Effect of training and rest on respiratory mechanical properties in racing sled dogs.

PubMed

Davis, Michael; Williamson, Katherine; McKenzie, Erica; Royer, Christopher; Payton, Mark; Nelson, Stuart

2005-02-01

Racing Alaskan sled dogs develop exercise-induced airway inflammation, similar to that reported for elite human athletes participating in cold-weather sports. These human athletes also have airway hyperresponsiveness, but airway function in sled dogs has not been measured. To compare respiratory mechanical properties in trained, rested Alaskan sled dogs with typical laboratory hounds, and to determine whether subsequent training alters respiratory mechanical properties. Nineteen healthy adult Alaskan sled dogs were compared with five healthy adult mixed-breed laboratory hounds. All dogs were rested for at least 4 months before examination. Respiratory mechanical properties were measured while the dogs were anesthetized and ventilated with a piston ventilator. The mean respiratory resistance and compliance measurements for 20 consecutive breaths were used as baseline values immediately before measurement of respiratory reactivity. Respiratory reactivity was the mean of 20 consecutive breaths immediately after the administration of aerosol histamine, expressed as the percentage change in prehistamine measurements. After the initial examinations, the sled dogs were divided into exercised and controls. Exercised dogs were trained for competitive endurance racing. Both groups were examined after 2 and 4 months of training. Alaskan sled dogs had greater respiratory compliance reactivity to histamine (77.47 +/- 8.58% baseline) compared with laboratory dogs (87.60 +/- 9.22% baseline). There was no effect of training on respiratory mechanical properties detected in racing sled dogs. Racing Alaskan sled dogs have airway dysfunction similar to "ski asthma" that persists despite having 4 months of rest. These findings suggest that repeated exercise in cold conditions can lead to airway disease that does not readily resolve with cessation of exercise.

Super-Lattice Light Emitting Diodes (SLEDS) on GaAs

DTIC Science & Technology

2016-03-31

Super-Lattice Light Emitting Diodes (SLEDS) on GaAs Kassem Nabha1, Russel Ricker2, Rodney McGee1, Nick Waite1, John Prineas2, Sydney Provence2...infrared light emitting diodes (LEDs). Typically, the LED arrays are mated with CMOS read-in integrated circuit (RIIC) chips using flip-chip bonding. In...circuit (RIIC) chips using flip-chip bonding. This established technology is called Hybrid-super-lattice light emitting diodes (Hybrid- SLEDS). In

A genetic dissection of breed composition and performance enhancement in the Alaskan sled dog

PubMed Central

2010-01-01

Background The Alaskan sled dog offers a rare opportunity to investigate the development of a dog breed based solely on performance, rather than appearance, thus setting the breed apart from most others. Several established breeds, many of which are recognized by the American Kennel Club (AKC), have been introduced into the sled dog population to enhance racing performance. We have used molecular methods to ascertain the constitutive breeds used to develop successful sled dog lines, and in doing so, determined the breed origins of specific performance-related behaviors. One hundred and ninety-nine Alaskan sled dogs were genotyped using 96 microsatellite markers that span the canine genome. These data were compared to that from 141 similarly genotyped purebred dog breeds. Sled dogs were evaluated for breed composition based on a variety of performance phenotypes including speed, endurance and work ethic, and the data stratified based on population structure. Results We observe that the Alaskan sled dog has a unique molecular signature and that the genetic profile is sufficient for identifying dogs bred for sprint versus distance. When evaluating contributions of existing breeds we find that the Alaskan Malamute and Siberian Husky contributions are associated with enhanced endurance; Pointer and Saluki are associated with enhanced speed and the Anatolian Shepherd demonstrates a positive influence on work ethic. Conclusion We have established a genetic breed profile for the Alaskan sled dog, identified profile variance between sprint and distance dogs, and established breeds associated with enhanced performance attributes. These data set the stage for mapping studies aimed at finding genes that are associated with athletic attributes integral to the high performing Alaskan sled dog. PMID:20649949

Prevalence of diarrhea and enteropathogens in racing sled dogs.

PubMed

McKenzie, E; Riehl, J; Banse, H; Kass, P H; Nelson, S; Marks, S L

2010-01-01

Diarrhea is highly prevalent in racing sled dogs, although the underlying causes are poorly understood. Clostridium perfringens enterotoxin (CPE) and Clostridium difficile Toxin A and B are associated with diarrhea in racing sled dogs. One hundred and thirty-five sled dogs. Freshly voided feces were obtained from 55 dogs before racing and from 80 dogs after 400 miles of racing. Samples were visually scored for diarrhea, mucus, blood, and melena. CPE and C. difficile Toxin A and B were detected by ELISA. Samples were cultured for C. perfringens, C. difficile, Campylobacter, Salmonella, and Escherichia coli O157; Giardia and Cryptosporidium spp. were detected via immunofluorescence. Diarrhea occurred in 36% of dogs during racing, and hematochezia, fecal mucus or melena, or all 3 occurred in 57.5% of dogs. Salmonella was isolated from 78.2% of dogs before racing, and from 71.3% of dogs during racing. C. perfringens and C. difficile were isolated from 100 and 58.2% of dogs before racing, and from 95 and 36.3% of dogs during racing. Dogs were more likely to test positive for CPE during than before racing (18.8 versus 5.5%, P = .021); however, no enteropathogens or their respective toxins were significantly associated with hematochezia or diarrhea. Sled dogs participating in long distance racing have a high prevalence of diarrhea and hematochezia that is not associated with common enteropathogens. It is possible that diarrhea and hematochezia represent the effect of prolonged exercise on the gastrointestinal tract.

A Transformational Curriculum Model: A Wilderness Travel Adventure Dog Sledding in Temagami.

ERIC Educational Resources Information Center

Leckie, Linda

1996-01-01

Personal narrative links elements of a dog sledding trip with the transformational curriculum model as applied to outdoor education. Describes the physical, mental, and spiritual challenges of a seven-day winter camping and dog sledding trip, during which students learned responsibility through experience and natural consequences and realized the…

Lower-limb and trunk muscle activation with back squats and weighted sled apparatus.

PubMed

Maddigan, Meaghan E; Button, Duane C; Behm, David G

2014-12-01

The back squat is a traditional resistance training exercise, whereas the resisted sled exercise is a relatively new resistance exercise. However, as there are no studies comparing muscle activation between the exercises, the objective of this study was to examine activity of leg and trunk muscles for both exercises. Ten healthy resistance-trained men participated in a randomized crossover design study consisting of 2 preparation sessions and 2 testing sessions. Electromyographic (EMG) activity of the rectus femoris, biceps femoris, gastrocnemius, lower erector spinae, and the transversus abdominis/internal obliques (TrA/IO) were monitored during a 20-step maximum push with the weighted sled apparatus and a 10 repetition maximum with a bilateral back squat. There were nonsignificant trends for the rectus femoris (p = 0.092: 8.6-16.7%) and biceps femoris (p = 0.09: 10.5-32.8%) to demonstrate higher activity with the sled and squat exercises, respectively. There were main effects for condition with 61.2% greater gastrocnemius EMG with the sled exercise (p = 0.01) and 74.5% greater erector spinae EMG activity with the squat (p = 0.002). There were no significant differences between the exercises for the TrA/IO. In summary, the sled and squat exercises provided similar EMG activity for the quadriceps, hamstrings, and TrA/IO. The squat provided higher lower erector spinae activation, whereas the sled had superior gastrocnemius activation. Depending on the movement-training specificity of the sport, either exercise may be used in a training program while acknowledging the differences in gastrocnemius and erector spinae activity.

Broadband SLED-based light source (BeST-SLEDTM) and spectrometer

NASA Astrophysics Data System (ADS)

Yadid-Pecht, Orly; Dattner, Yonathan

2016-03-01

A small footprint, low power, cost effective single mode fiber coupled broadband light source and spectrometer is presented. It is based on Super Luminescent Diode (SLED) devices and a compact design enables coverage of the 1250 nm-1750 nm region with a total optical power of 50 mW at the output of the fiber. This Broad Spectrum Tunable Super Luminescent (BeST-SLEDTM) light source can operate at temperatures ranging from -40°C to 60°C, and resides in a custom designed 26-pin package. The fiber is a polarization maintaining fiber with a FC/APC connector at the output. Three variations of the BeST-SLEDTM were developed, BEST-SLED™ Bands, BeST-SLEDTM Tunable and BeST-SLEDTM FTNIR. In the Bands version six SLEDs were packaged allowing for one SLED on at a time or any combination of the SLEDs on. In the Tunable version an Acoustic Optical Tunable Filter (AOTF) was integrated into the package allowing the user to select one wavelength at a time to pass into the fiber with resolution of ~1 nm @1550nm. In the FTNIR version, a Silicon Photonic based interferometer (the Nano-SpecTM) was integrated into the package for a Fourier Transform Near Infrared based Spectrometer and light source. The BeST-SLEDTM is being used in process control applications such as steam quality measurements, oil in water, gas composition and air quality monitoring.

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.

Risk factors and control of intestinal parasite infections in sled dogs in Poland.

PubMed

Bajer, Anna; Bednarska, Malgorzata; Rodo, Anna

2011-02-10

Training and racing constitute serious challenges for working sled dogs. Attainment of the highest levels of stamina and speed are possible only by completely healthy dogs. Infections with nematodes as whipworm Trichuris sp. or hookworms Uncinaria/Ancylostoma can significantly reduce the fitness of working dogs leading to anemia or even to death. In the middle of the racing season, between December 2009 and April 2010, 108 individual fecal samples were collected from 25 sled dog kennels situated in different regions of Poland. Saturated salt flotation was performed for helminth egg detection. The immunofluorescent assay MeriFluor Cryptosporidium/Giardia and nested PCRs on 18S rRNA (Cryptosporidium spp.) and TPI gene (Giardia spp.) were carried out for detection of intestinal protozoa. Overall prevalence of 6 species of intestinal parasites was 68% in sled dogs (73/108). In 51 samples the eggs of a single species of helminth were detected (47%), two nematode species were detected in 13%, three species of nematodes were found in two dogs. The most prevalent helminths were the hookworms Uncinaria/Ancylostoma-identified in 36% of kennels, and in 34% of sled dogs. Toxocara eggs were detected in 36% of kennels, in 17% of dogs. Trichuris sp. eggs were found in 20% of kennels (5/25), in 13% of dogs. Cysts/oocysts of intestinal protozoa were detected in 31% of sled dogs. The most prevalent was Giardia spp. infection-in 54% of kennels [13/24], in 28% of dogs. Cryptosporidium spp. infections were identified in 37.5% of kennels [9/24], in 13% of dogs. Two sequenced Giardia isolates presented 100% homology with G. intestinalis Assemblage C isolate (AY228641.1), specific for dogs. A range of factors was shown to affect the prevalence of intestinal parasites in sled dogs. The highest prevalence of parasites was found among dogs from large kennels (housing >3 dogs), in dogs less than 2 years old, and in kennels, where prophylactic treatment was carried out 1-4 times a year. The

Recovering the Physical Properties of Molecular Gas in Galaxies from CO SLED Modeling

NASA Astrophysics Data System (ADS)

Kamenetzky, J.; Privon, G. C.; Narayanan, D.

2018-05-01

Modeling of the spectral line energy distribution (SLED) of the CO molecule can reveal the physical conditions (temperature and density) of molecular gas in Galactic clouds and other galaxies. Recently, the Herschel Space Observatory and ALMA have offered, for the first time, a comprehensive view of the rotational J = 4‑3 through J = 13‑12 lines, which arise from a complex, diverse range of physical conditions that must be simplified to one, two, or three components when modeled. Here we investigate the recoverability of physical conditions from SLEDs produced by galaxy evolution simulations containing a large dynamical range in physical properties. These simulated SLEDs were generally fit well by one component of gas whose properties largely resemble or slightly underestimate the luminosity-weighted properties of the simulations when clumping due to nonthermal velocity dispersion is taken into account. If only modeling the first three rotational lines, the median values of the marginalized parameter distributions better represent the luminosity-weighted properties of the simulations, but the uncertainties in the fitted parameters are nearly an order of magnitude, compared to approximately 0.2 dex in the “best-case” scenario of a fully sampled SLED through J = 10‑9. This study demonstrates that while common CO SLED modeling techniques cannot reveal the underlying complexities of the molecular gas, they can distinguish bulk luminosity-weighted properties that vary with star formation surface densities and galaxy evolution, if a sufficient number of lines are detected and modeled.

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

7. SHOWING METHOD OF SLEDDING WIND CABLE DOWN YAKI TRAIL ...

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

7. SHOWING METHOD OF SLEDDING WIND CABLE DOWN YAKI TRAIL TO THE BRIDGE, WEIGHT OF CABLE AND DRUM APPROXIMATELY 2200 POUNDS - Kaibab Trail Suspension Bridge, Spanning Colorado River, Grand Canyon, Coconino County, AZ

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.

Optimal Loading for Maximizing Power During Sled-Resisted Sprinting.

PubMed

Cross, Matt R; Brughelli, Matt; Samozino, Pierre; Brown, Scott R; Morin, Jean-Benoit

2017-09-01

To ascertain whether force-velocity-power relationships could be compiled from a battery of sled-resisted overground sprints and to clarify and compare the optimal loading conditions for maximizing power production for different athlete cohorts. Recreational mixed-sport athletes (n = 12) and sprinters (n = 15) performed multiple trials of maximal sprints unloaded and towing a selection of sled masses (20-120% body mass [BM]). Velocity data were collected by sports radar, and kinetics at peak velocity were quantified using friction coefficients and aerodynamic drag. Individual force-velocity and power-velocity relationships were generated using linear and quadratic relationships, respectively. Mechanical and optimal loading variables were subsequently calculated and test-retest reliability assessed. Individual force-velocity and power-velocity relationships were accurately fitted with regression models (R 2 > .977, P < .001) and were reliable (ES = 0.05-0.50, ICC = .73-.97, CV = 1.0-5.4%). The normal loading that maximized peak power was 78% ± 6% and 82% ± 8% of BM, representing a resistance of 3.37 and 3.62 N/kg at 4.19 ± 0.19 and 4.90 ± 0.18 m/s (recreational athletes and sprinters, respectively). Optimal force and normal load did not clearly differentiate between cohorts, although sprinters developed greater maximal power (17.2-26.5%, ES = 0.97-2.13, P < .02) at much greater velocities (16.9%, ES = 3.73, P < .001). Mechanical relationships can be accurately profiled using common sled-training equipment. Notably, the optimal loading conditions determined in this study (69-96% of BM, dependent on friction conditions) represent much greater resistance than current guidelines (~7-20% of BM). This method has potential value in quantifying individualized training parameters for optimized development of horizontal power.

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

High-Performance Plastic Sled Design for Polar Traversing

DTIC Science & Technology

2015-06-01

snow resupply traverses in Antarctica and Greenland tow high- efficiency fuel sleds that consist of flexible fuel bladders strapped to flexi- ble sheets...Foundation, Division of Polar Programs (NSF-PLR), operates over-snow traverses in Antarctica and Greenland to resupply their science stations. The 1030...mile (one way) South Pole Traverse (SPoT) begins at McMurdo Station on Ross Island, travels across the Ross Ice Shelf, up the Leverett Glacier, and

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

capable of testing radome materials in multiple impact simulated rain at Mach 5 is the monorail sled facility at the Holloman Air Force Base, New Mexico...existing 9-in. monorail sled at the Holloman test track, to be structurally adequate for the environment, and to carry samples of the desired shape...direction over a total length of 15,480 m(50,788 ft). For Mach 5 rain erosion tests, the sled operates on a monorail . Braking for these monorail

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.

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

Performance Evaluation of Child Safety Seats in Far-Side Lateral Sled Tests at Varying Speeds

PubMed Central

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

2009-01-01

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. PMID:20184846

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.

Lieutenant Colonel John Stapp Demonstrates the Rocket Sled

NASA Image and Video Library

1956-04-21

Howard Hasbrook volunteers for a demonstration of a scaled-down version of Lieutenant Colonel John Stapp’s rocket sled set up in the hangar at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. In 1945 Stapp, an Air Force medical doctor, volunteered to participate in a deceleration program to study the human body’s tolerance to aircraft crash forces. A 1500-pound sled powered by rockets was installed in 1947 on a section of railroad track in the California desert. Stapp participated in 29 experiments over the next seven years and broke land and deceleration records. These tests studied the effects of acceleration, G-force, deceleration, and wind blast on humans. Stapp suffered broken bones and retinal hemorrhages, but suffered no permanent damage. NACA Lewis was conducting a series of crash impact studies in the mid-1950s using dummies in actual aircraft. Irving Pinkel, the director of the program, and Stapp became friends through their mutual interest in this field. In April 1956 Stapp visited the Cleveland lab to give a talk to the local section of the American Rocket Society that discussed issues relating to the escape of pilots from the cockpit of supersonic jet aircraft. That same week, NACA Lewis’ Pinkel, Gerard Pesman, Merritt Preston, and Dugald Black received the annual Laura Taber Barbour Air Safety Award for their work on the Crash Fire Program. Black and Preston are visible in the crowd in this photograph.

An SNP within the Angiotensin-Converting Enzyme Distinguishes between Sprint and Distance Performing Alaskan Sled Dogs in a Candidate Gene Analysis

PubMed Central

Huson, Heather J.; Byers, Alexandra M.; Runstadler, Jonathan

2011-01-01

The Alaskan sled dog offers a unique mechanism for studying the genetics of elite athletic performance. They are a group of mixed breed dogs, comprised of multiple common breeds, and a unique breed entity seen only as a part of the sled dog mix. Alaskan sled dogs are divided into 2 primary groups as determined by their racing skills. Distance dogs are capable of running over 1000 miles in 10 days, whereas sprint dogs run much shorter distances, approximately 30 miles, but in faster times, that is, 18–25 mph. Finding the genes that distinguish these 2 types of performers is likely to illuminate genetic contributors to human athletic performance. In this study, we tested for association between polymorphisms in 2 candidate genes; angiotensin-converting enzyme (ACE) and myostatin (MSTN) and enhanced speed and endurance performance in 174 Alaskan sled dogs. We observed 81 novel genetic variants within the ACE gene and 4 within the MSTN gene, including a polymorphism within the ACE gene that significantly (P value 2.38 × 10−5) distinguished the sprint versus distance populations. PMID:21846742

DEVELOPMENT OF A NINE INCH DIAMETER, MACH 5.5, MONORAIL, ROCKET SLED.

DTIC Science & Technology

A nine inch diameter monorail rocket sled was designed, fabricated and tested at Holloman Air Force Base. The vehicle was designed to allow easy...replacement of appendages which were subject to severe aerodynamic heating and/or high wear rates. The monorail vehicle as described was shown to be

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.

Biomechanical Profiles When Towing a Sled and Wearing a Weighted Vest Once Cleared for Sports Post-ACL Reconstruction.

PubMed

Hartigan, Erin; Lawrence, Michael; Murray, Thomas; Shaw, Bernadette; Collins, Erin; Powers, Kaitlin; Townsend, James

2016-09-01

Though rehabilitation attempts to correct "stiff knee gait" and control for dynamic limb valgus after anterior cruciate ligament reconstruction (ACLR), impaired biomechanics often persist when an individual is cleared to return to sport (RTS). Reduced knee extension moments (KEMs) and knee flexion angles (KFAs) often continue. While at the hip, increased hip adduction angles (HADDAs) and hip internal rotation angles (HIRAs) often persist in spite of dynamic hip stabilization exercises. Sled towing and weighted vest tasks increase KEM and hip extension moments (HEMs) in healthy individuals, yet biomechanical profiles during these tasks after ACLR are unknown. Weighted gait will increase KEM, HEM, hip abduction moments (HABDMs), and hip external rotation moments (HERMs) and will not increase unwanted biomechanics (limb asymmetries, HIRA, HADDA) compared with normal gait. Controlled laboratory study. Level 4. Fourteen men and 24 women who were 5 to 12 months after ACLR, had no concomitant ligament injuries, and were cleared to RTS were recruited. Sexes were evaluated independently given the sex-specific incidence to ACL injury, reinjury, and gait responses to certain interventions. Joint moment impulses and peak angles over the first 25% of stance were compared between limbs and across tasks (eg, unweighted gait, sled 50% body weight [BW], and vest 50% BW). Men showed that weighted gait increased KEM, HEM, HERM, HADBM (vest only), HADDA, HIRA (sled only), and KFA. Asymmetrical KEM and KFA existed across tasks. Women showed that weighted gait increased KEM, HEM, HERM, HADBM (vest only), HFA (sled only), HADDA, and KFA. Asymmetrical KEM, HEM, HIRA, and KFA (sled only) existed across tasks. Weighted gait generally increased joint moments. Unwanted biomechanics were unique for each weighted gait task. Though joint moments increased, both tasks created unwanted biomechanics after ACLR. Persistent hip (women only) and KEM asymmetries across tasks when cleared to RTS are

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

Small female rib cage fracture in frontal sled tests.

PubMed

Shaw, Greg; Lessley, David; Ash, Joseph; Poplin, Jerry; McMurry, Tim; Sochor, Mark; Crandall, Jeff

2017-01-02

The 2 objectives of this study are to (1) examine the rib and sternal fractures sustained by small stature elderly females in simulated frontal crashes and (2) determine how the findings are characterized by prior knowledge and field data. A test series was conducted to evaluate the response of 5 elderly (average age 76 years) female postmortem human subjects (PMHS), similar in mass and size to a 5th percentile female, in 30 km/h frontal sled tests. The subjects were restrained on a rigid planar seat by bilateral rigid knee bolsters, pelvic blocks, and a custom force-limited 3-point shoulder and lap belt. Posttest subject injury assessment included identifying rib cage fractures by means of a radiologist read of a posttest computed tomography (CT) and an autopsy. The data from a motion capture camera system were processed to provide chest deflection, defined as the movement of the sternum relative to the spine at the level of T8.  A complementary field data investigation involved querying the NASS-CDS database over the years 1997-2012. The targeted cases involved belted front seat small female passenger vehicle occupants over 40 years old who were injured in 25 to 35 km/h delta-V frontal crashes (11 to 1 o'clock). Peak upper shoulder belt tension averaged 1,970 N (SD = 140 N) in the sled tests. For all subjects, the peak x-axis deflection was recorded at the sternum with an average of -44.5 mm or 25% of chest depth. The thoracic injury severity based on the number and distribution of rib fractures yielded 4 subjects coded as Abbreviated Injury Scale (AIS) 3 (serious) and one as AIS 5 (critical). The NASS-CDS field data investigation of small females identified 205 occupants who met the search criteria. Rib fractures were reported for 2.7% of the female occupants. The small elderly test subjects sustained a higher number of rib cage fractures than expected in what was intended to be a minimally injurious frontal crash test condition. Neither field studies nor

Occupant responses in conventional and ABTS seats in high-speed rear sled tests.

PubMed

Viano, David C; Parenteau, Chantal S; Burnett, Roger; Prasad, Priya

2018-01-02

This study compared biomechanical responses of a normally seated Hybrid III dummy on conventional and all belts to seat (ABTS) seats in 40.2 km/h (25 mph) rear sled tests. It determined the difference in performance with modern (≥2000 MY) seats compared to older (<2000 MY) seats and ABTS seats. The seats were fixed in a sled buck subjected to a 40.2 km/h (25 mph) rear sled test. The pulse was a 15 g double-peak acceleration with 150 ms duration. The 50th percentile Hybrid III was lap-shoulder belted in the FMVSS 208 design position. The testing included 11 <2000 MY, 8 ≥2000 MY, and 7 ABTS seats. The dummy was fully instrumented, including head accelerations, upper and lower neck 6-axis load cells, chest acceleration, thoracic and lumbar spine load cells, and pelvis accelerations. The peak responses were normalized by injury assessment reference values (IARVs) to assess injury risks. Statistical analysis was conducted using Student's t test. High-speed video documented occupant kinematics. Biomechanical responses were lower with modern (≥2000 MY) seats than older (<2000 MY) designs. The lower neck extension moment was 32.5 ± 9.7% of IARV in modern seats compared to 62.8 ± 31.6% in older seats (P =.01). Overall, there was a 34% reduction in the comparable biomechanical responses with modern seats. Biomechanical responses were lower with modern seats than ABTS seats. The lower neck extension moment was 41.4 ± 7.8% with all MY ABTS seats compared to 32.5 ± 9.7% in modern seats (P =.07). Overall, the ABTS seats had 13% higher biomechanical responses than the modern seats. Modern (≥2000 MY) design seats have lower biomechanical responses in 40.2 km/h rear sled tests than older (<2000 MY) designs and ABTS designs. The improved performance is consistent with an increase in seat strength combined with improved occupant kinematics through pocketing of the occupant into the seatback, higher and more forward head restraint, and other design changes. The methods

Effects of a synbiotic on fecal quality, short-chain fatty acid concentrations, and the microbiome of healthy sled dogs

PubMed Central

2013-01-01

Background Sled dogs commonly suffer from diarrhea. Although multiple etiologies exist there are limited field studies using synbiotics as a supplement to prevent or treat diarrhea. The objective of this study was to examine alterations in fecal quality, short-chain fatty acids (SCFA), and the fecal microbiome in two groups of training sled dogs fed a synbiotic or microcrystalline cellulose placebo. Twenty clinically healthy training sled dogs randomized into two cohorts (9 synbiotic-fed, 8 placebo-fed) for a 6 week prospective study were examined. Fecal pH and fecal short chain fatty acid (SCFA) concentrations were measured and tag-encoded FLX 16S rDNA amplicon pyrosequencing (bTEFAP) and quantitative real-time PCR were performed at baseline (10 d prior to the study) and after 2 weeks of treatment with a total treatment time of 6 weeks. Fecal scores for all dogs were assessed at baseline and every day for 6 wk after initiation of treatment. Results Alterations in the fecal microbiome were observed with a significant rise in Lactobacillaceae in the synbiotic group (P = 0.004) after 2 wk of treatment. A positive correlation was found between Lactobacillaceae and overall butyrate concentration (R = 0.62, p = 0.011) in all dogs. After 5 wk of treatment, there was an improved fecal score and fewer days of diarrhea (Χ2 = 5.482, P = 0.019) in the dogs given synbiotic, which coincided with a presumed contagious outbreak shared by all dogs in the study. Conclusions Use of this synbiotic results in an increase in presumed beneficial bacterial flora of the host colon which was associated with a decrease in the prevalence of diarrhea in training sled dogs. PMID:24313995

Effects of a synbiotic on fecal quality, short-chain fatty acid concentrations, and the microbiome of healthy sled dogs.

PubMed

Gagné, Jason W; Wakshlag, Joseph J; Simpson, Kenneth W; Dowd, Scot E; Latchman, Shalini; Brown, Dawn A; Brown, Kit; Swanson, Kelly S; Fahey, George C

2013-12-05

Sled dogs commonly suffer from diarrhea. Although multiple etiologies exist there are limited field studies using synbiotics as a supplement to prevent or treat diarrhea. The objective of this study was to examine alterations in fecal quality, short-chain fatty acids (SCFA), and the fecal microbiome in two groups of training sled dogs fed a synbiotic or microcrystalline cellulose placebo. Twenty clinically healthy training sled dogs randomized into two cohorts (9 synbiotic-fed, 8 placebo-fed) for a 6 week prospective study were examined. Fecal pH and fecal short chain fatty acid (SCFA) concentrations were measured and tag-encoded FLX 16S rDNA amplicon pyrosequencing (bTEFAP) and quantitative real-time PCR were performed at baseline (10 d prior to the study) and after 2 weeks of treatment with a total treatment time of 6 weeks. Fecal scores for all dogs were assessed at baseline and every day for 6 wk after initiation of treatment. Alterations in the fecal microbiome were observed with a significant rise in Lactobacillaceae in the synbiotic group (P = 0.004) after 2 wk of treatment. A positive correlation was found between Lactobacillaceae and overall butyrate concentration (R = 0.62, p = 0.011) in all dogs. After 5 wk of treatment, there was an improved fecal score and fewer days of diarrhea (Χ2 = 5.482, P = 0.019) in the dogs given synbiotic, which coincided with a presumed contagious outbreak shared by all dogs in the study. Use of this synbiotic results in an increase in presumed beneficial bacterial flora of the host colon which was associated with a decrease in the prevalence of diarrhea in training sled dogs.

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 Central

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

2012-01-01

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 correlating 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 principle 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). Further, we identified eight regions with the genomic signal either from 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 association 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. PMID:22105876

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.

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

SNR of swept SLEDs and swept lasers for OCT (Conference Presentation)

NASA Astrophysics Data System (ADS)

Johnson, Bart C.; Atia, Walid; Flanders, Dale; Kuznetsov, Mark; Goldberg, Brian; Kemp, Nate; Whitney, Peter

2016-03-01

A back-to-back comparison of a tunable narrow-band SLED (TSLED) and a swept laser are made for OCT applications. Both are 1310 nm sources sweeping at 50 kHz over a 100 nm tuning range and have similar coherence lengths. The TSLED consists of a seed SOA and two amplification SOAs. The ASE is filtered twice by a tunable MEMS Fabry Perot in a polarization multiplexed double-pass arrangement on either side of the middle SOA. This allows very long coherence lengths to be achieved. A fundamental issue with a SLED is that the RIN is proportional to 1/Linewidth, meaning that the longer the coherence length, the higher the RIN. High RIN also leads to increased clock jitter. Most swept source SNR calculations assume that the noise is independent of the amplitude of the signal light: The higher the signal, the higher the SNR. We show that in the case of the TSLED, that the high signal RIN and clock jitter give rise to additional noises that scale with signal power. This leads to an SNR limit in the case of the TSLED: The higher the signal, the higher the noise, so the SNR reaches a limit. While the TSLED has respectable sensitivity, the SNR limit causes noise streaks in an image where the A-line has a high reflectivity point. The laser, which is shot noise limited, does not exhibit this effect. This is illustrated with SNR data and side-by-side images taken with the two sources.

Sled-Mounted Geophone Arrays for Near-Surface (0-4m) Seismic Profiling in Highly-attenuating Sedimentary Facies: Atchafalaya Basin Indian Bayou, Louisiana

NASA Astrophysics Data System (ADS)

Lorenzo, J. M.; Saanumi, A. A.; Westbrook, C. C.; Egnew, S. F.; Bentley, S. J.

2004-12-01

Towed land-geophone seismic arrays have the potential to increase markedly the efficiency for collecting near-surface (0-100m) high-resolution seismic data, but viable cases are few and have been limited to a narrow range of near-surface sedimentary facies. During November 2003 through June 2004 we conducted extensive seismic tests with traditional geophones mounted on low-cost Π -shaped sleds. We targeted human habitation surfaces within the upper few meters of a crevasse splay complex in the Atchafalaya Basin study area, Indian Bayou Wildlife Management Area, Louisiana, U.S. For seismic-to-core correlation, sealed, continuous test cores were run through a multi-sensor to test for magnetic susceptibility, bulk sediment density and electrical resistivity. We compared 24-channel seismic data using a variety of seismic source-receiver combinations. Sources comprised a 12-gauge pipe-gun, a 0.22 caliber-powered piston gun, an accelerated weight drop, and a small claw hammer. Commercial blanks, 2g-black-powder, and primer-only shells were fired by the pipe gun. Receivers included 100-Hz vertical-, and 14-Hz-horizontal-component geophones. For comparison, both ground-planted and geophones mounted on wooden and iron sleds 0.3 and 1.2m long respectively. Geophones mounted on steel sleds produced data of adequate quality. Whereas traditional ground-planted geophones showed better data quality, time and cost efficiency make mounted phones more feasible for regional studies as traditional arrays are prohibitively expensive. Because of the high seismic attenuation, only horizontal-component geophones mounted on heavy (9-kg) steel sleds provided useful data, although the shallowest reflection observed in the shear wave data came from a boundary at ~ 19m depth, too far below the target depth of 4-5 m. Instead, we forward-modeled refraction traveltime data to derive the acoustic and SH velocity structure.

Non-censored rib fracture data during frontal PMHS sled tests.

PubMed

Kemper, Andrew R; Beeman, Stephanie M; Porta, David J; Duma, Stefan M

2016-09-01

The purpose of this study was to obtain non-censored rib fracture data due to three-point belt loading during dynamic frontal post-mortem human surrogate (PMHS) sled tests. The PMHS responses were then compared to matched tests performed using the Hybrid-III 50(th) percentile male ATD. Matched dynamic frontal sled tests were performed on two male PMHSs, which were approximately 50(th) percentile height and weight, and the Hybrid-III 50(th) percentile male ATD. The sled pulse was designed to match the vehicle acceleration of a standard sedan during a FMVSS-208 40 kph test. Each subject was restrained with a 4 kN load limiting, driver-side, three-point seatbelt. A 59-channel chestband, aligned at the nipple line, was used to quantify the chest contour, anterior-posterior sternum deflection, and maximum anterior-posterior chest deflection for all test subjects. The internal sternum deflection of the ATD was quantified with the sternum potentiometer. For the PMHS tests, a total of 23 single-axis strain gages were attached to the bony structures of the thorax, including the ribs, sternum, and clavicle. In order to create a non-censored data set, the time history of each strain gage was analyzed to determine the timing of each rib fracture and corresponding timing of each AIS level (AIS = 1, 2, 3, etc.) with respect to chest deflection. Peak sternum deflection for PMHS 1 and PMHS 2 were 48.7 mm (19.0%) and 36.7 mm (12.2%), respectively. The peak sternum deflection for the ATD was 20.8 mm when measured by the chest potentiometer and 34.4 mm (12.0%) when measured by the chestband. Although the measured ATD sternum deflections were found to be well below the current thoracic injury criterion (63 mm) specified for the ATD in FMVSS-208, both PMHSs sustained AIS 3+ thoracic injuries. For all subjects, the maximum chest deflection measured by the chestband occurred to the right of the sternum and was found to be 83.0 mm (36.0%) for PMHS 1, 60.6 mm (23.9%) for PMHS 2

Thoracic and lumbar spine responses in high-speed rear sled tests.

PubMed

Viano, David C; Parenteau, Chantal S; Burnett, Roger

2018-07-04

This study analyzed thoracic and lumbar spine responses with in-position and out-of-position (OOP) seated dummies in 40.2 km/h (25 mph) rear sled tests with conventional and all-belts-to-seat (ABTS) seats. Occupant kinematics and spinal responses were determined with modern (≥2000 MY), older (<2000 MY), and ABTS seats. The seats were fixed in a sled buck subjected to a 40.2 km/h (25 mph) rear sled test. The pulse was a 15 g double-peak acceleration with 150 ms duration. The 50th percentile Hybrid III was lap-shoulder belted in the FMVSS 208 design position or OOP, including leaning forward and leaning inboard and forward. There were 26 in-position tests with 11 <2000 MY, 8 ≥2000 MY, and 7 ABTS and 14 OOP tests with 6 conventional and 8 ABTS seats. The dummy was fully instrumented. This study addressed the thoracic and lumbar spine responses. Injury assessment reference values are not approved for the thoracic and lumbar spine. Conservative thresholds exist. The peak responses were normalized by a threshold to compare responses. High-speed video documented occupant kinematics. The extension moments were higher in the thoracic than lumbar spine in the in-position tests. For <2000 MY seats, the thoracic extension moment was 76.8 ± 14.6% of threshold and the lumbar extension moment was 50.5 ± 17.9%. For the ≥2000 MY seats, the thoracic extension moment was 54.2 ± 26.6% of threshold and the lumbar extension moment was 49.8 ± 27.7%. ABTS seats provided similar thoracic and lumbar responses. Modern seat designs lowered thoracic and lumbar responses. For example, the 1996 Taurus had -1,696 N anterior lumbar shear force and -205.2 Nm extension moment. There was -1,184 N lumbar compression force and 1,512 N tension. In contrast, the 2015 F-150 had -500 N shear force and -49.7 Nm extension moment. There was -839 N lumbar compression force and 535 N tension. On average, the 2015 F-150 had 40% lower lumbar spine responses than the 1996 Taurus. The OOP tests had

Toxicokinetics of mercury in blood compartments and hair of fish-fed sled dogs

PubMed Central

2011-01-01

Background Understanding mercury (Hg) distribution in blood and the importance of hair as an excretory pathway is critical for evaluating risk from long term dietary Hg exposure. The major objective of this study was to characterize changes in total Hg concentrations in specific blood compartments and hair over time due to long term piscivory. Methods Eight sled dogs (Canis lupus familiaris) were fed either a fish and kibble diet (n = 4), or a fish-free control diet (n = 4) for 12 weeks. Concentrations of Hg were monitored throughout the exposure period, and for 10 weeks post exposure, until Hg concentrations in all blood compartments of one of the exposed dogs dropped below detection limit. Additionally, foreleg hair was sampled during acclimation and weeks 0 and 12. Results Hg was detected primarily in whole blood and packed cells, although it was sporadically detected at low concentrations in plasma and serum in two of the fish fed dogs. Dogs ingested an estimated average of 13.4 ± 0.58 μg Hg per kg body weight per day. Hg was detectable in whole blood and packed cells within a week of exposure. Detected concentrations continued to rise until plateauing at approximately 3-6 weeks of exposure at a mean of 9.2 ± 1.97 ng/g (ppb) in whole blood. Hg concentration decreased post exposure following 1st order elimination. The mean half-life (t1/2) in whole blood for Hg was 7 weeks. Mean Hg in hair for the fish-fed dogs at week 12 was 540 ± 111 ppb and was significantly greater (about 7-fold) than the Hg hair concentration for the control dogs. The hair to blood ratio for Hg in fish-fed dogs was 59.0 ± 7.6:1. Conclusions This study found the sled dog model to be an effective method for investigating and characterizing blood Hg distribution (whole blood, serum, plasma, packed cells) and toxicokinetics associated with a piscivorous diet, especially for Hg-exposed fur bearing mammals (such as polar bears). Although hair excretion and hair to blood Hg ratios were not

Influence of endurance and sprinting exercise on plasma adiponectin, leptin and irisin concentrations in racing Greyhounds and sled dogs.

PubMed

Bell, M A; Levine, C B; Downey, R L; Griffitts, C; Mann, S; Frye, C W; Wakshlag, J J

2016-05-01

The objective of this study was to assess the effects of both short-term anaerobic exercise and long-term aerobic exercise on leptin, adiponectin and irisin concentrations in both sprint and endurance canine athletes. Prospective field trial repeated measures. The 25 racing Greyhounds were run over 400 m, with blood samples collected prior to exercise and at 10 min and 120 min after exercise. The 16 sled dogs were run an average of 3.5-5 h/day on 5 out of 8 days of stage stop racing competition, with assessment on days 0, 2 and 8. Baseline leptin concentrations were found to be lower than previously recorded values of domestic dogs, possibly because of a lower body fat content in athletes, with concentrations in sled dogs being slightly higher than those in Greyhounds. Baseline adiponectin concentrations in both groups of dogs, on average, were lower than most previously recorded values in domestic dogs; although unexpected, these findings may be attributed to differences in body fat content of the study population. Endurance exercise in sled dogs resulted in a persistent decrease in leptin that appears to be independent of race-associated weight loss, with no appreciable changes in adiponectin or irisin concentrations. The anaerobic exercise of Greyhounds produced no detectable changes in leptin and adiponectin concentrations; however, a significant rise in irisin 10 min post-exercise may be a compensatory mechanism for restoration of ATP homeostasis in skeletal muscle. © 2016 Australian Veterinary Association.

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.

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 amore » single 50-MW.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Ejection injury to the spine in small aviators: sled tests of manikins vs. post mortem specimens.

PubMed

Salzar, Robert S; Bolton, James R; Crandall, Jeff R; Paskoff, Glenn R; Shender, Barry S

2009-07-01

This study presents the results of seven aerospace manikin and three post mortem human surrogate (PMHS) horizontal deceleration sled tests. The objective of this study was to establish a body of baseline data that examines the ability of small (fifth percentile) manikins to predict whole-body kinematics associated with aircraft ejection, and whether currently available head and neck injury criteria are applicable in these situations. Subjects were exposed to a short-duration local z-axis sled pulse while horizontally seated and restrained in an ejection seat. Test subjects included instrumented fifth percentile female and male manikins, and two small (163.8 cm, 48.3 kg; 143.5 cm, 48.6 kg) female and one small (166.2 cm, 54.3 kg) male PMHS. The anterior (local x-axis) translations of the PMHS heads were less than those observed in the manikin tests, but the local z-axis translations of the PMHS heads were greater than those of the manikins. Z-axis translations of the manikins' T1 were generally similar to those of the PMHS T1, but the anterior x-axis translations of T1 were greater in the PMHS. The neck injury criterion (Nij) tended to under-predict observed injury (primarily ruptures of the posterior ligaments at C4-5, T2-3), and the Beam Criterion (BC) tended to over-predict observed injury for small occupants. The USN/USAF neck injury criteria (NIC) performed best in predicting the observed injuries. Present manikin designs do not predict the kinematics of PMHS in ejection tests. Further refinement of existing injury criteria is required to accurately predict location and severity of ejection-induced injuries.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessment of serum antibody titers against canine distemper virus, canine adenovirus type II, and canine parvovirus in Alaskan sled dogs before and after a long-distance race.

PubMed

Banse, Heidi E; McKenzie, Erica C; Nelson, Stuart; Hinchcliff, Kenneth W

2008-06-01

To determine serum antibody titers against canine distemper virus (CDV), canine adenovirus type II (CAV-2), and canine parvovirus (CPV) in trained sled dogs prior to and after completion of a long-distance race. Prospective cohort study. 195 Alaskan sled dogs (from 18 kennels) that participated in the 2006 Iditarod Trail Race. All 1,323 dogs participating in the race had been vaccinated against the 3 viruses at 19 to 286 days prior to initial blood sample collection (obtained within the month preceding the race). Within 12 hours of race completion, blood samples were collected from 195 dogs (convenience sample) and matched with each dog's prerace sample. Serum antibody titers (90% confidence intervals [CIs]) were determined via serum neutralization assays. After racing, geometric mean titers against CDV and CPV were significantly higher (2,495 [90% CI, 321 to 16,384] and 6,323 [90% CI, 512 to 32,768], respectively) than prerace values (82 [90% CI, 11 to 362] and 166 [90% CI, 32 to 1,024], respectively). Sixty-one of 194 (31.4%) dogs had > or = 4-fold increases in anti-CPV antibody titers after racing. Prerace serum antibody titers against CDV, CPV, and CAV-2 varied significantly by sled team but were not associated with time since vaccination. Postrace increases in serum anti-CDV and anti-CPV antibody titer might reflect exposure of dogs to these agents immediately before or during racing. Dogs had no clinical signs of CDV-, CAV-2-, or CPV-associated disease; therefore, the clinical importance of these titer changes is uncertain.

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.

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of anthropometry on the kinematics of the cervical spine and the risk of injury in sled tests in female volunteers.

PubMed

Dehner, Christoph; Schick, Sylvia; Arand, Markus; Elbel, Martin; Hell, Wolfram; Kramer, Michael

2008-07-01

The objective of this study was to investigate the influence of anthropometric data on the kinematics of the cervical spine and the risk factors for sustaining a neck injury during rear-end collisions occurring in a sled test. A rear-end collision with a velocity change (DeltaV) of 6.3 km/h was simulated in a sled test with eight healthy female subjects. The study analysed the association of anthropometric data with the initial distance between the head and the head restraint, defined kinematic characteristics, the neck injury criterion (NIC) and the neck injury criterion minor (NICmin). The head circumference is negatively associated (r=-0.598) with the initial distance between the head and the head restraint, the maximal head extension (r=-0.687) and the maximal dorsal angular head acceleration (r=-0.633). The body weight (r=0.800), body height (r=0.949) and thorax circumference (r=0.632) are positively associated with the maximal ventral head translation. The neck length correlates positively with the NIC (r=0.826) and negatively with the NICmin (r=-0.797). Anthropometric factors influence the kinematics of the cervical spine and the risk of injury. A high risk of injury may be assumed for individuals with a small head circumference, long neck, tall body height and high body weight.

Protection of children in forward-facing child restraint systems during oblique side impact sled tests: Intrusion and tether effects.

PubMed

Hauschild, Hans W; Humm, John R; Pintar, Frank A; Yoganandan, Narayan; Kaufman, Bruce; Kim, Jinyong; Maltese, Matthew R; Arbogast, Kristy B

2016-09-01

Testing was conducted to quantify the kinematics, potential for head impact, and influence on head injury metrics for a center-seated Q3s in a forward-facing child restraint system (FFCRS) in oblique impacts. The influences of a tether and intruded door on these measures were explored. Nine lateral oblique sled tests were conducted on a convertible forward-facing child restraint seat (FFCRS). The FFCRSs were secured to a bench seat from a popular production small SUV at the center seating position utilizing the lower anchor and tether for children (LATCH). The vehicle seat was fixed on the sled carriage at 60° and 80° from full frontal (30° and 10° forward rotation from pure lateral) providing an oblique lateral acceleration to the Q3s and FFCRS. A structure simulating an intruded door was mounted to the near (left) side of vehicle seat. The sled input acceleration was the proposed FMVSS 213 lateral pulse scaled to a 35 km/h delta-V. Tests were conducted with and without the tether attached to the FFCRS. Results indicate the influence of the tether on kinematics and injury measures in oblique side impact crashes for a center- or far-side-seated child occupant. All tests without a tether resulted in head contact with the simulated door, and 2 tests at the less oblique angle (80°) with a tether also resulted in head contact. No head-to-door contact was observed in 2 tests utilizing a tether. High-speed video analysis showed that the head moved beyond the CRS head side wings and made contact with the simulated intruded door. Head injury criterion (HIC) 15 median values were 589 without the tether vs. 332 with the tether attached. Tests utilizing a tether had less lateral head excursion than tests without a tether (median 400 vs. 442 mm). These tests demonstrate the important role of the tether in controlling head excursion for center- or far-side-seated child occupants in oblique side impact crashes and limiting the head injury potential with an intruded door

Assessing child belt fit, volume II : effect of restraint configuration, booster seat designs, seating procedure, and belt fit on the dynamic response of the hybrid III 10-year-old ATD in sled tests.

DOT National Transportation Integrated Search

2008-09-01

A total of 49 dynamic sled tests were performed with the Hybrid III 10YO to examine issues relating to child belt fit. The goals of these tests were to evaluate ATD response to realistic belt geometries and belt fit, develop methods for accurate, rep...

Occupant kinematics of the Hybrid III, THOR-M, and postmortem human surrogates under various restraint conditions in full-scale frontal sled tests.

PubMed

Albert, Devon L; Beeman, Stephanie M; Kemper, Andrew R

2018-02-28

The objective of this research was to compare the occupant kinematics of the Hybrid III (HIII), THOR-M, and postmortem human surrogates (PMHS) during full-scale frontal sled tests under 3 safety restraint conditions: knee bolster (KB), knee bolster and steering wheel airbag (KB/SWAB), and knee bolster airbag and steering wheel airbag (KBAB/SWAB). A total of 20 frontal sled tests were performed with at least 2 tests performed per restraint condition per surrogate. The tests were designed to match the 2012 Toyota Camry New Car Assessment Program (NCAP) full-scale crash test. Rigid polyurethane foam surrogates with compressive strength ratings of 65 and 19 psi were used to simulate the KB and KBAB, respectively. The excursions of the head, shoulders, hips, knees, and ankles were collected using motion capture. Linear acceleration and angular velocity data were also collected from the head, thorax, and pelvis of each surrogate. Time histories were compared between surrogates and restraint conditions using ISO/TS 18571. All surrogates showed some degree of sensitivity to changes in restraint condition. For example, the use of a KBAB decreased the pelvis accelerations and the forward excursions of the knees and hips for all surrogates. However, these trends were not observed for the thorax, shoulders, and head, which showed more sensitivity to the presence of a SWAB. The average scores computed using ISO/TS 18571 for the HIII/PMHS and THOR-M/PMHS comparisons were 0.527 and 0.518, respectively. The HIII had slightly higher scores than the THOR-M for the excursions (HIII average = 0.574; THOR average = 0.520). However, the THOR-M had slightly higher scores for the accelerations and angular rates (HIII average = 0.471; THOR average = 0.516). The data from the current study showed that both KBABs and SWABs affected the kinematics of all surrogates during frontal sled tests. The results of the objective rating analysis indicated that the HIII and THOR-M had comparable

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.

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 × 10 6 (bp) 2 s −1. pVIc is a ‘molecular sled,’ because it can slide heterologous cargos along DNA,more » 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.« less

Babesia canis and tick-borne encephalitis virus (TBEV) co-infection in a sled dog.

PubMed

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

2013-01-01

Sporting dogs, including sled dogs, are particularly prone to tick-borne infection either due to training/racing in forest areas or through visits to endemic areas. The aim was to present tick-borne infections in a 6-dog racing team after a race in Estonia. On the 4th day after return to Poland, the first dog presented with babesiosis symptoms and was diagnosed and treated accordingly. Next morning, the dog showed neurological symptoms and was diagnosed with tick-borne encephalitis (TBE). Diagnosis was confirmed by a high level of IgG antibodies (922 IU/ml), detected in serum 3 months later. The second dog presented with babesiosis symptoms on the 7th day after return. Babesia DNA was extracted from blood, amplified and sequenced to answer the question of whether the dogs became infected during the race in Estonia or in Poland. Sequencing of a fragment of Babesia 18S rDNA revealed that these two isolates were identical to one another and closely related to the B. canis sequence originally isolated from the dog and Dermacentor reticulatus ticks in Poland. Thus, this is the first confirmed case of B.canis and TBEV co-infection and first confirmed case of TBE in a dog in Poland.

Sleep recovery in participants after racing in the Finnmarkslop - Europe's longest dog‑sled race.

PubMed

Calogiuri, Giovanna; Rossi, Alessio; Formenti, Damiano; Weydahl, Andi

2017-01-01

During the dog-sled race, the Finnmarkslop (FL), which lasts up to 7 days, participants get little sleep and what they get is fragmented; concerns have been raised about proper sleep recovery. The aim of this study was to examine awareness of sleep deprivation by FL participants and post-race sleep recovery after completion of the race. A total of 55 participants responded to an online survey 1 week and 1 month after the race; this measured the following factors: their awareness of sleep loss and possible strategies for recovery; their sleep-wake patterns using a Pittsburgh Sleep Questionnaire Index; and possible changes in respondents' sleep-wake patterns compared with their regular routines. During the FL, participants slept about 3-4 hours a day. Many were not aware of the accumulated sleep debt and did not engage in strategies to make up the loss. Insufficient levels of sleep and impoverished sleep quality were observed after the race, especially among those who were engaged in the FL for a longer period. Alertness levels were affected 1 week after the race. Among participants in the FL, the lack of awareness of sleep debt and insufficient sleep recovery could lead to health consequences. Those engaged in the race for longer should be more cautious during the recovery process because of possible sleep problems occurring after the race. Educational campaigns and easy access to professional support should be provided for participants in this type of sporting event.

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.

Human occupants in low-speed frontal sled tests: effects of pre-impact bracing on chest compression, reaction forces, and subject acceleration.

PubMed

Kemper, Andrew R; Beeman, Stephanie M; Madigan, Michael L; Duma, Stefan M

2014-01-01

The purpose of this study was to investigate the effects of pre-impact bracing on the chest compression, reaction forces, and accelerations experienced by human occupants during low-speed frontal sled tests. A total of twenty low-speed frontal sled tests, ten low severity (∼2.5g, Δv=5 kph) and ten medium severity (∼5g, Δv=10 kph), were performed on five 50th-percentile male human volunteers. Each volunteer was exposed to two impulses at each severity, one relaxed and the other braced prior to the impulse. A 59-channel chestband, aligned at the nipple line, was used to quantify the chest contour and anterior-posterior sternum deflection. Three-axis accelerometer cubes were attached to the sternum, 7th cervical vertebra, and sacrum of each subject. In addition, three linear accelerometers and a three-axis angular rate sensor were mounted to a metal mouthpiece worn by each subject. Seatbelt tension load cells were attached to the retractor, shoulder, and lap portions of the standard three-point driver-side seatbelt. In addition, multi-axis load cells were mounted to each interface between the subject and the test buck to quantify reaction forces. For relaxed tests, the higher test severity resulted in significantly larger peak values for all resultant accelerations, all belt forces, and three resultant reaction forces (right foot, seatpan, and seatback). For braced tests, the higher test severity resulted in significantly larger peak values for all resultant accelerations, and two resultant reaction forces (right foot and seatpan). Bracing did not have a significant effect on the occupant accelerations during the low severity tests, but did result in a significant decrease in peak resultant sacrum linear acceleration during the medium severity tests. Bracing was also found to significantly reduce peak shoulder and retractor belt forces for both test severities, and peak lap belt force for the medium test severity. In contrast, bracing resulted in a significant

How have changes in front air bag designs affected frontal crash death rates? An update.

PubMed

Teoh, Eric R

2014-01-01

Provide updated death rates comparing latest generations of frontal air bags in fatal crashes. Rates of driver and right-front passenger deaths in frontal crashes per 10 million registered vehicle years were compared using Poisson marginal structural models for passenger vehicles equipped with air bags certified as advanced and compliant (CAC), sled-certified air bags with advanced features, and sled-certified air bags without any advanced features. Analyses of driver death rates were disaggregated by age group, gender, and belt use. CAC air bags were associated with slightly elevated frontal crash death rates for both drivers and right-front passengers compared to sled-certified air bags with advanced features, but the differences were not statistically significant. Sled-certified air bags with advanced features were associated with significant benefits for drivers and for right-front passengers compared to sled-certified air bags without advanced features. CAC air bags were associated with a significant increase in belted driver death rate and a comparable but nonsignificant decrease in unbelted driver death rate compared to sled-certified air bags with advanced features. Sled-certified air bags with advanced features were associated with a nonsignificant 2 percent increase in belted driver death rate and a significant 26 percent decrease in unbelted driver death rate, relative to sled-certified air bags without advanced features. Implementing advanced features in sled-certified air bags was beneficial overall to drivers and right-front passengers with sled-certified air bags. No overall benefit was observed for CAC air bags compared to sled-certified air bags with advanced features. Further study is needed to understand the apparent reduction in belted driver protection observed for CAC air bags.

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.

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

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

1. NORTHWEST FRONT AND SOUTHWEST SIDE, SHOWING LOCATION OF BUILDING ...

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

1. NORTHWEST FRONT AND SOUTHWEST SIDE, SHOWING LOCATION OF BUILDING 0520 WEST OF FIRING CONTOL BLOCK HOUSE (BLDG. 0545), BETWEEN SLED TRACK AND CAMERA ACCESS ROAD. - Edwards Air Force Base, South Base Sled Track, Observation Block House, Station "O" area, east end of Sled Track, Lancaster, Los Angeles County, CA

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

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.

Deaths among drivers and right-front passengers in frontal collisions: redesigned air bags relative to first-generation air bags.

PubMed

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

2008-03-01

After automakers were allowed the option of using sled tests for unbelted male dummies to certify the frontal crash performance of vehicles, most frontal air bags were depowered, starting in model year 1998, to reduce deaths and serious injuries arising from air bag deployments. Concern has been expressed that depowering air bags could compromise the protection of adult occupants. This study aimed to determine the effects of changes in air bag designs on risk of death among front-seat occupants. Deaths among drivers and right-front passengers per involvement in frontal police-reported crashes during calendar years 1998-2004 were compared among vehicles with sled-certified air bags (model years 1998-2004) and first-generation air bags (model years 1994-97). Frontal crash deaths were identified from the Fatality Analysis Reporting System. National estimates of police-reported crashes were derived from the National Automotive Sampling System/General Estimates System. Sled certification status for model years 1998-2004 was ascertained from published federal data and a survey of automobile manufacturers. Passenger cars, pickup trucks, sport utility vehicles, and minivans were studied. Stratified analyses were done to compute risk ratios (RR) and 95% confidence intervals (95% CI) for driver and right-front passenger deaths by air bag generation and crash, vehicle, and driver characteristics. In frontal crashes, overall RRs were 0.89 for driver deaths (95% CI = 0.74-1.08) and 0.89 for right-front passenger deaths (95% CI = 0.74-1.07) in sled-certified vehicles compared with first-generation air bag-equipped vehicles. Child right-front passengers (ages 0-4, 5-9) in vehicles with sled-certified air bags had statistically significant reductions in risk of dying in frontal collisions, including a 65% reduced risk among ages 0-4 (RR = 0.35; 95% CI = 0.21-0.60). No differences in effects of sled-certified air bags were observed between drivers ages 15-59 and 60-74 in sled

A system for measuring bottom profile, waves and currents in the high-energy nearshore environment

USGS Publications Warehouse

Sallenger, A.H.; Howard, P.C.; Fletcher, C. H.; Howd, P.A.

1983-01-01

A new data-acquisition system capable of measuring waves, currents and the nearshore profile in breaking waves as high as 5 m has been developed and successfully field-tested. Components of the mechanical system are a sled carrying a vertical mast, a double-drum winch placed landward of the beach, and a line that runs from one drum of the winch around three blocks, which are the corners of a right triangle, to the other drum of the winch. The sled is attached to the shore-normal side of the triangular line arrangement and is pulled offshore by one drum of the winch and onshore by the other. The profile is measured as the sled is towed along the shore-normal transect using an infrared rangefinder mounted landward of the winch and optical prisms mounted on top of the sled's mast. A pressure sensor and two-axis electromagnetic current meter are mounted on the frame of the sled. These data are encoded on the sled and telemetered to a receiving/recording station onshore. Preliminary results suggest that near-bottom offshore-flowing currents during periods of high-energy swell are important in forcing changes to the configuration of the nearshore profile. ?? 1983.

Greenland Inland Traverse (GrIT): 2010 Mobility Performance and Implications

DTIC Science & Technology

2011-10-01

solar irradiance were also measured. The right-hand bladder sled (Fig. 5), designated Sled2, had black- rubber covers ( EPDM roofing material) wrapped...CRREL TR-11-16 ix tion only). Sled2 had thin, black- rubber covers over the bladders to in- crease solar gain. Some performance improvement...Pole Station from McMurdo Station, a distance of 1030 miles, using large, rubber -track tractors to haul fuel and cargo over the snow on flexible

30 CFR 291.101 - What definitions apply to this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

... equipment, device, apparatus, or other object attached to a horizontal component or riser. Examples include...), pipeline end terminals (PLETs), anode sleds, other sleds, and jumpers (other than jumpers connecting subsea...

Thermal and Melt Wear Characterization of Materials in Sliding Contact at High Speed

DTIC Science & Technology

2014-03-01

wraparound slipper restrains the sled from flying off the rails as a result of aerodynamic lifting on the body . Figure 4 shows a representative VascoMax...in January 2008 to predict dynamic behavior of the rocket sled system during the actual test run. The left rear slipper from the third stage car...computational fluid dynamics model. Further, the slipper under consideration is the actual slipper of the third stage of the rocket sled, so the supersonic

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

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

5. INTERIOR, INSTRUMENTATION AND CONTROL BUILDING ADDITION. Looking north. ...

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

5. INTERIOR, INSTRUMENTATION AND CONTROL BUILDING ADDITION. Looking north. - Edwards Air Force Base, South Base Sled Track, Instrumentation & Control Building, South of Sled Track, Station "50" area, Lancaster, Los Angeles County, CA

4. NORTHWEST FRONT, WITH FOUR BULLET GLASS WINDOWS. Edwards ...

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

4. NORTHWEST FRONT, WITH FOUR BULLET GLASS WINDOWS. - Edwards Air Force Base, South Base Sled Track, Observation Block House, Station "O" area, east end of Sled Track, Lancaster, Los Angeles County, CA

6. SOUTH SIDE, DETAIL OF BULLET GLASS WINDOWS AT GROUND ...

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

6. SOUTH SIDE, DETAIL OF BULLET GLASS WINDOWS AT GROUND LEVEL. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

Team Sports

MedlinePlus

... sleds, which are affixed to two hockey skate blades under the seat. The sleds are about three ... encourages disabled people to participate in long-distance running. ATC provides support, training and technical expertise to ...

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

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. INTERIOR, ORIGINAL BLOCKHOUSE SECTION OF BUILDING 0512, NORTH WALL ...

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

6. INTERIOR, ORIGINAL BLOCKHOUSE SECTION OF BUILDING 0512, NORTH WALL FACING TEST TRACK. - Edwards Air Force Base, South Base Sled Track, Instrumentation & Control Building, South of Sled Track, Station "50" area, Lancaster, Los Angeles County, CA

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

36 CFR 13.1310 - Pets.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) The restrictions in this section do not apply to dogs when sufficient snow exists for skiing or dog sled use and the dogs are restrained as part of a sled dog team or for the purposes of skijoring. ...

7. CONTROL AND EQUIPMENT ROOM INTERIOR. Looking to southwest corner ...

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

7. CONTROL AND EQUIPMENT ROOM INTERIOR. Looking to southwest corner and entrance to cable tunnel. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

3. NORTHEAST SIDE, WITH A SINGLE BULLET GLASS WINDOW AND ...

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

3. NORTHEAST SIDE, WITH A SINGLE BULLET GLASS WINDOW AND SOUTHEAST REAR WITH ENTRY DOOR. - Edwards Air Force Base, South Base Sled Track, Observation Block House, Station "O" area, east end of Sled Track, Lancaster, Los Angeles County, CA

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

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

12. DETAIL, ENTRY STAIRWELL TO CABLE TUNNEL, LAUNCHING PAD IN ...

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

12. DETAIL, ENTRY STAIRWELL TO CABLE TUNNEL, LAUNCHING PAD IN THE LEFT DISTANCE, TRACKSIDE CAMERA STAND AT TOP CENTER. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fradkin, D.B.; Hull, L.M.; Laabs, G.W.

The results of dynamic sled track performance testing of advanced tandem configuration shaped-charge warheads against multiple-reactive-element tank armors are presented. Tandem configurations utilizing both currently fielded and experimental shaped-charge warheads were tested. Sled velocities used were between 400 and 1100 ft/s (Mach number 0.35 to 0.95), typical of the terminal approach velocity of TOW-type antitank missiles. High-speed motion pictures (5000 frames/s) of the sled in operation and a typical mock missile'' warhead package approaching the target are shown. Details of the sled design and fabrication and of the warhead package design and fabrication are presented. Sled track instrumentation is discussed.more » This instrumentation includes foil make/break switches and associated time interval meters (TIM) and digital delay units (DDU), magnetic Hall-effect transistors for measuring sled trajectory, and flash x-rays (FXR). Methods for timing the x-rays are presented. Schematic functional diagrams of the experimental setups are also given. Evidence of the ability to accurately time the delay between precursor and main warheads for even very long time delays are presented. FXR pictures illustrate the dynamics of the interaction of the jets with various target elements. The interaction dynamics of the jets is discussed in relation to the overall penetration performance of the tandem warhead. The use of x-ray fluorescence spectroscopy to help diagnose interaction dynamics is illustrated. The results of a test utilizing the missile propulsion rocket motor as a blast shield is presented in this paper. 2 refs., 22 figs.« less

1. STATION "50" AREA OVERVIEW, BUILDING 0512 AT FAR LEFT, ...

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

1. STATION "50" AREA OVERVIEW, BUILDING 0512 AT FAR LEFT, AND PADS FOR SHOP AND STORAGE BUILDINGS IN CENTER. Looking northeast. - Edwards Air Force Base, South Base Sled Track, Instrumentation & Control Building, South of Sled Track, Station "50" area, Lancaster, Los Angeles County, CA

A case for Redundant Arrays of Inexpensive Disks (RAID)

NASA Technical Reports Server (NTRS)

Patterson, David A.; Gibson, Garth; Katz, Randy H.

1988-01-01

Increasing performance of CPUs and memories will be squandered if not matched by a similar performance increase in I/O. While the capacity of Single Large Expensive Disks (SLED) has grown rapidly, the performance improvement of SLED has been modest. Redundant Arrays of Inexpensive Disks (RAID), based on the magnetic disk technology developed for personal computers, offers an attractive alternative to SLED, promising improvements of an order of magnitude in performance, reliability, power consumption, and scalability. This paper introduces five levels of RAIDs, giving their relative cost/performance, and compares RAID to an IBM 3380 and a Fujitsu Super Eagle.

TESTING HIGH-DIMENSIONAL COVARIANCE MATRICES, WITH APPLICATION TO DETECTING SCHIZOPHRENIA RISK GENES

PubMed Central

Zhu, Lingxue; Lei, Jing; Devlin, Bernie; Roeder, Kathryn

2017-01-01

Scientists routinely compare gene expression levels in cases versus controls in part to determine genes associated with a disease. Similarly, detecting case-control differences in co-expression among genes can be critical to understanding complex human diseases; however statistical methods have been limited by the high dimensional nature of this problem. In this paper, we construct a sparse-Leading-Eigenvalue-Driven (sLED) test for comparing two high-dimensional covariance matrices. By focusing on the spectrum of the differential matrix, sLED provides a novel perspective that accommodates what we assume to be common, namely sparse and weak signals in gene expression data, and it is closely related with Sparse Principal Component Analysis. We prove that sLED achieves full power asymptotically under mild assumptions, and simulation studies verify that it outperforms other existing procedures under many biologically plausible scenarios. Applying sLED to the largest gene-expression dataset obtained from post-mortem brain tissue from Schizophrenia patients and controls, we provide a novel list of genes implicated in Schizophrenia and reveal intriguing patterns in gene co-expression change for Schizophrenia subjects. We also illustrate that sLED can be generalized to compare other gene-gene “relationship” matrices that are of practical interest, such as the weighted adjacency matrices. PMID:29081874

TESTING HIGH-DIMENSIONAL COVARIANCE MATRICES, WITH APPLICATION TO DETECTING SCHIZOPHRENIA RISK GENES.

PubMed

Zhu, Lingxue; Lei, Jing; Devlin, Bernie; Roeder, Kathryn

2017-09-01

Scientists routinely compare gene expression levels in cases versus controls in part to determine genes associated with a disease. Similarly, detecting case-control differences in co-expression among genes can be critical to understanding complex human diseases; however statistical methods have been limited by the high dimensional nature of this problem. In this paper, we construct a sparse-Leading-Eigenvalue-Driven (sLED) test for comparing two high-dimensional covariance matrices. By focusing on the spectrum of the differential matrix, sLED provides a novel perspective that accommodates what we assume to be common, namely sparse and weak signals in gene expression data, and it is closely related with Sparse Principal Component Analysis. We prove that sLED achieves full power asymptotically under mild assumptions, and simulation studies verify that it outperforms other existing procedures under many biologically plausible scenarios. Applying sLED to the largest gene-expression dataset obtained from post-mortem brain tissue from Schizophrenia patients and controls, we provide a novel list of genes implicated in Schizophrenia and reveal intriguing patterns in gene co-expression change for Schizophrenia subjects. We also illustrate that sLED can be generalized to compare other gene-gene "relationship" matrices that are of practical interest, such as the weighted adjacency matrices.

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

11. ENTRY STAIRWELL TO CABLE TUNNEL. REMAINS OF ELECTRICAL DISTRIBUTION ...

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

11. ENTRY STAIRWELL TO CABLE TUNNEL. REMAINS OF ELECTRICAL DISTRIBUTION STATIONS AT LEFT, TRACKSIDE CAMERA STAND AT FAR RIGHT. Looking northeast toward launch pad. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

Relationships Between Knee Extension Moments During Weighted and Unweighted Gait and Strength Measures That Predict Knee Moments After ACL Reconstruction.

PubMed

Hartigan, Erin; Aucoin, Jennifer; Carlson, Rita; Klieber-Kusak, Melanie; Murray, Thomas; Shaw, Bernadette; Lawrence, Michael

Weighted gait increases internal knee extension moment impulses (KEMI) in the anterior cruciate ligament-reconstructed (ACLR) limb; however, limb differences persist. (1) KEMI during normal gait will influence KEMI during weighted gait and (2) peak knee extension (PKE) torque and time to reach PKE torque will predict KEMI during gait tasks. Descriptive laboratory study. Twenty-four women and 14 men completed 3 gait tasks (unweighted, vest, sled) and strength testing after discharge from rehabilitation and clearance to return to sports. KEMI were calculated during the first 25% of stance. PKE torque and time to reach PKE torque were obtained using a dynamometer. Data on the ACLR limb and symmetry indices (SIs) were analyzed for each sex. Women presented with asymmetrical PKE torques and KEMI across tasks. There were three correlations noted for KEMI: between the walk and vest, walk and sled, and vest and sled tasks. Slower time to PKE torque predicted limb asymmetries across tasks and KEMI in the ACLR limb during the sled task. Men presented with asymmetrical PKE torques and KEMI during the sled task. There was a correlation noted for KEMI between walk and vest tasks only. During the sled task, ACLR limb time to PKE torque predicted KEMI in the ACLR limb and PKE torque SI predicted KEMI SI. Women use asymmetrical KEMI profiles during all gait tasks, and those with worse KEMI during walking have worse KEMI during weighted gait. Men have asymmetrical KEMI when sled towing, and these KEMIs do not correlate with KEMI during walking or vest tasks. PKE torque deficits persist when attempting to return to sports. Only men use gains in PKE torque to improve KEMI profiles. Although quicker PKE torque generation will increase KEMI in women, normalization of KEMI profiles will not occur by increasing rate of force development only. Gait retraining is recommended to correct asymmetrical KEMI profiles used across gait tasks in women.

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

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.

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

Richtmyer-Meshkov instability experiments of miscible and immiscible incompressible fluids

NASA Astrophysics Data System (ADS)

Krivets, Vitaliy; Holt, Brason; Mokler, Matthew; Jacobs, Jeffrey

2017-11-01

Experiments were conducted in a 3 m tall vertical drop tower setup. A flat interface separating two liquids of differing density is formed in the Plexiglas tank with the heavier fluid in the bottom and the lighter one on top. Two liquids pairs were utilized, one - miscible (isopropyl alcohol and a calcium nitrate water mixture) and the other immiscible (silicone oil with the same heavy liquid), both with Atwood near 0.2. The tank is mounted on a rail mounted sled at 2 m initial height where an initial perturbation is generated using vertical periodic motion with 10 Hz frequency and 1 mm displacement, thus producing 3D interfacial waves. An impulsive acceleration, with approximately 100g magnitude, is imparted to the sled by a rail mounted weight released and allowed to fall, impacting the sled from above. Both weight and sled then travel freely down the rails where they are smoothly decelerated at the bottom of drop tower by magnetic brakes. PLIF is used to visualize mixing process by seeding fluorescein in the bottom fluid and illuminating using laser diode from above forming thin vertical sheet. The resulting fluorescent image sequences are captured using a digital camera mounted to the sled operating at a 100 Hz framing rate. Comparisons of the measured growth of the mixing zone for both immiscible and miscible liquid combinations with theoretical models are presented.

How have changes in air bag designs affected frontal crash mortality?

PubMed

Braver, Elisa R; Shardell, Michelle; Teoh, Eric R

2010-07-01

To determine whether front air bag changes have affected occupant protection, frontal crash mortality rates were compared among front outboard occupants in vehicles having certified-advanced air bags (latest generation of air bags) or sled-certified air bags with and without advanced features. Poisson marginal structural models were used to calculate standardized mortality rate ratios (MRRs) for front occupants per registered vehicle. Vehicle age-corrected mortality rates were lower for drivers of vehicles having sled-certified air bags with advanced features than for drivers having sled-certified air bags without advanced features (MRR = 0.88; 95% confidence interval [CI]: 0.81-0.95), including unbelted men and drivers younger than 60. The mortality rate was higher, though not statistically significant, for drivers having certified-advanced air bags compared with sled-certified air bags with advanced features (vehicle age-corrected MRR = 1.13; 95% CI: 0.97-1.32) and significantly higher for belted drivers (MRR = 1.21; 95% CI: 1.04-1.39). Advanced air bag features appeared protective for some occupants. However, increased mortality rates among belted drivers of vehicles having certified-advanced air bags relative to those having sled-certified air bags with advanced features suggest that further study is needed to identify any potential problems with requirements for certification. 2010 Elsevier Inc. All rights reserved.

23. "GAFFTC 20 APR 60, H65A F106A; ESCAPE SYSTEM RUN ...

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

23. "G-AFFTC 20 APR 60, H-6-5A F-106A; ESCAPE SYSTEM RUN 5A." Testing the ejection system on a Convair sled. - 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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Indriolo, Nick; Bergin, E. A.; Goicoechea, J. R.

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{sub u} ≤ 48. These CO SLEDs are compared to those reported in other galaxies, with the intention of empirically determining which mechanisms dominatemore » 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.« less

SMART Rotor Development and Wind Tunnel Test

DTIC Science & Technology

2009-09-01

amplifier and control system , and data acquisition, processing, and display systems . Boeing�s LRTS (Fig. 2), consists of a sled structure that...Support Test Stand Sled Tail Sting Outrigger Arm Figure 2: System integration test at whirl tower Port Rotor Balance Main Strut Flap Tail...demonstrated. Finally, the reliability of the flap actuation system was successfully proven in more than 60 hours of wind tunnel testing

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

Speckle Free, Low Coherency, High Brightness, and High Pulse Speed Infrared Collimated Light Sources for Mid-IR Target Designator and Hyperspectral Imaging

DTIC Science & Technology

2007-10-31

designator and hyperspectral imaging 6. AUfHOR(S) Yee-LoyLam 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION DenseLight...DenseLight Semiconductors CONTENTS 1. Introduction 3 1.1 Overview of Project 3 1.2 Organization of Project 4 1.3 Target...Performance 4 2. SLED Chip Design and Fabrication Development 5 2.1 Organization of Design Stages 5 2.2 SLED Chip Design 6 2.3

Babesia canis and other tick-borne infections in dogs in Central Poland.

PubMed

Welc-Faleciak, Renata; Rodo, Anna; Siński, Edward; Bajer, Anna

2009-12-23

Vector-borne infections constitute increasing health problem in dogs worldwide, including sled dogs, dramatically decreasing the fitness of working dogs and even leading to death. In the period 2006-2008 eighty-two blood samples were collected from eight sled dog kennels in Central Poland. The prevalence of four vector-borne infections (Babesia canis, Bartonella sp., Anaplasma/Ehrlichia and Borrelia burgdorferi) was estimated in 82 sled dogs using PCR and nested PCR for diagnosis and the same methods were used to identify the vector-borne pathogens in 26 dogs presenting at veterinary clinics with symptoms of vector-borne diseases. None of four studied vector-borne pathogens was detected in samples originating from veterinary clinics. Among the remaining 82 dogs B. canis infections were confirmed in three dogs undergoing treatment for babesiosis. The DNA of tick-borne pathogens was also found among 22 (27.8%) of the 79 apparently healthy dogs, including 20 cases of B. canis infection (25.3%), one case of B. burgdorferi s.l. infection and one case of Anaplasma phagocytophilum infection. No evidence of Bartonella spp. and Ehrlichia canis infections were found in this set of samples. Sequencing of a Babesia fragment of 18S rDNA amplified from acute (n=5) and asymptomatic (n=5) cases revealed that all isolates were identical to the Babesia canis canis sequence, originally isolated from Dermacentor reticulatus ticks in Poland. A range of factors was shown to affect the distribution of babesiosis in sled dogs. The data are also discussed in respect to the health risk factors generated by asymptomatic B. canis infections and the efficiency of chemoprophylaxis measures taken by sled dog owners.

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

STS-58 crewmembers participate in baseline data collection

NASA Image and Video Library

1993-09-29

S93-45365 (29 Sept 1993) --- Payload specialist Martin J. Fettman, in an oscillating sled device in upper left, participates in a data collection project for neurovestibular functions. His responses to the sled's movements are recorded by a team of monitors in the foreground. The seven Spacelab Life Sciences (SLS-2) crew members devoted a full day to miscellaneous biomedical data collection in preparation for next month's two week mission aboard Columbia.

Testing and Evaluation of the Bear Medical Systems, Inc. Bear 33 Volume Ventilator System

DTIC Science & Technology

1990-12-01

approved for publication. RICHARD J. KNECHT, Lt Col, USAF, NC ROGER L STORK , Col, USAF, BSC Project Scientist Chief, Crew Systems Branch EORCHENDER...no problems. After the vibration tests, a visual inspection of the humidifier revealed that a screw and metal clip from a terminal on the incoming...hexagonal J-bolt nuts, which secure the sled to the litter, with larger wing nuts. This modification will allow the sled to be adequately secured by

The broken escalator phenomenon. Aftereffect of walking onto a moving platform.

PubMed

Reynolds, R F; Bronstein, A M

2003-08-01

We investigated the physiological basis of the 'broken escalator phenomenon', namely the sensation that when walking onto an escalator which is stationary one experiences an odd sensation of imbalance, despite full awareness that the escalator is not going to move. The experimental moving surface was provided by a linear motor-powered sled, moving at 1.2 m/s. Sled velocity, trunk position, trunk angular velocity, EMG of the ankle flexors-extensors and foot-contact signals were recorded in 14 normal subjects. The experiments involved, initially, walking onto the stationary sled (condition Before). Then, subjects walked 20 times onto the moving sled (condition Moving), and it was noted that they increased their walking velocity from a baseline of 0.60 m/s to 0.90 m/s. After the moving trials, subjects were unequivocally warned that the platform would no longer move and asked to walk onto the stationary sled again (condition After). It was found that, despite this warning, subjects walked onto the stationary platform inappropriately fast (0.71 m/s), experienced a large overshoot of the trunk and displayed increased leg electromyographic (EMG) activity. Subjects were surprised by their own behaviour and subjectively reported that the 'broken escalator phenomenon', as experienced in urban life, felt similar to the experiment. By the second trial, most movement parameters had returned to baseline values. The findings represent a motor aftereffect of walking onto a moving platform that occurs despite full knowledge of the changing context. As such, it demonstrates dissociation between the declarative and procedural systems in the CNS. Since gait velocity was raised before foot-sled contact, the findings are at least partly explained by open-loop, predictive behaviour. A cautious strategy of limb stiffness was not responsible for the aftereffect, as revealed by no increase in muscle cocontraction. The observed aftereffect is unlike others previously reported in the

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

Molecular Gas Heating Mechanisms, and Star Formation Feedback in Merger/Starbursts: NGC 6240 and Arp 193 as Case Studies

NASA Astrophysics Data System (ADS)

Papadopoulos, Padelis P.; Zhang, Zhi-Yu; Xilouris, E. M.; Weiss, Axel; van der Werf, Paul; Israel, F. P.; Greve, T. R.; Isaak, Kate G.; Gao, Y.

2014-06-01

We used the SPIRE/FTS instrument aboard the Herschel Space Observatory to obtain the Spectral Line Energy Distributions (SLEDs) of CO from J = 4-3 to J = 13-12 of Arp 193 and NGC 6240, two classical merger/starbursts selected from our molecular line survey of local Luminous Infrared Galaxies (L IR >= 1011 L ⊙). The high-J CO SLEDs are then combined with ground-based low-J CO, 13CO, HCN, HCO+, CS line data and used to probe the thermal and dynamical states of their large molecular gas reservoirs. We find the two CO SLEDs strongly diverging from J = 4-3 onward, with NGC 6240 having a much higher CO line excitation than Arp 193, despite their similar low-J CO SLEDs and L FIR/L CO, 1 - 0, L HCN/L CO (J = 1-0) ratios (proxies of star formation efficiency and dense gas mass fraction). In Arp 193, one of the three most extreme starbursts in the local universe, the molecular SLEDs indicate a small amount (~5%-15%) of dense gas (n >= 104 cm-3) unlike NGC 6240 where most of the molecular gas (~60%-70%) is dense (n ~ (104-105) cm-3). Strong star-formation feedback can drive this disparity in their dense gas mass fractions, and also induce extreme thermal and dynamical states for the molecular gas. In NGC 6240, and to a lesser degree in Arp 193, we find large molecular gas masses whose thermal states cannot be maintained by FUV photons from Photon-Dominated Regions. We argue that this may happen often in metal-rich merger/starbursts, strongly altering the initial conditions of star formation. ALMA can now directly probe these conditions across cosmic epoch, and even probe their deeply dust-enshrouded outcome, the stellar initial mass function averaged over galactic evolution.

Molecular gas heating mechanisms, and star formation feedback in merger/starbursts: NGC 6240 and Arp 193 as case studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papadopoulos, Padelis P.; Zhang, Zhi-Yu; Xilouris, E. M.

2014-06-20

We used the SPIRE/FTS instrument aboard the Herschel Space Observatory to obtain the Spectral Line Energy Distributions (SLEDs) of CO from J = 4-3 to J = 13-12 of Arp 193 and NGC 6240, two classical merger/starbursts selected from our molecular line survey of local Luminous Infrared Galaxies (L {sub IR} ≥ 10{sup 11} L {sub ☉}). The high-J CO SLEDs are then combined with ground-based low-J CO, {sup 13}CO, HCN, HCO{sup +}, CS line data and used to probe the thermal and dynamical states of their large molecular gas reservoirs. We find the two CO SLEDs strongly diverging frommore » J = 4-3 onward, with NGC 6240 having a much higher CO line excitation than Arp 193, despite their similar low-J CO SLEDs and L {sub FIR}/L {sub CO,} {sub 1} {sub –0}, L {sub HCN}/L {sub CO} (J = 1-0) ratios (proxies of star formation efficiency and dense gas mass fraction). In Arp 193, one of the three most extreme starbursts in the local universe, the molecular SLEDs indicate a small amount (∼5%-15%) of dense gas (n ≥ 10{sup 4} cm{sup –3}) unlike NGC 6240 where most of the molecular gas (∼60%-70%) is dense (n ∼ (10{sup 4}-10{sup 5}) cm{sup –3}). Strong star-formation feedback can drive this disparity in their dense gas mass fractions, and also induce extreme thermal and dynamical states for the molecular gas. In NGC 6240, and to a lesser degree in Arp 193, we find large molecular gas masses whose thermal states cannot be maintained by FUV photons from Photon-Dominated Regions. We argue that this may happen often in metal-rich merger/starbursts, strongly altering the initial conditions of star formation. ALMA can now directly probe these conditions across cosmic epoch, and even probe their deeply dust-enshrouded outcome, the stellar initial mass function averaged over galactic evolution.« less

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.

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

Designing a warm-up protocol for elite bob-skeleton athletes.

PubMed

Cook, Christian; Holdcroft, Danny; Drawer, Scott; Kilduff, Liam P

2013-03-01

To investigate how different warm-ups influenced subsequent sled-pull sprint performance in Olympic-level bob-skeleton athletes as part of their preparation for the 2010 Winter Olympics. Three female and 3 male athletes performed 5 different randomized warm-ups of differing intensities, durations, and timing relative to subsequent testing, each 2 days apart, all repeated twice. After warm-ups, testing on a sled-pull sprint over 20 m, 3 repeats 3 min apart, took place. Performance testing showed improvement (P < .001, ES > 1.2) with both increasing intensity of warm-up and closeness of completion to testing, with 20-m sled sprinting being 0.1-0.25 s faster in higher-intensity protocols performed near testing In addition, supplementing the warm-ups by wearing of a light survival coat resulted in further performance improvement (P = .000, ES 1.8). Changing timing and intensity of warm-up and using an ancillary passive heat-retention device improved sprint performance in Olympic-level bob-skeleton athletes. Subsequent adoption of these on the competitive circuit was associated with a seasonal improvement in push times and was ultimately implemented in the 2010 Winter Olympics.

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.

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.

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.

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.

Verification of a ground-based method for simulating high-altitude, supersonic flight conditions

NASA Astrophysics Data System (ADS)

Zhou, Xuewen; Xu, Jian; Lv, Shuiyan

Ground-based methods for accurately representing high-altitude, high-speed flight conditions have been an important research topic in the aerospace field. Based on an analysis of the requirements for high-altitude supersonic flight tests, a ground-based test bed was designed combining Laval nozzle, which is often found in wind tunnels, with a rocket sled system. Sled tests were used to verify the performance of the test bed. The test results indicated that the test bed produced a uniform-flow field with a static pressure and density equivalent to atmospheric conditions at an altitude of 13-15km and at a flow velocity of approximately M 2.4. This test method has the advantages of accuracy, fewer experimental limitations, and reusability.

Modeling the Biodynamical Response of the Human Head for Injury Analysis

DTIC Science & Technology

2001-09-01

1 II. BACKGROUND ..............................................5 A. HUMAN ANATOMY ......................................5...facilitate the simulation of the sled acceleration test used for model validation. A. HUMAN ANATOMY 1. The Spine The muscles and other soft tissue

Comparing Driver Frontal Mortality in Vehicles with Redesigned and Older-Design Front Airbags

PubMed Central

Braver, Elisa R.; Kyrychenko, Sergey Y.; Ferguson, Susan A.

2004-01-01

In 1997, the National Highway Traffic Safety Administration amended its requirements for frontal crash performance under Federal Motor Vehicle Safety Standard 208 to temporarily allow 30 mph (48 kph) sled tests with unbelted dummies as an alternative to 30 mph head-on rigid-barrier vehicle tests. This change permitted automakers to reduce airbag inflation forces so that they would be less likely to injure occupants who are close to airbags when they first deploy. Most vehicle models were sled-certified starting in model year 1998. Airbag-related deaths have decreased since 1997; however, controversy persists about whether reduced inflation forces might be decreasing protection for some occupants in high-severity frontal crashes. To examine the effects of the regulatory changes, this study computed rate ratios (RR) and 95 percent confidence intervals (95% CI) for passenger vehicle driver deaths per vehicle registration during 2000–02 at principal impact points of 12 o’clock for 1998–99 model year vehicles relative to 1997 models. Passenger vehicles included in the study had both driver and passenger front airbags, had the same essential designs during the 1997–99 model years, and had been sled-certified for drivers throughout model years 1998 and 1999. An adjustment was made for the higher annual mileage of newer vehicles. Findings were that the effect of the regulatory change varied by vehicle type. For cars, sport utility vehicles, and minivans combined, there was an 11 percent decrease in fatality risk in frontal crashes after changing to sled certification (RR=0.89; 95% CI=0.82–0.96). Among pickups, however, estimated frontal fatality risk increased 35 percent (RR=1.35; 95% CI=1.12–1.62). For a broad range of frontal crashes (11, 12, and 1 o’clock combined), the results indicated a modest net benefit of the regulatory change across all vehicle types and driver characteristics. However, the contrary finding for pickups needs to be researched further

Comparing driver frontal mortality in vehicles with redesigned and older-design front airbags.

PubMed

Braver, Elisa R; Kyrychenko, Sergey Y; Ferguson, Susan A

2004-01-01

In 1997, the National Highway Traffic Safety Administration amended its requirements for frontal crash performance under Federal Motor Vehicle Safety Standard 208 to temporarily allow 30 mph (48 kph) sled tests with unbelted dummies as an alternative to 30 mph head-on rigid-barrier vehicle tests. This change permitted automakers to reduce airbag inflation forces so that they would be less likely to injure occupants who are close to airbags when they first deploy. Most vehicle models were sled-certified starting in model year 1998. Airbag-related deaths have decreased since 1997; however, controversy persists about whether reduced inflation forces might be decreasing protection for some occupants in high-severity frontal crashes. To examine the effects of the regulatory changes, this study computed rate ratios (RR) and 95 percent confidence intervals (95% CI) for passenger vehicle driver deaths per vehicle registration during 2000-02 at principal impact points of 12 o'clock for 1998-99 model year vehicles relative to 1997 models. Passenger vehicles included in the study had both driver and passenger front airbags, had the same essential designs during the 1997-99 model years, and had been sled-certified for drivers throughout model years 1998 and 1999. An adjustment was made for the higher annual mileage of newer vehicles. Findings were that the effect of the regulatory change varied by vehicle type. For cars, sport utility vehicles, and minivans combined, there was an 11 percent decrease in fatality risk in frontal crashes after changing to sled certification (RR=0.89; 95% CI=0.82-0.96). Among pickups, however, estimated frontal fatality risk increased 35 percent (RR=1.35; 95% CI=1.12-1.62). For a broad range of frontal crashes (11, 12, and 1 o'clock combined), the results indicated a modest net benefit of the regulatory change across all vehicle types and driver characteristics. However, the contrary finding for pickups needs to be researched further.

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.

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.

43 CFR 423.37 - Winter activities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... motor vehicle or snowmobile, except that you may tow sleds designed to be towed behind snowmobiles if... any appropriate means. (b) You must not ice skate, ice fish, or ice sail within 300 yards of dams...

43 CFR 423.37 - Winter activities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... motor vehicle or snowmobile, except that you may tow sleds designed to be towed behind snowmobiles if... any appropriate means. (b) You must not ice skate, ice fish, or ice sail within 300 yards of dams...

Rail passenger equipment collision tests : analysis of occupant protection measurements

DOT National Transportation Integrated Search

2000-01-01

The Federal Railroad Administration has been conducting research : on occupant protection in train collisions. As part of this research, : computer simulations have been performed, passenger seats have been sled tested, and two full-scale collision t...

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

Comparative Performance of Rear Facing Child Restraint Systems on the CMVSS 213 Bench and Vehicle Seats

PubMed Central

Tylko, Suzanne; Locey, Caitlin M.; Garcia-Espana, J. Felipe; Arbogast, Kristy B.; Maltese, Matthew R.

2013-01-01

The purpose of this study was to compare the dynamic response of rear-facing child restraint systems (RFCRS) installed on the CMVSS 213 sled bench and a selection of vehicle seats. Thirty-six sled tests were conducted: three models of rear facing CRS with an anthropomorphic test device (ATD) representing a 12 month old child (CRABI) were affixed via lower anchors (LATCH), 3 point belt without CRS base, and 3 point belt with CRS base to one of three vehicle seats or the CMVSS 213 bench seat. All CRS were subjected to an identical sled acceleration pulse. Two types of matched pair analysis: “bench-to-vehicle” and “method of attachment” were conducted. Statistically significant differences were observed in the kinematic responses of the ATD and the CRS. This is the first study to quantify differences between the regulatory bench and vehicle seats on a system level and evaluate the influence of attachment method. Our results show that the difference in RFCRS forward excursion between 3-point belt with base and LATCH installations was between 1 and 7 percent on the bench and 22 to 76 percent on the vehicle seats. When evaluating the dynamic performance of RFCRS, the use of real vehicle seats from vehicles that commonly carry children may provide valuable insight. The findings would require further confirmation using a broader selection of RFCRS and vehicle seats, before generalizable conclusions can be drawn. PMID:24406967

Locomotor adaptation is modulated by observing the actions of others

PubMed Central

Patel, Mitesh; Roberts, R. Edward; Riyaz, Mohammed U.; Ahmed, Maroof; Buckwell, David; Bunday, Karen; Ahmad, Hena; Kaski, Diego; Arshad, Qadeer

2015-01-01

Observing the motor actions of another person could facilitate compensatory motor behavior in the passive observer. Here we explored whether action observation alone can induce automatic locomotor adaptation in humans. To explore this possibility, we used the “broken escalator” paradigm. Conventionally this involves stepping upon a stationary sled after having previously experienced it actually moving (Moving trials). This history of motion produces a locomotor aftereffect when subsequently stepping onto a stationary sled. We found that viewing an actor perform the Moving trials was sufficient to generate a locomotor aftereffect in the observer, the size of which was significantly correlated with the size of the movement (postural sway) observed. Crucially, the effect is specific to watching the task being performed, as no motor adaptation occurs after simply viewing the sled move in isolation. These findings demonstrate that locomotor adaptation in humans can be driven purely by action observation, with the brain adapting motor plans in response to the size of the observed individual's motion. This mechanism may be mediated by a mirror neuron system that automatically adapts behavior to minimize movement errors and improve motor skills through social cues, although further neurophysiological studies are required to support this theory. These data suggest that merely observing the gait of another person in a challenging environment is sufficient to generate appropriate postural countermeasures, implying the existence of an automatic mechanism for adapting locomotor behavior. PMID:26156386

STS 61-A crewmembers in Spacelab D-1 science module

NASA Technical Reports Server (NTRS)

1985-01-01

West German payload specialist Ernst Messerschmid, foreground, opens a door on the materials science double rack (MSDR) to begin an experiment while Dutch payload specialist Wubbo J. Ockels performs a 'run' on the vestibular sled in the background.

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.

Effectiveness of restraint equipment in enclosed areas.

DOT National Transportation Integrated Search

1972-02-01

A series of 20-g decelerations of a crash sled was conducted to determine the magnitude of head impact decelerations while wearing various types of restraint equipment in small confined areas. Restraint webbing loads and head impact decelerations are...

Child restraint systems for civil aircraft.

DOT National Transportation Integrated Search

1978-03-01

Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

Children restraint systems for civil aircraft.

DOT National Transportation Integrated Search

1978-03-01

Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

Evaluation of devices to improve shoulder belt fit.

DOT National Transportation Integrated Search

1994-08-01

Dynamic HYGE sled tests were conducted to evaluate devices which are designed to reposition the : shoulder belt to provide for improved fit or comfort. Three different devices, representative of those : being marketed, were tested using the 3 and 6 y...

Influence of standing or seated pelvis on dummy responses in rear impacts.

PubMed

Viano, David C; Parenteau, Chantal S; Burnett, Roger

2012-03-01

There is a question whether the standing or seated pelvis should be used in Hybrid III dummy evaluations of seats and belt restraint systems in severe rear impacts. This study compares the standing and seated Hybrid III pelvis in matched rear sled tests. Sixteen sled tests were found at 10, 16 and 24 km/h rear delta V in Ford's archives where matched tests were run with the standing and seated pelvis in a belted Hybrid III dummy. Two new tests were conducted at 40 km/h rear delta V to extend the severity range. The head, chest and pelvis were instrumented with triaxial accelerometers and the upper and lower neck, thoracic spine and lumbar spine had transducers measuring triaxial loads and moments. Belt Loads were measured. High-speed video recorded different views of the dummy motion. Dummy kinematics and biomechanical responses were compared for all of the data with the two different Hybrid III pelvic designs. In the 40 km/h sled tests, the dummy motion and excursion were essentially similar with the standing and seated pelvis. The similarities included the lap belt interaction with the pelvis and the leg movement upward flexing the hip joint. Overall, similar biomechanic and kinematic responses were found, including the pelvic acceleration, spinal forces and moments. For the lower speed tests at 10, 16 and 24 km/h, the motion sequence was also similar with the two different pelvises, including the upward movement of the legs as the seat was loaded and rebound kinematics. The biomechanical responses were similar. The seated pelvis involves only a small portion of the upper leg molded into the vinyl skin of the pelvis and does not limit leg rotation at the hip joint. Furthermore, lap belt loads were minimal during the rearward movement of the dummy. The matched testing showed no significant difference in occupant kinematics or biomechanical responses between the standing and seated pelvis in rear sled tests. The Hybrid III dummy with the seated pelvis is suitable

An overview of frontal air bag performance with changes in frontal crash-test requirements: findings of the Blue Ribbon Panel for the evaluation of advanced technology air bags.

PubMed

Ferguson, Susan A; Schneider, Lawrence W

2008-10-01

In the mid-1990s, evidence emerged that air bag deployments could result in deaths to vulnerable vehicle occupants who were very close to air bag modules when they deployed. In 1997, federal frontal crash test requirements were modified to allow crash testing with unbelted dummies to be performed using sled tests. As a result, vehicle manufacturers were able to redesign air bags to deploy with less force and energy, thereby reducing the toll of air bag-induced deaths. However, there was concern that depowered air bags may not provide the same level of protection to unbelted occupants in severe frontal crashes, particularly occupants of large stature and body mass. This paper provides a summary of recent studies addressing this issue. To expedite the accrual of data regarding air bag performance, the collection of additional crash data was funded by the Alliance of Automobile Manufacturers. A panel of experts was commissioned to oversee the process and evaluate the data. During the past 6 years, a series of studies has been undertaken by panel members and others to evaluate the performance of redesigned air bags and the data are summarized here. There is now convincing evidence that the combination of air bag redesign and public education have resulted in dramatic reductions in air bag-induced infant and child deaths. In addition, the frontal crash fatality risks among children sitting in front seats have been reduced by as much as half, with younger children showing the greatest benefits. Among adult drivers and right-front passengers, there is no evidence for the predicted overall loss of protection with sled-certified air bags and there are far fewer air bag-induced deaths among this population. However, despite exhaustive analyses of frontal-crash data, the possibility of a somewhat elevated fatality risk among a subset of unbelted drivers in sled-certified 1998-1999 model vehicles cannot be ruled out. There also is some evidence that the risks of serious chest

Connecting, Protecting, and Informing the Next Generation of First Responders

DTIC Science & Technology

2015-12-10

SLED is the Bluetooth Indoor Proximity System (BLIPS) that uses beacons to track first responders’ progress through indoor spaces. As first...Outfitting BLIPS with Bluetooth and Wi-Fi capability became a learning experience for two co- operative education students from Rensselaer Polytechnic

The Efficacy of Wrestling-Style Compression Suits to Improve Maximum Isometric Force and Movement Velocity in Well-Trained Male Rugby Athletes.

PubMed

McMaster, Daniel T; Beaven, Christopher M; Mayo, Brad; Gill, Nicholas; Hébert-Losier, Kim

2017-01-01

Purpose: The prevalence of compression garment (CG) use is increasing with athletes striving to take advantage of the purported benefits to recovery and performance. Here, we investigated the effect of CG on muscle force and movement velocity performance in athletes. Methods: Ten well-trained male rugby athletes wore a wrestling-style CG suit applying 13-31 mmHg of compressive pressure during a training circuit in a repeated-measures crossover design. Force and velocity data were collected during a 5-s isometric mid-thigh pull (IMTP) and repeated countermovement jump (CMJ), respectively; and time to complete a 5-m horizontal loaded sled push was also measured. Results: IMTP peak force was enhanced in the CG condition by 139 ± 142 N (effect size [ES] = 0.36). Differences in CMJ peak velocity (ES = 0.08) and loaded sled-push sprint time between the conditions were trivial (ES = -0.01). A qualitative assessment of the effects of CG wear suggested that the likelihood of harm was unlikely in the CMJ and sled push, while a beneficial effect in the CMJ was possible, but not likely. Half of the athletes perceived a functional benefit in the IMTP and CMJ exercises. Conclusion: Consistent with other literature, there was no substantial effect of wearing a CG suit on CMJ and sprint performance. The improvement in peak force generation capability in an IMTP may be of benefit to rugby athletes involved in scrummaging or lineout lifting. The mechanism behind the improved force transmission is unclear, but may involve alterations in neuromuscular recruitment and proprioceptive feedback.

Superluminescent light emitting diodes: the best out of two worlds

NASA Astrophysics Data System (ADS)

Rossetti, M.; Napierala, J.; Matuschek, N.; Achatz, U.; Duelk, M.; Vélez, C.; Castiglia, A.; Grandjean, N.; Dorsaz, J.; Feltin, E.

2012-03-01

Since pico-projectors were starting to become the next electronic "must-have" gadget, the experts were discussing which light-source technology seems to be the best for the existing three major projection approaches for the optical scanning module such as digital light processing, liquid crystal on silica and laser beam steering. Both so-far used light source technologies have distinct advantages and disadvantages. Though laser-based pico-projectors are focus-free and deliver a wider color gamut, their major disadvantages are speckle noise, cost and safety issues. In contrast, projectors based on cheaper Light Emitting Diodes (LEDs) as light source are criticized for a lack of brightness and for having limited focus. Superluminescent Light Emitting Diodes (SLEDs) are temporally incoherent and spatially coherent light sources merging in one technology the advantages of both Laser Diodes (LDs) and LEDs. With almost no visible speckle noise, focus-free operation and potentially the same color gamut than LDs, SLEDs could potentially answer the question which light source to use in future projector applications. In this quest for the best light source, we realized visible SLEDs emitting both in the red and blue spectral region. While the technology required for the realization of red emitters is already well established, III-nitride compounds required for blue emission have experienced a major development only in relatively recent times and the technology is still under development. The present paper is a review of the status of development reached for the blue superluminescent diodes based on the GaN material system.

Effect of realistic vehicle seats, cushion length, and lap belt geometry on child ATD kinematics.

DOT National Transportation Integrated Search

2011-12-01

This series of sled tests examined the effect of using real vehicle seats on child ATD performance. Cushion length was varied from production length of 450 mm to a shorter length of 350 mm. Lap belt geometry was set to rear, mid, and forward anchorag...

Optimizing protection for rear seat occupants : assessing booster performance with realistic belt geometry using the hybrid III 6YO ATD.

DOT National Transportation Integrated Search

2011-11-01

A series of sled tests was conducted to examine the performance of booster seats under belt geometries representing the range found in the rear seats of current vehicles. Twelve tests were performed with the standard 6YO Hybrid III ATD and 29 tests w...

Pilot Studies on Object Motion Perception During Linear Self-Motion After Long Duration Centrifugation of Human Subjects

DTIC Science & Technology

1993-02-01

Taylor & Creelman , 1967.) Measurements were taken with the sled moving either in forward or backward direction, each threshold being measured once...Furrer, R. & Messerschmid, E. (1990). Space Sickness on Earth. Experimental Brain Research 79(3), 661-663. Taylor, M.M. & Creelman . C.D. (1967). PEST

36 CFR 1002.19 - Winter activities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Winter activities. 1002.19 Section 1002.19 Parks, Forests, and Public Property PRESIDIO TRUST RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing...

Influence of near-bottom environmental conditions on the structure of bathyal macrobenthic crustacean assemblages from the Capbreton canyon (Bay of Biscay, NE Atlantic)

NASA Astrophysics Data System (ADS)

Marquiegui, Mikel A.; Sorbe, Jean Claude

1999-07-01

Sled and box-corer samplings were performed at two sites in the Capbreton canyon in order to appreciate the influence of near-bottom environmental conditions on the structure of their macrobenthic communities (crustaceans). Although located at similar depths (ca. 1 000 m), these two sites were characterised by different physicochemical conditions at the sediment-water interface, probably related with the morphology of the submarine valley (reduced environment, oxygen depletion and stagnation of bottom water at site A; normal oceanic conditions on the near-bottom environment of site B). The analysis of the collected fauna revealed a low similarity between the two sites, mainly due to the unusual dominance of three epibenthic species in sled samples from site A: the amphipod Bonnierella abyssorum, the tanaid Apseudes spinosus and the isopod Arcturopsis giardi. Due to their apparent rarity or absence in adjacent non-canyon communities, such epibenthic crustaceans may be considered as `canyon indicator species' able to exhibit abundant populations within the peculiar confinement area of this canyon.

Optical Fiber Demodulation System with High Performance for Assessing Fretting Damage of Steam Generator Tubes

PubMed Central

Huang, Peijian; Wang, Ning; Li, Junying; Zhu, Yong; Zhang, Jie; Xi, Zhide

2018-01-01

In order to access the fretting damage of the steam generator tube (SGT), a fast fiber Fabry-Perot (F-P) non-scanning correlation demodulation system based on a super luminescent light emitting diode (SLED) was performed. By demodulating the light signal coming out from the F-P force sensor, the radial collision force between the SGT and the tube support plate (TSP) was interrogated. For higher demodulation accuracy, the effects of the center wavelength, bandwidth, and spectrum noise of SLED were discussed in detail. Specially, a piezoelectric ceramic transducer (PZT) modulation method was developed to get rid of the interference of mode coupling induced by different types of fiber optics in the demodulation system. The reflectivity of optical wedge and F-P sensor was optimized. Finally, the demodulation system worked well in a 1:1 steam generator test loop and successfully demodulated a force signal of 32 N with a collision time of 2 ms. PMID:29329225

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.

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. (c) 2009 IPEM. Published by Elsevier Ltd. All rights reserved.

Optical Fiber Demodulation System with High Performance for Assessing Fretting Damage of Steam Generator Tubes.

PubMed

Huang, Peijian; Wang, Ning; Li, Junying; Zhu, Yong; Zhang, Jie; Xi, Zhide

2018-01-12

In order to access the fretting damage of the steam generator tube (SGT), a fast fiber Fabry-Perot (F-P) non-scanning correlation demodulation system based on a super luminescent light emitting diode (SLED) was performed. By demodulating the light signal coming out from the F-P force sensor, the radial collision force between the SGT and the tube support plate (TSP) was interrogated. For higher demodulation accuracy, the effects of the center wavelength, bandwidth, and spectrum noise of SLED were discussed in detail. Specially, a piezoelectric ceramic transducer (PZT) modulation method was developed to get rid of the interference of mode coupling induced by different types of fiber optics in the demodulation system. The reflectivity of optical wedge and F-P sensor was optimized. Finally, the demodulation system worked well in a 1:1 steam generator test loop and successfully demodulated a force signal of 32 N with a collision time of 2 ms.

Modeling of Underwater Bomb Trajectory for Mine Clearance

DTIC Science & Technology

2010-01-01

suitable for a shallow water operation. The mine counter- measure airplane (AMCM) can tow the very capable sled (with the MK-103 through MK- 106 ...explosive in the live weapon is PBXN -109, whereas the inert weapons have filling to maintain appropriate weight and balance. Figure 6. Artificial

Biomechanical and injury response to posterolateral loading from torso side airbags.

PubMed

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

2010-11-01

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 x 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°.

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.

CO excitation in the Seyfert galaxy NGC 34: stars, shock or AGN driven?

NASA Astrophysics Data System (ADS)

Mingozzi, M.; Vallini, L.; Pozzi, F.; Vignali, C.; Mignano, A.; Gruppioni, C.; Talia, M.; Cimatti, A.; Cresci, G.; Massardi, M.

2018-03-01

We present a detailed analysis of the X-ray and molecular gas emission in the nearby galaxy NGC 34, to constrain the properties of molecular gas, and assess whether, and to what extent, the radiation produced by the accretion on to the central black hole affects the CO line emission. We analyse the CO spectral line energy distribution (SLED) as resulting mainly from Herschel and ALMA data, along with X-ray data from NuSTAR and XMM-Newton. The X-ray data analysis suggests the presence of a heavily obscured active galactic nucleus (AGN) with an intrinsic luminosity of L1-100 keV ≃ 4.0 × 1042 erg s-1. ALMA high-resolution data (θ ≃ 0.2 arcsec) allow us to scan the nuclear region down to a spatial scale of ≈100 pc for the CO(6-5) transition. We model the observed SLED using photodissociation region (PDR), X-ray-dominated region (XDR), and shock models, finding that a combination of a PDR and an XDR provides the best fit to the observations. The PDR component, characterized by gas density log(n/cm-3) = 2.5 and temperature T = 30 K, reproduces the low-J CO line luminosities. The XDR is instead characterized by a denser and warmer gas (log(n/cm-3) = 4.5, T = 65 K), and is necessary to fit the high-J transitions. The addition of a third component to account for the presence of shocks has been also tested but does not improve the fit of the CO SLED. We conclude that the AGN contribution is significant in heating the molecular gas in NGC 34.

76 FR 53102 - Federal Motor Vehicle Safety Standards; Denial of Petition for Rulemaking; School Buses

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-25

... chronological order): Studies NTSB, 1987 In 1987, the NTSB reported on its investigation of forty-three post... seat belts by using the sled test data obtained from NHTSA's 2002 school bus safety study. For... incorporate test procedures to test lap/shoulder belts in small school buses and voluntarily-installed lap...

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;…

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…

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…

Payload specialist Martin Fettmen during data collection neurovestibular test

NASA Image and Video Library

1993-09-29

S93-45314 (29 Sept 1993) --- Payload specialist Martin J. Fettman, in an oscillating sled device, participates in a data collection project for neurovestibular functions. The seven Spacelab Life Sciences (SLS-2) crewmembers devoted a full day to miscellaneous biomedical data collection in preparation for next month's two week mission aboard Columbia.

77 FR 33998 - Make Inoperative Exemptions; Retrofit On-Off Switches for Air Bags

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... children, in relatively low speed crashes. It was shown that the majority of these fatalities occurred... children in the rear; amending FMVSS No. 208 to allow for a limited time a sled test option for expediting... child to be placed in the front passenger seat for monitoring purposes. (The Ronald Reagan Institute of...

STS-58 crewmembers participate in baseline data collection

NASA Image and Video Library

1993-09-29

S93-45363 (29 Sept 1993) --- Payload specialist Martin J. Fettman, in an oscillating sled device, participates in a data collection project for neurovestibular functions. The seven Spacelab Life Sciences (SLS-2) crewmembers devoted a full day to miscellaneous biomedical data collection in preparation for next month's two week mission aboard Columbia.

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.

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

HERUS: A CO ATLAS FROM SPIRE SPECTROSCOPY OF LOCAL ULIRGs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pearson, Chris; Rigopoulou, Dimitra; Hurley, Peter

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 μmore » m, with photometry in the SPIRE bands at 250, 350, and 500 μ m. The spectra include near complete CO ladders for over half of our sample, as well as fine structure lines from [C i] 370 μ m, [C i] 609 μ m, and [N ii] 205 μ m. We also detect H{sub 2}O 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.« less

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.

Tail Separation and Surface Impact Effects on the Underwater Trajectory of the JDAM

DTIC Science & Technology

2010-05-01

tow the very capable sled (with the MK-103 through MK- 106 installed) into shallow water, but is unable to work in low visibility or at night. The...delay depends on which types of targets the weapon is to attack. The explosive in the live weapon is PBXN -109, whereas the inert weapons have

Premature ignition of a rocket motor.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Darlene Ruth

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.

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…

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.

Effects of a Negative G Strap on Restraint Dynamics and Human Impact Response.

DTIC Science & Technology

1983-12-01

When Dat .Entered) REPORT DOCUMENTATION PAGE READ INSTRUCTIONS " BEFORE COMPLETING FORM - I. REPORT NUMBER 12. GOVT ACCESSION NO. 3. RECIPIENT’S...SMOOTHED) 0.,7 460 -9.56 S62Taxis 0.47 SS7 -0.31 5602 AXIS 2.22 477 -0.11 3S3 SLED VELOCITY (FT/SEC) INTEGRATED ACCELERATION 0.02 288 -30.04

Design and Test Criteria for Increased Energy-Absorbing Seat Effectiveness

DTIC Science & Technology

1983-03-01

condition . ........ 35 8 CAMI aled. . . . . . . . . . . 37 9 CAMI wire - bending decelerator mechanism.... 38 10 Typical baseline deceleration pulses for...8217. * A * (b) Sled and wires following test. "Fiigure 9. CAI wire - bending decelerator mechanism. 38 OF --. 9 O 9 ’ W W v v v v W ’W A𔃾 50 so- 40- 40

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

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.

Low-Temperature Flex Durability of Fabrics for Polar Sleds

DTIC Science & Technology

2014-10-06

friction owing to solar gain, so SPoT is systematically replacing older tan bladders with black ones constructed from similar polyurethane -coated...specimens of the existing bladder material (single-layer polyurethane - coated fabric) within a few cycles. Remarkably, the specimens could with- stand...fabrics: • Antarctic traverses should continue to use fuel bladders constructed from ATL-853C (black) polyurethane -coated fabric as supplied by Aero Tec

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.

The influence of personal protection equipment, occupant body size, and restraint system on the frontal impact responses of Hybrid III ATDs in tactical vehicles.

PubMed

Zaseck, Lauren Wood; Orton, Nichole Ritchie; Gruber, Rebekah; Rupp, Jonathan; Scherer, Risa; Reed, Matthew; Hu, Jingwen

2017-08-18

Although advanced restraint systems, such as seat belt pretensioners and load limiters, can provide improved occupant protection in crashes, such technologies are currently not utilized in military vehicles. The design and use of military vehicles presents unique challenges to occupant safety-including differences in compartment geometry and occupant clothing and gear-that make direct application of optimal civilian restraint systems to military vehicles inappropriate. For military vehicle environments, finite element (FE) modeling can be used to assess various configurations of restraint systems and determine the optimal configuration that minimizes injury risk to the occupant. The models must, however, be validated against physical tests before implementation. The objective of this study was therefore to provide the data necessary for FE model validation by conducting sled tests using anthropomorphic test devices (ATDs). A secondary objective of this test series was to examine the influence of occupant body size (5th percentile female, 50th percentile male, and 95th percentile male), military gear (helmet/vest/tactical assault panels), seat belt type (3-point and 5-point), and advanced seat belt technologies (pretensioner and load limiter) on occupant kinematics and injury risk in frontal crashes. In total, 20 frontal sled tests were conducted using a custom sled buck that was reconfigurable to represent both the driver and passenger compartments of a light tactical military vehicle. Tests were performed at a delta-V of 30 mph and a peak acceleration of 25 g. The sled tests used the Hybrid III 5th percentile female, 50th percentile male, and 95th percentile male ATDs outfitted with standard combat boots and advanced combat helmets. In some tests, the ATDs were outfitted with additional military gear, which included an improved outer tactical vest (IOTV), IOTV and squad automatic weapon (SAW) gunner with a tactical assault panel (TAP), or IOTV and rifleman with

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…

Brain Management During Trauma

NASA Astrophysics Data System (ADS)

Shatsky, Stanley A.

1984-01-01

The Neurosurgeon faces a dilemma, that is, how to treat and reconstruct the injured skull and brain with limited knowledge as to how the injury occurred. In an attempt to understand such injuries, our group assembled a series of acceleration sleds to experimentally reproduce these injuries in primates and high frame rate flash x-ray cine system to radiographically study their time course.

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

...Notice is hereby given that the U.S. International Trade Commission has determined not to review the presiding administrative law judge's (``ALJ'') initial determination (``ID'') (Order No. 15) granting-in-part the motion of complainants Samsung LED Co., Ltd. of Suwon City, South Korea and Samsung LED America, Inc. of Atlanta, Georgia (collectively ``SLED'') to amend the Complaint and Notice of Investigation (NOI).

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

The Use of Various Failure Criteria as Applied to High Speed Wear

DTIC Science & Technology

2011-12-01

This research has been aimed at developing methods to predict mechanical wear of sliding bodies at high velocities. Specifically, wear of test sled...Several failure criteria were evaluated as possible methods to estimate damaged material from the sliding body . The Johnson and Cook constitutive...Data [11] . . . . . . . . . . . . . 12 1.11. Finite Element Model Used by Burton [11] . . . . . . . . . . . 12 1.12. HHSTT Third Stage Velocity

ER Consolidated Qtrly Rpt_July-September 2015_January 2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

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).more » 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.« less

100 GeV SLAC Linac

NASA Astrophysics Data System (ADS)

Farkas, Z. D.

2002-03-01

The SLAC beam energy can be increased from the current 50 GeV to 100 GeV, if we change the operating frequency from the present 2856 MHz to 11424 MHz, using technology developed for the NLC. We replace the power distribution system with a proposed NLC distribution system as shown in Fig. 1. The four 3 meter s-band 820 nS .ll time accelerator sections are replaced by six 2 meter x-band 120 nS .ll time sections. Thus the accelerator length per klystron retains the same length, 12 meters. The 4050 65MW- 3.5microS klystrons are replaced by 75MW-1.5microS permanent magnet klystrons developed here and in Japan. The present input to the klystrons would be multiplied by a factor of 4 and possibly ampli.ed. The SLED cavities have to be replaced. The increase in beam voltage is due to the higher elastance to group velocity ratio, higher compression ratio and higher unloaded to external Q ratio of the new SLED cavities. The average power input is reduced because of the narrower klystron pulse width and because the klystron electro-magnets are replaced by permanent magnets.

Comparison of car seats in low speed rear-end impacts using the BioRID dummy and the new neck injury criterion (NIC).

PubMed

Boström, O; Fredriksson, R; Håland, Y; Jakobsson, L; Krafft, M; Lövsund, P; Muser, M H; Svensson, M Y

2000-03-01

Long-term whiplash associated disorders (WAD) 1-3 sustained in low velocity rear-end impacts is the most common disability injury in Sweden. Therefore, to determine neck injury mechanisms and develop methods to measure neck-injury related parameters are of importance for current crash-safety research. A new neck injury criterion (NIC) has previously been proposed and evaluated by means of dummy, human and mathematical rear-impact simulations. So far, the criterion appears to be sensitive to the major car and collision related risk factors for injuries with long-term consequences. To further evaluate the applicability of NIC, four seats were tested according to a recently proposed sled-test procedure. 'Good' as well as 'bad' seats were chosen on the basis of a recently presented disability risk ranking list. The dummy used in the current tests was the Biofidelic Rear Impact Dummy (BioRID). The results of this study showed that NICmax values were generally related to the real-world risk of long-term WAD 1-3. Furthermore, these results suggested that NICmax calculated from sled tests using the BioRID dummy can be used for evaluating the neck injury risk of different car seats.

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.

Naval Biodynamics Laboratory 1993 Command History

DTIC Science & Technology

1993-01-01

position and alignment, camera optical calibration, photo target position, and standard anatomical coordinate systems based upon X-rays of each HRV...safety range. Before, during, and after each sled run, a physiological data acquisition system is used to collect and analyze physiological measurements ...experimental devices. It is also responsible for the configuring of field data measuring and acquisition systems for use aboard ships or at other field

EERE's State & Local Energy Data Tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

EERE's State & Local Energy Data Tool

ScienceCinema

Shambarger, Erick; DeCesaro, Jennifer

2018-05-30

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.

Aircraft Crash Survival Design Guide. Volume 4. Aircraft Seats, Restraints, Litters, and Cockpit/Cabin Delethalization

DTIC Science & Technology

1989-12-01

ILLUSTRATIONS (CONTD) 44 Tubular strut wire - bending energy absorber ...... ........... 91 45 Inversion tube concepL with typical force-deformation...expected from a rod-bending sled decelerator and a wire - bending seat load limiter (Refer- ences 35 and 36). Therefore, correcting the calculated...attaching the seat bucket to the rollers, compressive as well as tensile loads can be sustained. Two variations of the wire - bending device have been

Handheld Broadband Electromagnetic UXO Sensor

DTIC Science & Technology

2006-12-01

metal pipes of various sizes, some ferrous (steel) and some nonferrous (3 aluminum, 2 copper), have been buried at depths ranging from 10 to 110cm...Cart- or Sled-Mounted, and Pushed or Towed ......4 Figure 4. Example of Metallic Target Spectra for Sensor Axis...1 1.0 EXECUTIVE SUMMARY 1.1 BACKGROUND Detection of unexploded ordnance (UXO) and discrimination between UXO and metallic clutter pose challenges

Project Development Model | Integrated Energy Solutions | NREL

Science.gov Websites

. The five elements of project fundamentals are: Baseline: Analyze the current situation for the site . The two-phase iterative model includes elements in project fundamentals and project development based State and Local Energy Data (SLED) tool, developed by NREL for the U.S. Department of Energy, to get

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

DTIC Science & Technology

2007-09-01

include a machine shop, a welding shop, carpenter and wood shop, metal heat treatment shop, bead blast shop, paint shop, non-destructive inspection...annually. In 2005, 227 motors were fired. Sled operation can involve activities such as carrying explosives, testing ejection seats, shooting lasers ...Cinetheodolite-type metric cameras and/or laser tracking equipment are used for aircraft flight trajectories exceeding 500 feet above ground level

Denton, Texas: Using Transportation Data to Reduce Fuel Consumption (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

This fact sheet "Denton, Texas: Using Transportation Data to Reduce Fuel Consumption" explains how the City of Denton used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

The acute potentiating effects of back squats on athlete performance.

PubMed

Crewther, Blair T; Kilduff, Liam P; Cook, Christian J; Middleton, Matt K; Bunce, Paul J; Yang, Guang-Zhong

2011-12-01

Crewther, BT, Kilduff, LP, Cook, CJ, Middleton, MK, Bunce, PJ, and Yang, G-Z. The acute potentiating effects of back squats on athlete performance. J Strength Cond Res 25(12): 3319-3325, 2011-This study examined the acute potentiating effects of back squats on athlete performance with a specific focus on movement specificity and the individual timing of potentiation. Nine subelite male rugby players performed 3 protocols on separate occasions using a randomized, crossover, and counterbalanced design. Each protocol consisted of performance testing before a single set of 3 repetition maximum (3RM) back squats, followed by retesting at ∼15 seconds, 4, 8, 12, and 16 minutes. The 3 tests were countermovement jumps (CMJs), sprint performance (5 and 10 m), and 3-m horizontal sled pushes with a 100-kg load. Relationships between the individual changes in salivary testosterone and cortisol concentrations and performance were also examined. The 3RM squats significantly (p < 0.001) improved CMJ height at 4 (3.9 ± 1.9%), 8 (3.5 ± 1.5%), and 12 (3.0 ± 1.4%) minutes compared with baseline values, but no temporal changes in sprinting and sled times were identified. On an individual level, the peak relative changes in CMJ height (6.4 ± 2.1%, p < 0.001) were greater than the 3-m sled (1.4 ± 0.6%), 5-m (2.6 ± 1.0%), and 10-m sprint tests (1.8 ± 1.0%). In conclusion, a single set of 3RM squats was found effective in acutely enhancing CMJ height in the study population, especially when the recovery period was individualized for each athlete. The study results also suggest that the potentiating effects of squats may exhibit some degree of movement specificity, being greater for those exercises with similar movement patterns. The current findings have practical implications for prescribing warm-up exercises, individualizing training programs, and for interpreting postactivation potentiation research.

Heparin free dialysis in critically sick children using sustained low efficiency dialysis (SLEDD-f): A new hybrid therapy for dialysis in developing world

PubMed Central

Khare, Anshika; Dhaliwal, Maninder; Raghunathan, Veena; Wadhwani, Nikita; Nandwani, Ashish; Yadav, Dinesh Kumar; Mahapatra, Amit Kumar; Raina, Rupesh

2018-01-01

Background In critically sick adults, sustained low efficiency dialysis [SLED] appears to be better tolerated hemodynamically and outcomes seem to be comparable to CRRT. However, there is paucity of data in critically sick children. In children, two recent studies from Taiwan (n = 11) and India (n = 68) showed benefits of SLED in critically sick children. Aims and objectives The objective of the study was to look at the feasibility and tolerability of sustained low efficiency daily dialysis-filtration [SLEDD-f] in critically sick pediatric patients. Material and methods Design: Retrospective study Inclusion criteria: All pediatric patients who had undergone heparin free SLEDD-f from January 2012 to October 2017. Measurements: Data collected included demographic details, vital signs, PRISM III at admission, ventilator parameters (where applicable), number of inotropes, blood gas and electrolytes before, during, and on conclusion of SLED therapy. Technical information was gathered regarding SLEDD-f prescription and complications. Results Between 2012–2017, a total of 242 sessions of SLEDD-f were performed on 70 patients, out of which 40 children survived. The median age of patients in years was 12 (range 0.8–17 years), and the median weight was 39 kg (range 8.5–66 kg). The mean PRISM score at admission was 8.77±7.22. SLEDD-f sessions were well tolerated, with marked improvement in fluid status and acidosis. Premature terminations had to be done in 23 (9.5%) of the sessions. There were 21 sessions (8.6%) terminated due to hypotension and 2 sessions (0.8%) terminated due to circuit clotting. Post- SLEDD-f hypocalcemia occurred in 15 sessions (6.2%), post- SLEDD-f hypophosphatemia occurred in 1 session (0.4%), and post- SLEDD-f hypokalemia occurred in 17 sessions (7.0%). Conclusions This study is the largest compiled data on pediatric SLEDD-f use in critically ill patients. Our study confirms the feasibility of heparin free SLEDD-f in a larger pediatric

Moab, Utah: Using Energy Data to Target Carbon Reductions from Building Energy Efficiency (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strategic Priorities and Impact Analysis Team, Office of Strategic Programs

This fact sheet "Moab, Utah: Using Energy Data to Target Carbon Reductions from Building Energy Efficiency" explains how the City of Moab used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

New Haven, Connecticut: Targeting Low-Income Household Energy Savings (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strategic Priorities and Impact Analysis Team, Office of Strategic Programs

This fact sheet "New Haven, Connecticut: Targeting Low-Income Household Energy Savings" explains how the City of New Haven used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

Asheville, North Carolina: Reducing Electricity Demand through Building Programs & Policies (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

This fact sheet "Asheville, North Carolina: Reducing Electricity Demand through Building Programs & Policies" explains how the City of Asheville used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

STS-58 crewmembers participate in baseline data collection

NASA Image and Video Library

1993-09-29

S93-45368 (29 Sept 1993) --- Payload specialist Martin J. Fettman (face obscured), in an oscillating sled device, participates in a data collection project for neurovestibular functions. Assisting the test are Dr. Laurence Young, alternate payload specialist, and an unidentified MIT student. The seven Spacelab Life Sciences (SLS-2) crew members devoted a full day to miscellaneous biomedical data collection in preparation for next month's two week mission aboard Columbia.

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

San Jose, California: Evaluating Local Solar Energy Generation Potential (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

This fact sheet "San Jose, California: Evaluating Local Solar Energy Generation Potential" explains how the City of San Jose used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

This fact sheet "Carrboro, North Carolina: Achieving Building Efficiencies for Low-Income Households" explains how the Town of Carrboro used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

Boise, Idaho: Improving Air Quality through Alternative Fuels & Reduced Vehicular Travel (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strategic Priorities and Impact Analysis Team, Office of Strategic Programs

This fact sheet "Boise, Idaho: Improving Air Quality through Alternative Fuels & Reduced Vehicular Travel" explains how the City of Boise used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

Lafayette, Colorado: Using Energy Data for Electric Vehicle Infrastructure Planning (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

This fact sheet "Lafayette, Colorado: Using Energy Data for Electric Vehicle Infrastructure Planning" explains how the City of Lafayette used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochran, John R.

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 Areamore » [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.« less

Ice friction of flared ice hockey skate blades.

PubMed

Federolf, Peter A; Mills, Robert; Nigg, Benno

2008-09-01

In ice hockey, skating performance depends on the skill and physical conditioning of the players and on the characteristics of their equipment. CT Edge have recently designed a new skate blade that angles outward near the bottom of the blade. The objective of this study was to compare the frictional characteristics of three CT Edge blades (with blade angles of 4 degrees, 60, and 8 degrees, respectively) with the frictional characteristics of a standard skate blade. The friction coefficients of the blades were determined by measuring the deceleration of an aluminium test sled equipped with three test blades. The measurements were conducted with an initial sled speed of 1.8 m s(-1) and with a load of 53 kg on each blade. The friction coefficient of the standard blades was 0.0071 (s = 0.0005). For the CT Edge blades with blade angles of 4 degrees, 6 degrees, and 8 degrees, friction coefficients were lower by about 13%, 21%, and 22%, respectively. Furthermore, the friction coefficients decreased with increasing load. The results of this study show that widely accepted paradigms such as "thinner blades cause less friction" need to be revisited. New blade designs might also be able to reduce friction in speed skating, figure skating, bobsledding, and luge.

Evaluation of the effectiveness of toe board energy-absorbing material for foot, ankle, and lower leg injury reduction.

PubMed

Patalak, John P; Stitzel, Joel D

2018-02-17

Since 2000, numerous improvements have been made to the National Association for Stock Car Auto Racing, Incorporated (NASCAR®) driver restraint system, resulting in improved crash protection for motorsports drivers. Advancements have included seats, head and neck restraints (HNRs), seat belt restraint systems, driver helmets, and others. These enhancements have increased protection for drivers from severe crash loading. Extending protection to the driver's extremities remains challenging. Though the drivers' legs are well contained for lateral and vertical crashes, they remain largely unrestrained in frontal and frontal oblique crashes. Sled testing was conducted for the evaluation of an energy-absorbing (EA) toe board material to be used as a countermeasure for leg and foot injuries. Testing included baseline rigid toe boards, tests with EA material-covered toe boards, and pretest positioning of the 50th percentile male frontal Hybrid III anthropomorphic test device (ATD) lower extremities. ATD leg and foot instrumentation included foot acceleration and tibia forces and moments. The sled test data were evaluated using established injury criteria for tibial plateau fractures, leg shaft fractures, and calcaneus, talus, ankle, and midfoot fractures. A polyurethane EA foam was found to be effective in limiting axial tibia force and foot accelerations when subjected to frontal impacts using the NASCAR motorsport restraint system.

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.

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.

Practical use of high-speed cameras for research and development within the automotive industry: yesterday and today

NASA Astrophysics Data System (ADS)

Steinmetz, Klaus

1995-05-01

Within the automotive industry, especially for the development and improvement of safety systems, we find a lot of high accelerated motions, that can not be followed and consequently not be analyzed by human eye. For the vehicle safety tests at AUDI, which are performed as 'Crash Tests', 'Sled Tests' and 'Static Component Tests', 'Stalex', 'Hycam', and 'Locam' cameras are in use. Nowadays the automobile production is inconceivable without the use of high speed cameras.

South Lake Tahoe, California: Using Energy Data to Partner on Building Energy Efficiency Actions (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strategic Priorities and Impact Analysis Team, Office of Strategic Programs

This fact sheet "South Lake Tahoe, California: Using Energy Data to Partner on Building Energy Efficiency Actions" explains how the City of South Lake Tahoe used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

Columbia, Missouri: Using Energy Data to Reduce Emissions and Achieve Low-Income Household Energy Savings (City Energy: From Data to Decisions)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

This fact sheet "Columbia, Missouri: Using Energy Data to Reduce Emissions and Achieve Low-Income Household Energy Savings" explains how the City of Columbia used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

Simulation of Blast on Porcine Head

DTIC Science & Technology

2015-07-01

human cadaver heads (Wayne State Tolerance Curve), and concussive data from animals as well as long-duration human sled experiments have led to the...99% probability of producing concussion in Rhesus monkeys (whiplash injury on the sagittal plane) (Ommaya et al. 1967). However, since a single...correlated to brain injury—the critical rotation velocity ωcr = 42.1 rad/s and the critical acceleration αcr = 363 krad/ s2 for college football data

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

A Prediction of Response of the Head and Neck of the U.S. Adult Military Population to Dynamic Impact Acceleration from Selected Dynamic Test Subjects.

DTIC Science & Technology

1976-05-01

to Review Grants for Clinical Research and Investigation Involving Human Beings, Medical School, The University of Michigan. 3 of biomechanical models...human volunteers in dynamic sled tests found no clinically observable effects. due to acceleration on a subject in which the peak mouth angular...minutes cf rest between trials , and the average fo-ce of each set computed. Figure 2.7 shows typi- cal forcc curves and the EMG signal resulting from

Robotic Ground-Penetrating-Radar (GPR) Surveys to Support the 2014 Greenland Inland Traverse

DTIC Science & Technology

2016-06-01

based on the same lithium - ion batteries that power Yeti and integrated it within the SIR-30’s enclosure. We also built a light- weight sled to tow...Development Center (ERDC) solves the nation’s toughest engineering and environmental challenges. ERDC develops innovative solutions in civil and...sensing platforms. Results Yeti is an 81 kg, 4-wheel drive, battery -powered rover co-developed by Dartmouth College and CRREL (cover photo). In 2014

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

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

Automatic circuit interrupter

NASA Technical Reports Server (NTRS)

Dwinell, W. S.

1979-01-01

In technique, voice circuits connecting crew's cabin to launch station through umbilical connector disconnect automatically unused, or deadened portion of circuits immediately after vehicle is launched, eliminating possibility that unused wiring interferes with voice communications inside vehicle or need for manual cutoff switch and its associated wiring. Technique is applied to other types of electrical actuation circuits, also launch of mapped vehicles, such as balloons, submarines, test sleds, and test chambers-all requiring assistance of ground crew.

Carbon and Metal Transformations Near the Continent-Ocean Margin Quantified with the ZAPS Instrument Package

DTIC Science & Technology

1999-09-30

Rudnicki M.D. and Klinkhammer G.P., (1999) A segment-scale survey of the Broken Spur hydrothermal plume , Deep-Sea Res. I, 46, 701-714. Guay C.K...We used our sled this year to explore the Bransfield Strait, Antarctica for hydrothermal vent sites (NSF -Office of Polar Programs; OPP-9725872). We...used the real time sensing capability to locate a vent field and map hydrothermal signals at several locations. We used the ZAPS package to investigate

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.

Scalable Testing Platform for CMOS Read In Integrated Circuits

DTIC Science & Technology

2016-03-31

light - emitting - diode (SLED) current on a monitor out (MOUT) pin. The MOUT pin can produce voltage or current readings, depending on the test case. The...in it means the SPI communication works correctly. Lighting up LEDs: All the RIICs have the corner pixels brought out to output pins. Thus...external LEDs can be connected to pins in order to test the behavior of the pixel drive circuitry. Lighting up LEDs is a great visual representation that

Perception of linear acceleration in weightlessness

NASA Technical Reports Server (NTRS)

Arrott, A. P.; Young, L. R.

1987-01-01

Eye movements and subjective detection of acceleration were measured on human experimental subjects during vestibular sled acceleration during the D1 Spacelab Mission. Methods and results are reported on the time to detection of small acceleration steps, the threshold for detection of linear acceleration, perceived motion path, and CLOAT. A consistently shorter time to detection of small acceleration steps is found. Subjective reports of perceived motion during sinusoidal oscillation in weightlessness were qualitatively similar to reports on earth.

Muscle Adaptations Permitting Fatigue-Resistant Exercise

DTIC Science & Technology

2014-09-15

dietary composition in which fat is the predominant calorie source, that long-distance racing sled dogs sustain exercise by high oxidation rates of free...dog is fed a diet that is approximately 33% protein, 50% fat , and 16% CHO (Eagle Ultrapack, NPAL Analysis). If we assume 10,000 kcal/day intake...the 16% CHO is below what is considered a high CHO diet , which can reach values of 64% in highly trained cyclists during competition. However, the

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 themore » 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.« less

"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)

M.I.T./Canadian vestibular experiments on the Spacelab-1 mission: 6. Vestibular reactions to lateral acceleration following ten days of weightlessness

NASA Technical Reports Server (NTRS)

Arrott, A. P.; Young, L. R.

1986-01-01

Tests of otolith function were performed pre-flight and post-flight on the science crew of the first Spacelab Mission with a rail-mounted linear acceleration sled. Four tests were performed using horizontal lateral (y-axis) acceleration: perception of linear motion, a closed loop nulling task, dynamic ocular torsion, and lateral eye deviations. The motion perception test measured the time to detect the onset and direction of near threshold accelerations. Post-flight measures of threshold and velocity constant obtained during the days immediately following the mission showed no consistent pattern of change among the four crewmen compared to their pre-flight baseline other than an increased variability of response. In the closed loop nulling task, crewmen controlled the motion of the sled and attempted to null a computer-generated random disturbance motion. When performed in the light, no difference in ability was noted between pre-flight and post-flight. In the dark, however, two of the four crewmen exhibited somewhat enhanced performance post-flight. Dynamic ocular torsion was measured in response to sinusoidal lateral acceleration which produces a gravitionertial stimulus equivalent to lateral head tilt without rotational movement of the head. Results available for two crewmen suggest a decreased amplitude of sinusoidal ocular torsion when measured on the day of landing (R+0) and an increasing amplitude when measured during the week following the mission.

A population-based study of sport and recreation-related head injuries treated in a Canadian health region.

PubMed

Harris, Andrew W; Jones, C Allyson; Rowe, Brian H; Voaklander, Donald C

2012-07-01

To report the rates of SR-related HIs presenting to EDs in a Canadian population-based sample. Descriptive epidemiology study. Using administrative data, sport and recreation-related emergency department presentations for persons 0-35 years of age, from April 1997 through March 2008, were obtained from the Edmonton Zone (formerly the Capital Health Region), Alberta Health Services through the Ambulatory Care Classification System. Of the 3,230,890 visits to the emergency departments of the five hospitals in Edmonton, 63,219 sport and recreation-related injury records and 4935 sport and recreation-head injury records were identified. Head injuries were most frequently treated for the activities of hockey (20.7%), cycling (12.0%), and skiing/snowboarding/sledding. Males accounted for 71.9% (n=3546) and patients less than 18 years of age sustained 3446 (69.8%) sport and recreation-head injuries. Sport and recreation-related head injuries most frequently treated in emergency departments involve common activities such as hockey, cycling, skiing/snowboarding/sledding, and soccer. Males and those less than 18 years of age sustain the majority of sport and recreation-related head injuries treated in emergency departments. These findings underscore the importance of sport-specific policies and safety promotion for the prevention of head injuries, in sports and recreational activities. Copyright © 2011 Sports Medicine Australia. All rights reserved.

Environmental Restoration (ER) Consolidated Quarterly Report_April to June 2017_ October 2017

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochran, John R.

2017-10-01

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 April, May, and June 2017 quarterly reporting period. Table I-1 lists the Solid Waste Management Units (SWMUs) and Areas of Concern (AOCs) identified for corrective action at SNL/NM. 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 Groundwatermore » [TAVG AOC], and Tijeras Arroyo Groundwater [TAG AOC]). Section I.2.2 summarizes quarterly activities at sites where the New Mexico Environment Department (NMED) Hazardous Waste Bureau (HWB) 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 mission sites are located in TA-III.« less

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

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

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

NGEE Arctic Zero Power Warming PhenoCamera Images, Barrow, Alaska, 2016

DOE Data Explorer

Shawn Serbin; Andrew McMahon; Keith Lewin; Kim Ely; Alistair Rogers

2016-11-14

StarDot NetCam SC pheno camera images collected from the top of the Barrow, BEO Sled Shed. The camera was installed to monitor the BNL TEST group's prototype ZPW (Zero Power Warming) chambers during the growing season of 2016 (including early spring and late fall). Images were uploaded to the BNL FTP server every 10 minutes and renamed with the date and time of the image. See associated data "Zero Power Warming (ZPW) Chamber Prototype Measurements, Barrow, Alaska, 2016" http://dx.doi.org/10.5440/1343066.

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.

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

Bumper and grille airbags concept for enhanced vehicle compatibility in side impact: phase II.

PubMed

Barbat, Saeed; Li, Xiaowei; Prasad, Priya

2013-01-01

Fundamental physics and numerous field studies have shown a higher injury and fatality risk for occupants in smaller and lighter vehicles when struck by heavier, taller and higher vehicles. The consensus is that the significant parameters influencing compatibility in front-to-side crashes are geometric interaction, vehicle stiffness, and vehicle mass. The objective of this research is to develop a concept of deployable bumper and grille airbags for improved vehicle compatibility in side impact. The external airbags, deployed upon signals from sensors, may help mitigate the effect of weight, geometry and stiffness differences and reduce side intrusions. However, a highly reliable pre-crash sensing system is required to enable the reliable deployment, which is currently not technologically feasible. Analytical and numerical methods and hardware testing were used to help develop the deployable external airbags concept. Various Finite Element (FE) models at different stages were developed and an extensive number of iterations were conducted to help optimize airbag and inflator parameters to achieve desired targets. The concept development was executed and validated in two phases. This paper covers Phase II ONLY, which includes: (1) Re-design of the airbag geometry, pressure, and deployment strategies; (2) Further validation using a Via sled test of a 48 kph perpendicular side impact of an SUV-type impactor against a stationary car with US-SID-H3 crash dummy in the struck side; (3) Design of the reaction surface necessary for the bumper airbag functionality. The concept was demonstrated through live deployment of external airbags with a reaction surface in a full-scale perpendicular side impact of an SUV against a stationary passenger car at 48 kph. This research investigated only the concept of the inflatable devices since pre-crash sensing development was beyond the scope of this research. The concept design parameters of the bumper and grille airbags are presented in

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).

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.

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

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.

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.

Along-axis variations in seafloor spreading in the MARK area

NASA Astrophysics Data System (ADS)

Karson, J. A.; Thompson, G.; Humphris, S. E.; Bryan, W. B.; Edmond, J. M.

1987-08-01

Recent investigations with the manned submersible Alvin and the Angus deep-towed camera sled greatly extended the known range of variations in the style of seafloor spreading along the axis of the Mid-Atlantic Ridge. Five transects of the spreading center at intervals of 10-20 km south of the Kane Fracture Zone at 24 deg N latitude demonstate dramatic changes in the style and magnitude of tectonic extension, development of the neovolcanic zone, expression of hydrothermal venting, types of lithologic exposures, and morphology of the median valley.

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.

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…

Computational Aerodynamic Analysis of the Flow Field about a Hypervelocity Test Sled

DTIC Science & Technology

2002-03-01

scheme would capture the steady solution without the convergence difficulties. 6-3 Bibliography 1. Amtec Engineering Incorporated, Bellevue WA. CFD...Analyzer User’s Manual, Version 2.0 , 1999. Electronic documentation, http://www.amtec.com. 2. Amtec Engineering Incorporated, Bellevue WA. Tecplot User’s

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.

Quasi-Static and Dynamic Sled Testing of Prototype Commuter Rail Passenger Seats

DOT National Transportation Integrated Search

2008-04-22

In support of the Federal Railroad Administration?s (FRA) Railroad Equipment Safety Program, tests have been conducted on prototype commuter rail passenger seats which have been designed for improved occupant protection during commuter train accident...

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.

Pressure mapping to assess seated pressure distributions and the potential risk for skin ulceration in a population of sledge hockey players and control subjects.

PubMed

Berthold, Justin; Dicianno, Brad E; Cooper, Rory A

2013-09-01

Ice sledge (or sled) hockey is a fast-paced sport that enables individuals with physical disabilities to play ice hockey. As the attraction to the sport continues to rise, the need for developing better equipment and installing preventative measures for injury will become increasingly important. One such injury includes skin pressure ulceration. A total of 26 subjects including active controls and those with spinal cord injury, multiple sclerosis, limb amputation and traumatic brain injury were studied using a pressure mapping device at the 2012 National Disabled Veterans Winter Sports Clinic to determine the risk for skin pressure ulceration and the impact of cushioning and knee angle positioning on seated pressure distributions. Sledge hockey athletes may be at increased risk for skin pressure ulceration based on seated pressure distribution data. This experiment failed to demonstrate a benefit for specialty cushioning in either group. Interestingly, knee angle positioning, particularly, knee extension significantly lowered the average seated pressures. When considering the risk for skin pressure ulceration, knee angle positioning is of particular clinical importance. More research is warranted, specifically targeting novel cushion and sledge designs and larger groups of individuals with sensory loss and severe spinal deformities. Implications for Rehabilitation Ice sledge (or sled) hockey is a fast-paced and growing adaptive sport played at the Paralympic level. Rehabilitation professionals should consider the potential for skin ulceration in this population of athletes. The effects of cushioning used in the sledge design warrants further investigation. Knee angle positioning; particularly, knee extension significantly lowers seated pressures and may reduce the potential for skin ulceration.

Impact of alignment to gravito-inertial force on motion sickness and cardiopulmonary variables.

PubMed

Mert, Agali; Bles, Willem

2011-07-01

In tilting trains partial alignment to the gravito-inertial force (GIF) in the curves seems to be the best tilt compensation to reduce the incidence of motion sickness. We investigated the effect of alignment to the GIF on the development of motion sickness during low-frequency horizontal motion. There were 12 healthy subjects who participated. The design was a three-period, single-blind, crossover trial, counterbalanced for order. Cardiopulmonary measurements, Misery SCores (MISC), and questionnaire data (Motion Sickness Susceptibility Questionnaire, Nijmegen Questionnaire for Hyperventilation) were obtained. The stimulus was a sinusoidal movement (0.176 Hz, 0.2 g peak acceleration) on the ESA-sled. The cabin was compensated for 0% (A-0), 50% (A-50), and 100% (A-100) to the GIF. Runs were 1 wk apart. The A-50 condition may delay the development of motion sickness. Based on the survival curves the possible effect seems temporary. However, MISC 2 early in the runs resulted in high positive and negative predictive values for dropout and survival during the runs. No synchronization of the respiratory frequency with the sled motion was observed. There was a significant (P = 0.002) drop in relative end-tidal CO2 levels. There seems to be a rationale for partially compensating to the GIF while trying to prevent motion sickness in tilting trains. Sitting comfort is just better than without compensation at all and Coriolis effects are not as nauseating as with complete tilt compensation. Also, a drop in end-tidal CO2 levels might be a sign of pulmonary compensation for the nauseating stimulus.

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.

Multiwavelength Characterization of an ACT-selected, Lensed Dusty Star-forming Galaxy at z = 2.64

NASA Astrophysics Data System (ADS)

Roberts-Borsani, G. W.; Jiménez-Donaire, M. J.; Daprà, M.; Alatalo, K.; Aretxaga, I.; Álvarez-Márquez, J.; Baker, A. J.; Fujimoto, S.; Gallardo, P. A.; Gralla, M.; Hilton, M.; Hughes, J. P.; Jiménez, C.; Laporte, N.; Marriage, T. A.; Nati, F.; Rivera, J.; Sievers, A.; Weiß, A.; Wilson, G. W.; Wollack, E. J.; Yun, M. S.

2017-08-01

We present C I(2-1) and multi-transition 12CO observations of a dusty star-forming galaxy, ACT J2029+0120, which we spectroscopically confirm to lie at z = 2.64. We detect CO(3-2), CO(5-4), CO(7-6), CO(8-7), and C I(2-1) at high significance, tentatively detect HCO+(4-3), and place strong upper limits on the integrated strength of dense gas tracers (HCN(4-3) and CS(7-6)). Multi-transition CO observations and dense gas tracers can provide valuable constraints on the molecular gas content and excitation conditions in high-redshift galaxies. We therefore use this unique data set to construct a CO spectral line energy distribution (SLED) of the source, which is most consistent with that of a ULIRG/Seyfert or QSO host object in the taxonomy of the Herschel Comprehensive ULIRG Emission Survey. We employ RADEX models to fit the peak of the CO SLED, inferring a temperature of T ˜ 117 K and {n}{{{H}}2}˜ {10}5 cm-3, most consistent with a ULIRG/QSO object and the presence of high-density tracers. We also find that the velocity width of the C I line is potentially larger than seen in all CO transitions for this object, and that the {L}{{C} {{I}}(2-1)}\\prime /{L}{CO(3-2)}\\prime ratio is also larger than seen in other lensed and unlensed submillimeter galaxies and QSO hosts; if confirmed, this anomaly could be an effect of differential lensing of a shocked molecular outflow.

Multi-wavelength mid-IR light source for gas sensing

NASA Astrophysics Data System (ADS)

Karioja, Pentti; Alajoki, Teemu; Cherchi, Matteo; Ollila, Jyrki; Harjanne, Mikko; Heinilehto, Noora; Suomalainen, Soile; Viheriälä, Jukka; Zia, Nouman; Guina, Mircea; Buczyński, Ryszard; Kasztelanic, Rafał; Kujawa, Ireneusz; Salo, Tomi; Virtanen, Sami; Kluczyński, Paweł; Sagberg, Hâkon; Ratajczyk, Marcin; Kalinowski, Przemyslaw

2017-02-01

Cost effective multi-wavelength light sources are key enablers for wide-scale penetration of gas sensors at Mid-IR wavelength range. Utilizing novel Mid-IR Si-based photonic integrated circuits (PICs) filter and wide-band Mid-IR Super Luminescent Light Emitting Diodes (SLEDs), we show the concept of a light source that covers 2.5…3.5 μm wavelength range with a resolution of <1nm. The spectral bands are switchable and tunable and they can be modulated. The source allows for the fabrication of an affordable multi-band gas sensor with good selectivity and sensitivity. The unit price can be lowered in high volumes by utilizing tailored molded IR lens technology and automated packaging and assembling technologies. The status of the development of the key components of the light source are reported. The PIC is based on the use of micron-scale SOI technology, SLED is based on AlGaInAsSb materials and the lenses are tailored heavy metal oxide glasses fabricated by the use of hot-embossing. The packaging concept utilizing automated assembly tools is depicted. In safety and security applications, the Mid-IR wavelength range covered by the novel light source allows for detecting several harmful gas components with a single sensor. At the moment, affordable sources are not available. The market impact is expected to be disruptive, since the devices currently in the market are either complicated, expensive and heavy instruments, or the applied measurement principles are inadequate in terms of stability and selectivity.

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. © The Author(s) 2016.

Multiwavelength Characterization of an ACT-Selected, Lensed Dusty Star-Forming Galaxy at zeta 2.64

NASA Technical Reports Server (NTRS)

Roberts-Borsani, G. W.; Jimenez-Donaire, M. J.; Dapra, M.; Alatalo, K.; Aretxaga, I.; Alvarez-Marquez, J.; Baker, A. J.; Fujimoto, S.; Gallardo, P. A.; Gralla, M.;

Environmental Restoration Operations: Consolidated Quarterly Report January -March 2017

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochran, John R.

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 January, February, and March 2017 quarterly reporting period. Table I-1 lists the Solid Waste Management Units (SWMUs) and Areas of Concern (AOCs) identified for corrective action at SNL/NM. 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 Groundwatermore » [TAVG AOC], and Tijeras Arroyo Groundwater [TAG AOC]). Section I.2.2 summarizes quarterly activities at sites where the New Mexico Environment Department (NMED) Hazardous Waste Bureau (HWB) 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 mission sites are located in TA-III. This Sandia National Laboratories, New Mexico Environmental Restoration Operations (ER) Consolidated Quarterly Report (ER Quarterly Report) fulfills all quarterly reporting requirements set forth in the Resource Conservation and Recovery Act Facility Operating Permit and the Compliance Order on Consent.« less

NASA general aviation crashworthiness seat development

NASA Technical Reports Server (NTRS)

Fasanella, E. L.; Alfaro-Bou, E.

1979-01-01

Three load limiting seat concepts for general aviation aircraft designed to lower the deceleration of the occupant in the event of a crash were sled tested and evaluated with reference to a standard seat. Dummy pelvis accelerations were reduced up to 50 percent with one of the concepts. Computer program MSOMLA (Modified Seat Occupant Model for Light Aircraft) was used to simulate the behavior of a dummy passenger in a NASA full-scale crash test of a twin engine light aircraft. A computer graphics package MANPLOT was developed to pictorially represent the occupant and seat motion.

Vehicle interior interactions and kinematics of rear facing child restraints in frontal crashes.

PubMed

Sherwood, C P; Gopalan, S; Abdelilah, Y; Marshall, R J; Crandall, J R

2005-01-01

The performance of rear facing child restraints in frontal crashes can be determined by controlling a) the child's kinematics and b) interactions with vehicle structures. Twelve sled tests were performed to analyze the effect of the location and structural properties of vehicle interior components. The role of restraint kinematics was studied by developing computational models which underwent idealized motions. Stiff structures originally offset from the restraint, but which contact the restraint late in the test, cause increased injury values. Attachment methods which reduce child restraint rotation and more rigidly couple the restraint to the vehicle result in the best safety performance.

Mid-J CO Shock Tracing Observations of Infrared Dark Clouds. III. SLED Fitting

NASA Astrophysics Data System (ADS)

Pon, A.; Kaufman, M. J.; Johnstone, D.; Caselli, P.; Fontani, F.; Butler, M. J.; Jiménez-Serra, I.; Palau, A.; Tan, J. C.

2016-08-01

Giant molecular clouds contain supersonic turbulence that can locally heat small fractions of gas to over 100 K. We run shock models for low-velocity, C-type shocks propagating into gas with densities between 103 and 105 cm-3 and find that CO lines are the most important cooling lines. Comparison to photodissociation region (PDR) models indicates that mid-J CO lines (J = 8 \\to 7 and higher) should be dominated by emission from shocked gas. In Papers I and II we presented CO J = 3 \\to 2, 8 \\to 7, and 9 \\to 8 observations toward four primarily quiescent clumps within infrared dark clouds. Here we fit PDR models to the combined spectral line energy distributions and show that the PDR models that best fit the low-J CO emission underpredict the mid-J CO emission by orders of magnitude, strongly hinting at a hot gas component within these clumps. The low-J CO data clearly show that the integrated intensities of both the CO J = 8 \\to 7 and 9 \\to 8 lines are anomalously high, such that the line ratio can be used to characterize the hot gas component. Shock models are reasonably consistent with the observed mid-J CO emission, with models with densities near {10}4.5 cm-3 providing the best agreement. Where this mid-J CO is detected, the mean volume filling factor of the hot gas is 0.1%. Much of the observed mid-J CO emission, however, is also associated with known protostars and may be due to protostellar feedback.

Evaluation of the hybrid III and Q-series pediatric ATD upper neck loads as compared to pediatric volunteers in low-speed frontal crashes.

PubMed

Seacrist, Thomas; Mathews, Emily A; Balasubramanian, Sriram; Maltese, Matthew R; Arbogast, Kristy B

2013-11-01

Debate exists in the automotive community regarding the validity of the pediatric ATD neck response and corresponding neck loads. Previous research has shown that the pediatric ATDs exhibit hyper-flexion and chin-to-chest contact resulting in overestimations of neck loads and neck injury criteria. Our previous work comparing the kinematics of the Hybrid III and Q-series 6 and 10-year-old ATDs to pediatric volunteers in low-speed frontal sled tests revealed decreased ATD cervical and thoracic spine excursions. These kinematic differences may contribute to the overestimation of upper neck loads by the ATD. The current study compared upper neck loads of the Hybrid III and Q-series 6 and 10-year-old ATDs against size-matched male pediatric volunteers in low-speed frontal sled tests. A 3-D near-infrared target tracking system quantified the position of markers on the ATD and pediatric volunteers (head top, nasion, bilateral external auditory meatus). Shear force (F x ), axial force (F z ), bending moment (M y ), and head angular acceleration ([Formula: see text]) were calculated about the upper neck using standard equations of motion. In general, the ATDs underestimated axial force and overestimated bending moment compared to the human volunteers. The Hybrid III 6, Q6, and Q10 exhibited reduced head angular acceleration and modest increases in upper neck shear compared to the pediatric volunteers. The reduction in axial force and bending moment has important implications for neck injury predictions as both are used when calculating N ij . These analyses provide insight into the biofidelity of the pediatric ATD upper neck loads in low-speed crash environments.

Estimation of muscle response using three-dimensional musculoskeletal models before impact situation: a simulation study.

PubMed

Bae, Tae Soo; Loan, Peter; Choi, Kuiwon; Hong, Daehie; Mun, Mu Seong

2010-12-01

When car crash experiments are performed using cadavers or dummies, the active muscles' reaction on crash situations cannot be observed. The aim of this study is to estimate muscles' response of the major muscle groups using three-dimensional musculoskeletal model by dynamic simulations of low-speed sled-impact. The three-dimensional musculoskeletal models of eight subjects were developed, including 241 degrees of freedom and 86 muscles. The muscle parameters considering limb lengths and the force-generating properties of the muscles were redefined by optimization to fit for each subject. Kinematic data and external forces measured by motion tracking system and dynamometer were then input as boundary conditions. Through a least-squares optimization algorithm, active muscles' responses were calculated during inverse dynamic analysis tracking the motion of each subject. Electromyography for major muscles at elbow, knee, and ankle joints was measured to validate each model. For low-speed sled-impact crash, experiment and simulation with optimized and unoptimized muscle parameters were performed at 9.4 m/h and 10 m/h and muscle activities were compared among them. The muscle activities with optimized parameters were closer to experimental measurements than the results without optimization. In addition, the extensor muscle activities at knee, ankle, and elbow joint were found considerably at impact time, unlike previous studies using cadaver or dummies. This study demonstrated the need to optimize the muscle parameters to predict impact situation correctly in computational studies using musculoskeletal models. And to improve accuracy of analysis for car crash injury using humanlike dummies, muscle reflex function, major extensor muscles' response at elbow, knee, and ankle joints, should be considered.

CO line emission from galaxies in the Epoch of Reionization

NASA Astrophysics Data System (ADS)

Vallini, L.; Pallottini, A.; Ferrara, A.; Gallerani, S.; Sobacchi, E.; Behrens, C.

2018-01-01

We study the CO line luminosity (LCO), the shape of the CO spectral line energy distribution (SLED), and the value of the CO-to-H2 conversion factor in galaxies in the Epoch of Reionization (EoR). For this aim, we construct a model that simultaneously takes into account the radiative transfer and the clumpy structure of giant molecular clouds (GMCs) where the CO lines are excited. We then use it to post-process state-of-the-art zoomed, high resolution (30 pc), cosmological simulation of a main-sequence (M* ≈ 1010 M⊙, SFR ≈ 100 M⊙ yr- 1) galaxy, 'Althæa', at z ≈ 6. We find that the CO emission traces the inner molecular disc (r ≈ 0.5 kpc) of Althæa with the peak of the CO surface brightness co-located with that of the [C II] 158 μm emission. Its LCO(1-0) = 104.85 L⊙ is comparable to that observed in local galaxies with similar stellar mass. The high (Σgas ≈ 220 M⊙ pc- 2) gas surface density in Althæa, its large Mach number (M ≈ 30) and the warm kinetic temperature (Tk ≈ 45 K) of GMCs yield a CO SLED peaked at the CO(7-6) transition, i.e. at relatively high-J and a CO-to-H2 conversion factor α _CO≈ 1.5 M_{⊙} (K km s^{-1} pc^2)^{-1} lower than that of the Milky Way. The Atacama Large Millimeter/submillimeter Array observing time required to detect (resolve) at 5σ the CO(7-6) line from galaxies similar to Althæa is ≈13 h (≈38 h).

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.

Designing for aircraft structural crashworthiness

NASA Technical Reports Server (NTRS)

Thomson, R. G.; Caiafa, C.

1981-01-01

This report describes structural aviation crash dynamics research activities being conducted on general aviation aircraft and transport aircraft. The report includes experimental and analytical correlations of load-limiting subfloor and seat configurations tested dynamically in vertical drop tests and in a horizontal sled deceleration facility. Computer predictions using a finite-element nonlinear computer program, DYCAST, of the acceleration time-histories of these innovative seat and subfloor structures are presented. Proposed application of these computer techniques, and the nonlinear lumped mass computer program KRASH, to transport aircraft crash dynamics is discussed. A proposed FAA full-scale crash test of a fully instrumented radio controlled transport airplane is also described.

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.

Vehicle Interior Interactions and Kinematics of Rear Facing Child Restraints in Frontal Crashes

PubMed Central

Sherwood, C. P.; Gopalan, S.; Abdelilah, Y.; Marshall, R. J.; Crandall, J. R.

2005-01-01

The performance of rear facing child restraints in frontal crashes can be determined by controlling a) the child’s kinematics and b) interactions with vehicle structures. Twelve sled tests were performed to analyze the effect of the location and structural properties of vehicle interior components. The role of restraint kinematics was studied by developing computational models which underwent idealized motions. Stiff structures originally offset from the restraint, but which contact the restraint late in the test, cause increased injury values. Attachment methods which reduce child restraint rotation and more rigidly couple the restraint to the vehicle result in the best safety performance. PMID:16179150

Comparison of Q3s ATD biomechanical responses to pediatric volunteers.

PubMed

Ita, Meagan; Kang, Yun-Seok; Seacrist, Thomas; Dahle, Eric; Bolte, John

2014-01-01

The biofidelity of pediatric anthropomorphic test devices (ATDs) continues to be evaluated with scaled-down adult data, a methodology that requires inaccurate assumptions about the likeness of biomechanical properties of children and adults. Recently, evaluation of pediatric ATDs by comparison of pediatric volunteer (PV) data has emerged as a valuable and practical alternative to the use of scaled adult data. This study utilized existing PV data to evaluate a 3-year-old side impact ATD, the Q3s. Though ATDs have been compared to volunteer responses in frontal impacts, this study is the first to extend ATD-PV comparison methods to the Q3s ATD and among the first to extend these methods to side impacts. Previously conducted experiments were replicated in order to make a direct comparison between the Q3s and PVs. PV data were used from 4- to 7-year-olds (shoulder tests, n=14) and 6- to 8-year-olds (sled tests, n=7). Force-deflection data were captured during quasistatic shoulder tests through manual displacement of the shoulder joint. Resulting shoulder stiffness was compared between the Q3s and PVs. Low-speed far-side sled tests were conducted with the Q3s at lateral (90°) and oblique (60°) impacts. Primary outcomes of interest included (1) lateral displacement of the torso, (2) torso rollout angle, and (3) kinematic trajectories of the head and neck. The Q3s exhibited shoulder stiffness values at least 32 N/mm greater than the PVs for all conditions (PV muscle tensed and relaxed, deflection calculated for full- and half-thoracic). In lateral sled tests, the Q3s demonstrated increased coronal torso rollout (Q3s: 49.2°; PVs: 35.7°±12.4°) and lateral (ΔY) movement of the top of the head (Q3s: -389 mm; PVs: -320±23 mm) compared to PVs. In oblique trials, the Q3s achieved significantly decreased lateral torso displacement (Q3s: 153.3 mm; PVs: 193.6±25.6 mm) and top of the head forward (ΔX) motion (Q3s: 68 mm; PVs: 133 ± 20 mm) compared to PVs. In all tests

A 13-year analysis from Switzerland of non-fatal sledging (sledding or tobogganing) injuries.

PubMed

Heim, Dominik; Altgeld, Katrin; Hasler, Rebecca M; Aghayev, Emin; Exadaktylos, Aristomenis K

2014-01-01

Winter sports have evolved from an upper class activity to a mass industry. Especially sledging regained popularity at the start of this century, with more and more winter sports resorts offering sledge runs. This study investigated the rates of sledging injuries over the last 13 years and analysed injury patterns specific for certain age groups, enabling us to make suggestions for preventive measures. We present a retrospective analysis of prospectively collected data. From 1996/1997 to 2008/2009, all patients involved in sledging injuries were recorded upon admission to a Level III trauma centre. Injuries were classified into body regions according to the Abbreviated Injury Scale (AIS). The Injury Severity Score (ISS) was calculated. Patients were stratified into 7 age groups. Associations between age and injured body region were tested using the chi-squared test. The slope of the linear regression with 95% confidence intervals was calculated for the proportion of patients with different injured body regions and winter season. 4956 winter sports patients were recorded. 263 patients (5%) sustained sledging injuries. Sledging injury patients had a median age of 22 years (interquartile range [IQR] 14-38 years) and a median ISS of 4 (IQR 1-4). 136 (51.7%) were male. Injuries (AIS ≥ 2) were most frequent to the lower extremities (n=91, 51.7% of all AIS ≥ 2 injuries), followed by the upper extremities (n=48, 27.3%), the head (n=17, 9.7%), the spine (n=7, 4.0%). AIS ≥ 2 injuries to different body regions varied from season to season, with no significant trends (p>0.19). However, the number of patients admitted with AIS ≥ 2 injuries increased significantly over the seasons analysed (p=0.031), as did the number of patients with any kind of sledging injury (p=0.004). Mild head injuries were most frequent in the youngest age group (1-10 years old). Injuries to the lower extremities were more often seen in the age groups from 21 to 60 years (p<0.001). Mild head trauma was mainly found in very young sledgers, and injuries to the lower extremities were more frequent in adults. In accordance with the current literature, we suggest that sledging should be performed in designated, obstacle-free areas that are specially prepared, and that children should always be supervised by adults. The effect of routine use of helmets and other protective devices needs further evaluation, but it seems evident that these should be obligatory on official runs. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

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).

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.

Evaluation of Mid-Size Male Hybrid III Models for use in Spaceflight Occupant Protection Analysis

NASA Technical Reports Server (NTRS)

Putnam, J.; Somers, J.; Wells, J.; Newby, N.; Currie-Gregg, N.; Lawrence, C.

2016-01-01

Introduction: In an effort to improve occupant safety during dynamic phases of spaceflight, the National Aeronautics and Space Administration (NASA) has worked to develop occupant protection standards for future crewed spacecraft. One key aspect of these standards is the identification of injury mechanisms through anthropometric test devices (ATDs). Within this analysis, both physical and computational ATD evaluations are required to reasonably encompass the vast range of loading conditions any spaceflight crew may encounter. In this study the accuracy of publically available mid-size male HIII ATD finite element (FE) models are evaluated within applicable loading conditions against extensive sled testing performed on their physical counterparts. Methods: A series of sled tests were performed at the Wright Patterson Air force Base (WPAFB) employing variations of magnitude, duration, and impact direction to encompass the dynamic loading range for expected spaceflight. FE simulations were developed to the specifications of the test setup and driven using measured acceleration profiles. Both fast and detailed FE models of the mid-size male HIII were ran to quantify differences in their accuracy and thus assess the applicability of each within this field. Results: Preliminary results identify the dependence of model accuracy on loading direction, magnitude, and rate. Additionally the accuracy of individual response metrics are shown to vary across each model within evaluated test conditions. Causes for model inaccuracy are identified based on the observed relationships. Discussion: Computational modeling provides an essential component to ATD injury metric evaluation used to ensure the safety of future spaceflight occupants. The assessment of current ATD models lays the groundwork for how these models can be used appropriately in the future. Identification of limitations and possible paths for improvement aid in the development of these effective analysis tools.

Predicting the intensity mapping signal for multi-J CO lines

NASA Astrophysics Data System (ADS)

Mashian, Natalie; Sternberg, Amiel; Loeb, Abraham

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 ΔCO2 ~ 0.1 and 0.005 μK respectively, at k = 0.1 Mpc-1. In this model, the CO emission signal remains strong for higher rotational levels at z = 6, with langle TCO rangle ~ 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.

Energy-absorbing car seat designs for reducing whiplash.

PubMed

Himmetoglu, S; Acar, M; Bouazza-Marouf, K; Taylor, A J

2008-12-01

This study presents an investigation of anti-whiplash features that can be implemented in a car seat to reduce whiplash injuries in the case of a rear impact. The main emphasis is on achieving a seat design with good energy absorption properties. A biofidelic 50th percentile male multi-body human model for rear impact is developed to evaluate the performance of car seat design concepts. The model is validated using the responses of 7 volunteers from the Japanese Automobile Research Institute (JARI) sled tests, which were performed at an impact speed of 8 kph with a rigid seat and without head restraint and seatbelt. A generic multi-body car seat model is also developed to implement various seatback and recliner properties, anti-whiplash devices, and head restraints. Using the same driving posture and the rigid seat in the JARI sled tests as the basic configuration, several anti-whiplash seats are designed to allow different types of motion for the seatback and seat-pan. The anti-whiplash car seat design concepts limit neck internal motion successfully until the head-to-head restraint contact occurs and they exhibit low NIC(max) values (7 m(2)/s(2) on average). They are also effective in reducing neck compression forces and T1 forward accelerations. In principle, these car seat design concepts employ controlled recliner rotation and seat-pan displacement to limit the formation of S-shape. This is accomplished by using anti-whiplash devices that absorb the crash energy in such a way that an optimum protection is provided at different severities. The results indicate that the energy absorbing car seat design concepts all demonstrate good whiplash-reducing performances at the IIWPG standard pulse. Especially in higher severity rear impacts, two of the car seat design concepts reduce the ramping of the occupant considerably.

Repeat Effort Performance is Reduced 24 h following Acute Dehydration in Mixed Martial Arts Athletes.

PubMed

Barley, Oliver R; Iredale, Fiona; Chapman, Dale W; Hopper, Amanda; Abbiss, Chris

2017-09-11

This study sought to determine the influence of acute dehydration on physical performance and physiology in Mixed Martial Arts (MMA). MMA athletes (n=14; age: 23±4 years), completed in a randomised counterbalanced order a dehydration protocol, (DHY: 3 h cycling at 60 W in 40°C to induce 5% dehydration) or thermoneutral control (25°C: CONT) exercise, followed by ad libitum fluid/food intake. Performance testing (a repeat sled push test, medicine ball chest throw and vertical jump) was completed 3 and 24 h following the intervention, while urine and blood samples were collected before, 20 min, 3 and 24 h following the intervention. Body mass was reduced (4.8±0.8%) following DHY (p<0.001) and remained lower than CONT at 3 and 24 h post (p=0.003 and p=0.024, respectively). Compared to CONT average sled push times were slower 3 and 24 h following DHY (19±15%; p=0.001; g=1.229 and 14±15%; p=0.012; g=0.671, respectively). When compared to the CONT hand grip was weaker 3 h following DHY (53±8 and 51±8 kg; p=0.044, g=0.243 respectively) and medicine ball chest throw distances were shorter 24 h following DHY (474±52 and 449±44 cm; p=0.016, g=0.253 respectively). No significant differences were observed in vertical jump (p=0.467). Urine specific gravity was higher than CONT 20 min (p=0.035) and 24 h (p=0.035) following DHY. Acute dehydration of 4.8% body mass results in reduced physical performance 3 and 24 h following. There is need for caution when athletes use dehydration for weight loss 24 h prior to competition.

Echinococcus canadensis transmission in the North.

PubMed

Oksanen, Antti; Lavikainen, Antti

2015-10-30

The Echinococcus granulosus complex (EG) is the causative agent of cystic echinococcosis (CE). Northern cervid Echinococcus was previously suggested to be the ancestor of the entire EG. During the last century, it was regarded to have three (or four) different, but often overlapping, transmission cycles in the circumpolar North: the original wolf-wild cervid (reindeer or elk)-cycle; the semi-synanthropic cycle involving sled and hunting dogs and wild cervids; and the synanthropic cycle involving herding dogs and semi-domesticated reindeer. Human infections mainly derived from the latter two cycles. In Fennoscandia, the synanthropic cycle has been eliminated during the last 50 years due to changes in reindeer husbandry methods; machinery making herding dogs largely redundant. Typical to human CE in the North has been the relatively benign nature of the disease compared with CE caused by E. granulosus sensu stricto. The metacestodes in humans and in the natural cervid hosts predominantly appear in the lungs. The causative agents have been identified as EG mitochondrial genotypes G8 and G10, now together with G6 (camel), G7 (pig) and G9 genotypes constituting the Echinococcus canadensis species. Based on recent findings in reindeer in Yakutia, G6 might also be recognised among cervid genotypes. The geographical distribution of both G8 and G10 is circumpolar, with G10 currently apparently more prevalent both in the Palearctic and Nearctic. Because of the disappearance of the working dog, E. canadensis in Fennoscandia is again highly dependent on the wolf, as it was before domestication of the dog. Pet and sled dogs, if their number further increases, may to a minor part participate in the life cycle. Human CE in the North was mostly diagnosed by mass chest tuberculosis radiography campaigns, which have been discontinued. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of Mid-Size Male Hybrid III Models for use in Spaceflight Occupant Protection Analysis

NASA Technical Reports Server (NTRS)

Putnam, Jacob B.; Sommers, Jeffrey T.; Wells, Jessica A.; Newby, Nathaniel J.; Currie-Gregg, Nancy J.; Lawrence, Chuck

2016-01-01

In an effort to improve occupant safety during dynamic phases of spaceflight, the National Aeronautics and Space Administration (NASA) has worked to develop occupant protection standards for future crewed spacecraft. One key aspect of these standards is the identification of injury mechanisms through anthropometric test devices (ATDs). Within this analysis, both physical and computational ATD evaluations are required to reasonably encompass the vast range of loading conditions any spaceflight crew may encounter. In this study the accuracy of publically available mid-size male HIII ATD finite element (FE) models are evaluated within applicable loading conditions against extensive sled testing performed on their physical counterparts. Methods: A series of sled tests were performed at the Wright Patterson Air force Base (WPAFB) employing variations of magnitude, duration, and impact direction to encompass the dynamic loading range for expected spaceflight. FE simulations were developed to the specifications of the test setup and driven using measured acceleration profiles. Both fast and detailed FE models of the mid-size male HIII were ran to quantify differences in their accuracy and thus assess the applicability of each within this field. Results: Preliminary results identify the dependence of model accuracy on loading direction, magnitude, and rate. Additionally the accuracy of individual response metrics are shown to vary across each model within evaluated test conditions. Causes for model inaccuracy are identified based on the observed relationships. Discussion: Computational modeling provides an essential component to ATD injury metric evaluation used to ensure the safety of future spaceflight occupants. The assessment of current ATD models lays the groundwork for how these models can be used appropriately in the future. Identification of limitations and possible paths for improvement aid in the development of these effective analysis tools.

Worldsid Assessment of Far Side Impact Countermeasures

PubMed Central

Pintar, Frank A.; Yoganandan, Narayan; Stemper, Brian D.; Bostrom, Ola; Rouhana, Stephen W.; Smith, Stuart; Sparke, Laurie; Fildes, Brian N.; Digges, Kennerly H.

2006-01-01

Far side impact trauma has been demonstrated as a significant portion of the total trauma in side impacts. The objective of the study was to assess the potential usefulness of countermeasures and assess the trade-offs associated with generic countermeasure design. Because the WorldSID dummy has demonstrated promise as a potential far side impact dummy, it was chosen to assess countermeasures in this mode. A unique far side impact buck was designed for a sled test system that included, as a standard configuration, a center console and outboard three-point belt system. This configuration assumed a left side driver with a right side impact. The buck allowed for additional options of generic restraints 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 19 WorldSID tests were completed. The inboard shoulder belt configuration produced high shear forces in the lower neck (2430 N) when the belt position was placed over the mid portion of the neck. Shear forces were reduced and of opposite sign when the inboard belt position was horizontal and over the shoulder; forces were similar to the standard outboard belt configuration (830 – 1100 N). A shoulder or thorax restraint was effective in limiting the head excursion, but each caused significant displacement at the corresponding region on the dummy. A shoulder restraint resulted in shoulder displacements of 30 – 43 mm. A thorax restraint caused thorax deflections of 39 – 64 mm. Inboard restraints for far side impacts can be effective in reducing head excursion but the specific design and placement of these restraints determine their overall injury mitigating characteristics. PMID:16968638

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.

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

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.

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lockner, Thomas Ramsbeck; Skurdal, Ben; Gaigler, Randy

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, specificmore » pulsed power system component details, system operation, and demonstration results.« less

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.

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.

MIT-KSC space life sciences telescience testbed

NASA Technical Reports Server (NTRS)

1989-01-01

A Telescience Life Sciences Testbed is being developed. The first phase of this effort consisted of defining the experiments to be performed, investigating the various possible means of communication between KSC and MIT, and developing software and hardware support. The experiments chosen were two vestibular sled experiments: a study of ocular torsion produced by Y axis linear acceleration, based on the Spacelab D-1 072 Vestibular Experiment performed pre- and post-flight at KSC; and an optokinetic nystagmus (OKN)/linear acceleration interaction experiment. These two experiments were meant to simulate actual experiments that might be performed on the Space Station and to be representative of space life sciences experiments in general in their use of crew time and communications resources.

Sled Tests Using the Hybrid III Rail Safety ATD and Workstation Tables for Passenger Trains

DOT National Transportation Integrated Search

2017-08-01

The Hybrid III Rail Safety (H3-RS) anthropomorphic test device (ATD) is a crash test dummy developed in the United Kingdom to evaluate abdomen and lower thorax injuries that occur when passengers impact workstation tables during train accidents. The ...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 adenovirusmore » proteinase, an enzyme necessary for viral replication.« less

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

The ‘W’ Prawn-Trawl with Emphasised Drag-Force Transfer to Its Centre Line to Reduce Overall System Drag

PubMed Central

Balash, Cheslav; Sterling, David; Binns, Jonathan; Thomas, Giles; Bose, Neil

2015-01-01

For prawn trawling systems, drag reduction is a high priority as the trawling process is energy intensive. Large benefits have occurred through the use of multiple-net rigs and thin twine in the netting. An additional positive effect of these successful twine-area reduction strategies is the reduced amount of otter board area required to spread the trawl systems, which leads to further drag reduction. The present work investigated the potential of redirecting the drag-strain within a prawn trawl away from the wings and the otter boards to the centre line of the trawl, where top and bottom tongues have been installed, with an aim to minimise the loading/size of the otter boards required to spread the trawl. In the system containing the new ‘W’ trawl, the drag redirected to the centre-line tongues is transferred forward through a connected sled and towing wires to the trawler. To establish the extent of drag redirection to the centre-line tongues and the relative drag benefits of the new trawl system, conventional and ‘W’ trawls of 3.65 m headline length were tested firstly over a range of spread ratios in the flume tank, and subsequently at optimum spread ratio in the field. The developed ‘W’ trawl effectively directed 64% of netting-drag off the wings and onto the centre tongues, which resulted in drag savings in the field of ∼20% for the associated ‘W’ trawl/otter-board/sled system compared to the traditional trawl/otter-board arrangement in a single trawl or twin rig configuration. Furthermore, based on previously published data, the new trawl when used in a twin rig system is expected to provide approximately 12% drag reduction compared to quad rig. The twin ‘W’ trawl system also has benefits over quad rig in that a reduced number of cod-end/By-catch Reduction Device units need to be installed and attended each tow. PMID:25751251

Top tether effectiveness during side impacts.

PubMed

Majstorovic, Jordan; Bing, Julie; Dahle, Eric; Bolte, John; Kang, Yun-Seok

2018-02-28

Few studies have looked at the effectiveness of the top tether during side impacts. In these studies, limited anthropomorphic test device (ATD) data were collected and/or few side impact scenarios were observed. The goal of this study was to further understand the effects of the top tether on ATD responses and child restraint system (CRS) kinematics during various side impact conditions. A series of high-speed near-side and far-side sled tests were performed using the FMVSS213 side impact sled buck and Q3s ATD. Tests were performed at both 10° and 30° impacts with respect to the pure lateral direction. Two child restraints, CRS A and CRS B, were attached to the bench using flexible lower anchors. Each test scenario was performed with the presence and absence of a top tether. Instrumentation recorded Q3s responses and CRS kinematics, and the identical test scenarios with and without a top tether attachment were compared. For the far-side lateral (10°) and oblique (30°) impacts, top tether attachment increased resultant head accelerations by 8-38% and head injury criterion (HIC 15 ) values by 20-140%. However, the top tether was effective in reducing lateral head excursion by 5-25%. For near-side impacts, the top tether resulted in less than 10% increases in both resultant head acceleration and HIC 15 in the lateral impact direction. For near-side oblique impacts, the top tether increased HIC 15 by 17.3% for CRS A and decreased it by 19.5% for CRS B. However, the injury values determined from both impact conditions were below current injury assessment reference values (IARVs). Additionally, the top tether proved beneficial in preventing forward and lateral CRS rotations. The results show that the effects of the top tether on Q3s responses were dependent on impact type, impact angle, and CRS. Tether attachments that increased head accelerations and HIC 15 values were generally counterbalanced by a reduction in head excursion and CRS rotation compared to

The Effect of Upper Body Mass and Initial Knee Flexion on the Injury Outcome of Post Mortem Human Subject Pedestrian Isolated Legs.

PubMed

Petit, Philippe; Trosseille, Xavier; Dufaure, Nicolas; Dubois, Denis; Potier, Pascal; Vallancien, Guy

2014-11-01

In the ECE 127 Regulation on pedestrian leg protection, as well as in the Euro NCAP test protocol, a legform impactor hits the vehicle at the speed of 40 kph. In these tests, the knee is fully extended and the leg is not coupled to the upper body. However, the typical configuration of a pedestrian impact differs since the knee is flexed during most of the gait cycle and the hip joint applies an unknown force to the femur. This study aimed at investigating the influence of the inertia of the upper body (modelled using an upper body mass fixed at the proximal end of the femur) and the initial knee flexion angle on the lower limb injury outcome. In total, 18 tests were conducted on 18 legs from 9 Post Mortem Human Subjects (PMHS). The principle of these tests was to impact the leg at 40 kph using a sled equipped with 3 crushing steel tubes, the stiffness of which were representative of the front face of a European sedan (bonnet leading edge, bumper and spoiler). The mass of the equipped sled was 74.5 kg. The test matrix was designed to perform 4 tests in 4 configurations combining two upper body masses (either 0 or 3 kg) and two knee angles (0 or 20 degrees) at 40 kph (11 m/s) plus 2 tests at 9 m/s. Autopsies were performed on the lower limbs and an injury assessment was established. The findings of this study were first that the increase of the upper body mass resulted in more severe injuries, second that an initial flexion of the knee, corresponding to its natural position during the gait cycle, decreased the severity of the injuries, and third that based on the injury outcome, a test conducted with no upper body mass and the knee fully extended was as severe as a test conducted with a 3 kg upper body mass and an initial knee flexion of 20°.

Head impact exposure measured in a single youth football team during practice drills.

PubMed

Kelley, Mireille E; Kane, Joeline M; Espeland, Mark A; Miller, Logan E; Powers, Alexander K; Stitzel, Joel D; Urban, Jillian E

2017-11-01

OBJECTIVE This study evaluated the frequency, magnitude, and location of head impacts in practice drills within a youth football team to determine how head impact exposure varies among different types of drills. METHODS On-field head impact data were collected from athletes participating in a youth football team for a single season. Each athlete wore a helmet instrumented with a Head Impact Telemetry (HIT) System head acceleration measurement device during all preseason, regular season, and playoff practices. Video was recorded for all practices, and video analysis was performed to verify head impacts and assign each head impact to a specific drill. Eleven drills were identified: dummy/sled tackling, install, special teams, Oklahoma, one-on-one, open-field tackling, passing, position skill work, multiplayer tackle, scrimmage, and tackling drill stations. Generalized linear models were fitted to log-transformed data, and Wald tests were used to assess differences in head accelerations and impact rates. RESULTS A total of 2125 impacts were measured during 30 contact practices in 9 athletes (mean age 11.1 ± 0.6 years, mean mass 44.9 ± 4.1 kg). Open-field tackling had the highest median and 95th percentile linear accelerations (24.7 g and 97.8 g, respectively) and resulted in significantly higher mean head accelerations than several other drills. The multiplayer tackle drill resulted in the highest head impact frequency, with an average of 0.59 impacts per minute per athlete, but the lowest 95th percentile linear accelerations of all drills. The front of the head was the most common impact location for all drills except dummy/sled tackling. CONCLUSIONS Head impact exposure varies significantly in youth football practice drills, with several drills exposing athletes to high-magnitude and/or high-frequency head impacts. These data suggest that further study of practice drills is an important step in developing evidence-based recommendations for modifying or eliminating

Effects of whole spine alignment patterns on neck responses in rear end impact.

PubMed

Sato, Fusako; Odani, Mamiko; Miyazaki, Yusuke; Yamazaki, Kunio; Östh, Jonas; Svensson, Mats

2017-02-17

The aim of this study was to investigate the whole spine alignment in automotive seated postures for both genders and the effects of the spinal alignment patterns on cervical vertebral motion in rear impact using a human finite element (FE) model. Image data for 8 female and 7 male subjects in a seated posture acquired by an upright open magnetic resonance imaging (MRI) system were utilized. Spinal alignment was determined from the centers of the vertebrae and average spinal alignment patterns for both genders were estimated by multidimensional scaling (MDS). An occupant FE model of female average size (162 cm, 62 kg; the AF 50 size model) was developed by scaling THUMS AF 05. The average spinal alignment pattern for females was implemented in the model, and model validation was made with respect to female volunteer sled test data from rear end impacts. Thereafter, the average spinal alignment pattern for males and representative spinal alignments for all subjects were implemented in the validated female model, and additional FE simulations of the sled test were conducted to investigate effects of spinal alignment patterns on cervical vertebral motion. The estimated average spinal alignment pattern was slight kyphotic, or almost straight cervical and less-kyphotic thoracic spine for the females and lordotic cervical and more pronounced kyphotic thoracic spine for the males. The AF 50 size model with the female average spinal alignment exhibited spine straightening from upper thoracic vertebra level and showed larger intervertebral angular displacements in the cervical spine than the one with the male average spinal alignment. The cervical spine alignment is continuous with the thoracic spine, and a trend of the relationship between cervical spine and thoracic spinal alignment was shown in this study. Simulation results suggested that variations in thoracic spinal alignment had a potential impact on cervical spine motion as well as cervical spinal alignment in rear

WATER VAPOR IN NEARBY INFRARED GALAXIES AS PROBED BY HERSCHEL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang Chentao; Gao Yu; Liu Daizhong

2013-07-10

We report the first systematic study of the submillimeter water vapor rotational emission lines in infrared (IR) galaxies based on the Fourier Transform Spectrometer (FTS) data of Herschel SPIRE. Among the 176 galaxies with publicly available FTS data, 45 have at least one H{sub 2}O emission line detected. The H{sub 2}O line luminosities range from {approx}1 Multiplication-Sign 10{sup 5} L{sub Sun} to {approx}5 Multiplication-Sign 10{sup 7} L{sub Sun} while the total IR luminosities (L{sub IR}) have a similar spread ({approx}1-300 Multiplication-Sign 10{sup 10} L{sub Sun }). In addition, emission lines of H{sub 2}O{sup +} and H{sub 2}{sup 18}O are alsomore » detected. H{sub 2}O is found, for most galaxies, to be the strongest molecular emitter after CO in FTS spectra. The luminosity of the five most important H{sub 2}O lines is near-linearly correlated with L{sub IR}, regardless of whether or not strong active galactic nucleus signature is present. However, the luminosity of H{sub 2}O(2{sub 11}-2{sub 02}) and H{sub 2}O(2{sub 20}-2{sub 11}) appears to increase slightly faster than linear with L{sub IR}. Although the slope turns out to be slightly steeper when z {approx} 2-4 ULIRGs are included, the correlation is still closely linear. We find that L{sub H{sub 2O}}/L{sub IR} decreases with increasing f{sub 25}/f{sub 60}, but see no dependence on f{sub 60}/f{sub 100}, possibly indicating that very warm dust contributes little to the excitation of the submillimeter H{sub 2}O lines. The average spectral line energy distribution (SLED) of the entire sample is consistent with individual SLEDs and the IR pumping plus collisional excitation model, showing that the strongest lines are H{sub 2}O(2{sub 02}-1{sub 11}) and H{sub 2}O(3{sub 21}-3{sub 12}).« less

Using Modeling and Simulation to Complement Testing for Increased Understanding of Weapon Subassembly Response.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wong, Michael K.; Davidson, Megan

As part of Sandia’s nuclear deterrence mission, the B61-12 Life Extension Program (LEP) aims to modernize the aging weapon system. Modernization requires requalification and Sandia is using high performance computing to perform advanced computational simulations to better understand, evaluate, and verify weapon system performance in conjunction with limited physical testing. The Nose Bomb Subassembly (NBSA) of the B61-12 is responsible for producing a fuzing signal upon ground impact. The fuzing signal is dependent upon electromechanical impact sensors producing valid electrical fuzing signals at impact. Computer generated models were used to assess the timing between the impact sensor’s response to themore » deceleration of impact and damage to major components and system subassemblies. The modeling and simulation team worked alongside the physical test team to design a large-scale reverse ballistic test to not only assess system performance, but to also validate their computational models. The reverse ballistic test conducted at Sandia’s sled test facility sent a rocket sled with a representative target into a stationary B61-12 (NBSA) to characterize the nose crush and functional response of NBSA components. Data obtained from data recorders and high-speed photometrics were integrated with previously generated computer models in order to refine and validate the model’s ability to reliably simulate real-world effects. Large-scale tests are impractical to conduct for every single impact scenario. By creating reliable computer models, we can perform simulations that identify trends and produce estimates of outcomes over the entire range of required impact conditions. Sandia’s HPCs enable geometric resolution that was unachievable before, allowing for more fidelity and detail, and creating simulations that can provide insight to support evaluation of requirements and performance margins. As computing resources continue to improve, researchers at Sandia

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

Tilt perception during dynamic linear acceleration.

PubMed

Seidman, S H; Telford, L; Paige, G D

1998-04-01

Head tilt is a rotation of the head relative to gravity, as exemplified by head roll or pitch from the natural upright orientation. Tilt stimulates both the otolith organs, owing to shifts in gravitational orientation, and the semicircular canals in response to head rotation, which in turn drive a variety of behavioral and perceptual responses. Studies of tilt perception typically have not adequately isolated otolith and canal inputs or their dynamic contributions. True tilt cannot readily dissociate otolith from canal influences. Alternatively, centrifugation generates centripetal accelerations that simulate tilt, but still entails a rotatory (canal) stimulus during important periods of the stimulus profiles. We reevaluated the perception of head tilt in humans, but limited the stimulus to linear forces alone, thus isolating the influence of otolith inputs. This was accomplished by employing a centrifugation technique with a variable-radius spinning sled. This allowed us to accelerate the sled to a constant angular velocity (128 degrees/s), with the subject centered, and then apply dynamic centripetal accelerations after all rotatory perceptions were extinguished. These stimuli were presented in the subjects' naso-occipital axis by translating the subjects 50 cm eccentrically either forward or backward. Centripetal accelerations were thus induced (0.25 g), which combined with gravity to yield a dynamically shifting gravitoinertial force simulating pitch-tilt, but without actually rotating the head. A magnitude-estimation task was employed to characterize the dynamic perception of pitch-tilt. Tilt perception responded sluggishly to linear acceleration, typically reaching a peak after 10-30 s. Tilt perception also displayed an adaptation phenomenon. Adaptation was manifested as a per-stimulus decline in perceived tilt during prolonged stimulation and a reversal aftereffect upon return to zero acceleration (i.e., recentering the subject). We conclude that otolith

An energy-absorbing sliding seat for reducing neck injury risks in rear impact--analysis for prototype built.

PubMed

Zhang, Xiaowei; Zhou, Qing

2016-01-01

This study investigated overall performance of an energy-absorbing sliding seat concept for whiplash neck injury prevention. The sliding seat allows its seat pan to slide backward for some distance under certain restraint force to absorb crash energy in rear impacts. A numerical model that consisted of vehicle interior, seat, seat belt, and BioRID II dummy was built in MADYMO to evaluate whiplash neck injury in rear impact. A parametric study of the effects of sliding seat parameters, including position and cushion stiffness of head restraint, seatback cushion stiffness, recliner characteristics, and especially sliding energy-absorbing (EA) restraint force, on neck injury criteria was conducted in order to compare the effectiveness of the sliding seat concept with that of other existing anti-whiplash mechanisms. Optimal sliding seat design configurations in rear crashes of different severities were obtained. A sliding seat prototype with bending of a steel strip as an EA mechanism was fabricated and tested in a sled test environment to validate the concept. The performance of the sliding seat under frontal and rollover impacts was checked to make sure the sliding mechanism did not result in any negative effects. The protective effect of the sliding seat with EA restraint force is comparable to that of head restraint-based and recliner stiffness-based anti-whiplash mechanisms. EA restraint force levels of 3 kN in rear impacts of low and medium severities and 6 kN in impacts of high severity were obtained from optimization. In frontal collision and rollover, compared to the nonsliding seat, the sliding seat does not result in any negative effects on occupant protection. The sled test results of the sliding seat prototype have shown the effectiveness of the concept for reducing neck injury risks. As a countermeasure, the sliding seat with appropriate restraint forces can significantly reduce whiplash neck injury risk in rear impacts of low, medium, and high

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.

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.

Development and performance test of a new high power RF window in S-band PLS-II LINAC

NASA Astrophysics Data System (ADS)

Hwang, Woon-Ha; Joo, Young-Do; Kim, Seung-Hwan; Choi, Jae-Young; Noh, Sung-Ju; Ryu, Ji-Wan; Cho, Young-Ki

2017-12-01

A prototype of RF window was developed in collaboration with the Pohang Accelerator Laboratory (PAL) and domestic companies. High power performance tests of the single RF window were conducted at PAL to verify the operational characteristics for its application in the Pohang Light Source-II (PLS-II) linear accelerator (Linac). The tests were performed in the in-situ facility consisting of a modulator, klystron, waveguide network, vacuum system, cooling system, and RF analyzing equipment. The test results with Stanford linear accelerator energy doubler (SLED) have shown no breakdown up to 75 MW peak power with 4.5 μs RF pulse width at a repetition rate of 10 Hz. The test results with the current operation level of PLS-II Linac confirm that the RF window well satisfies the criteria for PLS-II Linac operation.

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.

Deflection corridors of abdomen and thorax in oblique side impacts using equal stress equal velocity approach: comparison with other normalization methods.

PubMed

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

2014-10-01

The first objective of the study was to determine the thorax and abdomen deflection time corridors using the equal stress equal velocity approach from oblique side impact sled tests with postmortem human surrogates fitted with chestbands. The second purpose of the study was to generate deflection time corridors using impulse momentum methods and determine which of these methods best suits the data. An anthropometry-specific load wall was used. Individual surrogate responses were normalized to standard midsize male anthropometry. Corridors from the equal stress equal velocity approach were very similar to those from impulse momentum methods, thus either method can be used for this data. Present mean and plus/minus one standard deviation abdomen and thorax deflection time corridors can be used to evaluate dummies and validate complex human body finite element models.

Perception of linear acceleration in weightlessness

NASA Technical Reports Server (NTRS)

Arrott, Anthony P.; Young, Laurence R.; Merfeld, Daniel M.

1991-01-01

Tests of the perception and use of linear acceleration sensory information were performed on the science crews of the Spacelab 1 (SL-1) and D-1 missions using linear 'sleds' in-flight (D-1) and pre-post flight. The time delay between the acceleration step stimulus and the subjective response was consistently reduced during weightlessness, but was neither statistically significant nor of functional importance. Increased variability of responses when going from one environment to the other was apparent from measurements on the first day of the mission and in the first days post-flight. Subjective reports of perceived motion during sinusoidal oscillation in weightlessness were qualitatively similar to reports on earth. In a closed-loop motion nulling task, enhanced performance was observed post-flight in all crewmembers tested in the Y or Z axes.

Perception of linear acceleration in weightlessness

NASA Technical Reports Server (NTRS)

Arrott, A. P.; Young, L. R.; Merfeld, D. M.

1990-01-01

Tests of the perception and use of linear acceleration sensory information were performed on the science crews of the Spacelab 1 (SL-1) and D-1 missions using linear "sleds" in-flight (D-1) and pre-post flight. The time delay between the acceleration step stimulus and the subjective response was consistently reduced during weightlessness, but was neither statistically significant nor of functional importance. Increased variability of responses when going from one environment to the other was apparent from measurements on the first day of the mission and in the first days post-flight. Subjective reports of perceived motion during sinusoidal oscillation in weightlessness were qualitatively similar to reports on earth. In a closed-loop motion nulling task, enhanced performance was observed post-flight in all crewmembers tested in the Y or Z axes.

Thresholds for the perception of whole-body linear sinusoidal motion in the horizontal plane

NASA Technical Reports Server (NTRS)

Mah, Robert W.; Young, Laurence R.; Steele, Charles R.; Schubert, Earl D.

1989-01-01

An improved linear sled has been developed to provide precise motion stimuli without generating perceptible extraneous motion cues (a noiseless environment). A modified adaptive forced-choice method was employed to determine perceptual thresholds to whole-body linear sinusoidal motion in 25 subjects. Thresholds for the detection of movement in the horizontal plane were found to be lower than those reported previously. At frequencies of 0.2 to 0.5 Hz, thresholds were shown to be independent of frequency, while at frequencies of 1.0 to 3.0 Hz, thresholds showed a decreasing sensitivity with increasing frequency, indicating that the perceptual process is not sensitive to the rate change of acceleration of the motion stimulus. The results suggest that the perception of motion behaves as an integrating accelerometer with a bandwidth of at least 3 Hz.

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.

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

Comparison of interior crashworthiness observed in passenger train accidents and 8G dynamic seat sled tests

DOT National Transportation Integrated Search

2012-04-17

The Office of Research and Development of the Federal Railroad Administration conducts engineering research to address protection of passengers and crew during train accidents. This research includes accident investigations and dynamic seat testing t...

Evaluation of wheelchair drop seat crashworthiness.

PubMed

Bertocci, G; Ha, D; van Roosmalen, L; Karg, P; Deemer, E

2001-05-01

Wheelchair seating crash performance is critical to protecting wheelchair users who remain seated in their wheelchairs during transportation. Relying upon computer simulation and sled testing seat loads associated with a 20 g/48 kph (20 g/30 mph) frontal impact and 50th percentile male occupant were estimated to develop test criteria. Using a static test setup we evaluated the performance of various types of commercially available drop seats against the loading test criteria. Five different types of drop seats (two specimens each) constructed of various materials (i.e. plastics, plywood, metal) were evaluated. Two types of drop seats (three of the total 10 specimens) met the 16650 N (3750 lb) frontal impact test criteria. While additional validation of the test protocol is necessary, this study suggests that some drop seat designs may be incapable of withstanding crash level loads.

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.

STS-42 MS Hilmers and Payload Specialist Merbold use IML-1 visual stimulator

NASA Image and Video Library

1992-01-30

STS042-203-024 (22-30 Jan. 1992) --- Astronaut David C. Hilmers (right), STS-42 mission specialist, assists European Space Agency (ESA) payload specialist Ulf Merbold with the visual stimulator experiment on the Space Shuttle Discovery's middeck. This particular test is part of an ongoing study of the Space Adaptation Syndrome (SAS). Seated in a stationary mini-sled, Merbold (or any other subject for this test) stares at an umbrella-shaped rotating dome with a pattern of colored dots on its interior. While observing the rotating dome, the subject turns a knob to indicate his perception of body rotation. The strength of circular vection is calculated by comparing the signals from the dome and the knob. The greater the false sense of circular vection, the more the subject is relying on visual information instead of otolith information.

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

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

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

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

On the meaning of sports: cross cultural observations of super stress.

PubMed

Pierce, C M; Stillner, V; Popkin, M

1982-03-01

The definition of sports medicine indicates the possible therapeutic and research importance of games in the work of social scientists and clinicians. A cross-cultural comparison of super stressful competitions provides one insight into the importance of games in human societies. Fourteen such comparisons are made between Indians in Mexico who run 250-mile foot races and Americans in Alaska who conduct 1049-mile dog sled races. It is concluded that sports can help understand how a society defines itself and regulates violence. Games may be an essential "human-specific' need which provide entertainment, retain survival skills, ameliorate existential anxiety and promote religious and/or secular socialization. In this study, humans seem willing, if not insistent, to deploy considerable resources of time and material to sustain competitions among their own species, as well as between and with other species. A "sports history' is important for all individuals.

Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft. Volume 3: Data from crew module testing

NASA Technical Reports Server (NTRS)

Shane, S. J.

1985-01-01

Over the past years, several papers and reports have documented the unacceptably high injury rate during the escape sequence (including the ejection and ground impact) of the crew module for F/FB-111 aircraft. This report documents a program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats. 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 werre conducted. The vertical drop tests were used to obtain comparative data between the energy absorbing and operational seats.

Thoracic Injury Risk Curves for Rib Deflections of the SID-IIs Build Level D.

PubMed

Irwin, Annette L; Crawford, Greg; Gorman, David; Wang, Sikui; Mertz, Harold J

2016-11-01

Injury risk curves for SID-IIs thorax and abdomen rib deflections proposed for future NCAP side impact evaluations were developed from tests conducted with the SID-IIs FRG. Since the floating rib guide is known to reduce the magnitude of the peak rib deflections, injury risk curves developed from SID-IIs FRG data are not appropriate for use with SID-IIs build level D. PMHS injury data from three series of sled tests and one series of whole-body drop tests are paired with thoracic rib deflections from equivalent tests with SID-IIs build level D. Where possible, the rib deflections of SID-IIs build level D were scaled to adjust for differences in impact velocity between the PMHS and SID-IIs tests. Injury risk curves developed by the Mertz-Weber modified median rank method are presented and compared to risk curves developed by other parametric and non-parametric methods.

rf design of a pulse compressor with correction cavity chain for klystron-based compact linear collider

NASA Astrophysics Data System (ADS)

Wang, Ping; Zha, Hao; Syratchev, Igor; Shi, Jiaru; Chen, Huaibi

2017-11-01

We present an X-band high-power pulse compression system for a klystron-based compact linear collider. In this system design, one rf power unit comprises two klystrons, a correction cavity chain, and two SLAC Energy Doubler (SLED)-type X-band pulse compressors (SLEDX). An rf pulse passes the correction cavity chain, by which the pulse shape is modified. The rf pulse is then equally split into two ways, each deploying a SLEDX to compress the rf power. Each SLEDX produces a short pulse with a length of 244 ns and a peak power of 217 MW to power four accelerating structures. With the help of phase-to-amplitude modulation, the pulse has a dedicated shape to compensate for the beam loading effect in accelerating structures. The layout of this system and the rf design and parameters of the new pulse compressor are described in this work.

The Influence of Body Mass on Physical Fitness Test Performance in Male Firefighter Applicants.

PubMed

Phillips, Devin B; Scarlett, Michael P; Petersen, Stewart R

2017-11-01

The influence of body mass on test performance was investigated in 414 male firefighter applicants who completed a maximal treadmill test and five task-simulation tests while dressed in fire protective ensemble. Subjects were assigned to six mass categories from less than 70 kg to more than 110 kg, in 10 kg increments (n = 69 in each). Treadmill performance was lower (P < 0.05) in the two heaviest groups. Charged hose advance time was slower in the two lightest groups. The lightest group had slower times for weighted sled pull, forcible entry, and victim rescue tests. The heaviest group was slower on the ladder climb test. Lighter subjects had a small advantage in endurance-oriented tests while higher mass appeared to improve performance slightly in strength-oriented tests. However, mass explained only 4% to 19% of the variance in performance.

Technique for positioning hologram for balancing large data capacity with fast readout

NASA Astrophysics Data System (ADS)

Shimada, Ken-ichi; Hosaka, Makoto; Yamazaki, Kazuyoshi; Onoe, Shinsuke; Ide, Tatsuro

2017-09-01

The technical difficulty of balancing large data capacity with a high data transfer rate in holographic data storage systems (HDSSs) is significantly high because of tight tolerances for physical perturbation. From a system margin perspective in terabyte-class HDSSs, the positioning error of a holographic disc should be within about 10 µm to ensure high readout quality. Furthermore, fine control of the positioning should be accomplished within a time frame of about 10 ms for a high data transfer rate of the Gbps class, while a conventional method based on servo control of spindle or sled motors can rarely satisfy the requirement. In this study, a new compensation method for the effect of positioning error, which precisely controls the positioning of a Nyquist aperture instead of a holographic disc, has been developed. The method relaxes the markedly low positional tolerance of a holographic disc. Moreover, owing to the markedly light weight of the aperture, positioning control within the required time frame becomes feasible.

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.

Fatal dog attacks in Canada, 1990–2007

PubMed Central

Raghavan, Malathi

2008-01-01

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. PMID:18624067

The effects of temperature dependent recombination rates on performance of InGaN/GaN blue superluminescent light emitting diodes

NASA Astrophysics Data System (ADS)

Moslehi Milani, N.; Mohadesi, V.; Asgari, A.

2015-07-01

The effects of temperature dependent radiative and nonradiative recombination (Shockley-Read-Hall, spontaneous radiative, and Auger coefficients) on the spectral and power characteristics of a blue multiple quantum well (MQW) superluminescent light emitting diode (SLD or SLED) have been studied. The study is based on the rate equations model, where three rate equations corresponding to MQW active region, separate confinement heterostructure (SCH) layer, and spectral density of optical power are solved self-consistently with no k-selection energy dependent gain and quasi-Fermi level functions at steady state. We have taken into account the temperature effects on Shockley-Read-Hall (SRH), spontaneous radiative, and Auger recombination in the rate equations and have investigated the effects of temperature rising from 300 K to 375 K at a fixed current density. We examine this procedure for a moderate current density and interpret the spectral radiation power and light output power diagrams. The investigation reveals that the main loss due to temperature is related to Auger coefficient.

Ferroelectric switch for a high-power Ka-band active pulse compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 couldmore » 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.« less

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.

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.

Ultra-Wideband Radar Measurements of Thickness of Snow Over Sea Ice

NASA Technical Reports Server (NTRS)

Kanagaratnam, P.; Markus, T.; Lytle, V.; Heavey, B.; Jansen, P.; Prescott, G.; Gogineni, S.

2007-01-01

An accurate knowledge of snow thickness and its variability over sea ice is crucial for determining the overall polar heat and freshwater budget, which influences the global climate. Recently, algorithms have been developed to extract snow thicknesses from passive microwave satellite data. However, validation of these data over the large footprint of the passive microwave sensor has been a challenge. The only method used thus far has been with meter sticks during ship cruises. To address this problem, we developed an ultra wideband frequency-modulated continuous-wave (FM-CW) radar to measure snow thickness over sea ice. We made snow-thickness measurements over Antarctic sea ice by operating the radar from a sled during September and October, 2003. We performed radar measurements over 11 stations with varying snow thickness between 4 and 85 cm. We observed excellent agreement between radar estimates of snow thickness with physical measurements, achieving a correlation coefficient of 0.95 and a vertical resolution of about 3 cm.

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/.

Biomechanics of liver injury by steering wheel loading.

PubMed

Lau, I V; Horsch, J D; Viano, D C; Andrzejak, D V

1987-03-01

Abdominal injury induced by steering wheel contact at a velocity of 32 km/hr was investigated using anesthetized swine as the surrogate on a Hyge sled. The lower rim of the wheel was positioned 5 cm below the xyphoid. By varying wheel stiffness, wheel orientation, and column angle, resultant abdominal injury ranged from fatal or critical to minor or none. Wheel stiffness was found to be the primary determinant of abdominal injury severity. The mechanism of abdominal injury was identified to be the rim impacting the abdomen and exceeding a combined velocity and compression sensitive tolerance limit. Abdominal injury occurred within the initial 15 ms of wheel contact before whole body movement of the surrogate of column compression, which were initiated by hub contact with the thorax. The severity of abdominal injury correlated with the peak viscous response which can be represented by the product of the instantaneous velocity of abdominal deformation and abdominal compression. It did not correlate with spinal acceleration.

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.

Automated recognition of rear seat occupants' head position using Kinect™ 3D point cloud.

PubMed

Loeb, Helen; Kim, Jinyong; Arbogast, Kristy; Kuo, Jonny; Koppel, Sjaan; Cross, Suzanne; Charlton, Judith

2017-12-01

Child occupant safety in motor-vehicle crashes is evaluated using Anthropomorphic Test Devices (ATD) seated in optimal positions. However, child occupants often assume suboptimal positions during real-world driving trips. Head impact to the seat back has been identified as one important injury causation scenario for seat belt restrained, head-injured children (Bohman et al., 2011). There is therefore a need to understand the interaction of children with the Child Restraint System to optimize protection. Naturalistic driving studies (NDS) will improve understanding of out-of-position (OOP) trends. To quantify OOP positions, an NDS was conducted. Families used a study vehicle for two weeks during their everyday driving trips. The positions of rear-seated child occupants, representing 22 families, were evaluated. The study vehicle - instrumented with data acquisition systems, including Microsoft Kinect™ V1 - recorded rear seat occupants in 1120 driving 26 trips. Three novel analytical methods were used to analyze data. To assess skeletal tracking accuracy, analysts recorded occurrences where Kinect™ exhibited invalid head recognition among a randomly-selected subset (81 trips). Errors included incorrect target detection (e.g., vehicle headrest) or environmental interference (e.g., sunlight). When head data was present, Kinect™ was correct 41% of the time; two other algorithms - filtering for extreme motion, and background subtraction/head-based depth detection are described in this paper and preliminary results are presented. Accuracy estimates were not possible because of their experimental nature and the difficulty to use a ground truth for this large database. This NDS tested methods to quantify the frequency and magnitude of head positions for rear-seated child occupants utilizing Kinect™ motion-tracking. This study's results informed recent ATD sled tests that replicated observed positions (most common and most extreme), and assessed the validity of child

Optimization of vehicle deceleration to reduce occupant injury risks in frontal impact.

PubMed

Mizuno, Koji; Itakura, Takuya; Hirabayashi, Satoko; Tanaka, Eiichi; Ito, Daisuke

2014-01-01

In vehicle frontal impacts, vehicle acceleration has a large effect on occupant loadings and injury risks. In this research, an optimal vehicle crash pulse was determined systematically to reduce injury measures of rear seat occupants by using mathematical simulations. The vehicle crash pulse was optimized based on a vehicle deceleration-deformation diagram under the conditions that the initial velocity and the maximum vehicle deformation were constant. Initially, a spring-mass model was used to understand the fundamental parameters for optimization. In order to investigate the optimization under a more realistic situation, the vehicle crash pulse was also optimized using a multibody model of a Hybrid III dummy seated in the rear seat for the objective functions of chest acceleration and chest deflection. A sled test using a Hybrid III dummy was carried out to confirm the simulation results. Finally, the optimal crash pulses determined from the multibody simulation were applied to a human finite element (FE) model. The optimized crash pulse to minimize the occupant deceleration had a concave shape: a high deceleration in the initial phase, low in the middle phase, and high again in the final phase. This crash pulse shape depended on the occupant restraint stiffness. The optimized crash pulse determined from the multibody simulation was comparable to that from the spring-mass model. From the sled test, it was demonstrated that the optimized crash pulse was effective for the reduction of chest acceleration. The crash pulse was also optimized for the objective function of chest deflection. The optimized crash pulse in the final phase was lower than that obtained for the minimization of chest acceleration. In the FE analysis of the human FE model, the optimized pulse for the objective function of the Hybrid III chest deflection was effective in reducing rib fracture risks. The optimized crash pulse has a concave shape and is dependent on the occupant restraint

Neck forces and moments and head accelerations in side impact.

PubMed

Yoganandan, Narayan; Pintar, Frank A; Maiman, Dennis J; Philippens, Mat; Wismans, Jac

2009-03-01

Although side-impact sled studies have investigated chest, abdomen, and pelvic injury mechanics, determination of head accelerations and the associated neck forces and moments is very limited. The purpose of the present study was therefore to determine the temporal forces and moments at the upper neck region and head angular accelerations and angular velocities using postmortem human subjects (PMHS). Anthropometric data and X-rays were obtained, and the specimens were positioned upright on a custom-designed seat, rigidly fixed to the platform of the sled. PMHS were seated facing forward with the Frankfort plane horizontal, and legs were stretched parallel to the mid-sagittal plane. The normal curvature and alignment of the dorsal spine were maintained without initial torso rotation. A pyramid-shaped nine-accelerometer package was secured to the parietal-temporal region of the head. The test matrix consisted of groups A and B, representing the fully restrained torso condition, and groups C and D, representing the three-point belt-restrained torso condition. The change in velocity was 12.4 m/s for groups A and C, 17.9 m/s for group B, and 8.7 m/s for group D tests. Two specimens were tested in each group. Injuries were scored based on the Abbreviated Injury Scale. The head mass, center of gravity, and moment of inertia were determined for each specimen. Head accelerations and upper neck forces and moments were determined before head contact. Neck forces and moments and head angular accelerations and angular velocities are presented on a specimen-by-specimen basis. In addition, a summary of peak magnitudes of biomechanical data is provided because of their potential in serving as injury reference values characterizing head-neck biomechanics in side impacts. Though no skull fractures occurred, AIS 0 to 3 neck traumas were dependent on the impact velocity and restraint condition. Because specimen-specific head center of gravity and mass moment of inertia were determined

Warm and cold molecular gas conditions modeled in 87 galaxies observed by the Herschel SPIRE FTS

NASA Astrophysics Data System (ADS)

Kamenetzky, Julia; Rangwala, Naseem; Glenn, Jason

2018-01-01

Molecular gas is the raw material for star formation, and like the interstellar medium (ISM) in general, it can exist in regions of higher and lower excitation. Rotational transitions of the CO molecule are bright and sensitive to cold molecular gas. While the majority of the molecular gas exists in the very cold component traced by CO J=1-0, the higher-J lines trace the highly excited gas that may be more indicative of star formation processes. The atmosphere is opaque to these lines, but the launch of the Herschel Space Observatory made them accessible for study of Galactic and extragalactic sources. We have conducted two-component, non-local thermodynamic equilibrium (non-LTE) modeling of the CO lines from J=1‑0 through J=13‑12 in 87 galaxies observed by the Herschel SPIRE Fourier Transform Spectrometer (FTS). We used the nested sampling algorithm Multinest to compare the measured CO spectral line energy distributions (SLEDs) to the ones produced by a custom version of the non-LTE code RADEX. This allowed us to fully examine the degeneracies in parameter space for kinetic temperature, molecular gas density, CO column density, and area filling factor.Here we discuss the major findings of our study, as well as the important implications of two-component molecular gas modeling. The average pressure of the warm gas is slightly correlated with galaxy LFIR, but that of the cold gas is not. A high-J (such as J=11-10) to J=1-0 line ratio is diagnostic of warm component pressure. We find a very large spread in our derived values of "alpha-CO," with no discernable trend with LFIR, and average molecular gas depletion times that decrease with LFIR. If only a few molecular lines are available in a galaxy's SLED, the limited ability to model only one component will change the results. A one-component fit often underestimates the flux of carbon monoxide (CO) J=1‑0 and the mass. If low-J lines are not included, mass is underestimated by an order of magnitude. Even when

Proposed test method for and evaluation of wheelchair seating system (WCSS) crashworthiness.

PubMed

van Roosmalen, L; Bertocci, G; Ha, D R; Karg, P; Szobota, S

2000-01-01

Safety of motor vehicle seats is of great importance in providing crash protection to the occupant. An increasing number of wheelchair users use their wheelchairs as motor vehicle seats when traveling. A voluntary standard requires that compliant wheelchairs be dynamically sled impact tested. However, testing to evaluate the crashworthiness of add-on wheelchair seating systems (WCSS) independent of their wheelchair frame is not addressed by this standard. To address this need, this study developed a method to evaluate the crash-worthiness of WCSS with independent frames. Federal Motor Vehicle Safety Standards (FMVSS) 207 test protocols, used to test the strength of motor vehicle seats, were modified and used to test the strength of three WCSS. Forward and rearward loads were applied at the WCSS center of gravity (CGSS), and a moment was applied at the uppermost point of the seat back. Each of the three tested WCSS met the strength requirements of FMVSS 207. Wheelchair seat-back stiffness was also investigated and compared to motor vehicle seat-back stiffness.

Joint helmet-mounted cueing system (JHMCS) helmet qualification testing requirements

NASA Astrophysics Data System (ADS)

Orf, Garry W.

1998-08-01

The Joint Helmet-Mounted Cueing System (JHMCS) program will provide capability to cue high off-boresight (HOBS) weapons to the operator's line of sight and to confirm weapon sensor LOS for the US Air Force and US Navy (USN) aircrew. This capability will ensure the USAF and USN pilots a first shot opportunity. The JHMCS incorporates an ejection-compatible helmet-mounted display system that will be installed on F- 15, F-16, F/A-18, and F-22 aircraft. The JHMCS includes a flight helmet with display optics, miniature cathode ray tube, magnetic receiver unit, miniature camera, automatic brightness control sensor, and microcontroller. The flight helmet for JHMCS is based on the new lightweight HGU-55A/P. This paper describes the requirements for the helmet qualification tests including: windblast, ejection tower, hanging harness, centrifuge, mass properties, energy attenuation and penetration resistance, noise attenuation, visor characteristics, compatibility demonstration, sled/in- flight ejection, water survival, standard conditions and environment. The test objective, success criteria, equipment configuration, and data collection requirements for each test is discussed.

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.

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.

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.

Factors Influencing Occupant-To-Seat Belt Interaction in Far-Side Crashes

PubMed Central

Douglas, C.A.; Fildes, B.N.; Gibson, T.J.; Boström, O.; Pintar, F.A.

2007-01-01

Seat belt interaction with a far-side occupant’s shoulder and thorax is critical to governing excursion towards the struck-side of the vehicle in side impact. In this study, occupant-to-belt interaction was simulated using a modified MADYMO human model and finite element belts. Quasi-static tests with volunteers and dynamic sled tests with PMHS and WorldSID were used for model validation and comparison. Parameter studies were then undertaken to quantify the effect of impact direction, seat belt geometry and pretension on occupant-to-seat belt interaction. Results suggest that lowering the D-ring and increasing pretension reduces the likelihood of the belt slipping off the shoulder. Anthropometry was also shown to influence restraint provided by the shoulder belt. Furthermore, the belt may slip off the occupant’s shoulder at impact angles greater than 40 degrees from frontal when no pretension is used. However, the addition of pretension allowed the shoulder to engage the belt in all impacts from 30 to 90 degrees. PMID:18184500

Further observations on rangiferine brucellosis in Alaskan carnivores.

PubMed

Neiland, K A

1975-01-01

Antibodies against rangiferine brucellosis, Brucella suis type 4, are commonly found in the serum of various domestic and wild alaskian carnivores which feed on caribou, Rangifer tarandus granti, arctic Alaska. Sled dogs from five native villages on the range of the Artic caribou herd, but not from two villages on the the range of the Porcupine caribou herd, are commonly infected. Wolves (Canis lupus) and red foxes (Vulpes fulva) are less commonly infected. About 90% of the grizzly bears (Ursus arctos horribilis) associated with the Artic caribou herd and 30% of those associated with the porcupine caribou herd show serologic signs of exposure to Brucella, presumalby the enzootic strain present in Alaska caribou. This is the first evidence of natural Brucella infection in bears. It is concluded that infection of predators by enzootic strains of Brucella present in prey species (e.g., ruminants) is common to many areas of the world. Evidence from the literature and unpublished experimental data suggest that such infections may intefere with reproduction in wild species, but additional study is needed to clearly resolve this question.

Massive naproxen overdose with serial serum levels.

PubMed

Al-Abri, Suad A; Anderson, Ilene B; Pedram, Fatehi; Colby, Jennifer M; Olson, Kent R

2015-03-01

Massive naproxen overdose is not commonly reported. Severe metabolic acidosis and seizure have been described, but the use of renal replacement therapy has not been studied in the context of overdose. A 28-year-old man ingested 70 g of naproxen along with an unknown amount of alcohol in a suicidal attempt. On examination in the emergency department 90 min later, he was drowsy but had normal vital signs apart from sinus tachycardia. Serum naproxen level 90 min after ingestion was 1,580 mg/L (therapeutic range 25-75 mg/L). He developed metabolic acidosis requiring renal replacement therapy using sustained low efficiency dialysis (SLED) and continuous venovenous hemofiltration (CVVH) and had recurrent seizure activity requiring intubation within 4 h from ingestion. He recovered after 48 h. Massive naproxen overdose can present with serious toxicity including seizures, altered mental status, and metabolic acidosis. Hemodialysis and renal replacement therapy may correct the acid base disturbance and provide support in cases of renal impairment in context of naproxen overdose, but further studies are needed to determine the extraction of naproxen.

[CI] and CO in local galaxies from the Beyond the Peak Project

NASA Astrophysics Data System (ADS)

Crocker, Alison F.; Pellegrini, E. W.; Smith, J. T.; Beyond The Peak Team

2014-01-01

From simple plane-parallel photodissociation region (PDR) models, neutral carbon ([CI]) is predicted to exist in a thin layer between C+ and CO on the surface of molecular clouds (e.g. (Hollenbach & Tielens 1999, Kaufman et al. 1999). However, observations of the Milky Way and the Magellanic Clouds indicate that [CI] may instead be a better tracer of the entire cold gas reservoir, often very well correlated with emission from 12CO(1-0) or 13CO(1-0) (e.g. Keene et al. 1996, Bolatto et al. 2000, Shimajiri et al. 2013). Here, we present the observed [CI] fluxes from the Beyond the Peak sample of 22 nearby galaxies observed with the Herschel FTS spectrometer. We first attempt to model all CO transitions and the [CI] lines as a single plane-parallel PDR, but this fails in all cases. Instead, a two-component PDR model is able to fit the CO SLED of nearly all galaxies. We investigate correlations of the [CI] fluxes and line ratio with properties of the cooler component determined from the PDR fits.

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.

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.

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

Evaluation of pediatric ATD biofidelity as compared to child volunteers in low-speed far-side oblique and lateral impacts.

PubMed

Seacrist, Thomas; Locey, Caitlin M; Mathews, Emily A; Jones, Dakota L; Balasubramanian, Sriram; Maltese, Matthew R; Arbogast, Kristy B

2014-01-01

Motor vehicle crashes are a leading cause of injury and mortality for children. Mitigation of these injuries requires biofidelic anthropomorphic test devices (ATDs) to design and evaluate automotive safety systems. Effective countermeasures exist for frontal and near-side impacts but are limited for far-side impacts. Consequently, far-side impacts represent increased injury and mortality rates compared to frontal impacts. Thus, the objective of this study was to evaluate the biofidelity of the Hybrid III and Q-series pediatric ATDs in low-speed far-side impacts, with and without shoulder belt pretightening. Low-speed (2 g) far-side oblique (60°) and lateral (90°) sled tests were conducted using the Hybrid III and Q-series 6- and 10-year-old ATDs. ATDs were restrained by a lap and shoulder belt equipped with a precrash belt pretightener. Photoreflective targets were attached to the head, spine, shoulders, and sternum. ATDs were exposed to 8 low-speed sled tests: 2 oblique nontightened, 2 oblique pretightened, 2 lateral nontightened, 2 lateral pretightened. ATDs were compared with previously collected 9- to 11-year-old (n=10) volunteer data and newly collected 6- to 8-year-old volunteer data (n=7) tested with similar methods. Kinematic data were collected from a 3D target tracking system. Metrics of comparison included excursion, seat belt and seat pan reaction loads, belt-to-torso angle, and shoulder belt slip-out. The ATDs exhibited increased lateral excursion of the head top, C4, and T1 as well as increased downward excursion of the head top compared to the volunteers. Volunteers exhibited greater forward excursion than the ATDs in oblique nontightened impacts. These kinematics correspond to increased shoulder belt slip-out for the ATDs in oblique tests (ATDs=90%; volunteers=36%). Contrarily, similar shoulder belt slip-out was observed between ATDs and volunteers in lateral impacts (ATDs=80%; volunteers=78%). In pretightened impacts, the ATDs exhibited reduced

Tectonics of short-offset, slow-slipping transform zones in the FAMOUS area, Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Goud, Margaret R.; Karson, Jeffrey A.

1985-12-01

ANGUS photographs and ALVIN observational data from Fracture Zones A and B on the Mid-Atlantic Ridge near 37°N were examined for structural and sedimentological indications of the area's tectonics. Both transform fault zones are characterized by volcanic rubble, breccias, chalks, and undisturbed sediments typical of slow-slipping transforms. The photographic data consist of 16 camera-sled traverses from the FAMOUS Expedition using the ANGUS deep-towed camera system. These data cover several different morphotectonic provinces along the strike of both slow-slipping (2 cm yr-1) fracture zones. ALVIN data come from two dives in the central part of Fracture Zone B. The two fracture zones differ in their distribution of fractured and sheared chalks which indicate regions of strike-slip deformation along the transform. Evidence of shearing is confined to a very narrow region in the center of FZ A, whereas the zone of shear deformation is as much as 6 km wide across FZ B. Other differences include the morphology and depth of the transform valleys and their contiguous nodal basins and the extent of exposures of fresh-looking volcanic ridges in the nodal basin.

Brain Injury Differences in Frontal Impact Crash Using Different Simulation Strategies

PubMed Central

Ma, Chunsheng; Shen, Ming; Li, Peiyu; Zhang, Jinhuan

2015-01-01

In the real world crashes, brain injury is one of the leading causes of deaths. Using isolated human head finite element (FE) model to study the brain injury patterns and metrics has been a simplified methodology widely adopted, since it costs significantly lower computation resources than a whole human body model does. However, the degree of precision of this simplification remains questionable. This study compared these two kinds of methods: (1) using a whole human body model carried on the sled model and (2) using an isolated head model with prescribed head motions, to study the brain injury. The distribution of the von Mises stress (VMS), maximum principal strain (MPS), and cumulative strain damage measure (CSDM) was used to compare the two methods. The results showed that the VMS of brain mainly concentrated at the lower cerebrum and occipitotemporal region close to the cerebellum. The isolated head modelling strategy predicted higher levels of MPS and CSDM 5%, while the difference is small in CSDM 10% comparison. It suggests that isolated head model may not equivalently reflect the strain levels below the 10% compared to the whole human body model. PMID:26495029

Windfield and trajectory models for tornado-propelled objects. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redmann, G.H.; Radbill, J.R.; Marte, J.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 ofmore » 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.« less

Crashworthiness of Aluminium Tubes; Part 2: Improvement of Hydroforming Operation to Increase Absorption Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

D'Amours, Guillaume; Rahem, Ahmed; Mayer, Robert

2007-05-17

The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments onmore » hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.« less

Temporal changes in deep-sea sponge populations are correlated to changes in surface climate and food supply

NASA Astrophysics Data System (ADS)

Kahn, Amanda S.; Ruhl, Henry A.; Smith, Kenneth L.

2012-12-01

Density and average size of two species of abyssal sponges were analyzed at Station M (∼4100 m depth) over an 18-year time-series (1989-2006) using camera sled transects. Both sponge taxa share a similar plate-like morphology despite being within different families, and both showed similar variations in density and average body size over time, suggesting that the same factors may control the demographics of both species. Peaks in significant cross correlations between increases in particulate organic carbon flux and corresponding increases in sponge density occurred with a time lag of 13 months. Sponge density also fluctuated with changes in two climate indices: the NOI with a time lag of 18 months and NPGO with a time lag of 15 months. The results support previous suggestions that increased particulate organic carbon flux may induce recruitment or regeneration in deep-sea sponges. It is unknown whether the appearance of young individuals results from recruitment, regeneration, or both, but the population responses to seasonal and inter-annual changes in food supply demonstrate that sponge populations are dynamic and are capable of responding to inter-annual changes despite being sessile and presumably slow-growing.

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.

Crashworthiness of Aluminium Tubes; Part 2: Improvement of Hydroforming Operation to Increase Absorption Energy

NASA Astrophysics Data System (ADS)

D'Amours, Guillaume; Rahem, Ahmed; Mayer, Robert; Williams, Bruce; Worswick, Michael

2007-05-01

The motivation to reduce overall vehicle weight within the automotive sector drives the substitution of lightweight materials such as aluminium alloys for structural components. Such a substitution requires a significant amount of development to manufacture structurally parts such that the energy absorption characteristics are not sacrificed in the event of crash. The effects of the manufacturing processes on the crash performance of automotive structural components must be better understood to ensure improved crashworthiness. This paper presents results of an experimental and numerical investigation of the crash response and energy absorption properties of impacted hydroformed aluminium alloy tubes. Crash experiments on hydroformed tubes were performed using a deceleration sled test at the General Motors Technical Center. Results from axial crush testing showed that an important parameter that influences the energy absorption characteristics during crash was the thickness reduction caused by circumferential expansion of the tube during hydroforming. It was found that that the energy absorption decreased as the corner radius decreased, which results because of increased thinning. Sensitivity studies of end feeding parameters, such as end feed level and profile, were carried out to evaluate their impact on the energy absorption of the aluminium tubes.

Dorsal light response and changes of its responses under varying acceleration conditions

NASA Astrophysics Data System (ADS)

Watanabe, S.; Takabayashi, A.; Takagi, S.; von Baumgarten, R.; Wetzig, J.

In order to improve our understanding about functions of the gravity sensors, we have conducted four experiments in goldfish: 1) To define the effect of visual information influx on the static labyrinthine response, the dorsal light response (DLR) which had been proposed by von Holst as a model for postural adjustment in fish was reexamined with a newly designed, rotatory illumination device. The fish responded to illumination from the upper half of the visual field and a narrow range around 180 degrees of the lower half visual field. The maximal tilting angle of normal fish was about 40 degrees under horizontal illumination. 2) Under the changes of the gravito-inertial force level produced by a linear sled, the threshold of the gravity sensors was determined from postural adjustment responses. 3) Under hypogravic conditions during the parabolic flight of an airplane, the light-dependent behavior was investigated in intact and labyrinthectomized goldfish. 4) As one of the most likely candidates of the neural centers for the DLR, the valvula cerebelli, which receives its visual information not through the optic tectum but through the pretectal areas, is confirmed by the brain lesion experiments.

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.

Adverse fetal outcome in road accidents: Injury mechanism study and injury criteria development in a pregnant woman finite element model.

PubMed

Auriault, F; Thollon, L; Pérès, J; Behr, M

2016-12-01

This study documents the development of adverse fetal outcome predictors dedicated to the analysis of road accidents involving pregnant women. To do so, a pre-existing whole body finite element model representative of a 50th percentile 26 weeks pregnant woman was used. A total of 8 accident scenarios were simulated with the model positioned on a sled. Each of these scenarios was associated to a risk of adverse fetal outcome based on results from real car crash investigations involving pregnant women from the literature. The use of airbags and accidents involving unbelted occupants were not considered in this study. Several adverse fetal outcome potential predictors were then evaluated with regard to their correlation to this risk of fetal injuries. Three predictors appeared strongly correlated to the risk of adverse fetal outcome: (1) the intra uterine pressure at the placenta fetal side area (r=0.92), (2) the fetal head acceleration (HIC) (r=0.99) and (3) area of utero-placental interface over a strain threshold (r=0.90). Finally, sensitivity analysis against slight variations of the simulation parameters was performed and assess robustness of these criteria. Copyright © 2016 Elsevier Ltd. All rights reserved.

Loaded delay lines for future RF pulse compression systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, R.M.; Wilson, P.B.; Kroll, N.M.

1995-05-01

The peak power delivered by the klystrons in the NLCRA (Next Linear Collider Test Accelerator) now under construction at SLAC is enhanced by a factor of four in a SLED-II type of R.F. pulse compression system (pulse width compression ratio of six). To achieve the desired output pulse duration of 250 ns, a delay line constructed from a 36 m length of circular waveguide is used. Future colliders, however, will require even higher peak power and larger compression factors, which favors a more efficient binary pulse compression approach. Binary pulse compression, however, requires a line whose delay time is approximatelymore » proportional to the compression factor. To reduce the length of these lines to manageable proportions, periodically loaded delay lines are being analyzed using a generalized scattering matrix approach. One issue under study is the possibility of propagating two TE{sub o} modes, one with a high group velocity and one with a group velocity of the order 0.05c, for use in a single-line binary pulse compression system. Particular attention is paid to time domain pulse degradation and to Ohmic losses.« less

Long-term change in benthopelagic fish abundance in the abyssal northeast Pacific Ocean.

PubMed

Bailey, D M; Ruhl, H A; Smith, K L

2006-03-01

Food web structure, particularly the relative importance of bottom-up and top-down control of animal abundances, is poorly known for the Earth's largest habitats: the abyssal plains. A unique 15-yr time series of climate, productivity, particulate flux, and abundance of primary consumers (primarily echinoderms) and secondary consumers (fish) was examined to elucidate the response of trophic levels to temporal variation in one another. Towed camera sled deployments in the abyssal northeast Pacific (4100 m water depth) showed that annual mean numbers of the dominant fish genus (Coryphaenoides spp.) more than doubled over the period 1989-2004. Coryphaenoides spp. abundance was significantly correlated with total abundance of mobile epibenthic megafauna (echinoderms), with changes in fish abundance lagging behind changes in the echinoderms. Direct correlations between surface climate and fish abundances, and particulate organic carbon (POC) flux and fish abundances, were insignificant, which may be related to the varied response of the potential prey taxa to climate and POC flux. This study provides a rare opportunity to study the long-term dynamics of an unexploited marine fish population and suggests a dominant role for bottom-up control in this system.

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.

Time-dependent inertia analysis of vehicle mechanisms

NASA Astrophysics Data System (ADS)

Salmon, James Lee

Two methods for performing transient inertia analysis of vehicle hardware systems are developed in this dissertation. The analysis techniques can be used to predict the response of vehicle mechanism systems to the accelerations associated with vehicle impacts. General analytical methods for evaluating translational or rotational system dynamics are generated and evaluated for various system characteristics. The utility of the derived techniques are demonstrated by applying the generalized methods to two vehicle systems. Time dependent acceleration measured during a vehicle to vehicle impact are used as input to perform a dynamic analysis of an automobile liftgate latch and outside door handle. Generalized Lagrange equations for a non-conservative system are used to formulate a second order nonlinear differential equation defining the response of the components to the transient input. The differential equation is solved by employing the fourth order Runge-Kutta method. The events are then analyzed using commercially available two dimensional rigid body dynamic analysis software. The results of the two analytical techniques are compared to experimental data generated by high speed film analysis of tests of the two components performed on a high G acceleration sled at Ford Motor Company.

Seat design principles to reduce neck injuries in rear impacts.

PubMed

Viano, David C

2008-12-01

In the 1990s, research was conducted at General Motors R&D Center on seat safety in rear impacts. It led to the development of high retention seats and an active head restraint to improve occupant safety. This article provides an overview of the design principles found from that research and focuses on seat characteristics that lower whiplash risks. Sled and quasistatic seat testing showed how occupants interact with the seat in rear impacts and what seat characteristics improve occupant retention, energy management, and support of the head-neck, lowering injury risks. Neck displacements, moments, and forces were used to assess whiplash and more severe injury risks. A QST test was developed to quasi-statically push a dummy rearward into the seat to determine seat stiffness (k), frame strength (j), and peak bending moment (M(Hpt)). These parameters were related to neck displacements associated with whiplash. Sled tests were run with in-position and out-of-position male and female Hybrid III dummies to assess performance. A high retention seat and active head restraint were developed and put into production in 1997. High retention seats have 2.3 times greater moment, develop 2.2 times greater load, but have the same stiffness as earlier yielding seats. Seat stiffness was found to be a principle characteristic related to neck displacements associated with whiplash. The combination of a stronger frame, yielding seatback, and high-forward head restraint in the high retention seat provides early head support and low neck displacements in rear impacts. Larger reductions in neck displacement were obtained by adding an active head restraint that moves the head restraint forward and upward by occupant penetration into the seatback. This substantially reduces head contact time, neck displacements, and loads. Whiplash risks are related to seat stiffness, the position of the head restraint, and frame strength. Low seat stiffness allows the occupant to move into the seatback

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

Occurrence, clinical features and outcome of canine pancreatitis (80 cases).

PubMed

Pápa, Kinga; Máthé, Akos; Abonyi-Tóth, Zsolt; Sterczer, Agnes; Psáder, Roland; Hetyey, Csaba; Vajdovich, Péter; Vörös, Károly

2011-03-01

Medical records of 80 dogs diagnosed with acute pancreatitis during a 4-year period were evaluated regarding history, breed predilection, clinical signs and additional examination findings. Cases were selected if compatible clinical symptoms, increased serum activity of amylase or lipase and morphologic evidence of pancreatitis by ultrasonography, laparotomy or necropsy were all present. Like in other studies, neutered dogs had an increased risk of developing acute pancreatitis. Although breed predilection was consistent with earlier reports, some notable differences were also observed. Apart from Dachshunds, Poodles, Cocker Spaniels and Fox Terriers, the sled dogs (Laikas, Alaskan Malamutes) also demonstrated a higher risk for pancreatitis according to our results. Concurrent diseases occurred in 56 dogs (70%), diabetes mellitus (n = 29, 36%) being the most common. Clinical signs of acute pancreatitis were similar to those observed in other studies. The study group represented a dog population with severe acute pancreatitis, having a relatively high mortality rate (40%) compared to data of the literature. Breed, age, gender, neutering and body condition had no significant association with the outcome. Hypothermia (p = 0.0413) and metabolic acidosis (p = 0.0063) correlated significantly with poor prognosis and may serve as valuable markers for severity assessment in canine acute pancreatitis.

Using Enterprise Architecture for Analysis of a Complex Adaptive Organization's Risk Inducing Characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salguero, Laura Marie; Huff, Johnathon; Matta, Anthony R.

Sandia National Laboratories is an organization with a wide range of research and development activities that include nuclear, explosives, and chemical hazards. In addition, Sandia has over 2000 labs and over 40 major test facilities, such as the Thermal Test Complex, the Lightning Test Facility, and the Rocket Sled Track. In order to support safe operations, Sandia has a diverse Environment, Safety, and Health (ES&H) organization that provides expertise to support engineers and scientists in performing work safely. With such a diverse organization to support, the ES&H program continuously seeks opportunities to improve the services provided for Sandia by usingmore » various methods as part of their risk management strategy. One of the methods being investigated is using enterprise architecture analysis to mitigate risk inducing characteristics such as normalization of deviance, organizational drift, and problems in information flow. This paper is a case study for how a Department of Defense Architecture Framework (DoDAF) model of the ES&H enterprise, including information technology applications, can be analyzed to understand the level of risk associated with the risk inducing characteristics discussed above. While the analysis is not complete, we provide proposed analysis methods that will be used for future research as the project progresses.« less

Bicycle helmet use and non-use – recently published research

PubMed Central

2012-01-01

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. PMID:22632628

Development and validation of a modified Hybrid-III six-year-old dummy model for simulating submarining in motor-vehicle crashes.

PubMed

Hu, Jingwen; Klinich, Kathleen D; Reed, Matthew P; Kokkolaras, Michael; Rupp, Jonathan D

2012-06-01

In motor-vehicle crashes, young school-aged children restrained by vehicle seat belt systems often suffer from abdominal injuries due to submarining. However, the current anthropomorphic test device, so-called "crash dummy", is not adequate for proper simulation of submarining. In this study, a modified Hybrid-III six-year-old dummy model capable of simulating and predicting submarining was developed using MADYMO (TNO Automotive Safety Solutions). The model incorporated improved pelvis and abdomen geometry and properties previously tested in a modified physical dummy. The model was calibrated and validated against four sled tests under two test conditions with and without submarining using a multi-objective optimization method. A sensitivity analysis using this validated child dummy model showed that dummy knee excursion, torso rotation angle, and the difference between head and knee excursions were good predictors for submarining status. It was also shown that restraint system design variables, such as lap belt angle, D-ring height, and seat coefficient of friction (COF), may have opposite effects on head and abdomen injury risks; therefore child dummies and dummy models capable of simulating submarining are crucial for future restraint system design optimization for young school-aged children. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

GaN-based superluminescent diodes with long lifetime

NASA Astrophysics Data System (ADS)

Castiglia, A.; Rossetti, M.; Matuschek, N.; Rezzonico, R.; Duelk, M.; Vélez, C.; Carlin, J.-F.; Grandjean, N.

2016-02-01

We report on the reliability of GaN-based super-luminescent light emitting diodes (SLEDs) emitting at a wavelength of 405 nm. We show that the Mg doping level in the p-type layers has an impact on both the device electro-optical characteristics and their reliability. Optimized doping levels allow decreasing the operating voltage on single-mode devices from more than 6 V to less than 5 V for an injection current of 100 mA. Furthermore, maximum output powers as high as 350 mW (for an injection current of 500 mA) have been achieved in continuous-wave operation (CW) at room temperature. Modules with standard and optimized p-type layers were finally tested in terms of lifetime, at a constant output power of 10 mW, in CW operation and at a case temperature of 25 °C. The modules with non-optimized p-type doping showed a fast and remarkable increase in the drive current during the first hundreds of hours together with an increase of the device series resistance. No degradation of the electrical characteristics was observed over 2000 h on devices with optimized p-type layers. The estimated lifetime for those devices was longer than 5000 h.

Effects of Droplet Size on Intrusion of Sub-Surface Oil Spills

NASA Astrophysics Data System (ADS)

Adams, Eric; Chan, Godine; Wang, Dayang

2014-11-01

We explore effects of droplet size on droplet intrusion and transport in sub-surface oil spills. Negatively buoyant glass beads released continuously to a stratified ambient simulate oil droplets in a rising multiphase plume, and distributions of settled beads are used to infer signatures of surfacing oil. Initial tests used quiescent conditions, while ongoing tests simulate currents by towing the source and a bottom sled. Without current, deposited beads have a Gaussian distribution, with variance increasing with decreasing particle size. Distributions agree with a model assuming first order particle loss from an intrusion layer of constant thickness, and empirically determined flow rate. With current, deposited beads display a parabolic distribution similar to that expected from a source in uniform flow; we are currently comparing observed distributions with similar analytical models. Because chemical dispersants have been used to reduce oil droplet size, our study provides one measure of their effectiveness. Results are applied to conditions from the `Deep Spill' field experiment, and the recent Deepwater Horizon oil spill, and are being used to provide ``inner boundary conditions'' for subsequent far field modeling of these events. This research was made possible by grants from Chevron Energy Technology Co., through the Chevron-MITEI University Partnership Program, and BP/The Gulf of Mexico Research Initiative, GISR.

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.

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.

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.

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.

Evaluation of kinematics and injuries to restrained occupants in far-side crashes using full-scale vehicle and human body models.

PubMed

Arun, Mike W J; Umale, Sagar; Humm, John R; Yoganandan, Narayan; Hadagali, Prasanaah; Pintar, Frank A

2016-09-01

The objective of the current study was to perform a parametric study with different impact objects, impact locations, and impact speeds by analyzing occupant kinematics and injury estimations using a whole-vehicle and whole-body finite element-human body model (FE-HBM). To confirm the HBM responses, the biofidelity of the model was validated using data from postmortem human surrogate (PMHS) sled tests. The biofidelity of the model was validated using data from sled experiments and correlational analysis (CORA). Full-scale simulations were performed using a restrained Global Human Body Model Consortium (GHBMC) model seated on a 2001 Ford Taurus model using a far-side lateral impact condition. The driver seat was placed in the center position to represent a nominal initial impact condition. A 3-point seat belt with pretensioner and retractor was used to restrain the GHBMC model. A parametric study was performed using 12 simulations by varying impact locations, impacting object, and impact speed using the full-scale models. In all 12 simulations, the principal direction of force (PDOF) was selected as 90°. The impacting objects were a 10-in.-diameter rigid vertical pole and a movable deformable barrier. The impact location of the pole was at the C-pillar in the first case, at the B-pillar in the second case, and, finally, at the A-pillar in the third case. The vehicle and the GHBMC models were defined an initial velocity of 35 km/h (high speed) and 15 km/h (low speed). Excursion of the head center of gravity (CG), T6, and pelvis were measured from the simulations. In addition, injury risk estimations were performed on head, rib cage, lungs, kidneys, liver, spleen, and pelvis. The average CORA rating was 0.7. The shoulder belt slipped in B- and C-pillar impacts but somewhat engaged in the A-pillar case. In the B-pillar case, the head contacted the intruding struck-side structures, indicating higher risk of injury. Occupant kinematics depended on interaction with

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

The repeatability and reproducibility of the BioRID IIg in a repeatable laboratory seat based on a production car seat.

PubMed

Hynd, David; Depinet, Paul; Lorenz, Bernd

2013-01-01

The United Nations Economic Commission for Europe Informal Group on GTR No. 7 Phase 2 are working to define a build level for the BioRID II rear impact (whiplash) crash test dummy that ensures repeatable and reproducible performance in a test procedure that has been proposed for future legislation. This includes the specification of dummy hardware, as well as the development of comprehensive certification procedures for the dummy. This study evaluated whether the dummy build level and certification procedures deliver the desired level of repeatability and reproducibility. A custom-designed laboratory seat was made using the seat base, back, and head restraint from a production car seat to ensure a representative interface with the dummy. The seat back was reinforced for use in multiple tests and the recliner mechanism was replaced by an external spring-damper mechanism. A total of 65 tests were performed with 6 BioRID IIg dummies using the draft GTR No.7 sled pulse and seating procedure. All dummies were subject to the build, maintenance, and certification procedures defined by the Informal Group. The test condition was highly repeatable, with a very repeatable pulse, a well-controlled seat back response, and minimal observed degradation of seat foams. The results showed qualitatively reasonable repeatability and reproducibility for the upper torso and head accelerations, as well as for T1 Fx and upper neck Fx . However, reproducibility was not acceptable for T1 and upper neck Fz or for T1 and upper neck My . The Informal Group has not selected injury or seat assessment criteria for use with BioRID II, so it is not known whether these channels would be used in the regulation. However, the ramping-up behavior of the dummy showed poor reproducibility, which would be expected to affect the reproducibility of dummy measurements in general. Pelvis and spine characteristics were found to significantly influence the dummy measurements for which poor reproducibility was

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.

Compressed gas combined single- and two-stage light-gas gun

NASA Astrophysics Data System (ADS)

Lamberson, L. E.; Boettcher, P. A.

2018-02-01

With more than 1 trillion artificial objects smaller than 1 μm in low and geostationary Earth orbit, space assets are subject to the constant threat of space debris impact. These collisions occur at hypervelocity or speeds greater than 3 km/s. In order to characterize material behavior under this extreme event as well as study next-generation materials for space exploration, this paper presents a unique two-stage light-gas gun capable of replicating hypervelocity impacts. While a limited number of these types of facilities exist, they typically are extremely large and can be costly and dangerous to operate. The design presented in this paper is novel in two distinct ways. First, it does not use a form of combustion in the first stage. The projectile is accelerated from a pressure differential using air and inert gases (or purely inert gases), firing a projectile in a nominal range of 1-4 km/s. Second, the design is modular in that the first stage sits on a track sled and can be pulled back and used in itself to study lower speed impacts without any further modifications, with the first stage piston as the impactor. The modularity of the instrument allows the ability to investigate three orders of magnitude of impact velocities or between 101 and 103 m/s in a single, relatively small, cost effective instrument.

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.

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.

Development and Validation of an Older Occupant Finite Element Model of a Mid-Sized Male for Investigation of Age-related Injury Risk.

PubMed

Schoell, Samantha L; Weaver, Ashley A; Urban, Jillian E; Jones, Derek A; Stitzel, Joel D; Hwang, Eunjoo; Reed, Matthew P; Rupp, Jonathan D; Hu, Jingwen

2015-11-01

The aging population is a growing concern as the increased fragility and frailty of the elderly results in an elevated incidence of injury as well as an increased risk of mortality and morbidity. To assess elderly injury risk, age-specific computational models can be developed to directly calculate biomechanical metrics for injury. The first objective was to develop an older occupant Global Human Body Models Consortium (GHBMC) average male model (M50) representative of a 65 year old (YO) and to perform regional validation tests to investigate predicted fractures and injury severity with age. Development of the GHBMC M50 65 YO model involved implementing geometric, cortical thickness, and material property changes with age. Regional validation tests included a chest impact, a lateral impact, a shoulder impact, a thoracoabdominal impact, an abdominal bar impact, a pelvic impact, and a lateral sled test. The second objective was to investigate age-related injury risks by performing a frontal US NCAP simulation test with the GHBMC M50 65 YO and the GHBMC M50 v4.2 models. Simulation results were compared to the GHBMC M50 v4.2 to evaluate the effect of age on occupant response and risk for head injury, neck injury, thoracic injury, and lower extremity injury. Overall, the GHBMC M50 65 YO model predicted higher probabilities of AIS 3+ injury for the head and thorax.

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.

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.

Biomechanical Tolerance of Calcaneal Fractures

PubMed Central

Yoganandan, Narayan; Pintar, Frank A.; Gennarelli, Thomas A.; Seipel, Robert; Marks, Richard

1999-01-01

Biomechanical studies have been conducted in the past to understand the mechanisms of injury to the foot-ankle complex. However, statistically based tolerance criteria for calcaneal complex injuries are lacking. Consequently, this research was designed to derive a probability distribution that represents human calcaneal tolerance under impact loading such as those encountered in vehicular collisions. Information for deriving the distribution was obtained by experiments on unembalmed human cadaver lower extremities. Briefly, the protocol included the following. The knee joint was disarticulated such that the entire lower extremity distal to the knee joint remained intact. The proximal tibia was fixed in polymethylmethacrylate. The specimens were aligned and impact loading was applied using mini-sled pendulum equipment. The pendulum impactor dynamically loaded the plantar aspect of the foot once. Following the test, specimens were palpated and radiographs in multiple planes were obtained. Injuries were classified into no fracture, and extra-and intra-articular fractures of the calcaneus. There were 14 cases of no injury and 12 cases of calcaneal fracture. The fracture forces (mean: 7802 N) were significantly different (p<0.01) from the forces in the no injury (mean: 4144 N) group. The probability of calcaneal fracture determined using logistic regression indicated that a force of 6.2 kN corresponds to 50 percent probability of calcaneal fracture. The derived probability distribution is useful in the design of dummies and vehicular surfaces.

Compressed gas combined single- and two-stage light-gas gun.

PubMed

Lamberson, L E; Boettcher, P A

2018-02-01

With more than 1 trillion artificial objects smaller than 1 μm in low and geostationary Earth orbit, space assets are subject to the constant threat of space debris impact. These collisions occur at hypervelocity or speeds greater than 3 km/s. In order to characterize material behavior under this extreme event as well as study next-generation materials for space exploration, this paper presents a unique two-stage light-gas gun capable of replicating hypervelocity impacts. While a limited number of these types of facilities exist, they typically are extremely large and can be costly and dangerous to operate. The design presented in this paper is novel in two distinct ways. First, it does not use a form of combustion in the first stage. The projectile is accelerated from a pressure differential using air and inert gases (or purely inert gases), firing a projectile in a nominal range of 1-4 km/s. Second, the design is modular in that the first stage sits on a track sled and can be pulled back and used in itself to study lower speed impacts without any further modifications, with the first stage piston as the impactor. The modularity of the instrument allows the ability to investigate three orders of magnitude of impact velocities or between 10 1 and 10 3 m/s in a single, relatively small, cost effective instrument.

Trunk muscle recruitment patterns in simulated precrash events.

PubMed

Ólafsdóttir, Jóna Marín; Fice, Jason B; Mang, Daniel W H; Brolin, Karin; Davidsson, Johan; Blouin, Jean-Sébastien; Siegmund, Gunter P

2018-02-28

To quantify trunk muscle activation levels during whole body accelerations that simulate precrash events in multiple directions and to identify recruitment patterns for the development of active human body models. Four subjects (1 female, 3 males) were accelerated at 0.55 g (net Δv = 4.0 m/s) in 8 directions while seated on a sled-mounted car seat to simulate a precrash pulse. Electromyographic (EMG) activity in 4 trunk muscles was measured using wire electrodes inserted into the left rectus abdominis, internal oblique, iliocostalis, and multifidus muscles at the L2-L3 level. Muscle activity evoked by the perturbations was normalized by each muscle's isometric maximum voluntary contraction (MVC) activity. Spatial tuning curves were plotted at 150, 300, and 600 ms after acceleration onset. EMG activity remained below 40% MVC for the three time points for most directions. At the 150- and 300 ms time points, the highest EMG amplitudes were observed during perturbations to the left (-90°) and left rearward (-135°). EMG activity diminished by 600 ms for the anterior muscles, but not for the posterior muscles. These preliminary results suggest that trunk muscle activity may be directionally tuned at the acceleration level tested here. Although data from more subjects are needed, these preliminary data support the development of modeled trunk muscle recruitment strategies in active human body models that predict occupant responses in precrash scenarios.

Illustrations of the importance of mass wasting in the evolution of continental margins

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 andmore » 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.« less

A versatile stereoscopic visual display system for vestibular and oculomotor research.

PubMed

Kramer, P D; Roberts, D C; Shelhamer, M; Zee, D S

1998-01-01

Testing of the vestibular system requires a vestibular stimulus (motion) and/or a visual stimulus. We have developed a versatile, low cost, stereoscopic visual display system, using "virtual reality" (VR) technology. The display system can produce images for each eye that correspond to targets at any virtual distance relative to the subject, and so require the appropriate ocular vergence. We elicited smooth pursuit, "stare" optokinetic nystagmus (OKN) and after-nystagmus (OKAN), vergence for targets at various distances, and short-term adaptation of the vestibulo-ocular reflex (VOR), using both conventional methods and the stereoscopic display. Pursuit, OKN, and OKAN were comparable with both methods. When used with a vestibular stimulus, VR induced appropriate adaptive changes of the phase and gain of the angular VOR. In addition, using the VR display system and a human linear acceleration sled, we adapted the phase of the linear VOR. The VR-based stimulus system not only offers an alternative to more cumbersome means of stimulating the visual system in vestibular experiments, it also can produce visual stimuli that would otherwise be impractical or impossible. Our techniques provide images without the latencies encountered in most VR systems. Its inherent versatility allows it to be useful in several different types of experiments, and because it is software driven it can be quickly adapted to provide a new stimulus. These two factors allow VR to provide considerable savings in time and money, as well as flexibility in developing experimental paradigms.

The effects of forced small-wavelength, finite-bandwidth initial perturbations and miscibility on the turbulent Rayleigh–Taylor instability

DOE PAGES

Roberts, M. S.; Jacobs, J. W.

2015-12-07

Rayleigh–Taylor instability experiments are performed using both immiscible and miscible incompressible liquid combinations having a relatively large Atwood number ofmore » $$A\\equiv ({\\it\\rho}_{2}-{\\it\\rho}_{1})/({\\it\\rho}_{2}+{\\it\\rho}_{1})=0.48$$. The liquid-filled tank is attached to a test sled that is accelerated downwards along a vertical rail system using a system of weights and pulleys producing approximately$1g$$net acceleration. The tank is backlit and images are digitally recorded using a high-speed video camera. The experiments are either initiated with forced initial perturbations or are left unforced. The forced experiments have an initial perturbation imposed by vertically oscillating the liquid-filled tank to produce Faraday waves at the interface. The unforced experiments rely on random interfacial fluctuations, resulting from background noise, to seed the instability. The main focus of this study is to determine the effects of forced initial perturbations and the effects of miscibility on the growth parameter,$${\\it\\alpha}$$. Measurements of the mixing-layer width,$$h$$, are acquired, from which$${\\it\\alpha}$$is determined. It is found that initial perturbations of the form used in this study do not affect measured$${\\it\\alpha}$$values. However, miscibility is observed to strongly affect$${\\it\\alpha}$$, resulting in a factor of two reduction in its value, a finding not previously observed in past experiments. In addition, all measured$${\\it\\alpha}$values are found to be smaller than those obtained in previous experimental studies.« less

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.

Splenic trauma as an adverse effect of torso-protecting side airbags: biomechanical and case evidence.

PubMed

Hallman, Jason J; Brasel, Karen J; Yoganandan, Narayan; Pintar, Frank A

2009-10-01

Injury mechanisms from frontal airbags, first identified in anecdotal reports, are now well documented for pediatric, small female, and out-of-position occupants. In contrast, torso side airbags have not yet been consistently associated with specific injury risks in field assessments. To determine possible torso side airbag-related injuries, the present study identified crashes involving side airbags from reports within the CIREN, NASS, and SCI databases. Injury patterns were compared to patterns from lateral crashes in absence of side airbag. Splenic trauma (AIS 3+) was found present in five cases of torso side airbag deployment at lower impact severity (as measured by velocity change and compartment intrusion) than cases of splenic trauma without side airbag. Five additional cases were found to contain similar injury patterns but occurred with greater crash severity. To supplement case analyses, full scale sled tests were conducted with a THOR-NT dummy and cadaveric specimen. Four THOR tests with door- and seat-mounted torso side airbags confirmed that out-of-position (early inflation stage) airbag contact elevated thoracic injury metrics compared to optimal (fully inflated) contact. Out-of-position seat-mounted airbag deployment also produced AIS 3 splenic trauma in the cadaveric specimen. Due to potentially sudden or delayed onset of intraperitoneal hemorrhage and hypovolemic shock following splenic trauma, further biomechanical investigation of this anecdotal evidence is essential to identify injury mechanisms, prevention techniques, and methods for early diagnosis.

Splenic Trauma as an Adverse Effect of Torso-Protecting Side Airbags: Biomechanical and Case Evidence

PubMed Central

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

2009-01-01

Injury mechanisms from frontal airbags, first identified in anecdotal reports, are now well documented for pediatric, small female, and out-of-position occupants. In contrast, torso side airbags have not yet been consistently associated with specific injury risks in field assessments. To determine possible torso side airbag-related injuries, the present study identified crashes involving side airbags from reports within the CIREN, NASS, and SCI databases. Injury patterns were compared to patterns from lateral crashes in absence of side airbag. Splenic trauma (AIS 3+) was found present in five cases of torso side airbag deployment at lower impact severity (as measured by velocity change and compartment intrusion) than cases of splenic trauma without side airbag. Five additional cases were found to contain similar injury patterns but occurred with greater crash severity. To supplement case analyses, full scale sled tests were conducted with a THOR-NT dummy and cadaveric specimen. Four THOR tests with door- and seat-mounted torso side airbags confirmed that out-of-position (early inflation stage) airbag contact elevated thoracic injury metrics compared to optimal (fully inflated) contact. Out-of-position seat-mounted airbag deployment also produced AIS 3 splenic trauma in the cadaveric specimen. Due to potentially sudden or delayed onset of intraperitoneal hemorrhage and hypovolemic shock following splenic trauma, further biomechanical investigation of this anecdotal evidence is essential to identify injury mechanisms, prevention techniques, and methods for early diagnosis. PMID:20184829

Sibling power: influence of older siblings' persuasive appeals on younger siblings' judgements about risk taking behaviours.

PubMed Central

Morrongiello, B. A.; Bradley, M. D.

1997-01-01

OBJECTIVES: Although many injuries happen when school age children are away from home and in the company of other children, we know surprisingly little about interpersonal influences on children's risk taking decisions. The aim of the present study was to examine the influence of older siblings' persuasive appeals on young children's decisions about engaging in behaviours that could threaten their physical safety. METHODS: Forty same sex sibling pairs participated. Children were shown drawings of play scenes (bicycling, river crossing, and sledding), with each depicting lower and higher risk paths of travel. Children of 8 years made initial decisions as to which paths they would take. Subsequently, their older sibling acted as a confederate and tried to persuade them to change their decisions. RESULTS: After the appeals of older siblings, younger children significantly shifted their decisions: choices of less risky paths replaced the initial selection of more risky paths, and vice versa. A positive sibling relationship was predictive of younger siblings' decision changes. Boys and girls were equally effective in persuasion but they did so using different types of arguments, with boys communicating primarily appeals to fun and girls emphasizing appeals to safety. CONCLUSIONS: These findings highlight the effect that older siblings can have on risk taking decisions of younger siblings. Accordingly, they document the importance of considering the interpersonal context of risk taking when designing interventions to reduce injuries among elementary schoolchildren. Images PMID:9113843

Oblique Loading in Post Mortem Human Surrogates from Vehicle Lateral Impact Tests using Chestbands.

PubMed

Yoganandan, Narayan; Humm, John R; Pintar, Frank A; Arun, Mike W J; Rhule, Heather; Rudd, Rodney; Craig, Matthew

2015-11-01

While numerous studies have been conducted to determine side impact responses of Post Mortem Human Surrogates (PMHS) using sled and other equipment, experiments using the biological surrogate in modern full-scale vehicles are not available. The present study investigated the presence of oblique loading in moving deformable barrier and pole tests. Threepoint belt restrained PMHS were positioned in the left front and left rear seats in the former and left front seat in the latter condition and tested according to consumer testing protocols. Three chestbands were used in each specimen (upper, middle and lower thorax). Accelerometers were secured to the skull, shoulder, upper, middle and lower thoracic vertebrae, sternum, and sacrum. Chestband signals were processed to determine magnitudes and angulations of peak deflections. The magnitude and timing of various signal peaks are given. Vehicle accelerations, door velocities, and seat belt loads are also given. Analysis of deformation contours, peak deflections, and angulations indicated that the left rear seated specimen were exposed to anterior oblique loading while left front specimens in both tests sustained essentially pure lateral loading to the torso. These data can be used to validate human body computational models. The occurrence of oblique loading in full-scale testing, hitherto unrecognized, may serve to stimulate the exploration of its role in injuries to the thorax and lower extremities in modern vehicles. It may be important to continue research in this area because injury metrics have a lower threshold for angled loading.

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.

Gallium nitride light sources for optical coherence tomography

NASA Astrophysics Data System (ADS)

Goldberg, Graham R.; Ivanov, Pavlo; Ozaki, Nobuhiko; Childs, David T. D.; Groom, Kristian M.; Kennedy, Kenneth L.; Hogg, Richard A.

2017-02-01

The advent of optical coherence tomography (OCT) has permitted high-resolution, non-invasive, in vivo imaging of the eye, skin and other biological tissue. The axial resolution is limited by source bandwidth and central wavelength. With the growing demand for short wavelength imaging, super-continuum sources and non-linear fibre-based light sources have been demonstrated in tissue imaging applications exploiting the near-UV and visible spectrum. Whilst the potential has been identified of using gallium nitride devices due to relative maturity of laser technology, there have been limited reports on using such low cost, robust devices in imaging systems. A GaN super-luminescent light emitting diode (SLED) was first reported in 2009, using tilted facets to suppress lasing, with the focus since on high power, low speckle and relatively low bandwidth applications. In this paper we discuss a method of producing a GaN based broadband source, including a passive absorber to suppress lasing. The merits of this passive absorber are then discussed with regards to broad-bandwidth applications, rather than power applications. For the first time in GaN devices, the performance of the light sources developed are assessed though the point spread function (PSF) (which describes an imaging systems response to a point source), calculated from the emission spectra. We show a sub-7μm resolution is possible without the use of special epitaxial techniques, ultimately outlining the suitability of these short wavelength, broadband, GaN devices for use in OCT applications.

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.

Rapid neck muscle adaptation alters the head kinematics of aware and unaware subjects undergoing multiple whiplash-like perturbations.

PubMed

Siegmund, Gunter P; Sanderson, David J; Myers, Barry S; Inglis, J Timothy

2003-04-01

To examine whether habituation confounds the study of whiplash injury using human subjects, we quantified changes in the magnitude and temporal development of the neck muscle electromyogram and peak linear and angular head/torso kinematics of subjects exposed to sequential whiplash-like perturbations. Forty-four seated subjects (23F, 21M) underwent 11 consecutive forward horizontal perturbations (peak sled acceleration=1.5 g). Electromyographic (EMG) activity was recorded over the sternocleidomastoid (SCM) and cervical paraspinal (PARA) muscles with surface electrodes, and head and torso kinematics were measured using linear and angular accelerometers and a 3D motion analysis system. EMG onset occurred at reflex latencies (67-75 ms in SCM) and did not vary with repeated perturbations. EMG amplitude was significantly attenuated by the second perturbation in PARA muscles and by the third perturbation in SCM muscles. The mean decrement in EMG amplitude between the first trial and the mean of the last five trials was between 41% and 64%. Related kinematic changes ranged from a 21% increase in head extension angle to a 29% decrease in forward acceleration at the forehead, and were also significantly different by the second exposure in some variables. Although a wider range of perturbation intensities and inter-perturbation intervals need to be studied, the significant changes observed in both muscle and kinematic variables by the second perturbation indicated that habituation was a potential confounder of whiplash injury studies using repeated perturbations of human subjects.

Kinematic response of the spine during simulated aircraft ejections.

PubMed

Damon, Andrew M; Lessley, David J; Salzar, Robert S; Bass, Cameron R; Shen, Francis H; Paskoff, Glenn R; Shender, Barry S

2010-05-01

Military aviators are susceptible to spinal injuries during high-speed ejection scenarios. These injuries commonly arise as a result of strains induced by extreme flexion or compression of the spinal column. This study characterizes the vertebral motion of two postmortem human surrogates (PMHS) during a simulated catapult phase of ejection on a horizontal decelerator sled. During testing, the PMHS were restrained supinely to a mock ejection seat and subjected to a horizontal deceleration profile directed along the local z-axis. Two midsized males (175.3 cm, 77.1 kg; 185.4 cm, 72.6 kg) were tested. High-rate motion capture equipment was used to measure the three-dimensional displacement of the head, vertebrae, and pelvis during the ejection event. The two PMHS showed generally similar kinematic motion. Head injury criterion (HIC) results were well below injury threshold levels for both specimens. The specimens both showed compression of the spine, with a reduction in length of 23.9 mm and 45.7 mm. Post-test autopsies revealed fractures in the C5, T1, and L1 vertebrae. This paper provides an analysis of spinal motion during an aircraft ejection.The injuries observed in the test subjects were consistent with those seen in epidemiological studies. Future studies should examine the effects of gender, muscle tensing, out-of-position (of head from neutral position) occupants, and external forces (e.g., windblast) on spinal kinematics during aircraft ejection.

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.

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.

A revolution in preventing fatal craniovertebral junction injuries: lessons learned from the Head and Neck Support device in professional auto racing.

PubMed

Kaul, Anand; Abbas, Ahmed; Smith, Gabriel; Manjila, Sunil; Pace, Jonathan; Steinmetz, Michael

2016-12-01

Fatal craniovertebral junction (CVJ) injuries were the most common cause of death in high-speed motor sports prior to 2001. Following the death of a mutual friend and race car driver, Patrick Jacquemart (1946-1981), biomechanical engineer Dr. Robert Hubbard, along with race car driver and brother-in-law Jim Downing, developed the concept for the Head and Neck Support (HANS) device to prevent flexion-distraction injuries during high-velocity impact. Biomechanical testing showed that neck shear and loading forces experienced during collisions were 3 times the required amount for a catastrophic injury. Crash sled testing with and without the HANS device elucidated reductions in neck tension, neck compression, head acceleration, and chest acceleration experienced by dummies during high-energy crashes. Simultaneously, motor sports accidents such as Dale Earnhardt Sr.'s fatal crash in 2001 galvanized public opinion in favor of serious safety reform. Analysis of Earnhardt's accident demonstrated that his car's velocity parallel to the barrier was more than 150 miles per hour (mph), with deceleration upon impact of roughly 43 mph in a total of 0.08 seconds. After careful review, several major racing series such as the National Association for Stock Car Auto Racing (NASCAR) and Championship Auto Racing Team (CART) made major changes to ensure the safety of drivers at the turn of the 21st century. Since the rule requiring the HANS device in professional auto racing series was put in place, there has not been a single reported case of a fatal CVJ injury.

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.

Handedness results from Complementary Hemispheric Dominance, not Global Hemispheric Dominance: Evidence from Mechanically Coupled Bilateral Movements.

PubMed

Woytowicz, Elizabeth J; Westlake, Kelly P; Whitall, Jill; Sainburg, Robert L

2018-05-09

Two contrasting views of handedness can be described as 1) complementary dominance, in which each hemisphere is specialized for different aspects of motor control, and 2) global dominance, in which the hemisphere contralateral to the dominant arm is specialized for all aspects of motor control. The present study sought to determine which motor lateralization hypothesis best predicts motor performance during common bilateral task of stabilizing an object (e.g. bread) with one hand while applying forces to the object (e.g. slicing) using the other hand. We designed an experimental equivalent of this task, performed in a virtual environment with the unseen arms supported by frictionless air-sleds. The hands were connected by a spring, and the task was to maintain the position of one hand, while moving the other hand to a target. Thus, the reaching hand was required to take account of the spring load to make smooth and accurate trajectories, while the stabilizer hand was required to impede the spring load to keep a constant position. Right-handed subjects performed two task sessions (right hand reach and left hand stabilize; left hand reach and right hand stabilize) with the order of the sessions counterbalanced between groups. Our results indicate a hand by task-component interaction, such that the right hand showed straighter reaching performance while the left showed more stable holding performance. These findings provide support for the complementary dominance hypothesis and suggest that the specializations of each cerebral hemisphere for impedance and dynamic control mechanisms are expressed during bilateral interactive tasks.

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

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.

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.

Evacuation of Intensive Care Units During Disaster: Learning From the Hurricane Sandy Experience.

PubMed

King, Mary A; Dorfman, Molly V; Einav, Sharon; Niven, Alex S; Kissoon, Niranjan; Grissom, Colin K

2016-02-01

Data on best practices for evacuating an intensive care unit (ICU) during a disaster are limited. The impact of Hurricane Sandy on New York City area hospitals provided a unique opportunity to learn from the experience of ICU providers about their preparedness, perspective, roles, and activities. We conducted a cross-sectional survey of nurses, respiratory therapists, and physicians who played direct roles during the Hurricane Sandy ICU evacuations. Sixty-eight health care professionals from 4 evacuating hospitals completed surveys (35% ICU nurses, 21% respiratory therapists, 25% physicians-in-training, and 13% attending physicians). Only 21% had participated in an ICU evacuation drill in the past 2 years and 28% had prior training or real-life experience. Processes were inconsistent for patient prioritization, tracking, transport medications, and transport care. Respondents identified communication (43%) as the key barrier to effective evacuation. The equipment considered most helpful included flashlights (24%), transport sleds (21%), and oxygen tanks and respiratory therapy supplies (19%). An evacuation wish list included walkie-talkies/phones (26%), lighting/electricity (18%), flashlights (10%), and portable ventilators and suction (16%). ICU providers who evacuated critically ill patients during Hurricane Sandy had little prior knowledge of evacuation processes or vertical evacuation experience. The weakest links in the patient evacuation process were communication and the availability of practical tools. Incorporating ICU providers into hospital evacuation planning and training, developing standard evacuation communication processes and tools, and collecting a uniform dataset among all evacuating hospitals could better inform critical care evacuation in the future.

The Blue Ribbon Panel on Depowered and Advanced Airbags — Status Report on Airbag Performance

PubMed Central

Ferguson, Susan A.; Schneider, Lawrence; Segui-Gomez, Maria; Arbogast, Kristy; Augenstein, Jeffrey; Digges, Kennerly H.

2003-01-01

SUMMARY In February 2000, a group of highway safety organizations sent a letter to the Secretary of the U.S. Department of Transportation expressing concern about a possible return to the 30-mph rigid barrier test using unbelted dummies previously required by Federal Motor Vehicle Safety Standard (FMVSS) 208. The letter asked the National Highway Traffic Safety Administration (NHTSA) to expedite data collection of the real-world crash experience of airbag-equipped vehicles certified to the 30-mph sled test using unbelted dummies because of suggestions that depowered airbags may not provide the same level of protection, particularly to larger, unbelted occupants. For the same reason, the letter also recommended that the auto industry commit funding for additional data collection and to establish a panel of experts to evaluate the data. In response, the Alliance of Automobile Manufacturers (Alliance) committed to funding a 3-year program to be managed by an independent third party. A panel of experts consisting of representatives from the highway safety research community, the National Transportation Safety Board, academia, medical institutions, and the insurance industry was established as the Blue Ribbon Panel (BRP) for Evaluation of Depowered and Advanced Airbags and met for the first time in February 2001. The BRP also includes representatives from NHTSA and the automobile industry who participate as observers. The BRP held its first public meeting in April 2003 to provide an update of its activities and to summarize the real-world evidence on the performance of depowered airbags. This AAAM session will provide a brief summary of the public meeting. PMID:12941215

Misuse of Booster Cushions – An Observation Study of Children’s Performance during Buckling Up

PubMed Central

Osvalder, Anna-Lisa; Bohman, Katarina

2008-01-01

Booster cushions are effective tools to protect children from injuries in car crashes, but there remains a large amount of misuse. The aim of this study was to assess potential misuse of booster cushions in an observational laboratory study, and to identify whether booster cushion design, age or clothing had any effect. 130 Swedish children from the ages of 4–12 years participated. Each child buckled up on an integrated and on an aftermarket booster cushion in the rear seat. The older children also buckled up with seat belt only. Interviews, observations and body measurements were performed. Time to buckle up and amount of belt slack were registered. Photographs were taken to document misuse. Results showed that 77% failed to perform correct belt routing on the aftermarket cushion, independent of age, although they were familiar with this system. The misuse rate for the integrated cushion was only 4%. No misuse was found for seat belt only. Few children tightened the belt. The belt slack increased when wearing winter jackets. This indicates the importance of adding pretensioners to the rear seat. Sled tests with HIII&TNO 6y dummies were also performed for the most frequent misuse situations found. The main conclusion is that an integrated booster cushion has many advantages compared to an aftermarket cushion regarding both safety and comfort. It is easy and quick to handle, has few possibilities for misuse, has an intuitive design, the buckling up sequence is equal to buckling up with an ordinary seat belt, and younger children can buckle up correctly. PMID:19026222

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.

Head-first impact with head protrusion causes noncontiguous injuries of the cadaveric cervical spine.

PubMed

Ivancic, Paul C

2012-09-01

To simulate horizontally aligned head-first impacts with initial head protrusion using a human cadaveric neck model and to determine biomechanical responses, injuries, and injury severity. Head-first impacts with initial head protrusion were simulated at 2.4 m/s using a human cadaver neck model (n = 10) mounted horizontally to a torso-equivalent mass on a sled and carrying a surrogate head. Macroscopic neck injuries were determined, and ligamentous injuries were quantified using fluoroscopy and visual inspection after the impacts. Representative time-history responses for injured specimens were determined during impact using load cell data and analyses of high-speed video. Biomechanics research laboratory. Cervical spines of 10 human cadavers. Injury severity at the middle and lower cervical spine was statistically compared using a 2-sample t test (P < 0.05). Neck buckling consisted of hyperflexion at C6/7 and C7/T1 and hyperextension at superior spinal levels. Noncontiguous neck injuries included forward dislocation at C7/T1, spinous process fracture and compression-extension injuries at the middle cervical spine, and atlas and odontoid fractures. Ligamentous injury severity at C7/T1 was significantly greater than at the middle cervical spine. Distinct injury mechanisms were observed throughout the neck, consisting of extension-compression and posterior shear at the upper and middle cervical spine and flexion-compression and anterior shear at C6/7 and C7/T1. Our experimental results highlight the importance of clinical awareness of potential noncontiguous cervical spine injuries due to head-first sports impacts.

Management of fluid mud in estuaries, bays, and lakes. II: Measurement, modeling, and management

USGS Publications Warehouse

McAnally, W.H.; Teeter, A.; Schoellhamer, David H.; Friedrichs, C.; Hamilton, D.; Hayter, E.; Shrestha, P.; Rodriguez, H.; Sheremet, A.; Kirby, R.

2007-01-01

Techniques for measurement, modeling, and management of fluid mud are available, but research is needed to improve them. Fluid mud can be difficult to detect, measure, or sample, which has led to new instruments and new ways of using existing instruments. Multifrequency acoustic fathometers sense neither density nor viscosity and are, therefore, unreliable in measuring fluid mud. Nuclear density probes, towed sleds, seismic, and drop probes equipped with density meters offer the potential for accurate measurements. Numerical modeling of fluid mud requires solving governing equations for flow velocity, density, pressure, salinity, water surface, plus sediment submodels. A number of such models exist in one-, two-, and three-dimensional form, but they rely on empirical relationships that require substantial site-specific validation to observations. Management of fluid mud techniques can be classified as those that accomplish: Source control, formation control, and removal. Nautical depth, a fourth category, defines the channel bottom as a specific fluid mud density or alternative parameter as safe for navigation. Source control includes watershed management measures to keep fine sediment out of waterways and in-water measures such as structures and traps. Formation control methods include streamlined channels and structures plus other measures to reduce flocculation and structures that train currents. Removal methods include the traditional dredging and transport of dredged material plus agitation that contributes to formation control and/or nautical depth. Conditioning of fluid mud by dredging and aerating offers the possibility of improved navigability. Two examples—the Atchafalaya Bar Channel and Savannah Harbor—illustrate the use of measurements and management of fluid mud.

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.

Analysis of the stability of PTW riders in autonomous braking scenarios.

PubMed

Symeonidis, Ioannis; Kavadarli, Gueven; Erich, Schuller; Graw, Matthias; Peldschus, Steffen

2012-11-01

While fatalities of car occupants in the EU decreased remarkably over the last decade, Powered Two Wheelers (PTWs) fatalities still increase following the increase of PTW ownership. Autonomous braking systems have been implemented in several types of vehicles and are presently addressed by research in the field of PTWs. A major concern in this context is the rider stability. Experiments with volunteers were performed in order to find out whether autonomous braking for PTWs will produce a greater instability of the rider in comparison to manual braking. The PTW's braking conditions were simulated in a laboratory with a motorcycle mock-up mounted on a sled, which was accelerated with an average of 0.35 g. The motion of the rider was captured in autonomous braking scenarios with and without pre-warning as well as in manual braking scenarios. No significant differences between the scenarios were found with respect to maximum forward displacement of the volunteer's torso and head (p<0.05). By performing clustering analysis on two kinematic parameters, two different strategies of the volunteers were identified. They were not related to the braking scenarios. A relation of the clusters with the initial posture represented by the elbow angle was revealed (p<0.05). It is concluded that autonomous braking at low deceleration will not cause significant instabilities of the rider in comparison to manual braking in idealized laboratory conditions. Based on this, further research into the development and implementation of autonomous braking systems for PTWs, e.g. by extensive riding tests, seems valuable. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Influence of Active Muscle Contribution on the Injury Response of Restrained Car Occupants

PubMed Central

Bose, Dipan; Crandall, Jeff R.

2008-01-01

Optimal performance of adaptive restraint systems requires an accurate assessment of occupant parameters including physical properties and pre-collision behavior of the occupant. Muscle bracing, one of the key reflexive actions adopted by car occupants to mitigate the severity of an impending collision, is ignored in restraint designing since conventional human surrogate tools used for injury assessment due to collision loading provide limited insight into this effect. This study is aimed at evaluating the effect of pre-collision muscle bracing on the injury outcome of an occupant using a simplified numerical musculoskeletal model. The activation levels for 12 major muscle groups loading the ankle, knee, hip and elbow joints, were determined using an optimization routine with data collected from previously reported volunteer sled tests. A whole body injury metric, weighted to the severity of injury and the injured body region, was used to evaluate the potential risk of injuries estimated for different levels of bracing. The musculoskeletal model was further used to determine the requirements on the restraint system properties to minimize overall injuries for an occupant in a relaxed and a braced condition. Significant variation was observed in the load-limiting value and pre-tensioner firing time, as the restraint properties were optimized to account for the bracing behavior. The results of the study provide a framework for improving the performance of adaptive restraint systems, currently designed for passive anthropometric tests devices, by taking into account realistic response of the occupant involved in a collision. PMID:19026223

Spacelab

NASA Image and Video Library

1992-01-01

Astronaut Ulf Merbold on the stationary seat of the mini-sled, stares into an umbrella-shaped rotating dome with colored dots. Astronaut Merbold, assisted by astronaut David Hilmer, are conducting the Visual Simulator Experiment, a space physiology experiment. The Visual Stimulator Experiment measures the relative importance of visual and vestibular information in determining body orientation. When a person looks at a rotating visual field, a false sensation of self-rotation, called circularvection, results. In weightlessness, circularvection should increase immediately and may continue to increase as the nervous system comes to rely more on visual than vestibular cues. As Astronaut Merbold stares into the rotating dome with a pattern of colored dots and its interior, he turns a knob to indicate his perception of body rotation. The strength of circularvection is calculated by comparing signals from the dome and the knob. The greater the false sense of circularvection, the more the subject is relying on visual information instead of otolith information. The IML-1 mission was the first in a series of Shuttle flights dedicated to fundamental materials and life sciences research with the international partners. The participating space agencies included: NASA, the 14-nation European Space Agency (ESA), the Canadian Space Agency (CSA), the French National Center of Space Studies (CNES), the German Space Agency and the German Aerospace Research Establishment (DAR/DLR), and the National Space Development Agency of Japan (NASDA). Managed by the Marshall Space Flight Center, IML-1 was launched on January 22, 1992 aboard the Space Shuttle Orbiter Discovery (STS-42 mission).

Acute Physiological Responses to Strongman Training Compared to Traditional Strength Training.

PubMed

Harris, Nigel K; Woulfe, Colm J; Wood, Matthew R; Dulson, Deborah K; Gluchowski, Ashley K; Keogh, Justin B

2016-05-01

Strongman training (ST) has become an increasingly popular modality, but data on physiological responses are limited. This study sought to determine physiological responses to an ST session compared to a traditional strength exercise training (RST) session. Ten healthy men (23.6 ± 27.5 years, 85.8 ± 10.3 kg) volunteered in a crossover design, where all participants performed an ST session, an RST session, and a resting session within 7 days apart. The ST consisted of sled drag, farmer's walk, 1 arm dumbbell clean and press, and tire flip at loads eliciting approximately 30 seconds of near maximal effort per set. The RST consisted of squat, deadlift, bench press, and power clean, progressing to 75% of 1 repetition maximum. Sessions were equated for approximate total set duration. Blood lactate and salivary testosterone were recorded immediately before and after training sessions. Heart rate, caloric expenditure, and substrate utilization were measured throughout the resting session, both training protocols and for 80 minutes after training sessions. Analyses were conducted to determine differences in physiological responses within and between protocols. No significant changes in testosterone occurred at any time point for either session. Lactate increased significantly immediately after both sessions. Heart rate, caloric expenditure, and substrate utilization were all elevated significantly during ST and RST. Heart rate and fat expenditure were significantly elevated compared to resting in both sessions' recovery periods; calorie and carbohydrate expenditures were not. Compared to RST, ST represents an equivalent physiological stimulus on key parameters indicative of potential training-induced adaptive responses. Such adaptations could conceivably include cardiovascular conditioning.

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.

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.

Development and validation of age-dependent FE human models of a mid-sized male thorax.

PubMed

El-Jawahri, Raed E; Laituri, Tony R; Ruan, Jesse S; Rouhana, Stephen W; Barbat, Saeed D

2010-11-01

The increasing number of people over 65 years old (YO) is an important research topic in the area of impact biomechanics, and finite element (FE) modeling can provide valuable support for related research. There were three objectives of this study: (1) Estimation of the representative age of the previously-documented Ford Human Body Model (FHBM) -- an FE model which approximates the geometry and mass of a mid-sized male, (2) Development of FE models representing two additional ages, and (3) Validation of the resulting three models to the extent possible with respect to available physical tests. Specifically, the geometry of the model was compared to published data relating rib angles to age, and the mechanical properties of different simulated tissues were compared to a number of published aging functions. The FHBM was determined to represent a 53-59 YO mid-sized male. The aforementioned aging functions were used to develop FE models representing two additional ages: 35 and 75 YO. The rib model was validated against human rib specimens and whole rib tests, under different loading conditions, with and without modeled fracture. In addition, the resulting three age-dependent models were validated by simulating cadaveric tests of blunt and sled impacts. The responses of the models, in general, were within the cadaveric response corridors. When compared to peak responses from individual cadavers similar in size and age to the age-dependent models, some responses were within one standard deviation of the test data. All the other responses, but one, were within two standard deviations.

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.

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.

Water requirements of canine athletes during multi-day exercise.

PubMed

Stephens-Brown, Lara; Davis, Michael

2018-03-23

Exercise increases water requirements, but there is little information regarding water loss in dogs performing multi-day exercise OBJECTIVES: Quantify the daily water turnover of working dogs during multi-day exercise and establish the suitability of SC administration of tracer to determine water turnover. Fifteen privately owned Labrador retrievers trained for explosive detection duties and 16 privately owned Alaskan Huskies conditioned for mid-distance racing. All dogs received 0.3 g D 2 O/kg body weight by IV infusion, gavage, or SC injection before the start of a multi-day exercise challenge. Explosive detection dogs conducted 5 days of simulated off-leash explosive detection activity. Alaskan sled dogs completed a mid-distance stage race totaling 222 km in 2 days. Total body water (TBW) and daily water turnover were calculated using both indicator dilution and elimination regression techniques. Total body water (% of body weight) varied from 60% ± 8.6% in minimally conditioned Labrador retrievers to 74% ± 4.5% in highly conditioned Labrador retrievers. Daily water turnover was as high as 45% of TBW during exercise in cold conditions. There was no effect of sex or speed on daily water turnover. There was good agreement between results calculated using the indicator dilution approach and those calculated using a semilog linear regression approach when indicator isotope was administered IV or SC. Water requirements are influenced primarily by the amount of work done. SC administration of isotope-labeled water offers a simple and accurate alternative method for metabolic studies. © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Effects of turf and cleat footwear on plantar load distributions in adolescent American football players during resisted pushing.

PubMed

Taylor, Jeffrey B; Nguyen, Anh-Dung; Griffin, Janet R; Ford, Kevin R

2018-06-01

Metatarsal and midfoot injuries are common in American football. Footwear design may influence injury rates by altering plantar foot loading patterns in these regions. The purpose of this study was to determine the effect of cleat design on in-shoe plantar foot loading during a football-specific, resisted pushing task. Twenty competitive football players (age 14.7 ± 1.8 years, height 1.72 ± 0.10 m, and mass 71.8 ± 26.9 kg) completed three trials of pushing a weighted sled at maximal effort in a standard shoe (CLEAT) and artificial turf-specific shoe (TURF), with flexible in-shoe force measuring insoles. Repeated measures ANOVAs identified mean differences in maximum force and relative load under all regions of the foot. Results showed higher forces in the CLEAT under the medial (p < 0.001) and lateral (p = 0.004) midfoot, central (p = 0.007) and lateral (p < 0.001) forefoot, and lesser toes (p = 0.01), but lower forces in the hallux (p = 0.02) compared to the TURF shoe. Additionally, relative loading was higher in the CLEAT under the medial (p < 0.001) and lateral (p = 0.002) midfoot and lateral (p < 0.001) forefoot, but lower in the medial forefoot (p = 0.006) and hallux (p < 0.001) compared to the TURF shoe. The two shoes elicited distinct plantar loading profiles and may influence shoe selection decisions during injury prevention or rehabilitation practices.

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.

WHIPS seat and occupant motions during simulated rear crashes.

PubMed

Xiao, Ming; Ivancic, Paul C

2010-10-01

Objectives of this study were to investigate the motions of Volvo's Whiplash Protection System (WHIPS) seat and occupant during simulated rear crashes of a human model of the neck (HUMON). HUMON consisted of a human neck specimen (n = 6) mounted to the torso of BioRID II and carrying an anthropometric head stabilized with muscle force replication. HUMON was seated and secured in a 2005 Volvo XC90 minivan seat that included WHIPS and a fixed head restraint. Rear crashes of 9.9 g (ΔV 9.2 kph), 12.0 g (ΔV 11.4 kph), and 13.3 g (ΔV 13.4 kph) were simulated and WHIPS and occupant motions were monitored. Linear regression analyses (P < .05) were used to determine relationships between WHIPS and occupant motion peaks using data from all crashes combined. WHIPS motions consisted of simultaneous rearward and downward translations and extension of the seatback and plastic deformation of the bilateral WHIPS energy-absorbing components. Peak WHIPS motions were linearly correlated only with peak rearward occupant translations. Less rearward pelvis translation was required to cause WHIPS activation as compared to T1 translation. WHIPS reduced peak T1 horizontal acceleration by 39 percent compared to sled acceleration. This was within the range previously reported for WHIPS, between 30 and 60 percent, but higher than the 16 percent reduction previously reported due to active head restraint. Absorption of crash energy occurred during the initial 75 ms and the onset of head support occurred at 114 ms. Differential head-torso motions occurred prior to and during head support, indicating the potential for neck injury even with WHIPS.

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.

The influence of light hypothenar contact during a reaching movement on the centre of pressure (COP) forward displacement.

PubMed

Rugelj, Darja; Trontelj, Jože V; Strojnik, Vojko

2013-01-01

The purpose of this study was to evaluate the effect of additional light hand contact (F<1 N) in the region of the hypothenar eminence on forward movement of the center of pressure (COP) and dominant hand. Subjects sled their hypothenar eminence on a vertically-oriented pressure sensitive board while reaching forward beyond their arm length. In the two separate experiments forty nine healthy, college-aged volunteers participated in the study. Thirty subjects (mean age of 22.2±2.4 years, 6 male and 24 female) participated in the experiment on level ground and nineteen subjects (22±2.6 years, 5 male and 14 female) in the experiment on an elevated surface. The forward displacement of the COP was significantly larger (p = 0.002) when subjects were allowed to slide with the hand as compared to no contact when the activity occurred on level ground (84±10 mm and 79±11 mm, respectively), and on a one meter elevated surface (71±17 mm and 65±21 mm, respectively). The maximal forward reach of the dominant hand was significantly greater when subjects were allowed to slide with the hypothenar eminence as compared to the no contact condition on the level ground (336±35 mm and 344±38 mm, respectively, p<0.02), and on the one meter elevated surface (298±58 mm and 307±58 mm, respectively, p<0.01). This data indicate that subjects were able to use additional haptic information from the hypothenar region to bring their COP and dominant hand further forward while standing on level ground as well as on a one m elevated surface.

Experimental Study of Thoracoabdominal Injuries Suffered from Caudocephalad Impacts Using Pigs

PubMed Central

Guan, Sishu; Liao, Zhikang; Xiang, Hongyi; Zhu, Xiyan; Wang, Zhong; Lai, Xinan

2018-01-01

To know the caudocephalad impact- (CCI-) induced injuries more clearly, 21 adult minipigs, randomly divided into three groups: control group (n = 3), group I (n = 9), and group II (n = 9), were used to perform the CCI experiments on a modified deceleration sled. Configured impact velocity was 0 m/s in the control group, 8 m/s in group I, and 11 m/s in group II. The kinematics and mechanical responses of the subjects were recorded and investigated. The functional change examination and the autopsies were carried out, with which the injuries were evaluated from the Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS). The subjects in group I and group II experienced the caudocephalad loading at the peak pelvic accelerations of 108.92 ± 58.87 g and 139.13 g ± 78.54 g, with the peak abdomen pressures, 41.24 ± 16.89 kPa and 63.61 ± 65.83 kPa, respectively. The injuries of the spleen, lung, heart, and spine were detected frequently among the tested subjects. The maximal AIS (MAIS) of chest injuries was 4 in group I and 5 in group II, while both the MAIS of abdomen injuries in group I and group II were 5. The ISS in group II was 52.71 ± 6.13, significantly higher than in group I, 26.67 ± 5.02 (p < 0.05). The thoracoabdomen CCI injuries and the mechanical response addressed presently may be useful to conduct both the prevention studies against military or civilian injuries. PMID:29861783

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

Breath-Hold Diving.

PubMed

Fitz-Clarke, John R

2018-03-25

Breath-hold diving is practiced by recreational divers, seafood divers, military divers, and competitive athletes. It involves highly integrated physiology and extreme responses. This article reviews human breath-hold diving physiology beginning with an historical overview followed by a summary of foundational research and a survey of some contemporary issues. Immersion and cardiovascular adjustments promote a blood shift into the heart and chest vasculature. Autonomic responses include diving bradycardia, peripheral vasoconstriction, and splenic contraction, which help conserve oxygen. Competitive divers use a technique of lung hyperinflation that raises initial volume and airway pressure to facilitate longer apnea times and greater depths. Gas compression at depth leads to sequential alveolar collapse. Airway pressure decreases with depth and becomes negative relative to ambient due to limited chest compliance at low lung volumes, raising the risk of pulmonary injury called "squeeze," characterized by postdive coughing, wheezing, and hemoptysis. Hypoxia and hypercapnia influence the terminal breakpoint beyond which voluntary apnea cannot be sustained. Ascent blackout due to hypoxia is a danger during long breath-holds, and has become common amongst high-level competitors who can suppress their urge to breathe. Decompression sickness due to nitrogen accumulation causing bubble formation can occur after multiple repetitive dives, or after single deep dives during depth record attempts. Humans experience responses similar to those seen in diving mammals, but to a lesser degree. The deepest sled-assisted breath-hold dive was to 214 m. Factors that might determine ultimate human depth capabilities are discussed. © 2018 American Physiological Society. Compr Physiol 8:585-630, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

Habitat associations and distribution of the hyperbenthic shrimp, Nauticaris marionis, around the sub-Antarctic Prince Edward Islands

NASA Astrophysics Data System (ADS)

Haley, Craig; von der Meden, Charles; Atkinson, Lara; Reed, Cecile

2017-09-01

The association of organisms with particular habitats and habitat-forming organisms, can strongly influence species distributions, interactions and wider ecosystem services. At the sub-Antarctic Prince Edward Islands, the caridean shrimp Nauticaris marionis is a principal part of the benthic ecosystem, occurring between ca. 50 m and 600 m. Its role as a trophic link between the primary productivity and higher predators is established, but little is understood of its in situ habitat usage and associations or of how these structure patterns of abundance. We investigated these aspects directly using a benthic camera sled, sampling 27 stations between 50 m and 500 m. Substratum type was characterised, and estimates of percentage cover of the 13 main groups of habitat-forming epibenthic taxa were made, alongside absolute counts of N. marionis within 'digital quadrats' drawn from 300 m transects. The distribution of N. marionis was influenced by depth, substratum type and overall biogenic cover, being limited to habitats between 50 and 160 m depth on mud or gravel substrata only, and having > 50% biogenic cover. The presence/absence of N. marionis related to significantly different epibenthic assemblages (termed biogenic habitats), but this effect was contingent on depth. Likewise, densities of N. marionis were significantly affected by biogenic habitat type, identifying an association with two biogenic habitat groups, one dominated by red-algae, the other by structurally complex bryozoan species. These associations likely relate to the structural complexity of the two habitat groups, rather than the specific taxa involved. The apparent absence of N. marionis at depths > 160 m contrasts with earlier records and poses questions about the trophic importance of the shrimp in deeper habitats.

Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z 2-4 as probed by multi-J CO lines

NASA Astrophysics Data System (ADS)

Yang, C.; Omont, A.; Beelen, A.; Gao, Y.; van der Werf, P.; Gavazzi, R.; Zhang, Z.-Y.; Ivison, R.; Lehnert, M.; Liu, D.; Oteo, I.; González-Alfonso, E.; Dannerbauer, H.; Cox, P.; Krips, M.; Neri, R.; Riechers, D.; Baker, A. J.; Michałowski, M. J.; Cooray, A.; Smail, I.

2017-12-01

We present the IRAM-30 m observations of multiple-J CO (Jup mostly from 3 up to 8) and [C I](3P2 → 3P1) ([C I](2-1) hereafter) line emission in a sample of redshift 2-4 submillimeter galaxies (SMGs). These SMGs are selected among the brightest-lensed galaxies discovered in the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS). Forty-seven CO lines and 7 [C I](2-1) lines have been detected in 15 lensed SMGs. A non-negligible effect of differential lensing is found for the CO emission lines, which could have caused significant underestimations of the linewidths, and hence of the dynamical masses. The CO spectral line energy distributions (SLEDs), peaking around Jup 5-7, are found to be similar to those of the local starburst-dominated ultra-luminous infrared galaxies and of the previously studied SMGs. After correcting for lensing amplification, we derived the global properties of the bulk of molecular gas in the SMGs using non-LTE radiative transfer modelling, such as the molecular gas density nH2 102.5-104.1 cm-3 and the kinetic temperature Tk 20-750 K. The gas thermal pressure Pth ranging from 105 K cm-3 to 106 K cm-3 is found to be correlated with star formation efficiency. Further decomposing the CO SLEDs into two excitation components, we find a low-excitation component with nH2 102.8-104.6 cm-3 and Tk 20-30 K, which is less correlated with star formation, and a high-excitation one (nH2 102.7-104.2 cm-3, Tk 60-400 K) which is tightly related to the on-going star-forming activity. Additionally, tight linear correlations between the far-infrared and CO line luminosities have been confirmed for the Jup ≥ 5 CO lines of these SMGs, implying that these CO lines are good tracers of star formation. The [C I](2-1) lines follow the tight linear correlation between the luminosities of the [C I](2-1) and the CO(1-0) line found in local starbursts, indicating that [C I] lines could serve as good total molecular gas mass tracers for high-redshift SMGs as well

Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish.

PubMed

Letcher, Robert J; Bustnes, Jan Ove; Dietz, Rune; Jenssen, Bjørn M; Jørgensen, Even H; Sonne, Christian; Verreault, Jonathan; Vijayan, Mathilakath M; Gabrielsen, Geir W

2010-07-01

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely

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.

Influence of Vibrotactile Feedback on Controlling Tilt Motion After Spaceflight

NASA Technical Reports Server (NTRS)

Wood, S. J.; Rupert, A. H.; Vanya, R. D.; Esteves, J. T.; Clement, G.

2011-01-01

We hypothesize that adaptive changes in how inertial cues from the vestibular system are integrated with other sensory information leads to perceptual disturbances and impaired manual control following transitions between gravity environments. The primary goals of this ongoing post-flight investigation are to quantify decrements in manual control of tilt motion following short-duration spaceflight and to evaluate vibrotactile feedback of tilt as a sensorimotor countermeasure. METHODS. Data is currently being collected on 9 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s, <20 cm radius) in a darkened room is utilized to elicit otolith reflexes in the lateral plane without concordant canal or visual cues. A Tilt-Translation Sled (TTS) is capable of synchronizing pitch tilt with fore-aft translation to align the resultant gravitoinertial vector with the longitudinal body axis, thereby eliciting canal reflexes without concordant otolith or visual cues. A simple 4 tactor system was implemented to provide feedback when tilt position exceeded predetermined levels in either device. Closed-loop nulling tasks are performed during random tilt steps or sum-of-sines (TTS only) with and without vibrotactile feedback of chair position. RESULTS. On landing day the manual control performance without vibrotactile feedback was reduced by >30% based on the gain or the amount of tilt disturbance successfully nulled. Manual control performance tended to return to baseline levels within 1-2 days following landing. Root-mean-square position error and tilt velocity were significantly reduced with vibrotactile feedback. CONCLUSIONS. These preliminary results are consistent with our hypothesis that adaptive changes in vestibular processing corresponds to reduced manual control performance following G-transitions. A simple vibrotactile prosthesis improves the ability to null out tilt motion within a

Comparing Geophysical Methods for Determining the Thickness of Arctic Sea Ice: Is There a Correlation Between Thickness and Surface Temperature?

NASA Astrophysics Data System (ADS)

Robertson, R.; Bowman, T.; Eagle, J. L.; Fisher, L.; Mankowski, K.; McGrady, N.; Schrecongost, N.; Voll, H.; Zulfiqar, A.; Herman, R. B.

2016-12-01

Several small geophysical surveys were conducted on the Chukchi Sea ice just offshore from the Naval Arctic Research Laboratory near Barrow, Alaska, in March, 2016. The goal was to investigate a possible correlation between the surface temperature and the thickness of the sea ice, as well as to test a potential new method for more accurately determining ice thickness. Surveys were conducted using a capacitively coupled resistivity array, a custom built thermal sensor array sled, ground penetrating radar (GPR), and an ice drill. The thermal sensor array was based on an Arduino microcontroller. It used an infrared (IR) sensor to determine surface temperature, and thermistor-based sensors to determine vertical air temperatures at 6 evenly spaced heights up to a maximum of 1.5 meters. Surface temperature (IR) data show possible correlations with ice drill, resistivity, and GPR data. The vertical air sensors showed almost no variation for any survey line which we postulate is due to the constant wind during each survey. Ice drill data show ice thickness along one 200 meter line varied from 79-95 cm, with an average of 87 cm. The thickness appears to be inversely correlated to surface temperatures. Resistivity and IR data both showed abrupt changes when crossing from the shore to the sea ice along a 400 meter line. GPR and IR data showed similar changes along a separate 900 meter line, suggesting that surface temperature and subsurface composition are related. Resistivity data were obtained in two locations by using the array in an expanding dipole-dipole configuration with 2.5 meter dipoles. The depth to the ice/water boundary was calculated using a "cumulative resistivity" plot and matched the depths obtained via the ice drill to within 2%. This has initiated work to develop a microcontroller-based resistivity array specialized for thickness measurements of thin ice.

Field Operations For The "Intelligent River" Observation System: A Basin-wide Water Quality Observation System In The Savannah River Basin And Platform Supporting Related Diverse Initiatives.

NASA Astrophysics Data System (ADS)

Sutton, A.; Koons, M.; O'Brien-Gayes, P.; Moorer, R.; Hallstrom, J.; Post, C.; Gayes, P. T.

2017-12-01

The Intelligent River (IR) initiative is an NSF sponsored study developing new data management technology for a range of basin-scale applications. The technology developed by Florida Atlantic and Clemson University established a network of real-time reporting water quality sondes; from the mountains to the estuary of the Savannah River basin. Coastal Carolina University led the field operations campaign. Ancillary studies, student projects and initiatives benefitted from the associated instrumentation, infrastructure and operational support of the IR program. This provided a vehicle for students to participate in fieldwork across the watershed and pursue individual interests. Student projects included: 1) a Multibeam sonar survey investigating channel morphology in the area of an IR sensor station and 2) field tests of developing techniques for acquiring and assimilating flood velocity data into model systems associated with a separate NSF Rapid award. The multibeam survey within the lower Savannah basin exhibited a range of complexity in bathymetry, bedforms and bottom habitat in the vicinity of one of the water quality stations. The complex morphology and bottom habitat reflect complex flow patterns, localized areas of depositional and erosive tendencies providing a valuable context for considering point-source water quality time series. Micro- Lagrangian drifters developed by ISENSE at Florida Atlantic University, a sled mounted ADCP, and particle tracking from imagery collected by a photogrammetric drone were tested and used to develop methodology for establishing velocity, direction and discharge levels to validate, initialize and assimilate data into advance models systems during future flood events. The prospect of expanding wide scale observing systems can serve as a platform to integrate small and large-scale cooperative studies across disciplines as well as basic and applied research interests. Such initiatives provide opportunities for embedded education

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.

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.

Hard-bottom bathyal habitats and keystone epibenthic species on Le Danois Bank (Cantabrian Sea)

NASA Astrophysics Data System (ADS)

Sánchez, F.; Rodríguez Basalo, A.; García-Alegre, A.; Gómez-Ballesteros, M.

2017-12-01

"El Cachucho" Marine Protected Area (MPA), which comprises Le Danois Bank and its intraslope basin, was included during 2008 in the Nature 2000 network mainly because of the presence of the habitat "1170 Reefs" according to the EU Habitat Directive. To review the effectiveness of existing management measures, several activities aimed at characterizing the most structurally complex hard-bottom habitats were planned and carried out during the ESMAREC 0514 survey. For identification of these habitats, several transects using the photogrammetric towed sled Politolana were carried out on Le Danois Bank, in the depth range between 427 and 1379 m, searching for the sea beds with higher values of slope and backscatter. Photogrammetric techniques were used for image scaling, so we could determine the surface areas of different substrata types (facies) and their species densities. A total area of 28,762 m2 was analyzed in the still images of 23 transects, verifying that 85% of the substrata of our study area are occupied by 4 different facies: Bedrock, bedrock with mixed sediments, mixed sediments with pebbles and boulders, and mixed sediments. Acoustic data and ground-truth visual data were combined to evaluate distinctive benthic scenarios. The relative abundances of the 123 epibenthic species identified by image analyses show that the most abundant are sponges (29%), cnidarians (26%), crustaceans (26%) and echinoderms (14%), i.e. mostly sessile species or those with low mobility. The keystone species of the "1170 Reefs" habitat are 3 cnidarians: Callogorgia verticillata, Paramuricea cf. placomus and Dendrophyllia cornigera, and 3 sponges, Asconema setubalense, Geodia msp.1 and Phakellia robusta. Eight new habitats (biotopes) have been identified on Le Danois Bank, six of which occur on the hard bottoms, with depth, substratum, BPI (Bathymetric Position Index) and slope as determining environmental variables that explain their spatial distributions.

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.

Biomechanical analyses of whiplash injuries using an experimental model.

PubMed

Yoganandan, Narayan; Pintar, Frank A; Cusick, Joseph F

2002-09-01

Neck pain and headaches are the two most common symptoms of whiplash. The working hypothesis is that pain originates from excessive motions in the upper and lower cervical segments. The research design used an intact human cadaver head-neck complex as an experimental model. The intact head-neck preparation was fixed at the thoracic end with the head unconstrained. Retroreflective targets were placed on the mastoid process, anterior regions of the vertebral bodies, and lateral masses at every spinal level. Whiplash loading was delivered using a mini-sled pendulum device. A six-axis load cell and an accelerometer were attached to the inferior fixation of the specimen. High-speed video cameras were used to obtain the kinematics. During the initial stages of loading, a transient decoupling of the head occurs with respect to the neck exhibiting a lag of the cranium. The upper cervical spine-head undergoes local flexion concomitant with a lag of the head while the lower column is in local extension. This establishes a reverse curvature to the head-neck complex. With continuing application of whiplash loading, the inertia of the head catches up with the neck. Later, the entire head-neck complex is under an extension mode with a single extension curvature. The lower cervical facet joint kinematics demonstrates varying local compression and sliding. While the anterior- and posterior-most regions of the facet joint slide, the posterior-most region of the joint compresses more than the anterior-most region. These varying kinematics at the two ends of the facet joint result in a pinching mechanism. Excessive flexion of the posterior upper cervical regions can be correlated to headaches. The pinching mechanism of the facet joints can be correlated to neck pain. The kinematics of the soft tissue-related structures explain the mechanism of these common whiplash associated disorders.

Observation of Snow cover glide on Sub-Alpine Coniferous Forests in Mount Zao, Northeastern Japan

NASA Astrophysics Data System (ADS)

Sasaki, A.; Suzuki, K.

2017-12-01

This is the study to clarify the snow cover glide behavior in the sub-alpine coniferous forests on Mount Zao, Northeastern Japan, in the winter of 2014-2015. We installed the glide-meter which is sled type, and measured the glide motion on the slope of Abies mariesii forest and its surrounding slope. In addition, we observed the air temperature, snow depth, density of snow, and snow temperature to discuss relationship between weather conditions and glide occurrence. The snow cover of the 2014-15 winter started on November 13th and disappeared on April 21st. The maximum snow depth was 242 cm thick, it was recorded at February 1st. The snow cover glide in the surrounding slope was occurred first at February 10th, although maximum snow depth recorded on February 1st. The glide motion in the surrounding slope is continuing and its velocity was 0.4 cm per day. The glide in the surrounding slope stopped at March 16th. The cumulative amount of the glide was 21.1 cm. The snow cover glide in the A. mariesii forest was even later occurred first at February 21st. The glide motion of it was intermittent and extremely small. On sub-alpine zone of Mount Zao, snow cover glide intensity is estimated to be 289 kg/m2 on March when snow water equivalent is maximum. At same period, maximum snow cover glide intensity is estimated to be about 1000 kg/m2 at very steep slopes where the slope angle is about 35 degree. Although potential of snow cover glide is enough high, the snow cover glide is suppressed by stem of A. mariesii trees, in the sub-alpine coniferous forest.

Kinetics of the cervical spine in pediatric and adult volunteers during low speed frontal impacts.

PubMed

Seacrist, Thomas; Arbogast, Kristy B; Maltese, Matthew R; García-Espaňa, J Felipe; Lopez-Valdes, Francisco J; Kent, Richard W; Tanji, Hiromasa; Higuchi, Kazuo; Balasubramanian, Sriram

2012-01-03

Previous research has quantified differences in head and spinal kinematics between children and adults restrained in an automotive-like configuration subjected to low speed dynamic loading. The forces and moments that the cervical spine imposes on the head contribute directly to these age-based kinematic variations. To provide further explanation of the kinematic results, this study compared the upper neck kinetics - including the relative contribution of shear and tension as well as flexion moment - between children (n=20, 6-14 yr) and adults (n=10, 18-30 yr) during low-speed (<4 g, 2.5 m/s) frontal sled tests. The subjects were restrained by a lap and shoulder belt and photo-reflective targets were attached to skeletal landmarks on the head, spine, shoulders, sternum, and legs. A 3D infrared tracking system quantified the position of the targets. Shear force (F(x)), axial force (F(z)), bending moment (M(y)), and head angular acceleration (θ(head)) were computed using inverse dynamics. The method was validated against ATD measured loads. Peak F(z) and θ(head) significantly decreased with increasing age while M(y) significantly increased with increasing age. F(x) significantly increased with age when age was considered as a univariate variable; however when variations in head-to-neck girth ratio and change in velocity were accounted for, this difference as a function of age was not significant. These results provide insight into the relationship between age-based differences in head kinematics and the kinetics of the cervical spine. Such information is valuable for pediatric cervical spine models and when scaling adult-based upper cervical spine tolerance and injury metrics to children. Copyright © 2011 Elsevier Ltd. All rights reserved.

RF pulse compression for future linear colliders

NASA Astrophysics Data System (ADS)

Wilson, Perry B.

1995-07-01

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 to 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-II system) can be used to reduce the klystron peak power by about a factor of two, or alternatively, 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.

Kinematics of pediatric crash dummies seated on vehicle seats with realistic belt geometry.

PubMed

Klinich, Kathleen D; Reed, Matthew P; Ebert, Sheila M; Rupp, Jonathan D

2014-01-01

A series of sled tests was performed using vehicle seats and Hybrid-III 6-year-old (6YO) and 10YO anthropomorphic test devices (ATDs) to explore possibilities for improving occupant protection for children who are not using belt-positioning booster seats. Cushion length was varied from production length of 450 mm to a shorter length of 350 mm. Lap belt geometry was set to rear, mid, and forward anchorage locations that span the range of lap belt angles found in vehicles. Six tests each were performed with the 6YO and 10YO Hybrid III ATDs. One additional test was performed using a booster seat with the 6YO. The ATDs were positioned using an updated version of the University of Michigan Transportation Research Institute (UMTRI) seating procedure that positions the ATD hips further forward with longer seat cushions to reflect the effect of cushion length on posture that has been measured with child volunteers. ATD kinematics were evaluated using peak head excursion, peak knee excursion, the difference between peak head and peak knee excursion, and the maximum torso angle. Shortening the seat cushion improved kinematic outcomes, particularly for the 10YO. Lap belt geometry had a greater effect on kinematics with the longer cushion length, with mid or forward belt geometries producing better kinematics than the rearward belt geometry. The worst kinematics for both ATDs occurred with the long cushion length and rearward lap belt geometry. The improvements in kinematics from shorter cushion length or more forward belt geometry are smaller than those provided by a booster seat. The results show potential benefits in occupant protection from shortening cushion length and increasing lap belt angles, particularly for children the size of the 10YO ATD.

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.

Design and optimization for the occupant restraint system of vehicle based on a single freedom model

NASA Astrophysics Data System (ADS)

Zhang, Junyuan; Ma, Yue; Chen, Chao; Zhang, Yan

2013-05-01

Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand, the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.

Is strength-training frequency a key factor to develop performance adaptations in young elite soccer players?

PubMed

Otero-Esquina, Carlos; de Hoyo Lora, Moisés; Gonzalo-Skok, Óliver; Domínguez-Cobo, Sergio; Sánchez, Hugo

2017-11-01

The aim of this study was to analyse the effects of a combined strength-training programme (full-back squat, YoYo TM leg curl, plyometrics and sled towing exercises) on performance in elite young soccer players and to examine the effects when this training programme was performed one or two days per week. Thirty-six male soccer players (U-17 to U-19) were recruited and assigned to experimental groups (EXP1: 1 s w -1 ; EXP2: 2 s w -1 ) or a control group (CON). Performance was assessed through a countermovement jump (CMJ) test (relative peak power [CMJ PP ] and CMJ height [CMJ H ]), a 20-m linear sprint test with split-times at 10-m, and a change of direction test (V-cut test) 1 week before starting the training programme and also 1 week after performing such training programme. Within-group analysis showed substantial improvements in CMJ variables (ES: 0.39-0.81) and COD (ES: 0.70 and 0.76) in EXP1 and EXP2, while EXP2 also showed substantial enhancements in all linear sprinting tests (ES: 0.43-0.52). Between-group analysis showed substantially greater improvements in CMJ variables (ES: 0.39-0.68) in experimental groups in comparison to CON. Furthermore, EXP2 achieved a substantial better performance in 20-m (ES: 0.48-0.64) than EXP1 and CON. Finally, EXP2 also showed greater enhancements in 10-m (ES: 0.50) and V-cut test (ES: 0.52) than EXP1. In conclusion, the combined strength-training programme improved jumping ability, independently of training frequency, though the achievement of two sessions per week also enhanced sprinting abilities (linear and COD) in young soccer players.

Epidemiology of sports-related injuries in children and youth presenting to Canadian emergency departments from 2007-2010.

PubMed

Fridman, Liraz; Fraser-Thomas, Jessica L; McFaull, Steven R; Macpherson, Alison K

2013-12-23

Although injuries related to sports and recreation represent a significant burden to children and youth, few studies have examined the descriptive epidemiology of sports-related injury since 2005, and some sports such as ringette have not been evaluated to date. The primary purpose of this study was to provide the descriptive epidemiology of sports-related injuries treated in emergency departments for children and youth aged 5 - 19. A retrospective data analysis was performed using data from the Canadian Hospitals Injury Reporting and Prevention Program [CHIRPP] from fiscal years (April - March) 2007/08 to 2009/10. CHIRPP is a computerized information system designed by the Public Health Agency of Canada that collects information about injuries to people evaluated in emergency departments across 11 pediatric hospitals and 5 general hospitals in Canada. Thirteen sports or activities were analyzed (baseball, basketball, cycling, football, ice hockey, lacrosse, ringette, rugby, skiing, sledding, snowboarding, soccer, and volleyball). Descriptive statistics, including frequency by sport, age and sex, as well as the percent of concussions within each sport were calculated. Out of a total of 56, 691 reported sports and recreational injuries, soccer accounted for the largest proportion of injuries with 11,941 reported cases over the 3 year time period. Of these, approximately 30% were fractures. The 10 - 14 year age group reported the greatest proportion of injuries in 10 out of the 13 sports analyzed. In addition, males reported a greater number of overall injuries than females in 11 out of the 13 sports analyzed. The largest percentage of concussions was reported in ringette; these injuries accounted for 17.1% of overall injuries within this sport. Injury prevention programs in Canada should focus on improving evidence-based programs to reduce the burden of injuries in all sports.

The ecology of xenophyophores (Protista) on eastern Pacific seamounts

NASA Astrophysics Data System (ADS)

Levin, Lisa A.; Thomas, Cynthia L.

1988-12-01

Large, agglutinating protozoans of the class Xenophyophorea are the dominant epifaunal organisms on soft and hard substrates of many bathyal seamounts in the eastern Pacific Ocean off Mexico. Observations made with the submersible Alvin and remotely towed camera sleds on 17 seamounts at 31°, 20°, 13° and 10°N revealed more than ten distinct xenophyophore test morphologies. Most of these appear to represent previously undescribed species. Reticulate forms are numerically dominant at 20°, 13° and 10°N. Xenophyophore abundances increase with decreasing latitude, being rare at 30°N, present at densities of 0.1-1.0 m -2 at 20° and 13°N and often exceeding 1.0 m -2 at 10°N, occasionally reaching 10-18 m -2. Highest concentrations are observed on caldera floors near the base of steep caldera walls, at depths between 1700 and 2500 m. Most individuals select sand-size pelagic foraminiferan tests (63-500 μm) and exclude pebble, silt and clay-size particles for test construction. Xenophyophore on seamounts modify the structure of metazoan communities and may play a role in maintenance of infaunal diversity. Twenty-seven xenophyophore tests were found to provide habitat for 16 major macrofaunal taxa (152 individuals) and three meiofaunal taxa (333 individuals). The presence of xenophyophores also enhances the abundance of isopods, tanaids, ophiuroids, nematodes and harpacticoid copepods dwelling in sediments surrounding the tests. Mobile megafauna are attracted to sediment beneath and adjacent to xenophyophores. We suggest that xenophyophores, which are abundant on many topographic features in deep water (e.g. guyots, trenches, canyons and continental slopes), are a functionally important component of deep-sea benthic communities and require further autecological and synecological investigation.

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

Strong Depth-Related Zonation of Megabenthos on a Rocky Continental Margin (∼700–4000 m) off Southern Tasmania, Australia

PubMed Central

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. PMID:24465758

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.

Simulated combined abnormal environment fire calculations for aviation impacts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 firemore » 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

Human Perception of Ambiguous Inertial Motion Cues

NASA Technical Reports Server (NTRS)

Zhang, Guan-Lu

2010-01-01

Human daily activities on Earth involve motions that elicit both tilt and translation components of the head (i.e. gazing and locomotion). With otolith cues alone, tilt and translation can be ambiguous since both motions can potentially displace the otolithic membrane by the same magnitude and direction. Transitions between gravity environments (i.e. Earth, microgravity and lunar) have demonstrated to alter the functions of the vestibular system and exacerbate the ambiguity between tilt and translational motion cues. Symptoms of motion sickness and spatial disorientation can impair human performances during critical mission phases. Specifically, Space Shuttle landing records show that particular cases of tilt-translation illusions have impaired the performance of seasoned commanders. This sensorimotor condition is one of many operational risks that may have dire implications on future human space exploration missions. The neural strategy with which the human central nervous system distinguishes ambiguous inertial motion cues remains the subject of intense research. A prevailing theory in the neuroscience field proposes that the human brain is able to formulate a neural internal model of ambiguous motion cues such that tilt and translation components can be perceptually decomposed in order to elicit the appropriate bodily response. The present work uses this theory, known as the GIF resolution hypothesis, as the framework for experimental hypothesis. Specifically, two novel motion paradigms are employed to validate the neural capacity of ambiguous inertial motion decomposition in ground-based human subjects. The experimental setup involves the Tilt-Translation Sled at Neuroscience Laboratory of NASA JSC. This two degree-of-freedom motion system is able to tilt subjects in the pitch plane and translate the subject along the fore-aft axis. Perception data will be gathered through subject verbal reports. Preliminary analysis of perceptual data does not indicate that

Deflections from two types of Human Surrogates in Oblique Side Impacts

PubMed Central

Yoganandan, Narayan; Pintar, Frank A.

2008-01-01

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

Optimizing the passenger air bag of an adaptive restraint system for multiple size occupants.

PubMed

Bai, Zhonghao; Jiang, Binhui; Zhu, Feng; Cao, Libo

2014-01-01

The development of the adaptive occupant restraint system (AORS) has led to an innovative way to optimize such systems for multiple size occupants. An AORS consists of multiple units such as adaptive air bags, seat belts, etc. During a collision, as a supplemental protective device, air bags can provide constraint force and play a role in dissipating the crash energy of the occupants' head and thorax. This article presents an investigation into an adaptive passenger air bag (PAB). The purpose of this study is to develop a base shape of a PAB for different size occupants using an optimization method. Four typical base shapes of a PAB were designed based on geometric data on the passenger side. Then 4 PAB finite element (FE) models and a validated sled with different size dummy models were developed in MADYMO (TNO, Rijswijk, The Netherlands) to conduct the optimization to obtain the best baseline PAB that would be used in the AORS. The objective functions-that is, the minimum total probability of injuries (∑Pcomb) of the 5th percentile female and 50th and 95th percentile male dummies-were adopted to evaluate the optimal configurations. The injury probability (Pcomb) for each dummy was adopted from the U.S. New Car Assessment Program (US-NCAP). The parameters of the AORS were first optimized for different types of PAB base shapes in a frontal impact. Then, contact time duration and force between the PAB and dummy head/chest were optimized by adjusting the parameters of the PAB, such as the number and position of tethers, lower the Pcomb of the 95th percentile male dummy. According to the optimization results, 4 typical PABs could provide effective protection to 5th and 50th percentile dummies. However, due to the heavy and large torsos of the 95th percentile occupants, the current occupant restraint system does not demonstrate satisfactory protective function, particularly for the thorax.

The California Seafloor Mapping Program — Providing science and geospatial data for California's State Waters

NASA Astrophysics Data System (ADS)

Johnson, S. Y.; Cochrane, G. R.; Golden, N. E.; Dartnell, P.; Hartwell, S. R.; Cochran, S. A.; Watt, J. T.

2017-12-01

The California Seafloor Mapping Program (CSMP) is a collaborative effort to develop comprehensive bathymetric, geologic, and habitat maps and data for California's State Waters, which extend for 1,350 km from the shoreline to 5.6 km offshore. CSMP began in 2007 when the California Ocean Protection Council and NOAA allocated funding for high-resolution bathymetric mapping to support the California Marine Life Protection Act and update nautical charts. Collaboration and support from the USGS and other partners has led to development and dissemination of one of the world's largest seafloor-mapping datasets. CSMP data collection includes: (1) High-resolution bathymetric and backscatter mapping using swath sonar sensors; (2) "Ground-truth" imaging from a sled mounted with video and still cameras; (3) High-resolution seismic-reflection profiling at 1 km line spacing. Processed data are all publicly available. Additionally, 25 USGS map and datasets covering one third of California's coast have been published. Each publication contains 9 to 12 pdf map sheets (1:24,000 scale), an explanatory pamphlet, and a catalog of digital geospatial data layers (about 15 to 25 per map area) with web services. Map sheets display bathymetry, backscatter, perspective views, habitats, groundtruth imagery, seismic profiles, sediment distribution and thickness, and onshore-offshore geology. The CSMP goal is to serve a large constituency, ranging from senior GIS analysts in large agencies, to local governments with limited resources, to non-governmental organizations, the private sector, and concerned citizens. CSMP data and publications provide essential science and data for ocean and coastal management, stimulate and enable research, and raise public education and awareness of coastal and ocean issues. Specific applications include: Delineation and designation of marine protected areas Characterization and modeling of benthic habitats and ecosystems Updating nautical charts Earthquake hazard

Comparative Effects of In-Season Full-Back Squat, Resisted Sprint Training, and Plyometric Training on Explosive Performance in U-19 Elite Soccer Players.

PubMed

de Hoyo, Moises; Gonzalo-Skok, Oliver; Sañudo, Borja; Carrascal, Claudio; Plaza-Armas, Jose R; Camacho-Candil, Fernando; Otero-Esquina, Carlos

2016-02-01

The aim of this study was to analyze the effects of 3 different low/moderate load strength training methods (full-back squat [SQ], resisted sprint with sled towing [RS], and plyometric and specific drills training [PLYO]) on sprinting, jumping, and change of direction (COD) abilities in soccer players. Thirty-two young elite male Spanish soccer players participated in the study. Subjects performed 2 specific strength training sessions per week, in addition to their normal training sessions for 8 weeks. The full-back squat protocol consisted of 2-3 sets × 4-8 repetitions at 40-60% 1 repetition maximum (∼ 1.28-0.98 m · s(-1)). The resisted sprint training was compounded by 6-10 sets × 20-m loaded sprints (12.6% of body mass). The plyometric and specific drills training was based on 1-3 sets × 2-3 repetitions of 8 plyometric and speed/agility exercises. Testing sessions included a countermovement jump (CMJ), a 20-m sprint (10-m split time), a 50-m (30-m split time) sprint, and COD test (i.e., Zig-Zag test). Substantial improvements (likely to almost certainly) in CMJ (effect size [ES]: 0.50-0.57) and 30-50 m (ES: 0.45-0.84) were found in every group in comparison to pretest results. Moreover, players in PLYO and SQ groups also showed substantial enhancements (likely to very likely) in 0-50 m (ES: 0.46-0.60). In addition, 10-20 m was also improved (very likely) in the SQ group (ES: 0.61). Between-group analyses showed that improvements in 10-20 m (ES: 0.57) and 30-50 m (ES: 0.40) were likely greater in the SQ group than in the RS group. Also, 10-20 m (ES: 0.49) was substantially better in the SQ group than in the PLYO group. In conclusion, the present strength training methods used in this study seem to be effective to improve jumping and sprinting abilities, but COD might need other stimulus to achieve positive effects.

Anisotropic modulus stabilisation: strings at LHC scales with micron-sized extra dimensions

NASA Astrophysics Data System (ADS)

Cicoli, M.; Burgess, C. P.; Quevedo, F.

2011-10-01

We construct flux-stabilised Type IIB string compactifications whose extra dimensions have very different sizes, and use these to describe several types of vacua with a TeV string scale. Because we can access regimes where two dimensions are hierarchically larger than the other four, we find examples where two dimensions are micron-sized while the other four are at the weak scale in addition to more standard examples with all six extra dimensions equally large. Besides providing ultraviolet completeness, the phenomenology of these models is richer than vanilla large-dimensional models in several generic ways: ( i) they are supersymmetric, with supersymmetry broken at sub-eV scales in the bulk but only nonlinearly realised in the Standard Model sector, leading to no MSSM superpartners for ordinary particles and many more bulk missing-energy channels, as in supersymmetric large extra dimensions (SLED); ( ii) small cycles in the more complicated extra-dimensional geometry allow some KK states to reside at TeV scales even if all six extra dimensions are nominally much larger; ( iii) a rich spectrum of string and KK states at TeV scales; and ( iv) an equally rich spectrum of very light moduli exist having unusually small (but technically natural) masses, with potentially interesting implications for cosmology and astrophysics that nonetheless evade new-force constraints. The hierarchy problem is solved in these models because the extra-dimensional volume is naturally stabilised at exponentially large values: the extra dimensions are Calabi-Yau geometries with a 4D K3 or T 4-fibration over a 2D base, with moduli stabilised within the well-established LARGE-Volume scenario. The new technical step is the use of poly-instanton corrections to the superpotential (which, unlike for simpler models, are likely to be present on K3 or T 4-fibered Calabi-Yau compactifications) to obtain a large hierarchy between the sizes of different dimensions. For several scenarios we identify

Modeling occupants in far-side impacts.

PubMed

Douglas, Clay; Fildes, Brian; Gibson, Tom

2011-10-01

Far-side impacts are not part of any regulated NCAP, FMVSS, or similar test regime despite accounting for 43 percent of the seriously injured persons and 30 percent of the harm in U.S. side impact crashes. Furthermore, injuries to the head and thorax account for over half of the serious injuries sustained by occupants in far-side crashes. Despite this, there is no regulated or well-accepted anthropomorphic test device (ATD) or computer model available to investigate far-side impacts. As such, this presents an opportunity to assess a computer model that can be used to measure the effect of varying restraint parameters on occupant biomechanics in far-side impacts. This study sets out to demonstrate the modified TASS human facet model's (MOTHMO) capabilities in modeling whole-body response in far-side impacts. MOTHMO's dynamic response was compared to that of postmortem human subjects (PMHS), WorldSID, and Thor-NT in a series of far-side sled tests. The advantages, disadvantages, and differences of using MOTHMO compared to ATDs were highlighted and described in terms of model design and instrumentation. Potential applications and improvements for MOTHMO were also recommended. The results showed that MOTHMO is capable of replicating the seat belt-to-shoulder complex interaction, pelvis impacts, head displacement, neck and shoulder belt loading from inboard mounted belts, and impacts from multiple directions. Overall, the model performed better than Thor-NT and at least as well as WorldSID when compared to PMHS results. Though WorldSID and Thor-NT ATDs were capable of reproducing many of these impact loads, measuring the seat belt-to-shoulder complex interaction and thoracic deflection at multiple sites and directions was less accurately handled. This study demonstrated that MOTHMO is capable of modeling whole-body response in far-side impacts. Furthermore, MOTHMO can be used as a virtual design tool to explore the effect of varying restraint parameters on occupant

Revealing the Physical Properties of GMC Complexes in the Spiral Arms of NGC 6946

NASA Astrophysics Data System (ADS)

Topal, Selçuk; Bayet, Estelle; Bureau, Martin; Walsh, Wilfred; Davis, Timothy A.

2013-03-01

In this study, we probe for the first time the molecular gas physical properties of several star forming regions located in the arms and inter-arms of the spiral galaxy NGC 6946. Combining our observations with additional data found in the literature, we provide in this study the most complete CO ladder ever obtained in these inter-arm and arm regions, i.e. the CO(1-0, 2-1, 3-2, 4-3, 6-5) and 13CO(1-0, 2-1) transitions. For each region studied, we use more precisely the large velocity gradient (LVG) assumption in order to derive the beam-averaged molecular gas physical properties. Namely, we obtained the gas kinetic temperature (i.e. 'best' T K), volume number gas density (i.e. 'best' n(H2)) and CO column density (i.e. 'best' N(CO)) which best reproduce the data for 8 regions investigated. Optical depths were also estimated for a large variety of CO lines in these regions. To identify the best values found, we used two complementary theoretical approaches when comparing the model predictions with the observations, i.e. the χ2 minimisation and the likelihood. Very different physical conditions for the molecular gas from a region to another have been obtained: T K ranges from 10 to 250 K, n(H2) ranges from 102.3 to 107.0 cm-3 and N(CO) ranges from 1015.0 to 1019.3 cm-2 among the arm and inter-arm regions. For each region probed, we also published for the first time the CO spectral line energy distribution (SLED) from CO(1-0) to CO(10-9) for this galaxy, mixing observations and model predictions which provide an essential insight for future follow-up observational programmes. Finally, in this work, we discuss the physical properties we obtained for each region in relation with the presence of young stellar population characteristics such as supernovae remnants (SNRs), Hi holes, Hii regions.

Dynamic kinematic responses of female volunteers in rear impacts and comparison to previous male volunteer tests.

PubMed

Carlsson, Anna; Linder, Astrid; Davidsson, Johan; Hell, Wolfram; Schick, Sylvia; Svensson, Mats

2011-08-01

The objective was to quantify dynamic responses of 50th percentile females in rear impacts and compare to those from similar tests with males. The results will serve as a basis for future work with models, criteria, and safety systems. A rear impact sled test series with 8 female volunteers was performed at velocity changes of 5 and 7 km/h. The following dynamic response corridors were generated for the head, T1 (first thoracic vertebra) and head relative to T1: (1) accelerations in posterior-anterior direction, (2) horizontal and vertical displacements, (3) angular displacements for 6 females close to the 50th percentile in size. Additionally, the head-to-head restraint distance and contact time and neck injury criterion (NIC) were extracted from the data set. These data were compared to results from previously performed male volunteer tests, representing the 50th percentile male, in equivalent test conditions. T-tests were performed with the statistical significance level of .05 to quantify the significance of the parameter value differences for the males and females. At 7 km/h, the females showed 29 percent earlier head-to-head restraint contact time (p = .0072); 27 percent shorter horizontal rearward head displacement (p = .0017); 36 percent narrower head extension angle (p = .0281); and 52 percent lower NIC value (p = .0239) than the males in previous tests. This was mainly due to 35 percent shorter initial head-to-head restraint distance for the females (p = .0125). The peak head acceleration in the posterior-anterior direction was higher and occurred earlier for the females. The overall result indicated differences in the dynamic response for the female and male volunteers. The results could be used in developing and evaluating a mechanical and/or mathematical average-sized female dummy model for rear impact safety assessment. These models can be used as a tool in the design of protective systems and for further development and evaluation of injury criteria.

Repeatability study of replicate crash tests: A signal analysis approach.

PubMed

Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

2017-10-03

To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test

Biomechanics of Sports-Induced Axial-Compression Injuries of the Neck

PubMed Central

Ivancic, Paul C.

2012-01-01

Context Head-first sports-induced impacts cause cervical fractures and dislocations and spinal cord lesions. In previous biomechanical studies, researchers have vertically dropped human cadavers, head-neck specimens, or surrogate models in inverted postures. Objective To develop a cadaveric neck model to simulate horizontally aligned, head-first impacts with a straightened neck and to use the model to investigate biomechanical responses and failure mechanisms. Design Descriptive laboratory study. Setting Biomechanics research laboratory. Patients or Other Participants Five human cadaveric cervical spine specimens. Intervention(s) The model consisted of the neck specimen mounted horizontally to a torso-equivalent mass on a sled and carrying a surrogate head. Head-first impacts were simulated at 4.1 m/s into a padded, deformable barrier. Main Outcome Measure(s) Time-history responses were determined for head and neck loads, accelerations, and motions. Average occurrence times of the compression force peaks at the impact barrier, occipital condyles, and neck were compared. Results The first local compression force peaks at the impact barrier (3070.0 ± 168.0 N at 18.8 milliseconds), occipital condyles (2868.1 ± 732.4 N at 19.6 milliseconds), and neck (2884.6 ± 910.7 N at 25.0 milliseconds) occurred earlier than all global compression peaks, which reached 7531.6 N in the neck at 46.6 milliseconds (P < .001). Average peak head motions relative to the torso were 6.0 cm in compression, 2.4 cm in posterior shear, and 6.4° in flexion. Neck compression fractures included occipital condyle, atlas, odontoid, and subaxial comminuted burst and facet fractures. Conclusions Neck injuries due to excessive axial compression occurred within 20 milliseconds of impact and were caused by abrupt deceleration of the head and continued forward torso momentum before simultaneous rebound of the head and torso. Improved understanding of neck injury mechanisms during sports-induced impacts

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

Development and field performance of indy race car head impact padding.

PubMed

Melvin, J W; Bock, H; Anderson, K; Gideon, T

2001-11-01

The close-fitting cockpit of the modern Indy car single seat race car has the potential to provide a high level of head and neck impact protection in rear and side impacts. Crash investigation has shown that a wide variety of materials have been used as the padding for these cockpits and, as a result, produced varying outcomes in crashes. Additionally, these pads have not always been positioned for optimal performance. The purpose of this study was to investigate the head impact performance of a variety of energy-absorbing padding materials under impact conditions typical of Indy car rear impacts and to identify superior materials and methods of improving their performance as race car head pads. An extensive series of tests with the helmeted Hybrid III test dummy head and neck on an impact mini-sled was conducted to explore head padding concepts. Following this, a performance specification for a simplified impact test using a rigid headform that simulates the helmeted head was developed and recommendations for performance levels of head padding based on biomechanical data on helmeted head impacts were made. In 1997, during the time that the head pad research was being performed, the Indy Racing League introduced a new chassis specification for their cars. There were a number of rear- and side-impact crashes during that season that resulted in seven severe head injuries. Examples of the head padding in those cars were included in the experimental study. The results of the head pad research were used to specify new padding materials that met the new biomechanical criteria. The placement of the head pads was also changed for better location of the padding. These changes instituted in 1998 have reduced the number of head injuries in crashes similar to or more severe than those of 1997 and have resulted in only occasional moderate head injuries (concussions) in the 1998 and 1999 seasons.

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.

Occupant restraint in the rear seat: ATD responses to standard and pre-tensioning, force-limiting belt restraints.

PubMed

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

2008-10-01

Recent studies have shown that restrained occupants over the age of 50 in frontal crashes have a higher risk of injury in the rear seat than in the front, and have hypothesized that the incorporation of technology such as belt pre-tensioning and force limiting preferentially in the front seat is at least partially responsible for this trend. This study investigates the potential benefits and trade-offs of seat belt pretensioners and force-limiters in the rear seat using a series of frontal impact sled tests at two speeds (48 km/h and 29 km/h DeltaV) with a buck representing the interior of the reat seat occupant compartment of a contemporary mid-sized sedan. Four different dummies were tested: the Hybrid III six year old (in a booster seat, H3 6YO), the Hybrid III 5(th) percentile female (H3 AF05), the Hybrid III 50(th) percentile male (H3 AM50), and the THOR-NT. The restraints consisted of either a standard three point belt, or a 3-point belt with a retractor pretensioner and a progressive force-limiter (FL+PT). Each test condition was repeated in triplicate. The FL+PT restraints (compared to the standard restraints) resulted in a significant (p < or = 0.05) decrease in peak internal chest deflection for each of the Hybrid III dummies at both test speeds (48 km/h: 29% decrease for H3 6YO, 38% decrease for H3 AF05, 30% decrease for H3 AM50), and for the THOR-NT at a DeltaV of 29 km/h. At 48 km/h, the FL+PT restraint qualitatively decreased the average peak internal chest deflection of the THOR-NT, however this decrease was not statistically significant (p=0.06). Furthermore, the FL+PT system allowed little or no increase in forward head excursion, and improved whole-body kinematics for all dummies by restricting pelvic excursion and slightly increasing torso pitch. The results suggest that the FL+PT system studied here may provide injury-reducing benefit to rear seat occupants in moderate to high severity frontal crashes, although more study is needed to evaluate

Shipboard report for Hawaii GLORIA ground-truth cruise F11-88-HW, 25 Oct.-7 Nov., 1988

USGS Publications Warehouse

Clague, David A.; Holcomb, Robin T.; Torresan, Michael E.; Ross, Stephanie L.

1989-01-01

GLORIA side-scan imagery of the region north of Oahu was collected during two cruises in the spring of 1988. These cruises, F4-88-HW and F6-88-HW, discovered an extensive lava flow field on the Hawaiian Arch and extensive landslide deposits that moved down through the Hawaiian Moat and up onto the Hawaiian Arch. These landslide deposits were apparently derived from two separate submarine failures on the north side of Molokai and the northeast side of Oahu. The cruise reports for these cruises will be released as USGS Open-File Reports in 1989.This report summarizes the results of a subsequent cruise, F11-88-HW on the R/V Farnella, to sample some of the features discovered during the prior GLORIA surveys. Cruise F11-88-HW began in Honolulu on Oct. 25, 1988 and ended in Honolulu on Nov. 7, 1988. The major objectives of the cruise were to sample the giant lava field north of Oahu (Figure 1), to sample an apparently young flow between Oahu and Kauai (Figure 2) , to do some preliminary sampling of the deposits of the Nuuanu giant landslide northnortheast of Oahu, and to determine the thickness of sediment on flows in this lava field to compare to the acoustic backscatter variations observed in the GLORIA imagery of the flow field.These objectives were modified during the cruise due to rough seas which limited the deployment of the camera sled and to problems with the coring equipment which limited us to collecting 10 ft gravity cores. In particular, we did not complete any work aimed directly at the Nuuanu landslide deposits. The comparison of sediment thickness on the flows to observed acoustic backscatter on the GLORIA images was not completed because flows with intermediate backscatter were found to have thicker sediment than we could sample. The other objectives were achieved and lava samples of the flows and vents of the flow field were recovered from 23 locations. Gravity cores on top of the flows also determined the sediment thickness at 12 locations. The flow