

    differential equations solutions rather than more sophisticated integration techniques because the spacing between observation times tk and tk+l is of...FOR ROTATIONS. ......... 24 2.1 Quaternion Algebra....................24 2.2 Rotations in 3- Space .................26 2.3 Correspondence with Matrices...coordinates of fiducial irelative to sled frame at time t F nonlinear state transition function g acceleration due to gravity (980.3 cm/s 2) H nonlinear

  6. Kinematic, strength, and stiffness adaptations after a short-term sled towing training in athletes.

    PubMed

    Alcaraz, P E; Elvira, J L L; Palao, J M

    2014-04-01

    One of the most frequently used methods for training the sprint-specific strength is the sled towing. To date, no studies have been conducted to explore the effects of this method after a training period in well-trained athletes. The purpose of this study was to determine the effects of 4 weeks of resisted sprint training with sled towing. Twenty-two trained athletes experienced in the use of weighted sled (WS) participated in the study. They conducted the same 3-week training to level their initial condition. After that they were distributed in two groups, unresisted (UR) and WS training. They carried out the same 4-week, 2 days/week sprint-specific training, only differing in that the experimental group performed sprints with a (WS) which caused a reduction of 7.5% of their maximum velocity. Pre- and posttest were conducted which included the measurement of sprint kinematics, muscular strength (including isoinertial, isokinetic, and jump measurements), and sprinting stiffness (leg and vertical). Results show different adaptations in the groups although no interaction effect was found. The WS group improved the velocity in the transition phase, while the UR group improved the velocity in the maximum velocity phase. No improvements in the height of the jump tests were found.

  7. Validation of the advanced dynamic anthropomorphic manikin (ADAM) database: horizontal sled test.

    PubMed

    Banks, D; Obergefell, L; Rizer, A

    1997-01-01

    As the U.S. Air Force (USAF) continues to introduce advanced technology to make its planes more dynamic, it is becoming increasingly more difficult to adequately test the systems to ensure pilot safety. A cost effective solution to this problem is the use of computer modeling to augment testing. The accuracy of such computer modeling depends on the validity of the analytical formulation, and the correctness of the database characterizing the systems being modeled. One such database is for the large Advanced Dynamic Anthropomorphic Manikin (ADAM); a human surrogate developed by the USAF for high speed ejection testing. The database is used in the Articulated Total Body (ATB) computer model utilized by the Armstrong Laboratories to predict human body dynamics during aircraft crashes and emergency escapes. The large ADAM database, and the parameters from a horizontal sled test were used in an ATB sled simulation. The results of the ATB simulation are compared with actual sled test data. These results include head, chest, and pelvis accelerations; neck and lumbar loads; and elbow, knee, hip and shoulder angular motion. The comparisons are the basis for validating the ADAM database for future predictive simulations.

  8. Effect of endurance training on cardiac morphology in Alaskan sled dogs.

    PubMed

    Stepien, R L; Hinchcliff, K W; Constable, P D; Olson, J

    1998-10-01

    The cardiac morphology of 77 conscious Alaskan sled dogs before and after 5 mo of endurance training (20 km/day team pulling a sled and musher) was studied using two-dimensional and M-mode echocardiography. Subgroups included dogs with at least one season of previous training ("veterans") and dogs undergoing their first season of training ("rookies"). Training resulted in a significant (P < 0.05) decrease in resting heart rate (-15%) and significant increases in interventricular septal thickness (systole, 15%; diastole, 13%), left ventricular (LV) internal dimension in diastole (LVIDd, 4%), LV free wall thickness in systole (9%) and diastole (LVWd, 9%), and left atrial diameter (5%) in all dogs, but the increase in LVWd was greater in rookies (16%) than in veterans (7%). Training increased end-diastolic volume index (8%), LV mass index (24%), and heart weight index (24%) and decreased the LVIDd-to-LVWd ratio (-6%) but did not alter cardiac index. We conclude that increased LV mass attributable to LV dilation and hypertrophy is associated with endurance training in Alaskan sled dogs. Disproportionate LV wall thickening accompanying LV dilation suggests that cardiac morphological changes are due to volume and pressure loading. These training-induced changes are similar to those documented in human athletes undergoing combined isometric and isotonic training and differ from studies of dogs trained on treadmills.

  9. High-power rf pulse compression with SLED-II at SLAC

    SciTech Connect

    Nantista, C.; Kroll, N.M.; Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Ruth, R.D.; Tantawi, S.G.; Vlieks, A.E.; Wilson, P.B.

    1993-04-01

    Increasing the peak rf power available from X-band microwave tubes by means of rf pulse compression is envisioned as a way of achieving the few-hundred-megawatt power levels needed to drive a next-generation linear collider with 50--100 MW klystrons. SLED-II is a method of pulse compression similar in principal to the SLED method currently in use on the SLC and the LEP injector linac. It utilizes low-los resonant delay lines in place of the storage cavities of the latter. This produces the added benefit of a flat-topped output pulse. At SLAC, we have designed and constructed a prototype SLED-II pulse-compression system which operates in the circular TE{sub 01} mode. It includes a circular-guide 3-dB coupler and other novel components. Low-power and initial high-power tests have been made, yielding a peak power multiplication of 4.8 at an efficiency of 40%. The system will be used in providing power for structure tests in the ASTA (Accelerator Structures Test Area) bunker. An upgraded second prototype will have improved efficiency and will serve as a model for the pulse compression system of the NLCTA (Next Linear Collider Test Accelerator).

  10. Mercury interferes with endogenous antioxidant levels in Yukon River subsistence-fed sled dogs

    NASA Astrophysics Data System (ADS)

    Dunlap, Kriya L.; Reynolds, Arleigh J.; Gerlach, S. Craig; Duffy, Lawrence K.

    2011-10-01

    Before adopting modern corn-and-grain-based western processed diets, circumpolar people had a high fat and protein subsistence diet and exhibited a low incidence of obesity, diabetes and cardiovascular disease. Some health benefits are attributable to a subsistence diet that is rich in omega-3 fatty acids and antioxidants. Pollution, both global and local, is a threat to wild foods, as it introduces contaminants into the food system. Northern indigenous people and their sled dogs are exposed to a variety of contaminants, including mercury, that accumulate in the fish and game that they consume. The sled dogs in Alaskan villages are maintained on the same subsistence foods as their human counterparts, primarily salmon, and therefore they can be used as a food systems model for researching the impact of changes in dietary components. In this study, the antioxidant status and mercury levels were measured for village sled dogs along the Yukon River. A reference kennel, maintained on a nutritionally balanced commercial diet, was also measured for comparison. Total antioxidant status was inversely correlated with the external stressor mercury.

  11. Upgrade of the SLAC SLED II Pulse Compression System Based on Recent High Power Tests

    SciTech Connect

    Vlieks, A.E.; Fowkes, W.R.; Loewen, R.J.; Tantawi, S.G.; /SLAC

    2011-09-06

    In the Next Linear Collider (NLC) it is expected that the high power rf components be able to handle peak power levels in excess of 400 MW. We present recent results of high power tests designed to investigate the RF breakdown limits of the X-band pulse compression system used at SLAC. (SLED-II). Results of these tests show that both the TE{sub 01}-TE{sub 10} mode converter and the 4-port hybrid have a maximum useful power limit of 220-250 MW. Based on these tests, modifications of these components have been undertaken to improve their peak field handling capability. Results of these modifications will be presented. As part of an international effort to develop a new 0.5-1.5 TeV electron-positron linear collider for the 21st century, SLAC has been working towards a design, referred to as 'The Next Linear Collider' (NLC), which will operate at 11.424 GHz and utilize 50-75 MW klystrons as rf power sources. One of the major challenges in this design, or any other design, is how to generate and efficiently transport extremely high rf power from a source to an accelerator structure. SLAC has been investigating various methods of 'pulse compressing' a relatively wide rf pulse ({ge} 1 {mu}s) from a klystron into a narrower, but more intense, pulse. Currently a SLED-II pulse compression scheme is being used at SLAC in the NLC Test Accelerator (NLCTA) and in the Accelerator Structures Test Area (ASTA) to provide high rf power for accelerator and component testing. In ASTA, a 1.05 {mu}s pulse from a 50 MW klystron was successfully pulse compressed to 205 MW with a pulse width of 150 ns. Since operation in NLC will require generating and transporting rf power in excess of 400 MW it was decided to test the breakdown limits of the SLED-II rf components in ASTA with rf power up to the maximum available of 400 MW. This required the combining of power from two 50 MW klystrons and feeding the summed power into the SLED-II pulse compressor. Results from this experiment demonstrated

  12. Impact of Harness Attachment Point on Kinetics and Kinematics During Sled Towing.

    PubMed

    Bentley, Ian; Atkins, Steve J; Edmundson, Christopher J; Metcalfe, John; Sinclair, Jonathan K

    2016-03-01

    Resisted sprint training is performed in a horizontal direction and involves similar muscles, velocities, and ranges of motion (ROM) to those of normal sprinting. Generally, sleds are attached to the athletes through a lead (3 m) and harness; the most common attachment points are the shoulder or waist. At present, it is not known how the different harness point's impact on the kinematics and kinetics associated with sled towing (ST). The aim of the current investigation was to examine the kinetics and kinematics of shoulder and waist harness attachment points in relation to the acceleration phase of ST. Fourteen trained men completed normal and ST trials, loaded at 10% reduction of sprint velocity. Sagittal plane kinematics from the trunk, hip, knee, and ankle were measured, together with stance phase kinetics (third footstrike). Kinetic and kinematic parameters were compared between harness attachments using one-way repeated-measures analysis of variance. The results indicated that various kinetic differences were present between the normal and ST conditions. Significantly greater net horizontal mean force, net horizontal impulses, propulsive mean force, and propulsive impulses were measured (p < 0.05). Interestingly, the waist harness also led to greater net horizontal impulse when compared with the shoulder attachment (p < 0.001). In kinematic terms, ST conditions significantly increased peak flexion in hip, knee, and ankle joints compared with the normal trials (p < 0.05). Results highlighted that the shoulder harness had a greater impact on trunk and knee joint kinematics when compared with the waist harness (p < 0.05). In summary, waist harnesses seem to be the most suitable attachment point for the acceleration phase of sprinting. Sled towing with these attachments resulted in fewer kinematic alterations and greater net horizontal impulse when compared with the shoulder harness. Future research is necessary in order to explore the long-term adaptations of

  13. Efficacy of omeprazole for the prevention of exercise-induced gastritis in racing Alaskan sled dogs.

    PubMed

    Davis, M S; Willard, M D; Nelson, S L; McCullough, S M; Mandsager, R E; Roberts, J; Payton, M E

    2003-01-01

    Exercise-induced gastritis and gastric ulcers are common in humans and horses, and recently have been described in racing sled dogs. The cause of exercise-induced gastric disease is not completely understood in any species, but pharmacologic suppression of acid secretion is an effective treatment in humans and horses. Thus, we tested the hypothesis that omeprazole, a proton-pump inhibitor shown to reduce gastric acid secretion in dogs, would reduce the severity of exercise-induced gastric disease. Three teams of 16 dogs each competing in the 2002 Iditarod Sled Dog Race were recruited for participation. Within each team, dogs were randomly assigned to either treatment (20 mg omeprazole PO q24h) or placebo. Treatments were administered until either completion of the race or withdrawal of an individual dog from competition. Gastric endoscopy was performed in all dogs 24 hours after completion or withdrawal, and the gastric mucosa was scored by using a subjective severity score (0 = normal, 3 = numerous bleeding ulcers). Treatment with omeprazole significantly reduced mean gastricseverity score compared to placebo (omeprazole: 0.65 +/- 0.17, placebo: 1.09 +/- 0.18; P = .028), but also was associated with increased frequency of diarrhea during the race (omeprazole 54%, placebo 21%; P = .017). Examination of our data suggests that omeprazole may be an effective treatment for exercise-induced gastric disease in racing sled dogs. However, further investigation regarding the cause and clinical relevance of diarrhea associated with omeprazole treatment must be conducted before omeprazole can be recommended for routine prophylactic treatment in these athletes.

  14. Technical Advisory Team (TAT) report on the rocket sled test accident of October 9, 2008.

    SciTech Connect

    Stofleth, Jerome H.; Dinallo, Michael Anthony; Medina, Anthony J.

    2009-01-01

    This report summarizes probable causes and contributing factors that led to a rocket motor initiating prematurely while employees were preparing instrumentation for an AIII rocket sled test at SNL/NM, resulting in a Type-B Accident. Originally prepared by the Technical Advisory Team that provided technical assistance to the NNSA's Accident Investigation Board, the report includes analyses of several proposed causes and concludes that the most probable source of power for premature initiation of the rocket motor was the independent battery contained in the HiCap recorder package. The report includes data, evidence, and proposed scenarios to substantiate the analyses.

  15. Rail Roughness Study of the Holloman High Speed Rocket Sled Test Track

    DTIC Science & Technology

    1981-09-01

    Test Track My7 6585h Tet Grup (FS .AND t .8A & WORK UHIWT NUMBER II. ~ ~ ~ ~~ 1 CONTROLLINR OFIENM N0DRS C55harTes Group aFS TK 9. DISTRIUTIORNSTATMT...Speed Rocket Sled Test Track. Results of the study will be used to: 1.1.1 Provide forcing functions for Sledyne, a computer simulation program for...one foot intervals along the track. This rationale was justified by the fact that the slope would 3Awkw provide only low frequency forcing functions

  16. In-vivo Kinematics of the Cervical Spine in Frontal Sled Tests

    PubMed Central

    Dehner, Christoph; Schick, Sylvia; Hell, Wolfram; Richter, Peter; Kraus, Michael; Kramer, Michael

    2013-01-01

    The description of cervical spine motion and the risk to sustain a cervical spine injury in traffic accidents is mainly based on rear-end collisions. The knowledge about frontal collisions is comparable low. Therefore the objective of this exploratory study was, to describe the in-vivo cervical spine motion and acceleration during simulated frontal sled collisions and to identify sequences of motion in which the risk of injury is increased. A frontal collision with a speed change of 10.2km/h was simulated in a sled test with ten volunteers. Cervical spine kinematics was assessed by the simultaneous analysis of the angular head motion and acceleration as well as the simultaneous analysis of the relative motion and acceleration between the head and the first thoracic vertebral body. The motion sequence was divided into five phases. The combination of peak values of the angular head acceleration to ventral and the relative horizontal head acceleration to dorsal between the time period of 90ms and 110ms (early flexion phase) included – potential injury generating – shear forces. Although a hyperflexion (late rebound phase) as injury pattern didn’t occur, dorsal soft tissue injuries due to eccentric muscle-sprain could not be ruled out completely. In conclusion the study showed under simulated test conditions that during the early flexion phase and the late rebound phase, acceleration and movement pattern occur that could lead to cervical spine injuries. PMID:23618481

  17. Impact response of restrained PMHS in frontal sled tests: skeletal deformation patterns under seat belt loading.

    PubMed

    Shaw, Greg; Parent, Dan; Purtsezov, Sergey; Lessley, David; Crandall, Jeff; Kent, Richard; Guillemot, Herve; Ridella, Stephen A; Takhounts, Erik; Martin, Peter

    2009-11-01

    This study evaluated the response of restrained post-mortem human subjects (PMHS) in 40 km/h frontal sled tests. Eight male PMHS were restrained on a rigid planar seat by a custom 3-point shoulder and lap belt. A video motion tracking system measured three-dimensional trajectories of multiple skeletal sites on the torso allowing quantification of ribcage deformation. Anterior and superior displacement of the lower ribcage may have contributed to sternal fractures occurring early in the event, at displacement levels below those typically considered injurious, suggesting that fracture risk is not fully described by traditional definitions of chest deformation. The methodology presented here produced novel kinematic data that will be useful in developing biofidelic human models. Additional analysis of the data produced by the reported tests as well as additional tests with a variety of loading conditions are required to fully characterize torso response including ribcage fracture tolerance.

  18. Electron-Beam Switches For A High Peak Power Sled-II Pulse Compressor

    SciTech Connect

    Hirshfield, Jay, L.

    2015-12-02

    Omega-P demonstrated triggered electron-beam switches on the L=2 m dual-delay-line X-band pulse compressor at Naval Research Laboratory (NRL). In those experiments, with input pulses of up to 9 MW from the Omega-P/NRL X-band magnicon, output pulses having peak powers of 140-165 MW and durations of 16-20 ns were produced, with record peak power gains M of 18-20. Switch designs are described based on the successful results that should be suitable for use with the existing SLAC SLED-II delay line system, to demonstrate C=9, M=7, and n>>78%, yielding 173ns compressed pulses with peak powers up to 350MW with input of a single 50-MW.

  19. Rocket sled testing of a prototype terrain-relative navigation system

    NASA Technical Reports Server (NTRS)

    Skulsky, Eli David; Johnson, Andrew Edie; Umland, Jeff; Padgett, Curtis; Martin, Bill; Weinstein, Stacy; Wallace, Mark; Steltzner, Adam; Thurman, Sam

    2001-01-01

    The next generation of Martian landers (2007 and beyond) will employ a precision soft-landing capability that will make it possible to explore previously inaccessible regions on the surface of Mars. This capability will be enabled by onboard systems that automatically identify and avoid terrain containing steep slopes or rocks exceeding a particular terrain height. JPL is currently developing such a hazard detection and avoidance system; this system will map the landing zone with a scanning laser radar, identify hazards, select a safe landing zone, and then guide the vehicle to the selected landing area. This paper describes how one component of this system-hazard detection-is being tested using a rocket sled and simulated Martian terrain.

  20. Conditioning causes an increase in Glucose Transporter-4 levels in mononuclear cells in sled dogs

    PubMed Central

    Schnurr, Theresia M.; Reynolds, Arleigh J.; Gustafson, Sally J.; Duffy, Lawrence K.; Dunlap, Kriya L.

    2014-01-01

    This study was designed to investigate the effects of physical conditioning on the expression of the insulin sensitive glucose transporter 4 protein (GLUT4) on mononuclear cells and HOMA-IR levels in dogs and compared to results reported in human skeletal muscle and the skeletal muscle of rodent models. Blood was sampled from conditioned dogs (n=8) and sedentary dogs (n=8). The conditioned dogs were exercised four months prior the experiment and were following a uniform training protocol, whereas the sedentary dogs were not. GLUT4 expression in mononuclear cells and plasma insulin levels were measured using commercially available enzyme-linked immunosorbent assay (ELISA). Blood glucose levels were determined using blood plasma. HOMA-IR was calculated using plasma insulin and blood glucose levels using the linear approximation formula. Our results indicate that the state of conditioning had a significant effect on the GLUT4 expression at the surface of mononuclear cells. HOMA-IR was also affected by conditioning in dogs. GLUT4 levels in mononuclear cells of sled dogs were inversely correlated with the homeostasis model assessment of insulin sensitivity. This study demonstrates that conditioning increases GLUT4 levels in mononuclear cells of sled dogs as it has been previously reported in skeletal muscle. Our results support the potential of white blood cells as a proxy tissue for studying insulin signaling and may lead to development of a minimally invasive and direct marker of insulin resistance. This may be the first report of GLUT4 in mononuclear cells in response to exercise and measured with ELISA. PMID:25236492

  1. The risk of vector-borne infections in sled dogs associated with existing and new endemic areas in Poland: Part 1: A population study on sled dogs during the racing season.

    PubMed

    Bajer, Anna; Mierzejewska, Ewa J; Rodo, Anna; Bednarska, Malgorzata; Kowalec, Maciej; Welc-Falęciak, Renata

    2014-05-28

    The achievements of sled dogs in competitions depend both on their training and on their health. Vector-borne infections may lead to anaemia, affect joints or heart muscle or even cause death. Between December 2009 and October 2010, one hundred and twenty six individual blood samples were collected from 26 sled dog kennels situated in different regions of Poland. The majority of samples were taken during the racing season (winter 2009/10). The prevalences of 3 vector-borne infections- including 2 'old pathogens' Anaplasma phagocytophilum and Babesia canis, and 'new pathogen' Hepatozoon canis-were estimated in sled dogs using PCR and nested PCR. Additionally, 25 serum samples originating from a subset of 3 kennels situated in a tick-borne encephalitis (TBE) endemic area (Mazowiecki region), were tested for antibodies against the tick-borne encephalitis virus (TBEV). Because of the recently reported occurrence of Dirofilaria repens in Central Poland and that of fatal cases of unknown aetiology in two of the kennels, blood samples collected from dogs at these kennels in 2010 and in February-May 2013 and from two unaffected kennels were checked for evidence of presence of this parasite. Babesia canis DNA was detected in 11 sled dogs (4 with clinical babesiosis, 7 asymptomatic; 8.7%) inhabiting mainly endemic regions of Poland (9/11 cases). Three serum samples originating from one location tested positive for TBEV antibodies (total seroprevalence: 3/25=12%, local seroprevalence: 3/12=25%). The risk of TBEV infection was associated with previous B. canis infections. Dirofilaria repens DNA was detected in 15 dogs (44%). Prevalence was especially high in two sled dog kennels situated near Grodzisk Mazowiecki (50-57%). No blood samples tested positive for A. phagocytophilum or H. canis DNA. The present study has established that the prevalence of vector-borne pathogens in working sled dogs is significant in the endemic regions and has justified the important role of

  2. Molecular sled is an eleven-amino acid vehicle facilitating biochemical interactions via sliding components along DNA

    PubMed Central

    Mangel, Walter F.; McGrath, William J.; Xiong, Kan; Graziano, Vito; Blainey, Paul C.

    2016-01-01

    Recently, we showed the adenovirus proteinase interacts productively with its protein substrates in vitro and in vivo in nascent virus particles via one-dimensional diffusion along the viral DNA. The mechanism by which this occurs has heretofore been unknown. We show sliding of these proteins along DNA occurs on a new vehicle in molecular biology, a ‘molecular sled' named pVIc. This 11-amino acid viral peptide binds to DNA independent of sequence. pVIc slides on DNA, exhibiting the fastest one-dimensional diffusion constant, 26±1.8 × 106 (bp)2 s−1. pVIc is a ‘molecular sled,' because it can slide heterologous cargos along DNA, for example, a streptavidin tetramer. Similar peptides, for example, from the C terminus of β-actin or NLSIII of the p53 protein, slide along DNA. Characteristics of the ‘molecular sled' in its milieu (virion, nucleus) have implications for how proteins in the nucleus of cells interact and imply a new form of biochemistry, one-dimensional biochemistry. PMID:26831565

  3. Participation in a 1,000-mile race increases the oxidation of carbohydrate in Alaskan sled dogs.

    PubMed

    Miller, Benjamin F; Drake, Joshua C; Peelor, Frederick F; Biela, Laurie M; Geor, Raymond; Hinchcliff, Kenneth; Davis, Michael; Hamilton, Karyn L

    2015-06-15

    The Alaskan Husky has been specifically bred for endurance performance and is capable of extreme endurance performance. We examined sled dogs in the trained state at the beginning of the race season and after a 1,600-km race (Iditarod). Our hypothesis was that lipids would be the predominant substrate during submaximal exercise in long-distance racing sled dogs, and a 1,600-km race would increase the reliance on lipids during an exercise bout at the same absolute exercise intensity. The experiments were completed over three testing periods, which were completed in January of two different years before participation in a 1,600-km race, or in March shortly after completion of a 1,600-km race. After determination of H(13)CO3 (-) recovery, the dogs were tested with primed continuous infusions of [1,1,2,3,3-(2)H]glycerol, [3-(13)C]lactate, or [6,6-(2)H2]glucose. During exercise, respiratory exchange ratio was significantly higher in raced (0.92 ± 0.01) compared with nonraced (0.87 ± 0.01) dogs. During exercise, glucose rate of appearance was potentially sustained by a large glycerol rate of disappearance with an increase in lactate rates of oxidation after a 1,600-km race. Therefore, contrary to our hypothesis, the sled dogs were dependent on carbohydrate energy sources, a reliance that increased further after participation in a 1,600-km race.

  4. Occupant kinematics in low-speed frontal sled tests: Human volunteers, Hybrid III ATD, and PMHS.

    PubMed

    Beeman, Stephanie M; Kemper, Andrew R; Madigan, Michael L; Franck, Christopher T; Loftus, Stephen C

    2012-07-01

    A total of 34 dynamic matched frontal sled tests were performed, 17 low (2.5g, Δv=4.8kph) and 17 medium (5.0g, Δv=9.7kph), with five male human volunteers of approximately 50th percentile height and weight, a Hybrid III 50th percentile male ATD, and three male PMHS. Each volunteer was exposed to two impulses at each severity, one relaxed and one braced prior to the impulse. A total of four tests were performed at each severity with the ATD and one trial was performed at each severity with each PMHS. A Vicon motion analysis system, 12 MX-T20 2 megapixel cameras, was used to quantify subject 3D kinematics (±1mm) (1kHz). Excursions of select anatomical regions were normalized to their respective initial positions and compared by test condition and between subject types. The forward excursions of the select anatomical regions generally increased with increasing severity. The forward excursions of relaxed human volunteers were significantly larger than those of the ATD for nearly every region at both severities. The forward excursions of the upper body regions of the braced volunteers were generally significantly smaller than those of the ATD at both severities. Forward excursions of the relaxed human volunteers and PMHSs were fairly similar except the head CG response at both severities and the right knee and C7 at the medium severity. The forward excursions of the upper body of the PMHS were generally significantly larger than those of the braced volunteers at both severities. Forward excursions of the PMHSs exceeded those of the ATD for all regions at both severities with significant differences within the upper body regions. Overall human volunteers, ATD, and PMHSs do not have identical biomechanical responses in low-speed frontal sled tests but all contribute valuable data that can be used to refine and validate computational models and ATDs used to assess injury risk in automotive collisions.

  5. A Sled-Mounted Vibroseis Seismic Source for Geological Studies in Antarctica

    NASA Astrophysics Data System (ADS)

    Speece, M. A.; Luyendyk, B. P.; Harwood, D. M.; Powell, R. D.; Wilson, D. S.; Pekar, S. F.; Tulaczyk, S. M.; Rack, F. R.

    2013-12-01

    Given the success of recent vibrator seismic source (vibroseis) tests in Antarctica, we propose the purchase of a large vibroseis for dedicated use by United States Antarctic Program (USAP) projects in Antarctica. Long seismic reflection profiles across Antarctica can be accomplished efficiently by pulling a sled-mounted vibrator that in turn pulls a snow streamer of gimbaled geophones. A baseplate or pad in the center of the sled will be lowered to the ground and support most of the weight of the vibrator assembly while an actuator vibrates the ground at each source location. The vibroseis will be moved to remote locations using over-ice/snow traverses given the increased reliance on traversing for supplying remote sites in Antarctica. Total vibrator hold-down weight when fully assembled will be ~66,000 lbs. Other design features include a 475 HP Caterpillar C15 diesel engine for the hydraulic power unit. The new vibrator will use an INOVA P-wave vibrator system: new Model PLS-362 actuator with up to 60,000 lbs of peak force and frequency limit of 5 Hz to 250Hz. Antarctic research objectives that could be impacted by the use of a vibrator include: (1) mapping of sub-ice stratigraphic sequences for drilling for paleoclimate information, e.g. the deep sedimentary basins of West Antarctica (Ross and Ronne-Filchner Ice Shelves and related divides); (2) correlating offshore and onshore seismic data and complementing airborne geophysical surveys to help determine Antarctica's geologic history; (3) identifying ice-bedrock interface properties and exploring grounding-line processes for ice dynamics; (4) exploring subglacial lakes and water-routing systems; and, (5) investigating the physical properties of ice sheets. An Antarctic Vibroseis Advisory Committee (AVAC) will promote the use of the vibroseis capability among Antarctic geophysical, geological, glaciological and related scientists and groups by encouraging and facilitating the development and submission of

  6. The longitudinal effects of resisted sprint training using weighted sleds vs. weighted vests.

    PubMed

    Clark, Kenneth P; Stearne, David J; Walts, Cory T; Miller, Anthony D

    2010-12-01

    The purpose of this study was to determine the longitudinal effects of weighted sled (WS) and weighted vest (WV) sprint training on maximum velocity sprint performance and kinematics. Twenty male collegiate lacrosse players were randomly assigned to a WS group (n = 7) towing 10% body mass, a WV group (n = 6) loaded with 18.5% body mass, or an unresisted (UR) active control group (n = 7). All subjects completed 13 training sessions over 7 weeks. Pre- and post-test measures of sprint time and average velocity across the distance interval of 18.3 to 54.9 m were used to assess sprint performance, whereas high-speed video (300 Hz) and motion-analysis software were used to analyze stride length, stride rate, ground contact time, and flight time. A 3 × 2 repeated measures analysis of variance was performed for each dependent variable and revealed no significant between-group differences for any of the sprint performance or kinematic stride cycle measures. Effect size statistics suggested small improvements in 18.3- to 54.9-m sprint time and average velocity for the UR group but only trivial improvements for the WS and WV groups. With regard to sprint performance, the results indicate that WS and WV training had no beneficial effect compared with UR training. In fact, for the loads used by WS and WV in this study, UR training may actually be superior for improving sprint performance in the 18.3- to 54.9-m interval.

  7. Misuse study of latch attachment: a series of frontal sled tests.

    PubMed

    Menon, Rajiv; Ghati, Yoganand

    2007-01-01

    This study was initiated to quantify the effects of the misuse in LATCH lower webbing. In the short period since the implementation of the LATCH system several cases of potential misuses have been reported. A series of sled tests in frontal impact mode were conducted with various misuse conditions (loose attachment of LATCH lower webbing, misrouting of LATCH lower webbing and child seat back inclination) for both forward and rearward facing child safety seats (FFCSS and RFCSS). Results from these tests are compared and discussed with that of the standard test with no misuse and showed that as the slack in the lower LATCH webbing increased, ATD injury measures exceeded the limits. The FFCSS tests in the reclined condition yielded lower injury values for all except the chest G's when compared to the standard upright test. In the misrouting tests the ATD kinematics depended on the routing pivot point, the lower the pivot point the better the ATD kinematics. Similar findings were also observed in the RFCSS tests. The use of top tether with the FFCSS substantially improved the performance of the Hybrid III 3 year old ATD in spite of misuse conditions and the injury values were lower than the corresponding tests with no top tether. The effective reduction was 37% in the HIC values, 6% in the chest G's, 30% in the head excursion, 22 % in the knee excursion and finally 37 % reduction in the Nij values.

  8. Comparison of Hybrid III, Thor-alpha and PMHS Response in Frontal Sled Tests.

    PubMed

    Vezin, Philippe; Bruyere-Garnier, Karine; Bermond, François; Verriest, Jean Pierre

    2002-11-01

    Two series of nine frontal sled tests were conducted to evaluate the behavior of the Hybrid III and Thor-alpha dummies. The first series was conducted at 50 kph with airbag and 4 kN force-limited shoulder belt and the second series at 30 kph and only a 4 kN force-limited shoulder belt. In each series, three replicate tests were conducted with each dummy and compared with three PMHS. The data provided by the same instrumentation located at the same position were compared to assess the biofidelity of both dummies. The results were mass scaled in order to account for the differences between the anthropometry of the cadaver. The good test-to-test repeatability for each dummy permitted to compare the mean value of each recorded parameter. Based on the cadaver response, the results show that the Thor-alpha provides responses that are more similar to those of PMHS than the Hybrid III. The flexible joints in the thoracic spine, the sternum design and the more humanlike ribcage give more similar accelerations than the Hybrid III as compared to those of the PMHS. Nevertheless, some parts have to be improved in order to better follow the behavior of the human subject. The head-neck complex, the chest, the shoulder and the pelvis of the Thor-alpha have a more humanlike behavior but some differences remain. The distribution of the deceleration between the components is sometimes different compared to those of the cadaver, even if the resultants are similar. The dummies and most particularly the Hybrid III are less sensitive to the change in restraint systems and tests conditions than a cadaver.

  9. The effect of acute exercise on GLUT4 levels in peripheral blood mononuclear cells of sled dogs.

    PubMed

    Schnurr, Theresia M; Reynolds, Arleigh J; Komac, Alyssa M; Duffy, Lawrence K; Dunlap, Kriya L

    2015-07-01

    Using sled dogs as exercise model, our objectives of this study were to 1) assess the effects of one acute bout of high-intensity exercise on surface GLUT4 concentrations on easily accessible peripheral blood mononuclear cells (PBMC) and 2) compare our findings with published research on exercise induced GLUT4 in skeletal muscle. During the exercise bout, dogs ran 5 miles at approximately 90% of VO2 max. PMBC were collected before exercise (baseline), immediately after exercise and after 24h recovery.GLUT4 was measured via ELISA. Acute exercise resulted in a significant increase on surface GLUT4 content on PBMC. GLUT4 was increased significantly immediately after exercise (~ 50%; p<0.05) and reduced slightly by 24h post-exercise as compared to baseline (~ 22%; p>0.05). An effect of acute exercise on GLUT4 levels translocated to the cell membrane was observed, with GLUT4 levels not yet returned to baseline after 24h post-exercise. In conclusion, the present investigation demonstrated that acute high-intensity exercise increased GLUT4 content at the surface of PBMC of sled dogs as it has been reported in skeletal muscle in other species. Our findings underline the potential use of peripheral blood mononuclear cell GLUT4 protein content as minimally invasive proxy to investigate relationships between insulin sensitivity, insulin resistance, GLUT4 expression and glucose metabolism.

  10. The conduction system in sudden death in Alaskan sled dogs during the Iditarod race and/or during training.

    PubMed

    Bharati, S; Cantor, G H; Leach, J B; Schmidt, K E; Blake, J

    1997-03-01

    Using serial section examination, we studied the conduction system in five Alaskan sled dogs that died suddenly; four during the Iditarod race and one during training. We compared our findings with the conduction system of three sled dogs of similar age that died of natural causes unrelated to the cardiovascular system. The conduction system of sudden death dogs revealed marked fibrosis of the sinoatrial (SA) node and/or its approaches and narrowing of the SA nodal artery in 3 dogs, fibrosis and marked fatty infiltration in and around the AV node in all 5, total isolation and/or tenuous connection of the AV node with its approaches in 4, fat and fibrosis in the AV bundle and bundle branches to a varying degree in all, and focal fibrotic scars in the left ventricle with fat and/or some disarray in 3. The control group revealed mild fibro-fatty changes in the conduction system without fibrotic scar areas in the heart. These findings are similar to the pathological findings in and around the conduction system in cases of sudden death in humans, especially trained athletes. These changes may form an anatomical substrate for an arrhythmic event in susceptible dogs during an altered physiological state.

  11. Dynamic properties of the upper thoracic spine-pectoral girdle (UTS-PG) system and corresponding kinematics in PMHS sled tests.

    PubMed

    Stammen, Jason A; Herriott, Rodney; Kang, Yun-Seok; Dupaix, Rebecca; Bolte, John

    2012-10-01

    Anthropomorphic test devices (ATDs) should accurately depict head kinematics in crash tests, and thoracic spine properties have been demonstrated to affect those kinematics. To investigate the relationships between thoracic spine system dynamics and upper thoracic kinematics in crash-level scenarios, three adult post-mortem human subjects (PMHS) were tested in both Isolated Segment Manipulation (ISM) and sled configurations. In frontal sled tests, the T6-T8 vertebrae of the PMHS were coupled through a novel fixation technique to a rigid seat to directly measure thoracic spine loading. Mid-thoracic spine and belt loads along with head, spine, and pectoral girdle (PG) displacements were measured in 12 sled tests conducted with the three PMHS (3-pt lap-shoulder belted/unbelted at velocities from 3.8 - 7.0 m/s applied directly through T6-T8). The sled pulse, ISM- derived characteristic properties of that PMHS, and externally applied forces due to head-neck inertia and shoulder belt constraint were used to predict kinematic time histories of the T1-T6 spine segment. The experimental impulse applied to the upper thorax was normalized to be consistent with a T6 force/sled acceleration sinusoidal profile, and the result was an improvement in the prediction of T3 X-axis displacements with ISM properties. Differences between experimental and model-predicted displacement-time history increases were quantified with respect to speed. These discrepancies were attributed to the lack of rotational inertia of the head-neck late in the event as well as restricted kyphosis and viscoelasticity of spine constitutive structures through costovertebral interactions and mid-spine fixation. The results indicate that system dynamic properties from sub-injurious ISM testing could be useful for characterizing forward trajectories of the upper thoracic spine in higher energy crash simulations, leading to improved biofidelity for both ATDs and finite element models.

  12. Breed-specific ancestry studies and genome-wide association analysis highlight an association between the MYH9 gene and heat tolerance in Alaskan sprint racing sled dogs.

    PubMed

    Huson, Heather J; vonHoldt, Bridgett M; Rimbault, Maud; Byers, Alexandra M; Runstadler, Jonathan A; Parker, Heidi G; Ostrander, Elaine A

    2012-02-01

    Alaskan sled dogs are a genetically distinct population shaped by generations of selective interbreeding with purebred dogs to create a group of high-performance athletes. As a result of selective breeding strategies, sled dogs present a unique opportunity to employ admixture-mapping techniques to investigate how breed composition and trait selection impact genomic structure. We used admixture mapping to investigate genetic ancestry across the genomes of two classes of sled dogs, sprint and long-distance racers, and combined that with genome-wide association studies (GWAS) to identify regions that correlate with performance-enhancing traits. The sled dog genome is enhanced by differential contributions from four non-admixed breeds (Alaskan Malamute, Siberian Husky, German Shorthaired Pointer, and Borzoi). A principal components analysis (PCA) of 115,000 genome-wide SNPs clearly resolved the sprint and distance populations as distinct genetic groups, with longer blocks of linkage disequilibrium (LD) observed in the distance versus sprint dogs (7.5-10 and 2.5-3.75 kb, respectively). Furthermore, we identified eight regions with the genomic signal from either a selective sweep or an association analysis, corroborated by an excess of ancestry when comparing sprint and distance dogs. A comparison of elite and poor-performing sled dogs identified a single region significantly associated with heat tolerance. Within the region we identified seven SNPs within the myosin heavy chain 9 gene (MYH9) that were significantly associated with heat tolerance in sprint dogs, two of which correspond to conserved promoter and enhancer regions in the human ortholog.

  13. The risk of vector-borne infections in sled dogs associated with existing and new endemic areas in Poland. Part 2: Occurrence and control of babesiosis in a sled dog kennel during a 13-year-long period.

    PubMed

    Bajer, Anna; Mierzejewska, Ewa J; Rodo, Anna; Welc-Falęciak, Renata

    2014-05-28

    The achievements of sled dogs in competitions depend both on their training and on their health. Vector-borne infections may lead to anemia, affect joints or heart muscles or even cause death. Canine babesiosis is an emerging, quickly spreading tick-borne disease in Central Europe. Over a 13-year period (2000-2012) the occurrence of babesiosis cases was analyzed in one sled dog kennel situated in Kury, a village near Tłuszcz (N 52°24'56.78″, E 21°30'37.55″) in Central Poland. Twenty cases/episodes of babesiosis were noted among the 10-12 dogs living in the kennel. In 2000-2004, no cases of babesiosis were noted; the first two cases were noted in April 2005. Since that time, only one dog remained uninfected; 6 dogs were infected once, 3 dogs demonstrated symptoms of babesiosis twice, one dog was infected three times and one dog had it five times. Babesiosis appeared in Spring and Autumn, despite the application of anti-tick treatment. No fatal cases were recorded, but in one case a splenectomy was performed due to splenomegaly and spleen rupture. Additionally, the abundance of the main Babesia canis vector, the Dermacentor reticulatus tick, was estimated and monitored during a 4-year period (2008-2012) close to the dog kennel. The abundance of questing ticks was high in 2008 and 2009, but dropped by 10-fold between 2010 and 2012, when the abandoned meadow was cut and used as horse pasture by the local farmer. The regular occurrence, typical seasonal pattern and identification of B. canis DNA in questing tick from this locality confirmed the establishment of a new hyper enzootic region for canine babesiosis. The effectiveness and schedule of applied preventive measures were discussed.

  14. Whole-body kinematic and dynamic response of restrained PMHS in frontal sled tests.

    PubMed

    Forman, Jason; Lessley, David; Kent, Richard; Bostrom, Ola; Pipkorn, Bengt

    2006-11-01

    The literature contains a wide range of response data describing the biomechanics of isolated body regions. Current data for the validation of frontal anthropomorphic test devices and human body computational models lack, however, a detailed description of the whole-body response to loading with contemporary restraints in automobile crashes. This study presents data from 14 frontal sled tests describing the physical response of postmortem human surrogates (PMHS) in the following frontal crash environments: A) (5 tests) driver position, force-limited 3-point belt plus airbag restraint (FLB+AB), 48 km/h deltaV. B) (3 tests) passenger position, FLB+AB restraint, 48 km/h deltaV. C) (3 tests) passenger position, standard (not force-limited) 3-point belt plus air bag restraint (SB+AB), 48 km/h deltaV. D) (3 tests) passenger position, standard 3-point belt restraint (SB), 29 km/h deltaV. Reported data include x-axis and z-axis (SAE occupant reference frame) accelerations of the head, spine (upper, middle, and lower), and pelvis; rate of angular rotation of the head about y-axis; displacements of the head, upper spine, pelvis and knee relative to the vehicle buck; and deformation contours of the upper and lower chest. A variety of kinematic trends are identified across the different test conditions, including a decrease in head and thorax excursion and a change in the nature of the excursion in the driver position compared to the passenger position. Despite this increase in forward excursion when compared to the driver's side FLB+AB tests, the passenger's side FLB+AB tests resulted in greater peak thoracic (T8) x-axis accelerations (passenger's side -29 g; driver's side -22 g;) and comparable maximum chest deflection (passenger's side - 23+/-3.1% of the undeformed chest depth; driver's side - 23+/-5.6%; ). In the 48 km/h passenger's side tests, the head excursion associated with the force-limiting belt system was approximately 15% greater than that for a standard belt

  15. Kinematics and dynamics of the pelvis in the process of submarining using PMHS sled tests.

    PubMed

    Luet, Carole; Trosseille, Xavier; Drazétic, Pascal; Potier, Pascal; Vallancien, Guy

    2012-10-01

    This study focused on a better understanding and characterization of the submarining phenomenon that occurs in frontal crashes when the lap belt slides over the anterior superi or iliac spine. Submarining is the consequence of the pelvis kinematics relative to the lap belt, driven by the equilibrium of forces and moments applied to the pelvis. The study had two primary purposes; the first was to provide new PMHS data in submarining test configurations, the second was to investigate the Hybrid II and Hybrid III dummies biofidelity regarding submarining. Several Post Mortem Human Subject (PMHS) studies have been published on this subject. However, the lack of information about the occupant initial positioning and the use of car seats make it difficult to reconstruct these tests. Furthermore, the two dummies are rarely compared to PMHS in submarining test configurations. A fifteen frontal sled test campaign was carried out on two Anthropomorphic Test Devices (ATDs) and nine PMHS. The test environment was designed to be reproducible. It consisted of a rigid seat, a 2-poi nts shoulder belt and a 2-points lap belt instrumented to record their 3D forces at anchorage. The subjects were instrumented with angular sensors at the sacrum, T1 and T12 levels to record their initial angles. Kinematics was measured at these three levels by means of three accelerometers and angular velocity sensors. A PMHS positioning procedure was developed to ensure repeatability. A pre-test was performed on each subject to characterize its lumbar spine static behavior. All the subjects were CT-scanned from head to toe prior to the test. The campaign was divided into three test configurations leading to different surrogates' interaction with the environment and different kinematics. This resulted in a wider range of behaviors for the dummies evaluation. The deceleration pulse, initial lap belt angle, lap belt slack, seat pan angle and footrest position varied. The Hybrid II and Hybrid III dummies

  16. Frontal sled tests comparing rear and forward facing child restraints with 1-3 year old dummies.

    PubMed

    Sherwood, C P; Crandall, J R

    2007-01-01

    Although most countries recommend transitioning children from rear facing (RF) to forward facing (FF) child restraints at one year of age, Swedish data suggests that RF restraints are more effective. The objective of this study was to compare RF and FF orientations in frontal sled tests. Four dummies (CRABI 12 mo, Q1.5, Hybrid III 3 yr, and Q3) were used to represent children from 1 to 3 years of age. Restraint systems tested included both 1) LATCH and 2) rigid ISOFIX with support leg designs. Rear facing restraints with support legs provided the best results for all injury measures, while RF restraints in general provided the lowest chest displacements and neck loads.

  17. Influence of sustained low-efficiency diafiltration (SLED-f) on interstitial fluid concentrations of fluconazole in a critically ill patient: Use of microdialysis.

    PubMed

    Sinnollareddy, Mahipal G; Roberts, Michael S; Lipman, Jeffrey; Peake, Sandra L; Roberts, Jason A

    2015-07-01

    Acute kidney injury is a common complication in critically ill patients, and hybrid techniques including sustained low-efficiency dialysis/diafiltration (SLED-f) are being increasingly utilised in intensive care units. Most fungal infections occur in the interstitial fluid (ISF) of tissues and successful treatment of a fungal infection relies on the ability of an antifungal agent to achieve adequate concentrations at the site of infection. Tissue distribution of antimicrobials is impaired in critically ill patients owing to a variety of disease-related physiological changes, e.g. sepsis. Fluconazole is a widely used antifungal agent used to treat Candida spp. infections in critically ill patients. The implications for ISF concentrations of enhanced elimination during renal replacement therapy have not yet been reported for fluconazole. The aim of this single-patient case report was to describe the influence of SLED-f on subcutaneous (SC) ISF concentrations of fluconazole and the implications for achieving pharmacokinetic/pharmacodynamic targets. Serial blood and ISF samples were collected at pre- and post-filter ports within the SLED-f circuit and subcutaneously inserted microdialysis probe, respectively. Fluconazole concentrations were measured using a validated chromatography method. The SC ISF-to-plasma partition coefficient of fluconazole in this patient was 0.91, indicating rapid equilibrium. SC ISF fluconazole concentrations consistently decreased after initiating SLED-f. The majority of the fluconazole was eliminated from the SC ISF as a result of redistribution. Considering the extensive tissue re-distribution of fluconazole and observed elimination from tissue compartments, higher doses may be required to treat deep-seated fungal infections.

  18. Responses of the Q6/Q6s ATD Positioned in Booster Seats in the Far-Side Seat Location of Side Impact Passenger Car and Sled Tests.

    PubMed

    Tylko, Suzanne; Bohman, Katarina; Bussières, Alain

    2015-11-01

    Passenger car side impact crash tests and sled tests were conducted to investigate the influence of booster seats, near-side occupant characteristics and vehicle interiors on the responses of the Q6/Q6s child ATD positioned in the rear, far-side seating location. Data from nine side impact sled tests simulating a EuroNCAP AEMD barrier test were analyzed with data obtained from 44 side impact crash tests. The crash tests included: FMVSS 214 and IIHS MDB, moving car-to-stationary car and moving car-to-moving car. A Q6 or prototype Q6s ATD was seated on the far-side, using a variety of low and high back booster seats. Head and chest responses were recorded and ATD motions were tracked with high-speed videos. The vehicle lateral accelerations resulting from MDB tests were characterized by a much earlier and more rapid rise to peak than in tests where the bullet was another car. The near-side seating position was occupied by a Hybrid III 10-year-old ATD in the sled tests, and a rear or front facing child restraint or a 5th percentile side impact ATD in the crash tests. Head impacts occurred more frequently in vehicles where a forward facing child restraint was present behind the driver seat for both the low and high back booster seats. Pretensioners were found to reduce lateral head displacements in all sled test configurations but the greatest reduction in lateral excursion was obtained with a high back booster seat secured with LATCH and tested in combination with pretensioners.

  19. Molecular sled is an eleven-amino acid vehicle facilitating biochemical interactions via sliding components along DNA

    DOE PAGES

    Mangel, Walter F.; McGrath, William J.; Xiong, Kan; ...

    2016-02-02

    Recently, we showed the adenovirus proteinase interacts productively with its protein substrates in vitro and in vivo in nascent virus particles via one-dimensional diffusion along the viral DNA. The mechanism by which this occurs has heretofore been unknown. We show sliding of these proteins along DNA occurs on a new vehicle in molecular biology, a ‘molecular sled’ named pVIc. This 11-amino acid viral peptide binds to DNA independent of sequence. pVIc slides on DNA, exhibiting the fastest one-dimensional diffusion constant, 26±1.8 × 106 (bp)2 s−1. pVIc is a ‘molecular sled,’ because it can slide heterologous cargos along DNA, for example, amore » streptavidin tetramer. Similar peptides, for example, from the C terminus of β-actin or NLSIII of the p53 protein, slide along DNA. Finally, characteristics of the ‘molecular sled’ in its milieu (virion, nucleus) have implications for how proteins in the nucleus of cells interact and imply a new form of biochemistry, one-dimensional biochemistry.« less

  20. A comparison between a child-size PMHS and the Hybrid III 6 YO in a sled frontal impact.

    PubMed

    Lopez-Valdes, Francisco J; Forman, Jason; Kent, Richard; Bostrom, Ola; Segui-Gomez, Maria

    2009-10-01

    As pediatric PMHS data are extremely limited, evidence of kinematic differences between pediatric ATDs and live humans comes from comparison of laboratory data to field crash data. Despite the existence of regulations intended to prevent head injuries, these remain the most common serious injuries sustained by children in crashes. In this study, nine frontal sled tests using a Hybrid III 6YO and three tests performed with a child-size adult PMHS were compared, with focus on the kinematic responses (especially of the head) and the seatbelt forces generated during the impact. Two different restraint systems (a pretensioning, force-limiting seatbelt, and a non pretensioning force-limiting standard belt) and two different impact speeds (29 km/h and 48 km/h) were compared. Data from the PMHS were scaled using the erect sitting height of a 50th percentile 6YO and both scaled and unscaled data are presented. The ATD predicted correctly the peak values of the scaled displacements of the PMHS, but differences in relevant parameters such as torso angle and resultant acceleration at different locations were found between the dummy and the PMHS. The ATD's stiffer thoracic spine is hypothesized as a major cause of these differences.

  1. A comparison between a child-size PMHS and the Hybrid III 6 YO in a sled frontal impact

    PubMed Central

    Lopez-Valdes, Francisco J.; Forman, Jason; Kent, Richard; Bostrom, Ola; Segui-Gomez, Maria

    2009-01-01

    As pediatric PMHS data are extremely limited, evidence of kinematic differences between pediatric ATDs and live humans comes from comparison of laboratory data to field crash data. Despite the existence of regulations intended to prevent head injuries, these remain the most common serious injuries sustained by children in crashes. In this study, nine frontal sled tests using a Hybrid III 6YO and three tests performed with a child-size adult PMHS were compared, with focus on the kinematic responses (especially of the head) and the seatbelt forces generated during the impact. Two different restraint systems (a pretensioning, force-limiting seatbelt, and a non pretensioning force-limiting standard belt) and two different impact speeds (29 km/h and 48 km/h) were compared. Data from the PMHS were scaled using the erect sitting height of a 50th percentile 6YO and both scaled and unscaled data are presented. The ATD predicted correctly the peak values of the scaled displacements of the PMHS, but differences in relevant parameters such as torso angle and resultant acceleration at different locations were found between the dummy and the PMHS. The ATD’s stiffer thoracic spine is hypothesized as a major cause of these differences. PMID:20184847

  2. Molecular sled is an eleven-amino acid vehicle facilitating biochemical interactions via sliding components along DNA

    SciTech Connect

    Mangel, Walter F.; McGrath, William J.; Xiong, Kan; Graziano, Vito; Blainey, Paul C.

    2016-02-02

    Recently, we showed the adenovirus proteinase interacts productively with its protein substrates in vitro and in vivo in nascent virus particles via one-dimensional diffusion along the viral DNA. The mechanism by which this occurs has heretofore been unknown. We show sliding of these proteins along DNA occurs on a new vehicle in molecular biology, a ‘molecular sled’ named pVIc. This 11-amino acid viral peptide binds to DNA independent of sequence. pVIc slides on DNA, exhibiting the fastest one-dimensional diffusion constant, 26±1.8 × 106 (bp)2 s−1. pVIc is a ‘molecular sled,’ because it can slide heterologous cargos along DNA, for example, a streptavidin tetramer. Similar peptides, for example, from the C terminus of β-actin or NLSIII of the p53 protein, slide along DNA. Finally, characteristics of the ‘molecular sled’ in its milieu (virion, nucleus) have implications for how proteins in the nucleus of cells interact and imply a new form of biochemistry, one-dimensional biochemistry.

  3. Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase.

    PubMed

    Martínez-Valencia, María Asunción; Romero-Arenas, Salvador; Elvira, José L L; González-Ravé, José María; Navarro-Valdivielso, Fernando; Alcaraz, Pedro E

    2015-06-27

    Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm)) on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg) performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak), a peak rate of force development (RFDpeak) and time to RFD (TRFD) in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s-1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s-1, p ≤ 0.01). Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

  4. Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase

    PubMed Central

    Martínez-Valencia, María Asunción; Romero-Arenas, Salvador; Elvira, José L.L.; González-Ravé, José María; Navarro-Valdivielso, Fernando; Alcaraz, Pedro E.

    2015-01-01

    Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm)) on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg) performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak), a peak rate of force development (RFDpeak) and time to RFD (TRFD) in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s−1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s−1, p ≤ 0.01). Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration. PMID:26240657

  5. Comparison of AIS 1990 update 98 versus AIS 2005 for describing PMHS injuries in lateral and oblique sled tests.

    PubMed

    Yoganandan, Narayan; Pintar, Frank A; Humm, John R; Stadter, Gregory W; Curry, William H; Brasel, Karen J

    2013-01-01

    This study analyzed skeletal and organ injuries in pure lateral and oblique impacts from 20 intact post mortem human surrogate (PMHS) sled tests at 6.7 m/s. Injuries to the shoulder, thorax, abdomen, pelvis and spine were scored using AIS 1990-1998 update and 2005. The Injury Severity Scores (ISS) were extracted for both loadings from both versions. Mean age, stature, total body mass and body mass index for pure lateral and oblique tests: 58 and 55 years, 1.7 and 1.8 m, 69 and 66 kg, and 24 and 21 kg/m(2). Skeletal injuries (ribs, sternum) occurred in both impacts. However, oblique impacts resulted in more injuries. Pure lateral and oblique impacts ISS: 0 to 16 and 0 to 24, representing a greater potential for injury-related consequences in real-world situations in oblique impacts. Internal organs were more involved in oblique impacts. ISS decreased in AIS 2005, reflecting changes to scoring and drawing attention to potential effects for pre-hospital care/medical aspects. Mean AIS scores for the two load vectors and two AIS coding schemes are included. From automotive crashworthiness perspectives, decreases in injury severities might alter injury risk functions with a shift to lower metrics for the same risk level than current risk estimations. This finding influences dummy-based injury criteria and occupant safety as risk functions are used for countermeasure effectiveness and cost-benefit analyses by regulatory bodies. Increase in organ injuries in oblique loading indicate the importance of this vector as current dummies and injury criteria used in regulations are based on pure lateral impact data.

  6. Comparison of AIS 1990 update 98 versus AIS 2005 for describing PMHS injuries in lateral and oblique sled tests

    PubMed Central

    Yoganandan, Narayan; Pintar, Frank A.; Humm, John R.; Stadter, Gregory W.; Curry, William H.; Brasel, Karen J.

    2013-01-01

    This study analyzed skeletal and organ injuries in pure lateral and oblique impacts from 20 intact post mortem human surrogate (PMHS) sled tests at 6.7 m/s. Injuries to the shoulder, thorax, abdomen, pelvis and spine were scored using AIS 1990–1998 update and 2005. The Injury Severity Scores (ISS) were extracted for both loadings from both versions. Mean age, stature, total body mass and body mass index for pure lateral and oblique tests: 58 and 55 years, 1.7 and 1.8 m, 69 and 66 kg, and 24 and 21 kg/m2. Skeletal injuries (ribs, sternum) occurred in both impacts. However, oblique impacts resulted in more injuries. Pure lateral and oblique impacts ISS: 0 to 16 and 0 to 24, representing a greater potential for injury-related consequences in real-world situations in oblique impacts. Internal organs were more involved in oblique impacts. ISS decreased in AIS 2005, reflecting changes to scoring and drawing attention to potential effects for pre-hospital care/medical aspects. Mean AIS scores for the two load vectors and two AIS coding schemes are included. From automotive crashworthiness perspectives, decreases in injury severities might alter injury risk functions with a shift to lower metrics for the same risk level than current risk estimations. This finding influences dummy-based injury criteria and occupant safety as risk functions are used for countermeasure effectiveness and cost-benefit analyses by regulatory bodies. Increase in organ injuries in oblique loading indicate the importance of this vector as current dummies and injury criteria used in regulations are based on pure lateral impact data. PMID:24406958

  7. Hematological and metabolic responses to training in racing sled dogs fed diets containing medium, low, or zero carbohydrate.

    PubMed

    Kronfeld, D S; Hammel, E P; Ramberg, C F; Dunlap, H L

    1977-03-01

    In a 28 week study, 18 racing sled dogs were trained to maximal fitness in 12 weeks, sustained through a racing season of 12 weeks, followed by gradual of training of 4 weeks. The dogs were fed a predominantly cereal diet prior to the study; experimental diets containing more chicken and meat by products were introduced from the 2nd to the 4th week of training. On an energy basis, the diets contained protein, fat, and carbohydrate in the proportions of 39:61:0 (diet A), 32:45:23 (diet B), and 28:34:38 (diet C). Blood samples were taken at rest just before the start of training, at 6, 12,24 and 28 weeks; 33 variables were measured on most samples. The results were subjected to analysis of variance. No adverse effects were observed in dogs fed the extreme diet A. Significant relationships to training were shown by serum glutamic oxaloacetic transaminase, creatinine, packed cell volume, calcium, hemoglobin, and globulin. Serum cholesterol concentration increased with the introduction of the higher protein-fat diets; the high concentrations attenuated with time but rose again when training was abated. Dogs on diet A maintained higher serum concentrations of albumin, calcium, magnesium, and free fatty acids during the racing season than did dogs fed diets B or C. They also exhibited the greatest increases in red cell count, hemoglobin concentration, and packed cell volume during training. High values of red cell indices were not sustained through the racing season in dogs fed diet C. In addition to attributes already widely appreciated, viz. a higher energy density an digestibility, the carbohydrate-free, high-fat diet A appeared to confer advantages for prolonged strenuous running in terms of certain metabolic responses to training.

  8. Investigation on occupant ejection in high severity rear impact based on post mortem human subject sled tests.

    PubMed

    Petit, Philippe; Luet, Carole; Potier, Pascal; Vallancien, Guy

    2011-11-01

    Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al. 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection. Extensive literature search has found no full-scale rear impact tests involving Post Mortem Human Subjects (PMHS) conducted in a laboratory environment and resulting in ejection. This paper describes a total of 10 sled tests conducted on 3 belted PMHS using a simplified seat design composed of rigid plates assembled such that the angular and linear stiffness of the seatback (including the foam) was modeled. The initial angular position and the range of motion of the seatback, the size of the PMHS, the slack length of the seatbelt, the angular stiffness of the seatback, and the use of headrest were varied in the test matrix while the pulse was kept constant (triangular acceleration with a peak of 17 G at 30 ms and a duration of 95 ms). In the test series, the tests were not run randomly but the likelihood of occupant ejection was increased systematically until ejection occurred. PMHS seat ejection was observed only for the 95th percentile, initially positioned with a seatback angle relative to the vertical equal to 22°, a range of seatback angular motion equal to 44° and no headrest. Repeating

  9. Rear seat occupant safety: an investigation of a progressive force-limiting, pretensioning 3-point belt system using adult PMHS in frontal sled tests.

    PubMed

    Forman, Jason; Lopez-Valdes, Francisco; Lessley, David; Kindig, Matthew; Kent, Richard; Ridella, Stephen; Bostrom, Ola

    2009-11-01

    Rear seat adult occupant protection is receiving increased attention from the automotive safety community. Recent anthropomorphic test device (ATD) studies have suggested that it may be possible to improve kinematics and reduce injuries to rear seat occupants in frontal collisions by incorporating shoulder-belt force-limiting and pretensioning (FL+PT) technologies into rear seat 3-point belt restraints. This study seeks to further investigate the feasibility and potential kinematic benefits of a FL+PT rear seat, 3-point belt restraint system in a series of 48 kmh frontal impact sled tests (20 g, 80 ms sled acceleration pulse) performed with post mortem human surrogates (PMHS). Three PMHS were tested with a 3-point belt restraint with a progressive (two-stage) force limiting and pretensioing retractor in a sled buck representing the rear seat occupant environment of a 2004 mid-sized sedan. Instrumentation included belt tension load cells, accelerometers on the head and at multiple locations on the spine, and chestbands to measure the chest deformation contours in the transverse plane. The kinematics of the subjects were quantified using off-board, high-speed video. The results of these tests were then compared to matched PMHS tests, published in 2008, performed in the same environment with a standard (not-force limited, not pretensioning) 3-point belt restraint. The FL+PT restraint system resulted in significant (p<0.05) decreases in peak shoulder belt tension (average +/- standard deviation: 4.4 +/- 0.13 kN with the FL+PT belt, 7.8 +/- 0. 6 kN with the standard belt) and 3 ms-resultant, mid-spine acceleration (FL+PT: 34 +/- 3.8 g; standard belt: 44 +/- 1.4 g). The FL+PT tests also produced more forward torso rotation caused by decreased forward excursion of the pelvis and increased payout out of the shoulder belt by the force-limiter. These results support the previous ATD studies that suggest that it may be possible to improve the kinematics of rear seat occupants

  10. Insulin-Like Growth Factor-1 and Selected Insulin-Like Growth Factor Binding Protein Concentrations during an Ultramarathon Sled Dog Race

    PubMed Central

    Brunke, Matthew W.; Frye, Christopher W.; Levine, Corri B.

    2016-01-01

    The objective of this study was to investigate the effects of running a 1000-mile (1600 km) endurance sled dog race on serum insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding proteins 1 and 3 (IGFBP-1 and IGFBP-3). Serum was examined from 12 sled dogs prior to the race, at midrace (approximately 690 km), and again at the finish. IGF-1, IGFBP-1, and IGFBP-3 were assessed using radioimmunoassay or enzyme linked immune-absorbance assays. Mean prerace concentrations were significantly higher than midrace and end-race concentrations at 215.93 ± 80.51 ng/mL, 54.29 ± 25.45 ng/mL, and 55.53 ± 28.25 ng/mL, respectively (P < 0.001). Mean IGFBP-1 concentrations were not different across these time periods at 24.1 ± 15.8 ng/mL, 25.7 ± 14.0 ng/mL, and 26.6 ± 17.6 ng/mL, respectively. IGFBP-3 concentrations showed a modest significant decrease across time periods at 3,067 ± 2,792 ng/mL, 2,626 ± 2,310 ng/mL, and 2,331 ± 2,301 ng/mL, respectively (P < 0.01). Endurance sled dogs show a precipitous drop in serum IGF-1 concentrations. These differences may be related to fuel utilization and excessive negative energy balance associated with the loss of body condition during racing. The relative stability of IGFBP-1 and IGFBP-3 suggests that IGF-1 anabolic signaling is diminished during ultramarathon racing. Further studies comparing the influence of time and duration of exercise versus negative energy balance on serum IGF-1 status are warranted to better understand exercise versus negative energy balance differences. PMID:27689132

  11. Evaluating the effect of ambient particulate pollution on DNA methylation in Alaskan sled dogs: Potential applications for a sentinel model of human health

    PubMed Central

    Montrose, Luke; Noonan, Curtis; Cho, Yoon Hee; Lee, Joongwon; Harley, John; O’Hara, Todd; Cahill, Catherine; Ward, Tony

    2015-01-01

    Background Exposure to ambient particulate matter (PM) is known to be associated with increased morbidity and mortality in human populations. During the winter months in Fairbanks, Alaska, severe temperature inversions lead to elevated concentrations of ambient PM smaller than 2.5 microns (PM2.5). Sled dogs represent an easily accessible environmentally exposed population that may yield findings informative for human health risk assessment. Objectives In this pilot study, we evaluated whether ambient PM was associated with markers of global methylation in sled dogs. Methods Kennels were strategically recruited to provide a wide PM2.5 exposure gradient for the Fairbanks area. Continuous monitoring of ambient PM2.5 was conducted at each kennel during the winter of 2012/13 using a DustTrak 8530. Dogs received a physical examination and assessment of standard hematology and clinical chemistries. Global methylation was determined using the LUminometric Methylation Assay (LUMA) and 5-Methycytosine (5-mC) Quantification. Results Three sled dog kennels (n ~30 dogs/kennel) were evaluated and sampled. The average PM2.5 concentrations measured for kennels A, B, and C were 90 μg/m3, 48 μg/m3, 16 μg/m3 (p< 0.0001), respectively. The average (standard deviation) global methylation percentage for each kennel measured by LUMA was 76.22 (1.85), 76.52 (1.82), and 76.72 (2.26), respectively. The average (standard deviation) global methylation percentage for each kennel measured by 5-mC was 0.16 (0.04), 0.15 (0.04), and 0.15 (0.05), respectively. There was no statistically significant difference between the three kennels and their average global methylation percentage either by LUMA or 5-mC. Conclusions In this study we evaluated global methylation using LUMA and 5-mC and found no differences between kennels, though exposure to ambient PM2.5 was significantly different between kennels. As more information becomes available regarding immunologically-related canine genes and

  12. Responses and Injuries to PMHS in Side-Facing and Oblique Seats in Horizontal Longitudinal Sled Tests per FAA Emergency Landing Conditions.

    PubMed

    Humm, John R; Yoganandan, Narayan; Pintar, Frank A; DeWeese, Richard L; Moorcroft, David M; Taylor, Amanda M; Peterson, Brian

    2016-11-01

    The objective of the present exploratory study is to understand occupant responses in oblique and side-facing seats in the aviation environment, which are increasingly installed in modern aircrafts. Sled tests were conducted using intact Post Mortem Human Surrogates (PMHS) seated in custom seats approximating standard aircraft geometry. End conditions were selected to represent candidate aviation seat and restraint configurations. Three-dimensional head center-of-gravity linear accelerations, head angular velocities, and linear accelerations of the T1, T6, and T12 spinous processes, and sacrum were obtained. Three-dimensional kinematics relative to the seat were obtained from retroreflective targets attached to the head, T1, T6, T12, and sacrum. All specimens sustained spinal injuries, although variations existed by vertebral level. While the tension mechanism was associated with cervical spine injuries, complex distraction-coupled with bending and tension was attributed to thoracolumbar spine injuries. Skeletal fractures to the ribcage were attributed to compression induced by the restraint from the seatbelt, the presence of the armrest, and/or severe motions of the unconstrained torso. Pelvic injuries were also attributed to restraint offered by the lap belt on the accelerating torso-pelvis complex in the absence of the armrest. Lower extremity injuries occurred due to the unconstrained motion (flailing mechanism). These results serve as an initial dataset to understand the kinematics of different body regions, injuries and patterns, and potential injury mechanisms describing PMHS responses in the aviation environment.

  13. Head kinematics in mini-sled tests of foam padding: relevance of linear responses from free motion headform (FMH) testing to head angular responses.

    PubMed

    Ivarsson, J; Viano, D C; Lövsund, P; Parnaik, Y

    2003-08-01

    The revised Federal Motor Vehicle Safety Standard (FMVSS) No. 201 specifies that the safety performance of vehicle upper interiors is determined from the resultant linear acceleration response of a free motion headform (FMH) impacting the interior at 6.7 m/s. This study addresses whether linear output data from the FMH test can be used to select an upper interior padding that decreases the likelihood of rotationally induced brain injuries. Using an experimental setup consisting of a Hybrid III head-neck structure mounted on a mini-sled platform, sagittal plane linear and angular head accelerations were measured in frontal head impacts into foam samples of various stiffness and density with a constant thickness (51 mm) at low (approximately 5.0 m/s), intermediate (approximately 7.0 m/s), and high (approximately 9.6 m/s) impact speeds. Provided that the foam samples did not bottom out, recorded peak values of angular acceleration and change in angular velocity increased approximately linearly with increasing peak resultant linear acceleration and value of the Head Injury Criterion (HIC36). The results indicate that the padding that produces the lowest possible peak angular acceleration and peak change in angular velocity without causing high peak forces is the one that produces the lowest possible HIC36 without bottoming out in the FMH test.

  14. A Comparison of the Hybrid III and BioRID II Dummies in Low-Severity, Rear-Impact Sled Tests.

    PubMed

    Kim, A; Anderson, K F; Berliner, J; Bryzik, C; Hassan, J; Jensen, J; Kendall, M; Mertz, H J; Morrow, T; Rao, A; Wozniak, J A

    2001-11-01

    A BioRID II dummy and a Hybrid III dummy, each representative of a midsize adult male, were tested side-by-side in simulated rear-impact sled tests. In all tests the dummies were restrained by 3-point belt systems. The results of 4 test sets conducted at a nominal change in velocity (deltaV) of 16 km/hr are presented and discussed. In three of the test sets, bucket seats were used. The head restraints were placed in the up-position in two of the three test sets and in the down-position in the third set of tests. In the fourth test set, rigid seats without any head restraints were used. While analyzing the BioRID II data, the presence of an axial neck load acting on the head, which bypassed the upper neck load transducer, was discovered in all the reported tests. The implication of this observation is that the axial force and all the moments measured by the BioRID II upper neck load transducer could be erroneous. A second concern with the BioRID II data was the high frequency noise observed, especially on the T1 acceleration response which is used in the NIC calculation. The 18 Hz filter used to process the T1 acceleration data for the NIC calculation attenuated the peak NIC values by 15% as compared to the SAE 180 filtered values. The unmeasured neck loads and high-frequency noise issues need to be resolved before additional BioRID II testing is done. A third concern with the BioRID II is the initial position of its head in the automotive seating posture. It is higher and more forward than that of the 50(th) percentile adult male.

  15. Pilot evaluation of physical and psychological effects of a physical trek programme including a dog sledding expedition in children and teenagers with cancer

    PubMed Central

    Vallet, Clothilde; André, Nicolas; Gentet, Jean-Claude; Verschuur, Arnauld; Michel, Gérard; Sotteau, Frédéric; Martha, Cécile; Grélot, Laurent

    2015-01-01

    Aim of the study To evaluate the feasibility and to measure the effects of a six-week-long adapted physical activity programme (APAP), including 5 days of intense dog sledding, on the physical and psychological health of children and adolescents treated for cancer. Methods Eleven children and teenagers (4 girls, 7 boys; mean age 14.3 ± 2.9 years) participated in this monocentric pilot programme of adapted physical activities from February 2013 to March 2013. Seven were still on treatment. The programme lasted 6 weeks. A series of physical tests and psychological questionnaires were carried out before and after the programme. Results All children and teenagers completed the full programme. An improvement in all physical and psychological parameters was observed. Statistically significant differences were observed for global self-esteem (6.2 ± 2.1 to 7.7 ± 1.8; p = 0.02), perceived sport competence (5.3 ± 3.2 to 7.4 ± 2; p = 0.02) and perceived physical strength (5.6 ± 2.5 to 7.1 ± 1.8; p = 0.001). Regarding physical tests, the physical training led to statistically significant improvement for sit-ups (13.8 ± 2.6 to 21.75 ± 5.4; p = 0.01), muscle tone (76 ± 23.7 to 100 ± 22.9; p = 0.01), and resting heart rate (96.1 ± 3.2 to 91.6 ± 4.5; p = 0.03). Conclusion This programme is feasible in children and adolescents even during their oncologic treatment. During the 6-week programme, children and adolescents improved their physical and psychological health, and the putative benefits of the APAP are discussed. A larger randomised trial started in 2014. PMID:26284122

  16. An inflatable belt system in the rear seat occupant environment: investigating feasibility and benefit in frontal impact sled tests with a 50th percentile male ATD

    PubMed Central

    Forman, Jason L.; Lopez-Valdes, Francisco J.; Dennis, Nate; Kent, Richard W.; Tanji, Hiromasa; Higuchi, Kazuo

    2010-01-01

    Frontal-impact airbag systems have the potential to provide a benefit to rear seat occupants by distributing restraining forces over the body in a manner not possible using belts alone. This study sought to investigate the effects of incorporating a belt-integrated airbag (“airbelt”) into a rear seat occupant restraint system. Frontal impact sled tests were performed with a Hybrid III 50th percentile male anthropomorphic test device (ATD) seated in the right-rear passenger position of a 2004 mid-sized sedan buck. Tests were performed at 48 km/h (20 g, 100 ms acceleration pulse) and 29 km/h (11 g, 100 ms). The restraints consisted of a 3-point belt system with a cylindrical airbag integrated into the upper portion of the shoulder belt. The airbag was tapered in shape, with a maximum diameter of 16 cm (at the shoulder) that decreased to 4 cm at the mid-chest. A 2.5 kN force-limiter was integrated into the shoulder-belt retractor, and a 2.3 kN pretensioner was present in the out-board anchor of the lap belt. Six ATD tests (three 48 km/h and three 29 km/h) were performed with the airbelt system. These were compared to previous frontal-impact, rear seat ATD tests with a standard (not-force-limited, not-pretensioned) 3-point belt system and a progressive force-limiting (peak 4.4 kN), pretensioning (FL+PT) 3-point belt system. In the 48 km/h tests, the airbelt resulted in significantly less (p<0.05, two-tailed Student’s t-test) posterior displacement of the sternum towards the spine (chest deflection) than both the standard and FL+PT belt systems (airbelt: average 13±1.1 mm standard deviation; standard belt: 33±2.3 mm; FL+PT belt: 23±2.6 mm). This was consistent with a significant reduction in the peak upper shoulder belt force (airbelt: 2.7±0.1 kN; standard belt: 8.7±0.3 kN; FL+PT belt: 4.4±0.1 kN), and was accompanied by a small increase in forward motion of the head (airbelt: 54±0.4 cm; standard belt: 45±1.3 cm; FL+PT belt: 47±1.1 cm) The airbelt system

  17. Portable Linear Sled (PLS) for biomedical research

    NASA Technical Reports Server (NTRS)

    Vallotton, Will; Matsuhiro, Dennis; Wynn, Tom; Temple, John

    1993-01-01

    The PLS is a portable linear motion generating device conceived by researchers at Ames Research Center's Vestibular Research Facility and designed by engineers at Ames for the study of motion sickness in space. It is an extremely smooth apparatus, powered by linear motors and suspended on air bearings which ride on precision ground ceramic ways.

  18. Low-Temperature Flex Durability of Fabrics for Polar Sleds

    DTIC Science & Technology

    2014-10-06

    HMW-PE sheets. The pontoons consist of cylindrical woven-fabric shells enclosing impermeable inner liners ...an impermeable inner liner (clear) as shown with this short sample...materials designated Samples 14 and 16 here (Weale et al. 2011). The photo on the right in Figure 4 shows the liner -shell construction of this pontoon

  19. SLED: Semantic Label Embedding Dictionary Representation for Multilabel Image Annotation.

    PubMed

    Cao, Xiaochun; Zhang, Hua; Guo, Xiaojie; Liu, Si; Meng, Dan

    2015-09-01

    Most existing methods on weakly supervised image annotation rely on jointly unsupervised feature representation, the components of which are not directly correlated with specific labels. In practical cases, however, there is a big gap between the training and the testing data, say the label combination of the testing data is not always consistent with that of the training. To bridge the gap, this paper presents a semantic label embedding dictionary representation that not only achieves the discriminative feature representation for each label in the image, but also mines the semantic relevance between co-occurrence labels for context information. More specifically, to enhance the discriminative representation of labels, the training data is first divided into a set of overlapped groups by graph shift based on the exclusive label graph. Afterward, given a group of exclusive labels, we try to learn multiple label-specific dictionaries to explicitly decorrelate the feature representation of each label. A joint optimization approach is proposed according to the Fisher discrimination criterion for seeking its solution. Then, to discover the context information hidden in the co-occurrence labels, we explore the semantic relationship between visual words in dictionaries and labels in a multitask learning way with respect to the reconstruction coefficients of the training data. In the annotation stage, with the discriminative dictionaries and exclusive label groups as well as a group sparsity constraint, the reconstruction coefficients of a test image can be easily obtained. Finally, we introduce a label propagation scheme to compute the score of each label for the test image based on its reconstruction coefficients. Experimental results on three challenging data sets demonstrate that our proposed method leads to significant performance gains over existing methods.

  20. Tradition and Technology: Sea Ice Science on Inuit Sleds

    NASA Astrophysics Data System (ADS)

    Wilkinson, Jeremy P.; Hanson, Susanne; Hughes, Nick E.; James, Alistair; Jones, Bryn; MacKinnon, Rory; Rysgaard, Søren; Toudal, Leif

    2011-01-01

    The Arctic is home to a circumpolar community of native people whose culture and traditions have enabled them to thrive in what most would perceive as a totally inhospitable and untenable environment. In many ways, sea ice can be viewed as the glue that binds these northern communities together; it is utilized in all aspects of their daily life. Sea ice acts as highways of the north; indeed, one can travel on these highways with dogsleds and snowmobiles. These travels over the frozen ocean occur at all periods of the sea ice cycle and over different ice types and ages. Excursions may be hunting trips to remote regions or social visits to nearby villages. Furthermore, hunting on the sea ice contributes to the health, culture, and commercial income of a community.

  1. Parametric Dynamic Load Prediction of a Narrow Gauge Rocket Sled

    DTIC Science & Technology

    2006-12-01

    reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching...if it does not display a currently valid OMB control number. 1 . REPORT DATE DEC 2006 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND...what God has prepared for those who love Him.’ 1 Cor 2:9. v ACKNOWLEDGEMENTS I would like to acknowledge my advisor Dr. Gabe Garcia for his

  2. Blood changes during training and racing in sled dogs.

    PubMed

    Querengaesser, A; Iben, C; Leibetseder, J

    1994-12-01

    Six male and six female Alaskan Huskies allocated three by three to two teams fed rations slightly different in protein/fat ratio (A, 29.2: 53.7%; B, 34.1: 48.5% of digestible energy) were studied for hematological and metabolic changes during a complete training and racing season (24 wk). Blood variables [packed cell volume (PCV), red blood cell count (RBC), mean corpuscular volume, hemoglobin, total plasma protein, free fatty acids, cholesterol, lactic acid, creatine phosphokinase (CPK), creatinine, alanine aminotransferase (ALT) and aspartate aminotransferase (AST)] and six minerals were determined before (at rest) and immediately after a test run of 9 km and then 10, 20 and 30 min later, at the beginning of training as well as 7, 20 and 24 wk later. Training and exercise both significantly influenced PCV, RBC, creatinine and ALT and exercise influenced CPK. Only negligible differences were found between the diets.

  3. High-Performance Plastic Sled Design for Polar Traversing

    DTIC Science & Technology

    2015-06-01

    Traversing Jason C. Weale and James H. Lever Cold Regions Research and Engineering Laboratory (CRREL) U.S. Army Engineer Research and Development...and Sustainment Branch, Dr. Edel Cortez, Chief) of the U.S. Army Engineer Research and Development Center, Cold Regions Re- search and Engineering...Laboratory COTS Commercial Off the Shelf CRREL U.S. Army Cold Regions Research and Engineering Laboratory EAB Elongation at Break EPOLAR Engineering

  4. Predicting the Wear of High Speed Rocket Sleds

    DTIC Science & Technology

    2012-12-01

    25 2.5.1 SESAME tables...weighing the worn slider and comparing it to its initial state prior to the run. Some of his results are applicable to our studies, and are used as...for most situations, the vibrations are too small to notice. They exist in a static or quasistatic equilibrium. Application of forces can be described

  5. Operations and maintenance manual for the linear accelerator (sled)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The Linear Accelerator, a sliding chair which is pulled along a stationary platform in a horizontal axis is described. The driving force is a motor controlled by a velocity loop amplifier, and the mechanical link to the chair is a steel cable. The chair is moved in forward and reverse directions as indicated by the direction of motor rotation. The system operation is described with emphasis on the electronic control and monitoring functions. Line-by-line schematics and wire lists are included.

  6. The Development of a Horizontal Impact Sled Facility and Subsequent Crashworthiness Experiments

    DTIC Science & Technology

    1994-10-01

    A9 Figure 10: Relief Valve, Manual, Air Tanks A10 Figure 11: Safety Pin , Launch Station A10 Figure 12: Upper Probe Attach Points All Figure 13: Lower...POSITION; SAFETY PIN IS ENGAGED; AND, SAFETY INDICATOR IS GREEN. A-19 2.5 LAUNCH CHECK LIST NOTE At this time, all lab personnel, clieuts and observers are...Launch Station Refer to Figure 11. Apply power to SAFETY light assembly. Release light assembly relay by manually retracting SAFETY pin . GREEN light

  7. Brief communication: Transportation and trauma: Dog-sledding and vertebral compression in Alaskan Eskimos.

    PubMed

    Legge, Scott S

    2010-04-01

    Vertebral compression, as evidenced by compression of the centrum, was observed within two Native Alaskan skeletal samples. Information was collected from 1,071 and 656 vertebrae from Golovin Bay and Nunivak Island, Alaska, respectively. In addition, patterns of compression related vertebral change in each collection were characterized by sex and location within the vertebral column. The overall frequencies of vertebral compression were 3.6% (n = 721) at Golovin Bay and 1.7% (n = 403) at Nunivak Island for all observable thoracic and lumbar vertebrae (T1-L5). There was no statistically significant difference in the occurrence of compression among adults between these two collections. When examining the thoracic and lumbar vertebral segments by sex, females at Golovin Bay (4.5%; n = 442) exhibited a significantly higher frequency of vertebral compression than females at Nunivak (1.0%; n = 203). However, this difference in occurrence of compression could be accounted for by the age distributions of the two samples. No difference was noted between the males of the two collections. Compression frequencies in both samples are discussed in relation to the modes of transportation historically utilized by each community.

  8. Molecular Sleds and More: Novel Antiviral Agents via Single-Molecule Biology (441st Brookhaven Lecture)

    SciTech Connect

    Mangel, Wally

    2008-10-15

    Vaccines are effective against viruses such as polio and measles, but vaccines against other important viruses, such as HIV and flu viruses, may be impossible to obtain. These viruses change their genetic makeup each time they replicate so that the immune system cannot recognize all their variations. Hence it is important to develop new antiviral agents that inhibit virus replication. During this lecture, Dr. Mangel will discuss his group's work with a model system, the human adenovirus, which causes, among other ailments, pink eye, blindness and obesity. Mangel's team has developed a promising drug candidate that works by inihibiting adenovirus proteinase, an enzyme necessary for viral replication.

  9. Spatially resolved CO SLED of the Luminous Merger Remnant NGC 1614 with ALMA

    NASA Astrophysics Data System (ADS)

    Saito, Toshiki; Iono, Daisuke; Xu, Cong K.; Sliwa, Kazimierz; Ueda, Junko; Espada, Daniel; Kaneko, Hiroyuki; König, Sabine; Nakanishi, Kouichiro; Lee, Minju; Yun, Min S.; Aalto, Susanne; Hibbard, John E.; Yamashita, Takuji; Motohara, Kentaro; Kawabe, Ryohei

    2017-02-01

    We present high-resolution (1.″0) Atacama Large Millimeter/submillimeter Array (ALMA) observations of CO (1–0) and CO (2–1) rotational transitions toward the nearby IR-luminous merger NGC 1614 supplemented with ALMA archival data of CO (3–2) and CO (6–5) transitions. The CO (6–5) emission arises from the starburst ring (central 590 pc in radius), while the lower-J CO lines are distributed over the outer disk (∼3.3 kpc in radius). Radiative transfer and photon-dominated region (PDR) modeling reveals that the starburst ring has a single warmer gas component with more a intense far-ultraviolet radiation field ({n}{{{H}}2}∼ {10}4.6 cm‑3, {T}{kin}∼ 42 K, and {G}0∼ {10}2.7) relative to the outer disk ({n}{{{H}}2}∼ {10}5.1 cm‑3, {T}{kin}∼ 22 K, and {G}0∼ {10}0.9). A two-phase molecular interstellar medium with a warm and cold (>70 and ∼19 K) component is also an applicable model for the starburst ring. A possible source for heating the warm gas component is mechanical heating due to stellar feedback rather than PDR. Furthermore, we find evidence for non-circular motions along the north–south optical bar in the lower-J CO images, suggesting a cold gas inflow. We suggest that star formation in the starburst ring is sustained by the bar-driven cold gas inflow and that starburst activities radiatively and mechanically power the CO excitation. The absence of a bright active galactic nucleus can be explained by a scenario where cold gas accumulating on the starburst ring is exhausted as the fuel for star formation or is launched as an outflow before being able to feed to the nucleus.

  10. The AMT maglev test sled -- EML weapons technology transition to transportation

    SciTech Connect

    Schaaf, J.C. Jr.; Zowarka, R.C. Jr.; Davey, K.; Weldon, J.M.

    1997-01-01

    Technology spinoffs from prior electromagnetic launcher work enhance a magnetic levitation transportation system test bed being developed by American Maglev Technology of Florida. This project uses a series wound linear DC motor and brushes to simplify the magnetic levitation propulsion system. It takes advantage of previous related work in electromagnetic launcher technology to achieve success with this innovative design. Technology and knowledge gained from developments for homopolar generators and proposed railgun arc control are key to successful performance. This contribution supports a cost effective design that is competitive with alternative concepts. Brushes transfer power from the guideway (rail) to the vehicle (armature) in a novel design that activates the guideway only under the vehicle, reducing power losses and guideway construction costs. The vehicle carries no power for propulsion and levitation, and acts only as a conduit for the power through the high speed brushes. Brush selection and performance is based on previous EML homopolar generator research. A counterpulse circuit, first introduced in an early EML conference, is used to suppress arcing on the trailing brush and to transfer inductive energy to the next propulsion coil. Isolated static lift and preliminary propulsion tests have been completed, and integrated propulsion and lift tests are scheduled in early 1996.

  11. An experimental meat-free diet maintained haematological characteristics in sprint-racing sled dogs.

    PubMed

    Brown, Wendy Y; Vanselow, Barbara A; Redman, Andrew J; Pluske, John R

    2009-11-01

    A dog's nutrient requirements can theoretically be met from a properly balanced meat-free diet; however, proof for this is lacking. Exercise places additional demands on the body, and dogs fed a meat-free diet may be at increased risk of developing sports anaemia. We hypothesised that exercising dogs would remain in good health and not develop anaemia when fed a nutritionally balanced meat-free diet. To this end, twelve sprint-racing Siberian huskies were fed either a commercial diet recommended for active dogs (n 6), or a meat-free diet formulated to the same nutrient specifications (n 6). The commercial diet contained 43 % poultry meal, whereas soyabean meal and maize gluten made up 43 % of the meat-free diet, as the main protein ingredients. Dogs were fed these diets as their sole nutrient intake for 16 weeks, including 10 weeks of competitive racing. Blood samples were collected at weeks 0, 3, 8 and 16, and veterinary health checks were conducted at weeks 0, 8 and 16. Haematology results for all dogs, irrespective of diet, were within normal range throughout the study and the consulting veterinarian assessed all dogs to be in excellent physical condition. No dogs in the present study developed anaemia. On the contrary, erythrocyte counts and Hb values increased significantly over time (P < 0.01) in both groups of dogs. The present study is the first to demonstrate that a carefully balanced meat-free diet can maintain normal haematological values in exercising dogs.

  12. "Heavy Sledding": Barriers to Community Participation in Beaufort Sea Hydrocarbon Developments.

    ERIC Educational Resources Information Center

    Durst, Douglas

    1994-01-01

    This description of the Canadian government's assessment of the social impact of hydrocarbon exploration in the Arctic demonstrates barriers to citizen involvement: ad hoc nature, travel and child care problems, and lack of enough volunteers. Recommendations for community participation in impact assessment are given. (SK)

  13. Dog Sleds to Satellites: Library Service in the Land of the Midnight Sun.

    ERIC Educational Resources Information Center

    Herie, Euclid J.

    The role of the Canadian National Institute for the Blind (CNIB) in serving the aboriginal (indigenous) peoples of Canada, especially those in the Northwest Territories (NWT), is described, and the possibilities for future library delivery systems are discussed. The right of these peoples, and of all blind and visually impaired persons, to…

  14. From Dog Sled to Dial Phone: A Cultural Gap? -- The Far North.

    ERIC Educational Resources Information Center

    Dicks, Dennis

    1977-01-01

    Examines socioeconomic events surrounding major improvements in telephone service in the Eastern Canadian Arctic. Focuses on five towns at different stages of telecommunications development and relates the increased technology to air travel, use of the mail, changes in fur sales, changes in crime levels, and restructuring of communications…

  15. Evaluation of steering control devices in adapted cars using sled deceleration tests

    NASA Astrophysics Data System (ADS)

    Eixerés, B.; Masiá, J.; Dols, J. F.; Esquerdo, T. V.

    2009-11-01

    Steering control devices used by disabled drivers can reduce passive safety, interfering with the existing systems of safety in the vehicle or causing injury to the occupants [1]. In this article, the results obtained in different dynamic tests carried out in a crash test simulator are presented. These tests were carried out on the steering devices which interfere the most with the deployment of the driver's airbag and also with the knee airbag in a Citroen C5.

  16. Sled Dogs, Musher Math, and More: Theme Teaching and the Alaskan Iditarod.

    ERIC Educational Resources Information Center

    Park-Seldomridge, Anne

    1995-01-01

    A teacher of upper elementary deaf students describes a multidisciplinary study unit focused on the Alaskan dogsled race, the Iditarod. Activities included studying Alaskan geography and history, following specific racers (mushers) through daily updates faxed from Alaska, writing letters to mushers, calculating math facts related to the race,…

  17. Instrumentation package for a shrouded SWERVE/EPW rocket sled test

    SciTech Connect

    Garavaglia, E.G.

    1987-08-01

    A shrouded SWERVE test vehicle was instrumented and tested at MACH 3. The instrumentation consisted of accelerometers, pressure transducers, and event markers arranged in a nine-channel configuration. Data from the instrumentation were transmitted from the vehicle through an FM/FM telemetry system. Two fire sets and their associated command and controls were also included in this package. The event was recorded on high-speed color film, and the trajectory data were recorded by a laser tracker.

  18. Haemorrhagic pneumonia in sled dogs caused by Streptococcus equi subsp. zooepidemicus - one fatality and two full recoveries: a case report

    PubMed Central

    2013-01-01

    In spite of yearly vaccination, outbreaks of canine infectious respiratory disease are periodically seen amongst domestic dogs. These infections compromise host defense mechanisms, and, when combined with other stressful events, allow opportunistic pathogens like Streptococcus equi subsp. zooepidemicus to create serious disease. Early recognition and treatment are tremendously important for a successful outcome in these cases. A polyvalent vaccine was given to 22 racing dogs three days after a competition, followed by two days of rest, and then the dogs were returned to regular training. Coughing was noticed among the dogs four days after immunisation. Three days after this outbreak one of the dogs was unusually silent and was found dead the next morning. Simultaneously two other dogs developed haemorrhagic expectorate, depression and dyspnea and were brought in to the veterinary hospital. Streptococcus equi subsp. zooepidemicus was isolated in pure culture from all three cases. They were treated and rehabilitated successfully, and won a sledge race three months later. This paper discusses the necropsy results, treatment regime, rehabilitation and the chronology of vaccination, stressful events and disease. PMID:24020788

  19. The Physical Understanding of the Use of Coatings to Mitigate Hypervelocity Gouging Considering Real Test Sled Dimensions

    DTIC Science & Technology

    2004-09-01

    can only increase. This law describes irreversible processes. Written in the form of the Clausius- Duhem inequality, it places a limitation on internal...Plasticity , 20 (6) (2003). 82. Pascault, Jean- Pierre , et al. Thermosetting Polymers. New York, NY 10016: Marcel Dekker, Inc., 2002. 83. Washizu

  20. Static Force and Moment Test of the Holloman Narrow-Gage Rocket Sled at Mach Numbers from 3.5 to 5.5.

    DTIC Science & Technology

    1987-09-01

    N 4NN Lc t- * * -~~ c. 2 0 0 a CL v W" *7 m V4 r4 𔃾A r4N r14.O 4 .F- X .b .b . .. CC!I a. . . -t- 9.9.. L2 In V Lobbl Ul dd lbI a.. 0. 418n nInI - F...00 0 U2 *SSSIC d in cot N 4r ~ 0 ~300 00 00 NI , 61’ AinI *V- -n r-0. wo W) a, C𔃾N 4-~~ O0 0 Uk r. In 0 0 01000c 100 ninI u I- CLa a *Z * 4a 4 C4 t

  1. Final Evaluation of Rain Erosion Sled Test Results at Mach 3.7 to 5.0 for Slip-Cast Fused Silica Radome Structures

    DTIC Science & Technology

    1979-03-06

    Georgia Institute of Technology had invar washers bonded to each end of the samples.This concept was incorporated, but 47 asbestos phenolic was...Radomes, Final Technical Report, Pro- ject A-925, Contract DA-01-021-AMC 14464(2), Georgia Institute of Tech- nology, Atlanta, Georgia , March 1967. 4...Watertown, Massachusetts 02172 Commander Naval Weapons Center Aerothermodynamics Branch (Code 4061) ATTN: Mr. C. F. Markarian 1 China Lake

  2. Measurements of Blast Pressures on a Rigid 35 deg Sweptback Wing at Mach 0.76 from Rocket Propelled Sled Tests.

    DTIC Science & Technology

    1980-01-31

    inches Root Chord (at model centerline) 15.091 Wing Section (streamwise) 64A010 Thickness Ratio (at model centerline) 17% (at tip) 10% Pressure Stations...Theoretical Symmetric Span Loading at Subsonic Speeds for Wings Having Arbitrary Planforms, NACA , Report No. 921, 1948. 95 APPENDIX A PRESSURE

  3. 5. BUILDING 0503, INTERIOR WOODEN ARCHES. Looking south from entrance. ...

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

    5. BUILDING 0503, INTERIOR WOODEN ARCHES. Looking south from entrance. - Edwards Air Force Base, South Base Sled Track, Earth Covered Bunker Types, North of Sled Track, Lancaster, Los Angeles County, CA

  4. 3. BUILDING 0503, NORTH FRONT AND WEST SIDE, WITH LOADING ...

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

    3. BUILDING 0503, NORTH FRONT AND WEST SIDE, WITH LOADING DOCK AND GABLE ROOFED SHED. - Edwards Air Force Base, South Base Sled Track, Earth Covered Bunker Types, North of Sled Track, Lancaster, Los Angeles County, CA

  5. 2. BUILDING 0521, SOUTH REAR AND EAST SIDE. Looking to ...

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

    2. BUILDING 0521, SOUTH REAR AND EAST SIDE. Looking to northwest from access road. - Edwards Air Force Base, South Base Sled Track, Earth Covered Bunker Types, North of Sled Track, Lancaster, Los Angeles County, CA

  6. Low-Density Supersonic Decelerator Test

    NASA Video Gallery

    NASA recently performed a trial run on a rocket sled test fixture, powered by rockets, to replicate the forces a supersonic spacecraft would experience prior to landing. The sled tests will allow t...

  7. NORTH SIDE FACING TRACK, SHOWING ELECTRICAL BOX AND CONCRETE VAULT ...

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

    NORTH SIDE FACING TRACK, SHOWING ELECTRICAL BOX AND CONCRETE VAULT - Edwards Air Force Base, South Base Sled Track, Electrical Distribution Station, South side of Sled Track, Lancaster, Los Angeles County, CA

  8. 3. SOUTH SIDE. Edwards Air Force Base, South Base ...

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

    3. SOUTH SIDE. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  9. 6. OUTER BLAST DOOR, WEST REAR. Edwards Air Force ...

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

    6. OUTER BLAST DOOR, WEST REAR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  10. 5. NORTH SIDE AND WEST REAR. Edwards Air Force ...

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

    5. NORTH SIDE AND WEST REAR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  11. Gravity Slides With Magnetic Braking

    NASA Technical Reports Server (NTRS)

    Goodrick, Thomas F.

    1995-01-01

    Slides with magnetic braking enable safe emergency descent from tall buildings, fire-truck ladders, towers, and like. According to concept, slide includes sled that moves along stationary aluminum track tilted against top of building. Sled holds set of permanent magnets at preset small distance from surface of track. Passenger stands on, sits on, or strapped to platform on sled. Release device at top of slide holds sled in place until passenger prepared for descent.

  12. 10. ENTRY STAIRWELL TO CABLE TUNNEL, ABOUT THREE QUARTERS THE ...

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

    10. ENTRY STAIRWELL TO CABLE TUNNEL, ABOUT THREE QUARTERS THE DISTANCE TO THE SLED LAUNCHING PAD FROM THE FIRING CONTROL BLOCKHOUSE 0545. Looking west northwest. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

  13. A Front-Row Seat at a Wheelchair Crash Test: EP Kicks Off Its Wheelchair Transportation Safety Series with a Visit to the University of Michigan's Transportation Research Institute

    ERIC Educational Resources Information Center

    Hollingsworth, Jan Carter

    2007-01-01

    The centerpiece of the University of Michigan's Transportation Research Institute (UMTRI) Sled Lab is "the impact sled," as it is called in the business. It's the business of conducting sled impact tests, perhaps better known as crash tests, on all types of wheelchairs and wheelchair seating systems as well as wheelchair tiedowns and…

  14. Effects of resisted sprint training on acceleration in professional rugby union players.

    PubMed

    West, Daniel J; Cunningham, Dan J; Bracken, Richard M; Bevan, Huw R; Crewther, Blair T; Cook, Christian J; Kilduff, Liam P

    2013-04-01

    The use of weighted sled towing as a training tool to improve athlete acceleration has received considerable attention; however, its effectiveness for developing acceleration is equivocal. This study compared the effects of combined weighted sled towing and sprint training against traditional sprint training on 10 and 30 m speed in professional rugby union players (n = 20). After baseline testing of 10 and 30 m speed, participants were assigned to either the combined sled towing and sprint training (SLED) or traditional sprint training (TRAD) groups, matched for 10-m sprint times. Each group completed 2 training sessions per week for 6 weeks, with performance reassessed post-training. Both training programmes improved participants' 10 and 30 m speed (p < 0.001), but the performance changes (from pre to post) in 10 m (SLED -0.04 ± 0.01 vs. TRAD -0.02 ± 0.01 seconds; p < 0.001) and 30 m (SLED -0.10 ± 0.03 vs. TRAD -0.05 ± 0.03 seconds; p = 0.003) sprint times were significantly greater in the SLED training group. Similarly, the percent change within the SLED group for the 10 m (SLED -2.43 ± 0.67 vs. TRAD -1.06 ± 0.80 seconds; p = 0.003) and 30 m (SLED -2.46 ± 0.63 vs. TRAD -1.15 ± 0.72 seconds; p = 0.003) tests were greater than the TRAD group. In conclusion, sprint training alone or combined with weighted sled towing can improve 10 and 30 m sprint times; however, the latter training method promoted greater improvements in a group of professional rugby players.

  15. 24. "GAFFTC 29 SEP 60, F106B STATIC TEST 1." Test ...

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

    24. "G-AFFTC 29 SEP 60, F-106B STATIC TEST 1." Test of the Convair sled escape system at static test site east of Station "50". File no. 11,988-60. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  16. 13. WALKWAY FROM LAUNCHING PAD TO CABLE TUNNEL STAIRWELL, ALSO ...

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

    13. WALKWAY FROM LAUNCHING PAD TO CABLE TUNNEL STAIRWELL, ALSO SHOWING A PROTECTIVE BERM AT TOP LEFT, AND FIRING CONTROL BLOCKHOUSE 0545 AT TOP RIGHT. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

  17. 1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION ...

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

    1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION TOWER. WATER BRAKE TROUGH SEGMENT AT LOWER RIGHT. Looking north northeast. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  18. 9. A VIEW ALONG WEST REAR WALL SHOWING CONFIGURATION FOR ...

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

    9. A VIEW ALONG WEST REAR WALL SHOWING CONFIGURATION FOR OBSERVATION MIRRORS. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  19. 2. OBLIQUE VIEW OF WEST FRONT. The frames on an ...

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

    2. OBLIQUE VIEW OF WEST FRONT. The frames on an angle originally held mirrors for viewing the tests from inside the building. Vertical frame originally held bullet glass. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

  20. 8. INTERIOR, CONTROL AND INSTRUMENTATION ROOM. Looking southwest toward entrance ...

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

    8. INTERIOR, CONTROL AND INSTRUMENTATION ROOM. Looking southwest toward entrance and inner blast door. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  1. 4. EAST FRONT. Original viewing windows on upper level have ...

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

    4. EAST FRONT. Original viewing windows on upper level have been filled in with concrete block. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  2. 7. BULLET GLASS OBSERVATION WINDOW AT GROUND LEVEL ON WEST ...

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

    7. BULLET GLASS OBSERVATION WINDOW AT GROUND LEVEL ON WEST REAR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  3. 2. WEST REAR, WITH PORTHOLE ESCAPE HATCH ABOVE ENTRY DOOR. ...

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

    2. WEST REAR, WITH PORTHOLE ESCAPE HATCH ABOVE ENTRY DOOR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  4. Sustained low-efficiency dialysis in septic shock: Hemodynamic tolerability and efficacy

    PubMed Central

    Mishra, Shakti Bedanta; Singh, Ratender Kumar; Baronia, Arvind Kumar; Poddar, Banani; Azim, Afzal; Gurjar, Mohan

    2016-01-01

    Aim of the Study: Acute kidney injury (AKI) in septic shock has poor outcomes. Sustained low-efficiency dialysis (SLED) is increasingly replacing continuous renal replacement therapy as the preferred modality in Intensive Care Units (ICUs). However, the essential aspects of hemodynamic tolerability and efficacy of SLED in septic shock AKI has been minimally studied. Patients and Methods: We describe hemodynamic tolerability using modified vasopressor index (VI) and vasopressor dependency (VD) and efficacy using a combination of Kt/v, correction of acidosis, electrolyte, and fluid overload. Adult ICU patients of septic shock in AKI requiring SLED were included in this study. Results: One hundred and twenty-four patients of septic shock AKI requiring SLED were enrolled in the study. There were 74 nonsurvivors (NSs). Approximately, 56% (278/498) of the sessions in which vasopressors were required were studied. Metabolic acidosis (49%) was the predominant indication for the initiation of SLED in these patients. Baseline characteristics between survivors and NSs were comparable, except for age, severity scores, AKI stage, and coexisting illness. VI and VD prior to the initiation of SLED and delta VI and VD during SLED were significantly higher in NSs. Hemodynamic tolerability and efficacy of SLED was achievable only at lower vasopressor doses. Conclusion: VI, VD, and combination of Kt/v together with correction of acidosis, electrolyte, and fluid overload can be used to describe hemodynamic tolerability and efficacy of SLED in septic shock AKI. However, at higher vasopressor doses in septic shock, hemodynamic tolerability and efficacy of SLED requires further evidence. PMID:28149027

  5. Pharmacokinetics of fluconazole in critically ill patients with acute kidney injury receiving sustained low-efficiency diafiltration.

    PubMed

    Sinnollareddy, Mahipal G; Roberts, Michael S; Lipman, Jeffrey; Robertson, Thomas A; Peake, Sandra L; Roberts, Jason A

    2015-02-01

    Fluconazole is a widely used antifungal agent in critically ill patients. It is predominantly (60-80%) excreted unchanged in urine. Sustained low-efficiency diafiltration (SLED-f) is increasingly being utilised in critically ill patients because of its practical advantages over continuous renal replacement therapy. To date, the effect of SLED-f on fluconazole pharmacokinetics and dosing has not been studied. The objective of this study was to describe the pharmacokinetics of fluconazole in critically ill patients with acute kidney injury receiving SLED-f and to compare this with other forms of renal replacement therapy. Serial blood samples were collected at pre- and post-filter ports within the SLED-f circuit during SLED-f and from an arterial catheter before and after SLED-f from three patients during one session. Fluconazole concentrations were measured using a validated chromatography method. Median clearance (CL) and 24-h area under the concentration-time curve (AUC0-24) were 2.1L/h and 152 mg·h/L, respectively, whilst receiving SLED-f. Moreover, 72% of fluconazole was cleared by a single SLED-f session (6h) compared with previous reports of 33-38% clearance by a 4-h intermittent haemodialysis session. CL and AUC0-24 were comparable with previous observations in a pre-dilution mode of continuous venovenous haemodiafiltration. The observed rebound concentration of fluconazole post SLED-f was <2%. Although a definitive dosing recommendation is not possible due to the small patient number, it is clear that doses >200mg daily are likely to be required to achieve the PK/PD target for common pathogens because of significant fluconazole clearance by SLED-f.

  6. Efficacy and Safety of a Citrate-Based Protocol for Sustained Low-Efficiency Dialysis in AKI Using Standard Dialysis Equipment

    PubMed Central

    Regolisti, Giuseppe; Cademartiri, Carola; Cabassi, Aderville; Picetti, Edoardo; Barbagallo, Maria; Gherli, Tiziano; Castellano, Giuseppe; Morabito, Santo; Maggiore, Umberto

    2013-01-01

    Summary Background and objectives A simple anticoagulation protocol was developed for sustained low-efficiency dialysis (SLED) in patients with AKI, based on the use of anticoagulant citrate dextrose solution formulation A (ACD-A) and standard dialysis equipment. Patients’ blood recalcification was obtained from calcium backtransport from dialysis fluid. Design, setting, participants, & measurements All patients treated with SLED (8- to 12-hour sessions) for AKI in four intensive care units of a university hospital were studied over a 30-month period, from May 1, 2008 to September 30, 2010. SLED interruptions and their causes, hemorrhagic complications, as well as coagulation parameters, ionized calcium, and blood citrate levels were recorded. Results This study examined 807 SLED sessions in 116 patients (mean age of 69.7 years [SD 12.1]; mean Acute Physiology and Chronic Health Evaluation II score of 23.8 [4.6]). Major bleeding was observed in six patients (5.2% or 0.4 episodes/100 person-days follow-up while patients were on SLED treatment). Citrate accumulation never occurred, even in patients with liver dysfunction. Intravenous calcium for ionized hypocalcemia (< 3.6 mg/dl or < 0.9 mmol/L) was needed in 28 sessions (3.4%); in 8 of these 28 sessions (28.6%), low ionized calcium was already present before SLED start. In 92.6% of treatments, SLED was completed within the scheduled time (median 8 hours). Interruptions of SLED by impending/irreversible clotting were recorded in 19 sessions (2.4%). Blood return was complete in 98% of the cases. In-hospital mortality was 45 of 116 patients (38.8%). Conclusions This study protocol affords efficacious and safe anticoagulation of the SLED circuit, avoiding citrate accumulation and, in most patients, systematic calcium supplementation; it can be implemented with commercial citrate solutions, standard dialysis equipment, on-line produced dialysis fluid, and minimal laboratory monitoring. PMID:23990164

  7. What does autonomic arousal tell us about locomotor learning?

    PubMed

    Green, D A; Bunday, K L; Bowen, J; Carter, T; Bronstein, A M

    2010-09-29

    Walking onto a stationary sled previously experienced as moving induces locomotor aftereffects (LAE, or "broken escalator phenomenon"). This particular form of aftereffect can develop after a single adaptation trial and occurs despite subjects being fully aware that the sled will not move. Here, we investigate whether such strong LAE expression may relate to arousal or fear related to instability during the gait adaptation process. Forty healthy subjects were allocated to three sled velocity groups; SLOW (0.6 m/s), MEDIUM (1.3 m/s), or FAST (2.0 m/s). Subjects walked onto the stationary sled for five trials (BEFORE), then onto the moving sled for 15 trials (adaptation or MOVING trials) and, finally, again onto the stationary sled for five trials (AFTER). Explicit warning regarding sled status was given. Trunk position, foot-sled contact timing, autonomic markers (electrodermal activity [EDA], ECG, respiratory movements) in addition to self-reported task-related confidence and state/trait anxiety were recorded. Trunk sway, EDA, and R-R interval shortening were greatest during the first MOVING trial (MOVING_1), progressively attenuating during subsequent MOVING trials. A LAE, recorded as increased gait velocity and trunk sway during AFTER_1, occurred in both MEDIUM and FAST sled velocity groups. The amplitude of forward trunk sway in AFTER_1 (an indicator of aftereffect magnitude) was related to EDA during the final adaptation trial (MOVING_15). AFTER_1 gait velocity (also an indicator of aftereffect magnitude) was related to MOVING_1 trunk sway. Hence, gait velocity and trunk sway components of the LAE are differentially related to kinematic and autonomic parameters during the early and late adaptation phase. The finding that EDA is a predictor of LAE expression indicates that autonomic arousal or fear-based mechanisms can promote locomotor learning. This could in turn explain some unusual characteristics of this LAE, namely its resistance to explicit knowledge and

  8. H-60A/L Passenger Airbag Protection: Vertical and Horizontal Impact Tests

    DTIC Science & Technology

    2013-04-30

    and a custom-made rigid seat. The manikins included a 50th percentile Hybrid III (HB50) and a large male manikin (LARD – Largest Anthropometric...consists of a 4 ft by 8 ft sled positioned on a 204 ft long track and is accelerated using a 24 inch diameter pneumatic actuator. The HIA operates on...sled breaks contact with the thrust piston, the sled coasts to a stop or is stopped with a triggered pneumatic brake system. The impact acceleration

  9. Spacelab Life Sciences-1 electrical diagnostic expert system

    NASA Technical Reports Server (NTRS)

    Kao, C. Y.; Morris, W. S.

    1989-01-01

    The Spacelab Life Sciences-1 (SLS-1) Electrical Diagnostic (SLED) expert system is a continuous, real time knowledge-based system to monitor and diagnose electrical system problems in the Spacelab. After fault isolation, the SLED system provides corrective procedures and advice to the ground-based console operator. The SLED system updates its knowledge about the status of Spacelab every 3 seconds. The system supports multiprocessing of malfunctions and allows multiple failures to be handled simultaneously. Information which is readily available via a mouse click includes: general information about the system and each component, the electrical schematics, the recovery procedures of each malfunction, and an explanation of the diagnosis.

  10. 30 CFR 57.12014 - Handling energized power cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... potentials in excess of 150 volts, phase-to-ground, shall not be moved with equipment unless sleds or slings, insulated from such equipment, are used. When such energized cables are moved manually, insulated...

  11. 30 CFR 57.12014 - Handling energized power cables.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... potentials in excess of 150 volts, phase-to-ground, shall not be moved with equipment unless sleds or slings, insulated from such equipment, are used. When such energized cables are moved manually, insulated...

  12. Cold, Ice, and Snow Safety (For Parents)

    MedlinePlus

    ... be outdoors for a while. previous continue Winter Sports Safety If your kids decide to go sledding ... safety smarts, too. Make sure your kids avoid sports injuries by wearing helmets during ice hockey games ...

  13. 48. Exterior detail of Marine Railway #1. Note rail/roller type ...

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

    48. Exterior detail of Marine Railway #1. Note rail/roller type (wood beam with steel plate for railway/rollers on sled) and removable catwalk on bed. - Barbour Boat Works, Tryon Palace Drive, New Bern, Craven County, NC

  14. SOUTHEAST FRONT AND NORTHEAST SIDE. Looking northwest from top of ...

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

    SOUTHEAST FRONT AND NORTHEAST SIDE. Looking northwest from top of protective berm - Edwards Air Force Base, South Base Sled Track, Water Pump Station, Area "O" at east end, northwest of fuel storage, Lancaster, Los Angeles County, CA

  15. 76 FR 77552 - Certain Light-Emitting Diodes and Products Containing Same; Determination Not To Review an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-13

    ... August 18, 2011, based on a ] complaint filed by SLED. 76 FR 51396-97 (Aug. 18, 2011). A corrected Notice... Investigations will not participate as a party in this investigation. 76 FR 52348-49 (Aug. 22, 2011)....

  16. 50 CFR 622.41 - Species specific limitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... operator of the harvesting vessel must provide the following information to the NMFS Office for Law... connected to a sled, door, or other device that spreads the net, or to a tow rope, cable, pole, or...

  17. X-Band Active-Passive Rf Pulse Compressor with Plasma Switches

    SciTech Connect

    Vikharev, A.L.; Ivanov, O.A.; Gorbachev, A.M.; Lobaev, M.A.; Isaev, V.A.; Tantawi, S.G.; Lewandowski, J.R.; Hirshfield, J.L.; /Omega-P, New Haven /Yale U.

    2012-04-27

    As proposed by SLAC, the efficiency of a pulse compressor of the SLED-II type could be increased by changing both the phase of the microwave source and the coupling coefficient of the delay line. In the existing SLED-II system at frequency 11.4 GHz, the resonant delay line is coupled with the source via an iris with a constant reflection coefficient. Replacement of the iris with an active component makes it possible to create an active SLED-II system. In this paper, the use of plasma switches as the active elements is discussed. Plasma switches have been developed and tested at a high-power level for production of flattop compressed pulses. Active switching of SLED-II has demonstrated a marked increase in efficiency (by 20%) and power gain (by 37%) as compared with passive switching. The active compressor has produced 173 ns rf flattop output pulses with a power of about 112 MW.

  18. Learning the "Wright' Way to Fly!

    NASA Video Gallery

    This lesson uses the online NASA CONNECT™™: The "Wright" Math Educator Guide, the NASA Aeronautics Activity Guide and the Sled Kite activity to help students learn how the Wright brothers developed...

  19. 14. "FIRING CONTROL BLOCKHOUSE; STATION '0' AREA; PLAN, ELEVATIONS, SECTION, ...

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

    14. "FIRING CONTROL BLOCKHOUSE; STATION '0' AREA; PLAN, ELEVATIONS, SECTION, DETAIL AND SCHED." Specifications No. ENG-04-353-57-75; Drawing No. AF-60-09-15; sheet 21 of 96; D.O. Series No. AF 1394/39, Rev. A. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 5296 Rev. A, Date: 11/17/59. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

  20. 15. "FIRING CONTROL BLOCKHOUSE; STATION '0' AREA; PLAN, AND SECTIONS." ...

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

    15. "FIRING CONTROL BLOCKHOUSE; STATION '0' AREA; PLAN, AND SECTIONS." Specifications No. ENG-04-353-57-75; Drawing No. AF-60-09-15; sheet 40 of 96; D.O. Series No. AF 1394/60, Rev. A. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 5296 Rev. A, Date: 11/17/59. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

  1. Glatz Prototype Seat Impact Testing

    DTIC Science & Technology

    2013-07-03

    all PH testing. The HIA consists of a 4 ft by 8 ft sled positioned on a 204 ft long track and is accelerated using a 24 inch diameter pneumatic ...thrust piston, the sled coasts to a stop or is stopped with a triggered pneumatic brake system. The impact acceleration is roughly sinusoidal. HIA... Hybrid III Aerospace manikin (HB50) representing a mid-sized male, and a Large Anthropomorphic Research Device (LARD) manikin representing a large male

  2. Programmatic Environmental Assessment High Speed Test Track (HSTT) Operations Holloman Air Force Base, New Mexico

    DTIC Science & Technology

    2007-09-01

    53 4.7 BASH (Test Sled-Wildlife Collisions) and Oryx Management .............................. 58 4.8 Pest and Bat...lined pool for cooling rocket blasts. This pool is no longer used because it leaks, and is fenced because it can also trap oryx . The rail survey...immediate area of sled operations to place and operate data collection instruments for tests and to harass oryx into moving out of critical test

  3. Vehicle Maintenance Manpower Requirements for U.S. Army Installation Directorates of Engineering and Housing Based on Air Force, Navy, and Army Reserves’ Staffing Techniques.

    DTIC Science & Technology

    1986-07-01

    monitors repair cycle asset. 2. Tool Crib. Issues and receives tools upon request; maintains suspense file; inspects and maintains tools; schedules...request; maintains suspense file; inspects and maintains tools; schedules precision measurement equipment (PME); performs tool crib inventory. 13. Workload...SCOOT PK 3-4WHL SCOOTER , MOTOR, PKG DELIVERY, 3-4 WHEEL WITH SIDE CAR 0907 Z SLED SNOWMOBILE SLED, SELF-PROP, GED, SNOWMOB, SKI-STEER 5820 S TRK COMPAC

  4. 26. "AIR INSTALLATIONS; EDWARDS AIR FORCE BASE, CALIFORNIA; HIGH SPEED ...

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

    26. "AIR INSTALLATIONS; EDWARDS AIR FORCE BASE, CALIFORNIA; HIGH SPEED TEST TRACK." Drawing No. 10-259. One inch to 400 feet plan of original 10,000-foot sled track. No date. No D.O. series number. No headings as above. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  5. Impact Acceleration Response of the Selspot Motion Analysis System and an Endevco Angular Accelerometer

    DTIC Science & Technology

    1990-02-01

    consists of caliper brakes which grip the track rails when activated by onboard compressed nitrogen gas. The track rails are one inch thick and the total...coasting or by brake application. Various acceleration profiles may be obtained by changing the differential pressures, the travel length of the...thrust assembly and the metering structure on the thrust piston. The sled glides along the track rails on 21 twelve glide pads. The sled braking system

  6. Using head-on collisions to compare risk of driver death by frontal air bag generation: a matched-pair cohort study.

    PubMed

    Braver, Elisa R; Kufera, Joseph A; Alexander, Melvin T; Scerbo, Marge; Volpini, Karen; Lloyd, Joseph P

    2008-03-01

    US air bag regulations were changed in 1997 to allow tests of unbelted male dummies in vehicles mounted and accelerated on sleds, resulting in longer crash pulses than rigid-barrier crashes. This change facilitated depowering of frontal air bags and was intended to reduce air bag-induced deaths. Controversy ensued as to whether sled-certified air bags could increase adult fatality risk. A matched-pair cohort study of two-vehicle, head-on, fatal collisions between drivers involving first-generation versus sled-certified air bags during 1998-2005 was conducted by using Fatality Analysis Reporting System data. Sled certification was ascertained from public information and a survey of automakers. Conditional Poisson regression for matched-pair cohorts was used to estimate risk ratios adjusted for age, seat belt status, vehicle type, passenger car size, and model year for driver deaths in vehicles with sled-certified air bags versus first-generation air bags. For all passenger-vehicle pairs, the adjusted risk ratio was 0.87 (95% confidence interval: 0.77, 0.98). In head-on collisions involving only passenger cars, the adjusted risk ratio was 1.04 (95% confidence interval: 0.85, 1.29). Increased fatality risk for drivers with sled-certified air bags was not observed. A borderline significant interaction between vehicle type and air bag generation suggested that sled-certified air bags may have reduced the risk of dying in head-on collisions among drivers of pickup trucks.

  7. Implementation and validation of thoracic side impact injury prediction metrics in a human body model.

    PubMed

    Golman, Adam J; Danelson, Kerry A; Gaewsky, James P; Stitzel, Joel D

    2015-08-01

    This study's purpose was to implement injury metrics into the Total Human Model for Safety (THUMS) mirroring the spinal accelerometers, rib accelerometers and chest band instrumentation from two lateral post-mortem human subject sled test configurations. In both sled configurations, THUMS contacted a flat rigid surface (either a wall or beam) at 6.7 m/s. Sled A maximum simulated wall forces for the thorax, abdomen and pelvis were 7.1, 5.0 and 10.0 kN versus 5.7 ± 0.8, 3.4 ± 1.2 and 6.2 ± 2.7 kN experimentally. Sled B maximum simulated beam forces for the torso and pelvis were 8.0 and 7.6 kN versus 8.5 ± 0.2 and 7.9 ± 2.5 kN experimentally. Quantitatively, force magnitude contributed more to variation between simulated and experimental forces than phase shift. Acceleration-based injury metrics were within one standard deviation of experimental means except for the lower spine in the rigid wall sled test. These validated metrics will be useful for quantifying occupant loading conditions and calculating injury risks in various loading configurations.

  8. Development and validation of a computer crash simulation model of an occupied adult manual wheelchair subjected to a frontal impact.

    PubMed

    Dsouza, R; Bertocci, G

    2010-04-01

    Wheelchairs are primarily designed for mobility and are not necessarily intended for use as motor vehicle seats. However, many wheelchairs serve as vehicle seats for individuals unable to transfer to a vehicle seat. Subjecting wheelchairs to sled testing, in part establishes the crashworthiness of wheelchairs used as motor vehicle seats. Computer simulations provide a supplemental approach for sled testing, to assess wheelchair response and loading under crash conditions. In this study a nonlinear, dynamic, computer model was developed and validated to simulate a wheelchair and occupant subjected to a frontal impact test (ANSI/RESNA WC19). This simulation model was developed utilizing data from two frontal impact 20 g/48 km/h sled tests, which consisted of identical, adult manual wheelchairs secured with 4-point tiedowns, occupied with a 50th percentile adult male anthropomorphic test device (ATD), restrained with a 3-point occupant restraint system. Additionally, the model was validated against sled data using visual comparisons of wheelchair and occupant kinematics, along with statistical assessments of outcome measures. All statistical evaluations were found to be within the acceptance criteria, indicating the model's high predictability of the sled tests. This model provides a useful tool for the development of crashworthy wheelchair design guidelines, as well as the development of transit-safe wheelchair technologies.

  9. Gastritis and Gastric Ulcers in Working Dogs.

    PubMed

    Davis, Michael S; Williamson, Katherine K

    2016-01-01

    Gastritis and gastric ulcers are an important cause of morbidity and mortality in canine athletes. Although the majority of scientific work on this condition has been performed in ultraendurance racing sled dogs, this condition has been identified in other canine athletes, including sled dogs competing in shorter events and dogs performing off-leash explosive detection duties. The cause of the syndrome is unknown, but current hypotheses propose a link between exercise-induced hyperthermia and loss of gastric mucosal barrier function as an early event in the pathogenesis. Treatment is focused on prevention of clinical disease using acid secretion inhibitors, such as omeprazole, which has excellent efficacy in controlled clinical studies.

  10. Vertical Impact Tests of Humans and Anthropomorphic Manikins

    DTIC Science & Technology

    1991-04-01

    ADAM E A K 45 A C C 30 : E L N ~- I j’ G 0 10 12 14 16 18 20 22...75 A 7 -- cG-- N -cl SmaII ADAM P-- a-- ICGc- 95 P 60 13- Large ADAM - E A A . E 30 L N 10 12 14 16 18 20 22 24 SLED ACCELER.TION LEVEL (G) FIGURE 8...ADAM 8 6 CG-95 p 0•- Large ADAM -- E K 6 N L a 0-- 00 12 14 id is 20 22 24 SLED ACCELCRATION LEVEL (G) FIGUI’E 10. RESULTANT SEAT rORCE VS.

  11. Test Capabilities Revitalization at the Aerial Cable Test Facility, Sandia National Laboratories, New Mexico

    DTIC Science & Technology

    2003-06-01

    AFFECTED ENVIRONMENT 3.1 History The original aerial cable, installed in 1971, was a 1 3/8-inch wire rope spanning a 5,000-ft-wide canyon. A rocket sled... cableways . 3.2 Air Quality Ambient air quality is regulated by the joint Albuquerque-Bernalillo County-Air Quality Control Board (ABC/AQCB). The ABC

  12. Understanding Complex Ecologies: An Investigation of Student Experiences in Adventure Learning Programs

    ERIC Educational Resources Information Center

    Koseoglu, Suzan; Doering, Aaron

    2011-01-01

    The GoNorth! Adventure Learning (AL) Series delivered educational programs about global climate change and sustainability from 2006 to 2010 via a hybrid-learning environment that included a curriculum designed with activities that worked in conjunction with the travels of Team GoNorth! as they dog sledded throughout the circumpolar Arctic. This…

  13. 36 CFR 1002.19 - Winter activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing, tobogganing and similar winter sports are prohibited on Presidio Trust roads and in parking areas open to... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Winter activities....

  14. 36 CFR 2.19 - Winter activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing, tobogganing and similar winter sports are prohibited on park roads and in... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Winter activities....

  15. STEMEdhub: Supporting STEM Education Initiatives via the HUBzero Platform

    ERIC Educational Resources Information Center

    Lehman, James D.; Ertmer, Peggy A.; Bessenbacher, Ann M.

    2015-01-01

    Built as one of 60+ hubs on the HUBzero platform, STEMEdhub was developed in 2011 as a resource for research, education, and collaboration in STEM education. The hub currently supports 82 different groups. In this article, the authors describe two specific groups (SLED and AAU) that are taking advantage of numerous communication and resource tools…

  16. 52. Exterior view of yard at marine railway #2. Not ...

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

    52. Exterior view of yard at marine railway #2. Not rail/roller type (wood beam with steel plate rail on sled/roller railway). Steel fabrication building and traveling crane in background. - Barbour Boat Works, Tryon Palace Drive, New Bern, Craven County, NC

  17. A novel in vivo impact device for evaluation of sudden limb loading response.

    PubMed

    Boutwell, Erin; Stine, Rebecca; Gard, Steven

    2015-01-01

    The lower limbs are subjected to large impact forces on a daily basis during gait, and ambulators rely on various mechanisms to protect the musculoskeletal system from these potentially damaging shocks. However, it is difficult to assess the efficacy of anatomical mechanisms and potential clinical interventions on impact forces because of limitations of the testing environment. The current paper describes a new in vivo measurement device (sudden loading evaluation device, or SLED) designed to address shortcomings of previous loading protocols. To establish the repeatability and validity of this testing device, reliability and human participant data were collected while the stiffnesses of simulated and prosthetic limbs were systematically varied. The peak impact forces delivered by the SLED ranged from 706±3 N to 2157±32 N during reliability testing and from 784±30 N to 938±18 N with the human participant. The relatively low standard deviations indicate good reliability within the impacts delivered by the SLED, while the magnitude of the loads experienced by the human participant (98-117% BW) were comparable to ground reaction forces during level walking. Thus, the SLED may be valuable as a research tool for investigations of lower-limb impact loading events.

  18. Environmental Assessment for Demolition of Buildings 113, 130, 141, (West Wing), 256, 257, and the Boresight Tower at New Boston Air Force Station, New Hampshire

    DTIC Science & Technology

    2010-09-01

    The bedrock geology underlying NBAFS consists of Pre-Quaternary metamorphic and igneous rocks . Generally, the bedrock is buried beneath glacial...fishing, swimming, camping, hiking, rock climbing, hunting, archery, boating, cross-country skiing, ice fishing, ice skating, sledding, and snowmobiling

  19. 75 FR 50958 - Federal Motor Vehicle Safety Standards; Motorcoach Definition; Occupant Crash Protection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... Standards; Motorcoach Definition; Occupant Crash Protection AGENCY: National Highway Traffic Safety.... Stage 2: Frontal Sled Tests VI. Proposed Requirements a. Adding a Definition of ``Motorcoach'' to 49 CFR... to: Add a definition of ``motorcoach'' to 49 CFR Part 571.3; Amend FMVSS No. 208, ``Occupant...

  20. CO Spectral Line Energy Distributions in Galactic Sources: Empirical Interpretation of Extragalactic Observations

    NASA Astrophysics Data System (ADS)

    Indriolo, Nick; Bergin, E. A.; Goicoechea, J. R.; Cernicharo, J.; Gerin, M.; Gusdorf, A.; Lis, D. C.; Schilke, P.

    2017-02-01

    The relative populations in rotational transitions of CO can be useful for inferring gas conditions and excitation mechanisms at work in the interstellar medium. We present CO emission lines from rotational transitions observed with Herschel/HIFI in the star-forming cores Orion S, Orion KL, Sgr B2(M), and W49N. Integrated line fluxes from these observations are combined with those from Herschel/PACS observations of the same sources to construct CO spectral line energy distributions (SLEDs) from 5 ≤ J u ≤ 48. These CO SLEDs are compared to those reported in other galaxies, with the intention of empirically determining which mechanisms dominate excitation in such systems. We find that CO SLEDs in Galactic star-forming cores cannot be used to reproduce those observed in other galaxies, although the discrepancies arise primarily as a result of beam filling factors. The much larger regions sampled by the Herschel beams at distances of several megaparsecs contain significant amounts of cooler gas, which dominate the extragalactic CO SLEDs, in contrast to observations of Galactic star-forming regions, which are focused specifically on cores containing primarily hot molecular gas. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. 14. ELEVATED CAMERA STAND IN FOREGROUND, FIRING CONTROL BLOCKHOUSE (BLDG. ...

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

    14. ELEVATED CAMERA STAND IN FOREGROUND, FIRING CONTROL BLOCKHOUSE (BLDG. 0545) IN CENTER, AIR SUPPLY BUILDING AND PROTECTIVE BERM IN BACKGROUND. Looking north northeast from Camera Road. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  2. Joint Entropy Minimization for Learning in Nonparametric Framework

    DTIC Science & Technology

    2006-06-09

    Tibshirani, G. Sherlock , W. C. Chan, T. C. Greiner, D. D. Weisenburger, J. O. Armitage, R. Warnke, R. Levy, W. Wilson, M. R. Grever, J. C. Byrd, D. Botstein, P...Entropy Minimization for Learning in Nonparametric Framework 33 [11] D.L. Collins, A.P. Zijdenbos, J.G. Kollokian, N.J. Sled, C.J. Kabani, C.J. Holmes

  3. Space adaptation syndrome experiments (8-IML-1)

    NASA Technical Reports Server (NTRS)

    Watt, D.

    1992-01-01

    A set of seven experiments will study adaptation of the human nervous system to weightlessness. Particular emphasis will be placed on the vestibular and proprioceptive systems. The experiments are as follows: the sled/H-reflex; rotation/vestibulo-ocular reflex; the visual stimulator experiment; proprioception (relaxed) experiment; proprioception (active) experiment; proprioception (illusion) experiment; and tactile acuity.

  4. Performance Characteristics of 5 Ft Diameter Nylon and Kevlar Hemisflo Ribbon Parachutes at Dynamic Pressures up to 6000 PSF

    DTIC Science & Technology

    1978-06-01

    deceleration resulting from its a rodynamic dr g and frictional resistance with the rails then bee m augmented by water braking. The braking force...portion of the water brake was to be buried within the sled structure. Honeycomb panels were ~o be used in place of sheet metal skin over most of

  5. Analysis of problems related to slingshot shock machine high-velocity shock testing

    NASA Technical Reports Server (NTRS)

    Shipley, J. W.

    1969-01-01

    Slingshot device is capable of imparting a square-pulse acceleration greater than 20,000 g with a pulse duration of up to 1.5 milliseconds. A load is applied to the bungee cord and the sled is drawn back to desired length. When released it provides the desired velocity at impact.

  6. Locomotor adaptation and aftereffects in patients with reduced somatosensory input due to peripheral neuropathy.

    PubMed

    Bunday, Karen L; Bronstein, Adolfo M

    2009-12-01

    We studied 12 peripheral neuropathy patients (PNP) and 13 age-matched controls with the "broken escalator" paradigm to see how somatosensory loss affects gait adaptation and the release and recovery ("braking") of the forward trunk overshoot observed during this locomotor aftereffect. Trunk displacement, foot contact signals, and leg electromyograms (EMGs) were recorded while subjects walked onto a stationary sled (BEFORE trials), onto the moving sled (MOVING or adaptation trials), and again onto the stationary sled (AFTER trials). PNP were unsteady during the MOVING trials, but this progressively improved, indicating some adaptation. During the after trials, 77% of control subjects displayed a trunk overshoot aftereffect but over half of the PNP (58%) did not. The PNP without a trunk aftereffect adapted to the MOVING trials by increasing distance traveled; subsequently this was expressed as increased distance traveled during the aftereffect rather than as a trunk overshoot. This clear separation in consequent aftereffects was not seen in the normal controls suggesting that, as a result of somatosensory loss, some PNP use distinctive strategies to negotiate the moving sled, in turn resulting in a distinct aftereffects. In addition, PNP displayed earlier than normal anticipatory leg EMG activity during the first after trial. Although proprioceptive inputs are not critical for the emergence or termination of the aftereffect, somatosensory loss induces profound changes in motor adaptation and anticipation. Our study has found individual differences in adaptive motor performance, indicative that PNP adopt different feed-forward gait compensatory strategies in response to peripheral sensory loss.

  7. Premature ignition of a rocket motor.

    SciTech Connect

    Moore, Darlene Ruth

    2010-10-01

    During preparation for a rocket sled track (RST) event, there was an unexpected ignition of the zuni rocket motor (10/9/08). Three Sandia staff and a contractor were involved in the accident; the contractor was seriously injured and made full recovery. The data recorder battery energized the low energy initiator in the rocket.

  8. 50 CFR 622.53 - Bycatch reduction device (BRD) requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... in the water, or if it is shackled, tied, or otherwise connected to a sled, door, or other device... shrimp trawler. (1) Exemptions from BRD requirement—(i) Royal red shrimp exemption. A shrimp trawler is... royal red shrimp. (ii) Try net exemption. A shrimp trawler is exempt from the requirement to have...

  9. 78 FR 69363 - Lake Tahoe Basin Management Unit, California, Heavenly Mountain Resort Epic Discovery Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ... alignment. Sky Cycle Canopy Tour--Top of Gondola/Adventure Peak Area, An aerial activity known as the Sky Cycle Canopy Tour will be implemented in an area between the gondola top station and the gondola mid... allows users on individual sleds to descend on a raised track through the forest and natural...

  10. Head impact mechanisms of a child occupant seated in a child restraint system as determined by impact testing.

    PubMed

    Yoshida, Ryoichi; Okada, Hiroshi; Nomura, Mitsunori; Mizuno, Koji; Tanaka, Yoshinori; Hosokawa, Naruyuki

    2011-11-01

    In side collision accidents, the head is the most frequently injured body region for child occupants seated in a child restraint system (CRS). Accident analyses show that a child's head can move out of the CRS shell, make hard contact with the vehicle interior, and thus sustain serious injuries. In order to improve child head protection in side collisions, it is necessary to understand the injury mechanism of a child in the CRS whose head makes contact with the vehicle interior. In this research, an SUV-to-car oblique side crash test was conducted to reconstruct such head contacts. A Q3s child dummy was seated in a CRS in the rear seat of the target car. The Q3s child dummy's head moved out beyond the CRS side wing, moved laterally, and made contact with the side window glass and the doorsill. It was demonstrated that the hard head contact, which produced a high HIC value, could occur in side collisions. A series of sled tests was carried out to reproduce the dummy kinematic behavior observed in the SUV-to-car crash test, and the sled test conditions such as sled angle, ECE seat slant angle and velocity-time history that duplicated the kinematic behavior were determined. A parametric study also was conducted with the sled tests; and it was found that the impact angle, harness slack, chest clip, and the CRS side wing shape affected the torso motion and head contact with the vehicle interior.

  11. Denakenaga' for Children. Lesson Plans for Teaching Denakenaga' (Minto-Nenana Tanana) to Children in Elementary Grades.

    ERIC Educational Resources Information Center

    Thompson, Chad; Frank, Ellen

    This curriculum for elementary school-level instruction in Denakenaga' is intended for development of oral native language skills. Included are plans for 60 25-minute lessons, arranged in 11 units: basic conversation; food and eating; hunting and animals; clothing and morning routine; weather; body parts; dogs and sleds; numbers; the village;…

  12. Doggone Good Lessons.

    ERIC Educational Resources Information Center

    Raack, Lenaya

    1999-01-01

    Describes a teacher's experiences developing and implementing a three-week interdisciplinary unit for fourth grade students that revolves around the Alaskan Iditarod sled dog race. Students read about the race history, figure out a racing budget, learn about animal breeding and care, and follow the actual progress of the racing teams via Internet…

  13. Alaska Women in the Iditarod.

    ERIC Educational Resources Information Center

    Stout, Peg

    This instructional booklet features biographical stories of Alaskan women who have raced and participated in the annual Iditarod Sled Dog Race. The Iditarod race covers over 1,049 miles from Anchorage to Nome and attracts racers from all over the world. A team consists of 12 to 18 dogs and their trainer or musher. The first Iditarod took place in…

  14. Salvage and Demolition of Two Navy Offshore Platforms,

    DTIC Science & Technology

    1984-10-01

    SES-100B Trials SESTF JEFF Craft Tests AALC-ETU LACV-30 Army Coast Guard Sled USCG n Sea/Air Rescue USCG Data Buoy NORDA Voyageur Ops Army/Bell HADAPS...for Lighted Buoys Issued F. .. . . . 4 Date Event 2 Jan. 1984 Florida, Dept. of Natural Resources Approval 9 Feb. 1984 Commerce Business Daily

  15. Development and validation of a frontal impact 6-year-old occupant and wheelchair computer model.

    PubMed

    Ha, DongRan; Bertocci, Gina; Jategaonkar, Rohit

    2007-01-01

    Many children with disabilities use their wheelchair as a vehicle seat when traveling. To date, few studies have focused on pediatric wheelchair users in transit. A computer model representing a manual pediatric wheelchair seated with a Hybrid III 6-year-old anthropomorphic test device subjected to a 20-g/48-kph (30-mph) frontal crash was developed in MADYMO. The wheelchair was secured using a 4-point tiedown system, and the occupant was restrained using a 3-point belt system. The time history profiles of the computer model were tuned to those of the sled tests. The peak value for key variables was compared between the sled tests and the model. To evaluate model variable time histories, Pearson's correlation coefficients (r) between the sled test and the model outcome measures were determined. The correlation coefficients ranged from .86 to .95, with an average r of .91. This indicates that there are "high" correlations between the model and sled tests across all variables. The pediatric wheelchair model developed and validated in this study will provide a foundation for studying the response of a manual pediatric wheelchair in frontal impacts and associated injury risks for pediatric wheelchair users.

  16. Novel Robotic Tools for Piping Inspection and Repair, Phase 1

    DTIC Science & Technology

    2014-02-13

    11 Basic automated motion using software ... mockup horizontally and vertically. Gripping force testing Pulling in an axial direction the gripper assembly achieved 36.33lbs of gripping force...bags being partially inflated (Figure 11). Figure 11 - Gripper sleds Basic automated motion using software The robot successfully ran on auto

  17. Hemodiafiltration Decreases Serum Levels of Inflammatory Mediators in Severe Leptospirosis: A Prospective Study

    PubMed Central

    Cleto, Sérgio Aparecido; Rodrigues, Camila Eleutério; Malaque, Ceila Maria; Sztajnbok, Jaques; Seguro, Antônio Carlos; Andrade, Lúcia

    2016-01-01

    Background Leptospirosis is a health problem worldwide. Its most severe form is a classic model of sepsis, provoking acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI), with associated mortality that remains unacceptably high. We previously demonstrated that early initiation of sustained low-efficiency dialysis (SLED) followed by daily SLED significantly decreases mortality. However, the mode of clearance can also affect dialysis patient outcomes. Therefore, the objective of this study was to compare the effects of SLED with traditional (diffusive) clearance, via hemodialysis, and SLED with convective clearance, via hemodiafiltration (SLEDf), in patients with severe leptospirosis. Methods In this prospective study, conducted in the intensive care unit (ICU) from 2009 through 2012, we compared two groups—SLED (n = 19) and SLEDf (n = 20)—evaluating demographic, clinical, and biochemical parameters, as well as serum levels of interleukins, up to the third day after admission. All patients received dialysis early and daily thereafter. Results During the study period, 138 patients were admitted to our ICU with a diagnosis of leptospirosis; 39 (36 males/3 females) met the criteria for ARDS and AKI. All patients were on mechanical ventilation and were comparable in terms of respiratory parameters. Mortality did not differ between the SLEDf and SLED groups. However, post-admission decreases in the serum levels of interleukin (IL)-17, IL-7, and monocyte chemoattractant protein-1 were significantly greater in the SLEDf group. Direct bilirubin and the arterial oxygen tension/fraction of inspired oxygen ratio were significantly higher in the SLED group. We identified the following risk factors (sensitivities/specificities) for mortality in severe leptospirosis: age ≥ 55 years (67%/91%); serum urea ≥ 204 mg/dl (100%/70%); creatinine ≥ 5.2 mg/dl (100%/58%); Acute Physiology and Chronic Health Evaluation II score ≥ 39.5 (67%/88%); Sequential

  18. PMHS impact response in 3 m/s and 8 m/s nearside impacts with abdomen offset.

    PubMed

    Miller, Carl S; Madura, Nathaniel H; Schneider, Lawrence W; Klinich, Kathleen D; Reed, Matthew P; Rupp, Jonathan D

    2013-11-01

    Lateral impact tests were performed using seven male post-mortem human subjects (PMHS) to characterize the force-deflection response of contacted body regions, including the lower abdomen. All tests were performed using a dual-sled, side-impact test facility. A segmented impactor was mounted on a sled that was pneumatically accelerated into a second, initially stationary sled on which a subject was seated facing perpendicular to the direction of impact. Positions of impactor segments were adjusted for each subject so that forces applied to different anatomic regions, including thorax, abdomen, greater trochanter, iliac wing, and thigh, could be independently measured on each PMHS. The impactor contact surfaces were located in the same vertical plane, except that the abdomen plate was offset 5.1 cm towards the subject. The masses of the sleds and the force- deflection characteristics of the energy-absorbing interface material between the sleds were set to provide the impactor sled with a velocity profile that matched the average driver door velocity history produced in a series of side NCAP tests. Impactor padding was also selected so that average ATD pelvis and thorax responses from the same series of side NCAP tests were reproduced when the ATD used in these tests was impacted using the average door-velocity history. Each subject was first impacted on one side of the body using an initial impactor speed of 3 m/s. If a post-test CT scan and strain-gage data revealed two or fewer non-displaced rib fractures, then the PMHS was impacted on the contralateral side of the body at a speed of 8 m/s or 10 m/s. The results of tests in the 3 m/s and 8 m/s conditions were used to develop force-deflection response corridors for the abdomen, force history response corridors for the pelvis (iliac wing and greater trochanter), the midthigh, and the thorax. Response corridors for the lateral acceleration of the pelvis were also developed. Future work will compare side impact ATD

  19. Interrelationships between different loads in resisted sprints, half-squat 1 RM and kinematic variables in trained athletes.

    PubMed

    Martínez-Valencia, María Asunción; González-Ravé, José M; Santos-García, Daniel Juárez; Alcaraz Ramón, Pedro E; Navarro-Valdivielso, Fernando

    2014-01-01

    Resisted sprint running is a common training method for improving sprint-specific strength. It is well-known that an athlete's time to complete a sled-towing sprint increases linearly with increasing sled load. However, to our knowledge, the relationship between the maximum load in sled-towing sprint and the sprint time is unknown, The main purpose of this research was to analyze the relationship between the maximum load in sled-towing sprint, half-squat maximal dynamic strength and the velocity in the acceleration phase in 20-m sprint. A second aim was to compare sprint performance when athletes ran under different conditions: un-resisted and towing sleds. Twenty-one participants (17.86 ± 2.27 years; 1.77 ± 0.06 m and 69.24 ± 7.20 kg) completed a one repetition maximum test (1 RM) from a half-squat position (159.68 ± 22.61 kg) and a series of sled-towing sprints with loads of 0, 5, 10, 15, 20, 25, 30% body mass (Bm) and the maximum resisted sprint load. No significant correlation (P<0.05) was found between half-squat 1 RM and the sprint time in different loaded conditions. Conversely, significant correlations (P<0.05) were found between maximum load in resisted sprint and sprint time (20-m sprint time, r=-0.71; 5% Bm, r=-0.73; 10% Bm, r=-0.53; 15% Bm, r=-0.55; 20% Bm, r=-0.65; 25% Bm, r=-0.44; 30% Bm, r=-0.63; MaxLoad, r= 0.93). The sprinting velocity significantly decreased by 4-22% with all load increases. Stride length (SL) also decreased (17%) significantly across all resisted conditions. In addition, there were significant differences in stride frequency (SF) with loads over 15% Bm. It could be concluded that the knowledge of the individual maximal load in resisted sprint and the effects on the sprinting kinematic with different loads, could be interesting to determinate the optimal load to improve the acceleration phase at sprint running.

  20. Transonic and supersonic ground effect aerodynamics

    NASA Astrophysics Data System (ADS)

    Doig, G.

    2014-08-01

    A review of recent and historical work in the field of transonic and supersonic ground effect aerodynamics has been conducted, focussing on applied research on wings and aircraft, present and future ground transportation, projectiles, rocket sleds and other related bodies which travel in close ground proximity in the compressible regime. Methods for ground testing are described and evaluated, noting that wind tunnel testing is best performed with a symmetry model in the absence of a moving ground; sled or rail testing is ultimately preferable, though considerably more expensive. Findings are reported on shock-related ground influence on aerodynamic forces and moments in and accelerating through the transonic regime - where force reversals and the early onset of local supersonic flow is prevalent - as well as more predictable behaviours in fully supersonic to hypersonic ground effect flows.

  1. Simultaneous drag and flow measurements of Olympic skeleton athletes

    NASA Astrophysics Data System (ADS)

    Moon, Yae Eun; Digiulio, David; Peters, Steve; Wei, Timothy

    2009-11-01

    The Olympic sport of skeleton involves an athlete riding a small sled face first down a bobsled track at speeds up to 130 km/hr. In these races, the difference between gold and missing the medal stand altogether can be hundredths of a second per run. As such, reducing aerodynamic drag through proper body positioning is of first order importance. To better study the flow behavior and to improve the performance of the athletes, we constructed a static force balance system on a mock section of a bobsled track. Athlete and the sled are placed on the force balance system which is positioned at the exit of an open loop wind tunnel. Simultaneous drag force and DPIV velocity field measurements were made along with video recordings of body position to aid the athletes in determining their optimal aerodynamic body position.

  2. Analysis of ocular torsion data from Space Labs D-1 and SL-1

    NASA Technical Reports Server (NTRS)

    Oman, C. M.

    1990-01-01

    A series of preflight, inflight, and postflight vestibular experiments were conducted on Spacelab missions SL-1 and D-1. Two portions of the investigation, the 'sled' and 'dome' functional objectives, involved recording the torsional motion of human subject's eyes. In the SL-1 sled and dome experiments, preflight and postflight ocular torsion was recorded on 35 mm film using a Nikon motor driven camera (2.6 frames/sec). The film was to be analyzed by measuring the motion of contact lens landmarks using a Hermes senior film scanner. However, an inflight failure of the dome experiment camera flash unit led the crew to utilize the Spacelab video camera as an alternative contingency method for imaging the eye in this FO. A suitable method for analysis of the video data was developed. Results of the analysis are presented.

  3. A profile of women participants in five long distance winter sporting events.

    PubMed

    Mischler, J K

    1989-01-01

    Women have been entering long distance winter sports in increasing numbers in Alaska and other states and countries. Much publicity has been given to the success of some. The 1,100 mile Iditarod Sled Dog Race across Alaska has been won by a woman every year since 1985. The Minnesota Beargrease Sled Dog Marathon 500 mile race was won by a woman in 1988. But what of the experience of the average female entrant? This investigation sought to examine the circumstances of each of the women who competed in the Iditarod, Iditaski, Iditabike, Yukon Quest and Beargrease Marathon. Since December 1987, 79 questionnaires were mailed to all of the women participants (past and present) of these events and as of July 1988 the response rate was 58%. Examination of the findings in the areas of age ranges; training/competition miles; types, rates, self-treatment of injuries and protection from cold are reported.

  4. Technology evaluation of man-rated acceleration test equipment for vestibular research

    NASA Technical Reports Server (NTRS)

    Taback, I.; Kenimer, R. L.; Butterfield, A. J.

    1983-01-01

    The considerations for eliminating acceleration noise cues in horizontal, linear, cyclic-motion sleds intended for both ground and shuttle-flight applications are addressed. the principal concerns are the acceleration transients associated with change in direction-of-motion for the carriage. The study presents a design limit for acceleration cues or transients based upon published measurements for thresholds of human perception to linear cyclic motion. The sources and levels for motion transients are presented based upon measurements obtained from existing sled systems. The approaches to a noise-free system recommends the use of air bearings for the carriage support and moving-coil linear induction motors operating at low frequency as the drive system. Metal belts running on air bearing pulleys provide an alternate approach to the driving system. The appendix presents a discussion of alternate testing techniques intended to provide preliminary type data by means of pendulums, linear motion devices and commercial air bearing tables.

  5. A new look at deep-sea video

    USGS Publications Warehouse

    Chezar, H.; Lee, J.

    1985-01-01

    A deep-towed photographic system with completely self-contained recording instrumentation and power can obtain color-video and still-photographic transects along rough terrane without need for a long electrically conducting cable. Both the video- and still-camera systems utilize relatively inexpensive and proven off-the-shelf hardware adapted for deep-water environments. The small instrument frame makes the towed sled an ideal photographic tool for use on ship or small-boat operations. The system includes a temperature probe and altimeter that relay data acoustically from the sled to the surface ship. This relay enables the operator to monitor simultaneously water temperature and the precise height off the bottom. ?? 1985.

  6. Gastritis and Gastric Ulcers in Working Dogs

    PubMed Central

    Davis, Michael S.; Williamson, Katherine K.

    2016-01-01

    Gastritis and gastric ulcers are an important cause of morbidity and mortality in canine athletes. Although the majority of scientific work on this condition has been performed in ultraendurance racing sled dogs, this condition has been identified in other canine athletes, including sled dogs competing in shorter events and dogs performing off-leash explosive detection duties. The cause of the syndrome is unknown, but current hypotheses propose a link between exercise-induced hyperthermia and loss of gastric mucosal barrier function as an early event in the pathogenesis. Treatment is focused on prevention of clinical disease using acid secretion inhibitors, such as omeprazole, which has excellent efficacy in controlled clinical studies. PMID:27092307

  7. Development and validation of rear impact computer simulation model of an adult manual transit wheelchair with a seated occupant.

    PubMed

    Salipur, Zdravko; Bertocci, Gina

    2010-01-01

    It has been shown that ANSI WC19 transit wheelchairs that are crashworthy in frontal impact exhibit catastrophic failures in rear impact and may not be able to provide stable seating support and thus occupant protection for the wheelchair occupant. Thus far only limited sled test and computer simulation data have been available to study rear impact wheelchair safety. Computer modeling can be used as an economic and comprehensive tool to gain critical knowledge regarding wheelchair integrity and occupant safety. This study describes the development and validation of a computer model simulating an adult wheelchair-seated occupant subjected to a rear impact event. The model was developed in MADYMO and validated rigorously using the results of three similar sled tests conducted to specifications provided in the draft ISO/TC 173 standard. Outcomes from the model can provide critical wheelchair loading information to wheelchair and tiedown manufacturers, resulting in safer wheelchair designs for rear impact conditions.

  8. The effect of resisted sprint training on maximum sprint kinetics and kinematics in youth.

    PubMed

    Rumpf, Michael C; Cronin, John B; Mohamad, Ikhwan N; Mohamad, Sharil; Oliver, Jon L; Hughes, Michael G

    2015-01-01

    Resisted sled towing is a popular and efficient training method to improve sprint performance in adults, however, has not been utilised in youth populations. The purpose therefore was to investigate the effect of resisted sled towing training on the kinematics and kinetics of maximal sprint velocity in youth of different maturation status. Pre- and post-intervention 30 metre sprint performance of 32 children, 18 pre-peak height velocity (PHV) and 14 mid-/post-PHV, were tested on a non-motorised treadmill. The 6-week intervention consisted of ∼12 sessions for pre-PHV and 14 for mid-/post-PHV of resisted sled towing training with each sessions comprised of 8-10 sprints covering 15-30 metres with a load of 2.5, 5, 7.5 or 10% body mass. Pre-PHV participants did not improve sprint performance, while the mid-/post-PHV participants had significant (P < 0.05) reductions (percent change, effect size) in sprint time (-5.76, -0.74), relative leg stiffness (-45.0, -2.16) and relative vertical stiffness (-17.4, -0.76) and a significant increase in average velocity (5.99, 0.76), average step rate (5.65, 0.53), average power (6.36, 0.31), peak horizontal force (9.70, 0.72), average relative vertical forces (3.45, 1.70) and vertical displacement (14.6, 1.46). It seems that sled towing may be a more suitable training method in mid-/post-PHV athletes to improve 30 metre sprint performance.

  9. 30. "CONSTRUCTION PHASING, STATION '50' AREA." Specifications No. ENG043535775, Drawing ...

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

    30. "CONSTRUCTION PHASING, STATION '50' AREA." Specifications No. ENG-04-353-57-75, Drawing No. AF-4502-19, sheet 4 of 5, D.O. Series No. AF 1439/26. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 5296, Date: 10 NOV. 59. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  10. NASA satellite to track North Pole expedition

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The proposed expedition of a lone explorer and the use of Nimbus 6 (NASA meteorological research satellite) to track his journey is reported. The journey is scheduled to start March 4, 1978, and will cover a distance of 6.000 Km (3,728 miles) from northern Canada to the North Pole and return, traveling the length of Greenland's isolated interior. The mode of transportation for the explorer will be by dog sled. Instrumentation and tracking techniques are discussed.

  11. The development of a flight termination parachute system for a 1900 lb payload

    SciTech Connect

    Waye, D.E.

    1997-04-01

    A 30-ft-diameter ringslot/solid parachute was designed, developed, and tested at Sandia National Laboratories as the major component of a flight termination system required for a 1900-lb gliding delivery platform. Four full-scale sled tests were performed to validate the design models of the parachute, determine reefing line length, demonstrate structural adequacy of the parachute materials, and demonstrate that performance met the design requirements.

  12. Evaluation of Head and Brain Injury Risk Functions using Sub-Injurious Human Volunteer Data.

    PubMed

    Sanchez, Erin J; Gabler, Lee F; McGhee, James S; Olszko, Ardyn V; Chancey, Valeta Carol; Crandall, Jeff; Panzer, Matthew B

    2017-03-30

    Risk assessment models are developed to estimate the probability of brain injury during head impact using mechanical response variables such as head kinematics and brain tissue deformation. Existing injury risk functions have been developed using different datasets based on human volunteer and scaled animal injury responses to impact. However, many of these functions have not been independently evaluated with respect to laboratory-controlled human response data. In this study, the specificity of fourteen existing brain injury risk functions was assessed by evaluating their ability to correctly predict non-injurious response using previously conducted sled tests with well-instrumented human research volunteers. Six degree-of-freedom head kinematics data were obtained for 335 sled tests involving subjects in frontal, lateral, and oblique sled conditions up to 16 Gs peak sled acceleration. A review of the medical reports associated with each individual test indicated no clinical diagnosis of mild or moderate brain injury in any of the cases evaluated. Kinematic-based head and brain injury risk probabilities were calculated directly from the kinematic data, while strain-based risks were determined through finite element model simulation of the 335 tests. Several injury risk functions sub¬stanti¬ally over pre¬dict the likelihood of concussion and diffuse axonal injury; proposed maximum principal strain (MPS)-based injury risk functions predicted nearly 80 concussions and 14 cases of severe diffuse axonal injury out of the 335 non-injurious cases. This work is an important first step in assessing the efficacy of existing brain risk functions and highlights the need for more predictive injury assessment models.

  13. A Crashworthy Armored Pilot Seat for Helicopters

    DTIC Science & Technology

    1974-01-18

    Configuration 14 III Resoons, of F/A &Mmbars 17 IV Summay of Drop Tests 29 V Summary of Horizontal Sled Test 32 VI AcmY Armored E/A Cram=n Swot , Test Results...and 3. !st Conditions: 3 hours of vibration, resonance search, dwell and cycling in each of three (3) axes, 5 to 500 Hz maxi - mum of +2.5 g. ;sults: No

  14. EERE's State & Local Energy Data Tool

    ScienceCinema

    Shambarger, Erick; DeCesaro, Jennifer

    2016-07-12

    EERE's State and Local Energy Data (SLED) Tool provides basic energy market information that can help state and local governments plan and implement clean energy projects, including electricity generation; fuel sources and costs; applicable policies, regulations, and financial incentives; and renewable energy resource potential. Watch this video to learn more about the tool and hear testimonials from real users about the benefits of using this tool.

  15. Learning Data Driven Representations from Large Collections of Multidimensional Patterns with Minimal Supervision

    DTIC Science & Technology

    2008-08-04

    Tibshirani, G. Sherlock , W. C. Chan, T. C. Greiner, D. D. Weisenburger, J. O. Armitage, R. Warnke, R. Levy, W. Wilson, M. R. Grever, J. C. Byrd, D...Imaging, pages 263–274, 1995. [Collins et al., 1998] D.L. Collins, A.P. Zijdenbos, J.G. Kollokian, N.J. Sled, C.J. Kabani, C.J. Holmes , and A.C. Evans

  16. History of the Army Ground Forces. Study Number 24. History of the Mountain Training Center

    DTIC Science & Technology

    1948-01-01

    the new Northland ski model hasd been so changed by specifications set up in the Office of Quaa’termaster General that it was practically useless, and...gaiters back on the list, an inferior model copared with the previous yeaa; ani the ski cap was radically altered to a most unserviceable design. Theae...snowshoes. (2) Relative value of toboggans versus sleds. (3) Mechanized transportation versus pack animls . The ski-versus-snowshoe test was cancelled by

  17. Redesign of Medical Stretcher for Special Operation Pararescue Jumpers

    DTIC Science & Technology

    2014-06-30

    acceptabiltiy and ease of use. 15. SUBJECT TERMS Medical Stretcher, Special operations stretcher, Litter , Special Operations Equipment 16...rescuer may carry the injured person or load them into a stretcher/sled/ litter --whichever can get them to safety the fastest. Sometimes, the injured... litter could also serve as a sensor platform to feed real-time medical stats to the rescuer. Currently the two main “stretchers” used by the PJs are

  18. Locomotor Adaptation and Aftereffects in Patients With Reduced Somatosensory Input Due to Peripheral Neuropathy

    PubMed Central

    Bunday, Karen L.

    2009-01-01

    We studied 12 peripheral neuropathy patients (PNP) and 13 age-matched controls with the “broken escalator” paradigm to see how somatosensory loss affects gait adaptation and the release and recovery (“braking”) of the forward trunk overshoot observed during this locomotor aftereffect. Trunk displacement, foot contact signals, and leg electromyograms (EMGs) were recorded while subjects walked onto a stationary sled (BEFORE trials), onto the moving sled (MOVING or adaptation trials), and again onto the stationary sled (AFTER trials). PNP were unsteady during the MOVING trials, but this progressively improved, indicating some adaptation. During the after trials, 77% of control subjects displayed a trunk overshoot aftereffect but over half of the PNP (58%) did not. The PNP without a trunk aftereffect adapted to the MOVING trials by increasing distance traveled; subsequently this was expressed as increased distance traveled during the aftereffect rather than as a trunk overshoot. This clear separation in consequent aftereffects was not seen in the normal controls suggesting that, as a result of somatosensory loss, some PNP use distinctive strategies to negotiate the moving sled, in turn resulting in a distinct aftereffects. In addition, PNP displayed earlier than normal anticipatory leg EMG activity during the first after trial. Although proprioceptive inputs are not critical for the emergence or termination of the aftereffect, somatosensory loss induces profound changes in motor adaptation and anticipation. Our study has found individual differences in adaptive motor performance, indicative that PNP adopt different feed-forward gait compensatory strategies in response to peripheral sensory loss. PMID:19741105

  19. Mobility and Economic Feasibility of the Greenland Inland Traverse (GrIT)

    DTIC Science & Technology

    2011-03-01

    towing four GrIT08 bladder sleds at NEEM . ........................................... 29 Figure 15. John Deere 8530 tractor equipped with Soucy tracks...19 Table 2. LC130 parameters for flights from Kanger to NEEM and Summit. ...................................... 36 Table 3. Summary...initiated a 705-mile (1410-mile round trip) over-snow traverse, de- parting from Thule Air Base, to re-supply the international drilling camp at NEEM and

  20. Effects of Frequency and Motion Paradigm on Perception of Tilt and Translation During Periodic Linear Acceleration

    NASA Technical Reports Server (NTRS)

    Beaton, K. H.; Holly, J. E.; Clement, G. R.; Wood, Scott J.

    2009-01-01

    Previous studies have demonstrated an effect of frequency on the gain of tilt and translation perception. Results from different motion paradigms are often combined to extend the stimulus frequency range. For example, Off-Vertical Axis Rotation (OVAR) and Variable Radius Centrifugation (VRC) are useful to test low frequencies of linear acceleration at amplitudes that would require impractical sled lengths. The purpose of this study was to compare roll-tilt and lateral translation motion perception in 12 healthy subjects across four paradigms: OVAR, VRC, sled translation and rotation about an earth-horizontal axis. Subjects were oscillated in darkness at six frequencies from 0.01875 to 0.6 Hz (peak acceleration equivalent to 10 deg, less for sled motion below 0.15 Hz). Subjects verbally described the amplitude of perceived tilt and translation, and used a joystick to indicate the direction of motion. Consistent with previous reports, tilt perception gain decreased as a function of stimulus frequency in the motion paradigms without concordant canal tilt cues (OVAR, VRC and Sled). Translation perception gain was negligible at low stimulus frequencies and increased at higher frequencies. There were no significant differences between the phase of tilt and translation, nor did the phase significantly vary across stimulus frequency. There were differences in perception gain across the different paradigms. Paradigms that included actual tilt stimuli had the larger tilt gains, and paradigms that included actual translation stimuli had larger translation gains. In addition, the frequency at which there was a crossover of tilt and translation gains appeared to vary across motion paradigm between 0.15 and 0.3 Hz. Since the linear acceleration in the head lateral plane was equivalent across paradigms, differences in gain may be attributable to the presence of linear accelerations in orthogonal directions and/or cognitive aspects based on the expected motion paths.

  1. Restoring Eelgrass (Zostera marina) from Seed: A Comparison of Planting Methods for Large-Scale Projects

    DTIC Science & Technology

    2008-03-01

    A. V. Lombana, K. A. Moore, J. M. Rhode, and H. E. Woods. 2000. A review of issues in seagrass seed dormancy and germination : Implications for...temperatures and salinity. Seed plant- ing occurred in September 2005, prior to the initiation of seed germination in the late fall (Orth and Moore... germination was complete) by sieving the sediment and retrieving all Figure 6. Pumping seeds to the deployed planting sled. 4 ERDC/TN SAV-08-1 March 2008

  2. 28. "CONSTRUCTION PHASING, STATION '0' AREA." Specifications No. OC15775, Drawing ...

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

    28. "CONSTRUCTION PHASING, STATION '0' AREA." Specifications No. OC1-57-75, Drawing No. AF-45-02-19, sheet 3 of 5, D.O. Series No. AF 1439/25, Rev. B. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 5296 Rev. B, Date: 11/13/59. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  3. LIDAR Studies of Small-Scale Lateral Dispersion in the Ocean

    DTIC Science & Technology

    2010-09-30

    field test / pilot cruise performed in August, 2010 in the Sargasso Sea , southeast of Cape Hatteras (Fig 1). Cruise participants included the WHOI and...absorption/attenuation sensor, a Sea Sciences Acrobat tow sled, and a new micro CTD and fluorometer sampling package for small-scale surveys of the dye...density fronts (Fig. 1). The sites for these releases were chosen on the basis of satellite images of sea surface height and temperature and model results

  4. LIDAR and Numerical Modeling Studies of Small-Scale Lateral Dispersion in the Ocean

    DTIC Science & Technology

    2010-09-30

    in the Sargasso Sea , southeast of Cape Hatteras (Fig 1). Cruise participants included the WHOI and UMass dye PIs, the OSU dye group (Levine), and the...This includes a SATLANTIC Apparent Optical Properties System, a WetLabs ACs spectral absorption/attenuation sensor, a Sea Sciences Acrobat tow sled...Hatteras Figure 1. Sea Surface Temperature map of study region SW of Cape Hatteras, NC. Arrow and box show approximate location of August 2010 pilot

  5. New Tools for Ocean Exploration, Equipping the NOAA Ship Okeanos Explorer

    DTIC Science & Technology

    2008-09-01

    installed. A traction winch and approximately 8,000 meters of 0.68” umbilical cable were installed below decks in a converted tank space. A hangar...the vessel by a standard armored umbilical . The sled is then connected to the ROV, Fig 6, via a flexible, neutrally buoyant tether. The primary...Bringing Offshore Industry Advances and Experience to the Oceanographic Community,” Proceedings of Oceans 2007, MTS/IEEE, Vancouver, Canada, October 2007.

  6. 25. "GAFFTC 19 OCT 60, BLAST EFFECTS ON AIRFOILS, STATIC ...

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

    25. "G-AFFTC 19 OCT 60, BLAST EFFECTS ON AIRFOILS, STATIC RUN 5." View of track rail mounting and the water brake trough at 20,000-foot track. Looking northeast. File no. 12,358-60. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  7. Beach Nourishment Project Response and Design Evaluation: Ocean City, Maryland

    DTIC Science & Technology

    1993-08-01

    monitoring fill behavior and their relative positions to the shoreface-attached shoals .......... .. 39 Figure 18. Photograph of the sled used in nearshore...understanding the behavior of beach nourishment projects, and the objectives of this report are to document the project from its inception to the present and to...accumulation on the shoal has been irregular, with an overall average rate of 39,000 cuI yd/year. This irregular behavior ma\\ indicate an approach to

  8. Installation Restoration Program Records Search for Holloman Air Force Base, New Mexico

    DTIC Science & Technology

    1983-08-01

    34Ji.n: National Technical Information Service 5285 Port Royal Road Springfield, Virginia 22161 Federal Government agencies and their contractors...Defense. Copies of this report may be purchased from: National Technical Information Service 5285 Port Royal Road Springfield, Virginia 22161 Federal...Lagoon Disposal Site 38 19 Golf Course Landfill 37 38 Test Sled Maintenance Area 37 28 Former North Area Washrack Site 36 15 Refrigeration/Heat Shop

  9. EERE's State & Local Energy Data Tool

    SciTech Connect

    Shambarger, Erick; DeCesaro, Jennifer

    2014-06-23

    EERE's State and Local Energy Data (SLED) Tool provides basic energy market information that can help state and local governments plan and implement clean energy projects, including electricity generation; fuel sources and costs; applicable policies, regulations, and financial incentives; and renewable energy resource potential. Watch this video to learn more about the tool and hear testimonials from real users about the benefits of using this tool.

  10. 3D Finite Element Modeling of Sliding Wear

    DTIC Science & Technology

    2013-12-01

    observed in a micrograph of the recovered slipper. This methodology assumes that one can correlate the number of asperities per unit of area on the...thickness along its length (Figure IV-17) correlate to the three sled system acceleration stages. The higher the slipper acceleration the greater...can conclude that the greater the speed the greater the strain rate contribution. However, higher speeds typically correlate with higher skin

  11. Bearing Capacity of Floating Ice Sheets under Short-Term Loads: Over-Sea-Ice Traverse from McMurdo Station to Marble Point

    DTIC Science & Technology

    2015-01-01

    41,000 lb Caterpillar Challenger 95E tractor with attached Fassi crane towing a single 3000 gal. steel tank sled full of fuel (32,370 lb). Wide...load configuration approaching a lead during the 2013 MPT would be a Caterpillar Challenger 95E tractor with an attached Fassi crane (41,400 lb...for that condition. The analyses considered a Caterpillar Challenger 95E tractor with attached Fassi crane (41,000 lb combined weight) towing a

  12. In-Situ Ultrasonic Characterization of Patterns of Sediment Surface Roughness and Subsurface Volume Inhomogeneities

    DTIC Science & Technology

    2016-06-07

    was successfully converted to ocean-going use . An aluminum pressure housing (sled-type) was created containing the ultrasound machine, VCR, battery ...successfully images surface and sub-surface biogenic structure non-invasively in the laboratory (ultrasound) and convert the technology for use in...pressure housing for it waterproof to 50 m water depth. We will deploy the unit in the field with the use of divers during the summer in the

  13. Design and characterization of a mixed-signal PCB for digital-to-analog conversion in a modular and scalable infrared scene projector

    NASA Astrophysics Data System (ADS)

    Benedict, Jacob

    Infra-red (IR) sensors have proven instrumental in a wide variety of fields from military to industrial applications. The proliferation of IR sensors has spawned an intense push for technologies that can test and calibrate the multitudes of IR sensors. One such technology, IR scene projection (IRSP), provides an inexpensive and safe method for the testing of IR sensor devices. Previous efforts have been conducted to develop IRSPs based on super-lattice light emitting diodes (SLEDS). A single-color 512x512 SLEDs system has been developed, produced, and tested as documented in Corey Lange's Master's thesis, and a GOMAC paper by Rodney McGee [1][2]. Current efforts are being undergone to develop a two-color 512x512 SLEDs system designated (TCSA). The following thesis discusses the design and implementation of a custom printed circuit board (PCB), known as the FMC 4DAC, that contains both analog and digital signals. Utilizing two 16-bit digital-to-analog converters (DAC) the purpose of the board is to provide four analog current output channels for driving the TCSA system to a maximum frame rate of 1 kHz. In addition, the board supports a scalable TCSA system architecture. Several copies of the board can be run in parallel to achieve a range of analog channels between 4 and 32.

  14. Deviations from Newton's law in supersymmetric large extra dimensions

    NASA Astrophysics Data System (ADS)

    Callin, P.; Burgess, C. P.

    2006-09-01

    Deviations from Newton's inverse-squared law at the micron length scale are smoking-gun signals for models containing supersymmetric large extra dimensions (SLEDs), which have been proposed as approaches for resolving the cosmological constant problem. Just like their non-supersymmetric counterparts, SLED models predict gravity to deviate from the inverse-square law because of the advent of new dimensions at sub-millimeter scales. However SLED models differ from their non-supersymmetric counterparts in three important ways: (i) the size of the extra dimensions is fixed by the observed value of the dark energy density, making it impossible to shorten the range over which new deviations from Newton's law must be seen; (ii) supersymmetry predicts there to be more fields in the extra dimensions than just gravity, implying different types of couplings to matter and the possibility of repulsive as well as attractive interactions; and (iii) the same mechanism which is purported to keep the cosmological constant naturally small also keeps the extra-dimensional moduli effectively massless, leading to deviations from general relativity in the far infrared of the scalar-tensor form. We here explore the deviations from Newton's law which are predicted over micron distances, and show the ways in which they differ and resemble those in the non-supersymmetric case.

  15. Attention modulates adaptive motor learning in the 'broken escalator' paradigm.

    PubMed

    Patel, Mitesh; Kaski, Diego; Bronstein, Adolfo M

    2014-07-01

    The physical stumble caused by stepping onto a stationary (broken) escalator represents a locomotor aftereffect (LAE) that attests to a process of adaptive motor learning. Whether such learning is primarily explicit (requiring attention resources) or implicit (independent of attention) is unknown. To address this question, we diverted attention in the adaptation (MOVING) and aftereffect (AFTER) phases of the LAE by loading these phases with a secondary cognitive task (sequential naming of a vegetable, fruit and a colour). Thirty-six healthy adults were randomly assigned to 3 equally sized groups. They performed 5 trials stepping onto a stationary sled (BEFORE), 5 with the sled moving (MOVING) and 5 with the sled stationary again (AFTER). A 'Dual-Task-MOVING (DTM)' group performed the dual-task in the MOVING phase and the 'Dual-Task-AFTEREFFECT (DTAE)' group in the AFTER phase. The 'control' group performed no dual task. We recorded trunk displacement, gait velocity and gastrocnemius muscle EMG of the left (leading) leg. The DTM, but not the DTAE group, had larger trunk displacement during the MOVING phase, and a smaller trunk displacement aftereffect compared with controls. Gait velocity was unaffected by the secondary cognitive task in either group. Thus, adaptive locomotor learning involves explicit learning, whereas the expression of the aftereffect is automatic (implicit). During rehabilitation, patients should be actively encouraged to maintain maximal attention when learning new or challenging locomotor tasks.

  16. Case study of training, fitness, and nourishment of a dog driver during the Iditarod 1049-mile dogsled race.

    PubMed

    Cox, Carla; Gaskill, Steven; Ruby, Brent; Uhlig, Sharon

    2003-09-01

    The purpose of the present case study was threefold: (a) to estimate intake and expenditure of a dog driver (musher) while participating in the Iditarod, (b) to determine the hydration status of the musher at the completion of the event, and (c) to evaluate training related changes in aerobic capacity and body composition of a long-distance dog sled driver in preparation for and following completion of a 1049-mile (1692-km) sled dog race. Actual energy intake during the Iditarod Sled Dog Race was estimated at 8,921 kilojoules (kJ) per day. Nutrient intake expressed as percentage kJ of total energy (14%, 44% and 42% for protein, carbohydrates, and fat, respectively). Weight loss of .72 kg of body weight indicated an energy deficit of 1819 kJ per day during the race. Total energy needs per day were calculated to be 10,740 kJ/day. An increase in hematocrit and hemoglobin during the race may indicate dehydration during the event. There was an improvement in aerobic fitness during on-snow training as determined by ventilatory threshold and VO2peak data. Fat-free mass was maintained during training (46.4 kg), with a concomitant decrease in fat (2.4 kg). Fat-free mass was also maintained during the 12-day race.

  17. The nutritional requirements of exercising dogs.

    PubMed

    Hill, R C

    1998-12-01

    The nutrient requirements of canine athletes are unique. Dogs have a greater capacity for fat oxidation than humans both at rest and during exercise. In dogs undertaking endurance exercise, such as sled dogs, high fat (>50% of energy) diets increase stamina and maximize energy production, and high protein (>30% of energy) diets prevent training-induced anemia. Nutrient requirements differ, however, for sprint racing dogs, such as greyhounds. Greyhounds run faster when fed moderately increased dietary fat but run more slowly when dietary protein is increased. Sled dogs have similar energy requirements to other breeds at rest in a thermoneutral environment ( approximately 550W0.75 kJ/d where W is body weight in kg) but may require as much as 4200W0.75 kJ/d during a race. The energy requirement of greyhounds in training, however, is only approximately 600W0.75 kJ/d. There is little information, however, concerning the vitamin, mineral or other nutrient requirements of athletic dogs; most sled dogs and greyhounds are fed "homemade" recipes. These recipes usually include raw meat and represent a health risk. More studies are required to improve the health and performance of working and racing dogs.

  18. A Investigation of Gouge Initiation in High-Velocity Sliding Contact

    NASA Astrophysics Data System (ADS)

    Tachau, Robert David Mazur

    1991-02-01

    Surface damage has been observed on the rails of rocket sled tracks and on the barrels of high-velocity guns. The phenomenon is generally referred to as "gouging". Damage to a stationary surface (guider) is created from the oblique impact of a high-velocity object (slider) moving over its surface. The surface damage (gouge) is typically a shallow crater in the shape of a teardrop with the leading edge characterized by the wider end and a slightly raised lip. For rocket sleds, rail gouging occurs when the sled velocity is greater than 1.5 km/sec; while in guns, barrel gouging occurs when the velocity exceeds 4 km/sec. A model is developed to describe the phenomenon of gouging. An unbalanced slider randomly causes a shallow -angle, oblique impact between the slider and the guider. At sufficiently high velocity, the impact produces a thin, but very hot, layer of soft material at the contact surface. Under the action of a moving load, the soft layer lends itself to an antisymmetric deformation and a gouge is formed when this soft material is over-run by the slider. The model is simulated numerically with a hydrodynamic (CTH) code. The results of the simulations are in good agreement with the observed phenomena. Based on the simulated temperature and pressure profiles at the contact surface, design criteria for gouge mitigation are developed in this study.

  19. Therapeutic effectiveness of sustained low-efficiency hemodialysis plus hemoperfusion and continuous hemofiltration plus hemoperfusion for acute severe organophosphate poisoning.

    PubMed

    Hu, Shou-liang; Wang, Dan; Jiang, Hong; Lei, Qing-feng; Zhu, Xiao-hua; Cheng, Jun-zhang

    2014-02-01

    There is no report on the effects of sustained low-efficiency dialysis (SLED) plus hemoperfusion (HP) (SLED + HP) in patients with acute severe organophosphate (OP) poisoning (ASOPP). This study was designed to compare the therapeutic effectiveness between SLED + HP and continuous hemofiltration (CHF) plus HP (CHF + HP) in patients with ASOPP. In order to assess the two treatment methods, 56 patients with ASOPP were divided into CHF + HP group and SLED + HP group. The biochemical indicators, in-hospital duration, hemodynamic parameters, Acute Physiology, and Chronic Health Evaluation (APACHE II) score, and survival and mortality rates were compared. In both groups after treatment, the levels of serum creatine kinase isozyme MB, creatine kinase, creatinine, glutamic-oxalacetic transaminease, and glutamate-pyruvate transaminase, and the APACHE II scores on the first, second, and seventh day decreased (P < 0.05), whereas the levels of serum acetylcholinesterase increased. The two groups showed no statistical differences in in-hospital duration, biochemical indicators, APACHE II score, hemodynamic parameters, survival rate, or the mortality rate (P > 0.05). In conclusion, SLED has similar hemodynamic stability to CHF and the two treatment methods have similar effects on ASOPP patients. More importantly, SLED plus HP is relatively economical and convenient for patients with ASOPP in clinical practice.

  20. Immiscible experiments on the Rayleigh-Taylor instability using simultaneous particle image velocimetry and planar laser induced fluorescence concentration measurements

    NASA Astrophysics Data System (ADS)

    Mokler, Matthew; Jacobs, Jeffrey

    2014-11-01

    Incompressible Rayleigh-Taylor instability experiments are presented in which two stratified liquids having Atwood number of 0.2 are accelerated in a vertical linear induction motor driven drop tower. A test sled having only vertical freedom of motion contains the experiment tank and visualization equipment. The sled is positioned at the top of the tower within the linear induction motors and accelerated downward causing the initially stable interface to be unstable and allowing the Rayleigh-Taylor instability to develop. Forced and unforced experiments are conducted using an immiscible liquid combination. Forced initial perturbations are produced by vertically oscillating the test sled prior to the start of acceleration. The interface is visualized using a 445 nm laser light source that illuminates a fluorescent dye mixed in one of the fluids and aluminum oxide particles dispersed in both fluids. The laser beam is synchronously swept across the fluorescent fluid, at the frame rate of the camera, exposing a single plane of the interface. The resulting images are recorded using a monochromatic high speed video camera. Time dependent velocity and density fields are obtained from the recorded images allowing for 2D full field measurements of turbulent kinetic energy and turbulent mass transport.

  1. Is there a low-back cost to hip-centric exercise? Quantifying the lumbar spine joint compression and shear forces during movements used to overload the hips.

    PubMed

    Frost, David M; Beach, Tyson; Fenwick, Chad; Callaghan, Jack; McGill, Stuart

    2012-05-01

    The aim of this study was to quantify joint compression and shear forces at L4/L5 during exercises used to overload the hips. Nine men performed 36 "walking" trials using two modalities: (1) sled towing and (2) exercise bands placed around the ankles. Participants completed forward, backward, and lateral trials with bent and straight legs at three separate loads. Surface electromyography (EMG) was recorded bilaterally from eight torso and thigh sites, upper body and lumbar spine motion were quantified, and hand forces were measured. An EMG-driven musculoskeletal model was used to estimate the muscular contribution to joint compression and shear. Peak reaction, muscle and joint compression and shear forces, and peak gluteus medius and maximus activity were calculated. Significant differences were noted in each dependent measure; however, they were dependent on direction of travel, leg position, and load. The highest joint compression and shear forces for the sled and band conditions were 4378 N and 626 N, and 3306 N and 713 N, respectively. In general, increasing the band tension had little effect on all dependent measures, although a load-response was found during the sled conditions. Before using any exercise to improve hip function, the potential benefits should be weighed against "costs" to neighbouring joints.

  2. Laboratory Reconstructions of Real World Frontal Crash Configurations using the Hybrid III and THOR Dummies and PMHS.

    PubMed

    Petitjean, Audrey; Lebarbe, Matthieu; Potier, Pascal; Trosseille, Xavier; Lassau, Jean-Pierre

    2002-11-01

    Load-limiting belt restraints have been present in French cars since 1995. An accident study showed the greater effectiveness in thorax injury prevention using a 4 kN load limiter belt with an airbag than using a 6 kN load limiter belt without airbag. The criteria for thoracic tolerance used in regulatory testing is the sternal deflection for all restraint types, belt and/or airbag restraint. This criterion does not assess the effectiveness of the restraint 4 kN load limiter belt with airbag observed in accidentology. To improve the understanding of thoracic tolerance, frontal sled crashes were performed using the Hybrid III and THOR dummies and PMHS. The sled configuration and the deceleration law correspond to those observed in the accident study. Restraint conditions evaluated are the 6 kN load-limiting belt and the 4 kN load-limiting belt with an airbag. Loads between the occupant and the sled environment were recorded. Various measurements (including thoracic deflections and head, thorax and pelvis accelerations and angular velocities on the dummies) characterize the dummy and PMHS behavior. PMHS anthropometry and injuries were noted. This study presents the test methodology and the results used to evaluate dummy ability to discriminate both restraint types and dummy measurement ability to be representative of thoracic injury risk for all restraint types. The injury results of the PMHS tests showed the same tendency as the accident study. Some of the criteria proposed in the literature did not show a better protection of the 4 kN load limiter belt with airbag restraint, in particular thoracic deflection maxima for both dummies. The four thoracic deflections measured on the THOR and Hybrid III dummies may allow more accurate analysis of the loading pattern and therefore of injury risk.

  3. Occupant kinematics and shoulder belt retention in far-side lateral and oblique collisions: a parametric study.

    PubMed

    Forman, Jason L; Lopez-Valdes, Francisco; Lessley, David J; Riley, Patrick; Sochor, Mark; Heltzel, Sara; Ash, Joseph; Perz, Rafal; Kent, Richard W; Seacrist, Thomas; Arbogast, Kristy B; Tanji, Hiromasa; Higuchi, Kazuo

    2013-11-01

    In far-side impacts, head contact with interior components is a key injury mechanism. Restraint characteristics have a pronounced influence on head motion and injury risk. This study performed a parametric examination of restraint, positioning, and collision factors affecting shoulder belt retention and occupant kinematics in far-side lateral and oblique sled tests with post mortem human subjects (PMHS). Seven PMHS were subjected to repeated tests varying the D-ring position, arm position, pelvis restraint, pre-tensioning, and impact severity. Each PMHS was subjected to four low-severity tests (6.6 g sled acceleration pulse) in which the restraint or position parameters were varied and then a single higher-severity test (14 g) with a chosen restraint configuration (total of 36 tests). Three PMHS were tested in a purely lateral (90° from frontal) impact direction; 4 were tested in an oblique impact (60° from frontal). All subjects were restrained by a 3-point seatbelt. Occupant motion was tracked with a 3D optoelectric high speed motion capture system. For all restraint configurations, the 60° oblique impact angle was associated with greater lateral head excursion than the 90° impact angle. This unexpected result reflects the increased axial rotation of the torso in the oblique impacts, which allowed the shoulder to displace more relative to the shoulder belt and thus the head to displace more relative to the sled buck. Restraint engagement of the torso and shoulder was actually greater in the purely lateral impacts than in the oblique impacts. Pretensioning significantly reduced lateral head excursion (175 mm average in the low-severity tests across all restraint configurations).

  4. Upper neck forces and moments and cranial angular accelerations in lateral impact.

    PubMed

    Yoganandan, Narayan; Pintar, Frank A; Zhang, Jiangyue; Stemper, Brian D; Philippens, Mat

    2008-03-01

    Biomechanical studies using postmortem human subjects (PMHS) in lateral impact have focused primarily on chest and pelvis injuries, mechanisms, tolerances, and comparison with side impact dummies. A paucity of data exists on the head-neck junction, i.e., forces and moments, and cranial angular accelerations. The objective of this study was to determine lateral impact-induced three-dimensional temporal forces and moments at the head-neck junction and cranial linear and angular accelerations from sled tests using PMHS and compare with responses obtained from an anthropomorphic test device (dummy) designed for lateral impact. Following initial evaluations, PMHS were seated on a sled, restrained using belts, and lateral acceleration was applied. Specimens were instrumented with a pyramid-shaped nine-accelerometer package to record cranial accelerations. A sled accelerometer was used to record the input acceleration. Radiographs and computed tomography scans were obtained to identify pathology. A similar testing protocol was adopted for dummy tests. Results indicated that profiles of forces and moments at the head-neck junction and cranial accelerations were similar between the two models. However, peak forces and moments at the head-neck junction were lower in the dummy than PMHS. Peak cranial linear and angular accelerations were also lower in the dummy than in the PMHS. Fractures to the head-neck complex were not identified in PMHS tests. Peak cranial angular accelerations were suggestive of mild traumatic brain injury with potential for loss of consciousness. Findings from this study with a limited dataset are valuable in establishing response corridors for side impacts and evaluating side impact dummies used in crashworthiness and safety-engineering studies.

  5. Biomechanical and Injury Response to Posterolateral Loading from Torso Side Airbags

    PubMed Central

    Hallman, Jason J.; Yoganandan, Narayan; Pintar, Frank A.

    2013-01-01

    This study characterized thoracoabdominal response to posterolateral loading from a seat-mounted side airbag. Seven unembalmed post-mortem human subjects were exposed to ten airbag deployments. Subjects were positioned such that the deploying airbag first contacted the posterolateral thorax between T6 and L1 while stationary (n = 3 × 2 aspects) or while subjected to left lateral sled impact at ΔV = 6.7 m/s (n = 4). Chestband contours were analyzed to quantify deformation direction in the thoracic x–y plane (zero degrees indicating anterior and 180° indicating posterior), magnitude, rate, and viscous response. Skeletal injuries were consistent with posterolateral contact; visceral injuries consisted of renal (n = 1) or splenic (n = 3) lacerations. Deformation direction was transient during sled impact, progressing from 122 ± 5° at deformation onset to 90° following maximum deflection. Angles from stationary subjects progressed from 141 ± 9° to 120°. Peak normalized deflections, peak rates, and VCmax ranges were 0.075 – 0.171, 3.7 – 12.7 m/s, and 0.3 – 0.6 m/s with stationary airbag, respectively; ranges were 0.167 – 0.297, 7.4 – 18.3 m/s, and 0.7 – 3.0 m/s with airbag sled impact, respectively. Peak deflections were measured at angles between 99° – 135° and 98° – 125° for stationary and dynamic conditions, respectively. Because of deflection angle transience and localized injury response, both posterolateral and lateral injury metrics may be required for this boundary condition. Contrasted with flat rigid or anterolateral loading, biomechanical response to side airbag interaction may be augmented by peak normalized deflection or VCmax at 130°. PMID:21512911

  6. Abdominal Twin Pressure Sensors for the assessment of abdominal injuries in Q dummies: in-dummy evaluation and performance in accident reconstructions.

    PubMed

    Beillas, Philippe; Alonzo, François; Chevalier, Marie-Christine; Lesire, Philippe; Leopold, Franck; Trosseille, Xavier; Johannsen, Heiko

    2012-10-01

    The Abdominal Pressure Twin Sensors (APTS) for Q3 and Q6 dummies are composed of soft polyurethane bladders filled with fluid and equipped with pressure sensors. Implanted within the abdominal insert of child dummies, they can be used to detect abdominal loading due to the belt during frontal collisions. In the present study - which is part of the EC funded CASPER project - two versions of APTS (V1 and V2) were evaluated in abdominal belt compression tests, torso flexion test (V1 only) and two series of sled tests with degraded restraint conditions. The results suggest that the two versions have similar responses, and that the pressure sensitivity to torso flexion is limited. The APTS ability to detect abdominal loading in sled tests was also confirmed, with peak pressures typically below 1 bar when the belt loaded only the pelvis and the thorax (appropriate restraint) and values above that level when the abdomen was loaded directly (inappropriate restraint). Then, accident reconstructions performed as part of CASPER and previous EC funded projects were reanalyzed. Selected data from 19 dummies (12 Q6 and 7 Q3) were used to plot injury risk curves. Maximum pressure, maximum pressure rate and their product were all found to be injury predictors. Maximum pressure levels for a 50% risk of AIS3+ were consistent with the levels separating appropriate and inappropriate restraint in the sled tests (e.g. 50% risk of AIS3+ at 1.09 bar for pressure filtered CFC180). Further work is needed to refine the scaling techniques between ages and confirm the risk curves.

  7. Autonomous Underwater Vehicle(AUV) and Towed Vehicle Technologies for Under-Ice Hydrothermal Vent Studies at the Gakkel Ridge

    NASA Astrophysics Data System (ADS)

    Singh, H.; Akin, D.; Reves-Sohn, R.; Humphris, S.; Shank, T.; Edmonds, H.

    2006-12-01

    The extreme polar environment presents a unique challenge to the use of the otherwise mature oceanographic technologies associated with Autonomous Underwater Vehicles (AUVs), Remotely Operated Vehicles (ROVs) and towed vehicles. For deep water mapping and sampling applications, ice cover in the arctic is a formidable obstacle. In pursuing our goals to locate, map and sample hydrothermal vents on the Gakkel Ridge, we have built and plan to deploy two AUVs named JAGUAR and PUMA and a towed sampling sled with hydraulically actuated sampling chambers. Our methodologies for working with AUVs in the Arctic differ significantly from standard blue-water operations. Specifically, we have focused on, deploying and calibrating acoustic transponders with the limited mobility imposed by multi-year ice; a far more robust system architecture for dealing with component failures underwater; an autonomous manipulation system on the AUV for capturing sessile biological organisms and geological samples; and a low bandwidth acoustic tether for vehicle status, navigation and mission redirection. Our sampling sled was designed with the premise that the limited mobility associated with working in ice will at best provide us with a few, short opportunities to image and sample on a hydrothermal vent site. To this end our sled is equipped with a suite of imaging and chemical sensors as well as devices for quickly obtaining multiple samples of both sessile and motile biological organisms. We plan to deploy these new technologies during the International Polar Year in 2007 as part of a collaborative international effort to characterize the biological and geological characteristics of hydrothermal venting on the ultra-slow spreading Gakkel Ridge in the eastern Arctic basin.

  8. Interaction between acoustic startle and habituated neck postural responses in seated subjects.

    PubMed

    Blouin, Jean-Sébastien; Siegmund, Gunter P; Timothy Inglis, J

    2007-04-01

    Postural and startle responses rapidly habituate with repeated exposures to the same stimulus, and the first exposure to a seated forward acceleration elicits a startle response in the neck muscles. Our goal was to examine how the acoustic startle response is integrated with the habituated neck postural response elicited by forward accelerations of seated subjects. In experiment 1, 14 subjects underwent 11 sequential forward accelerations followed by 5 additional sled accelerations combined with a startling tone (124-dB sound pressure level) initiated 18 ms after sled acceleration onset. During the acceleration-only trials, changes consistent with habituation occurred in the root-mean-square amplitude of the neck muscles and in the peak amplitude of five head and torso kinematic variables. The subsequent addition of the startling tone restored the amplitude of the neck muscles and four of the five kinematic variables but shortened onset of muscle activity by 9-12 ms. These shortened onset times were further explored in experiment 2, wherein 16 subjects underwent 11 acceleration-only trials followed by 15 combined acceleration-tone trials with interstimulus delays of 0, 13, 18, 23, and 28 ms. Onset times shortened further for the 0- and 13-ms delays but did not lengthen for the 23- and 28-ms delays. These temporal and spatial changes in EMG can be explained by a summation of the excitatory drive converging at or before the neck muscle motoneurons. The present observations suggest that habituation to repeated sled accelerations involves extinguishing the startle response and tuning the postural response to the whole body disturbance.

  9. Oblique lateral impact biofidelity deflection corridors from Post Mortem Human Surrogates.

    PubMed

    Yoganandan, Narayan; Humm, John R; Arun, Mike W J W J; Pintar, Frank A

    2013-11-01

    The objective of the study was to determine the thorax and abdomen deflection-time corridors in oblique side impacts. Data were analyzed from Post Mortem Human Surrogate (PMHS) sled tests, certain aspects of which were previously published. A modular and scalable anthropometry-specific segmented load-wall system was fixed to the platform of the sled. Region-specific forces were recorded from load cells attached to the load-wall plates. The thorax and abdomen regions were instrumented with chestbands, and deflection contours were obtained. Biomechanical responses were processed using the impulse-momentum normalization method and scaled to the mid-size male mass, 76-kg. The individual effective masses of the thorax and abdomen were used to determine the scale factors in each sled test, thus using the response from each experiment. The maximum deflections and their times of attainments were obtained, and mean and plus minus one standard deviation corridors were derived. Test-by-test thorax and abdomen force-time histories are given. Deflection-time histories for each specimen for the two body regions and corridors are presented. The mean maximum deflections for the thorax and abdomen body regions were 68.41 ± 16.1 and 68.98 ± 12.69 mm, respectively. Deflections were greater in oblique than pure lateral loading tests for both body regions, indicating the increased sensitivity of oblique side impact vector to the human response. The mean and one standard deviation responses of the thorax and abdomen serve as biofidelity corridors under oblique loading. Because modern instrumentation techniques can accommodate deflection sensors in the thorax and abdomen in devices such as WorldSID, and computer finite element models are flexible enough to extract regional and local deformation fields, the present data can be used to evaluate dummy biofidelity and validate and verify numerical models. They can be used to advance injury assessment reference values in oblique impacts.

  10. MOLECULAR AND ATOMIC LINE SURVEYS OF GALAXIES. I. THE DENSE, STAR-FORMING GAS PHASE AS A BEACON

    SciTech Connect

    Geach, James E.; Papadopoulos, Padelis P. E-mail: padelis@mpifr-bonn.mpg.de

    2012-10-01

    We predict the space density of molecular gas reservoirs in the universe and place a lower limit on the number counts of carbon monoxide (CO), hydrogen cyanide (HCN) molecular, and [C II] atomic emission lines in blind redshift surveys in the submillimeter-centimeter spectral regime. Our model uses (1) recently available HCN spectral line energy distributions (SLEDs) of local luminous infrared galaxies (LIRGs, L{sub IR} > 10{sup 11} L{sub Sun }), (2) a value for {epsilon}{sub *} = SFR/M{sub dense}(H{sub 2}) provided by new developments in the study of star formation feedback on the interstellar medium, and (3) a model for the evolution of the infrared luminosity density. Minimal 'emergent' CO SLEDs from the dense gas reservoirs expected in all star-forming systems in the universe are then computed from the HCN SLEDs since warm, HCN-bright gas will necessarily be CO-bright, with the dense star-forming gas phase setting an obvious minimum to the total molecular gas mass of any star-forming galaxy. We include [C II] as the most important of the far-infrared cooling lines. Optimal blind surveys with the Atacama Large Millimeter Array (ALMA) could potentially detect very distant (z {approx} 10-12) [C II] emitters in the {>=}ULIRG galaxy class at a rate of {approx}0.1-1 hr{sup -1} (although this prediction is strongly dependent on the star formation and enrichment history at this early epoch), whereas the (high-frequency) Square Kilometer Array will be capable of blindly detecting z > 3 low-J CO emitters at a rate of {approx}40-70 hr{sup -1}. The [C II] line holds special promise for detecting metal-poor systems with extensive reservoirs of CO-dark molecular gas where detection rates with ALMA can reach up to 2-7 hr{sup -1} in Bands 4-6.

  11. HERUS: A CO Atlas from SPIRE Spectroscopy of Local ULIRGs

    NASA Astrophysics Data System (ADS)

    Pearson, Chris; Rigopoulou, Dimitra; Hurley, Peter; Farrah, Duncan; Afonso, Jose; Bernard-Salas, Jeronimo; Borys, Colin; Clements, David L.; Cormier, Diane; Efstathiou, Andreas; Gonzalez-Alfonso, Eduardo; Lebouteiller, Vianney; Spoon, Henrik

    2016-11-01

    We present the Herschel SPIRE Fourier Transform Spectroscopy (FTS) atlas for a complete flux-limited sample of local ultraluminous infrared galaxies (ULIRGs) as part of the HERschel Ultra Luminous InfraRed Galaxy Survey (HERUS). The data reduction is described in detail and was optimized for faint FTS sources ,with particular care being taken for the subtraction of the background, which dominates the continuum shape of the spectra. To improve the final spectra, special treatment in the data reduction has been given to any observation suffering from artifacts in the data caused by anomalous instrumental effects. Complete spectra are shown covering 200-671 μm, with photometry in the SPIRE bands at 250, 350, and 500 μm. The spectra include near complete CO ladders for over half of our sample, as well as fine structure lines from [C i] 370 μm, [C i] 609 μm, and [N ii] 205 μm. We also detect H2O lines in several objects. We construct CO spectral line energy distributions (SLEDs) for the sample, and compare their slopes with the far-infrared (FIR) colors and luminosities. We show that the CO SLEDs of ULIRGs can be broadly grouped into three classes based on their excitation. We find that the mid-J (5 < J < 8) lines are better correlated with the total FIR luminosity, suggesting that the warm gas component is closely linked to recent star formation. The higher J transitions do not linearly correlate with the FIR luminosity, consistent with them originating in hotter, denser gas that is unconnected to the current star formation. We conclude that in most cases more than one temperature component is required to model the CO SLEDs.

  12. Assessment of the pubic force as a pelvic injury criterion in side impact.

    PubMed

    Leport, Tiphaine; Baudrit, Pascal; Trosseille, Xavier; Petit, Philippe; Palisson, Anna; Vallancien, Guy

    2007-10-01

    In the literature, injuries at the ischio or ilio pubic ramus level are reported to occur to approximately (3/4) of the occupants injured at the pelvis during side impact. Assuming that the load going through the pubis was a good indicator of the ramus stress, the pubic force was widely accepted as a protection criterion for pelvic fractures on side impact dummies. However, no data regarding the actual loads going through the pubis is currently available in the literature for Post Mortem Human Subjects (PMHS) in dynamic conditions. The goal of this study was to determine pelvic biofidelity specifications in terms of load path, to evaluate the pertinence of the pubic force as a criterion, and to develop a pelvic injury risk curve as a function of the pubic force. For that purpose, a pubic load cell was developed for PMHS use, and 16 side impact tests were performed on 8 PMHS using boundary conditions similar to impactor tests and sled tests reported in the literature. One kind of impact was applied on one side of a subject and the other kind of impact was then applied on the other side of the same subject, at non injury severities. The ratio between the peak external force and the peak pubic force was calculated for each subject, and a mean ratio was then calculated for each of the test conditions. These ratios were finally used to calculate the pubic forces from the external pelvic forces for 90 PMHS side impact test data available in the literature. Injury risk curves as a function of the pubic force were developed from these data. Two normalized pubic force corridors from the 16 tests are presented, the first one for the impactor tests, the second one for the sled-like tests. The test results show statistically different ratios between the peak external force and the peak pubic force, for the two configurations (an average ratio of 3.3 for impactor tests and 4.6 for sled-like tests). The PMHS injury risk curves based on the external pelvic force were observed to

  13. An Rf-gun-driven recirculated linac as injector and FEL driver.

    SciTech Connect

    Andersson, A.; Biedron, S.; Eriksson, M.; Freund, H.; Werin, S.

    1999-08-23

    A new pre-injector for the MAX-Laboratory is under design and construction. A thermionic rf gun, designed to operate at medium currents with low back bombardment power, is under construction. The gun will, via a magnetic compressor and energy filter, feed a recirculated linac consisting of two SLED-equipped structures giving 125 MeV each. The first will be delivered in 1999. The system is aimed as a pre-injector for the existing storage rings at MAX-Lab, but will also open up possibilities for a SASE FEL in the UV reaching above 100 MW below 100 run.

  14. The effect of obesity on the restraint of automobile occupants.

    PubMed

    Forman, Jason; Lopez-Valdes, Francisco J; Lessley, David; Kindig, Matthew; Kent, Richard; Bostrom, Ola

    2009-10-01

    As obesity rates increase, the protection of obese occupants will become increasingly important in vehicle and restraint design. As a first step in this effort, this study seeks to compare the kinematics, dynamics, and injuries of obese post mortem human surrogates (PMHS) to (approximately) 50(th) percentile adult male PMHS in frontal impact sled tests with a force-limiting, pre-tensioning restraint system. Forty-eight km/h, frontal impact sled tests were performed with a sled buck representing the rear seat occupant compartment of a 2004 mid-sized sedan. The restraint system consisted of a 3-point belt with a pretensioner and a progressive force-limiter at the retractor. The test subjects were either obese PMHS or approximately 50(th) percentile adult male PMHS. Instrumentation included accelerometer packages on the spine. Deformation of the subjects' chests were measured using chestbands placed nominally at the superior-inferior locations of the 4(th) and 8(th) ribs. Tension in the restraint system was measured at the upper shoulder belt, lower shoulder belt, and the lap belt. Motion of the head, shoulder, pelvis, and knee were recorded using high-speed video. Two obese PMHS (average mass 137 kg, average stature 186 cm) and three approximately mid-sized male PMHS (average mass 68 kg, average stature 176 cm) were tested. The obese PMHS exhibited significantly greater forward motion of the head and the pelvis compared to the mid-sized PMHS. The obese PMHS also exhibited backwards torso rotation at the time of maximum forward excursion, whereas the mid-sized PMHS did not. The obese PMHS exhibited average maximum chest compressions of approximately 44% (+/- 9% standard deviation) of their initial chest depths, and exhibited 26 g (+/- 2 g) average 3 ms clip maximum chest resultant acceleration. In comparison, the mid-sized PMHS exhibited averages of 29% (+/- 9%) maximum chest compression and 35 g (+/- 4 g) maximum 3 ms clip chest acceleration. The obese PMHS exhibited

  15. 29. "TEST TRACK, STATION '0' THROUGH '200' AREA." Specifications No. ...

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

    29. "TEST TRACK, STATION '0' THROUGH '200' AREA." Specifications No. ENG-OC-1-57-75, Drawing No. AF-6009-15, sheet 53 of 96, D.O. Series No. AF 1394/73, Rev. C. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 5296 Rev. C, Date: 19 NOV 59. Drawing includes plan, section, and details of track. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  16. The Inductrack concept: A new approach to magnetic levitation

    SciTech Connect

    Post, R.F.; Ryutov, D.

    1996-05-01

    This report describes theoretical and experimental investigations of a new approach to the problem of the magnetic levitation of a moving object. By contrast with previously studied levitation approaches, the Inductrack concept concept represents a simpler, potentially less expensive, and totally passive means of levitating a high-speed train. It may also be applicable to other areas where simpler magnetic levitation systems are needed, for example, high-speed test sleds for crash testing applications, or low-friction conveyer systems for industrial use.

  17. Easily constructed, economical seawater intake and supply system

    USGS Publications Warehouse

    Bouck, G.R.

    1981-01-01

    A water intake system was designed and installed in Admiralty Inlet, Puget Sound, Washington. The dual system consisted of polyvinylchloride (PVC) pipes, a concrete pit and pumps located on shore at zero tide; and cables attached laterally to the pipelines and terminally between a shoreward anchor and to a seaward intake sled held in place with an 1800 kg Dansforth anchor. The overall construction costs were much lower than those for concrete-lined ductile iron pipe. Nearly three years after its construction, this system has withstood tides and storms without apparent adverse effect. Its application to lakes or rivers is equally possible.

  18. Performance Evaluation of Velocity Measurement Systems

    DTIC Science & Technology

    1975-04-01

    cosu (t - t-) for 0 < t • t^ < n/u, and 0 for t - t- > TT/W then for a properly selected value of Ui the output e will be 9 •> em ( 1 + costo (t...tower systems and on the CERF sled track for ystems. Dynamic transducer inputs were (over) DD,^N RM 7J 1473 EDITION OF 1 NOV 45 IS OBSOLETE...UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE fl^.n Dmtm Enternd) u^-;c.—, .. . .^ -i^^Mi^ —^ _ 1 a m 1 uwm ii Itttd ASSIFIFn MtCUWITY

  19. A Survey of Biodynamic Test Devices and Methods,

    DTIC Science & Technology

    1984-04-01

    failure. Animal tests are especially valuable in suggesting injury mechanisms that can occur under specified occupant-vehicle configurations. Comparison...Frequency RanCe 27000iz e.4, Number 1 e.4.a, on sled 21/2q e.4.b. on subject/dumrly f. Other Parameters Monitoreo : LUNG PRESSURE. BELT FORCES I IJ I...4.a. on ile_ _ _ v.4.u. un s.uject/ourvy I. Other Parameters Monitoreo : 40 NATO/AGARD Impact Test Facility Survey ID #33 1. Name and Address of

  20. The Effect of Obesity on the Restraint of Automobile Occupants

    PubMed Central

    Forman, Jason; Lopez-Valdes, Francisco J.; Lessley, David; Kindig, Matthew; Kent, Richard; Bostrom, Ola

    2009-01-01

    As obesity rates increase, the protection of obese occupants will become increasingly important in vehicle and restraint design. As a first step in this effort, this study seeks to compare the kinematics, dynamics, and injuries of obese post mortem human surrogates (PMHS) to (approximately) 50th percentile adult male PMHS in frontal impact sled tests with a force-limiting, pre-tensioning restraint system. Forty-eight km/h, frontal impact sled tests were performed with a sled buck representing the rear seat occupant compartment of a 2004 mid-sized sedan. The restraint system consisted of a 3-point belt with a pretensioner and a progressive force-limiter at the retractor. The test subjects were either obese PMHS or approximately 50th percentile adult male PMHS. Instrumentation included accelerometer packages on the spine. Deformation of the subjects' chests were measured using chestbands placed nominally at the superior-inferior locations of the 4th and 8th ribs. Tension in the restraint system was measured at the upper shoulder belt, lower shoulder belt, and the lap belt. Motion of the head, shoulder, pelvis, and knee were recorded using high-speed video. Two obese PMHS (average mass 137 kg, average stature 186 cm) and three approximately mid-sized male PMHS (average mass 68 kg, average stature 176 cm) were tested. The obese PMHS exhibited significantly greater forward motion of the head and the pelvis compared to the mid-sized PMHS. The obese PMHS also exhibited backwards torso rotation at the time of maximum forward excursion, whereas the mid-sized PMHS did not. The obese PMHS exhibited average maximum chest compressions of approximately 44% (± 9% standard deviation) of their initial chest depths, and exhibited 26 g (± 2 g) average 3 ms clip maximum chest resultant acceleration. In comparison, the mid-sized PMHS exhibited averages of 29% (± 9%) maximum chest compression and 35 g (± 4 g) maximum 3 ms clip chest acceleration. The obese PMHS exhibited 7 and 2 rib

  1. Future ESA missions in biology.

    PubMed

    Bonting, S L

    1984-01-01

    A survey is given of the life sciences research program sponsored by the European Space Agency (ESA). This program rests on a number of facilities originated by ESA: Spacelab, Space sled, Biorack, Anthrorack, Eureca and its Botany - and Protein Crystallization facilities. They are all to be brought into space and returned by one of the NASA Space Shuttles. With these facilities a wide range of space biology research will be covered: cell biology, developmental biology, botany, human physiology, radiobiology, exobiology and biotechnology. Information is given on how to prepare, submit and execute an experiment proposal.

  2. A family of fiber-optic based pressure sensors for intracochlear measurements

    NASA Astrophysics Data System (ADS)

    Olson, Elizabeth S.; Nakajima, Hideko H.

    2015-02-01

    Fiber-optic pressure sensors have been developed for measurements of intracochlear pressure. The present family of transducers includes an 81 μm diameter sensor employing a SLED light source and single-mode optic fiber, and LED/multi-mode sensors with 126 and 202 μm diameter. The 126 μm diameter pressure sensor also has been constructed with an electrode adhered to its side, for coincident pressure and voltage measurements. These sensors have been used for quantifying cochlear mechanical impedances, informing our understanding of conductive hearing loss and its remediation, and probing the operation of the cochlear amplifier.

  3. Radio-Frequency Pulse Compression for Linear Accelerators.

    NASA Astrophysics Data System (ADS)

    Nantista, Christopher Dennis

    Recent efforts to develop plans for an electron -positron linear collider with center-of-mass energy approaching a TeV have highlighted the need for sources capable of delivering hundreds of megawatts of peak rf drive power at X-band frequencies. This need has driven work in the area of rf pulse compression, which enhances the peak power available from pulsed rf tubes by compressing their output pulses in time, accumulating the available energy into shorter pulses. The classic means of rf pulse compression for linear accelerators is SLED. This technique is described, and the problem it presents for multibunch acceleration explained. Other pulse compression schemes, capable of producing suitable output pulses are explored, both theoretically and experimentally, in particular Binary Pulse Compression and SLED-II. The merits of each are considered with regard to gain, efficiency, complexity, size and cost. The development of some novel system components, along with the theory behind their design, is also discussed. The need to minimize copper losses in long waveguide runs led to the use of the circular TE_{01} propagation mode in over-moded guide, requiring much attention to mechanisms of coupling power between modes. The construction and commissioning of complete, high-power pulse compression systems is reported on, as well as their use in the testing of X-band accelerating structures, which, along with the X-band klystrons used, were developed at SLAC in parallel with the pulse compression work. The focus of the dissertation is on SLED-II, the favored scheme in some current linear accelerator designs. In addition to our experimental results, practical implementation considerations and design improvements are presented. The work to date has led to detailed plans for SLED-II systems to be used in the Next Linear Collider Test Accelerator, now under construction at SLAC. The prototype of the upgraded system is near completion. Descriptions of various rf pulse

  4. Accelerator and rf system development for NLC

    SciTech Connect

    Vlieks, A.E.; Callin, R.; Deruyter, H.

    1993-04-01

    An experimental station for an X-band Next Linear Collider has been constructed at SLAC. This station consists of a klystron and modulator, a low-loss waveguide system for rf power distribution, a SLED II pulse-compression and peak-power multiplication system, acceleration sections and beam-line components (gun, prebuncher, preaccelerator, focussing elements and spectrometer). An extensive program of experiments to evaluate the performance of all components is underway. The station is described in detail in this paper, and results to date are presented.

  5. Dispersion development program. [development of a fin stabilized submissile and ejection system for the Little John warhead

    NASA Technical Reports Server (NTRS)

    Carlson, D. J.; Lusardi, R. J.; Phillips, W. H.

    1975-01-01

    The requirement for the predictable dispersion of small munitions over large areas from ground support missile systems has resulted in the development of a fin stabilized submissile and sling ejection system for the Little John warhead. The progressive development of this system is traced including a comparison of simulator, sled test, and flight test results. The results indicate that it is not only necessary but also possible to eject long slender bodies, from a missile warhead at Mach 1, in a stable, uniform and predictable manner.

  6. Future ESA Missions in Biology

    NASA Astrophysics Data System (ADS)

    Bonting, Sjoerd L.

    1984-12-01

    A survey is given of the life sciences research program sponsored by the European Space Agency (ESA). This program rests on a number of facilities originated by ESA: Spacelab, Space sled, Biorack, Anthrorack, Eureca and its Botany — and Protein Crystallization facilities. They are all to be brough into space and returned by one of the NASA Space Shuttles. With these facilities a wide range of space biology research will be covered: cell biology, developmental biology, botany, human physiology, radio-biology, exobiology and biotechnology. Information is given on how to prepare, submit and execute an experiment proposal.

  7. Autonomous Sea-Ice Thickness Survey

    DTIC Science & Technology

    2016-06-01

    to tow an electromagnetic induction meter over sea ice in McMurdo Sound , Antarctica. This proof-of-concept survey aimed to demonstrate improved...Documentation Page ERDC/CRREL SR-16-4 iv Figures and Tables Figures 1 The runway and roads on McMurdo Sound sea ice in November 2009. (Map data...4 4 The EM31 in the sled towed by Yeti along Pegasus Cut-Off Road on McMurdo Sound sea ice. The blue box housed the battery

  8. 27. "SITE PLAN." Specifications No. OC15775, Drawing No. AF600915, sheet ...

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

    27. "SITE PLAN." Specifications No. OC1-57-75, Drawing No. AF-60-09-15, sheet 1 of 96, D.O. Series No. AF 1394/20, Rev. B. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract no. 5296 Rev. B, Date: 11/17/59. Site plan of 20,000-foot track, including construction phasing notes. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  9. View looks south southeast at North Base, from a point ...

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

    View looks south southeast at North Base, from a point near the rocket sled test track. From left to right, the most prominent buildings on the skyline are Building 4505 with its ancillary buildings; Building 4500, Control Tower; followed by Buildings 4402 (Hangar No. 2), 4401 (Hangar No. 1), and 4305 (Unicon Portable Hangar) with their respective ancillary structures. The large structure in the distance at the far right of the view is the Test Support Facility at South Base. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  10. Determination of the availability of appropriate aged flight rocket motors. [captive tests to determine case bond separation and grain bore cracking

    NASA Technical Reports Server (NTRS)

    Martin, P. J.

    1974-01-01

    A program to identify surplus solid rocket propellant engines which would be available for a program of functional integrity testing was conducted. The engines are classified as: (1) upper stage and apogee engines, (2) sounding rocket and launch vehicle engines, and (3) jato, sled, and tactical engines. Nearly all the engines were available because their age exceeds the warranted shelf life. The preference for testing included tests at nominal flight conditions, at design limits, and to establish margin limits. The principal failure modes of interest were case bond separation and grain bore cracking. Data concerning the identification and characteristics of each engine are tabulated. Methods for conducting the tests are described.

  11. Polymer infiltration studies

    NASA Technical Reports Server (NTRS)

    Marchello, Joseph M.

    1994-01-01

    During the past three months, significant progress has been made on the preparation of carbon fiber composites using advanced polymer resins. The results are set forth in recent reports and publications, and will be presented at forthcoming national and international meetings. Current and ongoing research activities reported herein include: textile composites from powder-coated towpreg - role of surface coating in braiding; prepregger hot sled operation in making tape from powder coated tow; ribbonizing powder-impregnated towpreg; textile composites from powder-coated towpreg - role of bulk factor in consolidation; powder curtain prepreg process improvements in doctoring of powder; and hot/cold shoe for ATP open-section part warpage control.

  12. Development of a technique for inflight jet noise simulation. I, II

    NASA Technical Reports Server (NTRS)

    Clapper, W. S.; Stringas, E. J.; Mani, R.; Banerian, G.

    1976-01-01

    Several possible noise simulation techniques were evaluated, including closed circuit wind tunnels, free jets, rocket sleds and high speed trains. The free jet technique was selected for demonstration and verification. The first paper describes the selection and development of the technique and presents results for simulation and in-flight tests of the Learjet, F106, and Bertin Aerotrain. The second presents a theoretical study relating the two sets of noise signatures. It is concluded that the free jet simulation technique provides a satisfactory assessment of in-flight noise.

  13. ER Consolidated Qtrly Rpt_July-September 2015_January 2016

    SciTech Connect

    Cochran, John R.

    2016-01-01

    This Environmental Restoration Operations (ER) Consolidated Quarterly Report (ER Quarterly Report) provides the status of ongoing corrective action activities being implemented by Sandia National Laboratories, New Mexico (SNL/NM) for the July, August, and September 2015 quarterly reporting period. The Solid Waste Management Units (SWMUs) and Areas of Concern (AOCs) identified for corrective action at SNL/NM are listed in Table I-1. The work completed during this quarter is reported below in Sections I.2.1 and I.2.2. Section I.2.1 summarizes the quarterly activities at sites undergoing corrective action field activities (SWMUs 8 and 58, 68, 149, 154, and 502, and three groundwater AOCs). Section I.2.2 summarizes quarterly activities at sites where the New Mexico Environment Department (NMED) has issued a certificate of completion and the site is in the corrective action complete (CAC) regulatory process. Currently, the Mixed Waste Landfill (MWL, SWMU 76) is the only site in the CAC regulatory process. Corrective action activities have been deferred at the Long Sled Track (SWMU 83), the Gun Facilities (SWMU 84), and the Short Sled Track (SWMU 240) because these are active mission facilities.

  14. Rear seat occupant safety: kinematics and injury of PMHS restrained by a standard 3-point belt in frontal crashes.

    PubMed

    Michaelson, Jarett; Forman, Jason; Kent, Richard; Kuppa, Shashi

    2008-11-01

    Very little experimental research has focused on the kinematics, dynamics, and injuries of rear-seated occupants. This study seeks to develop a baseline response for rear-seated post mortem human surrogates (PMHS) in frontal crashes. Three PMHS sled tests were performed in a sled buck designed to represent the interior rear-seat compartment of a contemporary mid-sized sedan. All occupants were positioned in the right-rear passenger seat and subjected to simulated frontal crashes with an impact speed of 48 km/h. The subjects were restrained by a standard, rear seat, 3-point seat belt. The response of each subject was evaluated in terms of whole-body kinematics, dynamics, and injury. All the PMHS experienced excessive forward translation of the pelvis resulting in a backward rotation of the torso at the time of maximum forward excursion. The three subjects experienced maximum normalized chest deflections of 30%, 45%, and 30%, respectively, and maximum 3 ms clip resultant chest accelerations of 50, 42, and 52 g, respectively. Additionally, each PMHS received at least 13 rib fractures (maximum of 29 fractures), and flexion-tension induced neck injuries initiating in the lower cervical spine (C4-T1). The neck trauma ranged from ligament damage (AIS 1) to complete cervical spine transection (AIS 5).

  15. Evaluation of Chest Injury Mechanisms in Nearside Oblique Frontal Impacts

    PubMed Central

    Iraeus, Johan; Lindquist, Mats; Wistrand, Sofie; Sibgård, Elin; Pipkorn, Bengt

    2013-01-01

    Despite the use of seat belts and modern safety systems, many automobile occupants are still seriously injured or killed in car crashes. Common configurations in these crashes are oblique and small overlap frontal impacts that often lead to chest injuries. To evaluate the injury mechanism in these oblique impacts, an investigation was carried out using mathematical human body model simulations. A model of a simplified vehicle interior was developed and validated by means of mechanical sled tests with the Hybrid III dummy. The interior model was then combined with the human body model THUMS and validated by means of mechanical PMHS sled tests. Occupant kinematics as well as rib fracture patterns were predicted with reasonable accuracy. The final model was updated to conform to modern cars and a simulation matrix was run. In this matrix the boundary conditions, ΔV and PDOF, were varied and rib fracture risk as a function of the boundary conditions was evaluated using a statistical framework. In oblique frontal impacts, two injury producing mechanisms were found; (i) diagonal belt load and (ii) side structure impact. The second injury mechanism was found for PDOFs of 25°–35°, depending on ΔV. This means that for larger PDOFs, less ΔV is needed to cause a serious chest injury. PMID:24406957

  16. Upper and Lower Neck Loads in Belted Human Surrogates in Frontal Impacts

    PubMed Central

    Yoganandan, Narayan; Pintar, Frank A.; Moore, Jason; Rinaldi, James; Schlick, Michael; Maiman, Dennis J.

    2012-01-01

    The upper and lower neck loads in the restrained Hybrid III dummy and Test Device for Human Occupant Restraint (THOR) were computed in simulated frontal impact sled tests at low, medium, and high velocities; repeatability performance of the two dummies were evaluated at all energy inputs; peak forces and moments were compared with computed loads at the occipital condyles and cervical-thoracic junctions from tests using post mortem human surrogates (PMHS). A custom sled buck was used to position the surrogates. Repeated tests were conducted at each velocity for each dummy and sufficient time was allowed to elapse between the two experiments. The upper and lower neck forces and moments were determined from load cell measures and its locations with respect to the ends of the neck. Both dummies showed good repeatability for axial and shear forces and bending moments at all changes in velocity inputs. Morphological characteristics in the neck loading responses were similar in all surrogates, although the peak magnitudes of the variables differed. In general, the THOR better mimicked the PMHS response than the Hybrid III dummy, and factors such as neck design and chest compliance were attributed to the observed variations. While both dummies were not designed for use at the two extremes of the tested velocities, results from the present study indicate that, currently the THOR may be the preferred anthropomorphic testing device in crashworthiness research studies and full-scale vehicle tests at all velocities. PMID:23169123

  17. Biomechanical responses of PMHS in moderate-speed rear impacts and development of response targets for evaluating the internal and external biofidelity of ATDS.

    PubMed

    Kang, Yun-Seok; Bolte, John H; Moorhouse, Kevin; Donnelly, Bruce; Herriott, Rodney; Mallory, Ann

    2012-10-01

    The objectives of this study were to obtain biomechanical responses of post mortem human subjects (PMHS) by subjecting them to two moderate-speed rear impact sled test conditions (8.5g, 17 km/h; 10.5g, 24 km/h) while positioned in an experimental seat system, and to create biomechanical targets for internal and external biofidelity evaluation of rear impact ATDs. The experimental seat was designed to measure external loads on the head restraint (4 load cells), seat back (6 load cells), and seat pan (4 load cells) such that subject dynamic interaction with the seat could be evaluated. This seat system was capable of simulating the dynamic characteristics of modern vehicle seat backs by considering the moment-rotation properties of a typical passenger vehicle, thus providing a more realistic test environment than using a rigid seat with a non-rotating seat back as done in previous studies. Instrumentation used to measure biomechanical responses of the PMHS included both accelerometers and angular rate sensors (ARS). A total of fourteen sled tests using eight PMHS (males 175.8 ± 6.2 cm of stature and 78.4 ± 7.2 kg of weight) provided data sets of seven PMHS for both test conditions. The biomechanical responses are described at both speeds, and cervical spine injuries are documented. Biomechanical targets are also created for internal and external biofidelity evaluation of rear impact anthropomorphic test devices (ATDs).

  18. Spatial and temporal variation in the abundance, distribution and population structure of epibenthic megafauna in Port Foster, Deception Island

    NASA Astrophysics Data System (ADS)

    Cranmer, T. L.; Ruhl, H. A.; Baldwin, R. J.; Kaufmann, R. S.

    2003-06-01

    Abundance and spatial distribution of epibenthic megafauna were examined at Port Foster, Deception Island, five times between March 1999 and November 2000. Camera sled surveys and bottom trawls were used to identify and collect specimens, and camera sled photographs also were used to determine abundances and spatial distributions for each species. The ophiuroid Ophionotus victoriae, the regular echinoid Sterechinus neumayeri, and one or more species of Porifera were the most abundant taxa during this sampling period. Abundances of O. victoriae varied throughout the annual cycle, peaking in June 2000, and were correlated positively with sedimentation rates. In contrast, abundances of S. neumayeri were consistent throughout the sampling period, except for a peak in June 2000, during austral winter. Peak abundances for both species coincided with a large number of small individuals, indicating apparent recruitment events for O. victoriae and S. neumayeri during this time period. Poriferans, as a group, had statistically similar abundances during each sampling period. Low-abundance species tended to be aggregated on both small and large spatial scales, their distributions probably influenced by reproductive method, gregarious settlement, and food availability. The spatial distribution of S. neumayeri in June 2000 and O. victoriae was random across multiple spatial scales, perhaps in response to food availability and broad environmental tolerances, respectively.

  19. Glaciologist studies Greenland snow conditions and helps calibrate CryoSat instrument

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-08-01

    GREENLAND—On a typically frigid mid-July day at Summit Station, almost smack in the middle of Greenland, with the temperature hovering around -10°C, Elizabeth Morris and John Sweeny were bundled up against the cold atop their black Ski-Doo snowmobiles, which Morris described as being similar to motorcycles on ski tracks. They drove the vehicles—without yet attaching three wooden sleds that would be pulled during their summer scientific traverse across part of central Greenland—on a practice spin along the perimeter of Summit's groomed, approximately 4600-meter × 60-meter snow runway. One of the longest runways in the world, it lies atop 3.2 kilometers of ice, with the horizon stretching in every direction. Morris, a glaciologist who is a senior associate at the Scott Polar Research Institute at Cambridge University, United Kingdom, and Sweeny, her polar guide, were taking advantage of an unexpected extra day at Summit, a scientific research station sponsored by the U.S. National Science Foundation (NSF), before the traverse began. They hoped that the socked-in visibility just a few hours earlier that morning, 16 July, would not be repeated the following day so that a U.S. Air National Guard 109th Airlift Wing C-130 cargo plane would be cleared to fly to Summit from Kangerlussuaq on Greenland's west coast with needed supplies. Morris and Sweeny would load up each sled with about 270 kilograms of gear.

  20. Near-shore sand thickness and stratigraphy mapping with a submerged GPR antenna system; southeast Lake Michigan

    SciTech Connect

    Sauck, W.A.; Seng, D.L. )

    1994-04-01

    Twenty-one shore perpendicular profiles, spaced at nominal 5 km intervals, have been surveyed with a bottom-sled mounted Ground Penetrating Radar (GPR) antenna system between Benton Harbor, MI, and Gary, IN. Either a commercial 500 MHz or a custom 145 MHz antenna were used. The bottom sled also carried an upward looking SONAR transducer to give concurrent water depth, and was towed from the beach out to water depths of 6 meters or more, usually ending about 500 meters from shore. Bedding structures and details are clearly visible on the GPR sections within the sand bars and sand blankets. Bottom morphology and the nature of the sand bodies change markedly from the NE to the SW limits of the survey area. At the NE profiles there are multiple, pronounced (or high amplitude) offshore bars, with the substrate (glacial clay, shale, or silty sand) exposed or nearly exposed between bars. Internal structure is generally foreset or cross bedding in the bars. Sand was thin or missing immediately to the Sw of several other jetty structures in addition to the one at St. Joseph. In general the sand bars became much less pronounced to the SW, and internal structures were dominated by parallel bedding and subtle angular unconformities. Near St. Joseph, the exposed substrate is almost certainly being eroded, even to water depths as great as 6 meters. Thus, the equilibrium bottom profile continues to deepen shoreward, causing the continued threat of bluff erosion in spite of annual beach nourishment efforts at this site.

  1. Abundant box jellyfish, Chironex sp. (Cnidaria: Cubozoa: Chirodropidae), discovered at depths of over 50 m on western Australian coastal reefs.

    PubMed

    Keesing, John K; Strzelecki, Joanna; Stowar, Marcus; Wakeford, Mary; Miller, Karen J; Gershwin, Lisa-Ann; Liu, Dongyan

    2016-02-29

    Box jellyfish cause human fatalities and have a life cycle and habit associated with shallow waters (<5 m) in mangrove creeks, coastal beaches, embayments. In north-western Australia, tow video and epibenthic sled surveys discovered large numbers (64 in a 1500 m tow or 0.05 m(-2)) of Chironex sp. very near to the benthos (<50 cm) at depths of 39-56 m. This is the first record of a population of box jellyfish closely associated with the benthos at such depths. Chironex were not widespread, occurring only in 2 of 33 tow videos and 3 of 41 epibenthic sleds spread over 2000 km(2). All Chironex filmed or captured were on low to medium relief reefs with rich filter feeder communities. None were on soft sediment habitat despite these habitats comprising 49% of all sites. The importance of the reef habitat to Chironex remains unclear. Being associated with filter feeder communities might represent a hazard, and other studies have shown C. fleckeri avoid habitats which represent a risk of entanglement of their tentacles. Most of our observations were made during the period of lowest tidal current flow in the morning. This may represent a period favourable for active hunting for prey close to the seabed.

  2. First identification in energetic particles of characteristic plasma boundaries at Mars and an account of various energetic particle populations close to the planet

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, S. M. P.; Afonin, V.; Yeroshenko, Ye.; Keppler, E.; Kirsch, E.; Schwingenschuh, K.

    1993-05-01

    Signatures of characteristic boundaries, interpreted to be the bow shock and magnetopause with, between them, the magnetosheath, were recorded for the first time in energetic particles (between 30 keV and 3.2 MeV) in the downstream nightside Martian environment by the SLED instrument aboard Phobos 2. Also, energetic particles, interpreted to be oxygen ions, were recorded by SLED at four distinct locations close to Mars. These include (a) anisotropic fluxes at the terminator shocks with energies of up to at least 72 keV; (b) anisotropic fluxes with energies of up to at least 225 keV inside the magnetopause, at a height above the planet of approximately 900 km in the subsolar part of the magnetosphere; (c) fluxes with energies of up to at least 3.2 MeV in the flanks of the magnetosheath displaying quasi-periodic variations (period approximately 45 min) which are synchronous across the recorded energy spectrum and correlated in time with changes in the local magnetic field; and (d) beams of oxygen ions with energies of up to at least 55 keV traveling out along open field lines in the magnetotail with, in some cases, a suggestion of confinement close to the neutral sheet. A preliminary discussion is provided concerning the energization of the various populations of particles identified.

  3. Corrosion of Uranium in Desert Soil, with Application to GCD Source Term M

    SciTech Connect

    ANDERSON, HOWARD L.; BACA, JULIANNE; KRUMHANSL, JAMES L.; STOCKMAN, HARLAN W.; THOMPSON, MOLLIE E.

    1999-09-01

    Uranium fragments from the Sandia Sled Track were studied as analogues for weapons components and depleted uranium buried at the Greater Confinement Disposal (GCD) site in Nevada. The Sled Track uranium fragments originated as weapons mockups and counterweights impacted on concrete and soil barriers, and experienced heating and fragmentation similar to processes thought to affect the Nuclear Weapons Accident Residues (NWAR) at GCD. Furthermore, the Sandia uranium was buried in unsaturated desert soils for 10 to 40 years, and has undergone weathering processes expected to affect the GCD wastes. Scanning electron microscopy, X-ray diffraction and microprobe analyses of the fragments show rapid alteration from metals to dominantly VI-valent oxy-hydroxides. Leaching studies of the samples give results consistent with published U-oxide dissolution rates, and suggest longer experimental periods (ca. 1 year) would be required to reach equilibrium solution concentrations. Thermochemical modeling with the EQ3/6 code indicates that the uranium concentrations in solutions saturated with becquerelite could increase as the pore waters evaporate, due to changes in carbonate equilibria and increased ionic strength.

  4. A rapid method to characterize seabed habitats and associated macro-organisms

    USGS Publications Warehouse

    Anderson, T.J.; Cochrane, G.R.; Roberts, D.A.; Chezar, H.; Hatcher, G.; ,

    2007-01-01

    This study presents a method for rapidly collecting, processing, and interrogating real-time abiotic and biotic seabed data to determine seabed habitat classifications. This is done from data collected over a large area of an acoustically derived seabed map, along multidirectional transects, using a towed small camera-sled. The seabed, within the newly designated Point Harris Marine Reserve on the northern coast of San Miguel Island, California, was acoustically imaged using sidescan sonar then ground-truthed using a towed small camera-sled. Seabed characterizations were made from video observations, and were logged to a laptop computer (PC) in real time. To ground-truth the acoustic mosaic, and to characterize abiotic and biotic aspects of the seabed, a three-tiered characterization scheme was employed that described the substratum type, physical structure (i.e., bedform or vertical relief), and the occurrence of benthic macrofauna and flora. A crucial advantage of the method described here, is that preliminary seabed characterizations can be interrogated and mapped over the sidescan mosaic and other seabed information within hours of data collection. This ability to rapidly process seabed data is invaluable to scientists and managers, particularly in modifying concurrent or planning subsequent surveys.

  5. Abundant box jellyfish, Chironex sp. (Cnidaria: Cubozoa: Chirodropidae), discovered at depths of over 50 m on western Australian coastal reefs

    PubMed Central

    Keesing, John K.; Strzelecki, Joanna; Stowar, Marcus; Wakeford, Mary; Miller, Karen J.; Gershwin, Lisa-Ann; Liu, Dongyan

    2016-01-01

    Box jellyfish cause human fatalities and have a life cycle and habit associated with shallow waters (<5 m) in mangrove creeks, coastal beaches, embayments. In north-western Australia, tow video and epibenthic sled surveys discovered large numbers (64 in a 1500 m tow or 0.05 m−2) of Chironex sp. very near to the benthos (<50 cm) at depths of 39–56 m. This is the first record of a population of box jellyfish closely associated with the benthos at such depths. Chironex were not widespread, occurring only in 2 of 33 tow videos and 3 of 41 epibenthic sleds spread over 2000 km2. All Chironex filmed or captured were on low to medium relief reefs with rich filter feeder communities. None were on soft sediment habitat despite these habitats comprising 49% of all sites. The importance of the reef habitat to Chironex remains unclear. Being associated with filter feeder communities might represent a hazard, and other studies have shown C. fleckeri avoid habitats which represent a risk of entanglement of their tentacles. Most of our observations were made during the period of lowest tidal current flow in the morning. This may represent a period favourable for active hunting for prey close to the seabed. PMID:26924604

  6. Towards a Natural Theory of Dark Energy: Supersymmetric Large Extra Dimensions

    SciTech Connect

    Burgess, C.P.

    2004-12-10

    The first part of this article summarizes the evidence for Dark Energy and Dark Matter, as well as the naturalness issues which plague current theories of Dark Energy. The main point of this part is to argue why these naturalness issues should provide the central theoretical guidance for the search for a successful theory. The second part of the article describes the present status of what I regard as being the best mechanism yet proposed for addressing this issue: Six-dimensional Supergravity with submillimetre-sized Extra Dimensions (Supersymmetric Large Extra Dimensions, or SLED for short). Besides summarizing the SLED proposal itself, this section also describes the tests which this model has passed, the main criticisms which have been raised, and the remaining challenges which remain to be checked. The bottom line is that the proposal survives the tests which have been completed to date, and predicts several distinctive experimental signatures for cosmology, tests of gravity and for accelerator-based particle physics.

  7. Unicompartmental knee prostheses: in vitro wear assessment of the menisci tibial insert after two different fixation methods

    NASA Astrophysics Data System (ADS)

    Affatato, S.; Spinelli, M.; Zavalloni, M.; Carmignato, S.; Lopomo, N.; Marcacci, M.; Viceconti, M.

    2008-10-01

    Knee osteoarthritis is a complex clinical scenario where many biological and mechanical factors influence the severity of articular degenerative changes. Minimally invasive knee prosthetic surgery, with only a compartment replacement (unicompartmental knee replacement), might be a good compromise between osteotomy and total knee prosthesis. The focus of this study was to develop and validate a protocol to assess the fixation method of the femoral components in mechanical simulation, for pre-clinical validation; the wear behaviour of two different fixation frames was quantified and compared. In particular, two different wear tests were conducted using the same knee simulator, the same load profiles and the same kinematics; two different fixation methods were applied to the femoral sleds (synthetic femur and metal block). Surface characterization on both articulating bearings was performed by a roughness measuring machine and coordinate measuring machine. The wear produced by the tibial inserts using the synthetic femur was considerably higher than the wear registered by the metal-block holder. Roughness measurements on femoral sleds showed a limited number of scratches with high Rt values for the metal-block set-up; the damaged surface broadened in the case of femoral condyles and tibial inserts mounted on composite bone, but lower Rt and linear penetration values were measured. The two holding frames showed different wear activities as a consequence of dissimilar dynamic performance. Further observations should be made in vivo to prove the actual importance of synthetic bone simulations and specific material behaviour.

  8. Deep-sea epibenthic echinoderms and a temporally varying food supply: results from a one year time series in the N.E. Pacific

    NASA Astrophysics Data System (ADS)

    Lauerman, Lynn M. L.; Kaufmann, Ronald S.

    Abundance and distribution of epibenthic echinoderms and detrital material at an abyssal site (4100 m) in the N.E. Pacific were examined between June 1994 and June 1995. Camera-sled surveys, time-lapse photographs, and observations from the submersible Alvin revealed a sequence of detrital deposition events. Detrital aggregates were present in summer and fall of 1994 but rare in winter and spring 1995. A layer of white flocculent material covered the sea floor from July through November 1994, constituting the first direct observations of a detrital carpet in this area. Large radiolarian patches also were observed from August 1994 through February 1995. Distribution and abundance of echinoderm species were estimated from camera-sled surveys and showed few consistent temporal patterns. Abundance varied spatially, and distributions generally could not be distinguished from random, in contrast to the clumped pattern observed for detrital aggregates. Statistically, the spatial distributions of several echinoderm species correlated significantly with the distributions of detrital aggregates, but these correlations were not consistent across transects or taxa. The lack of consistent correlation between echinoderm distribution and abundance and the presence of aggregate material is not surprising when the long duration of extensive detrital coverage of the sea floor is considered.

  9. Preliminary Design of a Ramjet for Integration with Ground-Based Launch Assist

    NASA Technical Reports Server (NTRS)

    Sayles, Emily L.

    2008-01-01

    This viewgraph presentation reviews the preliminary design of a ramjet for integration with a ground based launch assist. The reasons for the use of ground-based launch assist and the proposed mechanism for a system are reviewed. The use of a Optimal Trajectory by Implicit Simulation (OTIS), to model the flight and comparison with an actual rocket trajectory is given. The OTIS system is reviewed, The benefits of a launch assist system are analyzed concluding that a launch assist can provide supersonic speeds thus allowing ignition of ramjet without an onboard compressor. This means a further reduction in total launch weight. The Ramjet study is reviewed next. This included a review of the ONX simulations, the verification of the ONX results with the use of Holloman Sled experiment data as derived from the Feasibility of Ramjet Engine Test Capability on The Holloman AFB Sled Track. The conclusion was that the ONX system was not sufficient to meet the needs for the modeling required. The GECAT (Graphical Engine Cycle Analysis Tool) is examined. The results of the GECAT simulations was verified with data from Stataltex and D21 flights. The Next steps are: to create a GECAT Model of a launch assist ramjet, to adjust the geometry to produce the desired thrust, and to survey the ramjet's performance over a range of Mach numbers. The assumptions and requirements of a launch assist ramjet are given, and the acceptable flight regimes are reviewed.

  10. Construction of an unyielding target for large horizontal impacts.

    SciTech Connect

    Ammerman, Douglas James; Davie, Neil Thomas; Kalan, Robert J.

    2010-10-01

    Sandia National Laboratories has constructed an unyielding target at the end of its 2000-foot rocket sled track. This target is made up of approximately 5 million pounds of concrete, an embedded steel load spreading structure, and a steel armor plate face that varies from 10 inches thick at the center to 4 inches thick at the left and right edges. The target/track combination will allow horizontal impacts at regulatory speeds of very large objects, such as a full-scale rail cask, or high-speed impacts of smaller packages. The load-spreading mechanism in the target is based upon the proven design that has been in use for over 20 years at Sandia's aerial cable facility. That target, with a weight of 2 million pounds, has successfully withstood impact forces of up to 25 million pounds. It is expected that the new target will be capable of withstanding impact forces of more than 70 million pounds. During construction various instrumentation was placed in the target so that the response of the target during severe impacts can be monitored. This paper will discuss the construction of the target and provide insights on the testing capabilities at the sled track with this new target.

  11. Unicompartmental knee prostheses: in vitro wear assessment of the menisci tibial insert after two different fixation methods.

    PubMed

    Affatato, S; Spinelli, M; Zavalloni, M; Carmignato, S; Lopomo, N; Marcacci, M; Viceconti, M

    2008-10-07

    Knee osteoarthritis is a complex clinical scenario where many biological and mechanical factors influence the severity of articular degenerative changes. Minimally invasive knee prosthetic surgery, with only a compartment replacement (unicompartmental knee replacement), might be a good compromise between osteotomy and total knee prosthesis. The focus of this study was to develop and validate a protocol to assess the fixation method of the femoral components in mechanical simulation, for pre-clinical validation; the wear behaviour of two different fixation frames was quantified and compared. In particular, two different wear tests were conducted using the same knee simulator, the same load profiles and the same kinematics; two different fixation methods were applied to the femoral sleds (synthetic femur and metal block). Surface characterization on both articulating bearings was performed by a roughness measuring machine and coordinate measuring machine. The wear produced by the tibial inserts using the synthetic femur was considerably higher than the wear registered by the metal-block holder. Roughness measurements on femoral sleds showed a limited number of scratches with high R(t) values for the metal-block set-up; the damaged surface broadened in the case of femoral condyles and tibial inserts mounted on composite bone, but lower R(t) and linear penetration values were measured. The two holding frames showed different wear activities as a consequence of dissimilar dynamic performance. Further observations should be made in vivo to prove the actual importance of synthetic bone simulations and specific material behaviour.

  12. Adaptation of the phase of the human linear vestibulo-ocular reflex (LVOR) and effects on the oculomotor neural integrator

    NASA Technical Reports Server (NTRS)

    Hegemann, S.; Shelhamer, M.; Kramer, P. D.; Zee, D. S.

    2000-01-01

    The phase of the translational linear VOR (LVOR) can be adaptively modified by exposure to a visual-vestibular mismatch. We extend here our earlier work on LVOR phase adaptation, and discuss the role of the oculomotor neural integrator. Ten subjects were oscillated laterally at 0.5 Hz, 0.3 g peak acceleration, while sitting upright on a linear sled. LVOR was assessed before and after adaptation with subjects tracking the remembered location of a target at 1 m in the dark. Phase and gain were measured by fitting sine waves to the desaccaded eye movements, and comparing sled and eye position. To adapt LVOR phase, the subject viewed a computer-generated stereoscopic visual display, at a virtual distance of 1 m, that moved so as to require either a phase lead or a phase lag of 53 deg. Adaptation lasted 20 min, during which subjects were oscillated at 0.5 Hz/0.3 g. Four of five subjects produced an adaptive change in the lag condition (range 4-45 deg), and each of five produced a change in the lead condition (range 19-56 deg), as requested. Changes in drift on eccentric gaze suggest that the oculomotor velocity-to-position integrator may be involved in the phase changes.

  13. Upper and lower neck loads in belted human surrogates in frontal impacts.

    PubMed

    Yoganandan, Narayan; Pintar, Frank A; Moore, Jason; Rinaldi, James; Schlick, Michael; Maiman, Dennis J

    2012-01-01

    The upper and lower neck loads in the restrained Hybrid III dummy and Test Device for Human Occupant Restraint (THOR) were computed in simulated frontal impact sled tests at low, medium, and high velocities; repeatability performance of the two dummies were evaluated at all energy inputs; peak forces and moments were compared with computed loads at the occipital condyles and cervical-thoracic junctions from tests using post mortem human surrogates (PMHS). A custom sled buck was used to position the surrogates. Repeated tests were conducted at each velocity for each dummy and sufficient time was allowed to elapse between the two experiments. The upper and lower neck forces and moments were determined from load cell measures and its locations with respect to the ends of the neck. Both dummies showed good repeatability for axial and shear forces and bending moments at all changes in velocity inputs. Morphological characteristics in the neck loading responses were similar in all surrogates, although the peak magnitudes of the variables differed. In general, the THOR better mimicked the PMHS response than the Hybrid III dummy, and factors such as neck design and chest compliance were attributed to the observed variations. While both dummies were not designed for use at the two extremes of the tested velocities, results from the present study indicate that, currently the THOR may be the preferred anthropomorphic testing device in crashworthiness research studies and full-scale vehicle tests at all velocities.

  14. Study of cervical muscle response and injury of driver during a frontal vehicle collision.

    PubMed

    Gao, Zhenhai; Li, Chuzhao; Hu, Hongyu; Zhao, Hui; Chen, Chaoyang; Yu, Huili

    2015-01-01

    Frontal vehicle collisions can cause injury to a driver's cervical muscles resulting from intense changes in muscle strain and muscle load. This study investigated the influence of collision forces in a sled test environment using a modified Hybrid III 50th percentile dummy equipped with simulated spring-type muscles. Cervical muscle responses including strain and load of the sternocleidomastoid (SCM), splenius capitis (SPL), and trapezius (TRP) were analyzed, and muscle injury was assessed. The SCM, SPL, and TRP suffered average peak muscle strains of 21%, 40%, and 23%, respectively, exceeding the injury threshold. The average peak muscle loads of the SCM, SPL and TRP were 11 N, 25 N, and 25 N, respectively, lower than the ultimate failure load. The SPL endured the largest injury, while the injuries to the SCM and TRP were relatively small. This is a preliminary study to assess the cervical muscle of driver during a frontal vehicle collision. This study provides a foundation for investigating the muscle response and injury in sled test environments, which can lead to the improvement of occupant protections.

  15. Evaluation of chest injury mechanisms in nearside oblique frontal impacts.

    PubMed

    Iraeus, Johan; Lindquist, Mats; Wistrand, Sofie; Sibgård, Elin; Pipkorn, Bengt

    2013-01-01

    Despite the use of seat belts and modern safety systems, many automobile occupants are still seriously injured or killed in car crashes. Common configurations in these crashes are oblique and small overlap frontal impacts that often lead to chest injuries.To evaluate the injury mechanism in these oblique impacts, an investigation was carried out using mathematical human body model simulations. A model of a simplified vehicle interior was developed and validated by means of mechanical sled tests with the Hybrid III dummy. The interior model was then combined with the human body model THUMS and validated by means of mechanical PMHS sled tests. Occupant kinematics as well as rib fracture patterns were predicted with reasonable accuracy.The final model was updated to conform to modern cars and a simulation matrix was run. In this matrix the boundary conditions, ΔV and PDOF, were varied and rib fracture risk as a function of the boundary conditions was evaluated using a statistical framework.In oblique frontal impacts, two injury producing mechanisms were found; (i) diagonal belt load and (ii) side structure impact. The second injury mechanism was found for PDOFs of 25°-35°, depending on ΔV. This means that for larger PDOFs, less ΔV is needed to cause a serious chest injury.

  16. Environmental Restoration Operations Consolidated Quarterly Report: July-September 2016

    SciTech Connect

    Cochran, John R.

    2017-01-01

    This Environmental Restoration Operations (ER) Consolidated Quarterly Report (ER Quarterly Report) provides the status of ongoing corrective action activities being implemented at Sandia National Laboratories, New Mexico (SNL/NM) during the July, August, and September 2016 quarterly reporting period. The Solid Waste Management Units (SWMUs) and Areas of Concern (AOCs) identified for corrective action at SNL/NM are listed in Table I-1. Sections I.2.1 and I.2.2 summarize the work completed during this quarter. Section I.2.1 summarizes the quarterly activities at sites undergoing corrective action field activities. Field activities are conducted at the three groundwater AOCs (Burn Site Groundwater [BSG AOC], Technical Area [TA]-V Groundwater [TAVG AOC], and Tijeras Arroyo Groundwater [TAG AOC]). Section I.2.2 summarizes quarterly activities at sites where the New Mexico Environment Department (NMED) issued a certificate of completion and the sites are in the corrective action complete (CAC) regulatory process. Currently, SWMUs 8 and 58, 68, 149, 154, and 502 are in the CAC regulatory process. Corrective action activities are deferred at the Long Sled Track (SWMU 83), the Gun Facilities (SWMU 84), and the Short Sled Track (SWMU 240) because these three sites are active mission facilities. These three active sites are located in TA-III.

  17. Modelling the Sub-mm Emission of Galaxies Over Cosmic Time

    NASA Astrophysics Data System (ADS)

    Popping, G.; Pérez-Beaupuits, J. P.

    2015-12-01

    At redshift z˜ 1-3 the star-formation rate density (SFRD) of the Universe reached its peak, after which it dropped towards its current day value. ALMA allows us to observe atoms and molecules like C, C+, [OI], CO, and HCN for large groups of star- forming (SF) galaxies during this cosmic epoch. Emission lines from these species are good tracers of the properties of the interstellar medium (ISM) out of which new stars form. This proceeding describes our efforts to model the sub-mm line emission of these elements in SF galaxies, using the combination of a semi-analytic model of galaxy formation and a radiative transfer code. The presented model successfully reproduces CO scaling relations for local and high-redshift galaxies. Here we use this model to make predictions for the CO Spectral Line Energy Distribution (CO SLED) of galaxies at redshift z=0.0, z=1.2, and z=2.0. We discuss what physical processes drive the change in CO SLED shape with redshift and discuss future strategies to observe this.

  18. Motion perception during tilt and translation after space flight

    NASA Astrophysics Data System (ADS)

    Clément, Gilles; Wood, Scott J.

    2013-11-01

    Preliminary results of an ongoing study examining the effects of space flight on astronauts' motion perception induced by independent tilt and translation motions are presented. This experiment used a sled and a variable radius centrifuge that translated the subjects forward-backward or laterally, and simultaneously tilted them in pitch or roll, respectively. Tests were performed on the ground prior to and immediately after landing. The astronauts were asked to report about their perceived motion in response to different combinations of body tilt and translation in darkness. Their ability to manually control their own orientation was also evaluated using a joystick with which they nulled out the perceived tilt while the sled and centrifuge were in motion. Preliminary results confirm that the magnitude of perceived tilt increased during static tilt in roll after space flight. A deterioration in the crewmember to control tilt using non-visual inertial cues was also observed post-flight. However, the use of a tactile prosthesis indicating the direction of down on the subject's trunk improved manual control performance both before and after space flight.

  19. The molecular gas in luminous infrared galaxies - I. CO lines, extreme physical conditions and their drivers

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Padelis P.; van der Werf, Paul P.; Xilouris, E. M.; Isaak, K. G.; Gao, Yu; Mühle, S.

    2012-11-01

    We report results from a large molecular line survey of luminous infrared galaxies (LIRGs; L IR ≳1011 L) in the local Universe (z ≤ 0.1), conducted during the last decade with the James Clerk Maxwell Telescope and the IRAM 30-m telescope. This work presents the CO and 13CO line data for 36 galaxies, further augmented by multi-J total CO line luminosities available for other infrared (IR) bright galaxies from the literature. This yields a combined sample of N = 70 galaxies with the star formation (SF) powered fraction of their IR luminosities spanning L IR (*)˜(1010-2×1012) L and a wide range of morphologies. Simple comparisons of their available CO spectral line energy distributions (SLEDs) with local ones, as well as radiative transfer models, discern a surprisingly wide range of average interstellar medium (ISM) conditions, with most of the surprises found in the high-excitation regime. These take the form of global CO SLEDs dominated by a very warm (Tkin ≳100 K) and dense (n ≥ 104 cm-3) gas phase, involving galaxy-sized (˜(few) × 109 M⊙) gas mass reservoirs under conditions that are typically found only for ˜(1-3) per cent of mass per typical SF molecular cloud in the Galaxy. Furthermore, some of the highest excitation CO SLEDs are found in ultraluminous infrared galaxies (ULIRGs; LIR ≥ 1012 L⊙) and surpass even those found solely in compact SF-powered hot spots in Galactic molecular clouds. Strong supersonic turbulence and high cosmic ray energy densities rather than far-ultraviolet/optical photons or supernova remnant induced shocks from individual SF sites can globally warm the large amounts of dense gas found in these merger-driven starbursts and easily power their extraordinary CO line excitation. This exciting possibility can now be systematically investigated with Herschel and the Atacama Large Milimeter Array (ALMA). As expected for an IR-selected (and thus SF rate selected) galaxy sample, only few 'cold' CO SLEDs are found, and for

  20. On-ice vibroseis and snowstreamer systems for geoscientific research

    NASA Astrophysics Data System (ADS)

    Eisen, Olaf; Hofstede, Coen; Diez, Anja; Kristoffersen, Yngve; Lambrecht, Astrid; Mayer, Christoph; Blenkner, Rick; Hilmarsson, Sverrir

    2015-03-01

    We present implementations of vibroseis system configurations with a snowstreamer for over-ice long-distance seismic traverses (>100 km). The configurations have been evaluated in Antarctica on ice sheet and ice shelf areas in the period 2010-2014. We discuss results of two different vibroseis sources: Failing Y-1100 on skis with a peak force of 120 kN in the frequency range 10-110 Hz; IVI EnviroVibe with a nominal peak force of 66 kN in the nominal frequency range 10-300 Hz. All measurements used a well-established 60 channel 1.5 km snowstreamer for the recording. Employed forces during sweeps were limited to less than 80% of the peak force. Maximum sweep frequencies, with a typical duration of 10 s, were 100 and 250 Hz for the Failing and EnviroVibe, respectively. Three different concepts for source movement were employed: the Failing vibrator was mounted with wheels on skis and pulled by a Pistenbully snow tractor. The EnviroVibe was operated self-propelled on Mattracks on the Antarctic plateau. This lead to difficulties in soft snow. For later implementations the EnviroVibe with tracks was put on a polyethylene (PE) sled. The sled had a hole in the center to lower the vibrator baseplate directly onto the snow surface. With the latter setup, data production varied between 20 km/day for 6-fold and 40 km/day for single fold for 9 h/day of measurements. The combination of tracks with the PE-sled was especially advantageous on hard and rough surfaces because of the flexibility of each component and the relatively lose mounting. The systems presented here are suitable to obtain data of subglacial and sub-seabed sediment layers and englacial layering in comparable quality as obtained from marine geophysics and land-based explosive surveys. The large offset aperture of the streamer overcomes limitations of radar systems for imaging of steep along-track subglacial topography. With joint international scientific and logistic efforts, large-scale mapping of Antarctica

  1. Consideration of wear rates at high velocity

    NASA Astrophysics Data System (ADS)

    Hale, Chad S.

    The development of the research presented here is one in which high velocity relative sliding motion between two bodies in contact has been considered. Overall, the wear environment is truly three-dimensional. The attempt to characterize three-dimensional wear was not economically feasible because it must be analyzed at the micro-mechanical level to get results. Thus, an engineering approximation was carried out. This approximation was based on a metallographic study identifying the need to include viscoplasticity constitutive material models, coefficient of friction, relationships between the normal load and velocity, and the need to understand wave propagation. A sled test run at the Holloman High Speed Test Track (HHSTT) was considered for the determination of high velocity wear rates. In order to adequately characterize high velocity wear, it was necessary to formulate a numerical model that contained all of the physical events present. The experimental results of a VascoMax 300 maraging steel slipper sliding on an AISI 1080 steel rail during a January 2008 sled test mission were analyzed. During this rocket sled test, the slipper traveled 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s. This type of environment was never considered previously in terms of wear evaluation. Each of the features of the metallography were obtained through micro-mechanical experimental techniques. The byproduct of this analysis is that it is now possible to formulate a model that contains viscoplasticity, asperity collisions, temperature and frictional features. Based on the observations of the metallographic analysis, these necessary features have been included in the numerical model, which makes use of a time-dynamic program which follows the movement of a slipper during its experimental test run. The resulting velocity and pressure functions of time have been implemented in the explicit finite element code, ABAQUS. Two-dimensional, plane strain models

  2. The molecular gas in Luminous Infrared Galaxies: a new emergent picture

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Padelis P.; Zhang, Zhi-Yu; Weiss, Axel; van der Werf, Paul; Isaak, Kate; Gao, Yu; Xilouris, Manolis; Greve, Thomas R.

    2013-03-01

    Results from a large, multi-J CO, 13CO, and HCN line survey of Luminous Infrared Galaxies (LIRGs: LIR≥ 1010 L⊙) in the local Universe (z≤0.1), complemented by CO J=4-3 up to J=13-12 observations from the Herschel Space Observatory (HSO), paints a new picture for the average conditions of the molecular gas of the most luminous of these galaxies with turbulence and/or large cosmic ray (CR) energy densities UCR rather than far-UV/optical photons from star-forming sites as the dominant heating sources. Especially in ULIRGs (LIR>1012 L⊙) the Photon Dominated Regions (PDRs) can encompass at most a few % of their molecular gas mass while the large UCR˜ 103 UCR, Galaxy, and the strong turbulence in these merger/starbursts, can volumetrically heat much of their molecular gas to Tkin˜ (100-200) K, unhindered by the high dust extinctions. Moreover the strong supersonic turbulence in ULIRGs relocates much of their molecular gas at much higher average densities (≥104 cm-3) than in isolated spirals (˜ 102-103 cm-3). This renders low-J CO lines incapable of constraining the properties of the bulk of the molecular gas in ULIRGs, with substantial and systematic underestimates of its mass possible when only such lines are used. Finally a comparative study of multi-J HCN lines and CO SLEDs from J=1-0 up to J=13-12 of NGC 6240 and Arp 193 offers a clear example of two merger/starbursts whose similar low-J CO SLEDs, and LIR/LCO,1-0 and LHCN, 1-0/LCO,1-0 ratios (proxies of the so-called SF efficiency and dense gas mass fraction), yield no indications about their strongly diverging CO SLEDs beyond J=4-3, and ultimately the different physical conditions in their molecular ISM. The much larger sensitivity of ALMA and its excellent site in the Atacama desert now allows the observations necessary to assess the dominant energy sources of the molecular gas and its mass in LIRGs without depending on the low-J CO lines.

  3. Genomic deletion of CNGB3 is identical by descent in multiple canine breeds and causes achromatopsia

    PubMed Central

    2013-01-01

    Background Achromatopsia is an autosomal recessive disease characterized by the loss of cone photoreceptor function that results in day-blindness, total colorblindness, and decreased central visual acuity. The most common causes for the disease are mutations in the CNGB3 gene, coding for the beta subunit of the cyclic nucleotide-gated channels in cones. CNGB3-achromatopsia, or cone degeneration (cd), is also known to occur in two canine breeds, the Alaskan malamute (AM) and the German shorthaired pointer. Results Here we report an in-depth characterization of the achromatopsia phenotype in a new canine breed, the miniature Australian shepherd (MAS). Genotyping revealed that the dog was homozygous for a complete genomic deletion of the CNGB3 gene, as has been previously observed in the AM. Identical breakpoints on chromosome 29 were identified in both the affected AM and MAS with a resulting deletion of 404,820 bp. Pooled DNA samples of unrelated purebred Australian shepherd, MAS, Siberian husky, Samoyed and Alaskan sled dogs were screened for the presence of the affected allele; one Siberian husky and three Alaskan sled dogs were identified as carriers. The affected chromosomes from the AM, MAS, and Siberian husky were genotyped for 147 SNPs in a 3.93 Mb interval within the cd locus. An identical shared affected haplotype, 0.5 Mb long, was observed in all three breeds and defined the minimal linkage disequilibrium (LD) across breeds. This supports the idea that the mutated allele was identical by descent (IBD). Conclusion We report the occurrence of CNGB3-achromatopsia in a new canine breed, the MAS. The CNGB3-deletion allele previously described in the AM was also observed in a homozygous state in the affected MAS, as well as in a heterozygous carrier state in a Siberian husky and Alaskan sled dogs. All affected alleles were shown to be IBD, strongly suggesting an affected founder effect. Since the MAS is not known to be genetically related to the AM, other

  4. Multivariate head injury threshold measures for various sized children seated behind vehicle seats in rear impacts.

    PubMed

    Saczalski, Kenneth; Sances, Anthony; Kumaresan, Srirangam; Pozzi, Mark; Saczalski, Todd; Burton, J L; Lewis, P

    2004-01-01

    Government recommendations to place children into the rear areas of motor vehicles to avoid airbag induced injuries have been complicated by the fact that most adult occupied front seats will collapse into the rear area during rear-impacts, and thus pose another potentially serious injury hazard to rear-seated children. Many variables affect whether or not a front seat occupant will collapse into the rear child, and whether that interaction could be injurious to the child. For instance, the severity of rear impact, coupled with front and rear occupant sizes (mass and stature), and the level of front seat strength, all interrelate to influence whether or not a rear seated child is likely to be impacted and possibly injured. The most common types of child injuries in these instances are head and chest injuries. In this study, a "high-low" experimental method was employed with a multi-level "factorial analysis" technique to study "multivariate" biomechanics of child head injury potential determined from rear-seated 3 and 6 year-old child surrogates in different types of vehicle bodies mounted to a sled system. The sled-buck systems were towed rearward into crushable barriers that matched the crash pulses of the vehicle types being tested. Various sizes of adult surrogates (i.e. 50 kg up to 110 kg), seated in both the "typical" low strength "single recliner" collapsing type front seat (i.e. 3.2 kN) and a much stronger "belt-integrated" seat design (i.e. up to 14.5 kN), were tested in the two different "sled body-buck" set-ups at various impact levels (i.e. 22.5 to 50 kph). One set-up used a popular minivan vehicle body with "built-in booster" seats for the 3 year-old. The other used a 4-door family sedan vehicle body with the 6 year-old in a standard rear bench seat. The parameters of the tests enabled the experimental data to be combined into polynomial "head injury" functions of the independent variables so the "likelihood" of rear child head-injury potential could

  5. [Continuous renal replacement therapies (CRRT) will remain the most widely adopted dialysis modality in the critically ill].

    PubMed

    Morabito, S; Pistolesi, V; Cibelli, L; Pierucci, A

    2009-01-01

    In the last 10-15 years, user-friendly continuous renal replacement therapy (CRRT) machines have played a major role in increasing the popularity of these techniques in intensive care settings. At present it is not clear which modality of renal replacement therapy (RRT) is optimal for critically ill patients with acute kidney injury (AKI). The choice between different modalities should therefore not be based on unproven ''outcome'' advantages but on evaluation of the clinical picture and logistical circumstances. In hypercatabolic patients, CRRT and sustained low-efficiency dialysis (SLED) have been shown to provide similar metabolic control, but uncontrolled studies suggested a better hemodynamic stability during CRRT, intended as a higher mean arterial pressure and/or less frequent need to increase inotropic or vasoactive drugs. The incidence of hemorrhagic complications is higher with CRRT; however, in particular conditions, such as in patients at high risk of bleeding, CRRT can be performed without anticoagulation or with the use of alternative anticoagulation protocols. Among the different modalities, regional anticoagulation with citrate appears to be the most promising, and the continuous development of simplified protocols for citrate CRRT might facilitate the more extensive use of this technique in the near future. The presence of a mismatch between prescribed and delivered dialysis dose is frequently reported as an important drawback of CRRT. However, data from a recent study designed to evaluate the prognostic impact of the intensity of renal support in critically ill patients with AKI showed that the target Kt/V was obtained in only 67-69% of intermittent hemodialysis (IHD) sessions. Data from several studies comparing the costs of different RRT modalities showed that CRRT is more expensive than IHD or SLED. However, the costs related to SLED can fluctuate within a wide range and in particular settings the higher costs of CRRT could be partially

  6. Development of Side Impact Thoracic Injury Criteria and Their Application to the Modified ES-2 Dummy with Rib Extensions (ES-2re).

    PubMed

    Kuppa, Shashi; Eppinger, Rolf H; McKoy, Felicia; Nguyen, Thuvan; Pintar, Frank A; Yoganandan, Narayan

    2003-10-01

    Forty-two side impact cadaver sled tests were conducted at 24 and 32 km/h impact speeds into rigid and padded walls. The post-mortem human subjects were instrumented with accelerometers on the ribs and spine and chest bands around the thorax and abdomen to characterize their mechanical response during the impact. Load cells at the wall measured the impact force at the level of the thorax, abdomen, pelvis, and lower extremities. The resulting injuries were determined through detailed autopsy and radiography. Rib fractures with or without associated hemo/pneumo thorax or flail chest were the most common injury with severity ranging from AIS=0 to 5. Full and half thorax deflections were computed from the chest band data. The cadaver test data was analyzed using ANOVA and logistic regression. The age of the subject at the time of death had influence on injury outcome while gender and mass of the subject had little or no influence on injury outcome. Existing side impact injury criteria were evaluated such as Thoracic Trauma Index (TTI), Average Spinal Acceleration (ASA), full and half thorax deflections, chest velocity and viscous criterion, and contact force. The analysis results indicate that maximum normalized average half thorax deflection was the best predictor of AIS>/=3 and AIS>/=4 thoracic injury. TTI and upper spine accelerations were also good predictors of thoracic injury. Sixteen side impact sled tests were also conducted with the modified ES-2 dummy with rib extensions (ES-2re) under similar impact conditions as the cadaver tests. The rib extensions were added to the original ES-2 dummy ribs to prevent the "seat grabbing" action of the back plate that was noticed in some side impact vehicle crash tests with the ES-2 dummy. A separate analysis was conducted using the injury response and subject characteristics from the cadaver tests and the physical parameters derived from measurements on the ES-2re dummy in sled tests under similar conditions as the cadaver

  7. Final Environmental Impact Statement, Peacekeeper in Minuteman Silos, F. E. Warren AFB, Wyoming. Volume 2. Public Comments.

    DTIC Science & Technology

    1984-01-01

    1983. Idottents "ona tmtty -~L.l -Sa to oo-1 oe-t tould eto A010 td opfoicy O~eo SOfpc by %0t-6t0op 21, 1983, So that 00* Crtoait orsPopnse Coo- o...dil.Iy ... hcbtPat*ooo ayft.t0050Ot 0.to.5otlo o.t ,t0 . ott Ott l hoMa i t mit tooto 1.0 Sled td - 00..t000.000 wa tOw -1tO o from...8.15 Th.’ 32iO.S.1.- per-trf 1aiit. b "ee 4’. fe. IMA*l.IMML td P ld-I -a," h ut-,aaa 4L ~ ~ po..ti 11.. ~ la Th -1-6 f to .~ OoL tta t t ttoa1

  8. S-Band Loads for SLAC Linac

    SciTech Connect

    Krasnykh, A.; Decker, F.-J.; LeClair, R.; /INTA Technologies, Santa Clara

    2012-08-28

    The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.

  9. Measuring aberrations in the rat brain by coherence-gated wavefront sensing using a Linnik interferometer

    PubMed Central

    Wang, Jinyu; Léger, Jean-François; Binding, Jonas; Boccara, A. Claude; Gigan, Sylvain; Bourdieu, Laurent

    2012-01-01

    Aberrations limit the resolution, signal intensity and achievable imaging depth in microscopy. Coherence-gated wavefront sensing (CGWS) allows the fast measurement of aberrations in scattering samples and therefore the implementation of adaptive corrections. However, CGWS has been demonstrated so far only in weakly scattering samples. We designed a new CGWS scheme based on a Linnik interferometer and a SLED light source, which is able to compensate dispersion automatically and can be implemented on any microscope. In the highly scattering rat brain tissue, where multiply scattered photons falling within the temporal gate of the CGWS can no longer be neglected, we have measured known defocus and spherical aberrations up to a depth of 400 µm. PMID:23082292

  10. Helium and neon isotopes in deep Pacific Ocean sediments

    NASA Technical Reports Server (NTRS)

    Nier, A. O.; Schlutter, D. J.; Brownlee, D. E.

    1990-01-01

    Helium and neon concentration measurements, along with isotope ratio determinations, have been made for particles collected in the deep Pacific with a magnetic sled, and they are believed to be of extraterrestrial origin. Analyses were made for samples consisting of composites of many extremely fine particles and for several individual particles large enough to contain sufficient gas for analysis but small enough to escape melting in their passage through the atmosphere. Step-heating was employed to extract the gas. Cosmic-ray spallation products or solar-wind helium and neon, if present, were not abundant enough to account for the isotopic compositions measured. In the case of the samples of magnetic fines, the low temperature extractions provided elemental and isotopic ratios in the general range found for the primordial gas in carbonaceous chondrites and gas-rich meteorites. The isotopic ratios found in the high temperature extractions suggest the presence of solar-flare helium and neon.

  11. 7. View of interior of Lock No. 2 on George ...

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

    7. View of interior of Lock No. 2 on George washington 'Potowmack' Canal at Great Falls, Virginia. This lock is about 15 ft. in depth and possibly 70 or 60 ft. in length. Some 15 or 20 years ago, when a restoration was crudely attempted, the old oaken flooring, which was invariably placed at the bottom of canal locks, was roughly torn up and destroyed. The trunks and stumps of gigantic trees still remain from this restorative effort, and their girth indicates again the antiquity of this evidence of George Washington's work as an engineer. The stones are of the red Seneca type and were evidently ferried from the Maryland side above the dam and then brought by sled or rollers to this location. These stones were beautifully hand-cut and fitted with ... - Potowmack Company: Great Falls Canal, Lock No. 2, Great Falls, Fairfax County, VA

  12. Results from Sandia National Laboratories/Lockheed Martin Electromagnetic Missile Launcher (EMML).

    SciTech Connect

    Lockner, Thomas Ramsbeck; Skurdal, Ben; Gaigler, Randy; Basak, L; Root, G; Aubuchon, Matthew S.; Turman, Bobby N.; Floyd, Mendel D.

    2005-05-01

    Sandia national laboratories (SNL) and lockheed martin MS2 are designing an electromagnetic missile launcher (EMML) for naval applications. The EMML uses an induction coilgun topology with the requirement of launching a 3600 lb. missile up to a velocity of 40 m/s. To demonstrate the feasibility of the electromagnetic propulsion design, a demonstrator launcher was built that consists of approximately 10% of the propulsion coils needed for a tactical design. The demonstrator verified the design by launching a 1430 lb weighted sled to a height of 24 ft in mid-December 2004 (Figure 1). This paper provides the general launcher design, specific pulsed power system component details, system operation, and demonstration results.

  13. Experiments on the Richtmyer-Meshkov Instability of Incompressible Fluids

    NASA Technical Reports Server (NTRS)

    Jacobs, J.; Niederhaus, C.

    2000-01-01

    Richtmyer-Meshkov (R-M) instability occurs when two different density fluids are impulsively accelerated in the direction normal to their nearly planar interface. The instability causes small perturbations on the interface to grow and possibly become turbulent given the proper initial conditions. R-M instability is similar to the Rayleigh-Taylor (R-T) instability, which is generated when the two fluids undergo a constant acceleration. R-M instability is a fundamental fluid instability that is important to fields ranging from astrophysics to high-speed combustion. For example, R-M instability is currently the limiting factor in achieving a net positive yield with inertial confinement fusion. The experiments described here utilize a novel technique that circumvents many of the experimental difficulties previously limiting the study of the R-M instability. A Plexiglas tank contains two unequal density liquids and is gently oscillated horizontally to produce a controlled initial fluid interface shape. The tank is mounted to a sled on a high speed, low friction linear rail system, constraining the main motion to the vertical direction. The sled is released from an initial height and falls vertically until it bounces off of a movable spring, imparting an impulsive acceleration in the upward direction. As the sled travels up and down the rails, the spring retracts out of the way, allowing the instability to evolve in free-fall until impacting a shock absorber at the end of the rails. The impulsive acceleration provided to the system is measured by a piezoelectric accelerometer mounted on the tank, and a capacitive accelerometer measures the low-level drag of the bearings. Planar Laser-Induced Fluorescence is used for flow visualization, which uses an Argon ion laser to illuminate the flow and a CCD camera, mounted to the sled, to capture images of the interface. This experimental study investigates the instability of an interface between incompressible, miscible liquids

  14. Radar sensor for an autonomous Antarctic explorer

    NASA Astrophysics Data System (ADS)

    Foessel, Alex; Apostolopoulos, Dimi; Whittaker, William L.

    1999-01-01

    The localization and identification of antarctic meteorites is a task of great scientific interest and with implications to planetary exploration. Autonomous search for antarctic meteorites presents a profound technical challenge. Ground Penetrating Radar (GPR) holds the prospect to safeguard antarctic robot from terrain dangers and detect subsurface objects. In January 1998, we validated a 500 MHz GPR sensor as part of a field robotic technology demonstration at Patriot Hills, Antarctica. We deployed the sensor from a sled and integrate with position and attitude instruments to perform field measurements. Data was acquired under different conditions and in multiple locations. The radar detected hidden crevasses from 50 cm. distance, thus showing its merit as a rover safeguarding device. It also localized 5 cm. rocks ins now and ice. Moreover, the radar data was used to characterize snow/ice/bedrock stratigraphy. GPR position measurements enabled ground truth and mapping of the location of hazards and interesting subsurface objects and features.

  15. 3. Credit USAF, ca. 1945. Original housed in the Records ...

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

    3. Credit USAF, ca. 1945. Original housed in the Records of the Defense Intelligence Agency. Record Group 373. National Archives. Cartographic and Architectural Branch. Washington, D.C. Aerial orthophoto map 16PS5M79-IV23 of Muroc Flight Test Base (North Base), north faces up with runway at the top and Rogers Dry Lake at the lower right. Ammunition huts (not extant in 1995) appear in a cluster just south of the west end of the runway. Note runway markings on lakebed. Linear feature at very top of image is rocket sled test track designed and built 1944-1945. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  16. Angle interferometer cross axis errors

    SciTech Connect

    Bryan, J.B.; Carter, D.L.; Thompson, S.L.

    1994-01-01

    Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them by remachining the reference surfaces.

  17. Review and update of lens and grid schlieren and motion camera schlieren

    NASA Astrophysics Data System (ADS)

    Weinstein, L. M.

    2010-04-01

    Optical density variation in fluids and transparent solids can often be studied by examining the effect of refraction of light passing through the medium. The schlieren technique has proven to be particularly well suited for these applications, and has been widely used for wind-tunnel studies. Newer variations of this technique have extended it to a wide range of applications. The lens and grid schlieren systems have been used to examine aerodynamic flow fields that were previously difficult to study with conventional schlieren systems. Motion camera schlieren was developed to obtain the flow field around aircraft in flight and rocket sleds. This paper gives an up to date review of the background and development of the lens and grid schlieren and motion camera schlieren techniques and includes examples of many of the flows studied using the techniques, including some previously unpublished ones. In addition, some preliminary results from new versions of both types of systems are described.

  18. The aerodynamic challenges of SRB recovery

    NASA Technical Reports Server (NTRS)

    Bacchus, D. L.; Kross, D. A.; Moog, R. D.

    1985-01-01

    Recovery and reuse of the Space Shuttle solid rocket boosters was baselined to support the primary goal to develop a low cost space transportation system. The recovery system required for the 170,000-lb boosters was for the largest and heaviest object yet to be retrieved from exoatmospheric conditions. State-of-the-art design procedures were ground-ruled and development testing minimized to produce both a reliable and cost effective system. The ability to utilize the inherent drag of the boosters during the initial phase of reentry was a key factor in minimizing the parachute loads, size and weight. A wind tunnel test program was devised to enable the accurate prediction of booster aerodynamic characteristics. Concurrently, wind tunnel, rocket sled and air drop tests were performed to develop and verify the performance of the parachute decelerator subsystem. Aerodynamic problems encountered during the overall recovery system development and the respective solutions are emphasized.

  19. Measurements of ultimate accelerating gradients in the SLAC disk-loaded structure

    SciTech Connect

    Wang, J.W.; Loew, G.A.

    1985-03-01

    This paper is a status report on an on-going program at SLAC to study accelerator structures under high-gradient electric field conditions. The study is a part of a much broader program dealing with future linear colliders. The accelerating gradient that might be achievable in such machines is a crucial parameter because once the beam energy is selected, the gradient determines the length of the linac and directly or indirectly affects the choice of many other parameters. To reach 100 MV/m in a conventional 3 m constant-gradient section without SLED, one would need a klystron with a peak power output of 900 MW. Since such a tube is not available, we decided to use a short standing-wave section in which the resonant fields can build up. The design criteria for this section, the fabrication, matching and tuning, the experimental set-up and the results are described. 6 refs., 5 figs., 1 tab.

  20. Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Shane, S. J.

    1985-01-01

    A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is explored. An energy-absorbing test seat was designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions, was conducted at a sled test facility. Comparative tests with operational F-111 crewseats were also conducted. After successful dynamic testing of the seat, more testing was conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests were conducted. The vertical drop tests were used to obtain comparative data between the energy-absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series.

  1. Technology requirements for advanced earth-orbital transportation systems

    NASA Technical Reports Server (NTRS)

    Haefeli, R. C.; Littler, E. G.; Hurley, J. B.; Winter, M. G.

    1977-01-01

    Areas of advanced technology that are either critical or offer significant benefits to the development of future Earth-orbit transportation systems were identified. Technology assessment was based on the application of these technologies to fully reusable, single-stage-to-orbit (SSTO) vehicle concepts with horizontal landing capability. Study guidelines included mission requirements similar to space shuttle, an operational capability begining in 1995, and main propulsion to be advanced hydrogen-fueled rocket engines. Also evaluated was the technical and economic feasibility of this class of SSTO concepts and the comparative features of three operational take-off modes, which were vertical boost, horizontal sled launch, and horizontal take-off with subsequent inflight fueling. Projections of both normal and accelerated technology growth were made. Figures of merit were derived to provide relative rankings of technology areas. The influence of selected accelerated areas on vehicle design and program costs was analyzed by developing near-optimum point designs.

  2. HOT WATER DRILL FOR TEMPERATE ICE.

    USGS Publications Warehouse

    Taylor, Philip L.

    1984-01-01

    The development of a high-pressure hot-water drill is described, which has been used reliably in temperate ice to depths of 400 meters with an average drill rate of about 1. 5 meters per minute. One arrangement of the equipment weighs about 500 kilograms, and can be contained on two sleds, each about 3 meters long. Simplified performance equations are given, and experiments with nozzle design suggest a characteristic number describing the efficiency of each design, and a minimum bore-hole diameter very close to 6 centimeters for a hot water drill. Also discussed is field experience with cold weather, water supply, and contact with englacial cavities and the glacier bed.

  3. Neural processing of gravity information

    NASA Technical Reports Server (NTRS)

    Schor, Robert H.

    1992-01-01

    The goal of this project was to use the linear acceleration capabilities of the NASA Vestibular Research Facility (VRF) at Ames Research Center to directly examine encoding of linear accelerations in the vestibular system of the cat. Most previous studies, including my own, have utilized tilt stimuli, which at very low frequencies (e.g., 'static tilt') can be considered a reasonably pure linear acceleration (e.g., 'down'); however, higher frequencies of tilt, necessary for understanding the dynamic processing of linear acceleration information, necessarily involves rotations which can stimulate the semicircular canals. The VRF, particularly the Long Linear Sled, has promise to provide controlled pure linear accelerations at a variety of stimulus frequencies, with no confounding angular motion.

  4. Independent origin and restricted distribution of RPGR deletions causing XLPRA.

    PubMed

    Zangerl, Barbara; Johnson, Jennifer L; Acland, Gregory M; Aguirre, Gustavo D

    2007-01-01

    Canine X-linked progressive retinal atrophy (XLPRA) is an inherited blinding disorder caused by mutations in the ORF15 of the RPGR gene and homolog to human retinitis pigmentosa 3 (RP3). The disease is observed in 2 variations, XLPRA1 in Siberian husky and samoyed and XLPRA2 derived from mongrel dogs. A third, neutral, deletion has been described in red wolves. Haplotype analysis of the 633-kbp RP3 interval in 6 different canidae confirmed the same decent for the XLPRA1 mutation in both affected breeds but suggests a recent and independent origin for both forms of XLPRA. The RP3 interval was excluded from causative associations with blindness in the red wolf and akita, a breed closely related to Nordic sled dogs. Overall, these data suggest a limited distribution of the affected haplotypes and indicate that mutations in the ORF15 are likely to be limited to the described dog breeds.

  5. Design and Factory Test of the E /E- Frascati Linear Accelerator for DAFNE

    SciTech Connect

    Anamkath, H.; Lyons, S.; Nett, D.; Treas, P.; Whitham, K.; Zante, T.; Miller, R.; Boni, R.; Hsieh, H.; Sannibale, F.; Vescovi, M.; Vignola, G.; /Frascati

    2011-11-28

    The electron-positron accelerator for the DAFNE project has been built and is in test at Titan Beta in Dublin, CA. This S-Band RF linac system utilizes four 45 MW sledded klystrons and 16-3 m accelerating structures to achieve the required performance. It delivers a 4 ampere electron beam to the positron converter and accelerates the resulting positrons to 550 MeV. The converter design uses a 4.3T pulsed tapered flux compressor along with a pseudo-adiabatic tapered field to a 5 KG solenoid over the first two positron accelerating sections. Quadrupole focusing is used after 100 MeV. The system performance is given in Table 1. This paper briefly describes the design and development of the various subassemblies in this system and gives the initial factory test data.

  6. Measuring aberrations in the rat brain by coherence-gated wavefront sensing using a Linnik interferometer.

    PubMed

    Wang, Jinyu; Léger, Jean-François; Binding, Jonas; Boccara, A Claude; Gigan, Sylvain; Bourdieu, Laurent

    2012-10-01

    Aberrations limit the resolution, signal intensity and achievable imaging depth in microscopy. Coherence-gated wavefront sensing (CGWS) allows the fast measurement of aberrations in scattering samples and therefore the implementation of adaptive corrections. However, CGWS has been demonstrated so far only in weakly scattering samples. We designed a new CGWS scheme based on a Linnik interferometer and a SLED light source, which is able to compensate dispersion automatically and can be implemented on any microscope. In the highly scattering rat brain tissue, where multiply scattered photons falling within the temporal gate of the CGWS can no longer be neglected, we have measured known defocus and spherical aberrations up to a depth of 400 µm.

  7. Angle interferometer cross axis errors

    NASA Astrophysics Data System (ADS)

    Bryan, J. B.; Carter, D. L.; Thompson, S. L.

    1994-01-01

    Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them.

  8. A Preliminary Evaluation of Child Restraints and Anchorage Systems for an Australian Car

    PubMed Central

    Charlton, Judith L.; Fildes, Brian; Laemmle, Ronald; Smith, Stuart; Douglas, Fiona

    2004-01-01

    This study examined the performance of three rear-facing and two forward-facing child restraints (CRS) with three anchorage systems: standard seatbelt, LATCH (flexible) and ISOFIX (rigid). Frontal (64 km/h) and side impact (15 km/h) HyGe sled tests were conducted using a sedan buck. Overall, the preliminary findings suggested superior performance of rigid over seatbelt and flexible anchorages, particularly in side impacts. The results also suggest a need for design improvement for CRS with flexible anchorages to increase stability in side impacts. The findings have important implications for the proposed introduction of changes to Australian Standards for CRS to permit both flexible and rigid systems to coexist with conventional seatbelt anchorage systems. PMID:15319118

  9. GIF Animation of Mode Shapes and Other Data on the Internet

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.

    1998-01-01

    The World Wide Web abounds with animated cartoons and advertisements competing for our attention. Most of these figures are animated Graphics Interchange Format (GIF) files. These files contain a series of ordinary GIF images plus control information, and they provide an exceptionally simple, effective way to animate on the Internet. To date, however, this format has rarely been used for technical data, although there is no inherent reason not to do so. This paper describes a procedure for creating high-resolution animated GIFs of mode shapes and other types of structural dynamics data with readily available software. The paper shows three example applications using recent modal test data and video footage of a high-speed sled run. A fairly detailed summary of the GIF file format is provided in the appendix. All of the animations discussed in the paper are posted on the Internet available through the following address: http://sdb-www.larc.nasa.gov/.

  10. Numerical design and analysis of a compact TE{sub 10} to TE{sub 01} mode transducer

    SciTech Connect

    Tantawi, S.; Ko, K.; Kroll, N.

    1993-04-01

    A high-power low-loss mode transducer design has been proposed to adapt the output of the X-Band klystron, WR90 rectangular waveguide, to the input of the pulse compression system, SLED II, which utilizes overmoded circular waveguides operating in the low-loss TE{sub 01} mode. This device is much more compact than the conventional Marie type mode converters. The device splits the incoming klystron output into two separate rectangular guides that are then fed into a circular guide through a four-slot arrangement. We will use both MAFIA and HFSS to calculate the transmission properties of the three-dimensional structure. We will also determine the extent of mode contamination and compare the numerical results with experiments.

  11. THE MOLECULAR GAS IN LUMINOUS INFRARED GALAXIES. II. EXTREME PHYSICAL CONDITIONS AND THEIR EFFECTS ON THE X{sub co} FACTOR

    SciTech Connect

    Papadopoulos, Padelis P.; Van der Werf, Paul; Xilouris, E.; Isaak, Kate G.; Gao, Yu E-mail: pvdwerf@strw.leidenuniv.nl E-mail: kisaak@rssd.esa.int

    2012-05-20

    In this work, we conclude the analysis of our CO line survey of luminous infrared galaxies (LIRGs: L{sub IR} {approx}> 10{sup 11} L{sub Sun }) in the local universe (Paper I) by focusing on the influence of their average interstellar medium (ISM) properties on the total molecular gas mass estimates via the so-called X{sub co} = M(H{sub 2})/L{sub co,1-0} factor. One-phase radiative transfer models of the global CO spectral line energy distributions (SLEDs) yield an X{sub co} distribution with (X{sub co}) {approx} (0.6 {+-} 0.2) M{sub Sun} (K km s{sup -1} pc{sup 2}){sup -1} over a significant range of average gas densities, temperatures, and dynamic states. The latter emerges as the most important parameter in determining X{sub co}, with unbound states yielding low values and self-gravitating states yielding the highest ones. Nevertheless, in many (U)LIRGs where available higher-J CO lines (J = 3-2, 4-3, and/or J = 6-5) or HCN line data from the literature allow a separate assessment of the gas mass at high densities ({>=}10{sup 4} cm{sup -3}) rather than a simple one-phase analysis, we find that near-Galactic X{sub co} {approx} (3-6) M{sub Sun} (K km s{sup -1} pc{sup 2}){sup -1} values become possible. We further show that in the highly turbulent molecular gas in ULIRGs, a high-density component will be common and can be massive enough for its high X{sub co} to dominate the average value for the entire galaxy. Using solely low-J CO lines to constrain X{sub co} in such environments (as has been the practice up until now) may have thus resulted in systematic underestimates of molecular gas mass in ULIRGs, as such lines are dominated by a warm, diffuse, and unbound gas phase with low X{sub co} but very little mass. Only well-sampled high-J CO SLEDs (J = 3-2 and higher) and/or multi-J observations of heavy rotor molecules (e.g., HCN) can circumvent such a bias, and the latter type of observations may have actually provided early evidence of it in local ULIRGs. The only

  12. Sports Training

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Practitioners of martial arts have long seen a need for a precise method of measuring the power of a karate kick or a boxer's punch in training and competition. Impax sensor is a piezoelectric film less than one thousandth of an inch thick, yet extremely durable. They give out a voltage impulse when struck, the greater the force of impact, the higher the voltage. The impulse is transmitted to a compact electronics package where voltage is translated into a force-pounds reading shown on a digital display. Impax, manufactured by Impulse Technology, Inc. is used by martial arts instructors, practitioners, U.S. Olympic Committee Training Center, football blocking sleds, and boxers as well as police defensive tactics, providing a means of evaluating the performance of recruits.

  13. Polymer Infiltration Studies

    SciTech Connect

    Marchello, J.M.

    1993-06-01

    Significant progress has been made on the preparation of carbon fiber composites using advanced polymer resins during the past three months. Current and ongoing research activities reported herein include: (1) Prepregger Hot Sled Operation; (2) Ribbonizing Powder-Impregnated Towpreg; (3) Textile Composites from Powder-Coated Towpreg: Role of Bulk Factor; and (4) Powder Curtain Prepreg Process. During the coming months research will be directed toward further development of the new powder curtain prepregging method and on ways to customize dry powder towpreg for textile and robotic applications in aircraft part fabrication. Studies of multi-tow powder prepregging and ribbon preparation will be conducted in conjunction with continued development of prepegging technology and the various aspects of composite part fabrication using customized towpreg. Also, work will continue on the analysis of the new solution prepegger.

  14. Polymer Infiltration Studies

    NASA Technical Reports Server (NTRS)

    Marchello, Joseph M.

    1993-01-01

    Significant progress has been made on the preparation of carbon fiber composites using advanced polymer resins during the past three months. Current and ongoing research activities reported herein include: (1) Prepregger Hot Sled Operation; (2) Ribbonizing Powder-Impregnated Towpreg; (3) Textile Composites from Powder-Coated Towpreg: Role of Bulk Factor; and (4) Powder Curtain Prepreg Process. During the coming months research will be directed toward further development of the new powder curtain prepregging method and on ways to customize dry powder towpreg for textile and robotic applications in aircraft part fabrication. Studies of multi-tow powder prepregging and ribbon preparation will be conducted in conjunction with continued development of prepegging technology and the various aspects of composite part fabrication using customized towpreg. Also, work will continue on the analysis of the new solution prepegger.

  15. Comparing Three Methods for Teaching Newton's Second Law

    NASA Astrophysics Data System (ADS)

    Wittmann, Michael C.; Anderson, Mindi Kvaal; Smith, Trevor I.

    2009-11-01

    As a follow-up to a study comparing learning of Newton's Third Law when using three different forms of tutorial instruction, we have compared student learning of Newton's Second Law (NSL) when students use the Tutorials in Introductory Physics, Activity-Based Tutorials, or Open Source Tutorials. We split an algebra-based, life sciences physics course in 3 groups and measured students' pre- and post-instruction scores on the Force and Motion Conceptual Evaluation (FMCE). We look at only the NSL-related clusters of questions on the FMCE to compare students' performance and normalized gains. Students entering the course are not significantly different, and students using the Tutorials in Introductory Physics show the largest normalized gains in answering question on the FMCE correctly. These gains are significant in only one cluster of questions, the Force Sled cluster.

  16. Improved temperature regulation of APS linac RF components.

    SciTech Connect

    Dortwegt, R.

    1998-09-21

    The temperature of the APS S-Band linac's high-power rf components is regulated by water from individual closed-loop deionized (DI) water systems. The rf components are all made of oxygen-free high-conductivity copper and respond quickly to temperature changes. The SLED cavities are especially temperature-sensitive and cause beam energy instabilities when the temperature is not well regulated. Temperature regulation better than {+-} 0.1 F is required to achieve good energy stability. Improvements in the closed-loop water systems have enabled them to achieve a regulation of {+-} 0.05 F over long periods. Regulation philosophy and equipment are discussed and numerical results are presented.

  17. Method for quantitative estimation of position perception using a joystick during linear movement.

    PubMed

    Wada, Y; Tanaka, M; Mori, S; Chen, Y; Sumigama, S; Naito, H; Maeda, M; Yamamoto, M; Watanabe, S; Kajitani, N

    1996-12-01

    We designed a method for quantitatively estimating self-motion perceptions during passive body movement on a sled. The subjects were instructed to tilt a joystick in proportion to perceived displacement from a giving starting position during linear movement with varying displacements of 4 m, 10 m and 16 m induced by constant acceleration of 0.02 g, 0.05 g and 0.08 g along the antero-posterior axis. With this method, we could monitor not only subjective position perceptions but also response latencies for the beginning (RLbgn) and end (RLend) of the linear movement. Perceived body position fitted Stevens' power law, where R=kSn (R is output of the joystick, k is a constant, S is the displacement from the linear movement and n is an exponent). RLbgn decreased as linear acceleration increased. We conclude that this method is useful in analyzing the features and sensitivities of self-motion perceptions during movement.

  18. Fast and accurate read-out of interferometric optical fiber sensors

    NASA Astrophysics Data System (ADS)

    Bartholsen, Ingebrigt; Hjelme, Dag R.

    2016-03-01

    We present results from an evaluation of phase and frequency estimation algorithms for read-out instrumentation of interferometric sensors. Tests on interrogating a micro Fabry-Perot sensor made of semi-spherical stimuli-responsive hydrogel immobilized on a single mode fiber end face, shows that an iterative quadrature demodulation technique (IQDT) implemented on a 32-bit microcontroller unit can achieve an absolute length accuracy of ±50 nm and length change accuracy of ±3 nm using an 80 nm SLED source and a grating spectrometer for interrogation. The mean absolute error for the frequency estimator is a factor 3 larger than the theoretical lower bound for a maximum likelihood estimator. The corresponding factor for the phase estimator is 1.3. The computation time for the IQDT algorithm is reduced by a factor 1000 compared to the full QDT for the same accuracy requirement.

  19. Risk assessment and its application to flight safety analysis

    SciTech Connect

    Keese, D.L.; Barton, W.R.

    1989-12-01

    Potentially hazardous test activities have historically been a part of Sandia National Labs mission to design, develop, and test new weapons systems. These test activities include high speed air drops for parachute development, sled tests for component and system level studies, multiple stage rocket experiments, and artillery firings of various projectiles. Due to the nature of Sandia's test programs, the risk associated with these activities can never be totally eliminated. However, a consistent set of policies should be available to provide guidance into the level of risk that is acceptable in these areas. This report presents a general set of guidelines for addressing safety issues related to rocket flight operations at Sandia National Laboratories. Even though the majority of this report deals primarily with rocket flight safety, these same principles could be applied to other hazardous test activities. The basic concepts of risk analysis have a wide range of applications into many of Sandia's current operations. 14 refs., 1 tab.

  20. Deployment loads data from a free-flight investigation of all flexible parawings having 371.612 sq meters (4000 sq feet) of wing area

    NASA Technical Reports Server (NTRS)

    Croom, D. R.

    1971-01-01

    A free-flight test program to determine the deployment characteristics of all-flexible parawings was conducted. Both single-keel and twin-keel parawings having a wing area of 4000 square feet with a five-stage reefing system were tested by use of a bomb-type instrumented test vehicle. Several twin-keel-parawing tests were also made by using an instrumented controllable sled-type test vehicle. The systems were launched from either a C-130 or a C-119 carrier airplane, and a programer parachute was used to bring the test vehicle to a proper dynamic pressure and near-vertical flight path prior to deployment of the parawing system. The free-flight deployment loads data are presented in the form of time histories of individual suspension-line loads and total loads.

  1. The characteristics of the outdoor school environment associated with physical activity.

    PubMed

    Haug, Ellen; Torsheim, Torbjørn; Sallis, James F; Samdal, Oddrun

    2010-04-01

    The school is an important setting for physical activity. The purpose of the present study was to examine the association between physical environmental characteristics and participation in daily physical activity during school breaks. Data from 130 schools and 16 471 students (Grades 4-10) in Norway were obtained in 2004 through self-administered questionnaires to principals and students. Multilevel logistic regression models revealed that boys at secondary level with a larger number of outdoor facilities at school had 2.69 times [95% confidence interval (CI) = 1.21-5.98] and girls 2.90 times (95% CI = 1.32-6.37) higher odds of being physically active compared with students in schools with fewer facilities. Boys at secondary level with areas for hopscotch/skipping rope had 2.53 times (95% CI = 1.55-4.13), with a soccer field 1.68 times (95% CI = 1.15-2.45), with playground equipment 1.66 times (95% CI = 1.16-2.37) and with a sledding hill 1.70 times (95% CI = 1.23-2.35) higher odds to be physically active compared with students in schools without these facilities. A sledding hill was also associated with girls' physical activity participation in secondary school (odds ratio = 1.58, 95% CI = 1.11-2.24). Outdoor facilities in secondary schools are associated with students' daily physical activity participation during school breaks. Therefore, improving the outdoor environment should be considered in physical activity promotion school programs in secondary schools.

  2. Predicting the intensity mapping signal for multi-J CO lines

    SciTech Connect

    Mashian, Natalie; Loeb, Abraham; Sternberg, Amiel E-mail: amiel@wise.tau.ac.il

    2015-11-01

    We present a novel approach to estimating the intensity mapping signal of any CO rotational line emitted during the Epoch of Reionization (EoR). Our approach is based on large velocity gradient (LVG) modeling, a radiative transfer modeling technique that generates the full CO spectral line energy distribution (SLED) for a specified gas kinetic temperature, volume density, velocity gradient, molecular abundance, and column density. These parameters, which drive the physics of CO transitions and ultimately dictate the shape and amplitude of the CO SLED, can be linked to the global properties of the host galaxy, mainly the star formation rate (SFR) and the SFR surface density. By further employing an empirically derived SFR−M relation for high redshift galaxies, we can express the LVG parameters, and thus the specific intensity of any CO rotational transition, as functions of the host halo mass M and redshift z. Integrating over the range of halo masses expected to host CO-luminous galaxies, we predict a mean CO(1-0) brightness temperature ranging from ∼ 0.6 μK at z = 6 to ∼ 0.03 μK at z = 10 with brightness temperature fluctuations of Δ{sub CO}{sup 2} ∼ 0.1 and 0.005 μK respectively, at k = 0.1 Mpc{sup −1}. In this model, the CO emission signal remains strong for higher rotational levels at z = 6, with ( T{sub CO} ) ∼ 0.3 and 0.05 μK for the CO J = 6arrow5 and CO J = 10arrow9 transitions respectively. Including the effects of CO photodissociation in these molecular clouds, especially at low metallicities, results in the overall reduction in the amplitude of the CO signal, with the low- and high-J lines weakening by 2–20% and 10–45%, respectively, over the redshift range 4 < z < 10.

  3. Decisions in motion: vestibular contributions to saccadic target selection.

    PubMed

    Rincon-Gonzalez, L; Selen, L P J; Halfwerk, K; Koppen, M; Corneil, B D; Medendorp, W P

    2016-09-01

    The natural world continuously presents us with many opportunities for action, and thus a process of target selection must precede action execution. While there has been considerable progress in understanding target selection in stationary environments, little is known about target selection when we are in motion. Here we investigated the effect of self-motion signals on saccadic target selection in a dynamic environment. Human subjects were sinusoidally translated (f = 0.6 Hz, 30-cm peak-to-peak displacement) along an interaural axis with a vestibular sled. During the motion two visual targets were presented asynchronously but equidistantly on either side of fixation. Subjects had to look at one of these targets as quickly as possible. With an adaptive approach, the time delay between these targets was adjusted until the subject selected both targets equally often. We determined this balanced time delay for different phases of the motion in order to distinguish the effects of body acceleration and velocity on saccadic target selection. Results show that acceleration (or position, as these are indistinguishable during sinusoidal motion), but not velocity, affects target selection for saccades. Subjects preferred to look at targets in the direction of the acceleration-the leftward target was preferred when the sled accelerated to the left, and vice versa. Saccadic reaction times mimicked this selection bias by being reliably shorter to targets in the direction of acceleration. Our results provide evidence that saccade target selection mechanisms are modulated by self-motion signals, which could be derived directly from the otolith system.

  4. Experimental Study of the Richtmyer-Meshkov Instability of Incompressible Fluids

    NASA Technical Reports Server (NTRS)

    Niederhaus, Charles; Jacobs, Jeffrey W.

    2002-01-01

    The Richtmyer-Meshkov instability of a low Atwood number, miscible, two-liquid system is investigated experimentally. The initially stratified fluids are contained within a rectangular tank mounted to a sled that rides on a vertical set of rails. The instability is generated by dropping the sled onto a coil spring, producing a nearly impulsive upward acceleration. The subsequent freefall that occurs as the container travels upward and then downward on the rails allows the instability to evolve in the absence of gravity. The interface separating the two liquids initially has a well-defined, sinusoidal perturbation that quickly inverts and then grows in amplitude after undergoing the impulsive acceleration. Disturbance amplitudes are measured and compared to theoretical predictions. Linear stability theory gives excellent agreement with the measured initial growth rate, a(sub 0), for single-mode perturbations with the predicted amplitudes differing by less than 10% from experimental measurements up to a nondimensional time ka(sub 0)t = 0.7, where k is the wavenumber. Linear stability theory also provides excellent agreement for the individual mode amplitudes of multi-mode initial perturbations up until the interface becomes multi-valued. Comparison with previously published weakly nonlinear single-mode models shows good agreement up to ka(sub 0)t = 3, while published nonlinear single-mode models provide good agreement up to ka(sub 0)t = 30. The effects of Reynolds number on the vortex core evolution and overall growth rate of the interface are also investigated. Measurements of the overall amplitude are found to be unaffected by the Reynolds number for the range of values studied here. However, experiments carried out at lower values of Reynolds numbers were found to have decreased vortex core rotation rates. In addition, an instability in the vortex cores is observed.

  5. Self-tuning at large (distances): 4D description of runaway dilaton capture

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; Diener, Ross; Williams, M.

    2015-10-01

    We complete here a three-part study (see also arXiv:1506.08095 and arXiv:1508.00856) of how codimension-two objects back-react gravitationally with their environment, with particular interest in situations where the transverse `bulk' is stabilized by the interplay between gravity and flux-quantization in a dilaton-Maxwell-Einstein system such as commonly appears in higher-dimensional supergravity and is used in the Supersymmetric Large Extra Dimensions (SLED) program. Such systems enjoy a classical flat direction that can be lifted by interactions with the branes, giving a mass to the would-be modulus that is smaller than the KK scale. We construct the effective low-energy 4D description appropriate below the KK scale once the transverse extra dimensions are integrated out, and show that it reproduces the predictions of the full UV theory for how the vacuum energy and modulus mass depend on the properties of the branes and stabilizing fluxes. In particular we show how this 4D theory learns the news of flux quantization through the existence of a space-filling four-form potential that descends from the higher-dimensional Maxwell field. We find a scalar potential consistent with general constraints, like the runaway dictated by Weinberg's theorem. We show how scale-breaking brane interactions can give this potential minima for which the extra-dimensional size, ℓ, is exponentially large relative to underlying physics scales, r B , with ℓ 2 = r B 2 e - φ where - φ ≫ 1 can be arranged with a small hierarchy between fundamental parameters. We identify circumstances where the potential at the minimum can (but need not) be parametrically suppressed relative to the tensions of the branes, provide a preliminary discussion of the robustness of these results to quantum corrections, and discuss the relation between what we find and earlier papers in the SLED program.

  6. Parachute Compartment Drop Test Vehicle for Testing the Crew Exploration Vehicle's Parachute Assembly System

    NASA Technical Reports Server (NTRS)

    Lubey, Daniel P.; Thiele, Sara R.; Gruseck, Madelyn L.; Evans, Carol T.

    2010-01-01

    Though getting astronauts safely into orbit and beyond has long been one of NASA?s chief goals, their safe return has always been equally as important. The Crew Exploration Vehicle?s (CEV) Parachute Assembly System (CPAS) is designed to safely return astronauts to Earth on the next-generation manned spacecraft Orion. As one means for validating this system?s requirements and testing its functionality, a test article known as the Parachute Compartment Drop Test Vehicle (PC-DTV) will carry a fully-loaded yet truncated CPAS Parachute Compartment (PC) in a series of drop tests. Two aerodynamic profiles for the PC-DTV currently exist, though both share the same interior structure, and both have an Orion-representative weight of 20,800 lbf. Two extraction methods have been developed as well. The first (Cradle Monorail System 2 - CMS2) uses a sliding rail technique to release the PC-DTV midair, and the second (Modified DTV Sled; MDS) features a much less constrained separation method though slightly more complex. The decision as to which aerodynamic profile and extraction method to use is still not finalized. Additional CFD and stress analysis must be undertaken in order to determine the more desirable options, though at present the "boat tail" profile and the CMS2 extraction method seem to be the favored options in their respective categories. Fabrication of the PC-DTV and the selected extraction sled is set to begin in early October 2010 with an anticipated first drop test in mid-March 2011.

  7. Head stabilization shows visual and inertial dependence during passive stimulation: implications for virtual rehabilitation.

    PubMed

    Wright, W Geoffrey; Agah, Mobin Rastgar; Darvish, Kurosh; Keshner, Emily A

    2013-03-01

    Sensorimotor coordination relies on the fine calibration and integration of visual, vestibular, and somatosensory input. Using virtual environments (VE) allows for the dissociation of visual and inertial inputs to manipulate human behavioral outputs. Our goal was to employ VE technology in a novel manner to investigate how head stabilization is affected by spatiotemporal properties of dynamic visual input when combined with passive motion on a linear sled. Healthy adults (n = 12) wore a head-mounted display during naso-occipital sinusoidal horizontal whole body translations while seated. Subjects were secured in a seat with a five-point harness, with the head free to move. Frequency and amplitude of sinusoidal input (i.e., inertial conditions) were set to create overlapping conditions of maximum acceleration (amax) or velocity (vmax). Four inertial conditions were combined with four visual conditions (VIS). VIS were created so that direction of optic flow either matched direction of passive motion or did not. The effect of near and far fixation distance within the VE was also tested. Head kinematics were collected with a three-axis gyro. Head stability showed a complex interaction dependent on changes in weighting of visual and inertial inputs that changed with the sled driving frequency. Inertial condition affected amplitude (p < 0.0000) and phase (p < 0.0000) of head pitch angular velocity. In the absence of visual input, head pitch velocity amplitude increased (p < 0.01). An interaction effect between inertial and VIS conditions on head yaw occurred in SW (p < 0.05). There was also a significant interaction of depth of field and inertial condition on amplitude (p < 0.001) and phase (p < 0.05) of head yaw velocity in SW, especially during high vmax conditions. We conclude visual flow can organize lateral cervical responses despite being discordant with inertial input. When using VE for rehabilitation, possible unintended, involuntary or reflexive motor responses

  8. Field Micrometeorological Measurements, Process-Level Studies and Modeling of Methane and Carbon Dioxide Fluxes in a Boreal Wetland Ecosystem

    NASA Technical Reports Server (NTRS)

    Verma, S. B.; Arkebauer, T. J.; Ullman, F. G.; Valentine, D. W.; Parton, W. J.; Schimel, D. S.

    1998-01-01

    The main instrumentation platform consisted of eddy correlation sensors mounted on a scaffold tower at a height of 4.2 m above the peat surface. The sensors were attached to a boom assembly which could be rotated into the prevailing winds. The boom assembly was mounted on a movable sled which, when extended, allowed sensors to be up to 2 m away from the scaffolding structure to minimize flow distortion. When retracted, the sensors could easily be installed, serviced or rotated. An electronic level with linear actuators allowed the sensors to be remotely levelled once the sled was extended. Two instrument arrays were installed. A primary (fast-response) array consisted of a three-dimensional sonic anemometer, a methane sensor (tunable diode laser spectrometer), a carbon dioxide/water vapor sensor, a fine wire thermocouple and a backup one-dimensional sonic anemometer. The secondary array consisted of a one-dimensional sonic anemometer, a fine wire thermocouple and a Krypton hygrometer. Descriptions of these sensors may be found in other reports (e.g., Verma; Suyker and Verma). Slow-response sensors provided supporting measurements including mean air temperature and humidity, mean horizontal windspeed and direction, incoming and reflected solar radiation, net radiation, incoming and reflected photosynthetically active radiation (PAR), soil heat flux, peat temperature, water-table elevation and precipitation. A data acquisition system (consisting of an IBM compatible microcomputer, amplifiers and a 16 bit analog-to-digital converter), housed in a small trailer, was used to record the fast response signals. These signals were low-pass filtered (using 8-pole Butterworth active filters with a 12.5 Hz cutoff frequency) and sampled at 25 Hz. Slow-response signals were sampled every 5 s using a network of CR21X (Campbell Scientific, Inc., Logan Utah) data loggers installed in the fen. All signals were averaged over 30-minute periods (runs).

  9. The influence of seatback characteristics on cervical injury risk in severe rear impacts.

    PubMed

    Burnett, Roger; Carter, Jarrod; Roberts, Verne; Myers, Barry

    2004-07-01

    The determination of the optimum seatback characteristics for the mitigation of serious and catastrophic neck injury during high-speed rear-end collisions remains a topic of continued investigation. Despite a number of prior research efforts, both field data and sled test studies have yet to define a single optimal seatback performance criterion. Further, recent developments in seatbacks have introduced new designs into the field that have not been compared to more traditional designs. Analysis of NASS data from 1980 to 1999 demonstrated that at changes in velocity (DeltaV) above 40 kph, rear-end collisions have a dramatically lower risk for catastrophic injury than frontal, near-side or far-side impacts. Unfortunately, owing to the small penetration of newer seatback designs in the automotive fleet, it is not possible to examine the influence of seatback design parameters on serious neck injury using these data alone. Accordingly, seven rear impact HYGE sled tests were conducted using a wide range of seat designs. Upper and lower neck load cells were used to measure neck forces and moments in restrained 50th male Hybrid III anthropomorphic test devices (ATD). Additionally, the neck injury criteria (Nij) was computed. Unlike prior studies that have examined the standard seated ATD or the dramatically out-of-position ATD, these tests were conducted using an ATD seated in non-standard but typical driving position. The results of this study indicate that several descriptions of seatback behavior, such as quasi-static ultimate force are poor predictors of ATD neck loading. It also suggests that, for the severe crash studied, an optimum range of seatback stiffness exists, which appears to be in the mid-range of seatback stiffnesses available in current production vehicles. These data continue to illustrate the complex relationship of seatback design parameters to neck injury risk.

  10. Online X-ray Fluorescence (XRF) Analysis of Heavy Metals in Pulverized Coal on a Conveyor Belt.

    PubMed

    Yan, Zhang; XinLei, Zhang; WenBao, Jia; Qing, Shan; YongSheng, Ling; DaQian, Hei; Da, Chen

    2016-02-01

    Heavy metals in haze episode will continue to threaten the quality of public health around the world. In order to decrease the emission of heavy metals produced from coal burning, an online X-ray fluorescence (XRF) analyzer system, consisting of an XRF analyzer with data acquisition software and a laser rangefinder, was developed to carry out the measurement of heavy metals in pulverized coal. The XRF analyzer was mounted on a sled, which can effectively smooth the surface of pulverized coal and reduce the impact of surface roughness during online measurement. The laser rangefinder was mounted over the sled for measuring the distance between a pulverized coal sample and the analyzer. Several heavy metals and other elements in pulverized coal were online measured by the XRF analyzer directly above a conveyor belt. The limits of detection for Hg, Pb, Cr, Ti, Fe, and Ca by the analyzer were 44 ± 2, 34 ± 2, 17 ± 3, 41 ± 4, 19 ± 3, and 65 ± 2 mg·kg(-1), respectively. The relative standard deviation (%RSD) for the elements mentioned was less than 7.74%. By comparison with the results by inductively-coupled plasma mass spectrometry (ICP-MS), relative deviation (%D) of the online XRF analyzer was less than 10% for Cr, Ti, and Ca, in the range of 0.8-24.26% for Fe, and greater than 20% for Hg and Pb.

  11. Multiple case studies of STEM teachers' orientations to science teaching through engineering design

    NASA Astrophysics Data System (ADS)

    Rupp, Madeline

    The following master's thesis is composed of two manuscripts describing STEM teachers' orientations to science teaching through engineering within the context of the Science Learning through Engineering Design (SLED) partnership. The framework guiding both studies was science teaching orientations, a component of pedagogical content knowledge. Data were collected via semi-structured interviews, multi-day classroom observations, pre- and post-observation interviews, implementation plans, and written reflections. Data sources were analyzed to generate two orientations to science teaching through engineering design for each participant. The first manuscript illustrates a single case study conducted with a sixth grade STEM teacher. Results of this study revealed a detailed picture of the teacher's goals, practices, assessments, and general views when teaching science through engineering design. Common themes across the teacher's instruction were used to characterize her orientations to science teaching through engineering design. Overall, the teacher's orientations showed a shift in her practice from didactic to student-centered methods of teaching as a result of integrating engineering design-based curriculum. The second manuscript describes a comparative case study of two sixth grade SLED participants. Results of this study revealed more complex and diverse relationships between the teachers' orientations to teaching science through engineering design and their instruction. Participants' orientations served as filters for instruction, guided by their divergent purposes for science teaching. Furthermore, their orientations and resulting implementation were developed from knowledge gained in teacher education, implying that teacher educators and researchers can use this framework to learn more about how teachers' knowledge is used to integrate engineering and science practices in the K-12 classroom.

  12. Electromyography of superficial and deep neck muscles during isometric, voluntary, and reflex contractions.

    PubMed

    Siegmund, Gunter P; Blouin, Jean-Sébastien; Brault, John R; Hedenstierna, Sofia; Inglis, J Timothy

    2007-02-01

    Increasingly complex models of the neck neuromusculature need detailed muscle and kinematic data for proper validation. The goal of this study was to measure the electromyographic activity of superficial and deep neck muscles during tasks involving isometric, voluntary, and reflexively evoked contractions of the neck muscles. Three male subjects (28-41 years) had electromyographic (EMG) fine wires inserted into the left sternocleidomastoid, levator scapulae, trapezius, splenius capitis, semispinalis capitis, semispinalis cervicis, and multifidus muscles. Surface electrodes were placed over the left sternohyoid muscle. Subjects then performed: (i) maximal voluntary contractions (MVCs) in the eight directions (45 deg intervals) from the neutral posture; (ii) 50 N isometric contractions with a slow sweep of the force direction through 720 deg; (iii) voluntary oscillatory head movements in flexion and extension; and (iv) initially relaxed reflex muscle activations to a forward acceleration while seated on a sled. Isometric contractions were performed against an overhead load cell and movement dynamics were measured using six-axis accelerometry on the head and torso. In all three subjects, the two anterior neck muscles had similar preferred activation directions and acted synergistically in both dynamic tasks. With the exception of splenius capitis, the posterior and posterolateral neck muscles also showed consistent activation directions and acted synergistically during the voluntary motions, but not during the sled perturbations. These findings suggest that the common numerical-modeling assumption that all anterior muscles act synergistically as flexors is reasonable, but that the related assumption that all posterior muscles act synergistically as extensors is not. Despite the small number of subjects, the data presented here can be used to inform and validate a neck model at three levels of increasing neuromuscular-kinematic complexity: muscles generating forces

  13. Crew Exploration Vehicle (CEV) (Orion) Occupant Protection. [Appendices Part 2

    NASA Technical Reports Server (NTRS)

    Currie-Gregg, Nancy J.; Gernhardt, Michael L.; Lawrence, Charles; Somers, Jeffrey T.

    2016-01-01

    The purpose of this study was to determine the similarity between the response of the THUMS model and the Hybrid III Anthropometric Test Device (ATD) given existing Wright-Patterson (WP) sled tests. There were four tests selected for this comparison with frontal, spinal, rear, and lateral loading. The THUMS was placed in a sled configuration that replicated the WP configuration and the recorded seat acceleration for each test was applied to model seat. Once the modeling simulations were complete, they were compared to the WP results using two methods. The first was a visual inspection of the sled test videos compared to the THUMS d3plot files. This comparison resulted in an assessment of the overall kinematics of the two results. The other comparison was a comparison of the plotted data recorded for both tests. The metrics selected for comparison were seat acceleration, belt forces, head acceleration and chest acceleration. These metrics were recorded in all WP tests and were outputs of the THUMS model. Once the comparison of the THUMS to the WP tests was complete, the THUMS model output was also examined for possible injuries in these scenarios. These outputs included metrics for injury risk to the head, neck, thorax, lumbar spine and lower extremities. The metrics to evaluate head response were peak head acceleration, HIC15, and HIC36. For the neck, N (sub ij) was calculated. The thorax response was evaluated with peak chest acceleration, the Combined Thoracic Index (CTI), sternal deflection, chest deflection, and chest acceleration- 3 ms clip. The lumbar spine response was evaluated with lumbar spine force. Finally the lower extremity response was evaluated by femur and tibia force. The results of the simulation comparisons indicate the THUMS model had a similar response to the Hybrid III dummy given the same input. The primary difference seen between the two was a more flexible response of the THUMS compared to the Hybrid III. This flexibility was most

  14. CO SPECTRAL LINE ENERGY DISTRIBUTIONS OF INFRARED-LUMINOUS GALAXIES AND ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Papadopoulos, Padeli P.; Van der Werf, Paul; Isaak, Kate; Xilouris, Emmanuel M. E-mail: pvdwerf@strw.leidenuniv.n E-mail: xilouris@astro.noa.g

    2010-06-01

    We report on new sensitive CO J = 6-5 line observations of several luminous infrared galaxies (LIRGs; L {sub IR}(8-1000 {mu}m) {approx}> 10{sup 11} L {sub sun}), 36% (8/22) of them ultraluminous infrared galaxies (ULIRGs) (L {sub IR}>10{sup 12} L {sub sun}), and two powerful local active galactic nuclei (AGNs)-the optically luminous QSO PG 1119+120 and the powerful radio galaxy 3C 293-using the James Clerk Maxwell Telescope on Mauna Kea in Hawaii. We combine these observations with existing low-J CO data and dust emission spectral energy distributions in the far-infrared-submillimeter from the literature to constrain the properties of the star-forming interstellar medium (ISM) in these systems. We then build the first local CO spectral line energy distributions (SLEDs) for the global molecular gas reservoirs that reach up to high J-levels. These CO SLEDs are neither biased by strong lensing (which affects many of those constructed for high-redshift galaxies), nor suffer from undersampling of CO-bright regions (as most current high-J CO observations of nearby extended systems do). We find: (1) a significant influence of dust optical depths on the high-J CO lines, suppressing the J = 6-5 line emission in some of the most IR-luminous LIRGs, (2) low global CO line excitation possible even in vigorously star-forming systems, (3) the first case of a shock-powered high-excitation CO SLED in the radio galaxy 3C 293 where a powerful jet-ISM interaction occurs, and (4) unusually highly excitated gas in the optically powerful QSO PG 1119+120. In Arp 220 and possibly other (U)LIRGs very faint CO J = 6-5 lines can be attributed to significant dust optical depths at short submillimeter wavelengths immersing those lines in a strong dust continuum, and also causing the C{sup +} line luminosity deficit often observed in such extreme starbursts. Re-analysis of the CO line ratios available for submillimeter galaxies suggests that similar dust opacities also may be present in these

  15. Observing Radiative Properties of a Thinner, Seasonal Arctic Ice Pack

    NASA Astrophysics Data System (ADS)

    Hudson, S. R.; Nicolaus, M.; Granskog, M.; Gerland, S.; Wang, C.

    2011-12-01

    variability. For this, we have developed a radiation sled for measuring the full radiation budget of sea ice at a grid of locations to observe the variability within an area similar to a satellite pixel or model grid cell. Based on a modified dog sled, it carries upward and downward looking longwave and shortwave broadband radiometers, a spectral radiometer (350 to 2500 nm) for measuring spectral albedo, cameras to record surface and ground conditions at each measurement site, a thermometer, hygrometer, and GPS. Small enough to be deployed from a ship at short ice stations, it can also be used at longer stations to observe the effect of the spatial variability on the temporal variability. When combined with measurements or estimates of the sensible and latent heat fluxes, a full picture of the large-scale energy budget and its small-scale variations is obtained, valuable insight for parameterization and remote sensing product development. Surface profiles with the sled can be complemented by under-ice profiles made with a spectral radiometer mounted on an ROV or carried by a diver, providing a measure of the spatial variability of the partitioning of the absorbed solar energy into the ice and water.

  16. The Radiation Budget of Sea Ice during the Springtime Melt

    NASA Astrophysics Data System (ADS)

    Hudson, S. R.; Granskog, M.; Elder, B. C.; Perovich, D. K.; Petrich, C.; Nicolaus, M.

    2011-12-01

    The energy budget of sea ice in the melt season has significant spatial variability at scales much smaller than a model cell or satellite pixel. This variability results primarily from albedo variation caused by different surface characteristics such as melt ponds of varying depth, snow of varying thickness, and sediment content within the snow, ice, or surface water. There may also be variation in the longwave energy emitted by the surface, mostly resulting from temperature variations. Understanding this variability and how it affects the progress of the melt is necessary for improving energy-budget parameterizations in models or retrievals from satellite sensors. To gain a better understanding of this variability, we have developed a radiation sled that quickly measures the upwelling and downwelling broadband longwave and shortwave radiation, along with the spectral albedo. In addition, it photographs the sky and surface at the time of the measurement, measures the surface temperature with a narrowband infrared thermometer, and records the measurement location and the air temperature and humidity. The sled is set up to allow many measurements in an area to be made during a short period by one or two people. From this we can see the large scale effect of small scale variations in the surface energy budget. This sled was deployed for the first time during the first two weeks of June this year. Data were collected every 5 m along a 200-m line located on fast ice about 3 km southwest of Point Barrow, Alaska. Observations were made around local noon each day from 5 to 13 June, when the progression of the melt forced us to bring the instruments back to land. During most of the observation period, we had refreezing of melt ponds that were prevalent at the start. Midway through, there was some light snowfall, before melt resumed on the last days. The line included a variety of surfaces, including bare ice with a scattering layer, melt ponds of varying depths with a

  17. The Radiation Budget of Sea Ice during the Springtime Melt

    NASA Astrophysics Data System (ADS)

    Hudson, S.; Granskog, M. A.; Elder, B. C.; Perovich, D. K.; Petrich, C.; Nicolaus, M.

    2012-04-01

    The energy budget of sea ice in the melt season has significant spatial variability at scales much smaller than a model cell or satellite pixel. This variability results primarily from albedo variation caused by different surface characteristics such as melt ponds of varying depth, snow of varying thickness, and sediment content within the snow, ice, or surface water. There may also be variation in the longwave energy emitted by the surface, mostly resulting from temperature variations. Understanding this variability and how it affects the progress of the melt is necessary for improving energy-budget parameterizations in models or retrievals from satellite sensors. To gain a better understanding of this variability, we have developed a radiation sled that quickly measures the upwelling and downwelling broadband longwave and shortwave radiation, along with the spectral albedo. In addition, it photographs the sky and surface at the time of the measurement, measures the surface temperature with a narrowband infrared thermometer, and records the measurement location and the air temperature and humidity. The sled is set up to allow many measurements in an area to be made during a short period by one or two people. From this we can see the large scale effect of small scale variations in the surface energy budget. This sled was deployed for the first time during the first two weeks of June 2011. Data were collected every 5 m along a 200-m line located on fast ice about 3 km southwest of Point Barrow, Alaska. Observations were made around local noon each day from 5 to 13 June, when the progression of the melt forced us to bring the instruments back to land. During most of the observation period, we had refreezing of melt ponds that were prevalent at the start. Midway through, there was some light snowfall, before melt resumed on the last days. The line included a variety of surfaces, including bare ice with a scattering layer, melt ponds of varying depths with a refrozen

  18. Radiative and mechanical feedback into the molecular gas in the Large Magellanic Cloud. I. N159W

    NASA Astrophysics Data System (ADS)

    Lee, M.-Y.; Madden, S. C.; Lebouteiller, V.; Gusdorf, A.; Godard, B.; Wu, R.; Galametz, M.; Cormier, D.; Le Petit, F.; Roueff, E.; Bron, E.; Carlson, L.; Chevance, M.; Fukui, Y.; Galliano, F.; Hony, S.; Hughes, A.; Indebetouw, R.; Israel, F. P.; Kawamura, A.; Le Bourlot, J.; Lesaffre, P.; Meixner, M.; Muller, E.; Nayak, O.; Onishi, T.; Roman-Duval, J.; Sewiło, M.

    2016-12-01

    We present Herschel SPIRE Fourier Transform Spectrometer (FTS) observations of N159W, an active star-forming region in the Large Magellanic Cloud (LMC). In our observations, a number of far-infrared cooling lines, including carbon monoxide (CO) J = 4 → 3 to J = 12 → 11, [CI] 609 μm and 370 μm, and [NII] 205 μm, are clearly detected. With an aim of investigating the physical conditions and excitation processes of molecular gas, we first construct CO spectral line energy distributions (SLEDs) on 10 pc scales by combining the FTS CO transitions with ground-based low-J CO data and analyze the observed CO SLEDs using non-LTE (local thermodynamic equilibrium) radiative transfer models. We find that the CO-traced molecular gas in N159W is warm (kinetic temperature of 153-754 K) and moderately dense (H2 number density of (1.1-4.5) × 103 cm-3). To assess the impact of the energetic processes in the interstellar medium on the physical conditions of the CO-emitting gas, we then compare the observed CO line intensities with the models of photodissociation regions (PDRs) and shocks. We first constrain the properties of PDRs by modeling Herschel observations of [OI] 145 μm, [CII] 158 μm, and [CI] 370 μm fine-structure lines and find that the constrained PDR components emit very weak CO emission. X-rays and cosmic-rays are also found to provide a negligible contribution to theCO emission, essentially ruling out ionizing sources (ultraviolet photons, X-rays, and cosmic-rays) as the dominant heating source for CO in N159W. On the other hand, mechanical heating by low-velocity C-type shocks with 10 km s-1 appears sufficient enough to reproduce the observed warm CO. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.The final reduced Herschel data (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or

  19. Comparison of PMHS, WorldSID, and THOR-NT responses in simulated far side impact.

    PubMed

    Pintar, Frank A; Yoganandan, Narayan; Stemper, Brian D; Bostrom, Ola; Rouhana, Stephen W; Digges, Kennerly H; Fildes, Brian N

    2007-10-01

    Injury to the far side occupant has been demonstrated as a significant portion of the total trauma in side impacts. The objective of the study was to determine the response of PMHS in far side impact configurations, with and without generic countermeasures, and compare responses to the WorldSID and THOR dummies. A far side impact buck was designed for a sled test system that included a center console and three-point belt system. The buck allowed for additional options of generic countermeasures including shoulder or thorax plates or an inboard shoulder belt. The entire buck could be mounted on the sled in either a 90-degree (3-o'clock PDOF) or a 60-degree (2-o'clock PDOF) orientation. A total of 18 tests on six PMHS were done to characterize the far side impact environment at both low (11 km/h) and high (30 km/h) velocities. WorldSID and THOR-NT tests were completed in the same configurations to conduct matched-pair comparisons. For high-speed tests, center console pelvic forces ranged from 3 to 5 kN; thorax or shoulder plate forces (when present) ranged from 3 to 4 kN. Shoulder belt forces were highly dependent on the presence of a thorax or shoulder restraint; without alternate restraint, both inboard and outboard shoulder belt forces were approximately 3 kN. Both dummies had positive and negative biofidelity outcomes. For example, the THOR shoulder against a side restraint produced much higher forces than the PMHS or WorldSID; the WorldSID produced greater pelvic loads in the presence of a shoulder plate than the PMHS or THOR. Both dummies provided good measures of head excursion compared to PMHS across most configurations. Both dummies had difficulty measuring appropriate chest deformations due to belt loading because of measurement device locations. Considerations for countermeasure design should account for the potential for increased injuries to other body regions. For example, in the PMHS tests, a high inboard shoulder belt configuration produced carotid

  20. Thoracic response of belted PMHS, the Hybrid III, and the THOR-NT mid-sized male surrogates in low speed, frontal crashes.

    PubMed

    Forman, Jason; Lessley, David; Shaw, C Greg; Evans, Jay; Kent, Richard; Rouhana, Stephen W; Prasad, Priya

    2006-11-01

    Injury to the thorax is the predominant cause of fatalities in crash-involved automobile occupants over the age of 65, and many elderly-occupant automobile fatalities occur in crashes below compliance or consumer information test speeds. As the average age of the automotive population increases, thoracic injury prevention in lower severity crashes will play an increasingly important role in automobile safety. This study presents the results of a series of sled tests to investigate the thoracic deformation, kinematic, and injury responses of belted post mortem human surrogates (PMHS, average age 44 years) and frontal anthropomorphic test devices (ATDs) in low-speed frontal crashes. Nine 29 km/h (three PMHS, three Hybrid III 50th% male ATD, three THOR-NT ATD) and three 38 km/h (one PMHS, two Hybrid III) frontal sled tests were performed to simulate an occupant seated in the right font passenger seat of a mid-sized sedan restrained with a standard (not force-limited) 3-point seatbelt. All occupants were instrumented to record deformation contours and accelerations of the thorax at multiple locations. The ATD subjects were also instrumented to record the internal deformation of the thorax via multi-point tracking systems. For the 29 km/h tests, PMHS maximum chest deflections ranged from 10% to 19% of the undeformed chest depth, and peak mid-spine accelerations ranged from 21 to 24 g. The average peak internal mid-sternal (sternum slider) deflections for the Hybrid III were 23 mm (29 km/h tests) and 30 mm (38 km/h tests). The average maximum Hybrid III sternal deflection of 23 mm measured in the 29 km/h tests corresponds to an AIS 3+ thoracic injury risk of 14% or greater for people 70 years and older. This result suggests that three-point belted elderly occupants without shoulder-belt force limiters could experience non-trivial thoracic injuries in frontal crashes that are below NHTSA's compliance and/or consumer information test severities.

  1. The limits of endurance exercise.

    PubMed

    Noakes, Timothy David

    2006-09-01

    A skeletal design which favours running and walking, including the greatest ratio of leg length to body weight of any mammal; the ability to sweat and so to exercise vigorously in the heat; and greater endurance than all land mammals other than the Alaskan Husky, indicates that humans evolved as endurance animals. The development of tools to accurately measure time and distance in the nineteenth century inspired some humans to define the limits of this special capacity. Beginning with Six-Day Professional Pedestrian Races in London and New York in the 1880s, followed a decade later by Six-Day Professional Cycling Races - the immediate precursor of the first six-day Tour de France Cycliste race in 1903, which itself inspired the 1928 and 1929 4,960 km "Bunion Derbies" between Los Angeles and New York across the breadth of the United States of America - established those unique sporting events that continue to challenge the modern limits of human endurance. But an analysis of the total energy expenditure achieved by athletes competing in those events establishes that none approaches those reached by another group - the explorers of the heroic age of polar exploration in the early twentieth century. Thus the greatest recorded human endurance performances occurred during the Antarctic sledding expeditions led by Robert Scott in 1911/12 and Ernest Shackleton in 1914/16. By man-hauling sleds for 10 hours daily for approximately 159 and 160 consecutive days respectively, members of those expeditions would have expended close to a total of 1,000,000 kcal. By comparison completing a Six-Day Pedestrian event (55,000 kcal) or the Tour de France (168,000 kcal), or cycling (180,000 kcal) or running (340,000 kcal) across America, requires a considerably smaller total energy expenditure. Thus the limits of human endurance were set at the start of the twentieth century and have not recently been approached. Given good health and an adequate food supply to prevent starvation and

  2. Novel laser approach for remote sensing of atmospheric CO2 column

    NASA Astrophysics Data System (ADS)

    Georgieva, E.; Wilson, E.; Heaps, W. S.

    2008-08-01

    We present preliminary experimental results, sensitivity measurements and discuss our new CO2 lidar system under development. The system is employing an erbium-doped fiber amplifier (EDFA), superluminescent light emitting diode (SLED) as a source and our previously developed Fabry-Perot interferometer subsystem as a detector part. Global measurement of carbon dioxide column with the aim of discovering and quantifying unknown sources and sinks has been a high priority for the last decade. The goal of Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission is to significantly enhance the understanding of the role of CO2 in the global carbon cycle. The National Academy of Sciences recommended in its decadal survey that NASA put in orbit a CO2 lidar to satisfy this long standing need. Existing passive sensors suffer from two shortcomings. Their measurement precision can be compromised by the path length uncertainties arising from scattering within the atmosphere. Also passive sensors using sunlight cannot observe the column at night. Both of these difficulties can be ameliorated by lidar techniques. Lidar systems present their own set of problems however. Temperature changes in the atmosphere alter the cross section for individual CO2 absorption features while the different atmospheric pressures encountered passing through the atmosphere broaden the absorption lines. Currently proposed lidars require multiple lasers operating at multiple wavelengths simultaneously in order to untangle these effects. Our current goal is to develop an ultra precise, inexpensive new lidar system for precise column measurements of CO2 changes in the lower atmosphere that uses a Fabry-Perot interferometer based system as the detector portion of the instrument and replaces the narrow band laser commonly used in lidars with the newly available high power SLED as the source. This approach reduces the number of individual lasers used in the system from three or more to

  3. Study of the suit inflation effect on crew safety during landing using a full-pressure IVA suit for new-generation reentry space vehicles

    NASA Astrophysics Data System (ADS)

    Wataru, Suzuki

    Recently, manned space capsules have been recognized as beneficial and reasonable human space vehicles again. The Dragon capsule already achieved several significant successes. The Orion capsule is going to be sent to a high-apogee orbit without crews for experimental purposes in September 2014. For such human-rated space capsules, the study of acceleration impacts against the human body during splashdown is essential to ensure the safety of crews. Moreover, it is also known that wearing a full pressure rescue suit significantly increases safety of a crew, compared to wearing a partial pressure suit. This is mainly because it enables the use of a personal life support system independently in addition to that which installed in the space vehicle. However, it is unclear how the inflation of the full pressure suit due to pressurization affects the crew safety during splashdown, especially in the case of the new generation manned space vehicles. Therefore, the purpose of this work is to investigate the effect of the suit inflation on crew safety against acceleration impact during splashdown. For this objective, the displacements of the safety harness in relation with the suit, a human surrogate, and the crew seats during pressurizing the suit in order to determine if the safety and survivability of a crew can be improved by wearing a full pressure suit. For these tests, the DL/H-1 full pressure IVA suit, developed by Pablo de Leon and Gary L. Harris, will be used. These tests use image analysis techniques to determine the displacements. It is expected, as a result of these tests, that wearing a full pressure suit will help to mitigate the impacts and will increase the safety and survivability of a crew during landing since it works as a buffer to mitigate impact forces during splashdown. This work also proposes a future plan for sled test experiments using a sled facility such as the one in use by the Civil Aerospace Medical Institute (CAMI) for experimental validation

  4. Cystic echinococcosis in the Arctic and Sub-Arctic.

    PubMed

    Rausch, R L

    2003-01-01

    The northern biotype of Echinococcus granulosus occurs throughout the holarctic zones of tundra and taiga, from eastern Fennoscandia to the Bering Strait in Eurasia and in North America from arctic Alaska approximately to the northern border of the United States. The cycle of the cestode is complex in taiga at lower latitudes, because of the greater diversity of potential hosts. In the Arctic and Subarctic, however, four patterns of predator/prey relationships may be discerned. Two natural cycles involve the wolf and wild reindeer and the wolf and elk (moose), respectively. Where deer of the two species coexist, both are prey of the wolf; the interactions of the wolf and elk are here described on the basis of long-term observations made on Isle Royale (in Lake Superior near the southern limit of taiga), where only the wolf and elk serve as hosts for E. granulosus. A synanthropic cycle involving herding-dogs and domesticated reindeer caused hyperendemicity of cystic echinococcosis in arctic Eurasia, mainly in northeastern Siberia. The 4th pattern, a semi-synanthropic cycle, formerly existed in Alaska, wherein sled-dogs of the indigenous hunters became infected by consuming the lungs of wild reindeer. The sequence of changes in life-style inherent in the process of acculturation affected the occurrence of cystic echinococcosis among nomadic Iñupiat in arctic Alaska. When those people became sedentary, the environs of their early villages soon became severely contaminated by faeces of dogs, and cases of cystic echinococcosis occurred. Compared to cystic echinococcosis caused by E. granulosus adapted to synanthropic hosts (dog and domestic ungulates), the infection produced by the northern biotype is relatively benign. Nearly all diagnosed cases of cystic echinococcosis (> 300) in Alaska have occurred in indigenous people; only one fatality has been recorded (in a non-indigenous person). After sled-dogs were replaced by machines, cases have become rare in Alaska. A

  5. Broadband Lidar Technique for Precision CO2 Measurement

    NASA Technical Reports Server (NTRS)

    Heaps, William S.

    2008-01-01

    Presented are preliminary experimental results, sensitivity measurements and discuss our new CO2 lidar system under development. The system is employing an erbium-doped fiber amplifier (EDFA), superluminescent light emitting diode (SLED) as a source and our previously developed Fabry-Perot interferometer subsystem as a detector part. Global measurement of carbon dioxide column with the aim of discovering and quantifying unknown sources and sinks has been a high priority for the last decade. The goal of Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission is to significantly enhance the understanding of the role of CO2 in the global carbon cycle. The National Academy of Sciences recommended in its decadal survey that NASA put in orbit a CO2 lidar to satisfy this long standing need. Existing passive sensors suffer from two shortcomings. Their measurement precision can be compromised by the path length uncertainties arising from scattering within the atmosphere. Also passive sensors using sunlight cannot observe the column at night. Both of these difficulties can be ameliorated by lidar techniques. Lidar systems present their own set of problems however. Temperature changes in the atmosphere alter the cross section for individual CO2 absorption features while the different atmospheric pressures encountered passing through the atmosphere broaden the absorption lines. Currently proposed lidars require multiple lasers operating at multiple wavelengths simultaneously in order to untangle these effects. The current goal is to develop an ultra precise, inexpensive new lidar system for precise column measurements of CO2 changes in the lower atmosphere that uses a Fabry-Perot interferometer based system as the detector portion of the instrument and replaces the narrow band laser commonly used in lidars with the newly available high power SLED as the source. This approach reduces the number of individual lasers used in the system from three or more

  6. Energy absorption capability of foam-based composite materials and their applications as seat cushions in aircraft crashworthiness

    NASA Astrophysics Data System (ADS)

    Kh. Beheshti, Hamid

    This study is focusing on the application of foam materials in aviation. These materials are being used for acoustic purposes, as padding in the finished interior panels of the aircraft, and as seat cushions. Foams are mostly used in seating applications. Since seat cushion is directly interacting with the body of occupant, it has to be ergonomically comfortable beside of absorbing the energy during the impact. All the seats and seat cushions have to pass regulations defined by Federal Aviation Administration (FAA). In fact, all airplane companies are required to certify the subcomponents of aircrafts before installing them on the main structure, fuselage. Current Federal Aviation Administration Regulations require a dynamic sled test of the entire seat system for certifying the seat cushions. This dynamic testing is required also for replacing the deteriorated cushions with new cushions. This involves a costly and time-consuming certification process. AGATE group has suggested a procedure based on quasi-static testing in order to certify new seat cushions without conducting full-scale dynamic sled testing. AGATE subcomponent methodology involves static tests of the energy-absorbing foam cushions and design validation by conducting a full-scale dynamic seat test. Microscopic and macroscopic studies are necessary to provide a complete understanding about performance of foams during the crash. Much investigation has been done by different sources to obtain the reliable modeling in terms of demonstration of mechanical behavior of foams. However, rate sensitivity of foams needs more attention. A mathematical hybrid dynamic model for the cushion underneath of the human body will be taken into consideration in this research. Analytical and finite element codes such as MADYMO and LS-DYNA codes have the potential to greatly speed up the crashworthy design process, to help certify seats and aircraft to dynamic crash loads, to predict seat and occupant response to impact

  7. Methods to mitigate injury to toddlers in near-side impact crashes.

    PubMed

    Kapoor, Tanya; Altenhof, William; Howard, Andrew; Rasico, Jim; Zhu, Fuchun

    2008-11-01

    This research focuses on the injury potential of children seated in forward-facing child safety seats during side impact crashes in a near-side seated position. Side impact dynamic sled tests were conducted by NHTSA at Transportation Research Center Inc. (TRC) using a Hybrid III 3-year-old child dummy seated in a convertible forward/rearward child safety seat. The seat was equipped with a LATCH and a top tether and the dummy was positioned in forward-facing/near-side configuration. The test was completed using an acceleration pulse with a closing speed of 24.1 km/h, in the presence of a rigid wall and absence of a vehicle body. A fully deformable finite element model of a child restraint seat, for side impact crash investigations, has been developed which has also been previously validated for frontal and far side impacts. A numerical model utilizing a Hybrid III 3-year-old dummy, employing a similar set-up as the experimental sled test was generated and simulated using LS DYNA. The numerical model was validated by comparing the head and the chest accelerations, resultant upper and lower neck forces and moments from the experimental and numerical tests. The simulation results were observed to be in good agreement to the experimental observations. A numerical model of the near-side laboratory tests, utilizing a Q3s child dummy, was also created for parametric studies regarding different ISOFIX configurations. Further, numerical simulations were completed for both the dummy models with rectangular and cross-shaped sections of rigid ISOFIX systems. In addition, studies were conducted to confine lateral movement of the dummy's head by adding energy absorbing foam on the side wings in the vicinity of the contact region of the CRS. It was observed that the use of rigid ISOFIX system reduced the lateral displacement of the CRS and different injury parameters. Addition of energy absorbing foam blocks was effective in further reducing the lateral displacement of the dummy

  8. Experimental injury study of children seated behind collapsing front seats in rear impacts.

    PubMed

    Saczalski, Kenneth J; Sances, Anthony; Kumaresan, Srirangam; Burton, Joseph L; Lewis, Paul R

    2003-01-01

    In the mid 1990's the U.S. Department of Transportation made recommendations to place children and infants into the rear seating areas of motor vehicles to avoid front seat airbag induced injuries and fatalities. In most rear-impacts, however, the adult occupied front seats will collapse into the rear occupant area and pose another potentially serious injury hazard to the rear-seated children. Since rear-impacts involve a wide range of speeds, impact severity, and various sizes of adults in collapsing front seats, a multi-variable experimental method was employed in conjunction with a multi-level "factorial analysis" technique to study injury potential of rear-seated children. Various sizes of Hybrid III adult surrogates, seated in a "typical" average strength collapsing type of front seat, and a three-year-old Hybrid III child surrogate, seated on a built-in booster seat located directly behind the front adult occupant, were tested at various impact severity levels in a popular "minivan" sled-buck test set up. A total of five test configurations were utilized in this study. Three levels of velocity changes ranging from 22.5 to 42.5 kph were used. The average of peak accelerations on the sled-buck tests ranged from approximately 8.2 G's up to about 11.1 G's, with absolute peak values of just over 14 G's at the higher velocity change. The parameters of the test configuration enabled the experimental data to be combined into a polynomial "injury" function of the two primary independent variables (i.e. front seat adult occupant weight and velocity change) so that the "likelihood" of rear child "injury potential" could be determined over a wide range of the key parameters. The experimentally derived head injury data was used to obtain a preliminary HIC (Head Injury Criteria) polynomial fit at the 900 level for the rear-seated child. Several actual accident cases were compared with the preliminary polynomial fit. This study provides a test efficient, multi

  9. Antenna Measurements: Test & Analysis of the Radiated Emissions/Immunity of the NASA/Orion Spacecraft Dart Parachute Simulator & Prototype Capsule - The Crew Exploration Vehicle

    NASA Technical Reports Server (NTRS)

    Norgard, John D.

    2012-01-01

    For future NASA Manned Space Exploration of the Moon and Mars, a blunt body capsule, called the Orion Crew Exploration Vehicle (CEV), composed of a Crew Module (CM) and a Service Module (SM), with a parachute decent assembly is planned for reentry back to Earth. A Capsule Parachute Assembly System (CPAS) is being developed for preliminary prototype parachute drop tests at the Yuma Proving Ground (YPG) to simulate high-speed reentry to Earth from beyond Low-Earth-Orbit (LEO) and to provide measurements of position, velocity, acceleration, attitude, temperature, pressure, humidity, and parachute loads. The primary and secondary (backup) avionics systems on CPAS also provide mission critical firing events to deploy, reef, and release the parachutes in three stages (extraction, drogues, mains) using mortars and pressure cartridge assemblies. In addition, a Mid-Air Delivery System (MDS) is used to separate the capsule from the sled that is used to eject the capsule from the back of the drop plane. Also, high-speed and high-definition cameras in a Video Camera System (VCS) are used to film the drop plane extraction and parachute landing events. Intentional and unintentional radiation emitted from and received by antennas and electronic devices on/in the CEV capsule, the MDS sled, and the VCS system are being tested for radiated emissions/immunity (susceptibility) (RE/RS). To verify Electromagnetic Compatibility (EMC) of the Orion capsule, Electromagnetic Interference (EMI) measurements are being made inside a semi-anechoic chamber at NASA/JSC on the components of the CPAS system. Measurements are made at 1m from the components-under-test (CUT). In addition, EMI measurements of the integrated CEV system are being made inside a hanger at YPG. These measurements are made in a complete circle, at 30? angles or less, around the Orion Capsule, the spacecraft system under-test (SUT). Near-field B-Dot probe measurements on the surface of the Orion capsule are being extrapolated

  10. Comparison Tests of BioRID II and RID 2 with Regard to Repeatability, Reproducibility and Sensitivity for Assessment of Car Seat Protection Potential in Rear-End Impacts.

    PubMed

    Bortenschlager, K; Kramberger, D; Barnsteiner, K; Hartlieb, M; Ferdinand, L; Leyer, H; Muser, M; Schmitt, K-U

    2003-10-01

    The objective of our study was to investigate the properties of the BioRID II and RID2 dummies regarding repeatability and reproducibility as well as their suitability to identify the protection potential of different car seats. For repeatability and reproducibility tests, three BioRID II and three RID 2 dummies at current build levels were seated on a rigid bench seat equipped with a head restraint, and mounted on a HyGe-type sled. The test velocity was prescribed by the proposed ISO-Pulse. For testing the interaction of the dummies with varying car seat geometries and mechanical properties and their ability to assess the protection potential of the seats, three seat types with passive and one seat with an active head restraint system from different car manufacturers were used. The seats were chosen due to their injury protection potential, indicated by accident field data and results of seat evaluation tests. One BioRID II equipped with a T1-load cell and one RID2 were positioned side-by-side on identical seats for each test. The tests were performed at velocities prescribed by the ISO-Pulse (deltav 16km/h / 8 g max.)and a more severe pulse (deltav 24km/h / 13 g max.). The dummy responses were interpreted by applying all currently proposed whiplash injury criteria (e.g. NIC, N(km), NDC, LNL). A comparison of these criteria shows their sensitivity for identification of the respective seat protection potential. This study examines the repeatability, reproducibility, kinematics and sensitivity of these two dummies in sled tests as well as their suitability with regard to the different injury criteria. The RID2 exhibited better repeatability and reproducibility than the BioRID II, because of its simpler mechanical design. The dummies did not give a consistent ranking of the low-speed, rear-end impact protection potentials of the four seat evaluated. More experience is needed to decide which dummy, injury criteria and limits should be used to assess the whiplash

  11. The Next Linear Collider Test Accelerator's RF Pulse Compression And Transmission

    SciTech Connect

    Tantawi, S.G.; Adelphson, C.; Holmes, S.; Lavine, Theodore L.; Loewen, R.J.; Nantista, C.; Pearson, C.; Pope, R.; Rifkin, J.; Ruth, R.D.; Vlieks, A.E.; /SLAC

    2011-09-14

    The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II* pulse compressor has been developed and successfully tested at high power. The system produced a 200 MW, 250 ns wide pulse with a near-perfect flat-top. In this paper we describe the design and test results of the high power pulse compression system using SLED-II. The NLC rf systems use low loss highly over-moded circular waveguides operating in the TE01 mode. The efficiency of the systems is sensitive to the mode purity of the mode excited inside these guides. We used the so called flower petal mode transducer [2] to excite the TE01 mode. This type of mode transducer is efficient, compact and capable of handling high levels of power. To make more efficient systems, we modified this device by adding several mode selective chokes to act as mode purifiers. To manipulate the rf signals we used these modified mode converters to convert back and forth between over-moded circular waveguides and single-moded WR90 rectangular waveguides. Then, we used the relatively simple rectangular waveguide components to do the actual manipulation of rf signals. For example, two mode transducers and a mitered rectangular waveguide bend comprise a 90 degree bend. Also, a magic tee and four mode transducers would comprise a four-port-hybrid, etc. We will discuss the efficiency of an rf transport system based on the above methodology. We also used this methodology in building the SLEDII pulse compression system. At SLAC we built 4 of these pulse systems. In this paper we describe the SLEDII system and compare the performance of these 4 systems at SLAC. We

  12. Evaluation of Human and Anthropomorphic Test Device Finite Element Models under Spaceflight Loading Conditions

    NASA Technical Reports Server (NTRS)

    Putnam, Jacob P.; Untaroiu, Costin; Somers. Jeffrey

    2014-01-01

    In an effort to develop occupant protection standards for future multipurpose crew vehicles, the National Aeronautics and Space Administration (NASA) has looked to evaluate the test device for human occupant restraint with the modification kit (THOR-K) anthropomorphic test device (ATD) in relevant impact test scenarios. With the allowance and support of the National Highway Traffic Safety Administration, NASA has performed a series of sled impact tests on the latest developed THOR-K ATD. These tests were performed to match test conditions from human volunteer data previously collected by the U.S. Air Force. The objective of this study was to evaluate the THOR-K finite element (FE) model and the Total HUman Model for Safety (THUMS) FE model with respect to the tests performed. These models were evaluated in spinal and frontal impacts against kinematic and kinetic data recorded in ATD and human testing. Methods: The FE simulations were developed based on recorded pretest ATD/human position and sled acceleration pulses measured during testing. Predicted responses by both human and ATD models were compared to test data recorded under the same impact conditions. The kinematic responses of the models were quantitatively evaluated using the ISO-metric curve rating system. In addition, ATD injury criteria and human stress/strain data were calculated to evaluate the risk of injury predicted by the ATD and human model, respectively. Results: Preliminary results show well-correlated response between both FE models and their physical counterparts. In addition, predicted ATD injury criteria and human model stress/strain values are shown to positively relate. Kinematic comparison between human and ATD models indicates promising biofidelic response, although a slightly stiffer response is observed within the ATD. Conclusion: As a compliment to ATD testing, numerical simulation provides efficient means to assess vehicle safety throughout the design process and further improve the

  13. A turbojet-boosted two-stage-to-orbit space transportation system design study

    NASA Technical Reports Server (NTRS)

    Hepler, A. K.; Zeck, H.; Walker, W.; Scharf, W.

    1979-01-01

    The concept to use twin turbo-powered boosters for acceleration to supersonic staging speed followed by an all rocket powered orbiter stage was proposed. A follow-on design study was then made of the concept with the performance objective of placing a 29,483 Kg payload into a .2.6 X 195.3 km orbit. The study was performed in terms of analysis and trade studies, conceptual design, utility and economic analysis, and technology assessment. Design features of the final configuration included: strakes and area rule for improved take off and low transonic drag, variable area inlets, exits and turbine, and low profile fixed landing gear for turbojet booster stage. The payload required an estimated GLOW of 1,270,000 kg for injection in orbit. Each twin booster required afterburning turbojet engines each with a static sea level thrust rating of 444,800 N. Life cycle costs for this concept were comparable to a SSTO/SLED concept except for increased development cost due to the turbojet engine propulsion system.

  14. Double domain wavelength multiplexed Fizeau interferometer with high resolution dynamic sensing and absolute length detection

    NASA Astrophysics Data System (ADS)

    Antonacci, Julián; Arenas, Gustavo F.; Duchowicz, Ricardo

    2017-04-01

    In this work, we present a simple photonic instrument that has the ability of measuring positions, distances and vibrations with very high resolution by means of two Fizeau interferometers (FI), both using the same optical fiber end as a probe tip itself. On the one hand we have a time domain FI powered with a 1310 nm laser and monitored by an InGaAs detector providing displacement information with resolution around a tenth of nm but regardless of the absolute position of object and of the displacement sense. On the other, a spectral domain FI version based on a super luminescent source (SLED) centred at 800 nm with bandwidth of nearly 40 nm is analysed in real time by means of a digital spectrometer. Each spectrum is acquired in a very small time interval and provides information of both length of the cavity as well as its correct sense of evolution. Resolution of this system is lower than its complementary temporal case, but distance and sense measurements are absolute and can be determined successfully by adequate processing of spectral signal.Both interferometers are optically coupled to a single fiber optic probe and are wavelength modulated.Therefore, combination of both sensors results in a new one which allows the correct knowledge of an object or surfaces under test, i.e. a high resolution of displacement data plus its absolute position and true sense of movement.

  15. Ferroelectric switch for a high-power Ka-band active pulse compressor

    SciTech Connect

    Hirshfield, Jay L.

    2013-12-18

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  16. A new NASA LaRC Multi-Purpose Prepregging Unit

    NASA Technical Reports Server (NTRS)

    Wilkinson, S. P.; Marchello, J. M.; Dixon, D.; Johnston, N. J.

    1993-01-01

    A multi-purpose prepregging machine has been designed and built for NASA Langley Research Center. The machine has numerous advantages over existing units due to its various modular components. Each of these can be used individually or simultaneously depending on the required prepregging method. A reverse roll coater provides the ability to prepare thin films from typical hot-melt thermoset formulations. Also, if necessary, the design allows direct fiber impregnation within the reverse roll coater gap. Included in the impregnation module is a solution dip tank allowing the fabrication of thermoplastic prepregs from solution. The proceeding modules within the unit consist of four nip stations, two hot-plates, a hot-sled option and a high temperature oven. This paper describes the advantages of such a modular construction and discusses the various processing combinations available to the prepregger. A variety of high performance prepreg material systems were produced on IM7 (Hercules) carbon fiber. These included LaRC RP46, a PMR-type resin processed from methanol and two polyamide acids, LaRC IA and LaRC ITPI, prpregged from N-methyl pyrrolidinone (NMP). Parameters involved in the production of these prepreg materials are presented as are the mechanical properties of the resulting good quality laminates. A brief introduction into the existing prepregging science is presented. Topics relating to solution prepregging are identified with a focus on the current research effort and its future development.

  17. Biomechanical assessment of a rear-seat inflatable seatbelt in frontal impacts.

    PubMed

    Sundararajan, Srinivasan; Rouhana, Stephen W; Board, Derek; DeSmet, Ed; Prasad, Priya; Rupp, Jonathan D; Miller, Carl S; Schneider, Lawrence W

    2011-11-01

    This study evaluated the biomechanical performance of a rear-seat inflatable seatbelt system and compared it to that of a 3-point seatbelt system, which has a long history of good real-world performance. Frontal-impact sled tests were conducted with Hybrid III anthropomorphic test devices (ATDs) and with post mortem human subjects (PMHS) using both restraint systems and a generic rear-seat configuration. Results from these tests demonstrated: a) reduction in forward head excursion with the inflatable seatbelt system when compared to that of a 3-point seatbelt and; b) a reduction in ATD and PMHS peak chest deflections and the number of PMHS rib fractures with the inflatable seatbelt system and c) a reduction in PMHS cervical-spine injuries, due to the interaction of the chin with the inflated shoulder belt. These results suggest that an inflatable seatbelt system will offer additional benefits to some occupants in the rear seats. Further research is needed to assess the field effectiveness, customer comfort and acceptance and change in the belt usage rate with the inflatable seatbelt system.

  18. Biomechanical impact response of the human chin and manubrium.

    PubMed

    Stammen, Jason A; Bolte, John H; Shaw, Joshua

    2012-03-01

    Chin-to-chest impact commonly occurs in frontal crash simulations with restrained anthropomorphic test devices (ATDs) in non-airbag situations. This study investigated the biofidelity of this contact by evaluating the impact response of both the chin and manubrium of adult post-mortem human subjects (PMHSs). The adult PMHS data were scaled to a 10-year-old (YO) human size and then compared with the Hybrid III 10YO child (HIII-10C) ATD response with the same test configurations. For both the chin and manubrium, the responses of the scaled PMHS had different characteristics than the HIII-10C ATD responses. Elevated energy impact tests to the PMHS mandible provided a mean injury tolerance value for chin impact force. Chin contact forces in the HIII-10C ATD were calculated in previously conducted HYGE sled crash simulation tests, and these contact forces were strongly correlated with the Head Injury Criterion (HIC(36 ms)). The mean injurious force from the PMHS tests corresponded to a HIC(36 ms) value that would predict an elevated injury risk if it is assumed that fractures of the chin and skull are similarly correlated with HIC(36 ms). Given the rarity of same occupant-induced chin injury in booster-seated occupants in real crash data and the disparity in chin and manubrium stiffnesses between scaled PMHS and HIII-10C ATD, the data from this study can be made use of to improve biofidelity of chin-to-manubrium contact in ATDs.

  19. Bicycle helmet use and non-use - recently published research.

    PubMed

    Uibel, Stefanie; Müller, Daniel; Klingelhoefer, Doris; Groneberg, David A

    2012-05-25

    Bicycle traumata are very common and especially neurologic complications lead to disability and death in all stages of the life. This review assembles the most recent findings concerning research in the field of bicycle traumata combined with the factor of bicycle helmet use. The area of bicycle trauma research is by nature multidisciplinary and relevant not only for physicians but also for experts with educational, engineering, judicial, rehabilitative or public health functions. Due to this plurality of global publications and special subjects, short time reviews help to detect recent research directions and provide also information from neighbour disciplines for researchers. It can be stated that to date, that although a huge amount of research has been conducted in this area more studies are needed to evaluate and improve special conditions and needs in different regions, ages, nationalities and to create successful prevention programs of severe head and face injuries while cycling.Focus was explicit the bicycle helmet use, wherefore sledding, ski and snowboard studies were excluded and only one study concerning electric bicycles remained due to similar motion structures within this review. The considered studies were all published between January 2010 and August 2011 and were identified via the online databases Medline PubMed and ISI Web of Science.

  20. Head and neck response of a finite element anthropomorphic test device and human body model during a simulated rotary-wing aircraft impact.

    PubMed

    White, Nicholas A; Danelson, Kerry A; Gayzik, F Scott; Stitzel, Joel D

    2014-11-01

    A finite element (FE) simulation environment has been developed to investigate aviator head and neck response during a simulated rotary-wing aircraft impact using both an FE anthropomorphic test device (ATD) and an FE human body model. The head and neck response of the ATD simulation was successfully validated against an experimental sled test. The majority of the head and neck transducer time histories received a CORrelation and analysis (CORA) rating of 0.7 or higher, indicating good overall correlation. The human body model simulation produced a more biofidelic head and neck response than the ATD experimental test and simulation, including change in neck curvature. While only the upper and lower neck loading can be measured in the ATD, the shear force, axial force, and bending moment were reported for each level of the cervical spine in the human body model using a novel technique involving cross sections. This loading distribution provides further insight into the biomechanical response of the neck during a rotary-wing aircraft impact.

  1. Test Report for Perforated Metal Air Transportable Package (PMATO) Prototype.

    SciTech Connect

    Bobbe, Jeffery G.; Pierce, Jim Dwight

    2003-06-01

    A prototype design for a plutonium air transport package capable of carrying 7.6 kg of plutonium oxide and surviving a ''worst-case'' plane crash has been developed by Sandia National Laboratories (SNL) for the Japan Nuclear Cycle Development Institute (JNC). A series of impact tests were conducted on half-scale models of this design for side, end, and comer orientations at speeds close to 282 m/s onto a target designed to simulate weathered sandstone. These tests were designed to evaluate the performance of the overpack concept and impact-limiting materials in critical impact orientations. The impact tests of the Perforated Metal Air Transportable Package (PMATP) prototypes were performed at SNL's 10,000-ft rocket sled track. This report describes test facilities calibration and environmental testing methods of the PMATP under specific test conditions. The tests were conducted according to the test plan and procedures that were written by the authors and approved by SNL management and quality assurance personnel. The result of these tests was that the half-scale PMATP survived the ''worst-case'' airplane crash conditions, and indicated that a full-scale PMATP, utilizing this overpack concept and these impact-limiting materials, would also survive these crash conditions.

  2. Kinematics of the unrestrained vehicle occupants in side-impact crashes.

    PubMed

    Riley, P O; Arregui-Dalmases, C; Purtserov, S; Parent, D; Lessley, D J; Shaw, G; Crandall, J; Takayama, Shinichi; Ono, Koshiro; Kamiji, Koichi; Yasuki, Tsuyoshi

    2012-01-01

    A test series involving direct right-side impact of a moving wall on unsupported, unrestrained cadavers with no arms was undertaken to better understand human kinematics and injury mechanisms during side impact at realistic speeds. The tests conducted provided a unique opportunity for a detailed analysis of the kinematics resulting from side impact. Specifically, this study evaluated the 3-dimensional (3D) kinematics of 3 unrestrained male cadavers subjected to lateral impact by a multi-element load wall carried by a pneumatically propelled rail-mounted sled reproducing a conceptual side crash impact. Three translations and 3 rotations characterize the movement of a solid body in the space, the 6 degrees of freedom (6DoF) kinematics of 15 bone segments were obtained from the 3D marker motions and computed tomography (CT)-defined relationships between the maker array mounts and the bones. The moving wall initially made contact with the lateral aspect of the pelvis, which initiated lateral motion of the spinal segments beginning with the pelvis and moving sequentially up through the lumbar spine to the thorax. Analyzing the 6DoF motions kinematics of the ribs and sternum followed right shoulder contact with the wall. Overall thoracic motion was assessed by combining the thoracic bone segments as a single rigid body. The kinematic data presented in this research provides quantified subject responses and boundary condition interactions that are currently unavailable for lateral impact.

  3. Structure, function and dynamics in adenovirus maturation.

    PubMed

    Mangel, Walter F; San Martín, Carmen

    2014-11-21

    Here we review the current knowledge on maturation of adenovirus, a non-enveloped icosahedral eukaryotic virus. The adenovirus dsDNA genome fills the capsid in complex with a large amount of histone-like viral proteins, forming the core. Maturation involves proteolytic cleavage of several capsid and core precursor proteins by the viral protease (AVP). AVP uses a peptide cleaved from one of its targets as a "molecular sled" to slide on the viral genome and reach its substrates, in a remarkable example of one-dimensional chemistry. Immature adenovirus containing the precursor proteins lacks infectivity because of its inability to uncoat. The immature core is more compact and stable than the mature one, due to the condensing action of unprocessed core polypeptides; shell precursors underpin the vertex region and the connections between capsid and core. Maturation makes the virion metastable, priming it for stepwise uncoating by facilitating vertex release and loosening the condensed genome and its attachment to the icosahedral shell. The packaging scaffold protein L1 52/55k is also a substrate for AVP. Proteolytic processing of L1 52/55k disrupts its interactions with other virion components, providing a mechanism for its removal during maturation. Finally, possible roles for maturation of the terminal protein are discussed.

  4. The 1925 Diphtheria Antitoxin Run to Nome - Alaska: A Public Health Illustration of Human-Animal Collaboration.

    PubMed

    Aboul-Enein, Basil H; Puddy, William C; Bowser, Jacquelyn E

    2016-12-29

    Diphtheria is an acute toxin-mediated superficial infection of the respiratory tract or skin caused by the aerobic gram-positive bacillus Corynebacterium diphtheriae. The epidemiology of infection and clinical manifestations of the disease vary in different parts of the world. Historical accounts of diphtheria epidemics have been described in many parts of the world since antiquity. Developed in the late 19th century, the diphtheria antitoxin (DAT) played a pivotal role in the history of public health and vaccinology prior to the advent of the diphtheria-tetanus toxoids and acellular pertussis (DTaP) vaccine. One of the most significant demonstrations of the importance of DAT was its use in the 1925 diphtheria epidemic of Nome, Alaska. Coordinated emergency delivery of this life-saving antitoxin by dog-sled relay in the harshest of conditions has left a profound legacy in the annals of vaccinology and public health. Lead dogs Balto and Togo, and the dog-led antitoxin run of 1925 represent a dynamic illustration of the contribution made by non-human species towards mass immunization in the history of vaccinology. This unique example of cooperative interspecies fellowship and collaboration highlights the importance of the human-animal bond in the one-health initiative.

  5. Passive flooding of paranasal sinuses and middle ears as a method of equalisation in extreme breath-hold diving.

    PubMed

    Germonpré, Peter; Balestra, Costantino; Musimu, Patrick

    2011-06-01

    Breath-hold diving is both a recreational activity, performed by thousands of enthusiasts in Europe, and a high-performance competitive sport. Several 'disciplines' exist, of which the 'no-limits' category is the most spectacular: using a specially designed heavy 'sled,' divers descend to extreme depths on a cable, and then reascend using an inflatable balloon, on a single breath. The current world record for un-assisted descent stands at more than 200 m of depth. Equalising air pressure in the paranasal sinuses and middle-ear cavities is a necessity during descent to avoid barotraumas. However, this requires active insufflations of precious air, which is thus unavailable in the pulmonary system. The authors describe a diver who, by training, is capable of allowing passive flooding of the sinuses and middle ear with (sea) water during descent, by suppressing protective (parasympathetic) reflexes during this process. Using this technique, he performed a series of extreme-depth breath-hold dives in June 2005, descending to 209 m of sea water on one breath of air.

  6. Environmental assessment of general-purpose heat source safety verification testing

    SciTech Connect

    1995-02-01

    This Environmental Assessment (EA) was prepared to identify and evaluate potential environmental, safety, and health impacts associated with the Proposed Action to test General-Purpose Heat Source (GPHS) Radioisotope Thermoelectric Generator (RTG) assemblies at the Sandia National Laboratories (SNL) 10,000-Foot Sled Track Facility, Albuquerque, New Mexico. RTGs are used to provide a reliable source of electrical power on board some spacecraft when solar power is inadequate during long duration space missions. These units are designed to convert heat from the natural decay of radioisotope fuel into electrical power. Impact test data are required to support DOE`s mission to provide radioisotope power systems to NASA and other user agencies. The proposed tests will expand the available safety database regarding RTG performance under postulated accident conditions. Direct observations and measurements of GPHS/RTG performance upon impact with hard, unyielding surfaces are required to verify model predictions and to ensure the continual evolution of the RTG designs that perform safely under varied accident environments. The Proposed Action is to conduct impact testing of RTG sections containing GPHS modules with simulated fuel. End-On and Side-On impact test series are planned.

  7. The impact of relative intensity noise on the signal in multiple reference optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Neuhaus, Kai; Subhash, Hrebesh; Alexandrov, Sergey; Dsouza, Roshan; Hogan, Josh; Wilson, Carol; Leahy, Martin; Slepneva, Svetlana; Huyet, Guillaume

    2016-03-01

    Multiple reference optical coherence tomography (MR-OCT) applies a unique low-cost solution to enhance the scanning depth of standard time domain OCT by inserting an partial mirror into the reference arm of the interferometric system. This novel approach achieves multiple reflections for different layers and depths of an sample with minimal effort of engineering and provides an excellent platform for low-cost OCT systems based on well understood production methods for micro-mechanical systems such as CD/DVD pick-up systems. The direct integration of a superluminescent light-emitting diode (SLED) is a preferable solution to reduce the form- factor of an MR-OCT system. Such direct integration exposes the light source to environmental conditions that can increase fluctuations in heat dissipation and vibrations and affect the noise characteristics of the output spectrum. This work describes the impact of relative intensity noise (RIN) on the quality of the interference signal of MR-OCT related to a variety of environmental conditions, such as temperature.

  8. Sidescan sonar imagery of widespread fossil and active cold seeps along the central Chilean continental margin

    NASA Astrophysics Data System (ADS)

    Klaucke, Ingo; Weinrebe, Wilhelm; Linke, Peter; Kläschen, Dirk; Bialas, Jörg

    2012-12-01

    The central Chilean subduction zone between 35°S and 37°S was investigated in order to identify, document and possibly understand fluid flow and fluid venting within the forearc region. Several areas were mapped using multibeam bathymetry and backscatter, high-resolution sidescan sonar, chirp subbottom profiling and reflection seismic data. On a subsequent cruise ground-truthing observations were made using a video sled. In general, this dataset shows surprisingly little evidence of fluid venting along the mid-slope region, in contrast to other subduction zones such as Central America and New Zealand. There were abundant indications of active and predominantly fossil fluid venting along the upper slope between 36.5°S and 36.8°S at the seaward margin of an intraslope basin. Here, backscatter anomalies suggest widespread authigenic carbonate deposits, likely the result of methane-rich fluid expulsion. There is unpublished evidence that these fluids are of biogenic origin and generated within the slope sediments, similar to other accretionary margins but in contrast to the erosional margin off Central America, where fluids have geochemical signals indicating an origin from the subducting plate.

  9. Reliability-Based Weighting of Visual and Vestibular Cues in Displacement Estimation

    PubMed Central

    ter Horst, Arjan C.; Koppen, Mathieu; Selen, Luc P. J.; Medendorp, W. Pieter

    2015-01-01

    When navigating through the environment, our brain needs to infer how far we move and in which direction we are heading. In this estimation process, the brain may rely on multiple sensory modalities, including the visual and vestibular systems. Previous research has mainly focused on heading estimation, showing that sensory cues are combined by weighting them in proportion to their reliability, consistent with statistically optimal integration. But while heading estimation could improve with the ongoing motion, due to the constant flow of information, the estimate of how far we move requires the integration of sensory information across the whole displacement. In this study, we investigate whether the brain optimally combines visual and vestibular information during a displacement estimation task, even if their reliability varies from trial to trial. Participants were seated on a linear sled, immersed in a stereoscopic virtual reality environment. They were subjected to a passive linear motion involving visual and vestibular cues with different levels of visual coherence to change relative cue reliability and with cue discrepancies to test relative cue weighting. Participants performed a two-interval two-alternative forced-choice task, indicating which of two sequentially perceived displacements was larger. Our results show that humans adapt their weighting of visual and vestibular information from trial to trial in proportion to their reliability. These results provide evidence that humans optimally integrate visual and vestibular information in order to estimate their body displacement. PMID:26658990

  10. Electromyography responses of pediatric and young adult volunteers in low-speed frontal impacts.

    PubMed

    Mathews, Emily A; Balasubramanian, Sriram; Seacrist, Thomas; Maltese, Matthew R; Sterner, Robert; Arbogast, Kristy B

    2013-10-01

    No electromyography (EMG) responses data exist of children exposed to dynamic impacts similar to automotive crashes, thereby, limiting active musculature representation in computational occupant biomechanics models. This study measured the surface EMG responses of three neck, one torso and one lower extremity muscles during low-speed frontal impact sled tests (average maximum acceleration: 3.8g; rise time: 58.2ms) performed on seated, restrained pediatric (n=11, 8-14years) and young adult (n=9, 18-30years) male subjects. The timing and magnitude of the EMG responses were compared between the two age groups. Two normalization techniques were separately implemented and evaluated: maximum voluntary EMG (MVE) and neck cross-sectional area (CSA). The MVE-normalized EMG data indicated a positive correlation with age in the rectus femoris for EMG latency; there was no correlation with age for peak EMG amplitudes for the evaluated muscles. The cervical paraspinous exhibited shorter latencies compared with the other muscles (2-143ms). Overall, the erector spinae and rectus femoris peak amplitudes were relatively small. Neck CSA-normalized peak EMG amplitudes negatively correlated with age for the cervical paraspinous and sternocleidomastoid. These data can be useful to incorporate active musculature in computational models, though it may not need to be age-specific in low-speed loading environments.

  11. Spinal canal narrowing during simulated frontal impact.

    PubMed

    Ivancic, Paul C; Panjabi, Manohar M; Tominaga, Yasuhiro; Pearson, Adam M; Elena Gimenez, S; Maak, Travis G

    2006-06-01

    Between 23 and 70% of occupants involved in frontal impacts sustain cervical spine injuries, many with neurological involvement. It has been hypothesized that cervical spinal cord compression and injury may explain the variable neurological profile described by frontal impact victims. The goals of the present study, using a biofidelic whole cervical spine model with muscle force replication, were to quantify canal pinch diameter (CPD) narrowing during frontal impact and to evaluate the potential for cord compression. The biofidelic model and a sled apparatus were used to simulate frontal impacts at 4, 6, 8, and 10 g horizontal accelerations of the T1 vertebra. The CPD was measured in the intact specimen in the neutral posture (neutral posture CPD), under static sagittal pure moments of 1.5 Nm (pre-impact CPD), during dynamic frontal impact (dynamic impact CPD), and again under static pure moments following each impact (post-impact CPD). Frontal impact caused significant (P<0.05) dynamic CPD narrowing at C0-dens, C2-C3, and C6-C7. The narrowest dynamic CPD was observed at C0-dens during the 10 g impact and was 25.9% narrower than the corresponding neutral posture CPD. Interpretation of the present results indicate that the neurological symptomatology reported by frontal impact victims is most likely not due to cervical spinal cord compression. Cord compression due to residual spinal instability is also not likely.

  12. Preconceptions of Japanese Students Surveyed Using the Force and Motion Conceptual Evaluation

    NASA Astrophysics Data System (ADS)

    Ishimoto, Michi

    2010-07-01

    We assess the preconceptions of Japanese students about force and motion. The Force and Motion Conceptual Evaluation is a research-based, multiple-choice assessment of students' conceptual understanding of Newton's laws of motion and energy conservation. It is administered to determine the effectiveness of introductory mechanics curricula. In this study, the test was given to engineering students at the beginning of the first lecture of an introductory mechanics course for several years. Some students had minimal high school physics education, whereas the others had completed high school physics programs. To probe the students' preconceptions, we studied their test answers for each of the following categories: velocity, acceleration, Newton's first and second laws, Newton's third law, and energy conservation. We find that preconceptions, such as F ∝ mv, are prevalent among the students, regardless of their level of high school physics education. In the case of a collision between two objects, two preconceptions—a mass-dependent model and an action-dependent model—are prevalent. Typically, students combine the two models, with action dependency outweighing mass dependency. In the case of a sled sliding down a hill without friction at two heights and inclinations, a quarter of students used the height-dependent model to answer questions regarding speed and kinetic energy.

  13. Illustrations of the importance of mass wasting in the evolution of continental margins

    SciTech Connect

    Pratson, L.; Ryan, W. ); Twichell, D. )

    1990-05-01

    Side-looking sonar imagery and swath bathymetry from a variety of contemporary continental slopes all display erosional scars and debris aprons, illustrating the importance of mass wasting in the evolution of continental margins. The continental slopes examined include slopes fed directly from the fronts of ice sheets, slopes adjacent to continental shelves that were the sites of glacial outwash, slopes supplied exclusively by fluvial drainage, slopes at carbonate platforms, and slopes on accretionary prisms. Examples are drawn from the Atlantic Ocean, the Gulf of Mexico, and the Mediterranean Sea in both passive and active continental margin settings. The sonar imagery and bathymetry used in this study indicate that continental slopes in different tectonic and climatic environments show similar forms of mass wasting. However, in some cases the dominant mode of erosion and/or the overall degree of mass wasting appears to be distinct to particular sedimentary environments. Timing of both recent and older exhumed erosional surfaces identified in the imagery and in seismic reflection profiles is obtained by ground truth observations using submersibles, towed camera sleds, drilling, and coring. These observations suggest that eustatic fluctuations common to all the margins examined do not explain the range in magnitude and areal density of the observed mass wasting. More localized factors such as lithology, diagenesis, pore fluid conditions, sediment supply rates, and seismic ground motion appear to have a major influence in the evolution of erosional scars and their corresponding unconformities.

  14. Using multiple markers to elucidate the ancient, historical and modern relationships among North American Arctic dog breeds.

    PubMed

    Brown, S K; Darwent, C M; Wictum, E J; Sacks, B N

    2015-12-01

    Throughout most of the Americas, post-colonial dogs largely erased the genetic signatures of pre-historical dogs. However, the North American Arctic harbors dogs that are potentially descended from pre-historical ancestors, as well as those affected by post-colonial translocations and admixtures. In particular, Inuit dogs from Canada and Greenland are thought to descend from dogs associated with Thule peoples, who relied on them for transportation ca. 1000 years ago. Whether Thule dogs reflected an earlier colonization by Paleoeskimo dogs ca. 4500 years ago is unknown. During the Alaskan Gold Rush, additional sled dogs, possibly of post-colonial derivation, the Alaskan Husky, Malamute and Siberian Husky, were used in the Arctic. The genealogical relationships among and origins of these breeds are unknown. Here we use autosomal, paternal and maternal DNA markers to (1) test the hypothesis that Inuit dogs have retained their indigenous ancestry, (2) characterize their relationship to one another and to other Arctic breeds, and (3) estimate the age of North American indigenous matrilines and patrilines. On the basis of the agreement of all three markers we determined that Inuit dogs have maintained their indigenous nature, and that they likely derive from Thule dogs. In addition, we provide support for previous research that the Inuit dogs from Canada and Greenland dog should not be distinguished as two breeds. The Alaskan Husky displayed evidence of European introgression, in contrast to the Malamute and Siberian Husky, which appear to have maintained most of their ancient Siberian ancestry.

  15. Reliability-Based Weighting of Visual and Vestibular Cues in Displacement Estimation.

    PubMed

    ter Horst, Arjan C; Koppen, Mathieu; Selen, Luc P J; Medendorp, W Pieter

    2015-01-01

    When navigating through the environment, our brain needs to infer how far we move and in which direction we are heading. In this estimation process, the brain may rely on multiple sensory modalities, including the visual and vestibular systems. Previous research has mainly focused on heading estimation, showing that sensory cues are combined by weighting them in proportion to their reliability, consistent with statistically optimal integration. But while heading estimation could improve with the ongoing motion, due to the constant flow of information, the estimate of how far we move requires the integration of sensory information across the whole displacement. In this study, we investigate whether the brain optimally combines visual and vestibular information during a displacement estimation task, even if their reliability varies from trial to trial. Participants were seated on a linear sled, immersed in a stereoscopic virtual reality environment. They were subjected to a passive linear motion involving visual and vestibular cues with different levels of visual coherence to change relative cue reliability and with cue discrepancies to test relative cue weighting. Participants performed a two-interval two-alternative forced-choice task, indicating which of two sequentially perceived displacements was larger. Our results show that humans adapt their weighting of visual and vestibular information from trial to trial in proportion to their reliability. These results provide evidence that humans optimally integrate visual and vestibular information in order to estimate their body displacement.

  16. Seasonal Alterations in Park Visitation, Amenity Use, and Physical Activity — Grand Forks, North Dakota, 2012–2013

    PubMed Central

    Johnson, LuAnn

    2014-01-01

    Introduction Park amenities promote visitation and physical activity during summer. Physical activity declines during winter. Identifying park amenities that promote visitation during winter would increase year-round activity. The purpose of this study was to determine how park visitation, amenity choice, and physical activity intensity change across seasons. Methods Physical activity intensity of children and adults was assessed at 16 parks in Grand Forks, North Dakota, during summer and fall of 2012, and winter and spring of 2013. Results Park visitation was highest in spring and lowest in winter. Amenity use varied by season. Parks with water splash pads were visited more during summer, and playgrounds and open spaces were visited more during spring. Ice rinks were visited most in winter. Physical activity intensity was lowest in summer and highest in winter for each age group. The activity intensity observed for all young age groups ranged from 2.7 to 2.9 metabolic equivalents in summer and greater than 3 metabolic equivalents in all other seasons. Adults’ mean activity intensity was greater than 3 metabolic equivalents in winter. Conclusion Information on park visitation, amenity use, and activity intensity across seasons is valuable; it can be used when designing or redesigning parks in order to promote year-round physical activity. Redesigning parks in cold climates to include ice rinks, sledding hills, cross-country skiing, and indoor areas for physical activity would increase winter visitation and allow the park to serve as a year-round resource for physical activity. PMID:25211503

  17. Influence of the postion of crew members on aerodynamics performance of two-man bobsleigh.

    PubMed

    Dabnichki, Peter; Avital, Eldad

    2006-01-01

    Bobsleigh aerodynamics has long been recognised as one of the crucial performance factors. Although the published research in the area is very limited, it is well known that the leading nations in the sport devote significant resources in research and development of sleds' aerodynamics. However, the rules and regulations pose strict design constraints on the shape modifications aiming at aerodynamics improvements. The reason for that is two-fold: (i) safety of the athletes and (ii) reduction of equipment impact on competition outcome. One particular area that has not been looked at and falls outside the current rules and regulations is the influence of the crew positioning and internal modifications on the aerodynamic performance. The current study presents results on numerical simulation of the flow in the cavity underpinned with some experimental measurements including flow visualisation of the air circulation around the bobsleigh. A simplified computational model was developed to assess the trends and its results validated by windtunnel tests. The results show that crew members influence the drag level significantly and suggest that purely internal modifications can be introduced to reduce the overall resistance drag.

  18. The ecosystem service value of living versus dead biogenic reef

    NASA Astrophysics Data System (ADS)

    Sheehan, E. V.; Bridger, D.; Attrill, M. J.

    2015-03-01

    Mixed maerl beds (corralline red algae) comprise dead thalli with varying amounts of live maerl fragments, but previously it was not known whether the presence of the live maerl increases the ecosystem service 'habitat provision' of the dead maerl for the associated epibenthos. A 'flying array' towed sled with high definition video was used to film transects of the epibenthos in dead maerl and mixed maerl beds in two locations to the north and south of the English Channel (Falmouth and Jersey). Mixed maerl beds supported greater number of taxa and abundance than dead beds in Falmouth, while in Jersey, mixed and dead beds supported similar number of taxa and dead beds had a greater abundance of epifauna. Scallops tended to be more abundant on mixed beds than dead beds. Tube worms were more abundant on mixed beds in Falmouth and dead beds in Jersey. An increasing percentage occurrence of live maerl thalli correlated with increasing number of taxa in Falmouth but not Jersey. It was concluded that while live thalli can increase the functional role of dead maerl beds for the epibenthos, this is dependent on location and response variable. As a result of this work, maerl habitat in SE Jersey has been protected from towed demersal fishing gear.

  19. Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

    USGS Publications Warehouse

    Walsh, Maureen G.; Lantry, Brian F.; Boscarino, Brent; Bowen, Kelly; Gerlofsma, Jocelyn; Schaner, Ted; Back, Richard; Questel, Jennifer; Smythe, A. Garry; Cap, Roberta; Goehle, Michael; Young, Bryan; Chalupnicki, Marc A.; Johnson, James H.; McKenna, James E.

    2010-01-01

    Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0. mm and an average caloric density of 611. cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.

  20. Active MMI devices: concept, proof, and recent progress

    NASA Astrophysics Data System (ADS)

    Hamamoto, Kiichi; Jiang, Haisong

    2015-09-01

    Multi-mode interference (MMI) couplers (waveguides) are widely studied and developed as key components of photonic integrated circuits, including power coupler/dividers, and others. Furthermore, another possibility utilizing MMI has been investigated on active devices so far. Owing to the wider area of the multi-mode waveguide section compared with that of the regular single-mode waveguide, MMI may result in higher performance (high power, low power consumption, and others) rather than conventional active devices while maintaining regular single-mode output. Thus, active multi-mode interferometer (active-MMI) devices, including laser diodes (LDs), super-luminescent light emitting diodes (SLEDs), and semiconductor optical amplifiers (SOAs) have been studied. Moreover, they have been also exploited to bi-stable LDs and single wavelength emitters, and others using the interference inside the MMI section. In this paper, we review and summarize the recent progress in active MMI devices. We provide proof of MMI phenomena in active waveguides and discuss the results.

  1. Full-scale turbine-missile-casing tests. Final report. [PWR; BWR

    SciTech Connect

    Yoshimura, H.R.; Schamaun, J.T.

    1983-01-01

    Results are presented of two full-scale tests simulating the impact of turbine disk fragments on simple ring and shell structures that represent the internal stator blade ring and the outer housing of an 1800-rpm steam turbine casing. The objective was to provide benchmark data on both the energy-absorbing mechanisms of the impact process and, if breakthrough occured, the exit conditions of the turbine missile. A rocket sled was used to accelerate a 1527-kg (3366-lb) segment of a turbine disk, which impacted a steel ring 12.7 cm (5 in.) thick and a steel shell 3.2 cm (1.25 in.) thick. The impact velocity of about 150 m/s (492 ft/s) gave a missile kinetic energy corresponding to the energy of a fragment from a postulated failure at the design overspeed (120% of operating speed). Depending on the orientation of the missile at impact, the steel test structure either slowed the missile to 60% of its initial translational velocity or brought it almost to rest (an energy reduction of 65 and 100%, respectively). The report includes structural and finite element analysis and data interpretation, estimates of energy during impact, missile displacement and velocity histories, and selected strain gage data.

  2. Rear impact responses of different sized adult Hybrid III dummies.

    PubMed

    DeRosia, John; Yoganandan, Narayan; Pintar, Frank A

    2004-03-01

    Rear impact sled tests were conducted using 5th, 50th, and 95th percentile Hybrid III dummies to evaluate proposed injury criteria. Different head restraint height (750, 800 mm) and backset (0, 50, 100 mm) positions were used to determine axial and shear forces, bending moments, and injury criteria (NIC, N(ij), and N(km)). The time sequence to attain each parameter was also determined. Three events were identified in the response. Event I was coincident with the maximum rearward motion of the torso, Event II occurred at the time of the peak upper neck flexion moment, and Event III occurred at the time of maximum rearward motion of the head. Parameters such as backset, head restraint height, seat-head restraint interaction, and anthropometry affected impact responses. Head rotations increased with increasing backset and increasing head restraint height. However, N(ij) and N(km) did not exhibit such clear trends. The 50th percentile dummy responded with consistent injury criteria values (e.g., the magnitude of the injury criteria increased with backset increase or head restraint height decrease). However, the 5th and 95th percentile dummies did not demonstrate such trends. These findings underscore the need to include subject anthropometry in addition to seat and head restraint characteristics for better assessment of rear impact responses.

  3. Feasibility study on conducting overflight measurements of shaped sonic boom signatures using the Firebee BQM-34E RPV

    NASA Astrophysics Data System (ADS)

    Maglieri, Domenic J.; Sothcott, Victor E.; Keefer, Thomas N., Jr.

    1993-02-01

    A study was performed to determine the feasibility of establishing if a 'shaped' sonic boom signature, experimentally shown in wind tunnel models out to about 10 body lengths, will persist out to representative flight conditions of 200 to 300 body lengths. The study focuses on the use of a relatively large supersonic remotely-piloted and recoverable vehicle. Other simulation methods that may accomplish the objective are also addressed and include the use of nonrecoverable target drones, missiles, full-scale drones, very large wind tunnels, ballistic facilities, whirling-arm techniques, rocket sled tracks, and airplane nose probes. In addition, this report will also present a background on the origin of the feasibility study including a brief review of the equivalent body concept, a listing of the basic sonic boom signature characteristics and requirements, identification of candidate vehicles in terms of desirable features/availability, and vehicle characteristics including geometries, area distributions, and resulting sonic boom signatures. A program is developed that includes wind tunnel sonic boom and force models and tests for both a basic and modified vehicles and full-scale flight tests.

  4. The design research of a spinel dome

    NASA Astrophysics Data System (ADS)

    Zhao, Hongwei; Hou, Tianjin; Zhu, Bin; Huang, Qiu; Gao, Zhifeng

    2011-08-01

    Based on the aerodynamic heating simulated results of a spinel middle-infrared (Mid IR) image guide missile dome flying at supersonic speed, a series of experiments are made and some methods of eliminating aero-heating effect are carried out successfully. First, a simulation experiment on the ground discarding an outside protective shell of a spinel dome is accomplished in order to inspect the withstanding impact ability of the dome. Second, an arc wind tunnel experiment is fulfilled to obtain thermal mechanics characteristic of the spinel dome, and a method to buildup obviously mechanics intensity is approved which is coating diamond protective layer on the external wall of the spinel dome. Third, two heated dome imaging experiments on the ground are made to study the aero-optical phenomenon. Finally, a rocket sled experiment of a guide missile head is made successfully. Experimental results show that when the guide missile head flies in a supersonic, by adjusting the frame integration time of detector etc. the aero-optic effect would decrease greatly.

  5. Retrospective of photography at NASA Ames Research Center from 1940 to 1996 (Extended Abstract)

    NASA Astrophysics Data System (ADS)

    Ponseggi, Bernard G.

    1997-05-01

    This paper deals with what is known as photo/optical instrumentation technology and/or technical photography. In 1940 this was called photography, in the late 40's the Civil Service Commission introduced a new classification called photography/technical to differentiate between still photographers and those engaging in recording engineering data. In October of 1958 a historic event took place, Congress transferred all of the duties of NACA to a newly formed agency called NASA, and with it came a call for systems that would keep up with new requirements. There was a need to change the type and style of equipment to keep up with the demands for more accurate information. Existing hardware was modified and new hardware was developed and designed to meet the new requirements of space travel of manned and unmanned orbital vehicles. This family of equipment had to withstand the rigors of space travel such as extremely high `G' forces, temperature changes and `O' gravity, while on earth we needed equipment to document launch of space vehicles as well as wind tunnel testing, rocket sled stands etc.. Some requirements were similar to those of launch vehicles, some were totally different and had other requirements, eventually they were all resolved. As electronic data systems became available NASA experimented with their use in data acquisition. This portion of this session will discuss the changes over the years and their effect on the acquisition of data, those that worked, as well as those that were a disappointment.

  6. Word Frequency Analysis. MOS: 75B. Skill Levels 1 & 2.

    DTIC Science & Technology

    1981-05-01

    COMMAND FORT MONROE, VIRGINIA 23651 _N -- SEP 1 W %r 4 4Ř A~ 9b AT oP 70311 0 .1 ft I.t...oI3 ~ PREPARED BY: OPERATIONS DIV. DPFOCOY...C tS ItI 2 iaL...P v 9 r 1 A e 2 G R S S 1 G ..I C E 5 2 H A N n I J N O 14EEN2 GUIDE I H ’irL ED 0 HAPPENS0 G, lu..t,CF WIAN’ 4 wk;vdt.a1rEN I HAV INtG 1 HAIDS 63M...SLED t 1 1 . 1 m/pImAt, 1 IN7RODUCTIDN 2 Issue 11 ITEPS I I T’AlSI1 I ISO 21 IyEt I 11 vi IS 1 IT’S 7 JAwI jD1P1 ŕ 11 9 IV I J’IVED-DVEj JUN z ItS

  7. Advanced instrument system for real-time and time-series microbial geochemical sampling of the deep (basaltic) crustal biosphere

    NASA Astrophysics Data System (ADS)

    Cowen, James P.; Copson, David A.; Jolly, James; Hsieh, Chih-Chiang; Lin, Huei-Ting; Glazer, Brian T.; Wheat, C. Geoffrey

    2012-03-01

    Integrated Ocean Drilling Program borehole CORK (Circulation Obviation Retrofit Kit) observatories provide long-term access to hydrothermal fluids circulating within the basaltic crust (basement), providing invaluable opportunities to study the deep biosphere. We describe the design and application parameters of the GeoMICROBE instrumented sled, an autonomous sensor and fluid sampling system. The GeoMICROBE system couples with CORK fluid delivery lines to draw large volumes of fluids from crustal aquifers to the seafloor. These fluids pass a series of in-line sensors and an in situ filtration and collection system. GeoMICROBE's major components include a primary valve manifold system, a positive displacement primary pump, sensors (e.g., fluid flow rate, temperature, dissolved O2, electrochemistry-voltammetry analyzer), a 48-port in situ filtration and fluid collection system, computerized controller, seven 24 V-40 A batteries and wet-mateable (ODI) communications with submersibles. This constantly evolving system has been successfully connected to IODP Hole 1301A on the eastern flank of the Juan de Fuca Ridge. Also described here is a mobile pumping system (MPS), which possesses many of the same components as the GeoMICROBE (e.g., pump, sensors, controller), but is directly powered and controlled in real time via submersible operations; the MPS has been employed repeatedly to collect pristine basement fluids for a variety of geochemical and microbial studies.

  8. Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft. Volume 2: Data from seat testing

    NASA Technical Reports Server (NTRS)

    Shane, S. J.

    1985-01-01

    The unacceptably high injury rate during the escape sequence (including the ejection and ground impact) of the crew module for F/FB-111 aircraft is reviewed. A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is presented. An energy absorbing test seat is designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions is conducted at a sled test facility. Comparative tests with operational F-111 crewseats are also conducted. After successful dynamic testing of the seat, more testing is conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests are conducted. The vertical drop tests are used to obtain comparative data between the energy absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series. Volume 2 presents the data obtained during the seat test series, while Volume 3 presents the data from the crew module test series.

  9. 500 MW X-BAND RF SYSTEM OF A 0.25 GEV ELECTRON LINAC FOR ADVANCED COMPTON SCATTERING SOURCE APPLICATION

    SciTech Connect

    Chu, T S; Anderson, S G; Gibson, D J; Hartemann, F V; Marsh, R A; Siders, C; Barty, C P; Adolphsen, C; Jongewaard, E; Tantawi, S; Vlieks, A; Wang, J W; Raubenheimer, T

    2010-05-12

    A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with SLAC National Accelerator Laboratory. The electron beam for the Compton scattering interaction will be generated by a X-band RF gun and a X-band LINAC at the frequency of 11.424 GHz. High power RF in excess of 500 MW is needed to accelerate the electrons to energy of 250 MeV or greater for the interaction. Two high power klystron amplifiers, each capable of generating 50 MW, 1.5 msec pulses, will be the main high power RF sources for the system. These klystrons will be powered by state of the art solid-state high voltage modulators. A RF pulse compressor, similar to the SLED II pulse compressor, will compress the klystron output pulse with a power gain factor of five. For compactness consideration, we are looking at a folded waveguide setup. This will give us 500 MW at output of the compressor. The compressed pulse will then be distributed to the RF gun and to six traveling wave accelerator sections. Phase and amplitude control are located at the RF gun input and additional control points along the LINAC to allow for parameter control during operation. This high power RF system is being designed and constructed. In this paper, we will present the design, layout, and status of this RF system.

  10. 500 MW X-Band RF System of a 0.25 GeV Electron LINAC for Advanced Compton Scattering Source Application

    SciTech Connect

    Chu, Tak Sum; Anderson, Scott; Barty, Christopher; Gibson, David; Hartemann, Fred; Marsh, Roark; Siders, Craig; Adolphsen, Chris; Jongewaard, Erik; Raubenheimer, Tor; Tantawi, Sami; Vlieks, Arnold; Wang, Juwen; /SLAC

    2012-07-03

    A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with the SLAC National Accelerator Laboratory. The electron beam for the Compton scattering interaction will be generated by a X-band RF gun and a X-band LINAC at the frequency of 11.424 GHz. High power RF in excess of 500 MW is needed to accelerate the electrons to energy of 250 MeV or greater for the interaction. Two high power klystron amplifiers, each capable of generating 50 MW, 1.5 msec pulses, will be the main high power RF sources for the system. These klystrons will be powered by state of the art solid-state high voltage modulators. A RF pulse compressor, similar to the SLED II pulse compressor, will compress the klystron output pulse with a power gain factor of five. For compactness consideration, we are looking at a folded waveguide setup. This will give us 500 MW at output of the compressor. The compressed pulse will then be distributed to the RF gun and to six traveling wave accelerator sections. Phase and amplitude control are located at the RF gun input and additional control points along the LINAC to allow for parameter control during operation. This high power RF system is being designed and constructed. In this paper, we will present the design, layout, and status of this RF system.

  11. Cross-sectional neck response of a total human body FE model during simulated frontal and side automobile impacts.

    PubMed

    White, Nicholas A; Moreno, Daniel P; Gayzik, F Scott; Stitzel, Joel D

    2015-01-01

    Human body finite element (FE) models are beginning to play a more prevalent role in the advancement of automotive safety. A methodology has been developed to evaluate neck response at multiple levels in a human body FE model during simulated automotive impacts. Three different impact scenarios were simulated: a frontal impact of a belted driver with airbag deployment, a frontal impact of a belted passenger without airbag deployment and an unbelted side impact sled test. Cross sections were created at each vertebral level of the cervical spine to calculate the force and moment contributions of different anatomical components of the neck. Adjacent level axial force ratios varied between 0.74 and 1.11 and adjacent level bending moment ratios between 0.55 and 1.15. The present technique is ideal for comparing neck forces and moments to existing injury threshold values, calculating injury criteria and for better understanding the biomechanical mechanisms of neck injury and load sharing during sub-injurious and injurious loading.

  12. a Study on the Mechanism of OCCUPANT'S Cervical Injury by Low Speed Rear-End Collision of Automobiles

    NASA Astrophysics Data System (ADS)

    Cho, Wonhak; Kim, Yongchul; Choi, Hyeonki

    Neck injury in rear-end car collisions is an increasing concern in the field of traffic safety. This injury commonly occurs at rear-end impact, however the injury mechanisms for whiplash remain a mystery. The purpose of this study is to quantitatively analyze the head and neck kinematics during the low-speed rear-end impact of automobiles. It is important to produce data that is related as closely as possible to the in vivo situation. So, we performed a sled test which simulated rear-end impacts with a velocity of 0.6 m/s with five normal healthy male subjects. 3-D motion analysis system was used to document motion data of two situations. When we compare the values of angular velocity and acceleration of head and neck, the peak magnitudes of inclined seated posture were smaller than those of upright seated posture. The result of this study is expected to provide insight that will aid in determining the mechanism of whiplash which is crucial to the identification of possible injury mechanisms.

  13. Fatal dog attacks in Canada, 1990-2007.

    PubMed

    Raghavan, Malathi

    2008-06-01

    In Canada, public debates on dog attacks are dominated by studies from the United States. An electronic search of media reports in the Canadian Newsstand database, for the years 1990 to 2007, identified 28 fatalities from dog-bite injuries. Predominant factors in this case series were owned, known dogs; residential location; children's unsupervised access to area with dogs; and rural/remote areas, including aboriginal reserves in the prairies. A higher proportion of sled dogs and, possibly, mixed-breed dogs in Canada than in the United States caused fatalities, as did multiple dogs rather than single dogs. Free-roaming dog packs, reported only from rural communities, caused most on-reserve fatalities. Future studies are needed to assess if this rural/urban divide is observed in nonfatal attacks and if the breeds that bite in Canada are different from the breeds that killed. Breed representation in this paper and, perhaps, multiple-dog overrepresentation should be understood in the context of the overall Canadian dog population.

  14. An integrated helmet and neck support (iHANS) for racing car drivers: a biomechanical feasibility study.

    PubMed

    Newman, James A; Withnall, Christopher; Wonnacott, Michael

    2012-10-01

    A new form of head and neck protection for racing car drivers is examined. The concept is one whereby the helmet portion of the system is attached, by way of a quick release clamp, to a collar-like platform which is supported on the driver's shoulders. The collar, which encircles the back and sides of the driver's neck, is held in place by way of the on-board restraint belts. The interior of the helmet portion of the assembly is large enough to provide adequate volitional head motion. The overall objective of the design is to remove the helmet from the wearer's head and thereby to mitigate the deleterious features of helmet wearing such as neck fatigue, poor ventilation and aerodynamic buffeting. Just as importantly, by transferring the weight of the helmet and all attendant reaction forces associated with inertial and impact loads to the shoulder complex (instead of to the neck), reduced head and neck injury probability should be achievable. This paper describes the concept development and the evolution of various prototype designs. Prototypes have been evaluated on track and sled tested in accordance with contemporary head neck restraint systems practice. Also discussed is a series of direct impact tests. In addition, low mass high velocity ballistic tests have been conducted and are reviewed herein. It is concluded that this new concept indeed does address most of the drawbacks of the customary helmet and that it generally can reduce the probability of head and neck injury.

  15. Comparison Between THOR Anthropomorphic Test Device and THOR Finite Element Model

    NASA Technical Reports Server (NTRS)

    Moore, Erik

    2014-01-01

    Extended time spent in reduced gravity can cause physiologic deconditioning of astronauts, reducing their ability to sustain excessive forces during dynamic phases of spaceflight such as landing. To make certain that the crew is safe during these phases, NASA must take caution when determining what types of landings are acceptable based on the accelerations applied to the astronaut. In order to test acceptable landings, various trials have been run accelerating humans, cadavers, and Anthropomorphic Test Devices (ATDs), or crash test dummies, at different acceleration and velocity rates on a sled testing platform. Using these tests, risks of injury will be created and metrics will be developed for the likelihood of injuries due to the acceleration. A finite element model (FEM) of the Test Device for Human Occupant Restraint (THOR) ATD has been developed that can simulate these test trials and others (Putnam, 2014), reducing the need for human and ATD testing. Additionally, this will give researchers a more effective way to test the accelerations and orientations encountered during spaceflight landings during design of new space vehicles for crewed missions. However, the FEM has not been proven and must be validated by comparing the forces, accelerations, and other measurements of all parts of the body between the physical tests already completed and computer simulated trials. The purpose of my research was to validate the FEM for the ATD using previously run trials with the physical THOR ATD.

  16. Using multiple markers to elucidate the ancient, historical and modern relationships among North American Arctic dog breeds

    PubMed Central

    Brown, S K; Darwent, C M; Wictum, E J; Sacks, B N

    2015-01-01

    Throughout most of the Americas, post-colonial dogs largely erased the genetic signatures of pre-historical dogs. However, the North American Arctic harbors dogs that are potentially descended from pre-historical ancestors, as well as those affected by post-colonial translocations and admixtures. In particular, Inuit dogs from Canada and Greenland are thought to descend from dogs associated with Thule peoples, who relied on them for transportation ca. 1000 years ago. Whether Thule dogs reflected an earlier colonization by Paleoeskimo dogs ca. 4500 years ago is unknown. During the Alaskan Gold Rush, additional sled dogs, possibly of post-colonial derivation, the Alaskan Husky, Malamute and Siberian Husky, were used in the Arctic. The genealogical relationships among and origins of these breeds are unknown. Here we use autosomal, paternal and maternal DNA markers to (1) test the hypothesis that Inuit dogs have retained their indigenous ancestry, (2) characterize their relationship to one another and to other Arctic breeds, and (3) estimate the age of North American indigenous matrilines and patrilines. On the basis of the agreement of all three markers we determined that Inuit dogs have maintained their indigenous nature, and that they likely derive from Thule dogs. In addition, we provide support for previous research that the Inuit dogs from Canada and Greenland dog should not be distinguished as two breeds. The Alaskan Husky displayed evidence of European introgression, in contrast to the Malamute and Siberian Husky, which appear to have maintained most of their ancient Siberian ancestry. PMID:26103948

  17. HEGRS: Mechanical design of a high-energy, gamma-ray spectrometer

    SciTech Connect

    Pedersen, K.B.

    1993-06-04

    A large, 3200-kg (7000-lb) gamma-ray spectrometer was designed to move in a 1500 arc with an arc accuracy of 0.50, and to move radially over a distance of 650 mm (25 in.). The entire structure is aluminum rather than steel because of the high neutron background. The two-layer support accommodates rapid, accurate positioning of the spectrometer in both the rotational and radial directions within 0.1 mm (0.004 in.). All movements and positioning are computer-controlled. The centerline deviation over the entire surface is 0.25 mm (0.0100 in.). The bottom layer, called the table, permits arc motion. The table is a baseplate consisting of two 3.6-m {times} 1.2-m (12-ft {times} 4-ft) cast-aluminum jig plates. The top layer, called the sled, is an aluminum plate 2.12-m {times} 1.22-m (83.38-in. {times} 48-in.) wide, which provides for radial motion. Due to the large mass of the spectrometer and the accurate positioning required, air pads are used to facilitate movement. Hydraulic brakes are applied when the detector is in its rest position to comply with the seismic requirements of the installation.

  18. Closure Report for Corrective Action Unit 425: Area 9 Main Lake Construction Debris Disposal Area, Tonopah Test Range, Nevada

    SciTech Connect

    K. B. Campbell

    2003-03-01

    Corrective Action Unit (CAU) 425 is located on the Tonopah Test Range, approximately 386 kilometers (240 miles) northwest of Las Vegas, Nevada. CAU 425 is listed in the Federal Facility Agreement and Consent Order (FFACO, 1996) and is comprised of one Corrective Action Site (CAS). CAS 09-08-001-TA09 consisted of a large pile of concrete rubble from the original Hard Target and construction debris associated with the Tornado Rocket Sled Tests. CAU 425 was closed in accordance with the FFACO and the Nevada Division of Environmental Protection-approved Streamlined Approach for Environmental Restoration Plan for CAU 425: Area 9 Main Lake Construction Debris Disposal Area, Tonopah Test Range, Nevada (U.S. Department of Energy, Nevada Operations Office, 2002). CAU 425 was closed by implementing the following corrective actions: The approved corrective action for this unit was clean closure. Closure activities included: (1) Removal of all the debris from the site. (2) Weighing each load of debris leaving the job site. (3) Transporting the debris to the U.S. Air Force Construction Landfill for disposal. (4) Placing the radioactive material in a U.S. Department of Transportation approved container for proper transport and disposal. (5) Transporting the radioactive material to the Nevada Test Site for disposal. (6) Regrading the job site to its approximate original contours/elevation.

  19. Windfield and trajectory models for tornado-propelled objects. Final report

    SciTech Connect

    Redmann, G.H.; Radbill, J.R.; Marte, J.E.; Dergarabedian, P.; Fendell, F.E.

    1983-03-01

    This is the final report of a three-phased research project to develop a six-degree-of-freedom mathematical model to predict the trajectories of tornado-propelled objects. The model is based on the meteorological, aerodynamic, and dynamic processes that govern the trajectories of missiles in a tornadic windfield. The aerodynamic coefficients for the postulated missiles were obtained from full-scale wind tunnel tests on a 12-inch pipe and car and from drop tests. Rocket sled tests were run whereby the 12-inch pipe and car were injected into a worst-case tornado windfield in order to verify the trajectory model. To simplify and facilitate the use of the trajectory model for design applications without having to run the computer program, this report gives the trajectory data for NRC-postulated missiles in tables based on given variables of initial conditions of injection and tornado windfield. Complete descriptions of the tornado windfield and trajectory models are presented. The trajectory model computer program is also included for those desiring to perform trajectory or sensitivity analyses beyond those included in the report or for those wishing to examine other missiles and use other variables.

  20. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 425: Area 9 Main Lake Construction Debris Disposal Area, Tonopah Test Range, Nevada

    SciTech Connect

    K. B. Campbell

    2002-04-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure of Corrective Action Unit (CAU) 425, Area 9 Main Lake Construction Debris Disposal Area. This CAU is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO, 1996). This site will be cleaned up under the SAFER process since the volume of waste exceeds the 23 cubic meters (m{sup 3}) (30 cubic yards [yd{sup 3}]) limit established for housekeeping sites. CAU 425 is located on the Tonopah Test Range (TTR) and consists of one Corrective Action Site (CAS) 09-08-001-TA09, Construction Debris Disposal Area (Figure 1). CAS 09-08-001-TA09 is an area that was used to collect debris from various projects in and around Area 9. The site is located approximately 81 meters (m) (265 feet [ft]) north of Edwards Freeway northeast of Main Lake on the TTR. The site is composed of concrete slabs with metal infrastructure, metal rebar, wooden telephone poles, and concrete rubble from the Hard Target and early Tornado Rocket sled tests. Other items such as wood scraps, plastic pipes, soil, and miscellaneous nonhazardous items have also been identified in the debris pile. It is estimated that this site contains approximately 2280 m{sup 3} (3000 yd{sup 3}) of construction-related debris.

  1. A parametric study of a side airbag system to meet deflection based criteria.

    PubMed

    Håland, Y; Pipkorn, B

    1996-08-01

    A side airbag system comprising of 12 liter bag to cover the BioSid chest and the abdomen down to the arm rest level, and 75 mm of padding to cover the pelvic/thigh area was evaluated by a series of sled tests at two different velocities, 10 m/s and 12 m/s. The initial bag (over) pressure was varied from 0 to 80 kPa and the bag ventilation area was varied from zero to 1500 mm2. Compressed air was used to fill the bag. It was found that the ventilation of the bag reduced the maximum chest deflection by 30 percent and the maximum viscous criterion, VC, by 50 percent (comparison was made with the same bag without ventilation). A suitable initial bag (over) pressure was found to be about 50 kPa, when the loading of the abdomen was also taken into consideration. The results indicate that the chest deflection is proportioned to the door average velocity (during the first 20 ms of deflection) to the power of about 2 and that the VC is proportional to the same velocity to the power of about 4. It was also found that a 12 liter ventilated side airbag resulted in 30-40 percent lower chest deflection and about 60 percent lower VC than 50 mm of chest padding (Ethafoam 220).

  2. The Clock Is Ticking

    NASA Technical Reports Server (NTRS)

    Gundo, Dan

    2003-01-01

    Recently, I worked on creating a one-of-a-kind device for a Space Station group studying exercise physiology at another NASA Center. They approached my department at Ames Research Center to design and build an exercise bed that allowed users to perform the motions that they needed for ground-based research. The real challenge was that they needed the device designed, built, and delivered in just one month. The bed was intended to simulate doing squats while in a horizontal position as if on a moving sled. They wanted to incorporate a resistant device called an Interim Resistive Exercise Device (IRED), an adjustable cable tied into a reel to provide a measured amount of resistance. This device was used on the Station for exercising in space; we were taking the same resistant reel and incorporating it in this bed. In the early stages of a design project, I communicate with a customer as much as I can and as often as they will tolerate. There s a lot of learning that needs to go on, and I prefer to spend a little bit of extra time here because that can save a lot of time later. In the beginning, you need to volley the information back-and-forth, so that you understand the customer s requirements and they know what you re capable of doing.

  3. Performance of Booster Seats in Side Impacts: Effect of Adjacent Passengers and Isofix Attachment

    PubMed Central

    Charlton, Judith L.; Fildes, Brian; Taranto, David; Laemmle, Ronald; Smith, Stuart; Clark, Anthony; Holden, GM

    2007-01-01

    This study examined the performance of a booster seat in different seating configurations in side-impact hyGe sled tests (crash severity 30 km/h) with two attachment systems: a standard seatbelt and ISOfix (rigid). The objectives of the study were twofold: (i) to identify the relative benefits of ISOfix attachment compared with seatbelt attachment of a near-side booster seat in a 3-abreast seating configuration with adjacent occupants in child restraints (CRS); and (ii) to examine the effects of 3-abreast seating configurations compared with no adjacent passengers on booster seat crash protection characteristics. Overall, the findings confirmed the superior performance of the rigid anchorages in reducing lateral motion of the booster as well as the two adjacent CRS. However, the expected benefits of the rigid attachment in reducing head accelerations were not uniformly observed across the three occupants/seating positions and also appeared to be influenced by seating configuration (3-abreast versus no adjacent occupant). Further research is warranted to explore the applicability of the findings for different CRS types and seating configurations. PMID:18184490

  4. Magnetic levitation systems for future aeronautics and space research and missions

    SciTech Connect

    Blankson, I.M.; Mankins, J.C.

    1996-02-01

    The objectives, advantages, and research needs for several applications of superconducting magnetic levitation to aerodynamics research, testing, and space-launch are discussed. Applications include very large-scale magnetic balance and suspension systems for high alpha testing, support interference-free testing of slender hypersonic propulsion/airframe integrated vehicles, and hypersonic maglev. Current practice and concepts are outlined as part of a unified effort in high magnetic fields R&D within NASA. Recent advances in the design and construction of the proposed ground-based Holloman test track (rocket sled) that uses magnetic levitation are presented. It is projected that ground speeds of up to Mach 8 to 11 at sea-level are possible with such a system. This capability may enable supersonic combustor tests as well as ramjet-to-scramjet transition simulation to be performed in clean air. Finally a novel space launch concept (Maglifter) which uses magnetic levitation and propulsion for a re-usable `first stage` and rocket or air-breathing combined-cycle propulsion for its second stage is discussed in detail. Performance of this concept is compared with conventional advanced launch systems and a preliminary concept for a subscale system demonstration is presented.

  5. A 12 GHz RF Power Source for the CLIC Study

    SciTech Connect

    Schirm, Karl; Curt, Stephane; Dobert, Steffen; McMonagle, Gerard; Rossat, Ghislain; Syratchev, Igor; Timeo, Luca; Haase, Andrew Jensen, Aaron; Jongewaard, Erik; Nantista, Christopher; Sprehn, Daryl; Vlieks, Arnold; Hamdi, Abdallah; Peauger, Franck; Kuzikov, Sergey; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

    2012-07-03

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  6. Dynamics of the human linear vestibulo-ocular reflex at medium frequency and modification by short-term training

    NASA Technical Reports Server (NTRS)

    Shelhamer, M.; Roberts, D. C.; Zee, D. S.

    2000-01-01

    We study here the effect of a short-term training paradigm on the gain and phase of the human translational VOR (the linear VOR: LVOR). Subjects were exposed to lateral sinusoidal translations on a sled, at 0.5 Hz, 0.3 g peak acceleration. With subjects tracking a remembered target at 1.2 m, the LVOR (slow-phase) under these conditions typically has a phase lead or lag, and a gain that falls short of compensatory. To induce short-term adaptation (training), we presented an earth-fixed visual scene at 1.2 m during sinusoidal translation (x 1 viewing) for 20 minutes, so as to drive the LVOR toward compensatory phase and gain. We examined both the slow-phase and the saccadic responses to these stimuli. Testing after training showed changes in slow-component gain and phase which were mostly but not always in the compensatory direction. These changes were more consistent in naive subjects than in subjects who had previous LVOR experience. Changes in gain were seen with step as well as sinusoidal test stimuli; gain changes were not correlated with vergence changes. There was a strong correlation between gain changes and phase changes across subjects. Fast phases (catch-up saccades) formed a large component of the LVOR under our testing conditions (approximately 30% of the changes in gain but not in phase due to training.

  7. Endoscopic Functional Fourier Domain Common Path Optical Coherence Tomography for Microsurgery

    PubMed Central

    Kang, Jin U.; Han, Jae-Ho; Liu, Xuan; Zhang, Kang; Song, Chul Gyu; Gehlbach, Peter

    2012-01-01

    A single-arm interferometer based optical coherence tomography (OCT) system known as common-path OCT (CPOCT) is rapidly progressing towards practical application. Due in part to the simplicity and robustness of its design, Fourier Domain CPOCT (FD-CP-OCT) offers advantages in many endoscopic sensing and imaging applications. FD-CP-OCT uses simple, interchangeable fiber optic probes that are easily integrated into small and delicate surgical tools. The system is capable of providing not only high resolution imaging but also optical sensing. Here, we report progress towards practical application of FD-CP-OCT in the setting of delicate microsurgical procedures such as intraocular retinal surgery. To meet the challenges presented by the microsurgical requirements of these procedures, we have developed and initiated the validation of applicable fiber optic probes. By integrating these probes into our developing imaging system, we have obtained high resolution OCT images and have also completed a demonstration of their potential sensing capabilities. Specifically, we utilize multiple SLEDs to demonstrate sub 3-micron axial resolution in water; we propose a technique to quantitatively evaluate the spatial distribution of oxygen saturation levels in tissue; and we present evidence supportive of the technology’s surface sensing and tool guidance potential by demonstrating topological and motion compensation capabilities. PMID:22899880

  8. Advanced RF power sources for linacs

    SciTech Connect

    Wilson, P.B.

    1996-10-01

    In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

  9. Relationships between ground reaction impulse and sprint acceleration performance in team sport athletes.

    PubMed

    Kawamori, Naoki; Nosaka, Kazunori; Newton, Robert U

    2013-03-01

    Large horizontal acceleration in short sprints is a critical performance parameter for many team sport athletes. It is often stated that producing large horizontal impulse at each ground contact is essential for high short sprint performance, but the optimal pattern of horizontal and vertical impulses is not well understood, especially when the sprints are initiated from a standing start. This study was an investigation of the relationships between ground reaction impulses and sprint acceleration performance from a standing start in team sport athletes. Thirty physically active young men with team sport background performed 10-m sprint from a standing start, whereas sprint time and ground reaction forces were recorded during the first ground contact and at 8 m from the start. Associations between sprint time and ground reaction impulses (normalized to body mass) were determined by a Pearson's correlation coefficient (r) analysis. The 10-m sprint time was significantly (p < 0.01) correlated with net horizontal impulse (r = -0.52) and propulsive impulse (r = -0.66) measured at 8 m from the start. No significant correlations were found between sprint time and impulses recorded during the first ground contact after the start. These results suggest that applying ground reaction impulse in a more horizontal direction is important for sprint acceleration from a standing start. This is consistent with the hypothesis of training to increase net horizontal impulse production using sled towing or using elastic resistance devices, which needs to be validated by future longitudinal training studies.

  10. Long Duration Richtmyer-Meshkov Instability Experiments

    NASA Technical Reports Server (NTRS)

    Niederhaus, Charles; Hunyadi, Sarah; Jacobs, Jeffrey

    2003-01-01

    This experimental study investigates the Richtmyer-Meshkov (RM) instability of an interface between incompressible, miscible liquids with an initial 2-D sinusoidal perturbation. The experiments are conducted in NASA Glenn Research Center's 2.2 Second Drop Tower. The experimental rig is isolated from aerodynamic drag by a surrounding drag shield. The rig falls 7 1/2 inches relative to the drag shield during the 79 ft fall of the system. An internal spring-driven sled impacting a clay ball provides the impulsive acceleration while the package is at the top of the drop tower, with the package timed to release just after the impulsive acceleration is complete. The instability evolves for 2.2 seconds until the package impacts an air bag at the bottom of the drop tower. The increased duration of these experiments provides for more than twice the observation time of the RM instability in the non-linear regime that will allow for better experimental comparison with asymptotic theories of perturbation amplitude and velocity.

  11. Design, integration, and testing of a compact FBG interrogator, based on an AWG spectrometer

    NASA Astrophysics Data System (ADS)

    Trita, Andrea; Vickers, Garrie; Mayordomo, Iker; van Thourhout, Dries; Vermeiren, Jan

    2014-05-01

    Fiber Bragg Grating or FBG sensors are gaining more and more interest in structural health monitoring of composite materials. Often, the weakest point in such a system is the ingress point of the fiber sensing chain into the composite material. For this reason we have developed a strongly miniaturized FBG interrogator unit with wireless power and data transmission, which can be incorporated in the composite structure. The interrogator is based on an arrayed waveguide grating (AWG) filter fabricated in a SOI technology, which is tailored in such a way to give large cross-talk between neighboring channels. The AWG signals are read by a linear 128 pixel InGaAs array flip-chipped on top of the Photonic Circuit (PIC). The spectrometer unit is completed with a ROIC mounted on the same substrate. The SLED and remaining electronics are integrated on a small and thin substrate and surrounded by the wireless antenna. The interrogator has an overall dimension of 100 mm diameter by max 7 mm height. The power dissipation of the electronics unit is limited to 1.5 W. The unit is capable of measuring strain values as low as 5 micro-strain.

  12. Feasibility study on conducting overflight measurements of shaped sonic boom signatures using the Firebee BQM-34E RPV

    NASA Technical Reports Server (NTRS)

    Maglieri, Domenic J.; Sothcott, Victor E.; Keefer, Thomas N., Jr.

    1993-01-01

    A study was performed to determine the feasibility of establishing if a 'shaped' sonic boom signature, experimentally shown in wind tunnel models out to about 10 body lengths, will persist out to representative flight conditions of 200 to 300 body lengths. The study focuses on the use of a relatively large supersonic remotely-piloted and recoverable vehicle. Other simulation methods that may accomplish the objective are also addressed and include the use of nonrecoverable target drones, missiles, full-scale drones, very large wind tunnels, ballistic facilities, whirling-arm techniques, rocket sled tracks, and airplane nose probes. In addition, this report will also present a background on the origin of the feasibility study including a brief review of the equivalent body concept, a listing of the basic sonic boom signature characteristics and requirements, identification of candidate vehicles in terms of desirable features/availability, and vehicle characteristics including geometries, area distributions, and resulting sonic boom signatures. A program is developed that includes wind tunnel sonic boom and force models and tests for both a basic and modified vehicles and full-scale flight tests.

  13. Magnetic levitation systems for future aeronautics and space research and missions

    NASA Technical Reports Server (NTRS)

    Blankson, Isaiah M.; Mankins, John C.

    1996-01-01

    The objectives, advantages, and research needs for several applications of superconducting magnetic levitation to aerodynamics research, testing, and space-launch are discussed. Applications include very large-scale magnetic balance and suspension systems for high alpha testing, support interference-free testing of slender hypersonic propulsion/airframe integrated vehicles, and hypersonic maglev. Current practice and concepts are outlined as part of a unified effort in high magnetic fields R&D within NASA. Recent advances in the design and construction of the proposed ground-based Holloman test track (rocket sled) that uses magnetic levitation are presented. It is protected that ground speeds of up to Mach 8 to 11 at sea-level are possible with such a system. This capability may enable supersonic combustor tests as well as ramjet-to-scramjet transition simulation to be performed in clean air. Finally a novel space launch concept (Maglifter) which uses magnetic levitation and propulsion for a re-usable 'first stage' and rocket or air-breathing combined-cycle propulsion for its second stage is discussed in detail. Performance of this concept is compared with conventional advanced launch systems and a preliminary concept for a subscale system demonstration is presented.

  14. Headrest position during normal driving: implication to neck injury risk in rear crashes.

    PubMed

    Viano, D C; Gargan, M F

    1996-11-01

    The gap and relative height of headrest behind drivers were determined for 1915 vehicles approaching an intersection on a two lane road. Vehicle type and headrest adjustment were also evaluated using film of normal driving taken by the Insurance Institute for Highway Safety. Only 10% of drivers had headrests in the most favorable position to prevent neck extension during a rearend crash. 73% of cars had adjustable headrests, but only a quarter were placed in the up position. 83% of the adjustable headrests could have been raised to better protect the driver. Hyge sled tests were run to determine biomechanical responses for the various conditions observed in normal driving. This included three headrest heights and three gaps behind the head. Neck extension from the Hybrid III dummy was normalized to the response for a high, close headrest, and injury risk was assumed to be proportional to neck extension. The current driving situation has a relative injury risk of 3.4 in rearend crashes, compared to 1.0 for the favorable condition. If all adjustable headrests were placed in the up position, the relative risk would be lowered to 2.4, a 28.3% reduction in whiplash injury risk. Public education and vehicle design should address the importance of proper headrest placement for driving safety.

  15. Context-specific adaptation of the gain of the oculomotor response to lateral translation using roll and pitch head tilts as contexts

    NASA Technical Reports Server (NTRS)

    Shelhamer, Mark; Peng, Grace C Y.; Ramat, Stefano; Patel, Vivek

    2002-01-01

    Previous studies established that vestibular and oculomotor behaviors can have two adapted states (e.g., gain) simultaneously, and that a context cue (e.g., vertical eye position) can switch between the two states. The present study examined this phenomenon of context-specific adaptation for the oculomotor response to interaural translation (which we term "linear vestibulo-ocular reflex" or LVOR even though it may have extravestibular components). Subjects sat upright on a linear sled and were translated at 0.7 Hz and 0.3 gpeak acceleration while a visual-vestibular mismatch paradigm was used to adaptively increase (x2) or decrease (x0) the gain of the LVOR. In each experimental session, gain increase was asked for in one context, and gain decrease in another context. Testing in darkness with steps and sines before and after adaptation, in each context, assessed the extent to which the context itself could recall the gain state that was imposed in that context during adaptation. Two different contexts were used: head pitch (26 degrees forward and backward) and head roll (26 degrees or 45 degrees, right and left). Head roll tilt worked well as a context cue: with the head rolled to the right the LVOR could be made to have a higher gain than with the head rolled to the left. Head pitch tilt was less effective as a context cue. This suggests that the more closely related a context cue is to the response being adapted, the more effective it is.

  16. Door velocity and occupant distance affect lateral thoracic injury mitigation with side airbag.

    PubMed

    Hallman, Jason J; Yoganandan, Narayan; Pintar, Frank A

    2011-05-01

    The relationship between thoracic injury risk and parameters of door velocity and occupant distance was delineated in blunt lateral impact with side airbag deployment. A sled impact model was exercised with the validated MADYMO fiftieth percentile facet occupant model and a generalized finite element torso side airbag. Impact velocity was incremented from 4.0 to 9.0m/s; occupant-airbag distance (at time of airbag activation) was incremented from 2.0 to 24.0 cm; simulations without airbag were also examined. Using compression, deflection rate, and the Viscous Criterion, airbag performance was characterized with respect to occupant injury risk at three points of interest: occupant distance of most protection, distance of greatest injury risk, and the newly defined critical distance. The occupant distance which demonstrated the most airbag protection, i.e., lowest injury risk, increased with increasing impact velocity. Greatest injury risk resulted when the occupant was nearest the airbag regardless of impact velocity. The critical distance was defined as the farthest distance at which airbag deployment exacerbated injury risk. This critical distance only varied considering chest compression, between 3 and 10 cm from the airbag, but did not vary when the Viscous Criterion was evaluated. At impact velocities less than or equal to 6m/s, the most protective occupant location was within 2 cm of the critical distance at which the airbag became harmful. Therefore, injury mitigation with torso airbag may be more difficult to achieve at lower ΔV.

  17. Tracing the origin of Geodynamics: The Alfred Wegener Memorial Expedition 2014

    NASA Astrophysics Data System (ADS)

    Stüwe, Kurt

    2015-04-01

    2012 marked the 100st anniversary of the seminal publications on Continental Drift Theory by Alfred Wegener. These publications (and Wegener's book "On the origin of the continents", published three years later) are widely accepted to be the fundamental breakthrough that opened the path to the Theory of Plate Tectoncis and ultimately the path to modern Geodynamics some 50 years later. In the same historic year of the 1912 publications, Alfred Wegener set off for what was to become the most dramatic of his three Greenland expeditions. On this expedition Wegener and Koch crossed the entire northern icecap of Greenland. In honour of the hundreds anniversary of Wegener's publications, the Austrian Academy of Sciences funded an expedition to trace the footsteps of the 1912 expedition in the spirit of Alfred Wegener, while also conducting modern Earth Science. This expedition that was conducted in summer 2014. For the expedition, a 1952 Cessna180 was acquired in Alaska, adapted with bush wheels, wing extensions and extra tanks and was flown by the author and one of the worlds most renown bush pilots from Alaska in a 10 day effort to Greenland. There, the entire NE Greenland Caledonides were covered and photographed. Field work for a masters projects was conducted and samples were collected from a series of some of the most remote locations in the Caledonides ever visited. Most spectacularly, the original sled of Wegeners 1912 expedition was found some 30 kilometers from its expected location in the Dove Bugt Region of northeastern Greenland.

  18. Dynamics of the human linear vestibulo-ocular reflex at medium frequency and modification by short-term training.

    PubMed

    Shelhamer, M; Roberts, D C; Zee, D S

    2000-01-01

    We study here the effect of a short-term training paradigm on the gain and phase of the human translational VOR (the linear VOR: LVOR). Subjects were exposed to lateral sinusoidal translations on a sled, at 0.5 Hz, 0.3 g peak acceleration. With subjects tracking a remembered target at 1.2 m, the LVOR (slow-phase) under these conditions typically has a phase lead or lag, and a gain that falls short of compensatory. To induce short-term adaptation (training), we presented an earth-fixed visual scene at 1.2 m during sinusoidal translation (x 1 viewing) for 20 minutes, so as to drive the LVOR toward compensatory phase and gain. We examined both the slow-phase and the saccadic responses to these stimuli. Testing after training showed changes in slow-component gain and phase which were mostly but not always in the compensatory direction. These changes were more consistent in naive subjects than in subjects who had previous LVOR experience. Changes in gain were seen with step as well as sinusoidal test stimuli; gain changes were not correlated with vergence changes. There was a strong correlation between gain changes and phase changes across subjects. Fast phases (catch-up saccades) formed a large component of the LVOR under our testing conditions (approximately 30% of the changes in gain but not in phase due to training.

  19. Polymer infiltration studies

    NASA Technical Reports Server (NTRS)

    Marchello, Joseph M.

    1993-01-01

    During the past three months, significant progress has been made on the preparation of carbon fiber composites using advanced polymer resins. The results are set forth in recent reports and publications, and will be presented at forthcoming national and international meetings. Current and ongoing research activities reported herein include: textile composites from powder-coated towpreg; role of surface coating in braiding; prepregger hot sled operation; ribbonizing powder-impregenated towpreg; textile composites from powder-coated towpreg; role of bulk factor powder curtain prepreg process advanced tow placement (ATP) open-section part warpage control. During the coming months research will be directed toward further development of the new powder curtain prepregging method and on ways to customize dry powder towpreg for textile and robotic applications in aircraft part fabrication. Studies of multi-tow powder prepregging and ribbon preparation will be conducted in conjunction with continued development of prepregging technology and the various aspects of composite part fabrication using customized towpreg. Also, during the period ahead work will continue on the analysis of the performance of the new solution prepregger.

  20. 3D finite element modeling of sliding wear

    NASA Astrophysics Data System (ADS)

    Buentello Hernandez, Rodolfo G.

    Wear is defined as "the removal of material volume through some mechanical process between two surfaces". There are many mechanical situations that can induce wear and each can involve many wear mechanisms. This research focuses on the mechanical wear due to dry sliding between two surfaces. Currently there is a need to identify and compare materials that would endure sliding wear under severe conditions such as high velocities. The high costs associated with the field experimentation of systems subject to high-speed sliding, has prevented the collection of the necessary data required to fully characterize this phenomena. Simulating wear through Finite Elements (FE) would enable its prediction under different scenarios and would reduce experimentation costs. In the aerospace, automotive and weapon industries such a model can aid in material selection, design and/or testing of systems subjected to wear in bearings, gears, brakes, gun barrels, slippers, locomotive wheels, or even rocket test tracks. The 3D wear model presented in this dissertation allows one to reasonably predict high-speed sliding mechanical wear between two materials. The model predictions are reasonable, when compared against those measured on a sled slipper traveling over the Holloman High Speed Tests Track. This slipper traveled a distance of 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s.

  1. Mission planning for space based satellite surveillance experiments with the MSX

    NASA Technical Reports Server (NTRS)

    Sridharan, R.; Fishman, T.; Robinson, E.; Viggh, H.; Wiseman, A.

    1994-01-01

    The Midcourse Space Experiment is a BMDO-sponsored scientific satellite set for launch within the year. The satellite will collect phenomenology data on missile targets, plumes, earth limb backgrounds and deep space backgrounds in the LWIR, visible and ultra-violet spectral bands. It will also conduct functional demonstrations for space-based space surveillance. The Space-Based Visible sensor, built by Lincoln Laboratory, Massachusetts Institute of Technology, is the primary sensor on board the MSX for demonstration of space surveillance. The SBV Processing, Operations and Control Center (SPOCC) is the mission planning and commanding center for all space surveillance experiments using the SBV and other MSX instruments. The guiding principle in the SPOCC Mission Planning System was that all routine functions be automated. Manual analyst input should be minimal. Major concepts are: (I) A high level language, called SLED, for user interface to the system; (2) A group of independent software processes which would generally be run in a pipe-line mode for experiment commanding but can be run independently for analyst assessment; (3) An integrated experiment cost computation function that permits assessment of the feasibility of the experiment. This paper will report on the design, implementation and testing of the Mission Planning System.

  2. New technology is needed to develop Norwegian trench find

    SciTech Connect

    Fay, C.E.

    1983-01-01

    A/S NORSKE SHELL has found super giant reserves of oil and gas in Block 31/2 and adjacent blocks in the Norwegian North Sea. But development of the discovery poses staggering problems--the field lies in more than 1,000 ft of water in an area noted for violent weather. Even though conventional technology will be used wherever possible, Block 31/2 development involves severe technical and financial risk. Because of the areal extent of the reservoir and constraints on directional drilling, both template and satellite wells will be used. The choice between wireline and through flowline (TFL) servicing has not been finalized, but TFL completions seem to offer better flexibility. The choice of control systems is between the reliability inherent in completely hydraulic systems or the quick response time of electro-hydraulic controls. Underwater connections will be made without the aid of divers, possibly by using a surface-controlled sled, patterned after the one developed for the Shell Expro Cormorant UMC system. This two-part series is operator A/S Norske Shell's first official word on development of the field. Part 1 focuses upon fundamental decisions involving well location and subsea equipment. Part 2, which will be published next month, examines deepwater platform technology.

  3. Feasibility study on linear-motor-assisted take-off (LMATO) of winged launch vehicle

    NASA Astrophysics Data System (ADS)

    Nagatomo, Makoto; Kyotani, Yoshihiro

    1987-11-01

    Application of technology of magnetically levitated transportation to horizontal take-off of an experimental space vehicle has been studied. An experimental system of linear-motor-assisted take-off (LMATO) consists of the HIMES space vehicle and a magnetically levitated and propelled sled which is a modified MLU model developed by the JNR. The original MLU model is a train of three cars which weighs 30 tons and is driven by a thrust of 15 tons. The maximum speed is 400 km/h. The highest speed of 517 km/h has been obtained by the first JNR linear motor car. Since the take-off speed of the HIMES vehicle with the initial mass of 14 tons is 470 km/h, the existing technology can be used for the LMATO of the vehicle. The concept of the HIMES/LMATO is to use the MLU vehicles to accelerate the HIMES vehicle at 0.33 g on a 5 km guide track until the speed reaches 300 km/h, when the rocket engines of the space vehicle are started to increase the acceleration up to 1 g. The total system will take the final checkout for take-off during the acceleration phase and the speed exceeds 470 km/h which is large enough to aerodynamically lift the space vehicle, then the fastening mechanism is unlocked to separate the vehicles. The experimental system can be applied for initial acceleration of a vehicle with air-breathing propulsion.

  4. Design, realization and test of C-band accelerating structures for the SPARC_LAB linac energy upgrade

    NASA Astrophysics Data System (ADS)

    Alesini, D.; Bellaveglia, M.; Biagini, M. E.; Boni, R.; Brönnimann, M.; Cardelli, F.; Chimenti, P.; Clementi, R.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Ficcadenti, L.; Gallo, A.; Kalt, R.; Lollo, V.; Palumbo, L.; Piersanti, L.; Schilcher, T.

    2016-11-01

    The energy upgrade of the SPARC_LAB photo-injector at LNF-INFN (Frascati, Italy) has been originally conceived replacing one low gradient (13 MV/m) 3 m long SLAC type S-band traveling wave (TW) section with two 1.4 m long C-band accelerating sections. Due to the higher gradients reached by such structures, a higher energy beam can be obtained within the same accelerator footprint length. The use of C-band structures for electron acceleration has been adopted in a few FEL linacs in the world, among others, the Japanese Free Electron Laser at SPring-8 and the SwissFEL at Paul Scherrer Institute (PSI). The C-band sections are traveling wave, constant impedance structures with symmetric input and output axial couplers. Their design has been optimized for the operation with a SLED RF pulse compressor. In this paper we briefly review their design criteria and we focus on the construction, tuning, low and high-power RF tests. We also illustrate the design and realization of the dedicated low level RF system that has been done in collaboration with PSI in the framework of the EU TIARA project. Preliminary experimental results appear to confirm the operation of such structures with accelerating gradients larger than 35 MV/m.

  5. High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

    SciTech Connect

    Tantawi, S.G.; Nantista, C.D.; Dolgashev, V.A.; Pearson, C.; Nelson, J.; Jobe, K.; Chan, J.; Fant, K.; Frisch, J.; Atkinson, D.; /LLNL, Livermore

    2005-08-10

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  6. Microhabitat and shrimp abundance within a Norwegian cold-water coral ecosystem

    NASA Astrophysics Data System (ADS)

    Purser, A.; Ontrup, J.; Schoening, T.; Thomsen, L.; Tong, R.; Unnithan, V.; Nattkemper, T. W.

    2013-02-01

    Cold-water coral reefs are highly heterogeneous ecosystems comprising of a range of diverse microhabitats. In a typical European cold-water coral reef various biogenic habitats (live colonies of locally common coral species such as Lophelia pertusa, Paragorgia arborea and Primnoa resedaeformis, dead coral structure, coral rubble) may be surrounded and intermixed with non-biogenic habitats (soft sediment, hardground, gravel/pebbles, steep walls). To date, studies of distribution of sessile fauna across these microhabitats have been more numerous than those investigating mobile fauna distribution. In this study we quantified shrimp densities associated with key CWC habitat categories at the Røst reef, Norway, by analysing image data collected by towed video sled. We also investigated shrimp distribution patterns on the local scale (<40 cm) and how these may vary with habitat. We found shrimp abundances at the Røst reef to be on average an order of magnitude greater in biogenic reef habitats than in non-biogenic habitats. Greatest shrimp densities were observed in association with live Paragorgia arborea habitats (43 shrimp m-2, SD = 35.5), live Primnoa resedaeformis habitats (41.6 shrimp m-2, SD = 26.1) and live Lophelia pertusa habitats (24.4 shrimp m-2, SD = 18.6). In non-biogenic habitats shrimp densities were <2 shrimp m-2. We conclude that CWC reef habitats clearly support greater shrimp densities than the surrounding non-biogenic habitats on the Norwegian margin.

  7. Microhabitat and shrimp abundance within a Norwegian cold-water coral ecosystem

    NASA Astrophysics Data System (ADS)

    Purser, A.; Ontrup, J.; Schoening, T.; Thomsen, L.; Tong, R.; Unnithan, V.; Nattkemper, T. W.

    2013-09-01

    Cold-water coral (CWC) reefs are heterogeneous ecosystems comprising numerous microhabitats. A typical European CWC reef provides various biogenic microhabitats (within, on and surrounding colonies of coral species such as Lophelia pertusa, Paragorgia arborea and Primnoa resedaeformis, or formed by their remains after death). These microhabitats may be surrounded and intermixed with non-biogenic microhabitats (soft sediment, hard ground, gravel/pebbles, steep walls). To date, studies of distribution of sessile fauna across CWC reefs have been more numerous than those investigating mobile fauna distribution. In this study we quantified shrimp densities associated with key CWC microhabitat categories at the Røst Reef, Norway, by analysing image data collected by towed video sled in June 2007. We also investigated shrimp distribution patterns on the local scale (<40 cm) and how these may vary with microhabitat. Shrimp abundances at the Røst Reef were on average an order of magnitude greater in biogenic reef microhabitats than in non-biogenic microhabitats. Greatest shrimp densities were observed in association with live Paragorgia arborea microhabitat (43 shrimp m-2, SD = 35.5), live Primnoa resedaeformis microhabitat (41.6 shrimp m-2, SD = 26.1) and live Lophelia pertusa microhabitat (24.4 shrimp m-2, SD = 18.6). In non-biogenic microhabitat, shrimp densities were <2 shrimp m-2. CWC reef microhabitats appear to support greater shrimp densities than the surrounding non-biogenic microhabitats at the Røst Reef, at least at the time of survey.

  8. Transportation safety standards for wheelchair users: a review of voluntary standards for improved safety, usability, and independence of wheelchair-seated travelers.

    PubMed

    Schneider, Lawrence W; Manary, Miriam A; Hobson, Douglas A; Bertocci, Gina E

    2008-01-01

    Safe transportation for wheelchair users who do not transfer to the vehicle seat when traveling in motor vehicles requires after-market wheelchair tiedown and occupant restraint systems (WTORS) to secure the wheelchair and provide crashworthy restraint for the wheelchair-seated occupant. In the absence of adequate government safety standards, voluntary standards for the design and performance of WTORS, and for wheelchairs used as seats in motor vehicles, have been developed. The initial versions of these standards qualify equipment for use in all types and sizes of motor vehicles using a 30-mph (48-kph), 20-g frontal sled-impact test. The wheelchair standard requires four accessible, crash-tested securement points on wheelchairs so they can be more easily and effectively secured using a four-point strap-type tie-down system. Future voluntary standards are aimed at reducing injury risk for wheelchair-seated occupants in rear impacts and at providing a method for evaluating the crashworthiness of wheelchair seating systems independent of wheelchair base-frames. They also address improved usability and independence for wheelchair-seated travelers using public transportation by specifying universal docking interface geometry for wheelchairs and design and performance requirements for rear-facing wheelchair passenger stations for use in the very low-g environments of large fixed-route transit buses.

  9. Capabilities of NASA/Marshall Space Flight Center's Impact Testing Facility

    NASA Technical Reports Server (NTRS)

    Hovater, Mary; Hubbs, Whitney; Finchum, Andy; Evans, Steve; Nehls, Mary

    2006-01-01

    The Impact Testing Facility (ITF) serves as an important installation for materials science at Marshall Space Flight Center (MSFC). With an array of air, powder, and two-stage light gas guns, a variety of projectile and target types and sizes can be accommodated. The ITF allows for simulation of impactors from rain to micrometeoroids and orbital debris on materials being investigated for space, atmospheric, and ground use. Expendable, relatively simple launch assemblies are used to obtain well-documented results for impact conditions comparable to those from ballistic and rocket sled ranges at considerably lower cost. In addition, for applications requiring study of impacts at speeds in excess of those attainable by gun launches, hydrocode simulations, validated by test data, can be used to extend the velocity range. In addition to serving various NASA directorates, the ITF has performed testing on behalf of the European and Russian space agencies, as well as the Department of Defense, and academic institutions. The m s contributions not only enable safer space flight for NASA s astronauts, but can help design materials and structures to protect soldiers and civilians on Earth, through advances in body armor, aircraft survivability, and a variety of other applications.

  10. Conceptual Design and Analysis of Cold Mass Support of the CS3U Feeder for the ITER

    NASA Astrophysics Data System (ADS)

    Zhu, Yinfeng; Song, Yuntao; Zhang, Yuanbin; Wang, Zhongwei

    2013-06-01

    In the International Thermonuclear Experimental Reactor (ITER) project, the feeders are one of the most important and critical systems. To convey the power supply and the coolant for the central solenoid (CS) magnet, 6 sets of CS feeders are employed, which consist mainly of an in-cryostat feeder (ICF), a cryostat feed-through (CFT), an S-bend box (SBB), and a coil terminal box (CTB). To compensate the displacements of the internal components of the CS feeders during operation, sliding cold mass supports consisting of a sled plate, a cylindrical support, a thermal shield, and an external ring are developed. To check the strength of the developed cold mass supports of the CS3U feeder, electromagnetic analysis of the two superconducting busbars is performed by using the CATIA V5 and ANSYS codes based on parametric technology. Furthermore, the thermal-structural coupling analysis is performed based on the obtained results, except for the stress concentration, and the max. stress intensity is lower than the allowable stress of the selected material. It is found that the conceptual design of the cold mass support can satisfy the required functions under the worst case of normal working conditions. All these performed activities will provide a firm technical basis for the engineering design and development of cold mass supports.

  11. Highly Reusable Space Transportation System Concept Evaluation (The Argus Launch Vehicle)

    NASA Technical Reports Server (NTRS)

    Olds, John R.; Bellini, Peter X.

    1998-01-01

    This paper summarizes the results of a conceptual design study that was performed in support of NASA's recent Highly Reusable Space Transportation study. The Argus concept uses a Maglifter magnetic-levitation sled launch assist system to accelerate it to a takeoff ground speed of 800 fps on its way to delivering a payload of 20,000 lb. to low earth orbit. Main propulsion is provided by two supercharged ejector rocket engines. The vehicle is autonomous and is fully reusable. A conceptual design exercise determined the vehicle gross weight to be approximately 597,250 lb. and the dry weight to be 75,500 lb. Aggressive weight and operations cost assumptions were used throughout the design process consistent with a second-generation reusable system that might be deployed in 10-15 years. Drawings, geometry, and weight of the concept are included. Preliminary development, production, and operations costs along with a business scenario assuming a price-elastic payload market are also included. A fleet of three Argus launch vehicles flying a total of 149 flights per year is shown to have a financial internal rate of return of 28%. At $169/lb., the recurring cost of Argus is shown to meet the study goal of $100/lb.-$200/lb., but optimum market price results in only a factor of two to five reduction compared to today's launch systems.

  12. Ambiguous Tilt and Translation Motion Cues in Astronauts after Space Flight

    NASA Technical Reports Server (NTRS)

    Clement, G.; Harm, D. L.; Rupert, A. H.; Beaton, K. H.; Wood, S. J.

    2008-01-01

    Adaptive changes during space flight in how the brain integrates vestibular cues with visual, proprioceptive, and somatosensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions following transitions between gravity levels. This joint ESA-NASA pre- and post-flight experiment is designed to examine both the physiological basis and operational implications for disorientation and tilt-translation disturbances in astronauts following short-duration space flights. The first specific aim is to examine the effects of stimulus frequency on adaptive changes in eye movements and motion perception during independent tilt and translation motion profiles. Roll motion is provided by a variable radius centrifuge. Pitch motion is provided by NASA's Tilt-Translation Sled in which the resultant gravitoinertial vector remains aligned with the body longitudinal axis during tilt motion (referred to as the Z-axis gravitoinertial or ZAG paradigm). We hypothesize that the adaptation of otolith-mediated responses to these stimuli will have specific frequency characteristics, being greatest in the mid-frequency range where there is a crossover of tilt and translation. The second specific aim is to employ a closed-loop nulling task in which subjects are tasked to use a joystick to null-out tilt motion disturbances on these two devices. The stimuli consist of random steps or sum-of-sinusoids stimuli, including the ZAG profiles on the Tilt-Translation Sled. We hypothesize that the ability to control tilt orientation will be compromised following space flight, with increased control errors corresponding to changes in self-motion perception. The third specific aim is to evaluate how sensory substitution aids can be used to improve manual control performance. During the closed-loop nulling task on both devices, small tactors placed around the torso vibrate according to the actual body tilt angle relative to gravity. We hypothesize

  13. Variability in the control of head movements in seated humans: a link with whiplash injuries?

    PubMed Central

    Vibert, N; MacDougall, H G; de Waele, C; Gilchrist, D P D; Burgess, A M; Sidis, A; Migliaccio, A; Curthoys, I S; Vidal, P P

    2001-01-01

    The aim of this study was to determine how context and on-line sensory information are combined to control posture in seated subjects submitted to high-jerk, passive linear accelerations. Subjects were seated with eyes closed on a servo-controlled linear sled. They were asked to relax and received brief accelerations either sideways or in the fore-aft direction. The stimuli had an abrupt onset, comparable to the jerk experienced during a minor car collision. Rotation and translation of the head and body were measured using an Optotrak system. In some of the subjects, surface electromyographic (EMG) responses of selected neck and/or back muscles were recorded simultaneously. For each subject, responses were highly stereotyped from the first trial, and showed little sign of habituation or sensitisation. Comparable results were obtained with sideways and fore-aft accelerations. During each impulse, the head lagged behind the trunk for several tens of milliseconds. The subjects' head movement responses were distributed as a continuum in between two extreme categories. The ‘stiff’ subjects showed little rotation or translation of the head relative to the trunk for the whole duration of the impulse. In contrast, the ‘floppy’ subjects showed a large roll or pitch of the head relative to the trunk in the direction opposite to the sled movement. This response appeared as an exaggerated ‘inertial’ response to the impulse. Surface EMG recordings showed that most of the stiff subjects were not contracting their superficial neck or back muscles. We think they relied on bilateral contractions of their deep, axial musculature to keep the head-neck ensemble in line with the trunk during the movement. About half of the floppy subjects displayed reflex activation of the neck muscles on the side opposite to the direction of acceleration, which occurred before or during the head movement and tended to exaggerate it. The other floppy subjects seemed to rely on only the

  14. Feasibility Study of a Lunar Analog Bed Rest Model

    NASA Technical Reports Server (NTRS)

    Cromwell, Ronita L.; Platts, Steven H.; Yarbough, Patrice; Buccello-Stout, Regina

    2010-01-01

    The purpose of this study was to determine the feasibility of using a 9.5deg head-up tilt bed rest model to simulate the effects of the 1/6 g load to the human body that exists on the lunar surface. The lunar analog bed rest model utilized a modified hospital bed. The modifications included mounting the mattress on a sled that rolled on bearings to provide freedom of movement. The weight of the sled was off-loaded using a counterweight system to insure that 1/6 body weight was applied along the long axis (z-axis) of the body. Force was verified through use of a force plate mounted at the foot of the bed. A seating assembly was added to the bed to permit periods of sitting. Subjects alternated between standing and sitting positions throughout the day. A total of 35% of the day was spent in the standing position and 65% was spent sitting. In an effort to achieve physiologic fluid shifts expected for a 1/6 G environment, subjects wore compression stockings and performed unloaded foot and ankle exercises. Eight subjects (3 females and 5 males) participated in this study. Subjects spent 13 days in the pre-bed rest phase, 6 days in bed rest and 3 days post bed rest. Subjects consumed a standardized diet throughout the study. To determine feasibility, measures of subject comfort, force and plasma volume were collected. Subject comfort was assessed using a Likert scale. Subjects were asked to assess level of comfort (0-100) for 11 body regions and provide an overall rating. Results indicated minimal to no discomfort as most subjects reported scores of zero. Force measures were performed for each standing position and were validated against subject s calculated 1/6 body weight (r(sup 2) = 0.993). The carbon monoxide rebreathing technique was used to assess plasma volume during pre-bed rest and on the last day of bed rest. Plasma volume results indicated a significant decrease (p = 0.001) from pre to post bed rest values. Subjects lost on average 8.3% (sd = 6.1%) during the

  15. A Fine-Resolution Radar for Mapping Near-Surface Isochronous Layers

    NASA Astrophysics Data System (ADS)

    Rink, T. P.; Kanagaratnam, P.; Braaten, D.; Zimmerman, K.; Akins, T.; Gogineni, S.

    2005-12-01

    Information on the spatial and temporal variation of snow accumulation is required for interpreting satellite-based radar and laser surface elevation measurements made by CryoSAT and ICESAT altimeters. Current methods of using ice cores and analyzing snow pit stratigraphy is time consuming and prone to errors in spatial representation due to the sparse sampling. Remote sensing methods that can map near-surface internal layers for estimating spatial and temporal variation are required. To accomplish this, we developed a 12-18 GHz FMCW radar to map near-surface layers with 3 cm vertical resolution to a depth of about 10 m. We developed the system to be mobile and self-contained so that spatial variability of the accumulation over a large area can be characterized. The fine resolution of this radar is achieved by its wide bandwidth and by illuminating the target area with a plane-wave, which is implemented using an offset-fed parabolic reflector. Traditional wide-beamwidth antennas are susceptible to spherical wave scattering from off-vertical targets that can potentially mask weaker reflections from internal layers. The radar features a fast transmit waveform synthesizer implemented using a voltage controlled oscillator (VCO) and a phase-locked loop (PLL) using a linear chirp as the reference. The highly linear reference chirp was generated by a direct digital synthesis (DDS) waveform generator and compared against the instantaneous output of the VCO to create a highly linear 12 to 18 GHz transmit chirp. The waveform synthesizer can be swept from 12 to 18 GHz in 500 microseconds. The antenna was mounted on a sled and the radar system was integrated with the antenna feed. We designed and built the sled with a gimbaled antenna mount and sensing control system to ensure that the antenna points at nadir. The radar system was successfully tested at the Summit camp, Greenland, in July 2005. We collected a large amount of data from various locations around Summit camp. The

  16. Archive of side scan sonar and swath bathymetry data collected during USGS cruise 10CCT01 offshore of Cat Island, Gulf Islands National Seashore, Mississippi, March 2010

    USGS Publications Warehouse

    DeWitt, Nancy T.; Flocks, James G.; Pfeiffer, William R.; Wiese, Dana S.

    2010-01-01

    activity for that project in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the field activity ID. Data were collected using a 26-foot (ft) Glacier Bay Catamaran. Side scan sonar and interferometric swath bathymetry data were collected simultaneously along the tracklines. The side scan sonar towfish was towed off the port side just slightly behind the vessel, close to the seafloor. The interferometric swath transducer was sled-mounted on a rail attached between the catamaran hulls. During the survey the sled is secured into position. Navigation was acquired with a CodaOctopus Octopus F190 Precision Attitude and Positioning System and differentially corrected with OmniSTAR. See the digital FACS equipment log for details about the acquisition equipment used. Both raw datasets were stored digitally and processed using CARIS HIPS and SIPS software at the USGS St. Petersburg Coastal and Marine Science Center. For more information on processing refer to the Equipment and Processing page. Post-processing of the swath dataset revealed a motion artifact that is attributed to movement of the pole that the swath transducers are attached to in relation to the boat. The survey took place in the winter months, in which strong winds and rough waves contributed to a reduction in data quality. The rough seas contributed to both the movement of the pole and the very high noise base seen in the raw amplitude data of the side scan sonar. Chirp data were also collected during this survey and are archived separately.

  17. Biological investigations of the Sandia National Laboratories Sol se Mete Aerial Cable Facility

    SciTech Connect

    Sullivan, R.M.

    1994-10-01

    This report provides results of a comprehensive biological field survey performed on the Sandia National Laboratories Aerial Cable Facility, at the east end of Kirtland Air Force Base (KAFB), Bernalillo County, New Mexico. This survey was conducted late September through October, 1991. ACF occupies a 440-acre tract of land withdrawn by the US Forest Service (USFS) for use by KAFB, and in turn placed under operational control of SNL by the Department of Energy (DOE). All land used by SNL for ACF is part of a 15,851-acre tract of land withdrawn by the US Forest Service. In addition, a number of different organizations use the 15,851-acre area. The project area used by SNL encompasses portions of approximately six sections (3,840 acres) of US Forest Service land located within the foothills of the west side of the Manzano Mountains (East Mesa). The biological study area is used by the KAFB, the US Department of Interior, and SNL. This area includes: (1) Sol se Mete Springs and Canyon, (2) East Anchor Access Road, (3) East Anchor Site, (4) Rocket Sled Track, (5) North Arena, (6) East Instrumentation Site and Access Road, (7) West Anchor Access Road, (8) West Anchor Site, (9) South Arena, (10) Winch Sites, (11) West Instrumentation Sites, (12) Explosive Assembly Building, (13) Control Building, (14) Lurance Canyon Road and vicinity. Although portions of approximately 960 acres of withdrawn US Forest Service land have been altered, only 700 acres have been disturbed by activities associated with ACF; approximately 2,880 acres consist of natural habitat. Absence of grazing by livestock and possibly native ungulates, and relative lack of human disturbance have allowed this area to remain in a more natural vegetative state relative to the condition of private range lands throughout New Mexico. This report evaluates threatened and endangered species found on ACF, as well as a comprehensive assessment of biological habitats.

  18. L'CO/LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive

    NASA Technical Reports Server (NTRS)

    Kamenetzky, J.; Rangwala, N.; Glenn, J.; Maloney, P. R.; Conley, A.

    2015-01-01

    We present a catalog of all CO (carbon monoxide) (J (total angular momentum quantum number) equals 1-0 through J equals 13-12), [CI], and [NII] lines available from extragalactic spectra from the Herschel SPIRE (Spectral and Photometric Imaging Receiver) Fourier Transform Spectrometer (FTS) archive combined with observations of the low-J CO lines from the literature and from the Arizona Radio Observatory. This work examines the relationships between L (sub FIR (Far Infra Red)), L prime (sub CO), and L (sub CO) / L (sub CO, 1-0). We also present a new method for estimating probability distribution functions (PDFs) from marginal signal-to-noise ratio Herschel FTS spectra, which takes into account the instrumental "ringing" and the resulting highly correlated nature of the spectra. The slopes of Log (L (sub FIR)) versus Log (L prime (sub CO)) are linear for all mid- to high-J CO lines. The mid- to high-J CO luminosity relative to CO J equals 1-0 increases with increasing L (sub FIR), indicating higher excitement of the molecular gas, though these ratios do not exceed approximately 100. The luminosities relative to CO J equals 1-0 remain relatively at from J equals 6-5 through J equals13-2, across many orders of magnitude of L (sub FIR). Qualitative comparisons to current theoretical models do not match these flat SLED (spectral line energy distributions) shapes, indicating the need for more comprehensive modeling of the excitation processes of warm molecular gas in nearby galaxies.

  19. The effects of resisted sprint training on acceleration performance and kinematics in soccer, rugby union, and Australian football players.

    PubMed

    Spinks, Christopher D; Murphy, Aron J; Spinks, Warwick L; Lockie, Robert G

    2007-02-01

    Acceleration is a significant feature of game-deciding situations in the various codes of football. However little is known about the acceleration characteristics of football players, the effects of acceleration training, or the effectiveness of different training modalities. This study examined the effects of resisted sprint (RS) training (weighted sled towing) on acceleration performance (0-15 m), leg power (countermovement jump [CMJ], 5-bound test [5BT], and 50-cm drop jump [50DJ]), gait (foot contact time, stride length, stride frequency, step length, and flight time), and joint (shoulder, elbow, hip, and knee) kinematics in men (N = 30) currently playing soccer, rugby union, or Australian football. Gait and kinematic measurements were derived from the first and second strides of an acceleration effort. Participants were randomly assigned to 1 of 3 treatment conditions: (a) 8-week sprint training of two 1-h sessions x wk(-1) plus RS training (RS group, n = 10), (b) 8-week nonresisted sprint training program of two 1-h sessions x wk(-1) (NRS group, n = 10), or (c) control (n = 10). The results indicated that an 8-week RS training program (a) significantly improves acceleration and leg power (CMJ and 5BT) performance but is no more effective than an 8-week NRS training program, (b) significantly improves reactive strength (50DJ), and (c) has minimal impact on gait and upper- and lower-body kinematics during acceleration performance compared to an 8-week NRS training program. These findings suggest that RS training will not adversely affect acceleration kinematics and gait. Although apparently no more effective than NRS training, this training modality provides an overload stimulus to acceleration mechanics and recruitment of the hip and knee extensors, resulting in greater application of horizontal power.

  20. Effects of three types of resisted sprint training devices on the kinematics of sprinting at maximum velocity.

    PubMed

    Alcaraz, Pedro E; Palao, José M; Elvira, José L L; Linthorne, Nicholas P

    2008-05-01

    Resisted sprint running is a common training method for improving sprint-specific strength. For maximum specificity of training, the athlete's movement patterns during the training exercise should closely resemble those used when performing the sport. The purpose of this study was to compare the kinematics of sprinting at maximum velocity to the kinematics of sprinting when using three of types of resisted sprint training devices (sled, parachute, and weight belt). Eleven men and 7 women participated in the study. Flying sprints greater than 30 m were recorded by video and digitized with the use of biomechanical analysis software. The test conditions were compared using a 2-way analysis of variance with a post-hoc Tukey test of honestly significant differences. We found that the 3 types of resisted sprint training devices are appropriate devices for training the maximum velocity phase in sprinting. These devices exerted a substantial overload on the athlete, as indicated by reductions in stride length and running velocity, but induced only minor changes in the athlete's running technique. When training with resisted sprint training devices, the coach should use a high resistance so that the athlete experiences a large training stimulus, but not so high that the device induces substantial changes in sprinting technique. We recommend using a video overlay system to visually compare the movement patterns of the athlete in unloaded sprinting to sprinting with the training device. In particular, the coach should look for changes in the athlete's forward lean and changes in the angles of the support leg during the ground contact phase of the stride.

  1. Odd sensation induced by moving-phantom which triggers subconscious motor program.

    PubMed

    Fukui, Takao; Kimura, Toshitaka; Kadota, Koji; Shimojo, Shinsuke; Gomi, Hiroaki

    2009-06-03

    Our motor actions are sometimes not properly performed despite our having complete understanding of the environmental situation with a suitable action intention. In most cases, insufficient skill for motor control can explain the improper performance. A notable exception is the action of stepping onto a stopped escalator, which causes clumsy movements accompanied by an odd sensation. Previous studies have examined short-term sensorimotor adaptations to treadmills and moving sleds, but the relationship between the odd sensation and behavioral properties in a real stopped-escalator situation has never been examined. Understanding this unique action-perception linkage would help us to assess the brain function connecting automatic motor controls and the conscious awareness of action. Here we directly pose a question: Does the odd sensation emerge because of the unfamiliar motor behavior itself toward the irregular step-height of a stopped escalator or as a consequence of an automatic habitual motor program cued by the escalator itself. We compared the properties of motor behavior toward a stopped escalator (SE) with those toward moving escalator and toward a wooden stairs (WS) that mimicked the stopped escalator, and analyzed the subjective feeling of the odd sensation in the SE and WS conditions. The results show that moving escalator-specific motor actions emerged after participants had stepped onto the stopped escalator despite their full awareness that it was stopped, as if the motor behavior was guided by a "phantom" of a moving escalator. Additionally, statistical analysis reveals that postural forward sway that occurred after the stepping action is directly linked with the odd sensation. The results suggest a dissociation between conscious awareness and subconscious motor control: the former makes us perfectly aware of the current environmental situation, but the latter automatically emerges as a result of highly habituated visual input no matter how unsuitable

  2. Development of a Ground-Based Analog to the Advanced Resistive Exercise Device Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Newby, Nathaniel J.; Scott-Pandorf, M. M.; Caldwell, E.; DeWitt, J.K.; Fincke, R.; Peters, B.T.

    2010-01-01

    NASA and Wyle engineers constructed a Horizontal Exercise Fixture (HEF) that was patented in 2006. Recently modifications were made to HEF with the goal of creating a device that mimics squat exercise on the Advanced Resistive Exercise Device (ARED) and can be used by bed rest subjects who must remain supine during exercise. This project posed several engineering challenges, such as how best to reproduce the hip motions (we used a sled that allowed hip motion in the sagittal plane), how to counterweight the pelvis against gravity (we used a pulley and free-weight mechanism), and how to apply large loads (body weight plus squat load) to the shoulders while simultaneously supporting the back against gravity (we tested a standard and a safety bar that allowed movement in the subject s z-axis, both of which used a retractable plate for back support). METHODS An evaluation of the HEF was conducted with human subjects (3F, 3M), who performed sets of squat exercises of increasing load from 10-repetition maximum (RM) up to 1-RM. Three pelvic counterweight loads were tested along with each of the two back-support squat bars. Data collection included 3-dimensional ground reaction forces (GRF), muscle activation (EMG), body motion (video-based motion capture), and subjective comments. These data were compared with previous ground-based ARED study data. RESULTS All subjects in the evaluation were able to perform low- to high-loading squats on the HEF. Four of the 6 subjects preferred a pelvic counterweight equivalent to 60 percent of their body weight. Four subjects preferred the standard squat bar, whereas 2 female subjects preferred the safety bar. EMG data showed muscle activation in the legs and low back typical of squat motion. GRF trajectories and eccentric-concentric loading ratios were similar to ARED. CONCLUSION: Squat exercise performed on HEF approximated squat exercise on ARED.

  3. Analysis of spinal motion and loads during frontal impacts. Comparison between PMHS and ATD.

    PubMed

    Lopez-Valdes, Francisco J; Lau, Anthony; Lamp, John; Riley, Patrick; Lessley, David J; Damon, Andrew; Kindig, Matthew; Kent, Richard; Balasubramanian, Sriram; Seacrist, Thomas; Maltese, Matthew R; Arbogast, Kristy B; Higuchi, Kazuo; Tanji, Hiro

    2010-01-01

    Quantifying the kinematics of the human spine during a frontal impact is a challenge due to the multi-degree-of-freedom structure of the vertebral column. This papers reports on a series of six frontal impacts sled tests performed on three Post Mortem Human Surrogates (PMHS). Each subject was exposed first to a low-speed, non-injurious frontal impact (9 km/h) and then to a high-speed one (40 km/h). Five additional tests were performed using the Hybrid III 50(th) percentile male ATD for comparison with the PMHS. A 3D motion capture system was used to record the 6-degree-of-freedom motion of body segments (head, T1, T8, L2, L4 and pelvis). The 3D trajectories of individual bony structures in the PMHS were determined using bone-mounted marker arrays, thus avoiding skin-attached markers and their potential measurements artifacts. The PMHS spines showed different behavior between low and high speed. While at low speed the head and upper spinal segments lagged the lower portion of the spine and pelvis in reaching their maximum forward displacement (time for maximum forward head excursion was 254.3±31.9 ms and 140.3±9 ms for the pelvis), these differences were minimal at high speed (127±2.6 ms for the head vs. 116.7±3.5 ms for the pelvis). The ATD did not exhibit this speed-dependant behavior. Furthermore, the ATD's forward displacements were consistently less than those exhibited by the PMHS, regardless of the speed. Neck loads at the atlanto-occipital joint were estimated for the PMHS using inverse dynamics techniques and compared to those measured in the ATD. It was found that the axial and shear forces and the flexion moment at the upper neck of the PMHS were higher than those measured in the ATD.

  4. Predicting Rib Fracture Risk With Whole-Body Finite Element Models: Development and Preliminary Evaluation of a Probabilistic Analytical Framework

    PubMed Central

    Forman, Jason L.; Kent, Richard W.; Mroz, Krystoffer; Pipkorn, Bengt; Bostrom, Ola; Segui-Gomez, Maria

    2012-01-01

    This study sought to develop a strain-based probabilistic method to predict rib fracture risk with whole-body finite element (FE) models, and to describe a method to combine the results with collision exposure information to predict injury risk and potential intervention effectiveness in the field. An age-adjusted ultimate strain distribution was used to estimate local rib fracture probabilities within an FE model. These local probabilities were combined to predict injury risk and severity within the whole ribcage. The ultimate strain distribution was developed from a literature dataset of 133 tests. Frontal collision simulations were performed with the THUMS (Total HUman Model for Safety) model with four levels of delta-V and two restraints: a standard 3-point belt and a progressive 3.5–7 kN force-limited, pretensioned (FL+PT) belt. The results of three simulations (29 km/h standard, 48 km/h standard, and 48 km/h FL+PT) were compared to matched cadaver sled tests. The numbers of fractures predicted for the comparison cases were consistent with those observed experimentally. Combining these results with field exposure informantion (ΔV, NASS-CDS 1992–2002) suggests a 8.9% probability of incurring AIS3+ rib fractures for a 60 year-old restrained by a standard belt in a tow-away frontal collision with this restraint, vehicle, and occupant configuration, compared to 4.6% for the FL+PT belt. This is the first study to describe a probabilistic framework to predict rib fracture risk based on strains observed in human-body FE models. Using this analytical framework, future efforts may incorporate additional subject or collision factors for multi-variable probabilistic injury prediction. PMID:23169122

  5. Deflections from two types of human surrogates in oblique side impacts.

    PubMed

    Yoganandan, Narayan; Pintar, Frank A

    2008-10-01

    The objective of the study was to obtain time-dependent thoracic and abdominal deflections of an anthropomorphic test device, the WorldSID dummy, in oblique impact using sled tests, and compare with post mortem human subject (PMHS) data. To simulate the oblique loading vector, the load wall was configured such that the thorax and abdominal plates were offset by twenty or thirty degrees. Deflections were obtained from a chestband placed at the middle thoracic level and five internal deflection transducers. Data were compared from the chestband and the transducer located at the same level of the thorax. In addition, data were compared with deflections from similar PMHS tests obtained using chestbands placed at the level of the axilla, xyphoid process, and tenth rib, representing the upper thorax, middle thorax, and abdominal region of the biological specimen. Peak deflections ranged from 30 to 85 mm in the dummy tests. Peak deflections ranged from 60 to 115 mm in PMHS. Under both obliquities, dummy deflection-time histories at the location along the chestband in close proximity to the internal deflection transducer demonstrated similar profiles. However, the peak deflection magnitudes from the chestband were approximately 20 mm greater than those from the internal transducer. Acknowledging that the chestband measures external deflections in contrast to the transducer which records internal ribcage deformations, peak deflections match from the two sensors. Deflection time histories were also similar between the dummy and PMHS in terms of morphology, although thoracic deflection magnitudes from the dummy matched more closely with PMHS than abdominal deflection magnitudes. The dummy deformed in such a way that peak deflections occurred along the lateral vector. This was in contrast to PMHS tests wherein maximum deflections occurred along the antero-lateral direction, suggesting differing deformation responses in the two models. In addition, peak deflections occurred

  6. Simultaneous Three-Dimensional Analysis of Cervical Spine Kinematics in the Axial and Sagittal Views during a Simulated Frontal Impact: Differences between Tensed and Relaxed States

    PubMed Central

    Sakane, Masataka; Ejima, Susumu; Ito, Daisuke; Nishino, Tomofumi; Kitajima, Sou; Yamazaki, Masashi

    2015-01-01

    Study Design Prospective experimental study on humans. Purpose To determine whether postural differences during a low-speed impact are observed in the sagittal and axial views, particularly in a relaxed state. Overview of Literature: Three-dimensional motion capture systems have been used to analyze posture and head-neck-torso kinematics in humans during a simulated low-speed impact, yet little research has focused on the axial view. Since a seatbelt asymmetrically stabilizes a drivers right shoulder and left lower waist into the seat, it potentially creates movement in the axial view. Methods Three healthy adult men participated in the experimental series, which used a low-speed sled system. The acceleration pulse created a full sine shape with a maximum acceleration of 8.0 m/s2 at 500 ms, during which the kinematics were evaluated in relaxed and tensed states. The three-dimensional motion capture system used eight markers to record and analyze body movement and head-neck-torso kinematics in the sagittal and axial views during the low-speed impact. Head and trunk rotation angles were also calculated. Results Larger movements were observed in the relaxed than in the tensed state in the sagittal view. The cervical and thoracic spine flexed and extended, respectively, in the relaxed state. In the axial view, larger movements were also observed in the relaxed state than in the tensed state, and the left shoulder rotated. Conclusions During simulated frontal impact, the rotation angle between the head and trunk was significantly larger in the relaxed state. Therefore, we recommend also observing movement in the axial view during impact tests. PMID:26713119

  7. Evaluation of the internal and external biofidelity of current rear impact ATDs to response targets developed from moderate-speed rear impacts of PMHS.

    PubMed

    Moorhouse, Kevin; Donnelly, Bruce; Kang, Yun-Seok; Bolte, John H; Herriott, Rodney

    2012-10-01

    The goal of this study is to evaluate both the internal and external biofidelity of existing rear impact anthropomorphic test devices (BioRID II, RID3D, Hybrid III 50th) in two moderate-speed rear impact sled test conditions (8.5g, 17 km/h; 10.5g, 24 km/h) by quantitatively comparing the ATD responses to biomechanical response targets developed from PMHS testing in a corresponding study. The ATDs and PMHS were tested in an experimental seat system that is capable of simulating the dynamic seat back rotation response of production seats. The experimental seat contains a total of fourteen load cells installed such that external loads from the ATDs and PMHS can be measured to evaluate external biofidelity. The PMHS were instrumented to correspond to the instrumentation contained in the ATDs so that direct comparison between ATDs and PMHS could be made to evaluate internal biofidelity. The NHTSA Biofidelity Ranking system was used to quantitatively evaluate the biofidelity of the ATDs and an additional tool was introduced and utilized which allows for the biofidelity score to be partitioned into components of amplitude, phase, and shape. For internal biofidelity, the BioRID II and RID3D were more biofidelic than the Hybrid III in the 17 km/h test, and the BioRID II was most biofidelic in the 24 km/h test. For external biofidelity, the BioRID II was most biofidelic in the 17 km/h test, while both the BioRID II and the RID3D were more biofidelic than the Hybrid III in the 24 km/h test. Overall, the BioRID II demonstrated the best biofidelity in both the 17 km/h and 24 km/h tests.

  8. Response and Tolerance of Female and/or Elderly PMHS to Lateral Impact.

    PubMed

    Wood, Lauren K; Miller, Carl S; Madura, Nathaniel H; Reed, Matthew P; Schneider, Lawrence W; Klinich, Kathleen D; Rupp, Jonathan D

    2014-11-01

    Eight whole fresh-frozen cadavers (6 female, 2 male) that were elderly and/or female were laterally impacted using UMTRI's dual-sled side-impact test facility. Cadavers were not excluded on the basis of old age or bone diseases that affect tolerance. A thinly padded, multi-segment impactor was used that independently measured force histories applied to the shoulder, thorax, abdomen, greater trochanter, iliac wing, and femur of each PMHS. Impactor plates were adjusted vertically and laterally toward the subject so that contact with body regions occurred simultaneously and so that each segment contacted the same region on every subject. This configuration minimized the effects of body shape on load sharing between regions. Prior to all tests, cadavers were CT scanned to check for pre-existing skeletal injuries. Cadavers were excluded if they had preexisting rib fractures or had undergone CPR. Cadavers were instrumented with strain gages at the posterolateral, lateral, and anterolateral portions of the struck-side ribs, and chestbands were positioned on the upper and lower thorax. Cadavers were first impacted at 3 m/s. If two or fewer rib fractures occurred, as determined using strain gage data and a post-test CT scan, a second impact was performed at 6 m/s on the contralateral side of the body. Five of the eight 3-m/s tests produced AIS 3+ level injuries. All three of the 6-m/s tests produced AIS 3+ injury. Response corridors were developed for each body region using the Maltese alignment method with impulse-momentum normalization. Corridors describing upper and lower thorax deflection were generated from chestband data. An injury risk curve developed from the deflections associated with AIS 3+ injury associates a 50% probability of AIS 3+ rib fracture with 25.6% half-thorax deflection for the population used in this study.

  9. Kinematic Comparison of the Hybrid III and Q-Series Pediatric ATDs to Pediatric Volunteers in Low-Speed Frontal Crashes

    PubMed Central

    Seacrist, Thomas; Mathews, Emily A.; Samuels, Marina; García-España, J. Felipe; Longhitano, Douglas; St. Lawrence, Schuyler; Balasubramanian, Sriram; Maltese, Matthew R.; Arbogast, Kristy B.

    2012-01-01

    Previous research has suggested that the rigid pediatric ATD spine may not adequately represent the relatively mobile, multi-segmented spine of the child and thus may lead to important differences in the head trajectory of the ATD relative to a human. Recently we compared the responses of size-matched child volunteers to the Hybrid III 6-year-old ATD in low-speed frontal sled tests, illustrating differences in head, spinal, and pelvic kinematics as well as seating environment reaction loads. This paper expands this line of work to include comparisons between size-matched restrained child volunteers to the Hybrid III 10-year-old and the Q-series 6 and 10-year-old ATDs tested in the same low speed frontal environment. A 3-D near-infrared video target tracking system quantified the position of markers on the ATDs and volunteers(head top, nasion, external auditory meatus, C4, T1, and pelvis). Angular velocity of the head, seat belt forces, and reaction loads on the seat pan and foot rest were also measured. The Hybrid III 6 and Q6 exhibited significantly greater belt reaction loads compared to the pediatric volunteers, which exhibited greater seat pan shear. Compared to children, the Hybrid III 6 exhibited increased head rotation and similar head top and pelvic excursion, whereas the Q6 exhibited reductions in all three metrics. The Hybrid III 10 and Q10 ATDs exhibited reaction loads similar to the volunteers; however, excursions and head rotation were significantly reduced compared to volunteers. All pediatric ATDs exhibited significant reductions in C4 and T1excursions compared to the volunteers, likely due to the rigidity of the ATD thoracic spine. These analyses provide insight into aspects of ATD biofidelity in low-speed crash environments and illustrate differences in responses of the Hybrid III and Q-series pediatric ATDs. PMID:23169138

  10. Simulated combined abnormal environment fire calculations for aviation impacts.

    SciTech Connect

    Brown, Alexander L.

    2010-08-01

    Aircraft impacts at flight speeds are relevant environments for aircraft safety studies. This type of environment pertains to normal environments such as wildlife impacts and rough landings, but also the abnormal environment that has more recently been evidenced in cases such as the Pentagon and World Trade Center events of September 11, 2001, and the FBI building impact in Austin. For more severe impacts, the environment is combined because it involves not just the structural mechanics, but also the release of the fuel and the subsequent fire. Impacts normally last on the order of milliseconds to seconds, whereas the fire dynamics may last for minutes to hours, or longer. This presents a serious challenge for physical models that employ discrete time stepping to model the dynamics with accuracy. Another challenge is that the capabilities to model the fire and structural impact are seldom found in a common simulation tool. Sandia National Labs maintains two codes under a common architecture that have been used to model the dynamics of aircraft impact and fire scenarios. Only recently have these codes been coupled directly to provide a fire prediction that is better informed on the basis of a detailed structural calculation. To enable this technology, several facilitating models are necessary, as is a methodology for determining and executing the transfer of information from the structural code to the fire code. A methodology has been developed and implemented. Previous test programs at the Sandia National Labs sled track provide unique data for the dynamic response of an aluminum tank of liquid water impacting a barricade at flight speeds. These data are used to validate the modeling effort, and suggest reasonable accuracy for the dispersion of a non-combustible fluid in an impact environment. The capability is also demonstrated with a notional impact of a fuel-filled container at flight speed. Both of these scenarios are used to evaluate numeric approximations

  11. Validation of the 5th and 95th Percentile Hybrid III Anthropomorphic Test Device Finite Element Model

    NASA Technical Reports Server (NTRS)

    Lawrence, C.; Somers, J. T.; Baldwin, M. A.; Wells, J. A.; Newby, N.; Currie, N. J.

    2014-01-01

    NASA spacecraft design requirements for occupant protection are a combination of the Brinkley criteria and injury metrics extracted from anthropomorphic test devices (ATD's). For the ATD injury metrics, the requirements specify the use of the 5th percentile female Hybrid III and the 95th percentile male Hybrid III. Furthermore, each of these ATD's is required to be fitted with an articulating pelvis and a straight spine. The articulating pelvis is necessary for the ATD to fit into spacecraft seats, while the straight spine is required as injury metrics for vertical accelerations are better defined for this configuration. The requirements require that physical testing be performed with both ATD's to demonstrate compliance. Before compliance testing can be conducted, extensive modeling and simulation are required to determine appropriate test conditions, simulate conditions not feasible for testing, and assess design features to better ensure compliance testing is successful. While finite element (FE) models are currently available for many of the physical ATD's, currently there are no complete models for either the 5th percentile female or the 95th percentile male Hybrid III with a straight spine and articulating pelvis. The purpose of this work is to assess the accuracy of the existing Livermore Software Technology Corporation's FE models of the 5th and 95th percentile ATD's. To perform this assessment, a series of tests will be performed at Wright Patterson Air Force Research Lab using their horizontal impact accelerator sled test facility. The ATD's will be placed in the Orion seat with a modified-advanced-crew-escape-system (MACES) pressure suit and helmet, and driven with loadings similar to what is expected for the actual Orion vehicle during landing, launch abort, and chute deployment. Test data will be compared to analytical predictions and modelling uncertainty factors will be determined for each injury metric. Additionally, the test data will be used to

  12. Strong depth-related zonation of megabenthos on a rocky continental margin (∼700-4000 m) off southern Tasmania, Australia.

    PubMed

    Thresher, Ronald; Althaus, Franziska; Adkins, Jess; Gowlett-Holmes, Karen; Alderslade, Phil; Dowdney, Jo; Cho, Walter; Gagnon, Alex; Staples, David; McEnnulty, Felicity; Williams, Alan

    2014-01-01

    Assemblages of megabenthos are structured in seven depth-related zones between ∼700 and 4000 m on the rocky and topographically complex continental margin south of Tasmania, southeastern Australia. These patterns emerge from analysis of imagery and specimen collections taken from a suite of surveys using photographic and in situ sampling by epibenthic sleds, towed video cameras, an autonomous underwater vehicle and a remotely operated vehicle (ROV). Seamount peaks in shallow zones had relatively low biomass and low diversity assemblages, which may be in part natural and in part due to effects of bottom trawl fishing. Species richness was highest at intermediate depths (1000-1300 m) as a result of an extensive coral reef community based on the bioherm-forming scleractinian Solenosmilia variabilis. However, megabenthos abundance peaked in a deeper, low diversity assemblage at 2000-2500 m. The S. variabilis reef and the deep biomass zone were separated by an extensive dead, sub-fossil S. variabilis reef and a relatively low biomass stratum on volcanic rock roughly coincident with the oxygen minimum layer. Below 2400 m, megabenthos was increasingly sparse, though punctuated by occasional small pockets of relatively high diversity and biomass. Nonetheless, megabenthic organisms were observed in the vast majority of photographs on all seabed habitats and to the maximum depths observed--a sandy plain below 3950 m. Taxonomic studies in progress suggest that the observed depth zonation is based in part on changing species mixes with depth, but also an underlying commonality to much of the seamount and rocky substrate biota across all depths. Although the mechanisms supporting the extraordinarily high biomass in 2000-2500 m depths remains obscure, plausible explanations include equatorwards lateral transport of polar production and/or a response to depth-stratified oxygen availability.

  13. Deflection measurement system for the hybrid iii six-year-old biofidelic abdomen.

    PubMed

    Gregory, T Stan; Howes, Meghan K; Rouhana, Stephen W; Hardy, Warren N

    2012-01-01

    Motor vehicle collisions are the leading cause of death for children ages 5 to 14. Enhancement of child occupant protection is partly dependent on the ability to accurately assess the interaction of child-size occupants with restraint systems. Booster seat design and belt fit are evaluated using child anthropomorphic test devices, such as the Hybrid III 6-year-old dummy., A biofidelic abdomen for the Hybrid III 6-year-old dummy is being developed by the Ford Motor Company to enhance the dummy’s ability to assess injury risk and further quantify submarining risk by measuring abdominal deflection. A practical measurement system for the biofidelic abdominal insert has been developed and demonstrated for three dimensional determination of abdominal deflection. Quantification of insert deflection is achieved via differential signal measurement using electrodes mounted within a conductive medium. Signal amplitude is proportional to the distance between the electrodes. A microcontroller is used to calculate distances between ventral electrodes and a dorsal electrode in three dimensions. This system has been calibrated statically, and its performance demonstrated in a series of sled tests. Deflection measurements from the instrumented abdominal insert indicate performance differences between two booster seat designs, yielding an average peak anterior to posterior displacement of the abdomen of 1.0 ± 3.4 mm and 31.2 ± 7.2 mm for the seats, respectively. Implementation of a 6-year-old abdominal insert with the ability to evaluate submarining potential will likely help safety researchers further enhance booster seat design and interaction with vehicle restraint systems , and help to further understand child occupant injury risk in automobile collisions.

  14. Analysis of towed camera images to determine the effects of disposed mustard-filled bombs on the deep water benthic community off south Oahu

    NASA Astrophysics Data System (ADS)

    Kelley, Christopher; Carton, Geoffrey; Tomlinson, Michael; Gleason, Arthur

    2016-06-01

    Still images from a towed camera sled were used to evaluate the potential ecological effects of M47A2 mustard-filled (1,1‧-thiobis[2-chloroethane]) bombs disposed of in over 500 m of water off the south coast of Oahu in 1944. The types of munitions and munitions debris in the images were identified by an ordnance and explosives safety specialist. To the extent feasible, non-munitions related debris were also identified. Biologists then examined the images and identified the types and numbers of animals: (1) on or near (<1 m) the M47A2 bombs; (2) on other manmade debris, including other munitions; and (3) on the natural substrate that was predominantly sediment with little, if any, topographic relief. Multivariate statistical techniques were used to analyze these data to identify differences between the biota inhabiting the three substrates. The analysis indicated that the types and numbers of animals associated with the M47A2 bombs were not significantly different from those observed on other types of munitions and other manmade debris; however they were significantly different from the animals found only on the natural sediment. Based on these results, it appears that the mustard-filled bombs are providing hard substrate similar to other disposed objects, attracting "hard substrate species" that would not have otherwise colonized the area. Even though it is apparent that many of the mustard-filled bombs have breached and their contents exposed, the analysis did not find any evidence of animals avoiding the mustard-filled bombs.

  15. Aqueous glucose measurement using differential absorption-based frequency domain optical coherence tomography at wavelengths of 1310 nm and 1625 nm

    NASA Astrophysics Data System (ADS)

    John, Pauline; Manoj, Murali; Sujatha, N.; Vasa, Nilesh J.; Rao, Suresh R.

    2015-07-01

    This work presents a combination of differential absorption technique and frequency domain optical coherence tomography for detection of glucose, which is an important analyte in medical diagnosis of diabetes. Differential absorption technique is used to detect glucose selectively in the presence of interfering species especially water and frequency domain optical coherence tomography (FDOCT) helps to obtain faster acquisition of depth information. Two broadband super-luminescent diode (SLED) sources with centre wavelengths 1586 nm (wavelength range of 1540 to 1640 nm) and 1312 nm (wavelength range of 1240 to 1380 nm) and a spectral width of ≍ 60 nm (FWHM) are used. Preliminary studies on absorption spectroscopy using various concentrations of aqueous glucose solution gave promising results to distinguish the absorption characteristics of glucose at two wavelengths 1310 nm (outside the absorption band of glucose) and 1625 nm (within the absorption band of glucose). In order to mimic the optical properties of biological skin tissue, 2% and 10% of 20% intralipid with various concentrations of glucose (0 to 4000 mg/dL) was prepared and used as sample. Using OCT technique, interference spectra were obtained using an optical spectrum analyzer with a resolution of 0.5 nm. Further processing of the interference spectra provided information on reflections from the surfaces of the cuvette containing the aqueous glucose sample. Due to the absorption of glucose in the wavelength range of 1540 nm to 1640 nm, a trend of reduction in the intensity of the back reflected light was observed with increase in the concentration of glucose.

  16. High energy particles at Mars and Venus: Phobos-2, Mars Express and Venus Express observations and their interpretation by hybrid model simulations

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, Susan; Kallio, Esa; Fram, Rudy A.; Alho, Markku; Jarvinen, Riku; Dyadechkin, Sergey; Wedlund, Cyril Simon; Zhang, Tielong; Collinson, Glyn A.; Futaana, Yoshifumi

    2013-04-01

    Mars and Venus can both be reached by Solar Energetic Particles (SEPs). Such high energy particles (protons, multiply charged heavy ions, electrons) penetrate the upper atmospheres of Mars and Venus because, in contrast to Earth, these bodies do not have a significant, global, intrinsic magnetic field to exclude them. One especially well documented, complex and prolonged SEP took in place in early 1989 (Solar Cycle 23) when the Phobos-2 spacecraft was orbiting Mars. This spacecraft had a dedicated high energy particle instrument onboard (SLED), which measured particles with energies in the keV range up to a few tens of MeV. There was in addition a magnetometer as well as solar wind plasma detectors onboard which together provided complementary data to support contemporaneous studies of the background SEP environment. Currently, while the Sun is displaying maximum activity (Solar Cycle 24), Mars and Venus are being individually monitored by instrumentation flown onboard the Mars Express (MEX) and Venus Express (VEX) spacecraft. Neither of these spacecraft carry a high energy particle instrument but their Analyzer of Space Plasmas and Energetic Atoms (ASPERA) experiments (ASPERA-3 on MEX and ASPERA-4 on VEX), can be used to study SEPs integrated over E ≥ ~30 MeV which penetrate the instrument hardware and form background counts in the plasma data. In the present work we present SEP events measured at Mars and Venus based on Phobos-2, 1989 data and on, more recent, MEX and VEX (identified from particle background) observations. We further introduce numerical global SEP simulations of the measured events based on 3-D self-consistent hybrid models (HYB-Mars and HYB-Venus). Through comparing the in situ SEP observations with these simulations, new insights are provided into the properties of the measured SEPs as well as into how their individual planetary bow shocks and magnetospheres affect the characteristics of their ambient Martian and Venusian SEP environments.

  17. Improvement of brain segmentation accuracy by optimizing non-uniformity correction using N3.

    PubMed

    Zheng, Weili; Chee, Michael W L; Zagorodnov, Vitali

    2009-10-15

    Smoothly varying and multiplicative intensity variations within MR images that are artifactual, can reduce the accuracy of automated brain segmentation. Fortunately, these can be corrected. Among existing correction approaches, the nonparametric non-uniformity intensity normalization method N3 (Sled, J.G., Zijdenbos, A.P., Evans, A.C., 1998. Nonparametric method for automatic correction of intensity nonuniformity in MRI data. IEEE Trans. Med. Imag. 17, 87-97.) is one of the most frequently used. However, at least one recent study (Boyes, R.G., Gunter, J.L., Frost, C., Janke, A.L., Yeatman, T., Hill, D.L.G., Bernstein, M.A., Thompson, P.M., Weiner, M.W., Schuff, N., Alexander, G.E., Killiany, R.J., DeCarli, C., Jack, C.R., Fox, N.C., 2008. Intensity non-uniformity correction using N3 on 3-T scanners with multichannel phased array coils. NeuroImage 39, 1752-1762.) suggests that its performance on 3 T scanners with multichannel phased-array receiver coils can be improved by optimizing a parameter that controls the smoothness of the estimated bias field. The present study not only confirms this finding, but additionally demonstrates the benefit of reducing the relevant parameter values to 30-50 mm (default value is 200 mm), on white matter surface estimation as well as the measurement of cortical and subcortical structures using FreeSurfer (Martinos Imaging Centre, Boston, MA). This finding can help enhance precision in studies where estimation of cerebral cortex thickness is critical for making inferences.

  18. Resisted sprints do not acutely enhance sprinting performance.

    PubMed

    Whelan, Niamh; OʼRegan, Ciaran; Harrison, Andrew J

    2014-07-01

    Sprinting speed is a vital component of successful performance in many sports. Long-term resisted sprint training has been shown to improve early acceleration performance, but the acute post-activation potentiation (PAP) effects of resisted sprinting on subsequent performance remain unclear. The purpose of this investigation was to examine the effects of resisted sprinting on sprinting and factors related to sprint performance. Twelve active males participated in a pretest involving ten 10-m sprints through dual-beam timing gates and 10-m Optojump Next System with full recovery. This provided baseline data on step rate, step length, ground contact time, and running speed over the first 6 steps of a maximum effort sprint. One week later, the participants performed three 10-m resisted sprints using a sled loaded to 25-30% body mass followed by a 10-m sprint at 1, 2, 4, 6, 8, and 10 minutes after the final resisted sprint. The data were analyzed using an adapted typical error analysis and repeated measures analysis of variance. The results using analysis of variance provided evidence of significant initial fatigue followed by the enhancement of mean step rate, contact time, reactive strength index, and running speed in 10-m sprints performed after the resisted sprinting (p > 0.05). By contrast, the typical error analysis showed that this enhancement was limited and unsystematic in nature with little clear evidence of fatigue followed by potentiation. The results using typical error data do not provide strong evidence of PAP in 10-m sprint performance after resisted sprinting.

  19. Survey report of NOAA Ship McArthur II cruises AR-04-04, AR-05-05 and AR-06-03: habitat classification of side scan sonar imagery in support of deep-sea coral/sponge explorations at the Olympic Coast National Marine Sanctuary

    USGS Publications Warehouse

    Intelmann, Steven S.; Cochrane, Guy R.; Bowlby, C. Edward; Brancato, Mary Sue; Hyland, Jeffrey

    2007-01-01

    Habitat mapping and characterization has been defined as a high-priority management issue for the Olympic Coast National Marine Sanctuary (OCNMS), especially for poorly known deep-sea habitats that may be sensitive to anthropogenic disturbance. As a result, a team of scientists from OCNMS, National Centers for Coastal Ocean Science (NCCOS), and other partnering institutions initiated a series of surveys to assess the distribution of deep-sea coral/sponge assemblages within the sanctuary and to look for evidence of potential anthropogenic impacts in these critical habitats. Initial results indicated that remotely delineating areas of hard bottom substrate through acoustic sensing could be a useful tool to increase the efficiency and success of subsequent ROV-based surveys of the associated deep-sea fauna. Accordingly, side scan sonar surveys were conducted in May 2004, June 2005, and April 2006 aboard the NOAA Ship McArthur II to: (1) obtain additional imagery of the seafloor for broader habitat-mapping coverage of sanctuary waters, and (2) help delineate suitable deep-sea coral-sponge habitat, in areas of both high and low commercial-fishing activities, to serve as sites for surveying-in more detail using an ROV on subsequent cruises, Several regions of the sea floor throughout the OCNMS were surveyed and mosaicked at 1-meter pixel resolution. Imagery from the side scan sonar mapping efforts was integrated with other complementary data from a towed camera sled, ROVs, sedentary samples, and bathymetry records to describe geological and biological (where possible) aspects of habitat. Using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999), we created a preliminary map of various habitat polygon features for use in a geographical information system (GIS). This report provides a description of the mapping and groundtruthing efforts as well as results of the image classification procedure for each of the areas surveyed.

  20. The INAF/IAPS Plasma Chamber for ionospheric simulation experiment

    NASA Astrophysics Data System (ADS)

    Diego, Piero

    2016-04-01

    The plasma chamber is particularly suitable to perform studies for the following applications: - plasma compatibility and functional tests on payloads envisioned to operate in the ionosphere (e.g. sensors onboard satellites, exposed to the external plasma environment); - calibration/testing of plasma diagnostic sensors; - characterization and compatibility tests on components for space applications (e.g. optical elements, harness, satellite paints, photo-voltaic cells, etc.); - experiments on satellite charging in a space plasma environment; - tests on active experiments which use ion, electron or plasma sources (ion thrusters, hollow cathodes, field effect emitters, plasma contactors, etc.); - possible studies relevant to fundamental space plasma physics. The facility consists of a large volume vacuum tank (a cylinder of length 4.5 m and diameter 1.7 m) equipped with a Kaufman type plasma source, operating with Argon gas, capable to generate a plasma beam with parameters (i.e. density and electron temperature) close to the values encountered in the ionosphere at F layer altitudes. The plasma beam (A+ ions and electrons) is accelerated into the chamber at a velocity that reproduces the relative motion between an orbiting satellite and the ionosphere (≈ 8 km/s). This feature, in particular, allows laboratory simulations of the actual compression and depletion phenomena which take place in the ram and wake regions around satellites moving through the ionosphere. The reproduced plasma environment is monitored using Langmuir Probes (LP) and Retarding Potential Analyzers (RPA). These sensors can be automatically moved within the experimental space using a sled mechanism. Such a feature allows the acquisition of the plasma parameters all around the space payload installed into the chamber for testing. The facility is currently in use to test the payloads of CSES satellite (Chinese Seismic Electromagnetic Satellite) devoted to plasma parameters and electric field

  1. Biomechanical analysis of motor vehicle seat belt buckles.

    PubMed

    Sances, Anthony; Kumaresan, Srirangam; Clarke, Richard; Renfroe, David; Herbst, Brian; Pozzi, Mark

    2003-01-01

    Various studies have reported that inertially sensitive buckles are susceptible to impact unlatching. The present work synthesizes the results from various experimental studies conducted over the years to study the mechanical behavior of buckles and subsequent injuries to occupants. First, the side press button seat buckle due to impact a lateral impact from an adjacent child restraint seat component indicated that the side button RCF-67 buckle released at a speed of 2.2 m/sec with a force range of 264 to 440 N and acceleration range of 100 to 175 G. In contrast, the top button Autoliv Lockarm buckles did not release up to 1300 vertical G's. Second, side release RCF-67 buckles when loaded with the webbing required approximately three times more force to open than top press buckles. Inverted occupants in a three-point belt could not release the RCF-67 buckle. Third, a side sled impact on the drivers side of a production vehicle buck with a three-point belt and a RCF-67 buckle was done at 7 m/s to 8 m/s. A convertible child seat with a dummy in the passenger seat moved inboard toward the buckle and unlatched it. Fourth, an intact vehicle drop study at 0.3 m showed that the accelerations on a JDC buckle on a metal stalk are large compared to acceleration of the floor pan. The present study provides comprehensive data to evaluate the mechanical behavior of seat buckles under various motor vehicle crash conditions.

  2. Intrusion dynamics of particle plumes in stratified water with weak crossflow: Application to deep ocean blowouts

    NASA Astrophysics Data System (ADS)

    Wang, Dayang; Adams, E. Eric

    2016-06-01

    We present an experimental study of particle plumes in ambient stratification and a mild current. In an inverted framework, the results describe the fate of oil droplets released from a deep ocean blowout. A continuous stream of dense glass beads was released from a carriage towed in a salt-stratified tank. Nondimensional particle slip velocity UN ranged from 0.1 to 1.9, and particles with UN ≤ 0.5 were observed to enter the intrusion layer. The spatial distributions of beads, collected on a bottom sled towed with the source, present a Gaussian distribution in the transverse direction and a skewed distribution in the along-current direction. Dimensions of the distributions increase with decreasing UN. The spreading relations can be used as input to far-field models describing subsequent transport of particles or, in an inverted framework, oil droplets. The average particle settling velocity, Uave, was found to exceed the individual particle slip velocity, Us, which is attributed to the initial plume velocity near the point of release. Additionally, smaller particles exhibit a "group" or "secondary plume" effect as they exit the intrusion as a swarm. The secondary effect becomes more prominent as UN decreases, and might help explain observations from the 2000 Deep Spill field experiment where oil was found to surface more rapidly than predicted based on Us. An analytical model predicting the particle deposition patterns was validated against experimental measurements, and used to estimate near-field oil transport under the Deepwater Horizon spill conditions, with/without chemical dispersants.

  3. Importance of physical and hydraulic characteristics to unionid mussels: A retrospective analysis in a reach of large river

    USGS Publications Warehouse

    Zigler, S.J.; Newton, T.J.; Steuer, J.J.; Bartsch, M.R.; Sauer, J.S.

    2008-01-01

    Interest in understanding physical and hydraulic factors that might drive distribution and abundance of freshwater mussels has been increasing due to their decline throughout North America. We assessed whether the spatial distribution of unionid mussels could be predicted from physical and hydraulic variables in a reach of the Upper Mississippi River. Classification and regression tree (CART) models were constructed using mussel data compiled from various sources and explanatory variables derived from GIS coverages. Prediction success of CART models for presence-absence of mussels ranged from 71 to 76% across three gears (brail, sled-dredge, and dive-quadrat) and 51% of the deviance in abundance. Models were largely driven by shear stress and substrate stability variables, but interactions with simple physical variables, especially slope, were also important. Geospatial models, which were based on tree model results, predicted few mussels in poorly connected backwater areas (e.g., floodplain lakes) and the navigation channel, whereas main channel border areas with high geomorphic complexity (e.g., river bends, islands, side channel entrances) and small side channels were typically favorable to mussels. Moreover, bootstrap aggregation of discharge-specific regression tree models of dive-quadrat data indicated that variables measured at low discharge were about 25% more predictive (PMSE = 14.8) than variables measured at median discharge (PMSE = 20.4) with high discharge (PMSE = 17.1) variables intermediate. This result suggests that episodic events such as droughts and floods were important in structuring mussel distributions. Although the substantial mussel and ancillary data in our study reach is unusual, our approach to develop exploratory statistical and geospatial models should be useful even when data are more limited. ?? 2007 Springer Science+Business Media B.V.

  4. Headless submarine canyons and fluid flow on the toe of the Cascadia accretionary complex

    USGS Publications Warehouse

    Orange, D.L.; McAdoo, B.G.; Moore, J.C.; Tobin, H.; Screaton, E.; Chezar, H.; Lee, H.; Reid, M.; Vail, R.

    1997-01-01

    Headless submarine canyons with steep headwalls and shallowly sloping floors occur on both the second and third landward vergent anticlines on the toe of the Cascadia accretionary complex off central Oregon (45 ??N, 125?? 30??W). In September 1993, we carried out a series of nine deep tow camera sled runs and nine ALVIN dives to examine the relationship between fluid venting, structure and canyon formation. We studied four canyons on the second and third landward vergent anticlines, as well as the apparently unfailed intercanyon regions along strike. All evidence of fluid expulsion is associated with the canyons; we found no evidence of fluid flow between canyons. Even though all fluid seeps are related to canyons, we did not find seeps in all canyons, and the location of the seeps within the canyons differed. On the landward facing limb of the second landward vergent anticline a robust cold seep community occurs at the canyon's inflection point. This seep is characterized by chemosynthetic vent clams, tube worms and extensive authigenic carbonate. Fluids for this seep may utilize high-permeability flow paths either parallel to bedding within the second thrust ridge or along the underlying thrust fault before leaking into the overriding section. Two seaward facing canyons on the third anticlinal ridge have vent clam communities near the canyon mouths at approximately the intersection between the anticlinal ridge and the adjacent forearc basin. No seeps were found along strike at the intersection of the slope basin and anticlinal ridge. We infer that the lack of seepage along strike and the presence of seeps in canyons may be related to fluid flow below the forearc basin/slope unconformity (overpressured by the impinging thrust fault to the west?) directed toward canyons at the surface.

  5. Flatfish-habitat associations in Alaska nursery grounds: Use of continuous video records for multi-scale spatial analysis

    NASA Astrophysics Data System (ADS)

    Stoner, Allan W.; Spencer, Mara L.; Ryer, Clifford H.

    2007-02-01

    Flatfish distributions have traditionally been described in terms of depth, temperature, and sediment characteristics, but other environmental variables may be important depending upon spatial scale. Surveys for age-0 northern rock sole ( Lepidopsetta polyxystra) were conducted in five near-shore nursery sites at Kodiak Island, Alaska, using a towed camera sled integrated with navigational data. The continuous record of fish density and habitat features made possible a spatially comprehensive analysis of fish-habitat associations at several spatial scales, ranging from tens of kilometres to less than 1 m. A combination of multivariate statistical interpretation and geographic information systems (GIS) revealed that the distribution of juvenile rock sole was associated with environmental variables and spatial scales that are not normally detectable with usual flatfish— and habitat—sampling methods (i.e., trawls and grabs). Generalized additive models (GAM) incorporating habitat variables determined from video provided large improvements over models using only the traditional variables such as depth and sediment type. At the broadest (regional) scale of analysis, combinations of sediment composition, surface bedform, temperature, and density of worm tubes provided the best model for rock sole density. Within-nursery variation in fish density was modelled best with depth, habitat structural complexity created by emergent fauna and macroalgae, and worm tube density. At the microhabitat scale (< 1 m), there was little evidence of direct contact between rock sole and structures such as shell or algae. Rather, they were loosely associated on a scale tens of metres. This study showed that spatially comprehensive surveys can be conducted with towed camera systems and without the need for sediment grab samples. This approach yields detailed habitat information for fishes and the opportunity for landscape analysis of spatial patterns that will be important in conserving

  6. Unusual megafaunal assemblages on the continental slope off Cape Hatteras

    NASA Astrophysics Data System (ADS)

    Hecker, Barbara

    Megafaunal assemblages were studied in August-September 1992 using a towed camera sled along seven cross-isobath transects on the continental slope off Cape Hatteras. A total of 20,722 megafaunal organisms were observed on 10,918 m 2 of the sea floor between the depths of 157 and 1 924 m. These data were compared with data previously collected off Cape Hatteras in 1985 and at other locations along the eastern U.S. coast between 1981 and 1987. Megafaunal populations on the upper and lower slopes off Cape Hatteras were fouond to be similar, in terms of density and species composition, to those observed at the other locations. In contrast, megafaunal abundances were found to be elevated (0.88 and 2.65 individuals per m 2 during 1985 and 1992, respectively) on the middle slope off Cape Hatteras when compared to most other slope locations (<0.5individuals per m 2). These elevated abundances mainly reflect dense populations of three demersal fish, two eel pouts ( Lysenchelys verrilli and Lycodes atlanticus) and the witch flounder Glyptocephalus cynoglossus, and a large anemone ( Actinauge verrilli). These four species dominated the megafauna off Cape Hatteras, whereas they represented only a minor component of megafaunal populations found at other slope locations. Additionally, numerous tubes of the foraminiferan Bathysiphon filiformis were observed off Cape Hatteras, but not elsewhere. The high density of demersal fish found off Cape Hatteras appears to be related to the high densities of infaunal prey reported from this area. The high densities of A. verrilli and B. fuliformis may be related to the same factors responsible for the high infaunal densities, namely enhanced nutrient inputs in the form of fine particles. Extreme patchiness also was observed in the distributions of the middle slope taxa off Cape Hatteras. This patchiness may reflect the habitat heterogeneity of this exceptionally rugged slope and the sedentary nature of the organisms inhabiting it.

  7. RF pulse compression for future linear colliders

    SciTech Connect

    Wilson, P.B.

    1995-05-01

    Future (nonsuperconducting) linear colliders will require very high values of peak rf power per meter of accelerating structure. The role of rf pulse compression in producing this power is examined within the context of overall rf system design for three future colliders at energies of 1.0--1.5 TeV, 5 TeV and 25 TeV. In order keep the average AC input power and the length of the accelerator within reasonable limits, a collider in the 1.0--1.5 TeV energy range will probably be built at an x-band rf frequency, and will require a peak power on the order of 150--200 MW per meter of accelerating structure. A 5 TeV collider at 34 GHz with a reasonable length (35 km) and AC input power (225 MW) would require about 550 MW per meter of structure. Two-beam accelerators can achieve peak powers of this order by applying dc pulse compression techniques (induction linac modules) to produce the drive beam. Klystron-driven colliders achieve high peak power by a combination of dc pulse compression (modulators) and rf pulse compression, with about the same overall rf system efficiency (30--40%) as a two-beam collider. A high gain (6.8) three-stage binary pulse compression system with high efficiency (80%) is described, which (compared to a SLED-11 system) can be used to reduce the klystron peak power by about a factor of two, or alternately, to cut the number of klystrons in half for a 1.0--1.5 TeV x-band collider. For a 5 TeV klystron-driven collider, a high gain, high efficiency rf pulse compression system is essential.

  8. Biomechanics of 4-point seat belt systems in farside impacts.

    PubMed

    Rouhana, Stephen W; Kankanala, Sundeep V; Prasad, Priya; Rupp, Jonathan D; Jeffreys, Thomas A; Schneider, Lawrence W

    2006-11-01

    The biomechanical behavior of a harness style 4-point seat belt system in farside impacts was investigated through dummy and post mortem human subject tests. Specifically, this study was conducted to evaluate the effect of the inboard shoulder belt portion of a 4-point seat belt on the risk of vertebral and soft-tissue neck injuries during simulated farside impacts. Two series of sled tests simulating farside impacts were completed with crash dummies of different sizes, masses and designs to determine the forces and moments on the neck associated with loading of the shoulder belt. The tests were also performed to help determine the appropriate dummy to use in further testing. The BioSID and SID-IIs reasonably simulated the expected kinematics response and appeared to be reasonable dummies to use for further testing. Analysis also showed that dummy injury measures were lower than injury assessment reference values used in development of side impact airbags. Six post-mortem human subjects, three small females and three medium sized males, were tested under conditions similar to those used for the dummy tests. The carotid arteries were pressurized in an attempt to simulate the corresponding neck vascular response of living humans. Post-test autopsies conducted on all test subjects indicated an absence of test-induced arterial or vertebral injuries. Further, comparative analysis of kinematics confirmed the adequacy of the BioSID and SID-IIs in simulating cadaveric response in farside impacts with harness style 4-point belts. A number of issues remain to be solved before the implementation of 4-point seat belts in vehicles, including, among others, the risk of injury to a pregnant woman and her fetus in frontal crashes. The risk of fetal injury in pregnant occupants may be related to the location of the 4-point seat belt's buckle and latch junction at the centerline of the mother's abdomen.

  9. Effects of Short- and Long-Duration Space Flight on Neuromuscular Function

    NASA Technical Reports Server (NTRS)

    Buxton, Roxanne E.; Spiering, Barry A.; Ryder, Jeffrey W.; Ploutz-Snyder, Lori L.; Bloomberg, Jacob J.

    2010-01-01

    The Functional Task Tests (FTT) is an interdisciplinary study designed to correlate the changes in functional tasks (such as emergency egress, ladder climbing, and hatch opening) with changes in neuromuscular, cardiovascular, and sensorimotor function. One aspect of the FTT, the neuromuscular function test, is used to investigate the neuromuscular component underlying changes in the ability of astronauts to perform functional tasks (representative of critical mission tasks) safely and quickly after flight. PURPOSE: To describe neuromuscular function after short- and long-duration space flight. METHODS: To date, 5 crewmembers on short-duration (10- to 15-day) missions and 3 on long-duration missions have participated. Crewmembers were assessed 30 days before flight, on landing day (short-duration subjects only) and 1, 6, and 30 days after landing. The interpolated twitch technique, which utilizes a combination of maximal voluntary contractions and electrically evoked contractions, was used to assess the maximal voluntary isometric force (MIF) and central activation capacity of the knee extensors. Leg-press and bench-press devices were used to assess MIF and maximal dynamic power of the lower and upper body respectively. Specifically, power was measured during concentric-only ballistic throws of the leg-press sled and bench-press bar loaded to 40% and 30% of MIF respectively. RESULTS: Data are currently being collected from both Shuttle and ISS crewmembers. Emerging data indicate that measures of knee extensor muscle function are decreased with long-duration flight. DISCUSSION: The relationships between flight duration, neural drive, and muscle performance are of particular interest. Ongoing research will add to the current sample size and will focus on defining changes in muscle performance measures after long-duration space flight.

  10. Probing the Physical Conditions of Dense Molecular Gas in ULIRGs with LVG modelling

    NASA Astrophysics Data System (ADS)

    Leonidaki, Ioanna; Zhang, Zhi-Yu; Greve, Thomas; Xilouris, Manolis

    2015-08-01

    The gas-rich content of Ultra Luminous Infrared Galaxies (ULIRGs) constitutes a great laboratory in characterising the physical processes occuring in molecular gas and hence probing star formation properties. In particular, molecules with large dipole moments such as CS, HCN, HCO+, which are the fuel of star formation, can reveal the physical/excitation conditions of molecular gas phases in galaxies. For that reason, we compiled the aforementioned dense gas tracers in a sample of local (U)LIRGs in order to investigate the physical properties of the gas while at the same time put constrains on their excitation conditions. The sample in use consists of 26 galaxies all observed within the framework of the Herschel Comprehensive (U)LIRG Emission Survey (HerCULES). For all galaxies, we compiled our ground-based spectral line observations as well as all available data from the literature. Using Large Velocity Gradient (LVG) radiative transfer models in these spectral lines and in a wide parameter space [n(H2), Tkin, Nmol], and combining multiple molecules and multiple excitation components, it is possible to break the degeneracy between different parameters and to probe molecular gas physical conditions ranging from the cold and low-density average states in giant molecular clouds all the way up to the state of the gas found only near their star-forming regions. We then analyse the best LVG solution ranges to match the observed SLEDs (using more than one excitation components where necessary) in order to disentangle different molecular gas phases and possibly different molecular gas heating mechanisms.

  11. High-precision beam shaper for coherent and incoherent light using a DLP spatial light modulator

    NASA Astrophysics Data System (ADS)

    Liang, Jinyang; Kohn, Rudolph N., Jr.; Becker, Michael F.; Heinzen, Daniel J.

    2011-03-01

    We designed a precision laser beam shaper using a Texas Instruments digital micromirror device (DMD) with a telescope system containing a pinhole low-pass filter. The performance of the beam shaper was measured by comparing the intensity and wave-front uniformity to the target function and by the energy conversion efficiency. We demonstrated flattop and other laser beam profiles with 1-1.5% root-mean-square (RMS) error for a raw camera image and nearly flat phase. A noise analysis of the system revealed that lower error is possible and that most of the error came from coherent speckle noise in the camera. A previous experiment using a 1064 nm single-mode fiber (SMF) laser produced around 7% beam power conversion efficiency. Here we report improvements in system automation and laser source flexibility that result in increasing both the speed of the system to calculate and produce a beam, and the beam uniformity and energy conversion efficiency. A LabVIEW program was written to accelerate the speed of the iterative process for beam profile refinement. A 760 nm super-luminescent light emitting diode (SLED) and a 781 nm Laser Diode (LD) were used as light sources in order to reduce the beam coherence and approach the ultimate performance of the shaper. Both sources greatly reduced the speckle noise and increased measured intensity uniformity. Experiments achieved less than 0.9% RMS error over the entire flattop area with a diameter of 1.32 mm. In addition, simulations were conducted to determine the optimized wavelengths for different types of DMDs. For the .7XGA DMD, the 5th diffraction order matches 750-800 nm. Matching the laser diode to this wavelength increased the power conversion efficiency (input beam to output beam) to 19.8%.

  12. Laser Tracker III: Sandia National Laboratories` third generation laser tracking system

    SciTech Connect

    Patrick, D.L.

    1995-03-01

    At Sandia Labs` Coyote Canyon Test Complex, it became necessary to develop a precision single station solution to provide time space position information (tspi) when tracking airborne test vehicles. Sandia`s first laser tracker came on line in 1968, replacing the fixed camera technique for producing trajectory data. This system shortened data reduction time from weeks to minutes. Laser Tracker 11 began operations in 1982, replacing the original tracker. It incorporated improved optics and electronics, with the addition of a microprocessor-based real-time control (rtc) system within the main servo loop. The rtc added trajectory prediction with the loss of adequate tracking signal and automatic control of laser beam divergence according to target range. Laser Tracker III, an even more advanced version of the systems, came on line in 1990. Unlike LTII, which is mounted in a trailer and must by moved by a tractor, LTIII is mounted on its own four-wheel drive carrier. This allows the system to be used at even the most remote locations. It also incorporated improved optics and electronics with the addition of absolute ranging, acquisition on the fly, and automatic transition from manual Joystick tracking to laser tracking for aircraft tests. LTIII provides a unique state of the art tracking capability for missile, rocket sled, aircraft, submunition, and parachute testing. Used in conjunction with LTII, the systems together can provide either simultaneous or extended range tracking. Mobility, accuracy, reliability, and cost effectiveness enable these systems to support a variety of testing at Department of Energy and Department of Defense ranges.

  13. Patches of Remnant Frost/Snow on Crater Rim in Northern Summer

    NASA Technical Reports Server (NTRS)

    1999-01-01

    March 1999--it is summer in the martian northern hemisphere, yet patches of frost or snow persist in some areas of the northern plains. Winter ended eight months earlier, in July 1998. Recently, the Mars Orbiter Camera (MOC) passed over a relatively small impact crater located at latitude 68oN (on the Vastitas Borealis plain, north of Utopia Planitia) and took the picture seen at the left, above. The curved crater rims are visible in the upper and lower quarters of the image, and the crater floor is visible at the center right.

    The picture on the right is a magnified view of the crater rim area outlined by a white box in the image on the left. The bright patches are snow or frost left over from the martian winter. These snowfields are so small that a human could walk across one of them in a matter of minutes--or perhaps sled down the small, sloping patch that is seen in a shadowed area near the lower left.

    In winter, the entire scene shown here would be covered by frost. The long strip at the left covers an area 3 km (1.9 mi) wide by 26 km (16 mi) long. The expanded view on the right covers an area 2.9 km (1.8 mi) by 5.3 km (3.3 mi). Illumination is from the upper right.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  14. Bryozoan faunal composition and community structure from the continental shelf off Cap de Creus (Northwestern Mediterranean)

    NASA Astrophysics Data System (ADS)

    Madurell, T.; Zabala, M.; Dominguez-Carrió, C.; Gili, J. M.

    2013-10-01

    Bryozoan specimens obtained in 2009-2010 from the continental shelf off Cap de Creus (Northwestern Mediterranean) were studied. Samples were collected using a Rauschert sled at depths ranging from 61 to 225 m. Bryozoans were present in all 26 samples examined, although they were only abundant in 20 of them. A total of 113 species of Bryozoa were identified (2 Ctenostomata, 90 Cheilostomata and 21 Cyclostomata), most of them are well known to science, although a few of the species have barely or never been cited in the Mediterranean Sea (Hincksinoflustra octodon, Alderina imbellis, Escharella immersa, Neolagenipora collaris and Escharina johnstoni), or are currently poorly described (Lagenipora lepralioides). The species Palmicellaria aff. aviculifera (sensu Gautier, 1957) is redescribed, for which the new name of Palmiskenea gautieri is proposed. Species richness, abundance and biomass were linked to the availability of suitable substrates. Multivariate analysis in relation to environmental data showed that the spatial distribution of the bryozoan species was related to the sediment type. Samples from areas dominated by silt and sandy sediments showed few or no bryozoans, whereas coarse sands and gravels presented higher diversity, abundance and biomass. Within the depth range studied, the faunistic composition of the bryozoan assemblages was similar for the whole continental shelf off Cap de Creus. The bulk of bryozoans was found near the canyon rim. This is related to the proximity of the submarine canyon and its associated hydrological processes. The high diversity and abundance of the bryozoan community located on the circalittoral and shelf-edge off Cap de Creus reflect the presence of critical habitats that are essential for the design of marine protected areas.

  15. Analysis of spinal motion and loads during frontal impacts. Comparison between PMHS and ATD

    PubMed Central

    Lopez-Valdes, Francisco J.; Lau, Anthony; Lamp, John; Riley, Patrick; Lessley, David J.; Damon, Andrew; Kindig, Matthew; Kent, Richard; Balasubramanian, Sriram; Seacrist, Thomas; Maltese, Matthew R.; Arbogast, Kristy B.; Higuchi, Kazuo; Tanji, Hiro

    2010-01-01

    Quantifying the kinematics of the human spine during a frontal impact is a challenge due to the multi-degree-of-freedom structure of the vertebral column. This papers reports on a series of six frontal impacts sled tests performed on three Post Mortem Human Surrogates (PMHS). Each subject was exposed first to a low-speed, non-injurious frontal impact (9 km/h) and then to a high-speed one (40 km/h). Five additional tests were performed using the Hybrid III 50th percentile male ATD for comparison with the PMHS. A 3D motion capture system was used to record the 6-degree-of-freedom motion of body segments (head, T1, T8, L2, L4 and pelvis). The 3D trajectories of individual bony structures in the PMHS were determined using bone-mounted marker arrays, thus avoiding skin-attached markers and their potential measurements artifacts. The PMHS spines showed different behavior between low and high speed. While at low speed the head and upper spinal segments lagged the lower portion of the spine and pelvis in reaching their maximum forward displacement (time for maximum forward head excursion was 254.3±31.9 ms and 140.3±9 ms for the pelvis), these differences were minimal at high speed (127±2.6 ms for the head vs. 116.7±3.5 ms for the pelvis). The ATD did not exhibit this speed-dependant behavior. Furthermore, the ATD’s forward displacements were consistently less than those exhibited by the PMHS, regardless of the speed. Neck loads at the atlanto-occipital joint were estimated for the PMHS using inverse dynamics techniques and compared to those measured in the ATD. It was found that the axial and shear forces and the flexion moment at the upper neck of the PMHS were higher than those measured in the ATD. PMID:21050592

  16. Laser tracker TSPI uncertainty quantification via centrifuge trajectory

    NASA Astrophysics Data System (ADS)

    Romero, Edward; Paez, Thomas; Brown, Timothy; Miller, Timothy

    2009-08-01

    Sandia National Laboratories currently utilizes two laser tracking systems to provide time-space-position-information (TSPI) and high speed digital imaging of test units under flight. These laser trackers have been in operation for decades under the premise of theoretical accuracies based on system design and operator estimates. Advances in optical imaging and atmospheric tracking technology have enabled opportunities to provide more precise six degree of freedom measurements from these trackers. Applying these technologies to the laser trackers requires quantified understanding of their current errors and uncertainty. It was well understood that an assortment of variables contributed to laser tracker uncertainty but the magnitude of these contributions was not quantified and documented. A series of experiments was performed at Sandia National Laboratories large centrifuge complex to quantify TSPI uncertainties of Sandia National Laboratories laser tracker III. The centrifuge was used to provide repeatable and economical test unit trajectories of a test-unit to use for TSPI comparison and uncertainty analysis. On a centrifuge, testunits undergo a known trajectory continuously with a known angular velocity. Each revolution may represent an independent test, which may be repeated many times over for magnitudes of data practical for statistical analysis. Previously these tests were performed at Sandia's rocket sled track facility but were found to be costly with challenges in the measurement ground truth TSPI. The centrifuge along with on-board measurement equipment was used to provide known ground truth position of test units. This paper discusses the experimental design and techniques used to arrive at measures of laser tracker error and uncertainty.

  17. Antenna Measurements: Test & Analysis of the Radiated Emissions from the NASA/Orion Spacecraft - Parachute System Simulator

    NASA Technical Reports Server (NTRS)

    Norgard, John D.

    2012-01-01

    For future NASA Manned Space Exploration of the Moon and Mars, a blunt body capsule, called the Orion Crew Exploration Vehicle (CEV), composed of a Crew Module (CM) and a Service Module (SM), with a parachute decent assembly is planned for reentry back to Earth. A Capsule Parachute Assembly System (CPAS) is being developed for preliminary parachute drop tests at the Yuma Proving Ground (YPG) to simulate high-speed reentry to Earth from beyond Low-Earth-Orbit (LEO) and to provide measurements of landing parameters and parachute loads. The avionics systems on CPAS also provide mission critical firing events to deploy, reef, and release the parachutes in three stages (extraction, drogues, mains) using mortars and pressure cartridge assemblies. In addition, a Mid-Air Delivery System (MDS) is used to separate the capsule from the sled that is used to eject the capsule from the back of the drop plane. Also, high-speed and high-definition cameras in a Video Camera System (VCS) are used to film the drop plane extraction and parachute landing events. To verify Electromagnetic Compatibility (EMC) of the CPAS system from unintentional radiation, Electromagnetic Interference (EMI) measurements are being made inside a semi-anechoic chamber at NASA/JSC at 1m from the electronic components of the CPAS system. In addition, EMI measurements of the integrated CPAS system are being made inside a hanger at YPG. These near-field B-Dot probe measurements on the surface of a parachute simulator (DART) are being extrapolated outward to the 1m standard distance for comparison to the MIL-STD radiated emissions limit.

  18. Advanced design for a seafloor gamma-measurement data-collection system. Final report for the period July 1, 1988-September 30, 1991. Open File Report

    SciTech Connect

    Noakes, J.E.

    1992-08-28

    The Center for Applied Isotope Studies (CAIS) conducted a three-year program to upgrade and field test the Gamma Isotope Measurement System (GIMS), one of several CAIS systems capable of rapid, remote surveillance and collection of seafloor data. The GIMS is designed specifically for detecting the gamma radiation that is emitted by naturally occurring radioactive minerals on or near the seafloor, which can then be used for the interpretation of seafloor lithology. The GIMS consists of a towed sled containing a gamma radiation detector and a battery pack, connected by signal cable to a shipboard data acquisition system. The system processes the gamma spectrum to identify certain radioactive isotopes, simultaneously measuring four levels of radioactivity. Following the three-year system upgrade program, the operational parameters of the GIMS have been substantially improved from the prototype gamma radiation detection systems first developed in the mid-1970s. Gamma radiation detection sensitivity has been increased fourfold with the inclusion of a larger thallium-activated sodium iodide (NaI(Tl)) crystal detector. The maximum operating depth of the system has been doubled to a capability of 300 feet at a towing speed of 3 knots, allowing access to extensive areas of seafloor that were not previously available for rapid survey investigation. Enhanced data processing, storage, and mapping capabilities now provide user access to gamma spectrum analyses and two- and three-dimensional maps in near real time. In addition to these improvements, computer software now in development at CAIS will be applicable to the GIMS system to permit real time mapping within the next year.

  19. Motion Perception and Manual Control Performance During Passive Tilt and Translation Following Space Flight

    NASA Technical Reports Server (NTRS)

    Clement, Gilles; Wood, Scott J.

    2010-01-01

    This joint ESA-NASA study is examining changes in motion perception following Space Shuttle flights and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. METHODS. Data has been collected on 5 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s) combined with body translation (12-22 cm, peak-to-peak) is utilized to elicit roll-tilt perception (equivalent to 20 deg, peak-to-peak). A forward-backward moving sled (24-390 cm, peak-to-peak) with or without chair tilting in pitch is utilized to elicit pitch tilt perception (equivalent to 20 deg, peak-to-peak). These combinations are elicited at 0.15, 0.3, and 0.6 Hz for evaluating the effect of motion frequency on tilt-translation ambiguity. In both devices, a closed-loop nulling task is also performed during pseudorandom motion with and without vibrotactile feedback of tilt. All tests are performed in complete darkness. PRELIMINARY RESULTS. Data collection is currently ongoing. Results to date suggest there is a trend for translation motion perception to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. DISCUSSION. The results of this study indicate that post-flight recovery of motion perception and manual control performance is complete within 8 days following short-duration space missions. Vibrotactile feedback of tilt improves manual control performance both before and after flight.

  20. HyBIS - a low cost, multi-purpose, modular vehicle for detailed ocean mapping

    NASA Astrophysics Data System (ADS)

    Huehnerbach, V.; Murton, B.; Berndt, C.; Garrard, J.; Wollatz-Vogt, M.; Wetzel, G.; Matthiessen, T.

    2013-12-01

    HyBIS is a low-cost, multi-purpose, highly maneuverable, fibre-optic controlled survey and sampling robotic underwater vehicle (RUV) capable of diving to 6000m. Built in the UK by Hydro-Lek Ltd. in collaboration with the National Oceanography Centre, Southampton, it has proven itself during recent discoveries of the deepest hydrothermal vents in the world, at 5100m deep in the Cayman Trough in the Caribbean and habitat mapping of seamounts in the Atlantic and Indian oceans . The vehicle has a modular design, with the top module being a command and power system that comprises power management, cameras, lights, hydraulics, thrusters and telemetry. The lower module can alternatively be a clam-shell sampling grab, a manipulator-arm and tool sled, a winch for instrument recovery, or an ocean bottom seismometer deployment module. Unlike a conventional ROV, HyBIS does not have any floatation, rather it is suspended by its umbilical cable directly from the ship. The advantage of direct suspension is that HyBIS can recover or deploy a payload of up to 700kg, although this comes at the price of reduced maneuverability compared to a 'normal' ROV. During its four years of service, HyBIS has, so far, accumulated an impressive list of achievements: recording over 450 hours of HD video footage, thousands of HD still images, collected geological, biological samples, as well as fluids and gas from over 40 different sites. It has also recovered two different seabed landers containing scientific equipment worth over £300k, and placed Ocean Bottom Seismometers onto the seafloor.