WorldWideScience

Sample records for repetitive shock test

  1. A miniature high repetition rate shock tube.

    Science.gov (United States)

    Tranter, R S; Lynch, P T

    2013-09-01

    A miniature high repetition rate shock tube with excellent reproducibility has been constructed to facilitate high temperature, high pressure, gas phase experiments at facilities such as synchrotron light sources where space is limited and many experiments need to be averaged to obtain adequate signal levels. The shock tube is designed to generate reaction conditions of T > 600 K, P shock waves with predictable characteristics are created, repeatably. Two synchrotron-based experiments using this apparatus are also briefly described here, demonstrating the potential of the shock tube for research at synchrotron light sources.

  2. Fractionated Repetitive Extracorporeal Shock Wave Therapy: A New Standard in Shock Wave Therapy?

    Directory of Open Access Journals (Sweden)

    Tobias Kisch

    2015-01-01

    Full Text Available Background. ESWT has proven clinical benefit in dermatology and plastic surgery. It promotes wound healing and improves tissue regeneration, connective tissue disorders, and inflammatory skin diseases. However, a single treatment session or long intervals between sessions may reduce the therapeutic effect. The present study investigated the effects of fractionated repetitive treatment in skin microcirculation. Methods. 32 rats were randomly assigned to two groups and received either fractionated repetitive high-energy ESWT every ten minutes or placebo shock wave treatment, applied to the dorsal lower leg. Microcirculatory effects were continuously assessed by combined laser Doppler imaging and photospectrometry. Results. In experimental group, cutaneous tissue oxygen saturation was increased 1 minute after the first application and until the end of the measuring period at 80 minutes after the second treatment (P<0.05. The third ESWT application boosted the effect to its highest extent. Cutaneous capillary blood flow showed a significant increase after the second application which was sustained for 20 minutes after the third application (P<0.05. Placebo group showed no statistically significant differences. Conclusions. Fractionated repetitive extracorporeal shock wave therapy (frESWT boosts and prolongs the effects on cutaneous hemodynamics. The results indicate that frESWT may provide greater benefits in the treatment of distinct soft tissue disorders compared with single-session ESWT.

  3. Analyzing the effect of high repetition laser shock peening on dynamic corrosion rate of magnesium

    Science.gov (United States)

    Caralapatti, Vinodh Krishna; Narayanswamy, Sivakumar

    2017-08-01

    Magnesium as implant material is being investigated extensively due to its superior suitability. With corrosion rate being the major obstacle, this paper aims to determine the effects of high repetition laser shock peening (HRLSP) on the dynamic corrosion rate of magnesium. While there is lot of research on corrosion of magnesium, in this work, a specially designed test bench was used for characterization of dynamic corrosion to mimic the physiological conditions experienced by the implant inside human body. From the results, it can be inferred that corrosion rate of peened samples reduced by at least 6 times compared to unpeened sample and sample peened with 66% overlap 1 scans exhibited the least corrosion. The wettability of the samples was also determined as a measure to analyze the effects of HRLSP on biocompatibility. In addition, peening is seen to induce surface corrosion, which minimizes the risks of implant failure.

  4. 33 CFR 159.105 - Shock test.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Shock test. 159.105 Section 159... MARINE SANITATION DEVICES Design, Construction, and Testing § 159.105 Shock test. The device, with liquid... shocks that are ten times the force of gravity (10g) and have a duration of 20-25 milliseconds...

  5. 33 CFR 183.584 - Shock test.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Shock test. 183.584 Section 183... SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Tests § 183.584 Shock test. A fuel tank is tested by... surface of the tank. The duration of each vertical acceleration pulse is measured at the base of the...

  6. ROBUST REPETITIVE CONTROL FOR IMPROVING RATE SMOOTHNESS OF TEST TURNTABLE

    Institute of Scientific and Technical Information of China (English)

    LIUYu; ZENGMing; SUBao-ku

    2005-01-01

    A robust repetitive control scheme is used to improve the rate smoothness of a brushless DC motor (BLDCM) driven test turntable. The method synthesizes variable structure control (VSC) laws and repetitive control (RC) laws in a complementary manner. The VSC strategy can stabilize the system and suppress uncertainties, such as the aperiodic disturbance and noises, while RC strategy can eliminate the periodic rate fluctuation in a steady state. The convergence of the repetitive learning process is also guaranteed by VSC. A general nonlinear system model is discussed. The model can be considered as an extension of BLDCMs. The stability and asymptotic position tracking performance are validated by using Lyapunov functions. Simulation results show the effectiveness of the proposed approach for improving the rate smoothness.

  7. The Shock and Vibration Bulletin. Part 1. Invited Papers, Submarine Shock Testing, Shock Analysis, Shock Testing

    Science.gov (United States)

    1973-06-01

    P. White, Jr., Rochester Applied Science Associates, Inc., Rochester, New York MATHEMATICAL MODEL OF A TYPICAL FLOATING SHOCK PLATFORM SUBJECTED TO...our offer. standardization projects as well as in the This asrect of cuantitive railroad technology various technical societies. This multi...Analysis of a Gravity phenomena which my education had kept care- Dam," using gelatin models . The stimulation fully hidden from me until that time. It’s

  8. Effect of high repetition laser shock peening on biocompatibility and corrosion resistance of magnesium

    Science.gov (United States)

    Caralapatti, Vinodh Krishna; Narayanswamy, Sivakumar

    2017-02-01

    Magnesium, as a biomaterial has the potential to replace conventional implant materials owing to its numerous advantages. However, high corrosion rate is a major obstacle that has to be addressed for its implementation as implants. This study aims to evaluate the feasibility and effects of High Repetition Laser Shock Peening (HRLSP) on biocompatibility and corrosion resistance of Mg samples and as well as to analyze the effect of operational parameters such as peening with overlap on corrosion rate. From the results obtained using hydrogen evolution and mass loss methods, it was found that corrosion rates of both 0% overlap and 66% overlap peened samples reduced by more than 50% compared to that of unpeened sample and sample peened with 66% overlap exhibited least corrosion. The biocompatibility of peened Mg samples was also enhanced as there was neither rapid pH variation nor large hydrogen bubble formation around samples.

  9. Repetitive concussive traumatic brain injury interacts with post-injury foot shock stress to worsen social and depression-like behavior in mice.

    Directory of Open Access Journals (Sweden)

    Kristen C Klemenhagen

    Full Text Available The debilitating effects of repetitive concussive traumatic brain injury (rcTBI have been increasingly recognized in both military and civilian populations. rcTBI may result in significant neurological, cognitive, and affective sequelae, and is often followed by physical and/or psychological post-injury stressors that may exacerbate the effects of the injury and prolong the recovery period for injured patients. However, the consequences of post-injury stressors and their subsequent effects on social and emotional behavior in the context of rcTBI have been relatively little studied in animal models. Here, we use a mouse model of rcTBI with two closed-skull blunt impacts 24 hours apart and social and emotional behavior testing to examine the consequences of a stressor (foot shock fear conditioning following brain injury (rcTBI. rcTBI alone did not affect cued or contextual fear conditioning or extinction compared to uninjured sham animals. In the sucrose preference test, rcTBI animals had decreased preference for sucrose, an anhedonia-like behavior, regardless of whether they experienced foot shock stress or were non-shocked controls. However, rcTBI and post-injury foot shock stress had synergistic effects in tests of social recognition and depression-like behavior. In the social recognition test, animals with both injury and shock were more impaired than either non-shocked injured mice or shocked but uninjured mice. In the tail suspension test, injured mice had increased depression-like behavior compared with uninjured mice, and shock stress worsened the depression-like behavior only in the injured mice with no effect in the uninjured mice. These results provide a model of subtle emotional behavioral deficits after combined concussive brain injury and stress, and may provide a platform for testing treatment and prevention strategies for social behavior deficits and mood disorders that are tailored to patients with traumatic brain injury.

  10. Test section configuration for aerodynamic testing in shock tubes

    Science.gov (United States)

    Cook, W. J.; Presley, L. L.; Chapman, G. T.

    1980-01-01

    This paper presents results of a study of the test section configuration required to minimize or alleviate interference effects on model flow produced by the presence of test section walls in the aerodynamic testing of two dimensional transonic airfoils in a shock tube. Tests at a nominal Mach number of 0.85 and a chord Reynolds number of 2,000,000 were carried out by means of schlieren photography and pressure measurements for several symmetric airfoil profiles using shock tube test sections with unmodified straight walls, contoured walls, and slotted walls with adjacent chambers. Results were compared with corresponding results from conventional wind tunnel tests of the airfoils. Results for the straight wall tests show major airfoil flow distortions. Results from contoured wall tests and those performed using a slotted wall test section developed in this study exhibit essential agreement with wind tunnel results. The collective results show that test sections for aerodynamic testing can be designed for shock tubes that will alleviate wall interference effects.

  11. A shock tube with a high-repetition-rate time-of-flight mass spectrometer for investigations of complex reaction systems

    Science.gov (United States)

    Dürrstein, Steffen H.; Aghsaee, Mohammad; Jerig, Ludger; Fikri, Mustapha; Schulz, Christof

    2011-08-01

    A conventional membrane-type stainless steel shock tube has been coupled to a high-repetition-rate time-of-flight mass spectrometer (HRR-TOF-MS) to be used to study complex reaction systems such as the formation of pollutants in combustion processes or formation of nanoparticles from metal containing organic compounds. Opposed to other TOF-MS shock tubes, our instrument is equipped with a modular sampling unit that allows to sample with or without a skimmer. The skimmer unit can be mounted or removed in less than 10 min. Thus, it is possible to adjust the sampling procedure, namely, the mass flux into the ionization chamber of the HRR-TOF-MS, to the experimental situation imposed by species-specific ionization cross sections and vapor pressures. The whole sampling section was optimized with respect to a minimal distance between the nozzle tip inside the shock tube and the ion source inside the TOF-MS. The design of the apparatus is presented and the influence of the skimmer on the measured spectra is demonstrated by comparing data from both operation modes for conditions typical for chemical kinetics experiments. The well-studied thermal decomposition of acetylene has been used as a test system to validate the new setup against kinetics mechanisms reported in literature.

  12. A shock tube with a high-repetition-rate time-of-flight mass spectrometer for investigations of complex reaction systems.

    Science.gov (United States)

    Dürrstein, Steffen H; Aghsaee, Mohammad; Jerig, Ludger; Fikri, Mustapha; Schulz, Christof

    2011-08-01

    A conventional membrane-type stainless steel shock tube has been coupled to a high-repetition-rate time-of-flight mass spectrometer (HRR-TOF-MS) to be used to study complex reaction systems such as the formation of pollutants in combustion processes or formation of nanoparticles from metal containing organic compounds. Opposed to other TOF-MS shock tubes, our instrument is equipped with a modular sampling unit that allows to sample with or without a skimmer. The skimmer unit can be mounted or removed in less than 10 min. Thus, it is possible to adjust the sampling procedure, namely, the mass flux into the ionization chamber of the HRR-TOF-MS, to the experimental situation imposed by species-specific ionization cross sections and vapor pressures. The whole sampling section was optimized with respect to a minimal distance between the nozzle tip inside the shock tube and the ion source inside the TOF-MS. The design of the apparatus is presented and the influence of the skimmer on the measured spectra is demonstrated by comparing data from both operation modes for conditions typical for chemical kinetics experiments. The well-studied thermal decomposition of acetylene has been used as a test system to validate the new setup against kinetics mechanisms reported in literature.

  13. Development of Thermal Shock Test Facility

    Science.gov (United States)

    Lehmann, B.; Varewijck, G.; Dufour, J.-F.

    2012-07-01

    Thermal shock testing is performed to qualify materials and processes for use in space in accordance to ECSS- Q-70-04A. The Fast Thermal Vacuum facility (FTV) has been specially designed to allow testing from -100oC up to 550oC. This large temperature test range is achieved by having two separate temperature controlled compartments. The specimen is placed on a trolley, which moves from one compartment to the other. The challenge in development of the facility was the relatively large size of the compartments (600 mm x 600 mm x 400 mm) and the required vacuum level of p~1E-05 mbar. The FTV was successfully commissioned in September 2010. The presentation summarises the results of the commissioning, facility performance, test data and lessons learned.

  14. Repetitive Cyclic Potentiodynamic Polarization Scan Results for Reduced Sample Volume Testing

    Energy Technology Data Exchange (ETDEWEB)

    LaMothe, Margaret E. [Washington River Protection Solutions, Richland, WA (United States)

    2016-03-15

    This report is the compilation of data gathered after repetitively testing simulated tank waste and a radioactive tank waste sample using a cyclic potentiodynamic polarization (CPP) test method to determine corrosion resistance of metal samples. Electrochemistry testing of radioactive tank samples is often used to assess the corrosion susceptibility and material integrity of waste tank steel. Repetitive testing of radiological tank waste is occasionally requested at 222-S Laboratory due to the limited volume of radiological tank sample received for testing.

  15. Sequential shock induced switch tests for Eglin Air Force Base

    Energy Technology Data Exchange (ETDEWEB)

    Cech, R.D.

    1994-08-11

    Tests were performed at EG&G Mound Applied Technologies to investigate the effect of using the tangential shock wave from detonating Extex explosive to cause shock conduction of a Kapton dielectric. Two voltages (600 and 4000) were switched from a 600 pF capacitor. Timing between four shock switches and four pin switches was found and compared during a single detonation event. Electrical conduction was observed between shock switches and the current paths were found.

  16. 14 CFR 23.723 - Shock absorption tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shock absorption tests. 23.723 Section 23... Landing Gear § 23.723 Shock absorption tests. (a) It must be shown that the limit load factors selected... exceeded. This must be shown by energy absorption tests except that analysis based on tests conducted on...

  17. Shock priming enhances the efficacy of SSRIs in the foot shock-induced ultrasonic vocalization test.

    Science.gov (United States)

    Kassai, Ferenc; Gyertyán, István

    2012-01-10

    Data on the effect of acutely administered serotonin reuptake inhibitors (SSRIs) in animal anxiety models have been inconsistent. In some of the models these compounds showed anxiolytic properties, while in others they were ineffective or even anxiogenic. In the foot shock-induced ultrasonic vocalization (USV) test in the adult rat, SSRIs were reported to be effective, however, they were only tested with protocols using multiple shocking design. In the present study, anxiolytic effects of various SSRI compounds (sertraline, fluoxetine, paroxetine, escitalopram) were tested in three distinct USV test protocols in comparison with alprazolam and 8-OH-DPAT. In the single shocking protocol, animals were exposed to one shocking session after the drug treatment. In the multiple shocking protocol, rats went through a foot shock priming session before each drug test. On priming days animals received foot shocks without drug treatment. On the test day (the day after), rats received drug treatment and then were shocked again. In the context conditioning protocol animals were exposed to foot shocks on two consecutive days before the drug test. On the third, test day, after drug treatment animals were replaced to the shocking chamber, but this time shocks were not delivered. SSRIs were ineffective using the single shocking protocol. In the context conditioned protocol, all SSRIs showed linear dose-response relationship with ED50 values of 8.5, 2.2, 0.77 and 0.93 mg/kg i.p. for fluoxetine, sertraline, paroxetine and escitalopram, respectively. Using the multiple shocking protocol, SSRIs were only partially effective with maximum inhibitions ranging between 44% and 62%. In contrast to SSRIs, the benzodiazepine anxiolytics, alprazolam showed anxiolytic activity with linear dose-response relationship in all of the test protocols, with ED50 values varying from 1.3 to 4.0 mg/kg i.p. The serotonin 5HT1A receptor antagonist 8-OH-DPAT also showed linear dose-response relationship in all

  18. 14 CFR 29.723 - Shock absorption tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shock absorption tests. 29.723 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the...

  19. 14 CFR 27.723 - Shock absorption tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shock absorption tests. 27.723 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.723 Shock absorption tests. The landing inertia load factor and the reserve energy absorption capacity of the...

  20. 14 CFR 25.723 - Shock absorption tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shock absorption tests. 25.723 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Landing Gear § 25.723 Shock absorption tests. (a) The analytical representation of the landing gear dynamic characteristics that is...

  1. Design of water shock tube for testing shell materials

    OpenAIRE

    Ji, Hongjuan; Mustafa, Mohamad; Khawaja, Hassan Abbas; Ewan, Bruce C.; Moatamedi, Mojtaba

    2014-01-01

    This paper presents design considerations for a shock tube experimental rig used to investigate the dynamic failure mechanisms of shell geometries subjected to water shock impact loading. In such setup, it is desirable that the drive pressure used within the tube can provide a wide range of impulsive loads on the test structures and some flexibility can be achieved on the applied pulse durations. With this aim a review of various existing shock tube experimental setup is presented and choi...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, Troy [Honeywell Federal Manufacturing and Technologies, Kansas City, MO (United States); Hower, Brent [Honeywell Federal Manufacturing and Technologies, Kansas City, MO (United States); Seaholm, Aaron [Honeywell Federal Manufacturing and Technologies, Kansas City, MO (United States)

    2007-11-08

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

  3. Computer modeling of test particle acceleration at oblique shocks

    Science.gov (United States)

    Decker, Robert B.

    1988-01-01

    The present evaluation of the basic techniques and illustrative results of charged particle-modeling numerical codes suitable for particle acceleration at oblique, fast-mode collisionless shocks emphasizes the treatment of ions as test particles, calculating particle dynamics through numerical integration along exact phase-space orbits. Attention is given to the acceleration of particles at planar, infinitessimally thin shocks, as well as to plasma simulations in which low-energy ions are injected and accelerated at quasi-perpendicular shocks with internal structure.

  4. Sentence Repetition Test for Measurement of Grammatical Development in Farsi Speaking Children

    Directory of Open Access Journals (Sweden)

    Mohammad Kamali

    2011-06-01

    Full Text Available Background and Aim: valid identification, prevention, and treatment of language disorders are a high priority for the speech and language professionals. One method for studying language development is sentence repetition that is faster to implement and analysis than other procedures. The aim of this project was constructing sentence repetition test as a quick measure of grammatical potency in 2.5 to 4 year old children.Methods: Sentences appropriate for 2.5 to 4 year old children were selected during several stages by speech and language pathologist and linguists. The validity of sentences was assessed by professional masters in this theme. Subsequently, 41 sentences including those with 80% high validity were selected as the test sentences. Appropriate pictures were also provided with sentences. The test was administrated to 72 children in 3 groups (2.5-3, 3-3.5, and 3.5-4 year olds, gender matched. The reliability was administered with a test-retest design across a 2 weeks interval.Results: Content validity Index for this test was 80%. "Test-retest reliability” was used for reliability of this test. The Interclass correlation coefficient for this test was 0.95 and standard error measurement was 7.45. The average of scores for sentence repetition, between groups was significant (p<0.001, p<0.001, p= 0.014.Conclusion: This sentence repetition test has the appropriate validity and reliability as well as the capability of proper and quick assessment (screening of grammatical development in 2.5 to 4 year old Persian speaking children.

  5. A New Combination Facility for Testing Refraction, Diffraction and Interaction of Shock Waves

    Institute of Scientific and Technical Information of China (English)

    杨基明; 韩肇元; 尹协振

    1994-01-01

    In this paper, a new facility is introduced, which is the combination of a shock tunnel and a shock tube. Experiments on refraction of a moving shock at a slip-surface, diffraction of a moving shock around a corner under the condition of a uniform flow ahead of the shock, and interaction of a moving shock with a bow shock attached to a testing model were conducted in the combinated facility and some new phenomena were observed.

  6. Building an Assessment Use Argument for sign language: the BSL Nonsense Sign Repetition Test

    OpenAIRE

    Mann, W.; Marshall, C. R.

    2010-01-01

    In this article, we adapt a concept designed to structure language testing more effectively, the Assessment Use Argument (AUA), as a framework for the development and/or use of sign language assessments for deaf children who are taught in a sign bilingual education setting. By drawing on data from a recent investigation of deaf children's nonsense sign repetition skills in British Sign Language, we demonstrate the steps of implementing the AUA in practical test design, development and use. Th...

  7. INCAS QUICK THERMAL TEST SHOCK INSTALLATION - QTS1

    Directory of Open Access Journals (Sweden)

    Constantin VILCU

    2009-12-01

    Full Text Available From the assembly of the wear factors which act on the “hot parts” of the turbo engines,respectively on the protective coatings, the thermal shock acts the most perturbing.The behavior of the materials at thermal shock is evaluated at present on unique installations,constructive and methodical different, in the specialized laboratories of the materialsmanufacturer, protective coatings included as well as of those specialized in testing.The thermal test shock installation conceived by INCAS and achieved in collaboration with INCDTCOMOTI for testing of the materials at thermal shock, especially those from the aerospatialdomain, represents a versatile construction, in progress in comparison with those known.The QTS1 - quick thermal test shock installation assures with reproducible results the materialevaluation in the heating and cooling speed conditions up to 100°C/s at heating and 60ºC/s atcooling, situations which correspond to the extreme functional conditions of the turbo engines,space shuttle, cogenerative systems, etc.

  8. The selection and evaluation of shock test instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Butler, R. I. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Dove, R. C. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    1966-02-11

    If shock test results are to be of any value the data which will be appropriate must be decided upon; the test must be instrumented so that signals related to the desired data will be made available, and these signals must be interpreted.

  9. Laboratory Test Requirements for Marine Shock Isolation Seats

    Science.gov (United States)

    2015-05-01

    Program Executive Office Ships, Support Ships, Boats, and Craft Program Office (PMS 325G). ACKNOWLEDGEMENTS The authors would like to thank Mr...laboratory before installation in a high-speed planing craft . It includes testing procedures, instrumentation system guidance, data processing requirements...or techniques are developed. . 15. SUBJECT TERMS Shock isolation seat laboratory test high-speed craft 16. SECURITY

  10. Shock Radiation Tests for Saturn and Uranus Entry Probes

    Science.gov (United States)

    Cruden, Brett A.; Bogdanoff, David W.

    2014-01-01

    This paper describes a test series in the Electric Arc Shock Tube at NASA Ames Research Center with the objective of quantifying shock-layer radiative heating magnitudes for future probe entries into Saturn and Uranus atmospheres. Normal shock waves are measured in Hydrogen/Helium mixtures (89:11 by mole) at freestream pressures between 13-66 Pa (0.1-0.5 Torr) and velocities from 20-30 km/s. No shock layer radiation is detected below 25 km/s, a finding consistent with predictions for Uranus entries. Between 25-30 km/s, radiance is quantified from the Vacuum Ultraviolet through Near Infrared, with focus on the Lyman-alpha and Balmer series lines of Hydrogen. Shock profiles are analyzed for electron number density and electronic state distribution. The shocks do not equilibrate over several cm, and distributions are demonstrated to be non-Boltzmann. Radiation data are compared to simulations of Decadal survey entries for Saturn and shown to be significantly lower than predicted with the Boltzmann radiation model.

  11. Shock margin testing of a one-axis MEMS accelerometer.

    Energy Technology Data Exchange (ETDEWEB)

    Parson, Ted Blair; Tanner, Danelle Mary; Buchheit, Thomas Edward

    2008-07-01

    Shock testing was performed on a selected commercial-off-the-shelf - MicroElectroMechanical System (COTS-MEMS) accelerometer to determine the margin between the published absolute maximum rating for shock and the 'measured' level where failures are observed. The purpose of this testing is to provide baseline data for isolating failure mechanisms under shock and environmental loading in a representative device used or under consideration for use within systems and assemblies of the DOD/DOE weapons complex. The specific device chosen for this study was the AD22280 model of the ADXL78 MEMS Accelerometer manufactured by Analog Devices Inc. This study focuses only on the shock loading response of the device and provides the necessary data for adding influence of environmental exposure to the reliability of this class of devices. The published absolute maximum rating for acceleration in any axis was 4000 G for this device powered or unpowered. Results from this study showed first failures at 8000 G indicating a margin of error of two. Higher shock level testing indicated that an in-plane, but off-axis acceleration was more damaging than one in the sense direction.

  12. Reliability of the one-repetition-maximum power clean test in adolescent athletes.

    Science.gov (United States)

    Faigenbaum, Avery D; McFarland, James E; Herman, Robert E; Naclerio, Fernando; Ratamess, Nicholas A; Kang, Jie; Myer, Gregory D

    2012-02-01

    Although the power clean test is routinely used to assess strength and power performance in adult athletes, the reliability of this measure in younger populations has not been examined. Therefore, the purpose of this study was to determine the reliability of the 1-repetition maximum (1RM) power clean in adolescent athletes. Thirty-six male athletes (age 15.9 ± 1.1 years, body mass 79.1 ± 20.3 kg, height 175.1 ±7.4 cm) who had >1 year of training experience in weightlifting exercises performed a 1RM power clean on 2 nonconsecutive days in the afternoon following standardized procedures. All test procedures were supervised by a senior level weightlifting coach and consisted of a systematic progression in test load until the maximum resistance that could be lifted for 1 repetition using proper exercise technique was determined. Data were analyzed using an intraclass correlation coefficient (ICC[2,k]), Pearson correlation coefficient (r), repeated measures analysis of variance, Bland-Altman plot, and typical error analyses. Analysis of the data revealed that the test measures were highly reliable demonstrating a test-retest ICC of 0.98 (95% confidence interval = 0.96-0.99). Testing also demonstrated a strong relationship between 1RM measures in trials 1 and 2 (r = 0.98, p adolescent athletes when standardized testing procedures are followed and qualified instruction is present.

  13. RELIABILITY OF THE ONE REPETITION-MAXIMUM POWER CLEAN TEST IN ADOLESCENT ATHLETES

    Science.gov (United States)

    Faigenbaum, Avery D.; McFarland, James E.; Herman, Robert; Naclerio, Fernando; Ratamess, Nicholas A.; Kang, Jie; Myer, Gregory D.

    2013-01-01

    Although the power clean test is routinely used to assess strength and power performance in adult athletes, the reliability of this measure in younger populations has not been examined. Therefore, the purpose of this study was to determine the reliability of the one repetition maximum (1 RM) power clean in adolescent athletes. Thirty-six male athletes (age 15.9 ± 1.1 yrs, body mass 79.1 ± 20.3 kg, height 175.1 ±7.4 cm) who had more than 1 year of training experience with weightlifting exercises performed a 1 RM power clean on two nonconsecutive days in the afternoon following standardized procedures. All test procedures were supervised by a senior level weightlifting coach and consisted of a systematic progression in test load until the maximum resistance that could be lifted for one repetition using proper exercise technique was determined. Data were analyzed using an intraclass correlation coefficient (ICC [2,k]), Pearson correlation coefficient (r), repeated measures ANOVA, Bland-Altman plot, and typical error analyses. Analysis of the data revealed that the test measures were highly reliable demonstrating a test-retest ICC of 0.98 (95% CI = 0.96–0.99). Testing also demonstrated a strong relationship between 1 RM measures on trial 1 and trial 2 (r=0.98, padolescent athletes when standardized testing procedures are followed and qualified instruction is present. PMID:22233786

  14. Reliability and validity of the five-repetition sit-to-stand test for children with cerebral palsy.

    Science.gov (United States)

    Wang, Tze-Hsuan; Liao, Hua-Fang; Peng, Yi-Chun

    2012-07-01

    OBJECTIVE To investigate the psychometric properties of the five-repetition sit-to-stand test, a functional strength test, in children with spastic diplegia. Methodology study. Hospital, laboratory or home. In total, 108 children with spastic diplegia and 62 with typical development aged from five to 12 years were tested. For test-retest reliability, 22 children with spastic diplegia were tested twice within one week. Not applicable. The five-repetition sit-to-stand test measures time needed to complete five consecutive sit-to-stand cycles as quickly as possible. The higher the rate of five-repetition sit-to-stand (repetitions per second), the more strength a person has. The intraclass correlation coefficients of intra-session reliability and test-retest reliability were 0.95 and 0.99 respectively. The minimal detectable difference was 0.06 rep/sec. The convergent validity of the five-repetition sit-to-stand test was supported by significant correlation with one-repetition maximum of the loaded sit-to-stand test, isometric muscle strength, scores of Gross Motor Function Measure, and gait function (r or rho = 0.40-0.78). For known group validity, children with typical development and children classified as Gross Motor Function Classification System level I performed higher rates of five-repetition sit-to-stand than children classified as level II, and children classified as level II performed higher rates than level III. The five-repetition sit-to-stand test was a reliable and valid test to measure functional muscle strength in children with spastic diplegia in clinics.

  15. Simulation and Analysis of Converging Shock Wave Test Problems

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Scott D. [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory

    2012-06-21

    Results and analysis pertaining to the simulation of the Guderley converging shock wave test problem (and associated code verification hydrodynamics test problems involving converging shock waves) in the LANL ASC radiation-hydrodynamics code xRAGE are presented. One-dimensional (1D) spherical and two-dimensional (2D) axi-symmetric geometric setups are utilized and evaluated in this study, as is an instantiation of the xRAGE adaptive mesh refinement capability. For the 2D simulations, a 'Surrogate Guderley' test problem is developed and used to obviate subtleties inherent to the true Guderley solution's initialization on a square grid, while still maintaining a high degree of fidelity to the original problem, and minimally straining the general credibility of associated analysis and conclusions.

  16. Numerical Modeling of Dual-Pulse Shock Test Machine for Simulating Underwater Explosion Shock Loads on Warship Equipments

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-yi; WANG Gong-xian; WANG Yu

    2009-01-01

    In order to qualify shock resistance performance of shipboard equipments and simulate real underwater explosion environment, a novel dual-puise shock test machine is proposed. The new machine will increase testing capability and meet special shock testing requirement. Two key parts of the machine, the velocity generator and the shock pulse regulator, play an important role in producing the positive acceleration pulse and the succeeding negative acceleration pulse, respectively. The generated dual-pulse shock for test articles is in conformity with an anti-shock test specification. Based on the impact theory, a nonlinear dynamic model of the hydraulically-actuated test machine is established with thorough analysis on its mechanism that involves conversion of gas potential energy and dissipation of kinetic energy. Simulation results have demonstrated that the proposed machine is able to produce a double-pulse acceleration shock in the time domain or a desired shock response spectrum in the frequency domain, which sets up a base for the construction of the machine.

  17. The Shock and Vibration Bulletin. Part 3. Shock Testing, Shock Analysis

    Science.gov (United States)

    1974-08-01

    Tnrow tar,;et Int6 at.,ttl’Dc,-iy tes;t An 1r~pact tezt teclinftjup tCmlyh-~ 2.ofv taret.t t*. norttd re p41rewI impact envlr~r:.7.cnt haz tieen of...hen Iqs ( ) - 2 a d (3) are zul -ti- o *q. (’ i!ltemrat.d ,ver S L:. •h’ l,:’th o " t , r ’’: ., the l, th af the , . , ti-, o. imn- U or a %-_ r.J

  18. A study of test section configuration for shock tube testing of transonic airfoils

    Science.gov (United States)

    Cook, W. J.

    1978-01-01

    Two methods are investigated for alleviating wall interference effects in a shock tube test section intended for testing two-dimensional transonic airfoils. The first method involves contouring the test section walls to match approximate streamlines in the flow. Contours are matched to each airfoil tested to produce results close to those obtained in a conventional wind tunnel. Data from a previous study and the present study for two different airfoils demonstrate that useful results are obtained in a shock tube using a test section with contoured walls. The second method involves use of a fixed-geometry slotted-wall test section to provide automatic flow compensation for various airfoils. The slotted-wall test section developed exhibited the desired performance characteristics in the approximate Mach number range 0.82 to 0.89, as evidenced by good agreement obtained between shock tube and wind tunnel results for several airfoil flows.

  19. Effect of power density and pulse repetition on laser shock peening of Ti-6Al-4V

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.R.; Shepard, M.J.; Prevey, P.S. III; Clauer, A.H.

    2000-02-01

    Laser shock peening (LSP) was applied to Ti-6Al-4V (wt.%) simulated airfoil specimens using a Nd:Glass laser. Laser shock peening processing parameters examined in the present study included power density (5.5, 7, and 9 GW/cm{sup 2}) and number of laser pulses per spot (one and three pulses/spot). The LSP's Ti-6Al-4V samples were examined using x-ray diffraction techniques to determine the residual stress distribution and percent cold work as a function of depth. It was found that the residual stress state and percent of cold work were relatively independent of LSP power density. However, the number of laser pulses per spot had a significant effect on both residual stress and percent of cold work for a given power density level. In addition, there was a strong correlation between the magnitude of residual compressive stresses generated and the percent cold work measured.

  20. Comparison of Shock Response Spectrum for Different Gun Tests

    Directory of Open Access Journals (Sweden)

    J.A. Cordes

    2013-01-01

    Full Text Available The Soft Catch Gun at Picatinny Arsenal is regularly used for component testing. Most shots contain accelerometers which record accelerations as a function of time. Statistics of accelerometer data indicate that the muzzle exit accelerations are, on average, higher than tactical firings. For that reason, Soft Catch Gun tests with unusually high accelerations may not be scored for Lot Acceptance Tests (LAT by some customers. The 95/50 Normal Tolerance Limit (NTL is proposed as a means of determining which test results should be scored. This paper presents comparisons of Shock Response Spectra (SRS used for the 95/50 scoring criteria. The paper also provides a Discussion Section outlining some concerns with scoring LAT results based on test results outside of the proposed 95/50 criteria.

  1. Reference values of nonword repetition test for Brazilian Portuguese-speaking children

    Directory of Open Access Journals (Sweden)

    Simone Rocha de Vasconcellos Hage

    2009-01-01

    Full Text Available Evaluation of the phonological working memory (PWM through repetition of nonwords can provide important information on the linguistic abilities of children, thus differentiating those with and without communication disorders. OBJECTIVE: The aim of this study was to obtain reference values in the Nonword Repetition Test (NWRT in order to investigate the performance of children without language disorders concerning this type of memory. Material and METHODS: The study was conducted on 480 normal children of both genders aged 4 years to 8 years and 11 months, attending preschool and elementary school. The NWRT consisted of repeating 20 (children up to 4 years or 40 (for children aged 5 years or more invented words with 2 to 5 syllables. The results were subjected to descriptive statistical analysis. Comparison between ages and between the number of syllables in nonwords was performed by the Tukey's multiple-comparison test and one-way analysis of variance, at a significance value of p<0.05. RESULTS: There was statistically significant difference (p<0.05 in performance between children of different age groups, except between 7- and 8-year-olds. The analysis also showed statistically significant difference (p<0.05 in the number of syllables between the different age groups. CONCLUSIONS: The reference values obtained indicated an improvement in performance with the increase of age of children, indicating an improvement in the storage of verbal material in the PWM. The performance was worsened with the increase in the number of syllables in words, demonstrating that the greater the number of syllables, the greater is the difficulty in storing verbal material.

  2. ANALYSIS AND SIMULATION ON THE MECHANISM OF A NOVEL DUAL-WAVE SHOCK TEST MACHINE

    Institute of Scientific and Technical Information of China (English)

    WANG Gongxian; ZHANG Zhiyi; CHU Deying; SHEN Rongying

    2008-01-01

    For qualifying the anti-shock performance of shipboard equipments and simulating actual underwater explosion environments, a novel dual-wave shock test machine is proposed to increase testing capability of shock test machines as well as to meet certain shock testing specification. The machine can generate a double-pulse acceleration shock for test articles according to specification defined in BV043/85. On the basis of the impact theory, a nonlinear dynamic model of the hydraulically-actuated test machine is established with thorough analysis on its mechanism which involves conversion of gas potential energy and dissipation of kinetic energy. Simulation results have demonstrated that the machine can produce a double-pulse acceleration shock in the time domain or a desired shock response spectrum in the frequency domain, which sets a theoretical base for the construction of the proposed machine.

  3. USED FUEL RAIL SHOCK AND VIBRATION TESTING OPTIONS ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Steven B.; Best, Ralph E.; Klymyshyn, Nicholas A.; Jensen, Philip J.; Maheras, Steven J.

    2014-09-29

    The objective of the rail shock and vibration tests is to complete the framework needed to quantify loads of fuel assembly components that are necessary to guide materials research and establish a technical basis for review organizations such as the U.S. Nuclear Regulatory Commission (NRC). A significant body of experimental and numerical modeling data exists to quantify loads and failure limits applicable to normal conditions of transport (NCT) rail transport, but the data are based on assumptions that can only be verified through experimental testing. The test options presented in this report represent possible paths for acquiring the data that are needed to confirm the assumptions of previous work, validate modeling methods that will be needed for evaluating transported fuel on a case-by-case basis, and inform material test campaigns on the anticipated range of fuel loading. The ultimate goal of this testing is to close all of the existing knowledge gaps related to the loading of used fuel under NCT conditions and inform the experiments and analysis program on specific endpoints for their research. The options include tests that would use an actual railcar, surrogate assemblies, and real or simulated rail transportation casks. The railcar carrying the cradle, cask, and surrogate fuel assembly payload would be moved in a train operating over rail track modified or selected to impart shock and vibration forces that occur during normal rail transportation. Computer modeling would be used to help design surrogates that may be needed for a rail cask, a cask’s internal basket, and a transport cradle. The objective of the design of surrogate components would be to provide a test platform that effectively simulates responses to rail shock and vibration loads that would be exhibited by state-of-the-art rail cask, basket, and/or cradle structures. The computer models would also be used to help determine the placement of instrumentation (accelerometers and strain gauges

  4. Used fuel rail shock and vibration testing options analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Best, Ralph E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Klymyshyn, Nicholas A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maheras, Steven J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-25

    The objective of the rail shock and vibration tests is to complete the framework needed to quantify loads of fuel assembly components that are necessary to guide materials research and establish a technical basis for review organizations such as the U.S. Nuclear Regulatory Commission (NRC). A significant body of experimental and numerical modeling data exists to quantify loads and failure limits applicable to normal conditions of transport (NCT) rail transport, but the data are based on assumptions that can only be verified through experimental testing. The test options presented in this report represent possible paths for acquiring the data that are needed to confirm the assumptions of previous work, validate modeling methods that will be needed for evaluating transported fuel on a case-by-case basis, and inform material test campaigns on the anticipated range of fuel loading. The ultimate goal of this testing is to close all of the existing knowledge gaps related to the loading of used fuel under NCT conditions and inform the experiments and analysis program on specific endpoints for their research. The options include tests that would use an actual railcar, surrogate assemblies, and real or simulated rail transportation casks. The railcar carrying the cradle, cask, and surrogate fuel assembly payload would be moved in a train operating over rail track modified or selected to impart shock and vibration forces that occur during normal rail transportation. Computer modeling would be used to help design surrogates that may be needed for a rail cask, a cask’s internal basket, and a transport cradle. The objective of the design of surrogate components would be to provide a test platform that effectively simulates responses to rail shock and vibration loads that would be exhibited by state-of-the-art rail cask, basket, and/or cradle structures. The computer models would also be used to help determine the placement of instrumentation (accelerometers and strain gauges

  5. Shock

    Science.gov (United States)

    Shock can be caused by any condition that reduces blood flow, including: Heart problems (such as heart attack or heart failure ) Low blood volume (as with heavy bleeding or dehydration ) Changes in blood vessels (as with infection ...

  6. Optimizing human semen cryopreservation by reducing test vial volume and repetitive test vial sampling

    DEFF Research Database (Denmark)

    Jensen, Christian F S; Ohl, Dana A; Parker, Walter R

    2015-01-01

    OBJECTIVE: To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (-88°C to -93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen. DESIGN: Prospec......OBJECTIVE: To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (-88°C to -93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen. DESIGN...

  7. RELIABILITY OF THE ONE-REPETITION MAXIMUM TEST BASED ON MUSCLE GROUP AND GENDER

    Directory of Open Access Journals (Sweden)

    Dong-il Seo

    2012-06-01

    Full Text Available The purpose of the present study was to examine the influence of muscle group location and gender on the reliability of assessing the one-repetition maximum (1RM test. Thirty healthy males (n = 15 and females (n = 15 who experienced at least 3 months of continuous resistance training during the last 2 years aged 18-35 years volunteered to participate in the study. The 1RM for the biceps curl, lat pull down, bench press, leg curl, hip flexion, triceps extension, shoulder press, low row, leg extension, hip extension, leg press and squat were measured twice by a trained professional using a standard published protocol. Biceps curl, lat pull down, bench press, leg curl, hip flexion, and squat 1RM's were measured on the first visit, then 48 hours later, subjects returned for their second visit. During their second visit, 1RM of triceps extension, shoulder press, low row, leg extension, hip extension, and leg press were measured. One week from the second visit, participants completed the 1 RM testing as previously done during the first and second visits. The third and fourth visits were separated by 48 hours as well. All four visits to the laboratory were at the same time of day. A high intraclass correlation coefficient (ICC > 0.91 was found for all exercises, independent of gender and muscle group size or location, however there was a significant interaction for muscle group location (upper body vs. lower body in females (p < 0.027. In conclusion, a standardized 1RM testing protocol with a short warm-up and familiarization period is a reliable measurement to assess muscle strength changes regardless of muscle group location or gender

  8. Correlation between the 8-repetition maximum test and isokinetic dynamometry in the measurement of muscle strength of the knee extensors: A concurrent validity study.

    Science.gov (United States)

    Taylor, J David; Fletcher, James P

    2013-05-01

    The 8-repetition maximum test has the potential to be a feasible, cost-effective method of measuring muscle strength for clinicians. The purpose of this study was to investigate the concurrent validity of the 8-repetition maximum test in the measurement of muscle strength by comparing the 8-repetition maximum test to the gold standard of isokinetic dynamometry. Thirty participants (15 males and 15 females, mean age = 23.2 years [standard deviation = 1.0]) underwent 8-repetition maximum testing and isokinetic dynamometry testing of the knee extensors (at 60, 120, and 240 degrees per second) on two separate sessions with 2-3 days between each mode of testing. Linear regression was used to assess the validity by comparing the findings between 8-repetition maximum testing and isokinetic dynamometry testing. Significant correlations were found between the 8-repetition maximum and isokinetic dynamometry peak torque at each testing velocity (r  =  0.71-0.85). The highest correlations were between the 8-repetition maximum and isokinetic dynamometry peak torques at 60 (r  =  0.85) and 120 (r  =  0.85) degrees per second. The findings of this study provide supportive evidence for the use of 8-repetition maximum testing as a valid, alternative method for measuring muscle strength.

  9. Testing the Asymmetry of Shocks with Euro Area

    Directory of Open Access Journals (Sweden)

    Marius-Corneliu MARINAŞ

    2012-01-01

    Full Text Available The objective of this study is to identify the demand and supply shocks affecting 13 EU member states and to estimate their degree of correlation with the Euro area shocks. This research ensures identifying the asymmetry of shocks degree with the monetary union, depending on which it’s judging the desirability of adopting a single currency. The analysis is also useful for the economies outside the Euro area, because they are strongly commercial and financial integrated especially with the core economies from union. Applying the Blanchard and Quah methodology to estimate the shocks in the period from 1998:1- 2010:3, I have found a weak and negative correlation between demand shocks and a medium to high correlation of the supply shocks. The results obtained suggest the presence of a structural convergence process with the Euro area, in the context of domestic macroeconomic policies rather different, both inside and outside the monetary union.

  10. Test Method for Determination of Thermal Shock resistance(Air Quenching)

    Institute of Scientific and Technical Information of China (English)

    LIYong-gang; ZHANGYong-fang; 等

    1995-01-01

    On the basis of the theory of thermal shock resistance in the science of materials and the test method of air quenching which is generally rec-ognized internationally,especially in Europe,the present test methods for determination of thermal shock resistance in China have been analysed,Experiment study on thermal shock resis-tance of silica and basic refractory products has been conducted,and a new test method of thermal shock resistance-air quenching method has been put forward.

  11. Evaluation of fracture models through pressurized-thermal-shock testing

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, C.E.; Bryan, R.H.; Bass, B.R.; Nanstad, R.K.

    1988-01-01

    Two multiple-transient pressurized-thermal-shock experiments (PTSEs) have been conducted under the NRC-sponsored Heavy-Section Steel Technology (HSST) program. The first test (PTSE-1) employed an SA-508 class 2 steel with high Charpy upper-shelf energy level and a relatively high brittle-to-ductile transition temperature. The second test (PTSE-2) used a 2 1/4 Cr-1 Mo steel (SA-387 grade 22) that had been given a special heat treatment to yield a low Charpy upper-shelf energy level and attendant low tearing resistance. Each experiment included two combined thermal and pressure transients that give rise to propagation and arrest of an initial long flaw that extended about 10% through the thick wall of the test cylinder. Both materials exhibited the ability to inhibit crack propagation by warm prestressing, high initiation toughness values and high crack-arrest toughness values. Cleavage initiation and arrest are modeled well by available fracture theories. However, calculations of ductile tearing based on resistance curves did not consistently predict the observed tearing.

  12. Is it possible to change of the duration of consolidation period in the distraction osteogenesis with the repetition of extracorporeal shock waves?

    Science.gov (United States)

    Bereket, Cihan; Sener, Ismail; Ozkan, Nilufer; Senel, Erman; Polat, Ahmet-Veysel

    2017-01-01

    Background In this study we examined the effects of two different repeated Extracorporeal Shock Waves (ESW) on the consolidation period of the distraction osteogenesis (DO) of the rabbit mandible using stereological, radiological and immunohistochemical methods. Material and Methods DO was performed unilaterally in the mandible of 18 New Zealand rabbits (six months old, weighing between 2.5-3 kg). In the consolidation period, rabbits were divided into three groups randomly after the distraction period. The distraction zone of the mandible was received no treatment as controls (E0*2). Group 2 (E 500*2) received ESWT (twice 500 impulses at 14 kV and 0.19 mJ/mm2 energy) in the first and fourth days of the consolidation. Group 3 (E1000*2) treated with ESWT (twice 1000 impulses at 14 kV and 0.19 mJ/mm2 energy) in the first and fourth days of the consolidation period. After the sacrification, radiologically bone mineral density, new bone formation, new fibrous tissue and new vessel formation were analyzed by stereological. Results It was found a statistically significant difference between the study groups and control group in the bone mineral density measurements and the highest value was in the E1000*2 group. In the stereological analysis, new bone formation was highest in the E1000*2 group and there was a significant difference compared to the other groups (E0*2 and E500*2) (p=0.000). The lowest connective tissue volume was found in the E500*2 and there was a significant difference compared to the other groups (E0*2 and E1000*2) (p=0.000). The volume of the new vessel was highest in the E500*2 and lowest in the E0*2 group. It was found statistically significant difference between the values of the study and control groups. Conclusions Interestingly, we found that repetition of the 1000 impulses ESWT accelerated the consolidation, 500 impulses ESWT extended consolidation period of the DO. Key words:Distraction osteogenesis, extracorporeal shock waves, stereology

  13. One-repetition maximum strength test represents a valid means to assess leg strength in vivo in humans.

    Science.gov (United States)

    Verdijk, Lex B; van Loon, Luc; Meijer, Kenneth; Savelberg, Hans H C M

    2009-01-01

    Skeletal muscle strength is often determined to evaluate the adaptive response to an exercise intervention programme. Although dynamometry is considered the "gold standard" for the assessment of muscle strength in vivo, one-repetition maximum (1-RM) testing performed on training-specific equipment is more commonly applied. We assessed the validity of specific knee extension 1-RM testing by comparison with dynamometry in a heterogeneous population (n=55). All participants performed 1-RM tests on regular leg extension and leg press machines. Additionally, isometric (at seven different knee angles) and isokinetic (at four different velocities) knee extension peak torques were determined. Pearson's r was calculated for the relationship between 1-RM data and peak torques for the entire population and for subgroups defined by age and gender. One-repetition maximum strength correlated strongly with the dynamometer results. One-repetition maximum leg extension correlated more strongly with peak torques than did 1-RM leg press (0.78leg muscle strength in vivo in young and elderly men and women. Considering the importance of training specificity in strength assessment, we argue that 1-RM testing can be applied to assess changes in leg muscle strength following an exercise intervention.

  14. A Pilot Study Comparing Two Nonword Repetition Tasks for Use in a Formal Test Battery

    Science.gov (United States)

    Tattersall, Patricia J.; Nelson, Nickola Wolf; Tyler, Ann A.

    2015-01-01

    Two sets of nonwords (with and without true morphemes) were compared for their ability to differentiate students in Grades 1 through 12 with and without language impairment (36 each; N = 72) on a nonword repetition task. Results indicated that either nonword type could contribute to differential diagnosis.

  15. The shock tube as a device for testing transonic airfoils at high Reynolds numbers

    Science.gov (United States)

    Cook, W. J.; Presley, L. L.; Chapman, G. T.

    1978-01-01

    A performance analysis of gas-driven shock tubes shows that transonic airfoil flows with chord Reynolds numbers in the range of 100 million can be generated behind the primary shock in a large shock tube. A study of flow over simple airfoils has been carried out at low and intermediate Reynolds numbers to assess the testing technique. Results obtained from schlieren photos and airfoil pressure measurements show that steady transonic flows similar to those observed for the airfoils in wind tunnels can be generated within the available testing time in a shock tube with either properly-contoured test section walls or a properly-designed slotted-wall test section. The study indicates that the shock tube is a useful facility for studying two-dimensional high Reynolds number transonic airfoil flows.

  16. Anthropometry increases 1 repetition maximum predictive ability of NFL-225 test for Division IA college football players.

    Science.gov (United States)

    Hetzler, Ronald K; Schroeder, Brian L; Wages, Jennifer J; Stickley, Christopher D; Kimura, Iris F

    2010-06-01

    The purpose of this study was to compare existing 1 repetition maximum (1RM) bench press prediction equations in National Collegiate Athletic Association (NCAA) Division IA college football players and determine if the error associated with the prediction of 1RM bench press from the National Football League (NFL)-225 test could be reduced through the addition of anthropometric measurements. Anthropometric measures, 1RM bench press, NFL-225 test repetitions to fatigue, and body composition data were collected on 87 Division IA football players (mean+/-SD age 19.9+/-1.3 years; height 182.3+/-7.3 cm; body mass 102.3+/-21.1 kg; % fat 13.9+/-6.7; 1RM bench press 140.5+/-2 6.6 kg; and NFL-225 reps to fatigue 14.1+/-8.0). Hierarchical regression revealed an R=0.87 when predicting 1RM from the NFL-225 test alone, which improved to R=0.90 with the addition of the anthropometric variables: arm circumference and arm length. The following equation was the best performing model to predict 1RM bench press: 1RM (lb)=299.08+2.47 arm circumference (cm)--4.60 arm length (cm)+5.84 reps @ 225; SEE=18.3 lb). This equation predicted 43.7% of subjects' within +/-10 lb of their actual 1RM bench press. Using a crossvalidation group, the equation resulted in estimates of 1RM which were not significantly different than the actual 1RM. Because of the variability that has been shown to be associated with 1RM prediction equations, the use of actual 1RM testing is recommended when this is a critical variable. However, coaches, scouts, and athletes, who choose to estimate 1RM bench press using repetitions to failure from the NFL-225 test, may benefit from the use of the equations developed in this study to estimate 1RM bench press with the inclusion of simple anthropometric measurements.

  17. NUMERICAL MODELING OF MULTICYLINDER ELECTRO-HYDRAULIC SYSTEM AND CONTROLLER DESIGN FOR SHOCK TEST MACHINE

    Institute of Scientific and Technical Information of China (English)

    CHU Deying; ZHANG Zhiyi; WANG Gongxian; HUA Hongxing

    2007-01-01

    A high fidelity dynamic model of a high-energy hydraulically-actuated shock test machine for heavy weight devices is presented to satisfy the newly-built shock resistance standard and simulate the actual underwater explosion environments in laboratory as well as increase the testing capability of shock test machine. In order to produce the required negative shock pulse in the given time duration, four hydraulic actuators are utilized. The model is then used to formulate an advanced feedforward controller for the system to produce the required negative waveform and to address the motion synchronization of the four cylinders. The model provides a safe and easily controllable way to perform a "virtual testing" before starting potentially destructive tests on specimen and to predict performance of the system. Simulation results have demonstrated the effectiveness of the controller.

  18. 气动式振动台激振器低温失效机理研究及结构改进%Study on Performance and Optimal Design of Pneumatic Vibrator of Repetitive Shock Machine on Cold Soak Temperature

    Institute of Scientific and Technical Information of China (English)

    陶俊勇; 刘彬; 陈循

    2012-01-01

    气动式激振器是给可靠性强化试验设备气动式振动台提供激励信号的核心部件.针对气动式激振器在低温试验环境中无法工作的问题,研究其低温失效机理,建立理论分析模型;根据模型从激振器缸体材料、尺寸和内外壁温差三方面对气动式激振器结构进行优化设计,加工完成以加热膜为核心组件的气动式低温激振器样品,并给出温控方法;考察低温激振器样品的加热均匀性、加热效率和耐振性,并分别测试低温和常温环境中样品端部的激励响应.结果表明,该低温激振器样品的低温工作性能比原激振器有很大提升,能在低温环境中长时间稳定工作,且在低温和常温环境中端部的激励响应特性比较接近,验证新型低温激振器设计方案的可行性,对于拓展气动式振动台的应用范围有着积极作用.%Pneumatic vibrator, which produces excitation signals, is one of the most important part of repetitive shock machine. In low temperature condition, pneumatic vibrator cannot work as usual. In order to solve this problem, firstly the failure mechanism is studied by theory model. Then the structure of the pneumatic vibrator is ameliorated by the ways of choosing appropriate stuff and dimensions of the cylinder, and minishing the gap in temperature between the inside and outside of the cylinder. The method of controlling temperature is brought forward according to the model. Finally a pneumatic vibrator of cold temperature is made, whose durability of repetitive shock and uniformity and efficiency of calefaction is tested in low temperature conditions, and whose response characteristic of excitation on the roof is tested in low and room temperature condition, respectively. The results show that the working capability in low temperature condition of the newly designed vibrator is much better than that of the primary one, and that it can work normally and continuously in low

  19. Hypovolemic shock

    Science.gov (United States)

    ... thready Tests that may be done include: Blood chemistry, including kidney function tests and those tests looking ... severe shock. Severe hypovolemic shock may lead to death, even with immediate medical attention. Older adults are ...

  20. High repetition ration solid state switched CO2 TEA laser employed in industrial ultrasonic testing of aircraft parts

    Science.gov (United States)

    von Bergmann, Hubertus; Morkel, Francois; Stehmann, Timo

    2015-02-01

    Laser Ultrasonic Testing (UT) is an important technique for the non-destructive inspection of composite parts in the aerospace industry. In laser UT a high power, short pulse probe laser is scanned across the material surface, generating ultrasound waves which can be detected by a second low power laser system and are used to draw a defect map of the part. We report on the design and testing of a transversely excited atmospheric pressure (TEA) CO2 laser system specifically optimised for laser UT. The laser is excited by a novel solid-state switched pulsing system and utilises either spark or corona preionisation. It provides short output pulses of less than 100 ns at repetition rates of up to 1 kHz, optimised for efficient ultrasonic wave generation. The system has been designed for highly reliable operation under industrial conditions and a long term test with total pulse counts in excess of 5 billion laser pulses is reported.

  1. Numerical modeling and analysis of the mechanism of a novel shock wave regulator for impact test

    Institute of Scientific and Technical Information of China (English)

    Wang Gongxian; Zhang Zhiyi; Wang Yu

    2008-01-01

    Based on the concept of hydraulic dissipation of kinetic energy, a novel shock wave regulator, which is composed of a damper and an externally triggered valve, is presented with thorough analyses on its working mechanism. By establishing motion equations of each component of the regulator and simulating the dynamic behavior of the whole system, the shock wave regulator is demonstrated numerically to be able to change the width and amplitude of shock pulses. Prompt and easy adjustment can be achieved by changing the equivalent flow area of damping orifices and consequently the closing velocity of the flow area of a valve, which makes it applicable to different impact testing.

  2. Effects of multiple study-test repetition on the neural correlates of recognition memory: ERPs dissociate remembering and knowing

    Science.gov (United States)

    de Chastelaine, Marianne; Friedman, David; Cycowicz, Yael M.; Horton, Cort

    2009-01-01

    ERP frontal (300–500 ms) and parietal (500–700 ms) episodic memory (EM) effects are thought to reflect, respectively, familiarity and recollection. However, as most ERP studies use pre-experimentally familiar items, an alternative idea is that the frontal EM effect reflects conceptual priming. Repetition of unnameable symbols was used to assess modulations of the putative ERP indices of familiarity and recollection. The same symbols were viewed in each of 4 study/test blocks. Increases in familiarity and conceptual processing of symbols did not modulate the frontal EM effect, suggesting that it reflects neither familiarity nor conceptual priming. The magnitude of the parietal EM effect increased and its onset latency decreased across tests for items given remember (R), but not know (K) judgments. R and K old-new topographies differed. These findings support dual-process proposals that familiarity- and recollection-based processes are distinct. PMID:19055497

  3. Application of shock tubes to transonic airfoil testing at high Reynolds numbers

    Science.gov (United States)

    Cook, W. J.; Chaney, M. J.; Presley, L. L.; Chapman, G. T.

    1978-01-01

    Performance analysis of a gas-driven shock tube shows that transonic airfoil flows with chord Reynolds numbers of the order of 100 million can be produced, with limitations being imposed by the structural integrity of the facility or the model. A study of flow development over a simple circular arc airfoil at zero angle of attack was carried out in a shock tube at low and intermediate Reynolds numbers to assess the testing technique. Results obtained from schlieren photography and airfoil pressure measurements show that steady transonic flows similar to those produced for the same airfoil in a wind tunnel can be generated within the available testing time in a shock tube with properly contoured test section walls.

  4. Testing the Empirical Shock Arrival Model using Quadrature Observations

    CERN Document Server

    Gopalswamy, N; Xie, H; Yashiro, S

    2013-01-01

    The empirical shock arrival (ESA) model was developed based on quadrature data from Helios (in-situ) and P-78 (remote-sensing) to predict the Sun-Earth travel time of coronal mass ejections (CMEs) [Gopalswamy et al. 2005a]. The ESA model requires earthward CME speed as input, which is not directly measurable from coronagraphs along the Sun-Earth line. The Solar Terrestrial Relations Observatory (STEREO) and the Solar and Heliospheric Observatory (SOHO) were in quadrature during 2010 - 2012, so the speeds of Earth-directed CMEs were observed with minimal projection effects. We identified a set of 20 full halo CMEs in the field of view of SOHO that were also observed in quadrature by STEREO. We used the earthward speed from STEREO measurements as input to the ESA model and compared the resulting travel times with the observed ones from L1 monitors. We find that the model predicts the CME travel time within about 7.3 hours, which is similar to the predictions by the ENLIL model. We also find that CME-CME and CME...

  5. The Sandia MEMS Passive Shock Sensor : FY08 testing for functionality, model validation, and technology readiness.

    Energy Technology Data Exchange (ETDEWEB)

    Walraven, Jeremy Allen; Blecke, Jill; Baker, Michael Sean; Clemens, Rebecca C.; Mitchell, John Anthony; Brake, Matthew Robert; Epp, David S.; Wittwer, Jonathan W.

    2008-10-01

    This report summarizes the functional, model validation, and technology readiness testing of the Sandia MEMS Passive Shock Sensor in FY08. Functional testing of a large number of revision 4 parts showed robust and consistent performance. Model validation testing helped tune the models to match data well and identified several areas for future investigation related to high frequency sensitivity and thermal effects. Finally, technology readiness testing demonstrated the integrated elements of the sensor under realistic environments.

  6. Rocket nozzle thermal shock tests in an arc heater facility

    Science.gov (United States)

    Painter, James H.; Williamson, Ronald A.

    1986-01-01

    A rocket motor nozzle thermal structural test technique that utilizes arc heated nitrogen to simulate a motor burn was developed. The technique was used to test four heavily instrumented full-scale Star 48 rocket motor 2D carbon/carbon segments at conditions simulating the predicted thermal-structural environment. All four nozzles survived the tests without catastrophic or other structural failures. The test technique demonstrated promise as a low cost, controllable alternative to rocket motor firing. The technique includes the capability of rapid termination in the event of failure, allowing post-test analysis.

  7. Efficacy of the National Football League-225 Test to Track Changes in One Repetition Maximum Bench Press After Training in National Collegiate Athletic Association Division IA Football Players.

    Science.gov (United States)

    Mann, J Bryan; Ivey, Pat A; Stoner, Josh D; Mayhew, Jerry L; Brechue, William F

    2015-11-01

    Numerous investigations have attested to the efficacy of the National Football League (NFL)-225 test to estimate one repetition maximum (1RM) bench press. However, no studies have assessed the efficacy of the test to track changes in strength across a training program. The purpose of this study was to determine the accuracy of the NFL-225 test for determining the change in 1RM bench press in National Collegiate Athletic Association Division IA college football players after training. Over a 4-year period, players (n = 203) were assessed before and after a 6-week off-season resistance program for 1RM bench press and repetitions completed with 102.3 kg (225 lbs). Test sessions typically occurred within 1 week of each other. Players significantly increased 1RM by 4.2 ± 8.6 kg and NFL-225 repetitions by 0.9 ± 2.3, although the effect size (ES) for each was trivial (ES = 0.03 and 0.07, respectively). National Football League 225 prediction equations had higher correlations with 1RM before training (intraclass correlation coefficient [ICC] = 0.95) than after training (ICC = 0.75). The correlation between the change in NFL-225 repetitions and change in 1RM was low and negative (r = -0.22, p football players and render the NFL-225 test less effective in predicting the change in 1RM bench press strength after short-term training.

  8. A single-pulse shock tube coupled with high-repetition-rate time-of-flight mass spectrometry and gas chromatography for high-temperature gas-phase kinetics studies

    Science.gov (United States)

    Sela, P.; Shu, B.; Aghsaee, M.; Herzler, J.; Welz, O.; Fikri, M.; Schulz, C.

    2016-10-01

    Shock tubes are frequently used to investigate the kinetics of chemical reactions in the gas phase at high temperatures. Conventionally, two complementary arrangements are used where either time-resolved intermediate species measurements are conducted after the initiation of the reaction or where the product composition is determined after rapid initiation and quenching of the reaction through gas-dynamic processes. This paper presents a facility that combines both approaches to determine comprehensive information. A single-pulse shock tube is combined with high-sensitivity gas chromatography/mass spectrometry for product composition and concentration measurement as well as high-repetition-rate time-of-flight mass spectrometry for time-dependent intermediate concentration determination with 10 μs time resolution. Both methods can be applied simultaneously. The arrangement is validated with investigations of the well-documented thermal unimolecular decomposition of cyclohexene towards ethylene and 1,3-butadiene at temperatures between 1000 and 1500 K and pressures ranging from 0.8 to 2.4 bars. The comparison shows that the experimental results for both detections are in very good agreement with each other and with literature data.

  9. The Shock and Vibration Bulletin. Part 3. Skylab, Vibration Testing and Analysis

    Science.gov (United States)

    1973-06-01

    Astronautics Company, Huntington Beach, California SKYLAB PAYLOAD ASSEMBLY - VIBROACOUSTIC TEST PROGRAM ........... 43 P. Rader , Martin Marietta Corporation...NATES S. Srinivas, NASA, Langley Research Center, Hamnto i, Virginia vu OPTIMU3M PASSIVE SHOCK ISOLATION FOR UNDERGROUND PROTECTIVE STRUCTURES P. L...Newbrough, and J.R.West, Jr.,"Vibration and Acoustic Tests of the Recon- 3. P. Rader , "Skylab Payload Assembly - Vibro- figured Apollo Service

  10. Investigation of the Self-Healing Behaviors of Microcapsules/Bitumen Composites by a Repetitive Direct Tension Test

    Directory of Open Access Journals (Sweden)

    Jun-Feng Su

    2016-07-01

    Full Text Available The aim of this work was to evaluate the self-healing behaviors of bitumen using microcapsules containing rejuvenator by a modified fracture healing–refracture method through a repetitive tension test. Microcapsules had mean size values of 10, 20 and 30 μm with a same core/shell ratio of 1/1. Various microcapsules/bitumen samples were fabricated with microcapsule contents of 1.0, 3.0 and 5.0 wt. %, respectively. Tension strength values of microcapsules/bitumen samples were measured by a reparative fracture-healing process under different temperatures. It was found that these samples had tensile strength values larger than the data of pure bitumen samples under the same conditions after the four tensile fracture-healing cycles. Fracture morphology investigation and mechanism analysis indicated that the self-healing process was a process consisting of microcapsules being broken, penetrated and diffused. Moreover, the crack healing of bitumen can be considered as a viscosity driven process. The self-healing ability partly repaired the damage of bitumen during service life by comparing the properties of virgin and rejuvenated bitumen.

  11. Test-retest assessment of cortical activation induced by repetitive transcranial magnetic stimulation with brain atlas-guided optical topography

    Science.gov (United States)

    Tian, Fenghua; Kozel, F. Andrew; Yennu, Amarnath; Croarkin, Paul E.; McClintock, Shawn M.; Mapes, Kimberly S.; Husain, Mustafa M.; Liu, Hanli

    2012-11-01

    Repetitive transcranial magnetic stimulation (rTMS) is a technology that stimulates neurons with rapidly changing magnetic pulses with demonstrated therapeutic applications for various neuropsychiatric disorders. Functional near-infrared spectroscopy (fNIRS) is a suitable tool to assess rTMS-evoked brain responses without interference from the magnetic or electric fields generated by the TMS coil. We have previously reported a channel-wise study of combined rTMS/fNIRS on the motor and prefrontal cortices, showing a robust decrease of oxygenated hemoglobin concentration (Δ[HbO2]) at the sites of 1-Hz rTMS and the contralateral brain regions. However, the reliability of this putative clinical tool is unknown. In this study, we develop a rapid optical topography approach to spatially characterize the rTMS-evoked hemodynamic responses on a standard brain atlas. A hemispherical approximation of the brain is employed to convert the three-dimensional topography on the complex brain surface to a two-dimensional topography in the spherical coordinate system. The test-retest reliability of the combined rTMS/fNIRS is assessed using repeated measurements performed two to three days apart. The results demonstrate that the Δ[HbO2] amplitudes have moderate-to-high reliability at the group level; and the spatial patterns of the topographic images have high reproducibility in size and a moderate degree of overlap at the individual level.

  12. Standardized Laboratory Test Requirements for Hardening Equipment to Withstand Wave Impact Shock in Small High Speed Craft

    Science.gov (United States)

    2017-02-06

    penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR...the risk of equipment malfunction or failure due to shock forces caused by wave impacts in high-speed craft. The engineering rationale, assumptions...procurement documents are presented. 15. SUBJECT TERMS Shock Wave slam shock test equipment operability risk reduction 16. SECURITY

  13. Research on Simulation and Test of the Nonlinear Responses for the Hydraulic Shock Absorber

    Institute of Scientific and Technical Information of China (English)

    张建武; 刘延庆

    2003-01-01

    Basically on the multi-body system dynamics,the virtual prototype of the hydraulic shock absorber for the bench test is developed in the ADAMS environment.Dynamic behaviors of the absorber are studied by both computer simulation and real test.Numerical predictions of dynamic responses are produced by the established virtual prototype of the absorber and compared with experimental results.It has been shown from the comparison that the vibration behaviors of the prototype with hysteretic damping characteristics are considered to be more identical with the bench test results than those of the same prototype with piecewise linear damping properties are.The current virtual prototype of the shock absorber is correct and can be a developing terrace for the optimizing design of the absorber and matching capability of the whole car.

  14. Molecular Line Emission from Multifluid Shock Waves. I. Numerical Methods and Benchmark Tests

    Science.gov (United States)

    Ciolek, Glenn E.; Roberge, Wayne G.

    2013-05-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part, independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other, equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are Lt magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests confirming its accuracy are presented, including (1) MHD wave packets ranging over orders of magnitude in length- and timescales, (2) early evolution of multifluid shocks caused by two colliding clouds, and (3) a multifluid shock with mass transfer between the fluids by cosmic-ray ionization and ion-electron recombination, demonstrating the effect of ion mass loading on magnetic precursors of MHD shocks. An exact solution to an MHD Riemann problem forming the basis for an approximate numerical solver used in the homogeneous part of our scheme is presented, along with derivations of the analytic benchmark solutions and tests showing the convergence of the numerical algorithm.

  15. MOLECULAR LINE EMISSION FROM MULTIFLUID SHOCK WAVES. I. NUMERICAL METHODS AND BENCHMARK TESTS

    Energy Technology Data Exchange (ETDEWEB)

    Ciolek, Glenn E.; Roberge, Wayne G., E-mail: cioleg@rpi.edu, E-mail: roberw@rpi.edu [New York Center for Astrobiology (United States); Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States)

    2013-05-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part, independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other, equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are << magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests confirming its accuracy are presented, including (1) MHD wave packets ranging over orders of magnitude in length- and timescales, (2) early evolution of multifluid shocks caused by two colliding clouds, and (3) a multifluid shock with mass transfer between the fluids by cosmic-ray ionization and ion-electron recombination, demonstrating the effect of ion mass loading on magnetic precursors of MHD shocks. An exact solution to an MHD Riemann problem forming the basis for an approximate numerical solver used in the homogeneous part of our scheme is presented, along with derivations of the analytic benchmark solutions and tests showing the convergence of the numerical algorithm.

  16. Test of a new heat-flow equation for dense-fluid shock waves.

    Science.gov (United States)

    Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

    2010-09-21

    Using a recently proposed equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, we model shockwave propagation in the dense Lennard-Jones fluid. Disequilibrium among the three components of temperature, namely, the difference between the kinetic temperature in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, gives rise to a new transport (equilibration) mechanism not seen in usual one-dimensional heat-flow situations. The modification of the heat-flow equation was tested earlier for the case of strong shock waves in the ideal gas, which had been studied in the past and compared to Navier-Stokes-Fourier solutions. Now, the Lennard-Jones fluid, whose equation of state and transport properties have been determined from independent calculations, allows us to study the case where potential, as well as kinetic contributions are important. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations under strong shock wave conditions, compared to Navier-Stokes.

  17. Evaluation of repetitive stimulation test (RST in 30 patients with Myasthenia Gravis, who were previously confirmed by clinical sign and tensilon test 1996-99

    Directory of Open Access Journals (Sweden)

    "Ghabaee M

    2001-07-01

    Full Text Available est (RST is the most commonly used electrodiagnostic test to asses the defect of neuromuscular transmission, which is reported to be positive in the diffuse and restricted ocular forms 60-95% and 14-50%, respectively. In a cross-sectional study, to determine the efficacy of repetitive stimulation test in myasthenia gravis, we evaluated the results in 30 cases who were hospitalized in Imam Khomeini Hospital during 1996-1999. Patients were first selected clinically and then confirmed by Tensilon test.Various clinical types including generalized and restricted ocular forms with different severity and duration were entered in this study. Considering the fact that the positiveness of the test is enhanced by assessment of more muscle groups, we evaluated decremental response in the facial, proximal and distal muscles of limbs. 90% of patients had the generalized form of the disease, whereas ocular myasthenia gravis was seen only in 10% of the cases. 74% of females and 73% of males showed positive response (overall: 73.3%. No significant association was found between the positive response, and age and sex. Peaks of incidences of the disease for the males were in fourth and sixth decades and for the females in thired decades

  18. High-repetition-rate compact excimer laser: UV light source for metrology, inspection, direct writing, and material testing

    Science.gov (United States)

    Huber, Heinz P.; Pflanz, Tobias; Goertler, Andreas; Schillinger, Helmut

    2003-06-01

    The discharge pumped excimer laser is a gas laser providing ultra violet (UV) radiation with well defined spectral, temporal and spatial properties. The fast development of excimer lasers in recent years has succeeded in designing very compact, table-top and turn-key systems delivering up to 20 W of radiation at 248 nm, 10 W at 193 nm and 2 W at 157 nm with repetition rates up to 2000 Hz (1, 5). Due to their short emission wavelength and compactness they are continuously replacing other light sources, like lamps and ion lasers, in applications as metrology, inspection, direct writing and material testing. Spatial and temporal beam properties of compact excimer lasers are very suitable to be utilized as illumination source in these applications. The compact excimer laser is combining the advantages of both, lamp and laser sources. It displays low temporal and spatial coherence, but has a narrow spectral emission range of a few hundred pm. The beam area is approximately 1/2 cm2, the divergence is in the order of 1 mrad. Variation of beam position and beam direction are negligible for most illumination applications. Compact excimer lasers are easy to integrate in measurement and inspection systems. Typically their footprint area is 0.25 m2. The power consumption is less than 1 kW, enabling single phase electrical supply and air cooling. State-of-the-art compact excimer lasers are compliant to all relevant SEMI regulations. The laser optics exceeds the life time of the laser tube, thus no optics cleaning and exchange is necessary in a whole life time of a laser tube of a few billion pulses (6).

  19. NASTRAN Analysis Comparison to Shock Tube Tests Used to Simulate Nuclear Overpressures

    Science.gov (United States)

    Wheless, T. K.

    1985-01-01

    This report presents a study of the effectiveness of the NASTRAN computer code for predicting structural response to nuclear blast overpressures. NASTRAN's effectiveness is determined by comparing results against shock tube tests used to simulate nuclear overpressures. Seven panels of various configurations are compared in this study. Panel deflections are the criteria used to measure NASTRAN's effectiveness. This study is a result of needed improvements in the survivability/vulnerability analyses subjected to nuclear blast.

  20. The Shock and Vibration Bulletin. Part 3. Vibration Testing, Instrumentation and Data Analysis, Loads and Environments.

    Science.gov (United States)

    1977-09-01

    Mathews, B.W. Duggin, Sandia Laboratories, Albuquerque, NM SHOCK WAVEFORM TESTING ON AN ELECTRODYNAMIC VIBRATOR W.E. Frain, Applied Physics Laboratory, The...when tuned to 260 Hz at ambient RESPONSE OF GUITAR FIXTURE pressure and 1000 Hz at maximum pres- sure. The operational range of this de- by strings and...frequency. The strings used are tion, for a variation over the entire guitar strings and are installed at a S S pressure range. slight angle, as

  1. Thermal Shock test of Helium tank for HL-LHC crab cavities

    CERN Multimedia

    2017-01-01

    Thermal shock test of the prototype of the helium tank for the HL-LHC crab cavities. We put the tank in a bath of liquid nitrogen so that it goes from 300 K to 77 K in ~1 hr. We had some sensors inside to make sure the loads and the deformations are not too big. The tank is then put back in the air and heated up. We do this cycle 5 times ato validate the design made for this device. Before this test we run a pressure test (we put a higher pressure inside).

  2. Influence of shock wave pressure amplitude and pulse repetition frequency on the lifespan, size and number of transient cavities in the field of an electromagnetic lithotripter

    Science.gov (United States)

    Huber, Peter; Jöchle, Knut; Debus, Jürgen

    1998-10-01

    Monitoring the generation of cavitation is of great interest for diagnostic and therapeutic use of ultrasound in medicine, since cavitation is considered to play a major role in nonthermal ultrasound interactions with tissue. Important parameters are the number of cavitation events and the energy released during the bubble collapse. This energy is correlated to the maximum bubble radius which is related to the cavitation lifespan. The aim of this study was therefore to investigate the influence of the acoustic pressure amplitude and the pulse repetition frequency (PRF) in the field of a lithotripter (Lithostar, Siemens) on the number, size and lifespan of transient cavitation bubbles in water. We used scattered laser light recorded by a photodiode and stroboscopic photographs to monitor the cavitation activity. We found that PRF (range 0.5-5 Hz) had no influence on the cavitation bubble lifespan and size, whereas lifespan and size increased with the acoustic pressure amplitude. In contrast, the number of cavitation events strongly increased with PRF, whereas the pressure amplitude had no significant influence on the number of cavitation events. Thus, by varying the pressure amplitude and PRF, it might be possible to deliver a defined relative number of cavitations at a defined relative energy level in a defined volume. This seems to be relevant to further studies that address the biological effects of transient cavitation occurring in the fields of lithotripters.

  3. Testing of super conducting low-beta 704 Mhz cavities at 50 Hz pulse repetition rate in view of SPL- first results

    CERN Document Server

    Höfle, W; Lollierou, J; Valuch, D; Chel, S; Devanz, G; Desmons, M; Piquet, O; Paparella, R; Pierini, P

    2010-01-01

    In the framework of the preparatory phase for the luminosity upgrade of the LHC (SLHC-PP ) it is foreseen to characterize two superconducting RF cavities and demonstrate compliance of the required SPL field stability in amplitude and phase using a prototype LLRF system. We report on the preparation for testing of two superconducting low-beta cavities at 50 Hz pulse repetition rate including the setting-up of the low level RF control system to evaluate the performance of the piezo-tuning system and cavity field stability in amplitude and phase. Results from tests with 50 Hz pulse repetition rate are presented. Simulations of the RF system will be used to predict the necessary specifications for power and bandwidth to control the cavity field and derive specifications for the RF system and its control. Exemplary results of the simulation are presented.

  4. The effects of shock wave and quasi-traveling wave in the mechanical impact test

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    It is well-known that the numerical value is always larger than the measured value,amounting to many times,if we calculate the stress of the specimen in the impulse test using the NASTRAN and ANSYS (N-A) software.We believe that the impact induces shock wave or quasi-traveling wave in the specimen,which can qualitatively explain the discrepancy of the two values.In order to verify it,the Lax-Friedrichs (L-F) scheme is taken to simulate the transmission of shock wave and quasi-traveling wave in solid.Numerical results show that the action area of the stress wave is small and the action time is very short,so the resulting stress and actual work are not big.In addition,the distribution of the impact values obtained by the numerical simulation is in accordance with the trend of the measured impact values.

  5. Molecular Line Emission from Multifluid Shock Waves. I. Numerical Methods and Benchmark Tests

    CERN Document Server

    Ciolek, Glenn E

    2013-01-01

    We describe a numerical scheme for studying time-dependent, multifluid, magnetohydrodynamic shock waves in weakly ionized interstellar clouds and cores. Shocks are modeled as propagating perpendicular to the magnetic field and consist of a neutral molecular fluid plus a fluid of ions and electrons. The scheme is based on operator splitting, wherein time integration of the governing equations is split into separate parts. In one part independent homogeneous Riemann problems for the two fluids are solved using Godunov's method. In the other equations containing the source terms for transfer of mass, momentum, and energy between the fluids are integrated using standard numerical techniques. We show that, for the frequent case where the thermal pressures of the ions and electrons are << magnetic pressure, the Riemann problems for the neutral and ion-electron fluids have a similar mathematical structure which facilitates numerical coding. Implementation of the scheme is discussed and several benchmark tests ...

  6. COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. I. NEUTRAL RETURN FLUX AND ITS EFFECTS ON ACCELERATION OF TEST PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Blasi, P.; Morlino, G.; Bandiera, R.; Amato, E. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, I-50125 Firenze (Italy); Caprioli, D. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08540 (United States)

    2012-08-20

    A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged and neutral particles both upstream and downstream of the shock. In particular, neutrals that suffer a charge exchange downstream with shock-heated ions generate high-velocity neutrals that have a finite probability of returning upstream. These neutrals might then deposit heat in the upstream plasma through ionization and charge exchange, thereby reducing the fluid Mach number. A consequence of this phenomenon, which we refer to as the neutral return flux, is a reduction of the shock compression factor and the formation of a shock precursor upstream. The scale length of the precursor is determined by the ionization and charge-exchange interaction lengths of fast neutrals moving toward upstream infinity. In the case of a shock propagating in the interstellar medium, the effects of ion-neutral interactions are especially important for shock velocities <3000 km s{sup -1}. Such propagation velocities are common among shocks associated with supernova remnants, the primary candidate sources for the acceleration of Galactic cosmic rays. We then investigate the effects of the return flux of neutrals on the spectrum of test particles accelerated at the shock. We find that, for shocks slower than {approx}3000 km s{sup -1}, the particle energy spectrum steepens appreciably with respect to the naive expectation for a strong shock, namely, {proportional_to}E{sup -2}.

  7. Development of a Marslander with crushable shock absorber by virtual and experimental testing

    Science.gov (United States)

    Schröder, Silvio; Reinhardt, B.; Brauner, C.; Gebauer, I.; Buchwald, R.

    2017-05-01

    Since the beginning of space exploration, probes have been sent to other planets or moons with the associated challenge of landing on these bodies. For a soft landing several damping methods like landing legs or airbags have been used. A new and potentially less complex and lighter way to reduce the shock loads at touchdown is the use of a crushable shield underneath the lander platform. This crushable shield could be made for example out of an energy absorbing materials like an aluminum honeycomb core with a High Performance Polyethylene cover sheet. The design is particularly advantageous since no moving parts nor other mechanisms are required, thus making the shield very robust and fail safe. The only mission that has used this technique is the ESA/Roscosmos-mission ;ExoMars; which started in 2016. The development of such a crushable shock absorber implies and requires assessment of materials, manufacturing processes, the setup of a numerical simulation and the experimental validation in a test lab. In an independent research project (Marslander) a representative engineering mockup of the landing platform has been built and tested at the Landing & Mobility Test Facility (LAMA) to support the numerical simulation model with experimental data. This paper is focusing on the hardware tests. Results of the above stated development and testing processes will be presented and discussed.

  8. Oxygen challenge test in septic shock patients: prognostic value and influence of respiratory status.

    Science.gov (United States)

    Mari, Arnaud; Vallée, Fabrice; Bedel, Jérome; Riu, Béatrice; Ruiz, Jean; Sanchez-Verlaan, Pascale; Geeraerts, Thomas; Génestal, Michèle; Silva, Stein; Fourcade, Olivier

    2014-06-01

    Transcutaneous oxygen pressure (PtcO2) value in response to an increase of FiO2 or oxygen challenge test (OCT) in ventilated patients has been reported to be related to peripheral perfusion and outcome during septic shock. However, patients with sepsis-related acute respiratory distress syndrome could demonstrate compromised arterial oxygenation with OCT impairment decoupled to circulatory failure. The aims of this study were to confirm the prognostic value of OCT and to explore the influence of respiratory status on OCT results. This was a prospective study set in an intensive care unit of a tertiary teaching hospital. Fifty-six mechanically ventilated patients with septic shock criteria were studied. Transcutaneous oxygen pressure was measured at baseline and after OCT, at intensive care unit admittance (T0), and 24 h later (T24). Survival at day 28 and hemodynamic and respiratory parameters were analyzed and compared according to outcome and respiratory status. Central hemodynamic parameters or static transcutaneous data did not differ between survivors and nonsurvivors at enrollment. The OCT was statistically different at T24 according to outcome (P < 0.001), but sensitivity was low (53%). Moreover, patients with low OCT results at T24 exhibited more severe respiratory failure (P < 0.01). The OCT at T24 is related to outcome but is influenced by the severity of respiratory failure. Our results suggest considering with caution hemodynamic management based on OCT in septic shock patients with altered pulmonary function.

  9. Retroreflective Background Oriented Schlieren Imaging Results from the NASA Plume/Shock Interaction Test

    Science.gov (United States)

    Smith, Nathanial T.; Durston, Donald A.; Heineck, James T.

    2017-01-01

    In support of NASA's Commercial Supersonics Technology (CST) project, a test was conducted in the 9-by-7 ft. supersonic section of the NASA Ames Unitary Plan Wind Tunnel (UPWT). The tests were designed to study the interaction of shocks with a supersonic jet characteristic of those that may occur on a commercial supersonic aircraft. Multiple shock generating geometries were tested to examine the interaction dynamics as they pertain to sonic boom mitigation. An integral part of the analyses of these interactions are the interpretation of the data generated from the retroreflective Background Oriented Schlieren (RBOS) imaging technique employed for this test. The regularization- based optical flow methodology used to generate these data is described. Sample results are compared to those using normalized cross-correlation. The reduced noise, additional feature detail, and fewer false artifacts provided by the optical flow technique produced clearer time-averaged images, allowing for better interpretation of the underlying flow phenomena. These images, coupled with pressure signatures in the near field, are used to provide an overview of the detailed interaction flowfields.

  10. Titan IIIC Transtage/Stage 2 Separation-Shock Bench Test. Volume 3

    Science.gov (United States)

    1975-11-01

    2 6 15o I Frequency, HzJ Bench Shock Test - Stage II/III Separation, Run 10Measurement No. 4 - Longitudinal axis longeron nearstation 117 !• , 149 A...6I 5 5 4 33 3 10CC- O-10 I--L 87 8 i5 5 : -- 6 1ench Sh c- es -t ge I / I Se a a i n Ru02 1 2~w Me srm n No L N Lo g td n l0xsIn eo

  11. Shock adhesion test for composite bonded assembly using a high pulsed power generator

    Science.gov (United States)

    Gay, E.; Berthe, L.; Buzaud, E.; Boustie, M.; Arrigoni, M.

    2013-07-01

    In a context of the rising use of composite assemblies in aeronautic or defense fields, the assessment of their strength is a key issue. The method developed in this study attempts to provide solutions. A shock adhesion test based on short compressive loads, obtained by a high pulsed power generator, is proposed as a proof test to ensure the quality of composite bonded assemblies. A calibrated load induces a local tensile stress able to damage the bond interface. The high pulsed power source is the GEnerateur de Pression Isentropique device (Isentropic Pressure Generator), used to generate the required stresses, with a 450 ns pulse duration to test assemblies above the mm thickness range. The understanding of the mechanisms of wave propagation and tensile stress generation within these multilayer assemblies are scientific challenges. The ability of the technique to induce a tensile stress able to disbond the laminates and the assemblies is demonstrated. This paper details the response of carbon epoxy laminates and their bonded assemblies to a shock loading near the damage threshold.

  12. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-10-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable␣interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  13. Impact of Isothermal Aging and Testing Temperature on Large Flip-Chip BGA Interconnect Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Guirguis, Cherif; Akinade, Kola

    2017-06-01

    The stability of solder interconnects in a mechanical shock environment is crucial for large body size flip-chip ball grid array (FCBGA) electronic packages. Additionally, the junction temperature increases with higher electric power condition, which brings the component into an elevated temperature environment, thus introducing another consideration factor for mechanical stability of interconnection joints. Since most of the shock performance data available were produced at room temperature, the effect of elevated temperature is of interest to ensure the reliability of the device in a mechanical shock environment. To achieve a stable interconnect in a dynamic shock environment, the interconnections must tolerate mechanical strain, which is induced by the shock wave input and reaches the particular component interconnect joint. In this study, large body size (52.5 × 52.5 mm2) FCBGA components assembled on 2.4-mm-thick boards were tested with various isothermal pre-conditions and testing conditions. With a heating element embedded in the test board, a test temperature range from room temperature to 100°C was established. The effects of elevated temperature on mechanical shock performance were investigated. Failure and degradation mechanisms are identified and discussed based on the microstructure evolution and grain structure transformations.

  14. Prognostic value of brachioradialis muscle oxygen saturation index and vascular occlusion test in septic shock patients.

    Science.gov (United States)

    Marín-Corral, J; Claverias, L; Bodí, M; Pascual, S; Dubin, A; Gea, J; Rodriguez, A

    2016-05-01

    To compare rSO2 (muscle oxygen saturation index) static and dynamic variables obtained by NIRS (Near Infrared Spectroscopy) in brachioradialis muscle of septic shock patients and its prognostic implications. Prospective and observational study. Intensive care unit. Septic shock patients and healthy volunteers. The probe of a NIRS device (INVOS 5100) was placed on the brachioradialis muscle during a vascular occlusion test (VOT). Baseline, minimum and maximum rSO2 values, deoxygenation rate (DeOx), reoxygenation slope (ReOx) and delta value. Septic shock patients (n=35) had lower baseline rSO2 (63.8±12.2 vs. 69.3±3.3%, p<0.05), slower DeOx (-0.54±0.31 vs. -0.91±0.35%/s, p=0.001), slower ReOx (2.67±2.17 vs. 9.46±3.5%/s, p<0.001) and lower delta (3.25±5.71 vs. 15.1±3.9%, p<0.001) when compared to healthy subjects (n=20). Among septic shock patients, non-survivors showed lower baseline rSO2 (57.0±9.6 vs. 69.8±11.3%, p=0.001), lower minimum rSO2 (36.0±12.8 vs. 51.3±14.8%, p<0.01) and lower maximum rSO2 values (60.6±10.6 vs. 73.3±11.2%, p<0.01). Baseline rSO2 was a good mortality predictor (AUC 0.79; 95%CI: 0.63-0.94, p<0.01). Dynamic parameters obtained with VOT did not improve the results. Septic shock patients present an important alteration of microcirculation that can be evaluated by NIRS with prognostic implications. Monitoring microvascular reactivity in the brachioradialis muscle using VOT with our device does not seem to improve the prognostic value of baseline rSO2. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  15. [Evaluation of the risk related to repetitive work activities: testing of several methods proposed in the literature].

    Science.gov (United States)

    Capodaglio, E M; Facioli, M; Bazzini, G

    2001-01-01

    Pathologies due to the repetitive activity of the upper limbs constitutes a growing part of the work-related musculo-skeletal disorders. At the moment, there are no universally accepted and validated methods for the description and assessment of the work-related risks. Yet, the criteria fundamentally characterizing the exposure are rather clear and even. This study reports a practical example of the application of some recent risk assessment methods proposed in the literature, combining objective and subjective measures obtained on the field, with the traditional activity analysis.

  16. The one repetition maximum test and the sit-to-stand test in the assessment of a specific pulmonary rehabilitation program on peripheral muscle strength in COPD patients

    Directory of Open Access Journals (Sweden)

    Zanini A

    2015-11-01

    Full Text Available Andrea Zanini,1,2 Marina Aiello,3 Francesca Cherubino,1 Elisabetta Zampogna,1 Andrea Azzola,4 Alfredo Chetta,3 Antonio Spanevello1,5 1Division of Pneumology, IRCCS Rehabilitation Institute of Tradate, Salvatore Maugeri Foundation, Tradate, Italy; 2Division of Internal and Respiratory Medicine, Malcantonese Hospital, Giuseppe Rossi Foundation, Castelrotto, Switzerland; 3Respiratory Disease and Lung Function Unit, Department of Clinical and Experimental Medicine, University of Parma, Padiglione Rasori, Parma, Italy; 4Division of Pneumology, Department of Internal Medicine, Ospedale Civico, Lugano, Switzerland; 5Department of Clinical and Experimental Medicine, University of Insubria, Varese, Italy Background: Individuals with COPD may present reduced peripheral muscle strength, leading to impaired mobility. Comprehensive pulmonary rehabilitation (PR should include strength training, in particular to lower limbs. Furthermore, simple tools for the assessment of peripheral muscle performance are required.Objectives: To assess the peripheral muscle performance of COPD patients by the sit-to-stand test (STST, as compared to the one-repetition maximum (1-RM, considered as the gold standard for assessing muscle strength in non-laboratory situations, and to evaluate the responsiveness of STST to a PR program.Methods: Sixty moderate-to-severe COPD inpatients were randomly included into either the specific strength training group or into the usual PR program group. Patients were assessed on a 30-second STST and 1-minute STST, 1-RM, and 6-minute walking test (6MWT, before and after PR. Bland–Altman plots were used to evaluate the agreement between 1-RM and STST. Results: The two groups were not different at baseline. In all patients, 1-RM was significantly related to the 30-second STST (r=0.48, P<0.001 and to 1-minute STST (r=0.36, P=0.005. The 30-second STST was better tolerated in terms of the perceived fatigue (P=0.002 and less time consuming (P<0

  17. Rail Shock and Vibration Pre-Test Modeling of a Used Nuclear Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Steven B.; Klymyshyn, Nicholas A.; Jensen, Philip J.; Best, Ralph E.; Maheras, Steven J.; McConnell, Paul E.; Orchard, John

    2015-04-01

    The U.S. Department of Energy Office of Nuclear Energy (DOE-NE), Office of Fuel Cycle Technology, has established the Used Fuel Disposition Campaign (UFDC) to conduct the research and development activities related to storage, transportation, and disposal of used nuclear fuel (UNF) and high-level radioactive waste (HLW). The mission of the UFDC is to identify alternatives and conduct scientific research and technology development to enable storage, transportation and disposal of used nuclear fuel and HLW generated by existing and future nuclear fuel cycles. The Storage and Transportation staff within the UFDC is responsible for addressing issues regarding the long-term or extended storage (ES) of UNF and its subsequent transportation. Available information is not sufficient to determine the ability of ES UNF, including high-burnup fuel, to withstand shock and vibration forces that could occur when the UNF is shipped by rail from nuclear power plant sites to a storage or disposal facility. There are three major gaps in the available information – 1) the forces that UNF assemblies would be subjected to when transported by rail, 2) the mechanical characteristics of fuel rod cladding, which is an essential structure for controlling the geometry of the UNF, a safety related feature, and 3) modeling methodologies to evaluate multiple possible degradation or damage mechanisms over the UNF lifetime. In order to address the first gap, options for tests to determine the physical response of surrogate UNF assemblies subjected to shock and vibration forces that are expected to be experienced during normal conditions of transportation (NCT) by rail must be identified and evaluated. The objective of the rail shock and vibration tests is to obtain data that will help researchers understand the mechanical loads that ES UNF assemblies would be subjected to under normal conditions of transportation and to fortify the computer modeling that will be necessary to evaluate the impact

  18. Research on the Random Shock Vibration Test Based on the Filter-X LMS Adaptive Inverse Control Algorithm

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2016-01-01

    Full Text Available The related theory and algorithm of adaptive inverse control were presented through the research which pointed out the adaptive inverse control strategy could effectively eliminate the noise influence on the system control. Proposed using a frequency domain filter-X LMS adaptive inverse control algorithm, and the control algorithm was applied to the two-exciter hydraulic vibration test system of random shock vibration control process and summarized the process of the adaptive inverse control strategies in the realization of the random shock vibration test. The self-closed-loop and field test show that using the frequency-domain filter-X LMS adaptive inverse control algorithm can realize high precision control of random shock vibration test.

  19. Prospective Testing and Redesign of a Temporal Biomarker Based Risk Model for Patients With Septic Shock: Implications for Septic Shock Biology

    Directory of Open Access Journals (Sweden)

    Hector R. Wong

    2015-12-01

    Full Text Available The temporal version of the pediatric sepsis biomarker risk model (tPERSEVERE estimates the risk of a complicated course in children with septic shock based on biomarker changes from days 1 to 3 of septic shock. We validated tPERSEVERE performance in a prospective cohort, with an a priori plan to redesign tPERSEVERE if it did not perform well. Biomarkers were measured in the validation cohort (n = 168 and study subjects were classified according to tPERSEVERE. To redesign tPERSEVERE, the validation cohort and the original derivation cohort (n = 299 were combined and randomly allocated to training (n = 374 and test (n = 93 sets. tPERSEVERE was redesigned using the training set and CART methodology. tPERSEVERE performed poorly in the validation cohort, with an area under the curve (AUC of 0.67 (95% CI: 0.58–0.75. Failure analysis revealed potential confounders related to clinical characteristics. The redesigned tPERSEVERE model had an AUC of 0.83 (0.79–0.87 and a sensitivity of 93% (68–97 for estimating the risk of a complicated course. Similar performance was seen in the test set. The classification tree segregated patients into two broad endotypes of septic shock characterized by either excessive inflammation or immune suppression.

  20. Shock tube design for high intensity blast waves for laboratory testing of armor and combat materiel

    Directory of Open Access Journals (Sweden)

    Elijah Courtney

    2014-06-01

    Full Text Available Shock tubes create simulated blast waves which can be directed and measured to study blast wave effects under laboratory conditions. It is desirable to increase available peak pressure from ∼1 MPa to ∼5 MPa to simulate closer blast sources and facilitate development and testing of personal and vehicle armors. Three methods are experimentally investigated to increase peak simulated blast pressure produced by an oxy-acetylene driven shock tube while maintaining suitability for laboratory studies. The first method is the addition of a Shchelkin spiral priming section which supports a deflagration to detonation transition. This approach increases the average peak pressure from 1.17 MPa to 5.33 MPa while maintaining a relevant pressure-time curve (near Friedlander waveform. The second method is a bottleneck between the driving and driven sections. Coupling a 79 mm diameter driving section to a 53 mm driven section increases the peak pressure from 1.17 MPa to 2.25 MPa. A 103 mm driving section is used to increase peak pressure to 2.64 MPa. The third method, adding solid fuel to the driving section with the oxy-acetylene, results in a peak pressure increasing to 1.70 MPa.

  1. Shock tube design for high intensity blast waves for laboratory testing of armor and combat materiel

    Institute of Scientific and Technical Information of China (English)

    Elijah COURTNEY; Amy COURTNEY; Michael COURTNEY

    2014-01-01

    Shock tubes create simulated blast waves which can be directed and measured to study blast wave effects under laboratory conditions. It is desirable to increase available peak pressure from w1 MPa to w5 MPa to simulate closer blast sources and facilitate development and testing of personal and vehicle armors. Three methods are experimentally investigated to increase peak simulated blast pressure produced by an oxy-acetylene driven shock tube while maintaining suitability for laboratory studies. The first method is the addition of a Shchelkin spiral prim-ing section which supports a deflagration to detonation transition. This approach increases the average peak pressure from 1.17 MPa to 5.33 MPa while maintaining a relevant pressure-time curve (near Friedlander waveform). The second method is a bottleneck between the driving and driven sections. Coupling a 79 mm diameter driving section to a 53 mm driven section increases the peak pressure from 1.17 MPa to 2.25 MPa. A 103 mm driving section is used to increase peak pressure to 2.64 MPa. The third method, adding solid fuel to the driving section with the oxy-acetylene, results in a peak pressure increasing to 1.70 MPa.

  2. Novel method for estimating the dynamic characteristics of pressure sensor in shock tube calibration test.

    Science.gov (United States)

    Li, Qiang; Wang, Zhongyu; Wang, Zhuoran; Yan, Hu

    2015-06-01

    A shock tube is usually used to excite the dynamic characteristics of the pressure sensor used in an aircraft. This paper proposes a novel estimation method for determining the dynamic characteristic parameters of the pressure sensor. A preprocessing operation based on Grey Model [GM(1,1)] and bootstrap method (BM) is employed to analyze the output of a calibrated pressure sensor under step excitation. Three sequences, which include the estimated value sequence, upper boundary, and lower boundary, are obtained. The processing methods on filtering and modeling are used to explore the three sequences independently. The optimal estimated, upper boundary, and lower boundary models are then established. The three models are solved, and a group of dynamic characteristic parameters corresponding to the estimated intervals are obtained. A shock tube calibration test consisting of two experiments is performed to validate the performance of the proposed method. The results show that the relative errors of the dynamic characteristic parameters of time and frequency domains do not exceed 9% and 10%, respectively. Moreover, the nominal and estimated values of the parameters fall into the estimated intervals limited by the upper and lower values.

  3. Shock Tube Design for High Intensity Blast Waves for Laboratory Testing of Armor and Combat Materiel

    CERN Document Server

    Courtney, Elijah; Courtney, Michael

    2015-01-01

    Shock tubes create simulated blast waves which can be directed and measured to study blast wave effects under laboratory conditions. It is desirable to increase available peak pressure from ~1 MPa to ~5 MPa to simulate closer blast sources and facilitate development and testing of personal and vehicle armors. Three methods were investigated to increase peak simulated blast pressure produced by an oxy-acetylene driven shock tube while maintaining suitability for laboratory studies. The first method is the addition of a Shchelkin spiral priming section which works by increasing the turbulent flow of the deflagration wave, thus increasing its speed and pressure. This approach increased the average peak pressure from 1.17 MPa to 5.33 MPa while maintaining a relevant pressure-time curve (Friedlander waveform). The second method is a bottleneck between the driving and driven sections. Coupling a 79 mm diameter driving section to a 53 mm driven section increased the peak pressure from 1.17 MPa to 2.25 MPa. Using a 1...

  4. Microelectronics Instrument Products Shock and Vibration Electro-optics: C-Qualification Test Report

    Science.gov (United States)

    1994-01-01

    In this test report all measurements made during testing are recorded in ATP 20049 DS data sheets and are included in the log. The motor/encoder (henceforth referred to as the UUT) test sequence began with a baseline functional evaluation, which demonstrated that the motor satisfied the operating torque, cogging torque, winding resistance, and mechanical requirements of SOW. In addition, the encoder electrical requirements were verified, as well as the alignment of the encoder outputs relative tc, the motor shaft position. There were no discrepancies observed in this portion of the test. The UUT was then exposed to a number of environments, including thermal vacuum, thermal cycling, random and sine vibration, and mechanical shock. During the thermal environments, the performance of the UUT under load was verified at specified points in the cycles, as described in ATP 20049. In addition, the UUT was bench tested between the two thermal environments. No anomalies were observed during the thermal tests. The load attachment method was subsequently corrected, and vibration of S/N 0002 began while 0003 was being repaired.

  5. An analytical test case for dust dynamics during a shock-wave passage

    CERN Document Server

    Mattsson, Lars

    2016-01-01

    An exact solution of a forced Burgers' equation representing the dynamics of a "dust fluid" in a one-dimensional flow is presented. The test case considered starts with a steady (time independent) two-fluid flow in one dimension, where the two fluid components represent gas and dust. It is then assumed that a shock wave travels through the gas at a constant speed and without radiative energy losses and diffusion. Then, adopting a constant stopping time for the dust particles in the dust fluid (mono-dispersed grain sizes), the equation of motion for the dust fluid can be transformed into a simple ordinary differential equation, which is satisfied by the Wright omega function. Implications for the formation of detached shells around carbon stars are briefly discussed.

  6. Endogenous Versus Exogenous Shocks in Complex Networks: An Empirical Test Using Book Sale Rankings

    Science.gov (United States)

    Sornette, D.; Deschâtres, F.; Gilbert, T.; Ageon, Y.

    2004-11-01

    We study the precursory and recovery signatures accompanying shocks in complex networks, that we test on a unique database of the Amazon.com ranking of book sales. We find clear distinguishing signatures classifying two types of sales peaks. Exogenous peaks occur abruptly and are followed by a power law relaxation, while endogenous peaks occur after a progressively accelerating power law growth followed by an approximately symmetrical power law relaxation which is slower than for exogenous peaks. These results are rationalized quantitatively by a simple model of epidemic propagation of interactions with long memory within a network of acquaintances. The observed relaxation of sales implies that the sales dynamics is dominated by cascades rather than by the direct effects of news or advertisements, indicating that the social network is close to critical.

  7. Experience with helium leak and thermal shocks test of SST-1 cryo components

    Science.gov (United States)

    Sharma, Rajiv; Nimavat, Hiren; Srikanth, G. L. N.; Bairagi, Nitin; Shah, Pankil; Tanna, V. L.; Pradhan, S.

    2012-11-01

    A steady state superconducting Tokamak SST-1 is presently under its assembly stage at the Institute for Plasma Research. The SST-1 machine is a family of Superconducting SC coils for both Toroidal field and Poloidal Field. An ultra high vacuum compatible vacuum vessel, placed in the bore of the TF coils, houses the plasma facing components. A high vacuum cryostat encloses all the SC coils and the vacuum vessel. Liquid Nitrogen (LN2) cooled thermal shield between the vacuum vessel & SC coils as well as between cryostat and the SC coils. There are number of crucial cryogenic components as Electrical isolators, 80 K thermal shield, Cryogenic flexible hose etc., which have to be passed the performance validation tests as part of fulfillment of the stringent QA/QC before incorporated in the main assembly. The individual leak tests of components at RT as well as after thermal cycle from 300 K to 77 K ensure us to make final overall leak proof system. These components include, Large numbers of Electrical Isolators for Helium as well as LN2 services, Flexible Bellows and Hoses for Helium as well as LN2 services, Thermal shock tests of large numbers of 80 K Bubble shields In order to validate the helium leak tightness of these components, we have used the calibrated mass spectrometer leak detector (MSLD) at 300 K, 77 K and 4.2. Since it is very difficult to locate the leaks, which are appearing at rather lower temperatures e.g. less than 20 K, We have invented different approaches to resolve the issue of such leaks. This paper, in general describes the design of cryogenic flexible hose, assembly, couplings for leak testing, test method and techniques of thermal cycles test at 77 K inflow conditions and leak testing aspects of different cryogenic components. The test results, the problems encountered and its solutions techniques are discussed.

  8. Preliminary vibration, acoustic, and shock design and test criteria for components on the Lightweight External Tank (LWT)

    Science.gov (United States)

    1981-01-01

    The Space Shuttle LWT is divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (general Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Along with the specifications are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. A method of selecting applicable vibration, acoustic, and shock specifications is presented.

  9. Validity and variability of the 5-repetition sit-to-stand test in patients with multiple sclerosis

    DEFF Research Database (Denmark)

    Møller, Andreas Buch; Bibby, Bo Martin; Guldhammer, Anders;

    2012-01-01

    Purpose: To investigate; (i) the relationship between the 5STS-test and lower extremity muscle strength and balance, and (ii) the variability of the 5STS-test in multiple sclerosis (MS) patients. Method: 22 MS patients were divided into two groups (Group A and Group B) who completed one 5STS...... familiarization test session and two testing sessions. In Group A, session 1 also included assessment of lower extremity muscle strength. Session 2 and 3 involved completion of two 5STS-tests and assessment of balance. In Group B, session 2 and 3 involved completion of two rounds of two 5STS-tests separated......, intra-assessor test-retest variability and intra-assessor variability within test were 25.5, 22.3, and 23.1%, respectively. Inter-assessor variability within test and inter-assessor variability were 23.4 and 5.9%, respectively. Conclusions: The 5STS-test is related to lower extremity muscle strength...

  10. Design of a pulse-type strain gauge balance for a long-test-duration hypersonic shock tunnel

    Science.gov (United States)

    Wang, Y.; Liu, Y.; Jiang, Z.

    2016-11-01

    When the measurement of aerodynamic forces is conducted in a hypersonic shock tunnel, the inertial forces lead to low-frequency vibrations of the model, and its motion cannot be addressed through digital filtering because a sufficient number of cycles cannot be obtained during a tunnel run. This finding implies restrictions on the model size and mass as the natural frequencies are inversely proportional to the length scale of the model. Therefore, the force measurement still has many problems, particularly for large and heavy models. Different structures of a strain gauge balance (SGB) are proposed and designed, and the measurement element is further optimized to overcome the difficulties encountered during the measurement of aerodynamic forces in a shock tunnel. The motivation for this study is to assess the structural performance of the SGB used in a long-test-duration JF12 hypersonic shock tunnel, which has more than 100 ms of test time. Force tests were conducted for a large-scale cone with a 10^° semivertex angle and a length of 0.75 m in the JF12 long-test-duration shock tunnel. The finite element method was used for the analysis of the vibrational characteristics of the Model-Balance-Sting System (MBSS) to ensure a sufficient number of cycles, particularly for the axial force signal during a shock tunnel run. The higher-stiffness SGB used in the test shows good performance, wherein the frequency of the MBSS increases because of the stiff construction of the balance. The experimental results are compared with the data obtained in another wind tunnel and exhibit good agreement at M = 7 and α =5°.

  11. Topical antioxidants protect the skin from chemical-induced irritation in the repetitive washing test: a placebo-controlled, double-blind study.

    Science.gov (United States)

    Schempp, Christoph M; Meinke, Martina C; Lademann, Jürgen; Ferrari, Yvonne; Brecht, Thomas; Gehring, Wolfgang

    2012-10-01

    There is increasing evidence that reactive oxygen species play an important role in the development of both irritant and allergic contact dermatitis. To assess the potential of topical antioxidants to prevent the development of experimentally induced irritant contact dermatitis. We evaluated the effect of a cream containing a combination of antioxidants on sodium lauryl sulfate-induced irritant contact dermatitis in the repetitive washing test. As readout parameters for skin barrier function and cutaneous inflammation stratum corneum hydration, cutaneous blood flow and transepidermal water loss were assessed in 25 volunteers with bioengineering methods. In comparison with the cream base and a frequently used barrier cream, the antioxidant cream had high radical scavenging activity and effectively protected the skin from chemical-induced irritation. The superiority of the cream with antioxidants to the cream base suggests that reactive oxygen species, at least in part, play a role in the development of irritant contact dermatitis. © 2012 John Wiley & Sons A/S.

  12. Thermal shock tests of $beta;-sic pellets prepared from laser synthesized nanoscale sic powders

    Science.gov (United States)

    Donato, A.; Borsella, E.; Botti, S.; Martelli, S.; Nannetti, C. A.; Mancini, M. R.; Morjan, I.

    1996-10-01

    Nanoscale SiC powders, produced by laser synthesis from gaseous precursors, have been successfully used to prepare sintered pellets. All the sintered samples showed the low temperature β-SiC structures and presented an enhanced thermal conductivity (> 20%) with respect to materials prepared from commercial powders. Samples hardness and toughness, comparable with commercial products, confirmed the good samples quality. The thermal shock tests have been performed by irradiating the pellets with a Nd-YAG pulsed laser (pulse duration and energy: 0.25 μs and 0.18 J or 0.4 ms and 0.65 J). The laser fluence (power density) was increased by reducing the spot size, up to the appearance of a visible surface damage. The threshold values for the structural damage were quantified using a heat flux parameter φ abs√ tp. The measured threshold value rose from ca. 20 MW/m 2 √s for the best materials prepared from commercial SiC powders to ca. 24 MW/m 2√s for the newly developed β-SiC.

  13. Analysis on shock attenuation in gap test configuration for characterizing energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bohoon; Yoh, Jack J., E-mail: jjyoh@snu.ac.kr [Seoul National University, Seoul 151-742 (Korea, Republic of); Park, Jungsu [Agency for Defense Development, Daejeon 305-600 (Korea, Republic of)

    2016-04-14

    A pyrotechnic system consisting of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and the acceptor charges. Despite of its common use, a numerical study of such a pyrotechnic train configuration is seldom reported because proper modeling of the full process requires precise capturing of the shock wave attenuation in the gap prior to triggering a full detonation of a high explosive and accurate description of the high strain rate dynamics of the explosively loaded inert confinements. We apply a hybrid particle level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized cyclotrimethylene-trinitramine as the acceptor charge. The complex shock interaction, a critical gap thickness, an acoustic impedance, and go/no-go characteristics of the pyrotechnic system are quantitatively investigated.

  14. Vibration, acoustic, and shock design and test criteria for components on the Solid Rocket Boosters (SRB), Lightweight External Tank (LWT), and Space Shuttle Main Engines (SSME)

    Science.gov (United States)

    1984-01-01

    The vibration, acoustics, and shock design and test criteria for components and subassemblies on the space shuttle solid rocket booster (SRB), lightweight tank (LWT), and main engines (SSME) are presented. Specifications for transportation, handling, and acceptance testing are also provided.

  15. Repetitive testing of TBTO, Sea-Nine 211 and farnesol using Balanus Amphitrite (Darwin) cypris larvae: variability in larval sensitivity

    NARCIS (Netherlands)

    Willemsen, P.R.; Overbeke, J.C.; Suurmond, A.

    1998-01-01

    Settlement inhibition assays with mass cultured cypris larvae of the barnacle Balanus amphitrite are widely used in (anti)fouling research. In this study, TBTO, Sea-Nine 211 and farnesol were tested repeatedly using multiple batches of larvae to study variability in larval sensitivity. There were si

  16. Frequency and Prognostic Significance of Abnormal Liver Function Tests in Patients With Cardiogenic Shock.

    Science.gov (United States)

    Jäntti, Toni; Tarvasmäki, Tuukka; Harjola, Veli-Pekka; Parissis, John; Pulkki, Kari; Sionis, Alessandro; Silva-Cardoso, Jose; Køber, Lars; Banaszewski, Marek; Spinar, Jindrich; Fuhrmann, Valentin; Tolonen, Jukka; Carubelli, Valentina; diSomma, Salvatore; Mebazaa, Alexandre; Lassus, Johan

    2017-10-01

    Cardiogenic shock (CS) is a cardiac emergency often leading to multiple organ failure and death. Assessing organ dysfunction and appropriate risk stratification are central for the optimal management of these patients. The purpose of this study was to assess the prevalence of abnormal liver function tests (LFTs), as well as early changes of LFTs and their impact on outcome in CS. We measured LFTs in 178 patients in CS from serial blood samples taken at 0 hours, 12 hours, and 24 hours. The associations of LFT abnormalities and their early changes with all-cause 90-day mortality were estimated using Fisher's exact test and Cox proportional hazards regression analysis. Baseline alanine aminotransferase (ALT) was abnormal in 58% of the patients, more frequently in nonsurvivors. Abnormalities in other LFTs analyzed (alkaline phosphatase, gamma-glutamyl transferase, and total bilirubin) were not associated with short-term mortality. An increase in ALT of >20% within 24 hours (ΔALT>+20%) was observed in 24% of patients. ΔALT>+20% was associated with a more than 2-fold increase in mortality compared with those with stable or decreasing ALT (70% and 28%, p +20% was associated with increased 90-day mortality independent of other known risk factors. In conclusion, an increase in ALT in the initial phase was seen in 1/4 of patients in CS and was independently associated with 90-day mortality. This finding suggests that serial ALT measurements should be incorporated in the clinical assessment of patients in CS. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. [Anaphylactic shock due to recombinant human insulin: follow-up of a desensitization protocol by basophil activation test].

    Science.gov (United States)

    Luyasu, S; Hougardy, N; Hasdenteufel, F; Jacquenet, S; Weber, E; Moneret-Vautrin, A; Kanny, G

    2011-01-01

    Despite the occurrence of a severe allergic reaction including an anaphylactic shock, a drug may remain essential and impossible to replace. This may be the case of insulin in a diabetic patient. We describe the case of an anaphylactic shock to human insulin in whom a desensitization protocol was successfully achieved. A 50-year-old type 2 diabetic man presented one year after initiation of the insulin therapy an anaphylactic shock following the subcutaneous administration of a human insulin containing protamine (Insulatard®). A desensitization protocol to human insulin was performed and allowed to use two human insulin analogues containing no protamine (asparte and glargine), with a two-year event-free follow-up. Positive skin tests with insulin and protamine, and the presence of insulin specific IgE were evidenced of an IgE-mediated mechanism. Desensitization was monitored by skin tests, Maunsell's test, measurement of specific IgE and IgG4, and the basophil activation test. The decrease of basophil sensitivity to insulin is an early marker for tolerance induction. The effectiveness of the desensitization to human insulin underlines the importance to define the modalities of such desensitization protocol and of the monitoring of the tolerance induction. Copyright © 2010 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  18. Repetitive maladaptive behavior: beyond repetition compulsion.

    Science.gov (United States)

    Bowins, Brad

    2010-09-01

    Maladaptive behavior that repeats, typically known as repetition compulsion, is one of the primary reasons that people seek psychotherapy. However, even with psychotherapeutic advances it continues to be extremely difficult to treat. Despite wishes and efforts to the contrary repetition compulsion does not actually achieve mastery, as evidenced by the problem rarely resolving without therapeutic intervention, and the difficulty involved in producing treatment gains. A new framework is proposed, whereby such behavior is divided into behavior of non-traumatic origin and traumatic origin with some overlap occurring. Repetitive maladaptive behavior of non-traumatic origin arises from an evolutionary-based process whereby patterns of behavior frequently displayed by caregivers and compatible with a child's temperament are acquired and repeated. It has a familiarity and ego-syntonic aspect that strongly motivates the person to retain the behavior. Repetitive maladaptive behavior of traumatic origin is characterized by defensive dissociation of the cognitive and emotional components of trauma, making it very difficult for the person to integrate the experience. The strong resistance of repetitive maladaptive behavior to change is based on the influence of both types on personality, and also factors specific to each. Psychotherapy, although very challenging at the best of times, can achieve the mastery wished and strived for, with the aid of several suggestions provided.

  19. Heat-shock inducible polyubiquitin gene UbI undergoes alternative initiation and alternative splicing in mature chicken testes.

    Science.gov (United States)

    Mezquita, J; Pau, M; Mezquita, C

    1997-04-01

    Ubiquitin, a heat-shock protein highly expressed during spermatogenesis, plays an essential role in the differentiation of the germinal cells, particularly in the structural changes of chromatin taking place at the end of the process. To shed light on the mechanisms that modulate transcriptional activity of the heat-shock inducible polyubiquitin gene UbI during spermatogenesis and stabilize the message when transcription is not longer active, we have compared the characteristics of UbI transcripts in mature and immature testes and somatic cells. In mature chicken testes, transcription starts at a site placed closer to the heat-shock promoters than in somatic tissues. This site is upstream from the TATA box used in somatic cells. In addition, UbI transcript undergoes an alternative splicing that produces a longer 5' untranslated region in mature testis. These findings may provide a basis for the observed increase in expression of UbI in mature chicken testes and for the stability of the message when transcription ceases at the end of spermatogenesis.

  20. Preliminary vibration, acoustic, and shock design and test criteria for components on the SRB, ET, and SSME

    Science.gov (United States)

    1976-01-01

    Specifications for vibration, acoustic and shock design for components and subassemblies on the External Tank (ET), Solid Rocket Booster (SRB), and Space Shuttle Main Engine (SSME). Included are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. The space shuttle ET, SRB, and SSME have been divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (General Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Criteria for some specific components are also presented.

  1. Testing for Shock-Heated X-Ray Gas around Compact Steep Spectrum Radio Galaxies

    Science.gov (United States)

    Noel-Storr, Jacob; O'Dea, Christopher; Worrall, Diana M.; Clarke, Tracy E.; Tremblay, Grant; Baum, Stefi; Christiansen, Kevin; Mullarkey, Christopher; Mittal, Rupal

    2017-01-01

    We present Chandra and XMM-Newton X-ray, VLA radio, and optical observations of two CSS radio galaxies. B3 1445+410 is a low excitation emission line galaxy with possibly a hybrid FRI/II (or Fat Double) radio morphology. The Chandra observations are point-like and well fit with a power-law consistent with emission from a Doppler boosted core. PKS B1017-325 is a galaxy with a bent double radio morphology. The XMM-Newton observations are consistent with an ISM with a contribution from hot shocked gas. We compile selected radio and X-ray properties of the nine CSS radio galaxies with X-ray detections so far. We find that 1/3 show evidence for hot shocked gas. We note that the counts in the sources are low and the properties of the 3 sources with evidence for hot shocked gas are typical of the other CSS radio galaxies. We suggest that hot shocked gas may be typical of CSS radio galaxies due to their propagation through their host galaxies.

  2. Grammatical Change through Repetition.

    Science.gov (United States)

    Arevart, Supot

    1989-01-01

    The effect of repetition on grammatical change in an unrehearsed talk is examined based on a case study of a single learner. It was found that repetition allows for accuracy monitoring in that errors committed in repeated contexts undergo correction. Implications for teaching are discussed. (23 references) (LB)

  3. The Negative Repetition Effect

    Science.gov (United States)

    Mulligan, Neil W.; Peterson, Daniel J.

    2013-01-01

    A fundamental property of human memory is that repetition enhances memory. Peterson and Mulligan (2012) recently documented a surprising "negative repetition effect," in which participants who studied a list of cue-target pairs twice recalled fewer targets than a group who studied the pairs only once. Words within a pair rhymed, and…

  4. The acceleration of electrons at a spherical coronal shock in a streamer-like coronal field

    Science.gov (United States)

    Kong, Xiangliang; Chen, Yao; Guo, Fan

    2016-03-01

    We study the effect of large-scale coronal magnetic field on the electron acceleration at a spherical coronal shock using a test-particle method. The coronal field is approximated by an analytical solution with a streamer-like magnetic field featured by partially open magnetic field and a current sheet at the equator atop the closed region. It shows that the closed field plays the role of a trapping agency of shock-accelerated electrons, allowing for repetitive reflection and acceleration, therefore can greatly enhance the shock-electron acceleration efficiency. It is found that, with an ad hoc pitch-angle scattering, electron injected in the open field at the shock flank can be accelerated to high energies as well. In addition, if the shock is faster or stronger, a relatively harder electron energy spectrum and a larger maximum energy can be achieved.

  5. Roles of repetitive sequences

    Energy Technology Data Exchange (ETDEWEB)

    Bell, G.I.

    1991-12-31

    The DNA of higher eukaryotes contains many repetitive sequences. The study of repetitive sequences is important, not only because many have important biological function, but also because they provide information on genome organization, evolution and dynamics. In this paper, I will first discuss some generic effects that repetitive sequences will have upon genome dynamics and evolution. In particular, it will be shown that repetitive sequences foster recombination among, and turnover of, the elements of a genome. I will then consider some examples of repetitive sequences, notably minisatellite sequences and telomere sequences as examples of tandem repeats, without and with respectively known function, and Alu sequences as an example of interspersed repeats. Some other examples will also be considered in less detail.

  6. Roles of repetitive sequences

    Energy Technology Data Exchange (ETDEWEB)

    Bell, G.I.

    1991-12-31

    The DNA of higher eukaryotes contains many repetitive sequences. The study of repetitive sequences is important, not only because many have important biological function, but also because they provide information on genome organization, evolution and dynamics. In this paper, I will first discuss some generic effects that repetitive sequences will have upon genome dynamics and evolution. In particular, it will be shown that repetitive sequences foster recombination among, and turnover of, the elements of a genome. I will then consider some examples of repetitive sequences, notably minisatellite sequences and telomere sequences as examples of tandem repeats, without and with respectively known function, and Alu sequences as an example of interspersed repeats. Some other examples will also be considered in less detail.

  7. Modernisation of a test rig for determination of vehicle shock absorber characteristics by considering vehicle suspension elements and unsprung masses

    Science.gov (United States)

    Maniowski, M.; Para, S.; Knapczyk, M.

    2016-09-01

    This paper presents a modernization approach of a standard test bench for determination of damping characteristics of automotive shock absorbers. It is known that the real-life work conditions of wheel-suspension dampers are not easy to reproduce in laboratory conditions, for example considering a high frequency damper response or a noise emission. The proposed test bench consists of many elements from a real vehicle suspension. Namely, an original tyre-wheel with additional unsprung mass, a suspension spring, an elastic top mount, damper bushings and a simplified wheel guiding mechanism. Each component was tested separately in order to identify its mechanical characteristics. The measured data serve as input parameters for a numerical simulation of the test bench behaviour by using a vibratory model with 3 degrees of freedom. Study on the simulation results and the measurements are needed for further development of the proposed test bench.

  8. Wave system fitting: A new method for force measurements in shock tunnels with long test duration

    Science.gov (United States)

    Luo, Changtong; Wang, Yunpeng; Wang, Chun; Jiang, Zonglin

    2015-10-01

    Force measurements in shock tunnels are difficult due to the existence of vibrations excited by a sudden aerodynamic loading. Accelerometer inertia compensation could reduce its negative effect to some extent, but has inherent problems. A new signal decomposition method, wave system fitting (WSF), is proposed to remove vibration waves of low frequency. The WSF is accelerometer-free. It decomposes the balance signal and can separate vibration waves without the influence on the DC component, and it does work no matter the cycle of the sample signal is complete or not. As a standard signal post-processing tool in JF-12, the application results show that it works reliably with high accuracy, and it can also explain puzzling signals encountered in JF-12. WSF method is especially useful and irreplaceable whenever only a few cycles of a periodic signal could be obtained, as is usual for shock tunnels.

  9. Time-Dependent, Multifluid, Magnetohydrodynamic Shock Waves with Grain Dynamics I. Formulation and Numerical Tests

    CERN Document Server

    Ciolek, G E; Ciolek, Glenn E.; Roberge, Wayne G.

    2002-01-01

    This is the first in a series of papers on the effects of dust on the formation, propagation, and structure of nonlinear MHD waves and MHD shocks in weakly-ionized plasmas. We model the plasma as a system of 9 interacting fluids, consisting of the neutral gas, ions, electrons, and 6 grain fluids comprised of very small grains or PAHs and classical grains in different charge states. We formulate the governing equations for perpendicular shocks under approximations appropriate for dense molecular clouds, protostellar cores, and protoplanetary disks. We describe a code that obtains numerical solutions using a finite difference method, and estabish its accuracy by comparing numerical and exact solutions for special cases.

  10. Repetition and Translation Shifts

    Directory of Open Access Journals (Sweden)

    Simon Zupan

    2006-06-01

    Full Text Available Repetition manifests itself in different ways and at different levels of the text. The first basic type of repetition involves complete recurrences; in which a particular textual feature repeats in its entirety. The second type involves partial recurrences; in which the second repetition of the same textual feature includes certain modifications to the first occurrence. In the article; repetitive patterns in Edgar Allan Poe’s short story “The Fall of the House of Usher” and its Slovene translation; “Konec Usherjeve hiše”; are compared. The author examines different kinds of repetitive patterns. Repetitions are compared at both the micro- and macrostructural levels. As detailed analyses have shown; considerable microstructural translation shifts occur in certain types of repetitive patterns. Since these are not only occasional; sporadic phenomena; but are of a relatively high frequency; they reduce the translated text’s potential for achieving some of the gothic effects. The macrostructural textual property particularly affected by these shifts is the narrator’s experience as described by the narrative; which suffers a reduction in intensity.

  11. Preliminary vibration, acoustic, and shock design and test criteria for components on the HEAO-A spacecraft

    Science.gov (United States)

    1975-01-01

    These vibration, acoustic, and shock specifications provide the qualification test criteria for spacecraft components and subassemblies and for the High Energy Astronomy Observatory (HEAO-A) experiments. The HEAO-A was divided into zones and subzones to obtain simple component groupings. Zones are designated primarily to assist in determining the applicable specification. A Subzone is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, the appropriate Subzone weight ranges are available. Experiment and specific component specifications are available.

  12. Preliminary vibration, acoustic, and shock design and test criteria for components on the HEAO-C spacecraft

    Science.gov (United States)

    1975-01-01

    The vibration, acoustic, and shock specification test criteria for spacecraft components and subassemblies and for the high Energy Astronomy Observatory (HEAO-C) experiments are presented. The HEAO-C was divided into zones and subzones to obtain simple component groupings. Zones are designated primarily to assist in determining the applicable specification. A subzone (general specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, the appropriate subzone weight ranges (-A, -B, etc. ) are available. Experiment and specific component specifications are available.

  13. Soliton repetition rate in a silicon-nitride microresonator

    CERN Document Server

    Bao, Chengying; Wang, Cong; Jaramillo-Villegas, Jose A; Leaird, Daniel E; Qi, Minghao; Weiner, Andrew M

    2016-01-01

    The repetition rate of a Kerr comb comprising a single soliton in an anomalous dispersion silicon nitride microcavity is measured as a function of pump frequency tuning. The contributions from the Raman soliton self-frequency shift (SSFS) and from thermal effects are evaluated both experimentally and theoretically; the SSFS is found to dominate the changes in repetition rate. The relationship between the changes in repetition rate and pump frequency detuning is found to be independent of the nonlinearity coefficient and dispersion of the cavity. Modeling of the repetition rate change by using the generalized Lugiato-Lefever equation is discussed; the Kerr shock is found to have only a minor effect on repetition rate for cavity solitons with duration down to ~50 fs.

  14. Soliton repetition rate in a silicon-nitride microresonator.

    Science.gov (United States)

    Bao, Chengying; Xuan, Yi; Wang, Cong; Jaramillo-Villegas, Jose A; Leaird, Daniel E; Qi, Minghao; Weiner, Andrew M

    2017-02-15

    The repetition rate of a Kerr comb composed of a single soliton in an anomalous group velocity dispersion silicon-nitride microcavity is measured as a function of pump frequency. By comparing operation in the soliton and non-soliton states, the contributions from the Raman soliton self-frequency shift (SSFS) and the thermal effects are evaluated; the SSFS is found to dominate the changes in the repetition rate, similar to silica cavities. The relationship between the changes in the repetition rate and the pump frequency detuning is found to be independent of the nonlinearity coefficient and dispersion of the cavity. Modeling of the repetition rate change by using the generalized Lugiato-Lefever equation is discussed; the Kerr shock is found to have only a minor effect on repetition rate for cavity solitons with duration down to ∼50  fs.

  15. Trialogue: Preparation, Repetition and...

    Science.gov (United States)

    Oberg, Antoinette; And Others

    1996-01-01

    This paper interrogates both curriculum theory and the limits and potentials of textual forms. A set of overlapping discourses (a trialogue) focuses on inquiring into the roles of obsession and repetition in creating deeply interpretive locations for understanding. (SM)

  16. Behaviour of Ti-doped 3D carbon fibre composites under intense thermal shock tests

    Energy Technology Data Exchange (ETDEWEB)

    Centeno, A; Blanco, C; SantamarIa, R; Granda, M; Menendez, R [Instituto Nacional del Carbon (CSIC), Apdo 73, 33080 Oviedo (Spain); Pintsuk, G; Linke, J [Forschungszentrum Juelich, EURATOM Association, 52425 Juelich (Germany)], E-mail: clara@incar.csic.es

    2009-12-15

    This paper reports on the development of novel Ti-doped 3D carbon fibre composites (CFCs) and their performance when exposed to transient thermal loads (disruptions) in the electron beam facility JUDITH at different conditions. Depending on the applied load, the CFCs showed three steps of erosion: (i) breaking of PAN fibres with pull out from the surface; (ii) cracking and ablation of pitch fibres close to the interface of PAN/pitch fibre bundles; and (iii) finally, erosion of pitch fibres in the centre of the bundle. The addition of titanium carbide resulted in a significant improvement in thermal shock behaviour of these materials compared with undoped counterparts.

  17. Modelling, Testing and Analysis of a Regenerative Hydraulic Shock Absorber System

    Directory of Open Access Journals (Sweden)

    Ruichen Wang

    2016-05-01

    Full Text Available To improve vehicle fuel economy whilst enhancing road handling and ride comfort, power generating suspension systems have recently attracted increased attention in automotive engineering. This paper presents our study of a regenerative hydraulic shock absorber system which converts the oscillatory motion of a vehicle suspension into unidirectional rotary motion of a generator. Firstly a model which takes into account the influences of the dynamics of hydraulic flow, rotational motion and power regeneration is developed. Thereafter the model parameters of fluid bulk modulus, motor efficiencies, viscous friction torque, and voltage and torque constant coefficients are determined based on modelling and experimental studies of a prototype system. The model is then validated under different input excitations and load resistances, obtaining results which show good agreement between prediction and measurement. In particular, the system using piston-rod dimensions of 50–30 mm achieves recoverable power of 260 W with an efficiency of around 40% under sinusoidal excitation of 1 Hz frequency and 25 mm amplitude when the accumulator capacity is set to 0.32 L with the load resistance 20 Ω. It is then shown that the appropriate damping characteristics required from a shock absorber in a heavy-haulage vehicle can be met by using variable load resistances and accumulator capacities in a device akin to the prototype. The validated model paves the way for further system optimisation towards maximising the performance of regeneration, ride comfort and handling.

  18. A cylindrical converging shock tube for shock-interface studies.

    Science.gov (United States)

    Luo, Xisheng; Si, Ting; Yang, Jiming; Zhai, Zhigang

    2014-01-01

    A shock tube facility for generating a cylindrical converging shock wave is developed in this work. Based on the shock dynamics theory, a specific wall profile is designed for the test section of the shock tube to transfer a planar shock into a cylindrical one. The shock front in the converging part obtained from experiment presents a perfect circular shape, which proves the feasibility and reliability of the method. The time variations of the shock strength obtained from numerical simulation, experiment, and theoretical estimation show the desired converging effect in the shock tube test section. Particular emphasis is then placed on the problem of shock-interface interaction induced by cylindrical converging shock waves. For this purpose, membrane-less gas cylinder is adopted to form the interface between two different fluids while the laser sheet technique to visualize the flow field. The result shows that it is convenient to perform such experiments in this facility.

  19. 喉衬材料抗热震性能缩比考核试验方法%Subscale test method for thermal shock resistance of throat insert material

    Institute of Scientific and Technical Information of China (English)

    姜东; 李江; 魏祥庚; 陈剑

    2011-01-01

    发动机研制中需对喉衬材料抗热震性能进行考核,发展了一种用小型固体发动机模拟全尺寸发动机热载荷对喉衬材料抗热震性能进行考核的缩比试验方法.通过保证推进剂、燃烧室压强、点火升压速率和喉衬型面等参数与全尺寸发动机接近,来保证热载荷的相似,同时适当兼顾喉衬应力的状态.采用该方法较好地再现了某型发动机出现的喉衬组件断裂飞出的故障,在一定程度上验证了方法的有效性.对2种C/C材料的抗热震性能进行了对比试验,试验结果表明,2种材料的抗热震性能明显优于故障发动机使用的三向绕纱C/C材料,其中炭布-穿刺C/C材料稍优于无纬布-穿刺C/C材料.%Thermal shock resistance of throat inserts material need be checked in rocket motor design. A subscale experimental method based on simulating the thermal load of full-size rocket motors throat insert with a subscale SRM is developed to examine the thermal shock resistance performance of throat inserts material. To obtain the thermal load approach, propellant, chamber pressure, rate of ignition pressurization and the contour of the surface of throat inserts should be guaranteed to be similar with those of full-size rocket motor, at the same time, stress condition of throat inserts is taken into account. This method has well repetitiveness of the fracture failure of throat inserts of a missile, which prove the feasibility of the test to a certain extent. A comparison test for thermal shock resistance of two different composite materials was carried out. The experimental results indicate that two C/C composite materials has good thermal shock resistance than three-directional woven C/C composite material used in the failure motor, and the performance of carbon fabric pierced C/C composite material is better than that of no woven fabric pierced C/C composite material.

  20. The First Pulse of the Extremely Bright GRB 130427A: A Test Lab for Synchrotron Shocks

    Science.gov (United States)

    Preece, R.; Burgess, J. Michael; von Kienlin, A.; Bhat, P. N.; Briggs, M. S.; Byrne, D.; Chaplin, V.; Cleveland, W.; Collazzi, A. C.; Goldstein, A.; Kouveliotou, C.; Wilson-Hodge, C.; Gehrels, N.; Harding, A. K.; Nemmen, R.; Racusin, J. L.; Scargle, J. D.

    2013-01-01

    Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 s is possibly the brightest well-isolated pulse observed to date. A fine time resolution spectral analysis shows power-law decays of the peak energy from the onset of the pulse, consistent with models of internal synchrotron shock pulses. However, a strongly correlated power-law behavior is observed between the luminosity and the spectral peak energy that is inconsistent with curvature effects arising in the relativistic outflow. It is difficult for any of the existing models to account for all of the observed spectral and temporal behaviors simultaneously.

  1. 分配电箱冲击试验与数值仿真%Shock Test and Simulation of Distribution Box

    Institute of Scientific and Technical Information of China (English)

    李亚璘; 欧阳光耀

    2011-01-01

    冲击试验是舰用设备抗冲击特性研究的重要手段.对处于正常通电工作状态下的装有减振器的分配电箱进行冲击试验,采集加速度响应数据,通过处理,将其作为仿真研究的依据.利用有限元分析软件ANSYS计算分配电箱在实际冲击工况下的加速度响应,并与试验结果进行比较,分析造成两者差异的原因,总结分配电箱的抗冲击规律.%Shock test is an important method to anti-shock characteristic study of shipboard equipment. A distribution box set with vibration isolator was subjected to shock loading under electrified condition. Its acceleration response was measured and the data as the basis of simulation was processed. The acceleration response of distribution box under practical shock condition was calculated with finite element analysis software ANSYS. The simulation results were compared with shock test and the differences between both were analyzed. The anti-shock regulation of distribution box was also summarized at last. And the simulation method is proved right.

  2. When Shock Waves Collide

    CERN Document Server

    Hartigan, P; Frank, A; Hansen, E; Yirak, K; Liao, A S; Graham, P; Wilde, B; Blue, B; Martinez, D; Rosen, P; Farley, D; Paguio, R

    2016-01-01

    Supersonic outflows from objects as varied as stellar jets, massive stars and novae often exhibit multiple shock waves that overlap one another. When the intersection angle between two shock waves exceeds a critical value, the system reconfigures its geometry to create a normal shock known as a Mach stem where the shocks meet. Mach stems are important for interpreting emission-line images of shocked gas because a normal shock produces higher postshock temperatures and therefore a higher-excitation spectrum than an oblique one does. In this paper we summarize the results of a series of numerical simulations and laboratory experiments designed to quantify how Mach stems behave in supersonic plasmas that are the norm in astrophysical flows. The experiments test analytical predictions for critical angles where Mach stems should form, and quantify how Mach stems grow and decay as intersection angles between the incident shock and a surface change. While small Mach stems are destroyed by surface irregularities and ...

  3. Intelligent Shock Wave Overpressure Test System%智能化冲击波超压测试系统

    Institute of Scientific and Technical Information of China (English)

    闫宏彪; 丁永红; 王俊峰

    2015-01-01

    Impact wave overpressure test is an important parameter to measure the damage performance of weapon and ammunition. A new intelligent shock wave pressure measurement system is designed,which is composed of a detection unit,a control unit and a trigger unit. The system has the characteristics of small size,low power consump-tion,anti impact,anti electromagnetic interference,After the shock tube dynamic calibration,the free field experi-ment is applied,and it can record the key signal successfully,and the comparison between the measured data and the empirical formula is proved to be reasonable.%冲击波超压测试是衡量武器弹药毁伤性能的重要参数.设计了一种由探测单元、控制单元、触发单元构成的地面场智能化冲击波超压测试系统.该系统具有体积小、微功耗、抗冲击、抗电磁干扰等特点,通过激波管动态校准后应用于自由场实爆试验,并能成功记录关键信号,将实测数据与经验公式所得数据对比分析,证明了该系统的设计合理性.

  4. Cardiogenic shock

    Science.gov (United States)

    Shock - cardiogenic ... electrical system of the heart (heart block) Cardiogenic shock occurs when the heart is unable to pump ... orthostatic hypotension) Weak (thready) pulse To diagnose cardiogenic shock, a catheter (tube) may be placed in the ...

  5. The Shock Vibration Bulletin. Part 3. Isolation and Damping, Vibration Test Criteria, and Vibration Analysis and Test

    Science.gov (United States)

    1987-01-01

    fatigae equivalent test time of 45-mimates. 1. BACKGROUND subjected to both vibration and loose cargo testing as well an the type and amount of...Environmental Test the track laying environment. Nethods, 10 March 1975. 8. FUTURE EFFORTS 11. Soci, Darrell F., Fatigae Life Estimation Techniques, Technical

  6. Novel porcine repetitive elements

    Directory of Open Access Journals (Sweden)

    Nonneman Dan J

    2006-12-01

    Full Text Available Abstract Background Repetitive elements comprise ~45% of mammalian genomes and are increasingly known to impact genomic function by contributing to the genomic architecture, by direct regulation of gene expression and by affecting genomic size, diversity and evolution. The ubiquity and increasingly understood importance of repetitive elements contribute to the need to identify and annotate them. We set out to identify previously uncharacterized repetitive DNA in the porcine genome. Once found, we characterized the prevalence of these repeats in other mammals. Results We discovered 27 repetitive elements in 220 BACs covering 1% of the porcine genome (Comparative Vertebrate Sequencing Initiative; CVSI. These repeats varied in length from 55 to 1059 nucleotides. To estimate copy numbers, we went to an independent source of data, the BAC-end sequences (Wellcome Trust Sanger Institute, covering approximately 15% of the porcine genome. Copy numbers in BAC-ends were less than one hundred for 6 repeat elements, between 100 and 1000 for 16 and between 1,000 and 10,000 for 5. Several of the repeat elements were found in the bovine genome and we have identified two with orthologous sites, indicating that these elements were present in their common ancestor. None of the repeat elements were found in primate, rodent or dog genomes. We were unable to identify any of the replication machinery common to active transposable elements in these newly identified repeats. Conclusion The presence of both orthologous and non-orthologous sites indicates that some sites existed prior to speciation and some were generated later. The identification of low to moderate copy number repetitive DNA that is specific to artiodactyls will be critical in the assembly of livestock genomes and studies of comparative genomics.

  7. The structure of a collisionless shock in a partially ionized medium: I. Cosmic rays as test particles

    CERN Document Server

    Blasi, P; Bandiera, R; Amato, E; Caprioli, D

    2012-01-01

    A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged and neutral particles both upstream and downstream of the shock. In particular, neutrals that suffer a charge exchange downstream with shock-heated ions generate high velocity neutrals that have a finite probability of returning upstream. These neutrals might then deposit heat in the upstream plasma through ionization and charge exchange, thereby reducing the fluid Mach number. A consequence of this phenomenon, that we refer to as "the neutral return flux", is a reduction of the shock compression factor and the formation of a shock precursor upstream. The scale length of the precursor is determined by the ionization and charge exchange interaction lengths of fast neutrals moving towards upstream infinity. In the case of a shock propagating in the interstellar m...

  8. DIFFUSIVE SHOCK ACCELERATION AT COSMOLOGICAL SHOCK WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyesung [Department of Earth Sciences, Pusan National University, Pusan 609-735 (Korea, Republic of); Ryu, Dongsu, E-mail: kang@uju.es.pusan.ac.kr, E-mail: ryu@canopus.cnu.ac.kr [Department of Astronomy and Space Science, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2013-02-10

    We reexamine nonlinear diffusive shock acceleration (DSA) at cosmological shocks in the large-scale structure of the universe, incorporating wave-particle interactions that are expected to operate in collisionless shocks. Adopting simple phenomenological models for magnetic field amplification (MFA) by cosmic-ray (CR) streaming instabilities and Alfvenic drift, we perform kinetic DSA simulations for a wide range of sonic and Alfvenic Mach numbers and evaluate the CR injection fraction and acceleration efficiency. In our DSA model, the CR acceleration efficiency is determined mainly by the sonic Mach number M{sub s} , while the MFA factor depends on the Alfvenic Mach number and the degree of shock modification by CRs. We show that at strong CR modified shocks, if scattering centers drift with an effective Alfven speed in the amplified magnetic field, the CR energy spectrum is steepened and the acceleration efficiency is reduced significantly, compared to the cases without such effects. As a result, the postshock CR pressure saturates roughly at {approx}20% of the shock ram pressure for strong shocks with M{sub s} {approx}> 10. In the test-particle regime (M{sub s} {approx}< 3), it is expected that the magnetic field is not amplified and the Alfvenic drift effects are insignificant, although relevant plasma physical processes at low Mach number shocks remain largely uncertain.

  9. The special relativistic shock tube

    Science.gov (United States)

    Thompson, Kevin W.

    1986-01-01

    The shock-tube problem has served as a popular test for numerical hydrodynamics codes. The development of relativistic hydrodynamics codes has created a need for a similar test problem in relativistic hydrodynamics. The analytical solution to the special relativistic shock-tube problem is presented here. The relativistic shock-jump conditions and rarefaction solution which make up the shock tube are derived. The Newtonian limit of the calculations is given throughout.

  10. Thermal shock tests with beryllium coupons in the electron beam facility JUDITH

    Energy Technology Data Exchange (ETDEWEB)

    Roedig, M.; Duwe, R.; Schuster, J.L.A. [Forschungszentrum Juelich GmbH (Germany)] [and others

    1995-09-01

    Several grades of American and Russian beryllium have been tested in high heat flux tests by means of an electron beam facility. For safety reasons, major modifications of the facility had to be fulfilled in advance to the tests. The influence of energy densities has been investigated in the range between 1 and 7 MJ/m{sup 2}. In addition the influence of an increasing number of shots at constant energy density has been studied. For all samples, surface profiles have been measured before and after the experiments. Additional information has been gained from scanning electron microscopy, and from metallography.

  11. Development of Drop/Shock Test in Microelectronics and Impact Dynamic Analysis for Uniform Board Response

    Science.gov (United States)

    Kallolimath, Sharan Chandrashekar

    For the past several years, many researchers are constantly developing and improving board level drop test procedures and specifications to quantify the solder joint reliability performance of consumer electronics products. Predictive finite element analysis (FEA) by utilizing simulation software has become widely acceptable verification method which can reduce time and cost of the real-time test process. However, due to testing and metrological limitations it is difficult not only to simulate exact drop condition and capture critical measurement data but also tedious to calibrate the system to improve test methods. Moreover, some of the important ever changing factors such as board flexural rigidity, damping, drop height, and drop orientation results in non-uniform stress/strain distribution throughout the test board. In addition, one of the most challenging tasks is to quantify uniform stress and strain distribution throughout the test board and identify critical failure factors. The major contributions of this work are in the four aspects of the drop test in electronics as following. First of all, an analytical FEA model was developed to study the board natural frequencies and responses of the system with the consideration of dynamic stiffness, damping behavior of the material and effect of impact loading condition. An approach to find the key parameters that affect stress and strain distributions under predominate mode responses was proposed and verified with theoretical solutions. Input-G method was adopted to study board response behavior and cut boundary interpolation methods was used to analyze local model solder joint stresses with the development of global/local FEA model in ANSYS software. Second, no ring phenomenon during the drop test was identified theoretically when the test board was modeled as both discrete system and continuous system. Numerical analysis was then conducted by FEA method for detailed geometry of attached chips with solder

  12. Intradermorreação de Montenegro após sucessivas repetições do teste em Porteirinha, MG Montenegro intradermoreaction after the test sequential repetitions in Porteirinha, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Verônica Carneiro Borges

    2003-04-01

    Full Text Available Para avaliar a resposta a sucessivas aplicações da intradermorreação de Montenegro (IDRM, repetimos quatro vezes o teste em moradores de uma área endêmica de calazar que tiveram o exame negativo há 3-4 anos. Inicialmente, repetimos três IDRM nos que permaneceram negativos, com intervalo de 60 dias entre elas. Na segunda etapa, realizamos uma última reação em todos participantes do estudo. Do total de 49 indivíduos com IDRM prévia negativa, 19 (38,8% positivaram o teste em alguma das vezes, 17 (34,7% abandonaram o estudo e 13 (26,5% permaneceram com resultado negativo em todas as aplicações. Na segunda etapa, a repetição da IDRM mostrou que dos 14 que eram positivos em algum dos testes, 8 assim permaneceram e 6 tornaram-se negativos. Nossos resultados confirmam a possibilidade de indução de hipersensibilidade tardia em alguns indivíduos pela aplicação da IDRM.With the purpose of evaluating the response of sequential applications of Montenegro intradermoreaction (IDRM, we have repeated four times the test in the inhabitants of an endemic area for kala-azar, that resulted negative 3-4 years ago. Firstly, we have repeated three IDRM in those who remained negative, with a 60-day interval among them. In the second stage, we have performed a last reaction in all participants of the study. From the total of 49 individuals with prior negative IDRM, 19 (38.8% have positivated the test in some of the times, 17 (34.7% have given up the study and 13 (26.5% remained with a negative result in all the applications. In the second stage, the repetition of IDRM has shown that from the 14 positive in some of the tests, 8 remained like this and 6 have become negative. Our results confirm the possibility of late hypersensitivity induction in some individuals as a consequence of IDRM application.

  13. Design and Testing of CO2 Compression Using Supersonic Shock Wave Technology

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, Aaron [Seattle Technology Center, Bellevue, WA (United States)

    2015-06-01

    This report summarizes work performed by Ramgen and subcontractors in pursuit of the design and construction of a 10 MW supersonic CO2 compressor and supporting facility. The compressor will demonstrate application of Ramgen’s supersonic compression technology at an industrial scale using CO2 in a closed-loop. The report includes details of early feasibility studies, CFD validation and comparison to experimental data, static test experimental results, compressor and facility design and analyses, and development of aerodynamic tools. A summary of Ramgen's ISC Engine program activity is also included. This program will demonstrate the adaptation of Ramgen's supersonic compression and advanced vortex combustion technology to result in a highly efficient and cost effective alternative to traditional gas turbine engines. The build out of a 1.5 MW test facility to support the engine and associated subcomponent test program is summarized.

  14. When Shock Waves Collide

    Science.gov (United States)

    Hartigan, P.; Foster, J.; Frank, A.; Hansen, E.; Yirak, K.; Liao, A. S.; Graham, P.; Wilde, B.; Blue, B.; Martinez, D.; Rosen, P.; Farley, D.; Paguio, R.

    2016-06-01

    Supersonic outflows from objects as varied as stellar jets, massive stars, and novae often exhibit multiple shock waves that overlap one another. When the intersection angle between two shock waves exceeds a critical value, the system reconfigures its geometry to create a normal shock known as a Mach stem where the shocks meet. Mach stems are important for interpreting emission-line images of shocked gas because a normal shock produces higher postshock temperatures, and therefore a higher-excitation spectrum than does an oblique shock. In this paper, we summarize the results of a series of numerical simulations and laboratory experiments designed to quantify how Mach stems behave in supersonic plasmas that are the norm in astrophysical flows. The experiments test analytical predictions for critical angles where Mach stems should form, and quantify how Mach stems grow and decay as intersection angles between the incident shock and a surface change. While small Mach stems are destroyed by surface irregularities and subcritical angles, larger ones persist in these situations and can regrow if the intersection angle changes to become more favorable. The experimental and numerical results show that although Mach stems occur only over a limited range of intersection angles and size scales, within these ranges they are relatively robust, and hence are a viable explanation for variable bright knots observed in Hubble Space Telescope images at the intersections of some bow shocks in stellar jets.

  15. The role of short-term memory impairment in nonword repetition, real word repetition, and nonword decoding: A case study.

    Science.gov (United States)

    Peter, Beate

    2017-09-21

    In a companion study, adults with dyslexia and adults with a probable history of childhood apraxia of speech showed evidence of difficulty with processing sequential information during nonword repetition, multisyllabic real word repetition and nonword decoding. Results suggested that some errors arose in visual encoding during nonword reading, all levels of processing but especially short-term memory storage/retrieval during nonword repetition, and motor planning and programming during complex real word repetition. To further investigate the role of short-term memory, a participant with short-term memory impairment (MI) was recruited. MI was confirmed with poor performance during a sentence repetition and three nonword repetition tasks, all of which have a high short-term memory load, whereas typical performance was observed during tests of reading, spelling, and static verbal knowledge, all with low short-term memory loads. Experimental results show error-free performance during multisyllabic real word repetition but high counts of sequence errors, especially migrations and assimilations, during nonword repetition, supporting short-term memory as a locus of sequential processing deficit during nonword repetition. Results are also consistent with the hypothesis that during complex real word repetition, short-term memory is bypassed as the word is recognized and retrieved from long-term memory prior to producing the word.

  16. MIMICRY, DIFFERENCE AND REPETITION

    Directory of Open Access Journals (Sweden)

    Marcelo Mendes de Souza

    2008-07-01

    Full Text Available This article addresses Homi K. Bhabha’s concept of mimicry in a broader context, other than that of cultural studies and post-colonial studies, bringing together other concepts, such as that of Gilles Deleuze in Difference and repetition, among other texts, and other names, such as Silviano Santiago, Jorge Luís Borges, Franz Kafka and Giorgio Agamben. As a partial conclusion, the article intends to oppose Bhabha’s freudian-marxist view to Five propositions on Psychoanalysis (1973, Gilles Deleuze’s text about Psychoanalysis published right after his book The Anti-Oedipus.

  17. Thermal shock tests of {beta}-SiC pellets prepared from laser synthesized nanoscale SiC powders

    Energy Technology Data Exchange (ETDEWEB)

    Donato, A. [Assoc. EURATOM-ENEA sulla Fusione, Frascati (Italy). Centro Ricerche; Borsella, E. [Dip. Innovazione, Settore Fisica Applicata, ENEA, Centro Ricerche Frascati (Italy); Botti, S. [Dip. Innovazione, Settore Fisica Applicata, ENEA, Centro Ricerche Frascati (Italy); Martelli, S. [Dip. Innovazione, Settore Fisica Applicata, ENEA, Centro Ricerche Frascati (Italy); Nannetti, C.A. [Dip. Innovazione, Divisione Materiali Avanzati, ENEA, Centro Ricerche Casaccia, Rome (Italy); Mancini, M.R. [Dip. Innovazione, Divisione Materiali Avanzati, ENEA, Centro Ricerche Casaccia, Rome (Italy); Morjan, I. [Laser Dept. Institute of Atomic Physics, Bucharest (Romania)

    1996-10-01

    Nanoscale SiC powders, produced by laser synthesis from gaseous precursors, have been successfully used to prepare sintered pellets. All the sintered samples showed the low temperature {beta}-SiC structures and presented an enhanced thermal conductivity (>20%) with respect to materials prepared from commercial powders. Samples hardness and toughness, comparable with commercial products, confirmed the good samples quality. The thermal shock tests have been performed by irradiating the pellets with a Nd-YAG pulsed laser (pulse duration and energy: 0.25 {mu}s and 0.18 J or 0.4 ms and 0.65 J). The laser fluence (power density) was increased by reducing the spot size, up to the appearance of a visible surface damage. The threshold values for the structural damage were quantified using a heat flux parameter {phi}{sub abs}{radical}(t){sub p}. The measured threshold value rose from ca. 20 MW/m{sup 2}{radical}(s) for the best materials prepared from commercial SiC powders to ca. 24 MW/m{sup 2}{radical}(s) for the newly developed {beta}-SiC. (orig.).

  18. The Influence of Repeated Thermal Shock on the Mechanical Properties of Mongolia Scotch Pine and Moso Bamboo

    Directory of Open Access Journals (Sweden)

    Shujuan Wang

    2014-10-01

    Full Text Available The sharp temperature changes in nature (e.g., forest fires, ice, and snow can cause mechanical damage to trees and bamboo. The mechanical properties of Mongolia Scotch pine (Pinus sylvestris L. var. mongolica and Moso bamboo (Phyllostachys edulis were investigated by a three-point bending test with a repeated thermal shock process (i.e., sudden changes of temperature. The experimental results indicated that the flexural modulus, flexural strength, and deformation work per volume decreased almost linearly with the increased repetition of thermal shock treatment for both Mongolia Scotch pine and Moso bamboo. The damage caused by repeated thermal shock was stronger for Mongolia Scotch pine, as compared to Moso bamboo, under the same thermal shock treatment. Thus, the experimental results provided basic data for engineering applications of Mongolia Scotch pine and Moso bamboo after natural disturbances.

  19. Opioid/NMDA receptors blockade reverses the depressant-like behavior of foot shock stress in the mouse forced swimming test.

    Science.gov (United States)

    Haj-Mirzaian, Arya; Ostadhadi, Sattar; Kordjazy, Nastaran; Dehpour, Ahmad Reza; Ejtemaei Mehr, Shahram

    2014-07-15

    Opioid and glutamatergic receptors have a key role in depression following stress. In this study, we assessed opioid and glutamatergic receptors interaction with the depressant-like behavior of acute foot-shock stress in the mouse forced swimming test. Stress was induced by intermittent foot shock stimulation during 30min and swim periods were afterwards conducted by placing mice in separated glass cylinders filled with water for 6min. The immobility time during the last 4min of the test was considered. Acute foot-shock stress significantly increased the immobility time of mice compared to non-stressed control group (P≤0.01). Administration of non-selective opioid receptors antagonist, naltrexone (1 and 2mg/kg, i.p.), and the selective non-competitive NMDA receptor antagonist, MK-801 (0.05mg/kg, i.p.), and the selective serotonin reuptake inhibitor, fluoxetine (5mg/kg), significantly reduced the immobility time in stressed animals (P≤0.01). Lower doses of MK-801 (0.01mg/kg), naltrexone (0.3mg/kg), NMDA (75mg/kg) and morphine(5mg/kg) had no effect on foot-shock stressed mice. Combined treatment of sub-effective doses of naltrexone and MK-801 significantly showed an antidepressant-like effect (P≤0.001). On the other hand, co-administration of non-effective doses of NMDA and morphine with effective doses of naltrexone and MK-801 reversed the anti-immobility effect of these drugs. Taken together, we have for the first time demonstrated the possible role of opioid/NMDA receptors signaling in the depressant-like effect of foot-shock stress, and proposed the use of drugs that act like standard anti-depressants in stress-induced depression.

  20. Repetition in Waiting for Godot

    Institute of Scientific and Technical Information of China (English)

    李想; 魏妍

    2015-01-01

    Waiting for Godot is one of the most famous plays written by Samuel Barclay Beckett, and also is the founding work of“Theatre of the Absurd”. In the drama, repetitive phenomena shed light on the whole construction considerably. All the charac-ters were helpless and unthinking. Their dialogues were simple, nonsense and repetitive. Two scenes were cyclical. Repetition was used subtly in order to express the theme of the play, showing mental crisis after depravation of WWII.

  1. Repetition priming from moving faces.

    Science.gov (United States)

    Lander, Karen; Bruce, Vicki

    2004-06-01

    Recent experiments have suggested that seeing a familiar face move provides additional dynamic information to the viewer, useful in the recognition of identity. In four experiments, repetition priming was used to investigate whether dynamic information is intrinsic to the underlying face representations. The results suggest that a moving image primes more effectively than a static image, even when the same static image is shown in the prime and the test phases (Experiment 1). Furthermore, when moving images are presented in the test phase (Experiment 2), there is an advantage for moving prime images. The most priming advantage is found with naturally moving faces, rather than with those shown in slow motion (Experiment 3). Finally, showing the same moving sequence at prime and test produced more priming than that found when different moving sequences were shown (Experiment 4). The results suggest that dynamic information is intrinsic to the face representations and that there is an advantage to viewing the same moving sequence at prime and test.

  2. 爆炸冲击隔震系统实验研究%Tests for a damping system under blast shock

    Institute of Scientific and Technical Information of China (English)

    宜晨虹; 陈石勇; 胡八一; 汤铁钢

    2013-01-01

    实验研究了由钢丝绳隔震器组成的爆炸冲击隔震系统在爆炸冲击下的响应及破坏机理,得到了爆炸冲击隔震系统的破坏模式;通过对比实验得到隔震系统效果的定量认识;最后用快速傅里叶变换对结果进行分析.结果表明:隔震系统能够比较显著地减弱低频振动的幅值,这对于结构减振有积极的意义,可以在爆炸塔等爆炸试验场所推广应用.%The response and failure mechanism of a PGG damping system was studied with tests. According to test results, the failure pattern of the system and the quantitative cognition for the shock absorption effect of the system were found. At last, the test results were analyzed in frequency domain with FFT. The results indicated that the damping system is very effective for shock absorption in structures under blast shock.

  3. Understanding maximal repetitions in strings

    CERN Document Server

    Crochemore, Maxime

    2008-01-01

    The cornerstone of any algorithm computing all repetitions in a string of length n in O(n) time is the fact that the number of runs (or maximal repetitions) is O(n). We give a simple proof of this result. As a consequence of our approach, the stronger result concerning the linearity of the sum of exponents of all runs follows easily.

  4. [Cardiogenic shock].

    Science.gov (United States)

    Houegnifioh, Komlanvi Kafui; Gfeller, Etienne; Garcia, Wenceslao; Ribordy, Vincent

    2014-08-13

    Cardiogenic shock, especially when it complicates a myocardial infarction, is still associated with high mortality rate. Emergency department or first care physicians are often the first providers to assess the cardiogenic shock patient, and plays thereby a key role in achieving a timely diagnosis and treatment. This review will detail the actual physiopathology understanding of the cardiogenic shock, its diagnosis and management focusing on the care within the emergency department.

  5. Terminal-shock and restart control of a Mach 2.5, axisymmetric, mixed compression inlet with 40 percent internal contraction. [wind tunnel tests

    Science.gov (United States)

    Baumbick, R. J.

    1974-01-01

    Results of experimental tests conducted on a supersonic, mixed-compression, axisymmetric inlet are presented. The inlet is designed for operation at Mach 2.5 with a turbofan engine (TF-30). The inlet was coupled to either a choked orifice plate or a long duct which had a variable-area choked exit plug. Closed-loop frequency responses of selected diffuser static pressures used in the terminal-shock control system are presented. Results are shown for Mach 2.5 conditions with the inlet coupled to either the choked orifice plate or the long duct. Inlet unstart-restart traces are also presented. High-response inlet bypass doors were used to generate an internal disturbance and also to achieve terminal-shock control.

  6. Perceptual Repetition Blindness Effects

    Science.gov (United States)

    Hochhaus, Larry; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    The phenomenon of repetition blindness (RB) may reveal a new limitation on human perceptual processing. Recently, however, researchers have attributed RB to post-perceptual processes such as memory retrieval and/or reporting biases. The standard rapid serial visual presentation (RSVP) paradigm used in most RB studies is, indeed, open to such objections. Here we investigate RB using a "single-frame" paradigm introduced by Johnston and Hale (1984) in which memory demands are minimal. Subjects made only a single judgement about whether one masked target word was the same or different than a post-target probe. Confidence ratings permitted use of signal detection methods to assess sensitivity and bias effects. In the critical condition for RB a precue of the post-target word was provided prior to the target stimulus (identity precue), so that the required judgement amounted to whether the target did or did not repeat the precue word. In control treatments, the precue was either an unrelated word or a dummy.

  7. Self-controlled KR schedules: does repetition order matter?

    Science.gov (United States)

    Patterson, Jae T; Carter, Michael J; Hansen, Steve

    2013-08-01

    The impact of an experimenter-defined repetition schedule on the utility of a self-controlled KR context during motor skill acquisition was examined. Participants were required to learn three novel spatial-temporal tasks in either a random or blocked repetition schedule with or without the opportunity to control their KR. Results from the retention period showed that participants provided control over their KR schedule in a random repetition schedule demonstrated superior learning. However, performance measures from the transfer test showed that, independent of repetition schedule, learners provided the opportunity to control their KR schedule demonstrated superior transfer performance compared to their yoked counterparts. The dissociated impact of repetition schedule and self-controlled KR schedules on retention and transfer is discussed.

  8. Impaired speech repetition and left parietal lobe damage.

    Science.gov (United States)

    Fridriksson, Julius; Kjartansson, Olafur; Morgan, Paul S; Hjaltason, Haukur; Magnusdottir, Sigridur; Bonilha, Leonardo; Rorden, Christopher

    2010-08-18

    Patients with left hemisphere damage and concomitant aphasia usually have difficulty repeating others' speech. Although impaired speech repetition, the primary symptom of conduction aphasia, has been associated with involvement of the left arcuate fasciculus, its specific lesion correlate remains elusive. This research examined speech repetition among 45 stroke patients who underwent aphasia testing and MRI examination. Based on lesion-behavior mapping, the primary structural damage most closely associated with impaired speech repetition was found in the posterior portion of the left arcuate fasciculus. However, perfusion-weighted MRI revealed that tissue dysfunction, in the form of either frank damage or hypoperfusion, to the left inferior parietal lobe, rather than the underlying white matter, was associated with impaired speech repetition. This latter result suggests that integrity of the left inferior parietal lobe is important for speech repetition and, as importantly, highlights the importance of examining cerebral perfusion for the purpose of lesion-behavior mapping in acute stroke.

  9. Manually operated piston-driven shock tube

    OpenAIRE

    Reddy, KPJ; Sharath, N

    2013-01-01

    A simple hand-operated shock tube capable of producing Mach 2 shock waves is described. Performance of this miniature shock tube using compressed high pressure air created by a manually operated piston in the driver section of the shock tube as driver gas with air at 1 atm pressure as the test gas in the driven tube is presented. The performance of the shock tube is found to match well with the theoretically estimated values using normal shock relations. Applications of this shock tube named ...

  10. Collisionless ion dynamics in the shock front

    Science.gov (United States)

    Gedalin, Michael

    2016-07-01

    In the vicinity of the shock front the dynamics of ions is governed by the macroscopic regular electric and magnetic field of the shock. Upon crossing the shock the thermal ions form a non-gyrotropic distribution. The pressure of these non-gyrotropic ions shapes the downstream magnetic field. High-energy ions behave in the shock front as test particles under the influence on the macroscopic fields. The reflection and transmission coefficients of high-energy ions at an oblique shock front is not sensitive to the shock structure and depends only on the global magnetic field change at the shock.

  11. Synergy of environmental variables alters the thermal window and heat shock response: an experimental test with the crab Pachygrapsus marmoratus.

    Science.gov (United States)

    Madeira, Diana; Narciso, Luís; Diniz, Mário Sousa; Vinagre, Catarina

    2014-07-01

    The intertidal zone is an extremely variable habitat, imposing stressful conditions on its inhabiting communities. Tolerance towards extremes of temperature, salinity and pH are crucial in these habitats. Despite the vast literature on stress tolerance, few studies have focused on the synergistic effects of several variables on thermal tolerance and HSP70 (heat shock protein 70 kDa) levels. In this work, the crabs were exposed to three experimental conditions 1) thermal ramp at standard pH (8) and saline conditions (35‰) (named T), 2) thermal ramp at standard pH (8) and hyposaline conditions (15‰) (named T plus HypoS), and 3) thermal ramp at lower pH (7) and standard saline conditions (35‰) (named T plus A). Two physiological parameters (Critical Thermal Maximum - CTMax, and osmolality) and a stress biomarker (HSP70) were chosen for this analysis. These parameters were measured in all of the aforementioned conditions. CTMax for each set of conditions was reached by exposing the organisms to a rate of temperature increase of 1 °C h(-1) until loss of equilibrium. Haemolymph samples were taken every 2 °C to quantify HSP70 and osmolality. Results showed that CTMax did not differ between crabs solely exposed to T stress and crabs exposed to T plus HypoS stress. However, HSP70 production was impaired in T plus HypoS stress. When crabs were exposed to T plus A stress, they showed a significantly higher CTMax, suggesting that short-term exposure to acidified conditions may alter the thermal window of this species. Nevertheless, in T plus A conditions HSP70 production was impaired as well. Regarding osmolality it decreased according to temperature increase in all tested stress conditions. This study showed that the heat stress response is altered by the synergistic effect of variables. Physiological end-points (i.e. CTMax) may vary and the expression of stress proteins such as HSP70 may be impaired.

  12. Extrapolating the Trends of Test Drop Data with Opening Shock Factor Calculations: the Case of the Orion Main and Drogue Parachutes Inflating to 1st Reefed Stage

    Science.gov (United States)

    Potvin, Jean; Ray, Eric

    2017-01-01

    We describe a new calculation of the opening shock factor C (sub k) characterizing the inflation performance of NASA's Orion spacecraft main and drogue parachutes opening under a reefing constraint (1st stage reefing), as currently tested in the Capsule Parachute Assembly System (CPAS) program. This calculation is based on an application of the Momentum-Impulse Theorem at low mass ratio (R (sub m) is less than 10 (sup -1)) and on an earlier analysis of the opening performance of drogues decelerating point masses and inflating along horizontal trajectories. Herein we extend the reach of the Theorem to include the effects of payload drag and gravitational impulse during near-vertical motion - both important pre-requisites for CPAS parachute analysis. The result is a family of C (sub k) versus R (sub m) curves which can be used for extrapolating beyond the drop-tested envelope. The paper proves this claim in the case of the CPAS Mains and Drogues opening while trailing either a Parachute Compartment Drop Test Vehicle or a Parachute Test Vehicle (an Orion capsule boiler plate). It is seen that in all cases the values of the opening shock factor can be extrapolated over a range in mass ratio that is at least twice that of the test drop data.

  13. Reentry Shock

    Institute of Scientific and Technical Information of China (English)

    Dorine; Houston

    1998-01-01

    Dear Xiao Lan, You remember the pain of culture and reentry shock; humor me please; let mereview the facts for the sake of the students you are sending here in greater numbers.Culture shock is the emotional pain that people experience when they visit a newcountry and find customs, experiences, smells, and non-verbal communication stylesto be different from their own country.

  14. Emotional arousal enhances word repetition priming

    OpenAIRE

    Thomas, Laura A.; LaBar, Kevin S.

    2005-01-01

    Three experiments were conducted to determine if emotional content increases repetition priming magnitude. In the study phase of Experiment 1, participants rated high-arousing negative (taboo) words and neutral words for concreteness. In the test phase, they made lexical decision judgements for the studied words intermixed with novel words (half taboo, half neutral) and pseudowords. In Experiment 2, low-arousing negative (LAN) words were substituted for the taboo words, and in Experiment 3 al...

  15. The Shock and Vibration Bulletin. Part 1. Keynote Address, Invited Papers, Panel Sessions, Modal Test and Analysis.

    Science.gov (United States)

    1978-09-01

    2 DAT ColNlGJMhN T . Cannon , ...U.S. Army..Engineer..Wa..rways.. 3 Experimentl Staion VicksburgsMS...34 vehicles. J. .%p% %jo.’ .1 7 K7. INVITED PAPERS SHOCK RESPONSE RESEARCH AT THE WATERWAYS EXPERIMENT STATION Colonel John L. Cannon U.S. Army Engineer...8217 -𔄃.I,’_. ,.-.€ . 7 7 77 -1777 ’ The integral in equation (2) can be Equation (30) is now approximated to an arbitrarily high degree by a Gauss

  16. Degradation of alumina and zirconia toughened alumina (ZTA) hip prostheses tested under microseparation conditions in a shock device

    CERN Document Server

    Uribe, Juliana; Gremillard, Laurent; Reynard, Bruno

    2013-01-01

    This paper considers the degradation of alumina and zirconia toughened alumina vs. alumina for hip implants. The materials are as assumed to be load bearing surfaces subjected to shocks in wet conditions. The load is a peak of force; 9 kN was applied over 15 ms at 2 Hz for 800,000 cycles. The volumetric wear and roughness are lower for ZTA than for alumina. The long ZTA ageing did not seem to have a direct influence on the roughness. The ageing increased the wear volumes of ZTA and it was found to have a higher wear resistance compared to alumina.

  17. Experimental investigation of shock-cell noise reduction for dual-stream nozzles in simulated flight comprehensive data report. Volume 1: Test nozzles and acoustic data

    Science.gov (United States)

    Yamamoto, K.; Janardan, B. A.; Brausch, J. F.; Hoerst, D. J.; Price, A. O.

    1984-02-01

    Parameters which contribute to supersonic jet shock noise were investigated for the purpose of determining means to reduce such noise generation to acceptable levels. Six dual-stream test nozzles with varying flow passage and plug closure designs were evaluated under simulated flight conditions in an anechoic chamber. All nozzles had combined convergent-divergent or convergent flow passages. Acoustic behavior as a function of nozzle flow passage geometry was measured. The acoustic data consist primarily of 1/3 octave band sound pressure levels and overall sound pressure levels. Detailed schematics and geometric characteristics of the six scale model nozzle configurations and acoustic test point definitions are presented. Tabulation of aerodynamic test conditions and a computer listing of the measured acoustic data are displayed.

  18. Experimental investigation of shock-cell noise reduction for dual-stream nozzles in simulated flight comprehensive data report. Volume 1: Test nozzles and acoustic data

    Science.gov (United States)

    Yamamoto, K.; Janardan, B. A.; Brausch, J. F.; Hoerst, D. J.; Price, A. O.

    1984-01-01

    Parameters which contribute to supersonic jet shock noise were investigated for the purpose of determining means to reduce such noise generation to acceptable levels. Six dual-stream test nozzles with varying flow passage and plug closure designs were evaluated under simulated flight conditions in an anechoic chamber. All nozzles had combined convergent-divergent or convergent flow passages. Acoustic behavior as a function of nozzle flow passage geometry was measured. The acoustic data consist primarily of 1/3 octave band sound pressure levels and overall sound pressure levels. Detailed schematics and geometric characteristics of the six scale model nozzle configurations and acoustic test point definitions are presented. Tabulation of aerodynamic test conditions and a computer listing of the measured acoustic data are displayed.

  19. Repetition in English Political Public Speaking

    Institute of Scientific and Technical Information of China (English)

    李红梅

    2010-01-01

    Repetition is frequently used in English political public speaking to make it easy to be remembered and powerful to move the feelings of the public. This paper is intended to analyze the functions of repetition and different levels of repetition to highlight the significance of repetition in English political public speaking and the ability of using it in practice.

  20. Are gauge shocks really shocks?

    CERN Document Server

    Alcubierre, M

    2005-01-01

    The existence of gauge pathologies associated with the Bona-Masso family of generalized harmonic slicing conditions is proven for the case of simple 1+1 relativity. It is shown that these gauge pathologies are true shocks in the sense that the characteristic lines associated with the propagation of the gauge cross, which implies that the name ``gauge shock'' usually given to such pathologies is indeed correct. These gauge shocks are associated with places where the spatial hypersurfaces that determine the foliation of spacetime become non-smooth.

  1. 砂浆板冲击破坏试验研究%Damage tests for a cement mortar plate under shock load

    Institute of Scientific and Technical Information of China (English)

    顾培英; 邓昌; 章道生; 汤雷; 王建

    2015-01-01

    通过锤击、均匀冲击荷载试验,采用逐级递增循环冲击加载方式,研究冲击荷载下砂浆板的破坏特征及冲击力、冲击能与最大加速度响应间关系。试验表明,二种冲击作用均使砂浆板跨中区域出现贯穿裂缝,呈脆性劈裂破坏形态,均匀冲击作用下破坏位置与跨中有一定偏移;锤击力时程经历主冲击、次冲击、卸载三阶段,加速度响应随锤击力增加而增加,裂缝贯穿后冲击力、加速度响应大幅减小;均匀冲击下加速度有二组响应区,响应随冲击能增加而增加,当冲击能达一定程度时响应大幅减小;继续增加冲击能,响应又会增加,并较快发生劈裂破坏,响应大幅减小;支座螺栓松动能缓冲部分冲击作用。%Hammering and uniform shock tests of a cement mortar plate were conducled.The opposite sides of the plate were elastic supports.Through cyclic shocks with amplitude increasing,the failure features,the relationship between shock force and acceleration response,and the relationship between impact energy and acceleration response of the plate were studied.The results showed that a transverse crack nearby the midspan of the plate appears,its failure state is brittle splitting;the location of failure offsets the midspan under uniform shock;time history curves of the hammering force include three stages of major shock,secondary shock and unloading;the acceleration response of the plate increases with increase in the hammering force,however,the hammering force and acceleration response decrease obviously after the transverse crack appears;there are two groups of acceleration response regions under uniform shock;the acceleration response increases with increase in impact energy;once impact energy reaches a certain level,the acceleration response decreases obviously;if impact energy continuously increases,the acceleration response increases again,brittle splitting failure occurs

  2. A pneumatic driver for shock wave production

    Science.gov (United States)

    Leftwich, Megan; Mejila-Alvarez, R.; Prestridge, K.

    2011-11-01

    We are presenting a novel technique to generate shock waves in shock tube experiments. Typically this is done with a high pressure driver section that is separated from the low pressure driven section by a physical membrane. The membrane is burst at a specific pressure and a shock wave is formed. This process limits the repetition of experiments, and membrane particles must be removed from the shock tube after each experiment. The driver presented here does not contain a membrane. Instead, it uses a series of high pressure chambers and fast-acting pistons to create the pressure jump between the high pressure driver section and low pressure driven section. The entire system is controlled remotely and requires no insertion or cleanup of membranes between experiments. The system is designed to achieve shock waves exceeding Mach 3 with air as the working fluid (higher Mach numbers can be generated with other working fluids). It will allow high repetition rates, even in challenging experimental environments (such as a vertical shock tube configuration). We present results from the initial characterization of this driver system.

  3. Repetitive element hypermethylation in multiple sclerosis patients.

    Science.gov (United States)

    Neven, K Y; Piola, M; Angelici, L; Cortini, F; Fenoglio, C; Galimberti, D; Pesatori, A C; Scarpini, E; Bollati, V

    2016-06-18

    Multiple sclerosis (MS) is a complex disorder of the central nervous system whose cause is currently unknown. Evidence is increasing that DNA methylation alterations could be involved in inflammatory and neurodegenerative diseases and could contribute to MS pathogenesis. Repetitive elements Alu, LINE-1 and SAT-α, are widely known as estimators of global DNA methylation. We investigated Alu, LINE-1 and SAT-α methylation levels to evaluate their difference in a case-control setup and their role as a marker of disability. We obtained blood samples from 51 MS patients and 137 healthy volunteers matched by gender, age and smoking. Methylation was assessed using bisulfite-PCR-pyrosequencing. For all participants, medical history, physical and neurological examinations and screening laboratory tests were collected. All repetitive elements were hypermethylated in MS patients compared to healthy controls. A lower Expanded Disability Status Scale (EDSS) score was associated with a lower levels of LINE-1 methylation for 'EDSS = 1.0' and '1.5 ≤ EDSS ≤ 2.5' compared to an EDSS higher than 3, while Alu was associated with a higher level of methylation in these groups: 'EDSS = 1.0' and '1.5 ≤ EDSS ≤ 2.5'. MS patients exhibit an hypermethylation in repetitive elements compared to healthy controls. Alu and LINE-1 were associated with degree of EDSS score. Forthcoming studies focusing on epigenetics and the multifactorial pathogenetic mechanism of MS could elucidate these links further.

  4. Varianish: Jamming with Pattern Repetition

    Directory of Open Access Journals (Sweden)

    Jort Band

    2014-10-01

    Full Text Available In music, patterns and pattern repetition are often regarded as a machine-like task, indeed often delegated to drum Machines and sequencers. Nevertheless, human players add subtle differences and variations to repeated patterns that are musically interesting and often unique. Especially when looking at minimal music, pattern repetitions create hypnotic effects and the human mind blends out the actual pattern to focus on variation and tiny differences over time. Varianish is a musical instrument that aims at turning this phenomenon into a new musical experience for musician and audience: Musical pattern repetitions are found in live music and Varianish generates additional (musical output accordingly that adds substantially to the overall musical expression. Apart from the theory behind the pattern finding and matching and the conceptual design, a demonstrator implementation of Varianish is presented and evaluated.

  5. REPETITIVE CLUSTER-TILTED ALGEBRAS

    Institute of Scientific and Technical Information of China (English)

    Zhang Shunhua; Zhang Yuehui

    2012-01-01

    Let H be a finite-dimensional hereditary algebra over an algebraically closed field k and CFm be the repetitive cluster category of H with m ≥ 1.We investigate the properties of cluster tilting objects in CFm and the structure of repetitive clustertilted algebras.Moreover,we generalize Theorem 4.2 in [12](Buan A,Marsh R,Reiten I.Cluster-tilted algebra,Trans.Amer.Math.Soc.,359(1)(2007),323-332.) to the situation of CFm,and prove that the tilting graph KCFm of CFm is connected.

  6. Shock Absorbing Function Study on Denucleated Intervertebral Disc with or without Hydrogel Injection through Static and Dynamic Biomechanical Tests In Vitro

    Directory of Open Access Journals (Sweden)

    Zhiyu Zhou

    2014-01-01

    Full Text Available Hydrogel injection has been recently proposed as a novel therapy for disc degenerative diseases, with the potential to restore the spine motion and the intervertebral disc height. However, it remains unknown whether the new technique could also maintain the shock absorbing property of the treated intervertebral disc. In this study, 18 porcine lumbar bone-disc-bone specimens were collected and randomly divided into three groups: the normal with intact intervertebral discs, the mimic for the injection of disulfide cross-linked hyaluronan hydrogels following discectomy, and the control disc with discectomy only. In the static compression test, specimens in the mimic group exhibited displacements similar to those in the normal discs, whereas the control group showed a significantly larger displacement range in the first two steps (P<0.05. With the frequency increasing, all specimens generally displayed an increasing storage modulus, decreasing loss modulus, and tanδ. At any frequency point, the control group exhibited the largest value in all the three parameters among three groups while the normal group was the lowest, with the mimic group being mostly close to the normal group. Therefore, the hydrogel injection into the intervertebral discs greatly restored their shock absorbing function, suggesting that the technique could serve as an effective approach to maintaining biomechanical properties of the degenerative intervertebral disc.

  7. Repetitive elements in parasitic protozoa

    Directory of Open Access Journals (Sweden)

    Clayton Christine

    2010-05-01

    Full Text Available Abstract A recent paper published in BMC Genomics suggests that retrotransposition may be active in the human gut parasite Entamoeba histolytica. This adds to our knowledge of the various types of repetitive elements in parasitic protists and the potential influence of such elements on pathogenicity. See research article http://www.biomedcentral.com/1471-2164/11/321

  8. [Neurogenic shock].

    Science.gov (United States)

    Meister, Rafael; Pasquier, Mathieu; Clerc, David; Carron, Pierre-Nicolas

    2014-08-13

    The neurogenic shock is a common complication of spinal cord injury, especially when localized at the cervical level. Characterized by a vasoplegia (hypotension) and bradycardia, the neurogenic shock is secondary to the damage of the sympathetic nervous system. The clinical presentation often includes tetraplegia, with or without respiratory failure. Early treatment aims to minimize the occurrence of secondary spinal cord lesions resulting from systemic ischemic injuries. Medical management consists in a standardized ABCDE approach, in order to stabilize vital functions and immobilize the spine. The hospital care includes performing imaging, further measures of neuro-resuscitation, and coordinated surgical assessment and treatment of any other injury.

  9. 传爆药冲击波感度试验方法的简化研究%Simplified Shock Wave Sensitivity Test Method of Booster Explosives

    Institute of Scientific and Technical Information of China (English)

    严家佳; 王建灵; 张哲; 李鸿宾; 杨斐

    2015-01-01

    A new type of small scale gap test method ( SSGT) , in which RDX was substitutedby A-IX-I [ m( RDX)︰m(insensitive agent) =95︰5]as donor casts, wasintroduced to study thesensitivity of shock wave. The explosion energy output performance of donor explosives was tested by a group of none gap tests. Result shows that the average mass of donor explosives is 1 195. 5 mg, and the relatively error is 0. 495%;the average pitting depth of identification slab is 1. 769mm, and relatively error is 0. 96%. It indicates that donor explosive has a good performance. This method was used to study the shock wave sensitivity of JH-14 before or after aging testsathigh temperatures. It shows that the aged explosives tend to have higher shock wave sensitivity, and the sensitivity increases with the increase of age time of accepters.%尝试了一种用压装A-IX-I(RDX与钝感剂质量比为95︰5)药柱替代纯RDX作为施主药柱进行冲击波感度试验( SSGT)的方法,通过零隔板试验,检验了施主药柱的爆炸能量输出性能。所得施主药柱的平均质量为1195.5 mg,相对误差0.495%;鉴定块的平均凹痕深度1.769 mm,相对误差0.96%,说明压装法得到的施主药柱性能较好。利用该方法研究了JH-14传爆药经过高温加速老化前后的冲击波感度,结果显示,老化后的样品冲击波感度具有增加的趋势。

  10. Nonthermal radiation from relativistic electrons accelerated at spherically expanding shocks

    CERN Document Server

    Kang, Hyesung

    2014-01-01

    We study the evolution of the energy spectrum of cosmic-ray electrons accelerated at spherically expanding shocks with low Mach numbers and the ensuing spectral signatures imprinted in radio synchrotron emission. Time-dependent simulations of diffusive shock acceleration (DSA) of electrons in the test-particle limit have been performed for spherical shocks with the parameters relevant for typical shocks in the intracluster medium. The electron and radiation spectra at the shock location can be described properly by the test-particle DSA predictions with the instantaneous shock parameters. However, the volume integrated spectra of both electrons and radiation deviate significantly from the test-particle power-laws, because the shock compression ratio and the flux of injected electrons at the shock gradually decrease as the shock slows down in time. So one needs to be cautious about interpreting observed radio spectra of evolving shocks by simple DSA models in the test-particle regime.

  11. Repetition suppression and repetition priming are processing outcomes.

    Science.gov (United States)

    Wig, Gagan S

    2012-01-01

    Abstract There is considerable evidence that repetition suppression (RS) is a cortical signature of previous exposure to the environment. In many instances RS in specific brain regions is accompanied by improvements in specific behavioral measures; both observations are outcomes of repeated processing. In understanding the mechanism by which brain changes give rise to behavioral changes, it is important to consider what aspect of the environment a given brain area or set of areas processes, and how this might be expressed behaviorally.

  12. Cohesive Function of Lexical Repetition in Text

    Institute of Scientific and Technical Information of China (English)

    张莉; 卢沛沛

    2013-01-01

    Lexical repetition is the most direct form of lexical cohesion,which is the central device for making texts hang together. Although repetition is the most direct way to emphasize,it performs the cohesive effect more apparently.

  13. Diffusive Acceleration of Ions at Interplanetary Shocks

    CERN Document Server

    Baring, M G; Baring, Matthew G.; Summerlin, Errol J.

    2005-01-01

    Heliospheric shocks are excellent systems for testing theories of particle acceleration in their environs. These generally fall into two classes: (1) interplanetary shocks that are linear in their ion acceleration characteristics, with the non-thermal ions serving as test particles, and (2) non-linear systems such as the Earth's bow shock and the solar wind termination shock, where the accelerated ions strongly influence the magnetohydrodynamic structure of the shock. This paper explores the modelling of diffusive acceleration at a particular interplanetary shock, with an emphasis on explaining in situ measurements of ion distribution functions. The observational data for this event was acquired on day 292 of 1991 by the Ulysses mission. The modeling is performed using a well-known kinetic Monte Carlo simulation, which has yielded good agreement with observations at several heliospheric shocks, as have other theoretical techniques, namely hybrid plasma simulations, and numerical solution of the diffusion-conv...

  14. PCR amplification of repetitive sequences as a possible approach in relative species quantification

    DEFF Research Database (Denmark)

    Ballin, Nicolai Zederkopff; Vogensen, Finn Kvist; Karlsson, Anders H

    2012-01-01

    in binary mixtures. PCR LUX primers were designed that amplify repetitive and single copy sequences to establish the species dependent number (constants) (SDC) of amplified repetitive sequences per genome. The SDCs and data from amplification of repetitive sequences were tested for their applicability...... to relatively quantify the amount of chicken DNA in a binary mixture of chicken DNA and pig DNA. However, the designed PCR primers lack the specificity required for regulatory species control....

  15. Culture Shock

    Institute of Scientific and Technical Information of China (English)

    宋文玲

    2004-01-01

    Specialists say that it is not easy to get used to life in a new culture.“Culture shock”is the term these specialists use when talking about the feelings that people have in a new environment.There are three stages of culture shock,say the specialists.In the first stage,the newcomers like their new environment,Then when the fresh experience

  16. Shock Waves

    CERN Document Server

    Jiang, Z

    2005-01-01

    The International Symposium on Shock Waves (ISSW) is a well established series of conferences held every two years in a different location. A unique feature of the ISSW is the emphasis on bridging the gap between physicists and engineers working in fields as different as gas dynamics, fluid mechanics and materials sciences. The main results presented at these meetings constitute valuable proceedings that offer anyone working in this field an authoritative and comprehensive source of reference.

  17. Measurement of impulse peak insertion loss from two acoustic test fixtures and four hearing protector conditions with an acoustic shock tube

    Directory of Open Access Journals (Sweden)

    William J Murphy

    2015-01-01

    Full Text Available Impulse peak insertion loss (IPIL was studied with two acoustic test fixtures and four hearing protector conditions at the E-A-RCAL Laboratory. IPIL is the difference between the maximum estimated pressure for the open-ear condition and the maximum pressure measured when a hearing protector is placed on an acoustic test fixture (ATF. Two models of an ATF manufactured by the French-German Research Institute of Saint-Louis (ISL were evaluated with high-level acoustic impulses created by an acoustic shock tube at levels of 134 decibels (dB, 150 dB, and 168 dB. The fixtures were identical except that the E-A-RCAL ISL fixture had ear canals that were 3 mm longer than the National Institute for Occupational Safety and Health (NIOSH ISL fixture. Four hearing protection conditions were tested: Combat Arms earplug with the valve open, ETYPlugs ® earplug, TacticalPro headset, and a dual-protector ETYPlugs earplug with TacticalPro earmuff. The IPILs measured for the E-A-RCAL fixture were 1.4 dB greater than the National Institute for Occupational Safety and Health (NIOSH ISL ATF. For the E-A-RCAL ISL ATF, the left ear IPIL was 2.0 dB greater than the right ear IPIL. For the NIOSH ATF, the right ear IPIL was 0.3 dB greater than the left ear IPIL.

  18. Measurement of impulse peak insertion loss from two acoustic test fixtures and four hearing protector conditions with an acoustic shock tube.

    Science.gov (United States)

    Murphy, William J; Fackler, Cameron J; Berger, Elliott H; Shaw, Peter B; Stergar, Mike

    2015-01-01

    Impulse peak insertion loss (IPIL) was studied with two acoustic test fixtures and four hearing protector conditions at the E-A-RCAL Laboratory. IPIL is the difference between the maximum estimated pressure for the open-ear condition and the maximum pressure measured when a hearing protector is placed on an acoustic test fixture (ATF). Two models of an ATF manufactured by the French-German Research Institute of Saint-Louis (ISL) were evaluated with high-level acoustic impulses created by an acoustic shock tube at levels of 134 decibels (dB), 150 dB, and 168 dB. The fixtures were identical except that the E-A-RCAL ISL fixture had ear canals that were 3 mm longer than the National Institute for Occupational Safety and Health (NIOSH) ISL fixture. Four hearing protection conditions were tested: Combat Arms earplug with the valve open, ETYPlugs ® earplug, TacticalPro headset, and a dual-protector ETYPlugs earplug with TacticalPro earmuff. The IPILs measured for the E-A-RCAL fixture were 1.4 dB greater than the National Institute for Occupational Safety and Health (NIOSH) ISL ATF. For the E-A-RCAL ISL ATF, the left ear IPIL was 2.0 dB greater than the right ear IPIL. For the NIOSH ATF, the right ear IPIL was 0.3 dB greater than the left ear IPIL.

  19. The golden ratio of gait harmony: repetitive proportions of repetitive gait phases.

    Science.gov (United States)

    Iosa, Marco; Fusco, Augusto; Marchetti, Fabio; Morone, Giovanni; Caltagirone, Carlo; Paolucci, Stefano; Peppe, Antonella

    2013-01-01

    In nature, many physical and biological systems have structures showing harmonic properties. Some of them were found related to the irrational number φ known as the golden ratio that has important symmetric and harmonic properties. In this study, the spatiotemporal gait parameters of 25 healthy subjects were analyzed using a stereophotogrammetric system with 25 retroreflective markers located on their skin. The proportions of gait phases were compared with φ, the value of which is about 1.6180. The ratio between the entire gait cycle and stance phase resulted in 1.620 ± 0.058, that between stance and the swing phase was 1.629 ± 0.173, and that between swing and the double support phase was 1.684 ± 0.357. All these ratios did not differ significantly from each other (F = 0.870, P = 0.422, repeated measure analysis of variance) or from φ (P = 0.670, 0.820, 0.422, resp., t-tests). The repetitive gait phases of physiological walking were found in turn in repetitive proportions with each other, revealing an intrinsic harmonic structure. Harmony could be the key for facilitating the control of repetitive walking. Harmony is a powerful unifying factor between seemingly disparate fields of nature, including human gait.

  20. The Golden Ratio of Gait Harmony: Repetitive Proportions of Repetitive Gait Phases

    Directory of Open Access Journals (Sweden)

    Marco Iosa

    2013-01-01

    Full Text Available In nature, many physical and biological systems have structures showing harmonic properties. Some of them were found related to the irrational number known as the golden ratio that has important symmetric and harmonic properties. In this study, the spatiotemporal gait parameters of 25 healthy subjects were analyzed using a stereophotogrammetric system with 25 retroreflective markers located on their skin. The proportions of gait phases were compared with , the value of which is about 1.6180. The ratio between the entire gait cycle and stance phase resulted in 1.620 ± 0.058, that between stance and the swing phase was 1.629 ± 0.173, and that between swing and the double support phase was 1.684 ± 0.357. All these ratios did not differ significantly from each other (, , repeated measure analysis of variance or from (, resp., t-tests. The repetitive gait phases of physiological walking were found in turn in repetitive proportions with each other, revealing an intrinsic harmonic structure. Harmony could be the key for facilitating the control of repetitive walking. Harmony is a powerful unifying factor between seemingly disparate fields of nature, including human gait.

  1. Object color affects identification and repetition priming.

    Science.gov (United States)

    Uttl, Bob; Graf, Peter; Santacruz, Pilar

    2006-10-01

    We investigated the influence of color on the identification of both non-studied and studied objects. Participants studied black and white and color photos of common objects and memory was assessed with an identification test. Consistent with our meta-analysis of prior research, we found that objects were easier to identify from color than from black and white photos. We also found substantial priming in all conditions, and study-to-test changes in an object's color reduced the magnitude of priming. Color-specific priming effects were large for color-complex objects, but minimal for color-simple objects. The pattern and magnitude of priming effects was not influenced either by the extent to which an object always appears in the same color (i.e., whether a color is symptomatic of an object) or by the object's origin (natural versus fabricated). We discuss the implications of our findings for theoretical accounts of object perception and repetition priming.

  2. Place field repetition and spatial learning in a multicompartment environment.

    Science.gov (United States)

    Grieves, Roddy M; Jenkins, Bryan W; Harland, Bruce C; Wood, Emma R; Dudchenko, Paul A

    2016-01-01

    Recent studies have shown that place cells in the hippocampus possess firing fields that repeat in physically similar, parallel environments. These results imply that it should be difficult for animals to distinguish parallel environments at a behavioral level. To test this, we trained rats on a novel odor-location task in an environment with four parallel compartments which had previously been shown to yield place field repetition. A second group of animals was trained on the same task, but with the compartments arranged in different directions, an arrangement we hypothesised would yield less place field repetition. Learning of the odor-location task in the parallel compartments was significantly impaired relative to learning in the radially arranged compartments. Fewer animals acquired the full discrimination in the parallel compartments compared to those trained in the radial compartments, and the former also required many more sessions to reach criterion compared to the latter. To confirm that the arrangement of compartments yielded differences in place cell repetition, in a separate group of animals we recorded from CA1 place cells in both environments. We found that CA1 place cells exhibited repeated fields across four parallel local compartments, but did not do so when the same compartments were arranged radially. To confirm that the differences in place field repetition across the parallel and radial compartments depended on their angular arrangement, and not incidental differences in access to an extra-maze visual landmark, we repeated the recordings in a second set of rats in the absence of the orientation landmark. We found, once again, that place fields showed repetition in parallel compartments, and did not do so in radially arranged compartments. Thus place field repetition, or lack thereof, in these compartments was not dependent on extra-maze cues. Together, these results imply that place field repetition constrains spatial learning.

  3. Results of molten salt panel and component experiments for solar central receivers: Cold fill, freeze/thaw, thermal cycling and shock, and instrumentation tests

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, J.E.; Ralph, M.E.; Chavez, J.M.; Dunkin, S.R.; Rush, E.E.; Ghanbari, C.M.; Matthews, M.W.

    1995-01-01

    Experiments have been conducted with a molten salt loop at Sandia National Laboratories in Albuquerque, NM to resolve issues associated with the operation of the 10MW{sub e} Solar Two Central Receiver Power Plant located near Barstow, CA. The salt loop contained two receiver panels, components such as flanges and a check valve, vortex shedding and ultrasonic flow meters, and an impedance pressure transducer. Tests were conducted on procedures for filling and thawing a panel, and assessing components and instrumentation in a molten salt environment. Four categories of experiments were conducted: (1) cold filling procedures, (2) freeze/thaw procedures, (3) component tests, and (4) instrumentation tests. Cold-panel and -piping fill experiments are described, in which the panels and piping were preheated to temperatures below the salt freezing point prior to initiating flow, to determine the feasibility of cold filling the receiver and piping. The transient thermal response was measured, and heat transfer coefficients and transient stresses were calculated from the data. Freeze/thaw experiments were conducted with the panels, in which the salt was intentionally allowed to freeze in the receiver tubes, then thawed with heliostat beams. Slow thermal cycling tests were conducted to measure both how well various designs of flanges (e.g., tapered flanges or clamp type flanges) hold a seal under thermal conditions typical of nightly shut down, and the practicality of using these flanges on high maintenance components. In addition, the flanges were thermally shocked to simulate cold starting the system. Instrumentation such as vortex shedding and ultrasonic flow meters were tested alongside each other, and compared with flow measurements from calibration tanks in the flow loop.

  4. [Definition of shock types].

    Science.gov (United States)

    Adams, H A; Baumann, G; Gänsslen, A; Janssens, U; Knoefel, W; Koch, T; Marx, G; Müller-Werdan, U; Pape, H C; Prange, W; Roesner, D; Standl, T; Teske, W; Werner, G; Zander, R

    2001-11-01

    Definitions of shock types. Hypovolaemic shock is a state of insufficient perfusion of vital organs with consecutive imbalance of oxygen supply and demand due to an intravascular volume deficiency with critically impaired cardiac preload. Subtypes are haemorrhagic shock, hypovolaemic shock in the narrow sense, traumatic-haemorrhagic shock and traumatic-hypovolaemic shock. Cardiac shock is caused by a primary critical cardiac pump failure with consecutive inadequate oxygen supply of the organism. Anaphylactic shock is an acute failure of blood volume distribution (distributive shock) and caused by IgE-dependent, type-I-allergic, classical hypersensibility, or a physically, chemically, or osmotically induced IgE-independent anaphylactoid hypersensibility. The septic shock is a sepsis-induced distribution failure of the circulating blood volume in the sense of a distributive shock. The neurogenic shock is a distributive shock induced by generalized and extensive vasodilatation with consecutive hypovolaemia due to an imbalance of sympathetic and parasympathetic regulation of vascular smooth muscles.

  5. The Shock and Vibration Bulletin: Proceedings on the Symposium on ShocK and Vibration (52nd) Held in New Orleans, Louisiana on 26-28 October 1981. Part 3. Environmental Testing and Simulation, Flight Environments.

    Science.gov (United States)

    1982-05-01

    showed that the statistical reement in terms of resonant frequencies measures of whole-body vibration from in the region of 2.5 to 30 Hz. ambulation to...to identify the ward end (guidance section) of the missile. The highest failure mode. shock levels mesured at the guidance section were B52 captive

  6. Variação da força muscular em testes repetitivos de 1-RM em crianças pré-púberes Variación de la fuerza en tests repetitivos de 1-RM en pre-púberes Variation of the muscular strength in repetitive 1-RM test in prepubescent children

    Directory of Open Access Journals (Sweden)

    André Luiz Demantova Gurjão

    2005-12-01

    sometidos a ocho sesiones de pruebas de 1-RM en los ejercicios de extensión de piernas en máquina y curl con barra en pie, con el intervalo de 48 horas entre cada sesión. Tres esfuerzos, intervalados durante 3-5 minutos de descanso, fueron ejecutados por los chicos en cada uno de los ejercicios escogidos. Se observaron aumentos significantes de 30,2% y 22,7% entre la primera y la octava sesión de pruebas en los ejercicios de la extensión de piernas en máquina y curl con barra en pie, respectivamente (P 0,05. Esos resultados indican que el número necesario de sesiones para la estabilización de la fuerza muscular en las pruebas de 1-RM parece ser dependiente de la tarea de cada tipo ejecutado y, posiblemente, del tamaño del agrupamiento de los agonistas musculares involucraron en la ejecución de la tarea del motivo. Por consiguiente, lo que resulta nos hace pensar en que para una evaluación más necesaria de la fuerza muscular de los muchachos pré-puberes, a través de las pruebas de 1-RM, son necesarias de tres a cinco sesiones del familiarization.Although one-repetition maximum tests (1-RM are widely employed to evaluate the muscular power, the lack of previous familiarization with the test procedures may cause erroneous interpretations. Thus, the purpose of this study was to analyze the behavior of the muscular strength in prepubescent children during 1-RM repetitive tests. For this, nine boys (9.5 ± 0.5 years; 35.1 ± 6.9 kg; 138.3 ± 6.1 cm with no previous experience in weight exerciseswere submitted to eight sessions of 1-RM tests in the leg extension and arm curl exercises, and with a 48 hours interval between sessions. Three trials with 3-5 minutes of resting interval were performed by subjects in each of the chosen exercises. It was observed significant increases of 30.2% and 22.7% between the first and eighth session in the leg extension and arm curl exercise tests, respectively (P < 0.05. However, no statistically significant difference was found

  7. Heat-shock protein 70: molecular supertool?

    Science.gov (United States)

    Aufricht, Christoph

    2005-06-01

    The cellular stress response decreases cellular injury, either via primary induction of cytoresistance or by secondary enhancement of cellular repair mechanisms. The most frequently studied and best understood effectors of the cellular stress response are the heat shock proteins (HSP). HSP are among the oldest tools in the cellular protein machinery, demonstrating extremely high conservation of the genetic code since bacteria. Molecular chaperons, with the HSP-70 being the prototype, cooperate in transport and folding of proteins, preventing aggregation, and even resolubilizing injured proteins. Increasing evidence supports a role for HSP during the recovery from renal ischemia, in particular in cellular salvage from apoptotic cell death and cytoskeletal restoration. Recent studies also report the potential for biomolecular profiling of newborns for the risk of acute renal failure. In peritoneal dialysis novel data suggest the use of HSP expression for biocompatibility testing. More importantly, HSP are prime therapeutic candidates for clinical situations associated with predictable insults, such as organ procurement in transplant medicine and repetitive exposure to hyperosmolar and acidotic peritoneal dialysis fluids. The next challenge will be to define the regulatory pathways of the cellular stress response in these models to introduce novel therapeutic interventions, such as new pharmaceutics enhancing the HSP expression.

  8. Circuit considerations for repetitive railguns

    Energy Technology Data Exchange (ETDEWEB)

    Honih, E.M.

    1986-01-01

    Railgun electromagnetic launchers have significant military and scientific potential. They provide direct conversion of electrical energy to projectile kinetic energy, and they offer the hope of achieving projectile velocities greatly exceeding the limits of conventional guns. With over 10 km/sec already demonstrated, railguns are attracting attention for tactical and strategic weapons systems and for scientific equation-of-state research. The full utilization of railguns will require significant improvements in every aspect of system design - projectile, barrel, and power source - to achieve operation on a large scale. This paper will review fundamental aspects of railguns, with emphasis on circuit considerations and repetitive operation.

  9. Do Stimulus-Action Associations Contribute to Repetition Priming?

    Science.gov (United States)

    Dennis, Ian; Perfect, Timothy J.

    2013-01-01

    Despite evidence that response learning makes a major contribution to repetition priming, the involvement of response representations at the level of motor actions remains uncertain. Levels of response representation were investigated in 4 experiments that used different tasks at priming and test. Priming for stimuli that required congruent…

  10. Do Stimulus-Action Associations Contribute to Repetition Priming?

    Science.gov (United States)

    Dennis, Ian; Perfect, Timothy J.

    2013-01-01

    Despite evidence that response learning makes a major contribution to repetition priming, the involvement of response representations at the level of motor actions remains uncertain. Levels of response representation were investigated in 4 experiments that used different tasks at priming and test. Priming for stimuli that required congruent…

  11. Characterization of shocked beryllium

    Directory of Open Access Journals (Sweden)

    Papin P.A.

    2012-08-01

    Full Text Available While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. In the current work, high strain rate tests were conducted using both explosive drive and a gas gun to accelerate the material. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. Two constitutive strength (plasticity models, the Preston-Tonks-Wallace (PTW and Mechanical Threshold Stress (MTS models, were calibrated using common quasi-static and Hopkinson bar data. However, simulations with the two models give noticeably different results when compared with the measured experimental wave profiles. The experimental results indicate that, even if fractured by the initial shock loading, the Be remains sufficiently intact to support a shear stress following partial release and subsequent shock re-loading. Additional “arrested” drive shots were designed and tested to minimize the reflected tensile pulse in the sample. These tests were done to both validate the model and to put large shock induced compressive loads into the beryllium sample.

  12. Localized shocks

    CERN Document Server

    Roberts, Daniel A; Susskind, Leonard

    2014-01-01

    We study products of precursors of spatially local operators, $W_{x_{n}}(t_{n}) ... W_{x_1}(t_1)$, where $W_x(t) = e^{-iHt} W_x e^{iHt}$. Using chaotic spin-chain numerics and gauge/gravity duality, we show that a single precursor fills a spatial region that grows linearly in $t$. In a lattice system, products of such operators can be represented using tensor networks. In gauge/gravity duality, they are related to Einstein-Rosen bridges supported by localized shock waves. We find a geometrical correspondence between these two descriptions, generalizing earlier work in the spatially homogeneous case.

  13. Generation and evolution of interplanetary slow shocks

    Directory of Open Access Journals (Sweden)

    C.-C. Wu

    Full Text Available It is well known that most MHD shocks observed within 1 AU are MHD fast shocks. Only a very limited number of MHD slow shocks are observed within 1 AU. In order to understand why there are only a few MHD slow shocks observed within 1 AU, we use a one-dimensional, time-dependent MHD code with an adaptive grid to study the generation and evolution of interplanetary slow shocks (ISS in the solar wind. Results show that a negative, nearly square-wave perturbation will generate a pair of slow shocks (a forward and a reverse slow shock. In addition, the forward and the reverse slow shocks can pass through each other without destroying their characteristics, but the propagating speeds for both shocks are decreased. A positive, square-wave perturbation will generate both slow and fast shocks. When a forward slow shock (FSS propagates behind a forward fast shock (FFS, the former experiences a decreasing Mach number. In addition, the FSS always disappears within a distance of 150R (where R is one solar radius from the Sun when there is a forward fast shock (with Mach number ≥1.7 propagating in front of the FSS. In all tests that we have performed, we have not discovered that the FSS (or reverse slow shock evolves into a FFS (or reverse fast shock. Thus, we do not confirm the FSS-FFS evolution as suggested by Whang (1987.

  14. Investigation of shock focusing in a cavity with incident shock diffracted by an obstacle

    Science.gov (United States)

    Zhang, Q.; Chen, X.; He, L.-M.; Rong, K.; Deiterding, R.

    2017-03-01

    Experiments and numerical simulations were carried out in order to investigate the focusing of a shock wave in a test section after the incident shock has been diffracted by an obstacle. A conventional shock tube was used to generate the planar shock. Incident shock Mach numbers of 1.4 and 2.1 were tested. A high-speed camera was employed to obtain schlieren photos of the flow field in the experiments. In the numerical simulations, a weighted essentially non-oscillatory (WENO) scheme of third-order accuracy supplemented with structured dynamic mesh adaptation was adopted to simulate the shock wave interaction. Good agreement between experiments and numerical results is observed. The configurations exhibit shock reflection phenomena, shock-vortex interaction and—in particular—shock focusing. The pressure history in the cavity apex was recorded and compared with the numerical results. A quantitative analysis of the numerically observed shock reflection configurations is also performed by employing a pseudo-steady shock transition boundary calculation technique. Regular reflection, single Mach reflection and transitional Mach reflection phenomena are observed and are found to correlate well with analytic predictions from shock reflection theory.

  15. Studies of the uncanny: the repetition factor

    Directory of Open Access Journals (Sweden)

    Julia Teitelroit Martins

    2011-06-01

    Full Text Available Freud’s essay The Uncanny (Das Unheimliche offers many indications for the comprehension of an aesthetics of the uncanny which deserve to be explored. Nonetheless, a concept traverses it from beginning to end: the return – which enables its reading under the light of Beyond the pleasure principle, written along the same span of time. Emphasis is given to the uncanny in the sense of repetition of the different – a paradox in terms, like the strangely familiar uncanny. In order to test the validity of an aesthetic reading under this perspective, follows an analysis of the brief short story “A terceira margem do rio” (“The third margin of the river”, by Guimarães Rosa.

  16. Digital repetitive control under varying frequency conditions

    OpenAIRE

    Ramos Fuentes, Germán Andrés

    2012-01-01

    The tracking/rejection of periodic signals constitutes a wide field of research in the control theory and applications area and Repetitive Control has proven to be an efficient way to face this topic; however, in some applications the period of the signal to be tracked/rejected changes in time or is uncertain, which causes and important performance degradation in the standard repetitive controller. This thesis presents some contributions to the open topic of repetitive control workin...

  17. Movement repetitions in physical and occupational therapy during spinal cord injury rehabilitation.

    Science.gov (United States)

    Zbogar, D; Eng, J J; Miller, W C; Krassioukov, A V; Verrier, M C

    2017-02-01

    Longitudinal observational study. To quantify the amount of upper- and lower-extremity movement repetitions (that is, voluntary movements as part of a functional task or specific motion) occurring during inpatient spinal cord injury (SCI), physical (PT) and occupational therapy (OT), and examine changes over the inpatient rehabilitation stay. Two stand-alone inpatient SCI rehabilitation centers. Participants: A total of 103 patients were recruited through consecutive admissions to SCI rehabilitation. Trained assistants observed therapy sessions and obtained clinical outcome measures in the second week following admission and in the second to last week before discharge. PT and OT time, upper- and lower-extremity repetitions and changes in these outcomes over the course of rehabilitation stay. We observed 561 PT and 347 OT sessions. Therapeutic time comprised two-thirds of total therapy time. Summed over PT and OT, the median upper-extremity repetitions in patients with paraplegia were 7 repetitions and in patients with tetraplegia, 42 repetitions. Lower-extremity repetitions and steps primarily occurred in ambulatory patients and amounted to 218 and 115, respectively (summed over PT and OT sessions at discharge). Wilcoxon-signed rank tests revealed that most repetition variables did not change significantly over the inpatient rehabilitation stay. In contrast, clinical outcomes for the arm and leg improved over this time period. Repetitions of upper- and lower-extremity movements are markedly low during PT and OT sessions. Despite improvements in clinical outcomes, there was no significant increase in movement repetitions over the course of inpatient rehabilitation stay.

  18. [Repetition and fear of dying].

    Science.gov (United States)

    Lerner, B D

    1995-03-01

    In this paper a revision is made of the qualifications of Repetition (R) in Freuds work, i.e. its being at the service of the Pleasure Principle and, beyond it, the binding of free energy due to trauma. Freud intends to explain with this last concept the "fort-da" and the traumatic dreams (obsessively reiterated self-reproaches may be added to them). The main thesis of this work is that R. is not only a defense against the recollection of the ominous past (as in the metaphorical deaths of abandonment and desertion) but also a way of maintaining life and identify fighting against the inescapable omninous future (known but yet experienced), i.e. our own death. Some forms of R. like habits, identificatory behaviors and sometimes even magic, are geared to serve the life instinct. A literary illustration shows this desperate fight.

  19. Pressure rig for repetitive casting

    Science.gov (United States)

    Vasquez, Peter (Inventor); Hutto, William R. (Inventor); Philips, Albert R. (Inventor)

    1989-01-01

    The invention is a pressure rig for repetitive casting of metal. The pressure rig performs like a piston for feeding molten metal into a mold. Pressure is applied to an expandable rubber diaphragm which expands like a balloon to force the metal into the mold. A ceramic cavity which holds molten metal is lined with blanket-type insulating material, necessitating only a relining for subsequent use and eliminating the lengthy cavity preparation inherent in previous rigs. In addition, the expandable rubber diaphragm is protected by the insulating material thereby decreasing its vulnerability to heat damage. As a result of the improved design the life expectancy of the pressure rig contemplated by the present invention is more than doubled. Moreover, the improved heat protection has allowed the casting of brass and other alloys with higher melting temperatures than possible in the conventional pressure rigs.

  20. Simulation and test for hydraulic electromagnetic energy-regenerative shock absorber%液电式馈能减振器外特性仿真与试验

    Institute of Scientific and Technical Information of China (English)

    张晗; 过学迅; 徐琳; 张杰

    2014-01-01

    With the rising concerns of global environmental issues, energy saving in automobiles becomes an important subject. In order to achieve the purpose of vibration reduction, the traditional passive shock absorber converts the vehicle vibration energy to thermal energy, and then the thermal energy is released into the air. However, the energy-regenerative shock absorber could harvest this part of the energy. This paper presents a vehicular hydraulic electromagnetic energy-regenerative shock absorber (HESA) which is designed for acquiring the vibration energy caused by road irregularity. It is composed of a hydraulic cylinder, two check valves, two accumulators, a hydraulic motor, a generator, and hydraulic lines. When the vehicle is subjected to vertical vibration, the oil in the HESA flows to the hydraulic motor through a hydraulic line, then the rotating hydraulic motor drives a generator to produce electricity. In order to consider the vibration reduction performance of the HESA, the damping characteristic was analyzed in detail. Through theoretical analysis, the damping force mathematical model of the HESA was deduced, and the calculation program was written in MATLAB, based on the HESA damping force mathematical model. The indicator diagram characteristic and speed characteristic of the HESA under the working condition of a sinusoidal displacement input of 1.67Hz was obtained from simulation tests, which was designed according to a national absorber test procedure. A test bench was constructed to verify the results of a simulation. The comparison between the bench test data and simulation data showed that the value of a compression travel damping force was smaller than the rebound travel’s, and the peak value of the simulation data was identical with the value in test data. The simulation speed characteristic curve of the HESA was compared with the bench test data. However, there were some distortions in the test indicator diagram characteristic curve because

  1. Memory, emotion, and pupil diameter: Repetition of natural scenes.

    Science.gov (United States)

    Bradley, Margaret M; Lang, Peter J

    2015-09-01

    Recent studies have suggested that pupil diameter, like the "old-new" ERP, may be a measure of memory. Because the amplitude of the old-new ERP is enhanced for items encoded in the context of repetitions that are distributed (spaced), compared to massed (contiguous), we investigated whether pupil diameter is similarly sensitive to repetition. Emotional and neutral pictures of natural scenes were viewed once or repeated with massed (contiguous) or distributed (spaced) repetition during incidental free viewing and then tested on an explicit recognition test. Although an old-new difference in pupil diameter was found during successful recognition, pupil diameter was not enhanced for distributed, compared to massed, repetitions during either recognition or initial free viewing. Moreover, whereas a significant old-new difference was found for erotic scenes that had been seen only once during encoding, this difference was absent when erotic scenes were repeated. Taken together, the data suggest that pupil diameter is not a straightforward index of prior occurrence for natural scenes. © 2015 Society for Psychophysiological Research.

  2. The influence of incident shock Mach number on radial incident shock wave focusing

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2016-04-01

    Full Text Available Experiments and numerical simulations were carried out to investigate radial incident shock focusing on a test section where the planar incident shock wave was divided into two identical ones. A conventional shock tube was used to generate the planar shock. Incident shock Mach number of 1.51, 1.84 and 2.18 were tested. CCD camera was used to obtain the schlieren photos of the flow field. Third-order, three step strong-stability-preserving (SSP Runge-Kutta method, third-order weighed essential non-oscillation (WENO scheme and adaptive mesh refinement (AMR algorithm were adopted to simulate the complicated flow fields characterized by shock wave interaction. Good agreement between experimental and numerical results was observed. Complex shock wave configurations and interactions (such as shock reflection, shock-vortex interaction and shock focusing were observed in both the experiments and numerical results. Some new features were observed and discussed. The differences of structure of flow field and the variation trends of pressure were compared and analyzed under the condition of different Mach numbers while shock wave focusing.

  3. Collisionless electrostatic shocks

    DEFF Research Database (Denmark)

    Andersen, H.K.; Andersen, S.A.; Jensen, Vagn Orla

    1970-01-01

    An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth......An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth...

  4. 长试验时间爆轰驱动激波风洞技术研究%INVESTIGATING INTO TECHNIQUES FOR EXTENDING THE TEST-DURATION OF DETONATION-DRIVEN SHOCK TUNNELS

    Institute of Scientific and Technical Information of China (English)

    姜宗林; 李进平; 赵伟; 刘云峰; 俞鸿儒

    2012-01-01

    地面试验是先进高超声速飞行器研制的主要手段之一,获得满足高超声速气动实验研究的长时间高焓气流是发展激波风洞技术的关键难题之一.依据反向爆轰驱动方法,针对满足超燃试验有效时问的要求,讨论了爆轰驱动激波风洞运行缝合条件匹配、喷管起动激波干扰控制和激波管末端激波边界层相互作用等因素对激波风洞试验时间的制约及其相应的解决方法.应用这些延长试验时间的激波风洞创新技术,成功研制了基于反向爆轰驱动方法的超大型激波风洞,试验时间长达100ms,并有复现高超声速飞行条件的流动模拟能力.%Ground test is the important and indispensable method for the research and development of hypersonic vehicle, and the acquisition of the high-enthalpy test flow with long enough test time in the test is one of the key challenges for the shock tunnel. Based on detonation-driven shock tunnel, several factors that are of significant influences on the test time are discussed and the corresponding solutions for extending test time are proposed in this paper, including the tailored condition, the shock starting process in the nozzle and the interaction of reflected shock and boundary layer, aiming to meet the requirement for the test time of supersonic combustion experiments. Through the application of the proposed methods, a large detonation-driven shock tunnel has been successfully developed, which can provide the test time of more than 100 microseconds and are capable of duplicating the hypersonic flight conditions.

  5. Comparing repetition-based melody segmentation models

    NARCIS (Netherlands)

    Rodríguez López, M.E.; de Haas, Bas; Volk, Anja

    2014-01-01

    This paper reports on a comparative study of computational melody segmentation models based on repetition detection. For the comparison we implemented five repetition-based segmentation models, and subsequently evaluated their capacity to automatically find melodic phrase boundaries in a corpus of 2

  6. Task Repetition and Second Language Speech Processing

    Science.gov (United States)

    Lambert, Craig; Kormos, Judit; Minn, Danny

    2017-01-01

    This study examines the relationship between the repetition of oral monologue tasks and immediate gains in L2 fluency. It considers the effect of aural-oral task repetition on speech rate, frequency of clause-final and midclause filled pauses, and overt self-repairs across different task types and proficiency levels and relates these findings to…

  7. Repetitions: A Cross-Cultural Study.

    Science.gov (United States)

    Murata, Kumiko

    1995-01-01

    This study investigated how repetition is used in conversation among native speakers of British English, native speakers of Japanese, and Japanese speakers of English. Five interactional functions of repetition (interruption-orientated, solidarity, silence-avoidance, hesitation, and reformulation) were identified, as well as the cultural factors…

  8. Digital repetitive control under varying frequency conditions

    CERN Document Server

    Ramos, Germán A; Olm, Josep M

    2013-01-01

    The tracking/rejection of periodic signals constitutes a wide field of research in the control theory and applications area. Repetitive Control has proven to be an efficient way to face this topic. However, in some applications the frequency of the reference/disturbance signal is time-varying or uncertain. This causes an important performance degradation in the standard Repetitive Control scheme. This book presents some solutions to apply Repetitive Control in varying frequency conditions without loosing steady-state performance. It also includes a complete theoretical development and experimental results in two representative systems. The presented solutions are organized in two complementary branches: varying sampling period Repetitive Control and High Order Repetitive Control. The first approach allows dealing with large range frequency variations while the second allows dealing with small range frequency variations. The book also presents applications of the described techniques to a Roto-magnet plant and...

  9. Shock Analysis of Sentinel-3 SLSTR Parabolic Mirror Assembly

    Science.gov (United States)

    Braun, Benjamin; Kiel, Daniel

    2014-06-01

    This paper presents the different steps that have been undertaken to demonstrate the successful shock qualification of the Parabolic Mirror Assembly (PMA) in the frame of the Sentinel-3 SLSTR development. The unit has failed the first qualification shock test in terms of shift of natural frequencies and optical alignment. The objectives of the subsequent analyses are:- to correlate the finite element model with the PMA shock test on unit level,- to determine the interface loads between different parts of the PMA assembly for the PMA shock test on unit level,- to assess the PMA interface loads induced by the instrument level shock test,- to derive a reduced shock input spectrum for the PMA shock test on unit level with respect to a second qualification test.

  10. Strategies for Using Repetition as a Powerful Teaching Tool

    Science.gov (United States)

    Saville, Kirt

    2011-01-01

    Brain research indicates that repetition is of vital importance in the learning process. Repetition is an especially useful tool in the area of music education. The success of repetition can be enhanced by accurate and timely feedback. From "simple repetition" to "repetition with the addition or subtraction of degrees of freedom," there are many…

  11. Strategies for Using Repetition as a Powerful Teaching Tool

    Science.gov (United States)

    Saville, Kirt

    2011-01-01

    Brain research indicates that repetition is of vital importance in the learning process. Repetition is an especially useful tool in the area of music education. The success of repetition can be enhanced by accurate and timely feedback. From "simple repetition" to "repetition with the addition or subtraction of degrees of freedom," there are many…

  12. Geometrical shock dynamics for magnetohydrodynamic fast shocks

    KAUST Repository

    Mostert, W.

    2016-12-12

    We describe a formulation of two-dimensional geometrical shock dynamics (GSD) suitable for ideal magnetohydrodynamic (MHD) fast shocks under magnetic fields of general strength and orientation. The resulting area–Mach-number–shock-angle relation is then incorporated into a numerical method using pseudospectral differentiation. The MHD-GSD model is verified by comparison with results from nonlinear finite-volume solution of the complete ideal MHD equations applied to a shock implosion flow in the presence of an oblique and spatially varying magnetic field ahead of the shock. Results from application of the MHD-GSD equations to the stability of fast MHD shocks in two dimensions are presented. It is shown that the time to formation of triple points for both perturbed MHD and gas-dynamic shocks increases as (Formula presented.), where (Formula presented.) is a measure of the initial Mach-number perturbation. Symmetry breaking in the MHD case is demonstrated. In cylindrical converging geometry, in the presence of an azimuthal field produced by a line current, the MHD shock behaves in the mean as in Pullin et al. (Phys. Fluids, vol. 26, 2014, 097103), but suffers a greater relative pressure fluctuation along the shock than the gas-dynamic shock. © 2016 Cambridge University Press

  13. Testing the External Shock Model of Gamma-Ray Bursts using the Late-Time Simultaneous Optical and X-ray Afterglows

    CERN Document Server

    Urata, Yuji; Sakamoto, Takanori; Huang, Kuiyun; Zheng, Weikang; Sato, Goro; Aoki, Tsutomu; Deng, Jinsong; Ioka, Kunihito; Ip, WingHuen; Kawabata, Koji S; Lee, YiHsi; Liping, Xin; Mito, Hiroyuki; Miyata, Takashi; Nakada, Yoshikazu; Ohsugi, Takashi; Qiu, Yulei; Soyano, Takao; Tarusawa, Kenichi; Tashiro, Makoto; Uemura, Makoto; Wei, Jianyan; Yamashita, Takuya

    2007-01-01

    We study the ``normal'' decay phase of the X-ray afterglows of gamma-ray bursts (GRBs), which follows the shallow decay phase, using the events simultaneously observed in the R-band. The classical external shock model, in which neither the delayed energy injection nor time-dependency of shock micro-physics is considered, shows that the decay indices of the X-ray and R-band light curves, $\\alpha_{\\rm X}$ and $\\alpha_{\\rm O}$, obey a certain relation, and that in particular, $\\alpha_{\\rm O}-\\alpha_{\\rm X}$ should be larger than -1/4. For our selected 14 samples, we have found that 7 events violate the limit taking into account 1$\\sigma$ error, so that a fraction of events are outliers of the classical external shock model at the ``normal'' decay phase.

  14. Repetition suppression and expectation suppression are dissociable in time in early auditory evoked fields.

    Science.gov (United States)

    Todorovic, Ana; de Lange, Floris P

    2012-09-26

    Repetition of a stimulus, as well as valid expectation that a stimulus will occur, both attenuate the neural response to it. These effects, repetition suppression and expectation suppression, are typically confounded in paradigms in which the nonrepeated stimulus is also relatively rare (e.g., in oddball blocks of mismatch negativity paradigms, or in repetition suppression paradigms with multiple repetitions before an alternation). However, recent hierarchical models of sensory processing inspire the hypothesis that the two might be separable in time, with repetition suppression occurring earlier, as a consequence of local transition probabilities, and suppression by expectation occurring later, as a consequence of learnt statistical regularities. Here we test this hypothesis in an auditory experiment by orthogonally manipulating stimulus repetition and stimulus expectation and, using magnetoencephalography, measuring the neural response over time in human subjects. We found that stimulus repetition (but not stimulus expectation) attenuates the early auditory response (40-60 ms), while stimulus expectation (but not stimulus repetition) attenuates the subsequent, intermediate stage of auditory processing (100-200 ms). These findings are well in line with hierarchical predictive coding models, which posit sequential stages of prediction error resolution, contingent on the level at which the hypothesis is generated.

  15. Precision markedly attenuates repetitive lift capacity.

    Science.gov (United States)

    Collier, Brooke R; Holland, Laura; McGhee, Deirdre; Sampson, John A; Bell, Alison; Stapley, Paul J; Groeller, Herbert

    2014-01-01

    This study investigated the effect of precision on time to task failure in a repetitive whole-body manual handling task. Twelve participants were required to repetitively lift a box weighing 65% of their single repetition maximum to shoulder height using either precise or unconstrained box placement. Muscle activity, forces exerted at the ground, 2D body kinematics, box acceleration and psychophysical measures of performance were recorded until task failure was reached. With precision, time to task failure for repetitive lifting was reduced by 72%, whereas the duration taken to complete a single lift and anterior deltoid muscle activation increased by 39% and 25%, respectively. Yet, no significant difference was observed in ratings of perceived exertion or heart rate at task failure. In conclusion, our results suggest that when accuracy is a characteristic of a repetitive manual handling task, physical work capacity will decline markedly. The capacity to lift repetitively to shoulder height was reduced by 72% when increased accuracy was required to place a box upon a shelf. Lifting strategy and muscle activity were also modified, confirming practitioners should take into consideration movement precision when evaluating the demands of repetitive manual handling tasks.

  16. 毁伤威力场冲击波无线分布式测试方法研究∗%Study on Damage Power Field Shock Wave Measuring Method Based on Wireless Distributed Test Technology

    Institute of Scientific and Technical Information of China (English)

    杨帆; 梁永烨; 杜红棉; 尤文斌; 崔敏; 王玉全; 刘帆; 焦耀晗

    2015-01-01

    The shock wave overpressure test is an important tool to evaluate the destructive power of weapons or ex-plosives for damage power field. It plays a significant role in the field of military and defense. In view of the advan-tages and disadvantages between the traditional method of lead and the storage method, this paper analyzes the signal characteristics of the shock wave and nations mark test requirements,and put forward a kind of combination of wireless sensor network( WSN) technology and FPGA logic control technology of the shock wave wireless distributed test method. The system is dynamic calibrated by shock tube and multiple range live-fire test. The results show that the system has a simple layout,trigger strategy is flexible,wireless synchronization trigger performance good and the high accuracy of the data rate,especially suitable for apply to mutilate power field under complicated conditions in multipoint shock wave testing tasks.%毁伤威力场中冲击波超压测试是评估武器或炸药毁伤威力的一个重要手段,在军工国防领域具有重要作用。针对传统引线法与存储法这两种测试方法的优缺点,分析了冲击波的信号特点及国军标的相关测试要求,提出一种结合无线传感网络( WSN)技术和FPGA逻辑控制技术的冲击波无线分布式测试方法。系统经过激波管动态校准及多次靶场实弹试验,验证了系统具有布设简单、触发策略灵活、无线同步触发性能良好及数据准确度高等优点,特别适合适用于毁伤威力场中复杂恶劣环境下多测点冲击波测试任务。

  17. Radiative Shock Waves In Emerging Shocks

    Science.gov (United States)

    Drake, R. Paul; Doss, F.; Visco, A.

    2011-05-01

    In laboratory experiments we produce radiative shock waves having dense, thin shells. These shocks are similar to shocks emerging from optically thick environments in astrophysics in that they are strongly radiative with optically thick shocked layers and optically thin or intermediate downstream layers through which radiation readily escapes. Examples include shocks breaking out of a Type II supernova (SN) and the radiative reverse shock during the early phases of the SN remnant produced by a red supergiant star. We produce these shocks by driving a low-Z plasma piston (Be) at > 100 km/s into Xe gas at 1.1 atm. pressure. The shocked Xe collapses to > 20 times its initial density. Measurements of structure by radiography and temperature by several methods confirm that the shock wave is strongly radiative. We observe small-scale perturbations in the post-shock layer, modulating the shock and material interfaces. We describe a variation of the Vishniac instability theory of decelerating shocks and an analysis of associated scaling relations to account for the growth of these perturbations, identify how they scale to astrophysical systems such as SN 1993J, and consider possible future experiments. Collaborators in this work have included H.F. Robey, J.P. Hughes, C.C. Kuranz, C.M. Huntington, S.H. Glenzer, T. Doeppner, D.H. Froula, M.J. Grosskopf, and D.C. Marion ________________________________ * Supported by the US DOE NNSA under the Predictive Sci. Academic Alliance Program by grant DE-FC52-08NA28616, the Stewardship Sci. Academic Alliances program by grant DE-FG52-04NA00064, and the Nat. Laser User Facility by grant DE-FG03-00SF22021.

  18. Physical Characteristics Underpinning Repetitive Lunging in Fencing.

    Science.gov (United States)

    Turner, Anthony N; Marshall, Geoff; Phillips, James; Noto, Angelo; Buttigieg, Conor; Chavda, Shyam; Downing, William; Atlay, Nathan; Dimitriou, Lygeri; Kilduff, Laim

    2016-11-01

    Turner, AN, Marshall, G, Phillips, J, Noto, A, Buttigieg, C, Chavda, S, Downing, W, Atlay, N, Dimitriou, L, and Kilduff, L. Physical characteristics underpinning repetitive lunging in fencing. J Strength Cond Res 30(11): 3134-3139, 2016-Given the repetitive demand to execute lunging and changes in direction within fencing, the ability to sustain these at maximal capacity is fundamental to performance. The aim of this study was threefold. First, to provide normative values for this variable referred to as repeat lunge ability (RLA) and second to identify the physical characteristics that underpin it. Third, was to establish if a cause and effect relationship existed by training the associated characteristics. Assessment of lower-body power, reactive strength, speed, change of direction speed (CODS), and a sport-specific RLA were conducted on senior and junior elite male fencers (n = 36). Fencers were on average (±SD) 18.9 ± 3.2 years of age, 174.35 ± 10.42 cm tall, 70.67 ± 7.35 kg in mass, and 8.5 ± 4.2 years fencing experience. The RLA test had average work times of 16.03 ± 1.40 seconds and demonstrated "large" to "very large" associations with all tested variables, but in particular CODS (r = 0.70) and standing broad jump (SBJ; r = -0.68). Through linear regression analysis, these also provided a 2-predictor model accounting for 61% of the common variance associated with RLA. A cause and effect relationship with SBJ and CODS was confirmed by the training group, where RLA performance in these fencers improved from 15.80 ± 1.07 to 14.90 ± 0.86 seconds, with the magnitude of change reported as "moderate" (effect size (ES) = 0.93). Concurrent improvements were also noted in both SBJ (216.86 ± 17.15 vs. 221.71 ± 17.59 cm) and CODS (4.44 ± 0.29 vs. 4.31 ± 0.09 seconds) and while differences were only significant in SBJ, magnitudes of change were classed as "small" (ES = 0.28) and "moderate" (ES = 0.61), respectively. In conclusion, to improve RLA strength

  19. Characterization of Shocked Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Cady, Carl M [Los Alamos National Laboratory; Adams, Chris D [Los Alamos National Laboratory; Hull, Lawrence M [Los Alamos National Laboratory; Gray III, George T [Los Alamos National Laboratory; Prime, Michael B [Los Alamos National Laboratory; Addessio, Francis L [Los Alamos National Laboratory; Wynn, Thomas A [Los Alamos National Laboratory; Brown, Eric N [Los Alamos National Laboratory

    2012-08-24

    Beryllium metal has many excellent structural properties in addition to its unique radiation characteristics, including: high elastic modulus, low Poisson's ratio, low density, and high melting point. However, it suffers from several major mechanical drawbacks: 1) high anisotropy - due to its hexagonal lattice structure and its susceptibility to crystallographic texturing; 2) susceptibility to impurity-induced fracture - due to grain boundary segregation; and 3) low intrinsic ductility at ambient temperatures thereby limiting fabricability. While large ductility results from deformation under the conditions of compression, the material can exhibit a brittle behavior under tension. Furthermore, there is a brittle to ductile transition at approximately 200 C under tensile conditions. While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. The beryllium used in this study was Grade S200-F (Brush Wellman, Inc., Elmore, OH) material. The work focused on high strain rate deformation and examine the validity of constitutive models in deformation rate regimes, including shock, the experiments were modeled using a Lagrangian hydrocode. Two constitutive strength (plasticity) models, the Preston-Tonks-Wallace (PTW) and Mechanical Threshold Stress (MTS) models, were calibrated using the same set of quasi-static and Hopkinson bar data taken at temperatures from 77K to 873K and strain rates from 0.001/sec to 4300/sec. In spite of being calibrated on the same data, the two models give noticeably different results when compared with the measured wave profiles. These high strain rate tests were conducted using both explosive drive and a gas gun to

  20. Investigating repetition and change in musical rhythm by functional MRI.

    Science.gov (United States)

    Danielsen, A; Otnæss, M K; Jensen, J; Williams, S C R; Ostberg, B C

    2014-09-05

    Groove-based rhythm is a basic and much appreciated feature of Western popular music. It is commonly associated with dance, movement and pleasure and is characterized by the repetition of a basic rhythmic pattern. At various points in the musical course, drum breaks occur, representing a change compared to the repeated pattern of the groove. In the present experiment, we investigated the brain response to such drum breaks in a repetitive groove. Participants were scanned with functional magnetic resonance imaging (fMRI) while listening to a previously unheard naturalistic groove with drum breaks at uneven intervals. The rhythmic pattern and the timing of its different parts as performed were the only aspects that changed from the repetitive sections to the breaks. Differences in blood oxygen level-dependent activation were analyzed. In contrast to the repetitive parts, the drum breaks activated the left cerebellum, the right inferior frontal gyrus (RIFG), and the superior temporal gyri (STG) bilaterally. A tapping test using the same stimulus showed an increase in the standard deviation of inter-tap-intervals in the breaks versus the repetitive parts, indicating extra challenges for auditory-motor integration in the drum breaks. Both the RIFG and STG have been associated with structural irregularity and increase in musical-syntactical complexity in several earlier studies, whereas the left cerebellum is known to play a part in timing. Together these areas may be recruited in the breaks due to a prediction error process whereby the internal model is being updated. This concurs with previous research suggesting a network for predictive feed-forward control that comprises the cerebellum and the cortical areas that were activated in the breaks.

  1. Viscous Shear Layers Formed by Non-Bifurcating Shock Waves in Shock-Tubes

    Science.gov (United States)

    Grogan, Kevin; Ihme, Matthias

    2015-11-01

    Shock-tubes are test apparatuses that are used extensively for chemical kinetic measurements. Under ideal conditions, shock-tubes provide a quiescent region behind a reflected shock wave where combustion may take place without complications arising from gas-dynamic effects. However, due to the reflected shock wave encountering a boundary layer, significant inhomogeneity may be introduced into the test region. The bifurcation of the reflected shock-wave is well-known to occur under certain conditions; however, a viscous shear layer may form behind a non-bifurcating reflected shock wave as well and may affect chemical kinetics and ignition of certain fuels. The focus of this talk is on the development of the viscous shear layer and the coupling to the ignition in the regime corresponding to the negative temperature conditions.

  2. Geometrical on-the-fly shock detection in SPH

    CERN Document Server

    Beck, Alexander M; Donnert, Julius M F

    2015-01-01

    We present an on-the-fly geometrical approach for shock detection and Mach number calculation in simulations employing smoothed particle hydrodynamics (SPH). We utilize pressure gradients to select shock candidates and define up- and downstream positions. We obtain hydrodynamical states in the up- and downstream regimes with a series of normal and inverted kernel weightings parallel and perpendicular to the shock normals. Our on-the-fly geometrical Mach detector incorporates well within the SPH formalism and has low computational cost. We implement our Mach detector into the simulation code GADGET and alongside many SPH improvements. We test our shock finder in a sequence of shock-tube tests with successively increasing Mach numbers exceeding by far the typical values inside galaxy clusters. For the all shocks, we resolve the shocks well and the correct Mach numbers are assigned. An application to a strong magnetized shock-tube gives stable results in full magnetohydrodynamic set-ups. We simulate a merger of ...

  3. Advanced and Exploratory Shock Sensing Mechanisms.

    Energy Technology Data Exchange (ETDEWEB)

    Nelsen, Nicholas; Kolb, James; Kulkarni, Akshay; Sorscher, Zachary; Habing, Clayton; Mathis, Allen; Beller, Zachary

    2017-09-01

    Mechanical component response to shock environments must be predictable in order to ensure reliability and safety. Whether the shock input results from accidental drops during transportation to projectile impact scenarios, the system must irreversibly transition into a safe state that is incapable of triggering the component . With this critical need in mind, the 2017 Nuclear Weapons Summer Product Realization Institute (NW SPRINT) program objective sought the design of a passive shock failsafe with emphasis on additively manufactured (AM) components. Team Advanced and Exploratory (A&E) responded to the challenge by designing and delivering multiple passive shock sensing mech anisms that activate within a prescribed mechanical shock threshold. These AM failsafe designs were tuned and validated using analytical and computational techniques including the shock response spectrum (SRS) and finite element analysis (FEA). After rapid prototyping, the devices experienced physical shock tests conducted on Sandia drop tables to experimentally verify performance. Keywords: Additive manufacturing, dynamic system, failsafe, finite element analysis, mechanical shock, NW SPRINT, shock respon se spectrum

  4. Concept mediation in trilingual translation: evidence from response time and repetition priming patterns.

    Science.gov (United States)

    Francis, Wendy S; Gallard, Sabrina L K

    2005-12-01

    Translation responses to individual words were elicited from 48 English-Spanish-French trilinguals, who translated in six directions at study and two directions at test. Patterns of translation response times and error rates at study reflected the relative proficiency of the trilinguals in comprehension and production of their three languages. At test, repeated items were translated more quickly than new items, with the strongest priming effects occurring for identical repetitions. Repetition priming was also substantial when only the stimulus language or only the response language matched from study to test, implying that repeated comprehension and production processes contribute to priming in translation. Patterns of response times and repetition priming indicate that translation in all directions involved conceptual access. Additive patterns in response time asymmetries and repetition priming were consistent with the treatment of word comprehension and production processes of translation as independent.

  5. Repetitive Bibliographical Information in Relational Databases.

    Science.gov (United States)

    Brooks, Terrence A.

    1988-01-01

    Proposes a solution to the problem of loading repetitive bibliographic information in a microcomputer-based relational database management system. The alternative design described is based on a representational redundancy design and normalization theory. (12 references) (Author/CLB)

  6. Computer-Related Repetitive Stress Injuries

    Science.gov (United States)

    ... on the shoulder Epicondylitis: elbow soreness often called "tennis elbow" Ganglion cyst: swelling or lump in the wrist ... Bones, Muscles, and Joints Carpal Tunnel Syndrome Medial Epicondylitis Repetitive Stress Injuries Contact Us Print Resources Send ...

  7. Digital repetitive control under varying frequency conditions

    OpenAIRE

    Ramos Fuentes, Germán Andrés

    2012-01-01

    Premi extraordinari doctorat curs 2011-2012, àmbit d’Enginyeria Industrial The tracking/rejection of periodic signals constitutes a wide field of research in the control theory and applications area and Repetitive Control has proven to be an efficient way to face this topic; however, in some applications the period of the signal to be tracked/rejected changes in time or is uncertain, which causes and important performance degradation in the standard repetitive controller. This the...

  8. SI Engine with repetitive NS spark plug

    Science.gov (United States)

    Pancheshniy, Sergey; Nikipelov, Andrey; Anokhin, Eugeny; Starikovskiy, Andrey; Laplase Team; Mipt Team; Pu Team

    2013-09-01

    Now de-facto the only technology for fuel-air mixtures ignition in IC engines exists. It is a spark discharge of millisecond duration in a short discharge gap. The reason for such a small variety of methods of ignition initiation is very specific conditions of the engine operation. First, it is very high-pressure of fuel-air mixture - from 5-7 atmospheres in old-type engines and up to 40-50 atmospheres on the operating mode of HCCI. Second, it is a very wide range of variation of the oxidizer/fuel ratio in the mixture - from almost stoichiometric (0.8-0.9) at full load to very lean (φ = 0.3-0.5) mixtures at idle and/or economical cruising mode. Third, the high velocity of the gas in the combustion chamber (up to 30-50 m/s) resulting in a rapid compression of swirling inlet flow. The paper presents the results of tests of distributed spark ignition system powered by repetitive pulse nanosecond discharge. Dynamic pressure measurements show the increased pressure and frequency stability for nanosecond excitation in comparison with the standard spark plug. Excitation by single nanosecond high-voltage pulse and short train of pulses was examined. In all regimes the nanosecond pulsed excitation demonstrate a better performance.

  9. Repetitive transcranial magnetic stimulation and drug addiction.

    Science.gov (United States)

    Barr, Mera S; Farzan, Faranak; Wing, Victoria C; George, Tony P; Fitzgerald, Paul B; Daskalakis, Zafiris J

    2011-10-01

    Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that is now being tested for its ability to treat addiction. This review discusses current research approaches and results of studies which measured the therapeutic use of rTMS to treat tobacco, alcohol and illicit drug addiction. The research in this area is limited and therefore all studies evaluating the therapeutic use of rTMS in tobacco, alcohol or illicit drug addiction were retained including case studies through NCBI PubMed ( http://www.ncbi.nlm.nih.gov ) and manual searches. A total of eight studies were identified that examined the ability of rTMS to treat tobacco, alcohol and cocaine addiction. The results of this review indicate that rTMS is effective in reducing the level of cravings for smoking, alcohol, and cocaine when applied at high frequencies to the dorsolateral prefrontal cortex (DLPFC). Furthermore, these studies suggest that repeated sessions of high frequency rTMS over the DLPFC may be most effective in reducing the level of smoking and alcohol consumption. Although work in this area is limited, this review indicates that rTMS is a promising modality for treating drug addiction.

  10. Streptococcal toxic shock syndrome

    OpenAIRE

    Gvozdenović Ljiljana; Pasternak Janko; Milovanović Stanislav; Ivanov Dejan; Milić Saša

    2010-01-01

    Introduction. Streptococcal toxic shock syndrome is now recognized as a toxin-mediated, multisystem illness. It is characterized by an early onset of shock with multiorgan failure and continues to be associated with high morbidity and mortality, caused by group A Streptococcus pyogenes. The symptoms for staphylococcal and streptococcal toxic shock syndrome are similar. Streptococcal toxic shock syndrome was not well described until 1993, when children who had suffered from varicella pre...

  11. Biomass shock pretreatment

    Science.gov (United States)

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  12. SPECIAL PURPOSE SHOCK TUBE for BLAST ASSESSMENT

    Data.gov (United States)

    Federal Laboratory Consortium — This device is a specially designed shock tube for testing fabric samples in a controlled environment. The device determines the appropriate types of sensors to be...

  13. Scan patterns when viewing natural scenes: emotion, complexity, and repetition.

    Science.gov (United States)

    Bradley, Margaret M; Houbova, Petra; Miccoli, Laura; Costa, Vincent D; Lang, Peter J

    2011-11-01

    Eye movements were monitored during picture viewing, and effects of hedonic content, perceptual composition, and repetition on scanning assessed. In Experiment 1, emotional and neutral pictures that were figure-ground compositions or more complex scenes were presented for a 6-s free viewing period. Viewing emotional pictures or complex scenes prompted more fixations and broader scanning of the visual array, compared to neutral pictures or simple figure-ground compositions. Effects of emotion and composition were independent, supporting the hypothesis that these oculomotor indices reflect enhanced information seeking. Experiment 2 tested an orienting hypothesis by repeatedly presenting the same pictures. Although repetition altered specific scan patterns, emotional, compared to neutral, picture viewing continued to prompt oculomotor differences, suggesting that motivationally relevant cues enhance information seeking in appetitive and defensive contexts. Copyright © 2011 Society for Psychophysiological Research.

  14. Testes de força e resistência muscular: confiabilidade e predição de uma repetição máxima - Revisão e novas evidências Tests de fuerza y resistencia muscular: confiabilidad de la prediccion de una repeticion máxima - Revision y nuevas evidencias Muscular strength and endurance tests: reliability and prediction of one repetition maximum - Review and new evidences

    Directory of Open Access Journals (Sweden)

    Marta Inez Rodrigues Pereira

    2003-10-01

    % de 1RM debe ser considerada con mucha cautela.Intra-tester reliability is fundamental in determining the quality of data collected in research. Few controlled studies have reported the reliability of strength tests and, in spite of most published studies reporting it to be good (0.79 to 0.99, differences between test and retest are observed to be statistically significant. Thus, for research purposes, it is suggested that values should be taken from a second test, at least, so that changes in strength may be attributed to treatment effect and not simply to adaptation to the test protocol. The relationships between maximum strength tests and submaximal tests or anthropometric variables have been investigated in order to predict maximal strength without submitting subjects to a maximal load test, so as to avoid the risk of injury. Maximal load, or a percentage of it, is commonly used to better prescribe training. Prediction of one repetition maximum (1RM from submaximal tests seems to be good (in general, correlation coefficients > 0.90, although studies have mostly failed to cross-validate prediction equations. Thus, care should be taken especially in relation to specificity of the population, of the exercise, and performance technique when developing and applying these equations. Anthropometric variables have not proven to be good predictors of 1RM. The number of repetitions for a given % of 1RM is different for different exercises, so is the load for a given number of repetitions maximum (nRM when performed at different velocities. Exercise prescription based, indifferently, on number of repetitions or %1RM should be carefully considered.

  15. Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols

    Energy Technology Data Exchange (ETDEWEB)

    Bragard, Jean, E-mail: jbragard@unav.es; Simic, Ana; Elorza, Jorge [Department of Physics and Applied Math., University of Navarra, Pamplona (Spain); Grigoriev, Roman O.; Fenton, Flavio H. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Cherry, Elizabeth M. [School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623 (United States); Gilmour, Robert F. [University of Prince Edward Island, Charlottetown C1A 4P3 (Canada); Otani, Niels F. [School of Mathematical Sciences, Rochester Institute of Technology, Rochester, New York 14623 (United States); Department of Biomedical Sciences, Cornell University, Ithaca, New York 14853 (United States)

    2013-12-15

    In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one–dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 10{sup 6} simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation.

  16. Effect of leading edge sweep on shock-shock interference at Mach 8

    Science.gov (United States)

    Glass, Christopher E.; Wieting, Allan R.; Holden, Michael S.

    1989-01-01

    These Mach 8 experimental results are applicable to the details of a shock-shock interference that may occur on an engine inlet of a hypersonic vehicle from a swept forebody shock interacting with a swept cowl leading edge bow shock or from a swept splitter plate shock interacting with a swept fuel injection strut bow shock. Peak surface pressure and heat transfer rate on the cylinder were about 10 and 30 times the undisturbed flow stagnation point value, respectively, for the 0 deg sweep test. A comparison of the 15 deg and 30 deg swept results with the 0 deg swept results shows that peak pressure was reduced about 13 percent and 44 percent, respectively, and peak heat transfer rate was reduced about 7 percent and 27 percent, respectively.

  17. Gut as source of sepsis after hemorrhagic shock

    Energy Technology Data Exchange (ETDEWEB)

    Sori, A.J.; Rush, B.F. Jr.; Lysz, T.W.; Smith, S.; Machiedo, G.W.

    1988-02-01

    In a model of severe hemorrhagic shock in rats, blood culture findings became positive within 2 to 4 hours of shock. The organisms cultured were primarily gram-negative. To test the hypothesis that the gut was the source of the bacteria, E. coli labeled with carbon-14 oleic acid were fed to rats undergoing hemorrhagic shock. Their plasma was then assayed for carbon-14 activity. Seven of the 14 shocked animals demonstrated increased plasma carbon-14 activity during or after shock. The mortality rate was 100 percent 80 hours postshock, and all animals had E. coli on subsequent blood culture. The seven rats without increased plasma carbon-14 activity had a survival rate of 83 percent postshock. Sham-shocked animals did not exhibit plasma carbon-14 levels greater than the background levels. These data suggest that bacterial translocation occurs during hemorrhagic shock and that the gut is the source of the bacteremia seen during hemorrhagic shock.

  18. Barrier experiment: Shock initiation under complex loading

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-12

    The barrier experiments are a variant of the gap test; a detonation wave in a donor HE impacts a barrier and drives a shock wave into an acceptor HE. The question we ask is: What is the trade-off between the barrier material and threshold barrier thickness to prevent the acceptor from detonating. This can be viewed from the perspective of shock initiation of the acceptor subject to a complex pressure drive condition. Here we consider key factors which affect whether or not the acceptor undergoes a shock-to-detonation transition. These include the following: shock impedance matches for the donor detonation wave into the barrier and then the barrier shock into the acceptor, the pressure gradient behind the donor detonation wave, and the curvature of detonation front in the donor. Numerical simulations are used to illustrate how these factors affect the reaction in the acceptor.

  19. Shock-induced devolatilization of calcite

    Science.gov (United States)

    Boslough, M. B.; Ahrens, T. J.; Vizgirda, J.; Becker, R. H.; Epstein, S.

    1982-01-01

    Experimental measurements of the release adiabats by Vizgirda (1981) indicate that substantial vaporization takes place upon release from shock pressures of 37 GPa for calcite and 14 GPa for aragonite. The present investigation includes the first controlled partial vaporization experiments on calcite. The experiments were conducted to test the predictions of the release adiabat experiments. The quantities of the gaseous species produced from shocked calcite and their carbon and oxygen isotopic compositions were determined, and the shock-induced effect on the Mn(2+) electron spin resonance spectrum in the shock-recovered calcite was observed. On the basis of the obtained results, it is concluded that shock stresses at the 17-18 GPa level give rise to volatilization of 0.03-0.3 (mole) percent of calcite to CO2 and CO. The devolatilization of calcite occurs at low pressure at significantly lower entropy densities than predicted on the basis of thermodynamic continuum models.

  20. Simulating radiative shocks in nozzle shock tubes

    Science.gov (United States)

    van der Holst, B.; Tóth, G.; Sokolov, I. V.; Daldorff, L. K. S.; Powell, K. G.; Drake, R. P.

    2012-06-01

    We use the recently developed Center for Radiative Shock Hydrodynamics (CRASH) code to numerically simulate laser-driven radiative shock experiments. These shocks are launched by an ablated beryllium disk and are driven down xenon-filled plastic tubes. The simulations are initialized by the two-dimensional version of the Lagrangian Hyades code which is used to evaluate the laser energy deposition during the first 1.1 ns. Later times are calculated with the CRASH code. CRASH solves for the multi-material hydrodynamics with separate electron and ion temperatures on an Eulerian block-adaptive-mesh and includes a multi-group flux-limited radiation diffusion and electron thermal heat conduction. The goal of the present paper is to demonstrate the capability to simulate radiative shocks of essentially three-dimensional experimental configurations, such as circular and elliptical nozzles. We show that the compound shock structure of the primary and wall shock is captured and verify that the shock properties are consistent with order-of-magnitude estimates. The synthetic radiographs produced can be used for comparison with future nozzle experiments at high-energy-density laser facilities.

  1. Simulating radiative shocks in nozzle shock tubes

    CERN Document Server

    van der Holst, B; Sokolov, I V; Daldorff, L K S; Powell, K G; Drake, R P

    2011-01-01

    We use the recently developed Center for Radiative Shock Hydrodynamics (CRASH) code to numerically simulate laser-driven radiative shock experiments. These shocks are launched by an ablated beryllium disk and are driven down xenon-filled plastic tubes. The simulations are initialized by the two-dimensional version of the Lagrangian Hyades code which is used to evaluate the laser energy deposition during the first 1.1ns. The later times are calculated with the CRASH code. This code solves for the multi-material hydrodynamics with separate electron and ion temperatures on an Eulerian block-adaptive-mesh and includes a multi-group flux-limited radiation diffusion and electron thermal heat conduction. The goal of the present paper is to demonstrate the capability to simulate radiative shocks of essentially three-dimensional experimental configurations, such as circular and elliptical nozzles. We show that the compound shock structure of the primary and wall shock is captured and verify that the shock properties a...

  2. A longitudinal investigation of perfectionism and repetitive negative thinking in perinatal depression.

    Science.gov (United States)

    Egan, Sarah J; Kane, Robert T; Winton, Karen; Eliot, Catherine; McEvoy, Peter M

    2017-10-01

    Repetitive negative thinking and perfectionism have both been proposed as processes that are related to depressive symptoms. The purpose of this study was to investigate concurrent and prospective relationships between antenatal and postnatal depression, perfectionism, and repetitive negative thinking. A longitudinal design was used and 71 women were followed from their third trimester of pregnancy to six weeks post birth. A structural equation model was tested with antenatal perfectionism predicting antenatal repetitive negative thinking, perfectionism predicting postnatal depression, and antenatal repetitive negative thinking predicting antenatal and postnatal depression. The final model provided an adequate fit to the data but the pathway from antenatal repetitive negative thinking to postnatal depression was not significant. The findings provide support for the role of perfectionism and repetitive negative thinking in the onset and maintenance of perinatal symptoms of depression. It is suggested that future research investigates the efficacy of targeting repetitive negative thinking and perfectionism in pregnancy to examine if this can reduce perinatal depression. Copyright © 2017. Published by Elsevier Ltd.

  3. The Prevalence and Phenomenology of Repetitive Behavior in Genetic Syndromes

    Science.gov (United States)

    Moss, Joanna; Oliver, Chris; Arron, Kate; Burbidge, Cheryl; Berg, Katy

    2009-01-01

    We investigated the prevalence and phenomenology of repetitive behavior in genetic syndromes to detail profiles of behavior. The Repetitive Behaviour Questionnaire (RBQ) provides fine-grained identification of repetitive behaviors. The RBQ was employed to examine repetitive behavior in Angelman (N = 104), Cornelia de Lange (N = 101), Cri-du-Chat…

  4. Converging shocks in elastic-plastic solids.

    Science.gov (United States)

    Ortega, A López; Lombardini, M; Hill, D J

    2011-11-01

    We present an approximate description of the behavior of an elastic-plastic material processed by a cylindrically or spherically symmetric converging shock, following Whitham's shock dynamics theory. Originally applied with success to various gas dynamics problems, this theory is presently derived for solid media, in both elastic and plastic regimes. The exact solutions of the shock dynamics equations obtained reproduce well the results obtained by high-resolution numerical simulations. The examined constitutive laws share a compressible neo-Hookean structure for the internal energy e=e(s)(I(1))+e(h)(ρ,ς), where e(s) accounts for shear through the first invariant of the Cauchy-Green tensor, and e(h) represents the hydrostatic contribution as a function of the density ρ and entropy ς. In the strong-shock limit, reached as the shock approaches the axis or origin r=0, we show that compression effects are dominant over shear deformations. For an isothermal constitutive law, i.e., e(h)=e(h)(ρ), with a power-law dependence e(h) is proportional to ρ(α), shock dynamics predicts that for a converging shock located at r=R(t) at time t, the Mach number increases as M is proportional to [log(1/R)](α), independently of the space index s, where s=2 in cylindrical geometry and 3 in spherical geometry. An alternative isothermal constitutive law with p(ρ) of the arctanh type, which enforces a finite density in the strong-shock limit, leads to M is proportional to R(-(s-1)) for strong shocks. A nonisothermal constitutive law, whose hydrostatic part e(h) is that of an ideal gas, is also tested, recovering the strong-shock limit M is proportional to R(-(s-1)/n(γ)) originally derived by Whitham for perfect gases, where γ is inherently related to the maximum compression ratio that the material can reach, (γ+1)/(γ-1). From these strong-shock limits, we also estimate analytically the density, radial velocity, pressure, and sound speed immediately behind the shock. While the

  5. Converging shocks in elastic-plastic solids

    Science.gov (United States)

    López Ortega, A.; Lombardini, M.; Hill, D. J.

    2011-11-01

    We present an approximate description of the behavior of an elastic-plastic material processed by a cylindrically or spherically symmetric converging shock, following Whitham's shock dynamics theory. Originally applied with success to various gas dynamics problems, this theory is presently derived for solid media, in both elastic and plastic regimes. The exact solutions of the shock dynamics equations obtained reproduce well the results obtained by high-resolution numerical simulations. The examined constitutive laws share a compressible neo-Hookean structure for the internal energy e=es(I1)+eh(ρ,ς), where es accounts for shear through the first invariant of the Cauchy-Green tensor, and eh represents the hydrostatic contribution as a function of the density ρ and entropy ς. In the strong-shock limit, reached as the shock approaches the axis or origin r=0, we show that compression effects are dominant over shear deformations. For an isothermal constitutive law, i.e., eh=eh(ρ), with a power-law dependence eh∝ρα, shock dynamics predicts that for a converging shock located at r=R(t) at time t, the Mach number increases as M∝[log(1/R)]α, independently of the space index s, where s=2 in cylindrical geometry and 3 in spherical geometry. An alternative isothermal constitutive law with p(ρ) of the arctanh type, which enforces a finite density in the strong-shock limit, leads to M∝R-(s-1) for strong shocks. A nonisothermal constitutive law, whose hydrostatic part eh is that of an ideal gas, is also tested, recovering the strong-shock limit M∝R-(s-1)/n(γ) originally derived by Whitham for perfect gases, where γ is inherently related to the maximum compression ratio that the material can reach, (γ+1)/(γ-1). From these strong-shock limits, we also estimate analytically the density, radial velocity, pressure, and sound speed immediately behind the shock. While the hydrostatic part of the energy essentially commands the strong-shock behavior, the shear

  6. Shock wave interactions with liquid sheets

    Science.gov (United States)

    Jeon, H.; Eliasson, V.

    2017-04-01

    Shock wave interactions with a liquid sheet are investigated by impacting planar liquid sheets of varying thicknesses with a planar shock wave. A square frame was designed to hold a rectangular liquid sheet, with a thickness of 5 or 10 mm, using plastic membranes and cotton wires to maintain the planar shape and minimize bulge. The flat liquid sheet, consisting of either water or a cornstarch and water mixture, was suspended in the test section of a shock tube. Incident shock waves with Mach numbers of M_s = 1.34 and 1.46 were considered. A schlieren technique with a high-speed camera was used to visualize the shock wave interaction with the liquid sheets. High-frequency pressure sensors were used to measure wave speed, overpressure, and impulse both upstream and downstream of the liquid sheet. Results showed that no transmitted shock wave could be observed through the liquid sheets, but compression waves induced by the shock-accelerated liquid coalesced into a shock wave farther downstream. A thicker liquid sheet resulted in a lower peak overpressure and impulse, and a cornstarch suspension sheet showed a higher attenuation factor compared to a water sheet.

  7. 激波风洞气动力试验不确定度影响因素分析%Analysis of uncertainty for aerodynamic test in shock tunnel

    Institute of Scientific and Technical Information of China (English)

    王刚; 唐志共; 吕治国; 姜华; 赵荣娟

    2013-01-01

    Referring to the method of uncertainty analysis for wind tunnel recommended by AGARD and AIAA and according to the characteristic of shock tunnel, the important error sources were determined in aerodynamic force measurement, and the uncertainty of aerodynamic test data can be estimated in shock tunnel. The test data were obtained with B-2 standard model in shock tunnel. By changing each error source, the primary parameters which affect uncertainty in aerodynamic test are confirmed. The results indicate that pitot pressure and total pressure have notable effect on parameters of flow field, while the former is more important. It is effective to improve the quality of aerodynamic test data by decreasing the bias limit of pitot pressure and total pressure in shock tunnel.%参考北大西洋公约组织和AIAA推荐的风洞试验数据不确定度计算方法,结合激波风洞运行特点,确定激波风洞气动力试验的主要误差源,计算激波风洞B-2标模气动力测量结果的不确定度.采用改变单一变量的方法计算主要误差源对测量结果不确定度的影响程度,辨析对不确定度起主要作用的基本参数.计算结果表明:皮托压力和总压的测量结果对流场参数影响显著,皮托压力的测量结果比总压测量结果对流场参数与气动力测量结果影响更大;降低皮托压力和总压的偏离极限,有利于提高激波风洞气动力试验数据的质量.

  8. Likelihood methods and classical burster repetition

    CERN Document Server

    Graziani, C; Graziani, Carlo; Lamb, Donald Q

    1995-01-01

    We develop a likelihood methodology which can be used to search for evidence of burst repetition in the BATSE catalog, and to study the properties of the repetition signal. We use a simplified model of burst repetition in which a number N_{\\rm r} of sources which repeat a fixed number of times N_{\\rm rep} are superposed upon a number N_{\\rm nr} of non-repeating sources. The instrument exposure is explicitly taken into account. By computing the likelihood for the data, we construct a probability distribution in parameter space that may be used to infer the probability that a repetition signal is present, and to estimate the values of the repetition parameters. The likelihood function contains contributions from all the bursts, irrespective of the size of their positional errors --- the more uncertain a burst's position is, the less constraining is its contribution. Thus this approach makes maximal use of the data, and avoids the ambiguities of sample selection associated with data cuts on error circle size. We...

  9. Teste de estimulação repetitiva no músculo ancôneo para diagnóstico da miastenia grave: mapeamento da sua área de placa motora Repetitive stimulation test on the anconeus muscle for the diagnosis of myasthenia gravis: the mapping of its motor end-plate area

    Directory of Open Access Journals (Sweden)

    Maria das Graças Wanderley S. Coriolano

    2007-06-01

    Full Text Available OBJETIVO: Mapear a área de placa motora do músculo ancôneo para definir a melhor localização dos eletrodos de registro em testes de estimulação repetitiva (TER no diagnóstico dos distúrbios da transmissão neuromuscular. MÉTODO: Registramos o potencial de ação composto do músculo ancôneo sobre a pele que o recobre, após estimulação do ramo que o inerva. Analisando as formas de onda registradas em cada ponto da pele foi possível definir a área de placa. RESULTADOS: A área de placa motora do ancôneo é uma linha paralela à borda da ulna. O melhor local de colocação do eletrodo "ativo" de registro situa-se cerca de 2 cm distal ao olécrano e 1 cm lateral à borda da ulna. CONCLUSÃO: A realização de TER no músculo ancôneo é simples e bem tolerada. Com a estimulação do ancôneo o antebraço praticamente não se move, sendo o procedimento livre de artefatos de movimento.PURPOSE: To map the motor end-plate area of the anconeus muscle and define the best place for positioning the recording electrodes in repetitive stimulation tests (RST for the diagnosis of neuromuscular transmission disorders. METHOD: The compound muscle action potential of the anconeus was recorded after stimulating the motor branch of the radial nerve that innervates it. By analyzing the waveforms registered at each point of the skin we were able to define the motor end-plate area. RESULTS: The motor end-plate area of the anconeus is a line parallel to the ulna border. The best place for placing the "active" recording electrode is about 2cm distal to the olecranon and 1 cm lateral to the border of the ulna. CONCLUSION: Performing RST in the anconeus muscle is simple and well tolerated. Stimulation of the anconeus almost doesn't move the forearm and the procedure is virtually free of movement artifacts.

  10. A referential theory of the repetition-induced truth effect.

    Science.gov (United States)

    Unkelbach, Christian; Rom, Sarah C

    2017-03-01

    People are more likely to judge repeated statements as true compared to new statements, a phenomenon known as the illusory truth effect. The currently dominant explanation is an increase in processing fluency caused by prior presentation. We present a new theory to explain this effect. We assume that people judge truth based on coherent references for statements in memory. Due to prior presentation, repeated statements have more coherently linked references; thus, a repetition-induced truth effect follows. Five experiments test this theory. Experiment 1-3 show that both the amount and the coherence of references for a repeated statement influence judged truth. Experiment 4 shows that people also judge new statements more likely "true" when they share references with previously presented statements. Experiment 5 realizes theoretically predicted conditions under which repetition should not influence judged truth. Based on these data, we discuss how the theory relates to other explanations of repetition-induced truth and how it may integrate other truth-related phenomena and belief biases. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Route Repetition and Route Retracing: Effects of Cognitive Aging

    Directory of Open Access Journals (Sweden)

    Jan Malte Wiener

    2012-05-01

    Full Text Available Retracing a recently traveled route is a frequent navigation task when learning novel routes or exploring unfamiliar environments. In the present study we utilized virtual environments technology to investigate age-related differences in repeating and retracing a learned route. In the training phase of the experiment participants were guided along a route consisting of multiple intersections each featuring one unique landmark. In the subsequent test phase, they were guided along short sections of the route and asked to indicate overall travel direction (repetition or retracing, the direction required to continue along the route, and the next landmark they would encounter. Results demonstrate age-related deficits in all three tasks. More specifically, in contrast to younger participants, the older participants had greater problems during route retracing than during route repetition. While route repetition can be solved with egocentric response or route strategies, successfully retracing a route requires allocentric processing. The age-related deficits in route retracing are discussed in the context of impaired allocentric processing and shifts from allocentric to egocentric navigation strategies as a consequence of age-related hippocampal degeneration.

  12. Hypersonic wave drag reduction performance of cylinders with repetitive laser energy depositions

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J; Hong, Y J; Li, Q; Huang, H, E-mail: fangjuan314@163.com [Academy of Equipment Command and Technology, Post Box 3380-86, Huairou Dis. Beijing 101416 (China)

    2011-02-01

    It has been widely research that wave drag reduction on hypersonic vehicle by laser energy depositions. Using laser energy to reduce wave drag can improve vehicle performance. A second order accurate scheme based on finite-difference method and domain decomposition of structural grid is used to compute the drag performance of cylinders in a hypersonic flow of Mach number 2 at altitude of 15km with repetitive energy depositions. The effects of frequency on drag reduction are studied. The calculated results show: the recirculation zone is generated due to the interaction between bow shock over the cylinder and blast wave produced by energy deposition, and a virtual spike which is supported by an axis-symmetric recirculation, is formed in front of the cylinder. By increasing the repetitive frequency, the drag is reduced and the oscillation of the drag is decreased; however, the energy efficiency decreases by increasing the frequency.

  13. Understanding communicative actions: a repetitive TMS study.

    Science.gov (United States)

    Stolk, Arjen; Noordzij, Matthijs L; Volman, Inge; Verhagen, Lennart; Overeem, Sebastiaan; van Elswijk, Gijs; Bloem, Bas; Hagoort, Peter; Toni, Ivan

    2014-02-01

    Despite the ambiguity inherent in human communication, people are remarkably efficient in establishing mutual understanding. Studying how people communicate in novel settings provides a window into the mechanisms supporting the human competence to rapidly generate and understand novel shared symbols, a fundamental property of human communication. Previous work indicates that the right posterior superior temporal sulcus (pSTS) is involved when people understand the intended meaning of novel communicative actions. Here, we set out to test whether normal functioning of this cerebral structure is required for understanding novel communicative actions using inhibitory low-frequency repetitive transcranial magnetic stimulation (rTMS). A factorial experimental design contrasted two tightly matched stimulation sites (right pSTS vs left MT+, i.e., a contiguous homotopic task-relevant region) and tasks (a communicative task vs a visual tracking task that used the same sequences of stimuli). Overall task performance was not affected by rTMS, whereas changes in task performance over time were disrupted according to TMS site and task combinations. Namely, rTMS over pSTS led to a diminished ability to improve action understanding on the basis of recent communicative history, while rTMS over MT+ perturbed improvement in visual tracking over trials. These findings qualify the contributions of the right pSTS to human communicative abilities, showing that this region might be necessary for incorporating previous knowledge, accumulated during interactions with a communicative partner, to constrain the inferential process that leads to action understanding. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Impaired Fracture Healing after Hemorrhagic Shock

    Directory of Open Access Journals (Sweden)

    Philipp Lichte

    2015-01-01

    Full Text Available Impaired fracture healing can occur in severely injured patients with hemorrhagic shock due to decreased soft tissue perfusion after trauma. We investigated the effects of fracture healing in a standardized pressure controlled hemorrhagic shock model in mice, to test the hypothesis that bleeding is relevant in the bone healing response. Male C57/BL6 mice were subjected to a closed femoral shaft fracture stabilized by intramedullary nailing. One group was additionally subjected to pressure controlled hemorrhagic shock (HS, mean arterial pressure (MAP of 35 mmHg for 90 minutes. Serum cytokines (IL-6, KC, MCP-1, and TNF-α were analyzed 6 hours after shock. Fracture healing was assessed 21 days after fracture. Hemorrhagic shock is associated with a significant increase in serum inflammatory cytokines in the early phase. Histologic analysis demonstrated a significantly decreased number of osteoclasts, a decrease in bone quality, and more cartilage islands after hemorrhagic shock. μCT analysis showed a trend towards decreased bone tissue mineral density in the HS group. Mechanical testing revealed no difference in tensile failure. Our results suggest a delay in fracture healing after hemorrhagic shock. This may be due to significantly diminished osteoclast recruitment. The exact mechanisms should be studied further, particularly during earlier stages of fracture healing.

  15. THE EFFECTS OF AREA CONTRACTION ON SHOCK WAVE STRENGTH AND PEAK PRESSURE IN SHOCK TUBE

    Directory of Open Access Journals (Sweden)

    A. M. Mohsen

    2012-06-01

    Full Text Available This paper presents an experimental investigation into the effects of area contraction on shock wave strength and peak pressure in a shock tube. The shock tube is an important component of the short duration, high speed fluid flow test facility, available at the Universiti Tenaga Nasional (UNITEN, Malaysia. The area contraction was facilitated by positioning a bush adjacent to the primary diaphragm section, which separates the driver and driven sections. Experimental measurements were performed with and without the presence of the bush, at various diaphragm pressure ratios, which is the ratio of air pressure between the driver (high pressure and driven (low pressure sections. The instantaneous static pressure variations were measured at two locations close to the driven tube end wall, using high sensitivity pressure sensors, which allow the shock wave strength, shock wave speed and peak pressure to be analysed. The results reveal that the area contraction significantly reduces the shock wave strength, shock wave speed and peak pressure. At a diaphragm pressure ratio of 10, the shock wave strength decreases by 18%, the peak pressure decreases by 30% and the shock wave speed decreases by 8%.

  16. High-repetition rate industrial TEA CO2 laser with average output power of 1.5 kW

    Science.gov (United States)

    Wan, Chongyi; Liu, Shiming; Zhou, Jinwen; Qi, Jilan; Yang, Xiaola; Wu, Jin; Tan, Rongqing; Wang, Lichun; Mei, Qichu

    1995-03-01

    High power high repetition rate TEA CO2 laser has potential importance in material processing such as shock hardening, glazing, drilling, welding, and cutting for high damage threshold materials, as well as in chemical reaction and isotope separation. This paper describes a transverse-flow closed-cycle UV-preionized TEA CO2 laser with peak pulse power of 20 MW, maximum average power of 1.5 KW at repetition rate of 300 HZ. The laser has compact constructure of gas flow circulation system using tangential fans. With addition of small amounts of H2 and CO to the normal CO2-N2-He gas mixture, one filling sealed operating lifetime is up to millions of pulses. A novel spark gap switch has been developed for very high repetition rate laser discharge in the condition of high pulse power.

  17. Restricted and repetitive behaviours, sensory processing and cognitive style in children with autism spectrum disorders.

    Science.gov (United States)

    Chen, Yu-Han; Rodgers, Jacqui; McConachie, Helen

    2009-04-01

    Many individuals with autism tend to focus on details. It has been suggested that this cognitive style may underlie the presence of stereotyped routines, repetitive interests and behaviours, and both relate in some way to sensory abnormalities. Twenty-nine children with diagnosis of high functioning autism or Asperger syndrome completed the Embedded Figures Test (EFT), and their parents the Short Sensory Profile and Childhood Routines Inventory. Significant correlations were found between degree of sensory abnormalities and amount of restricted and repetitive behaviours reported. Repetitive behaviours, age and IQ significantly predicted completion time on the EFT. The results suggest a cognitive link between an individual's detail-focused cognitive style and their repetitiveness. No such relationship was found with sensory processing abnormalities, which may arise at a more peripheral level of functioning.

  18. Condensate Accretion in Shock Tube's Expansion Fan

    Science.gov (United States)

    Mezonlin, Ephrem-Denis; DeSilva, Upul P.; Hunte, F.; Johnson, Joseph A., III

    1997-01-01

    It has been shown that turbulence and temperature influence the droplet sizes in expansion fan induced condensation by studying the Rayleigh scattering from one port in our shock tube's test section. We have modified our set-up so as to allow, using two ports, the real time measurement of the influence of turbulence and temperature on the rate at which these droplets grow. To do this, we looked at the Rayleigh scattering from two different ports for ten Reynolds numbers at five different temperatures. We modeled the time of flight of droplets, using the equations of one-dimensional gas dynamics and the measured shock wave speed in shock tube's driven section.

  19. Testis-enriched heat shock protein A2 (HSPA2): Adaptive advantages of the birds with internal testes over the mammals with testicular descent.

    Science.gov (United States)

    Padhi, Abinash; Ghaly, Mona M; Ma, Li

    2016-01-06

    The molecular chaperone heat shock protein A2 (HSPA2), a member of the 70 kDa heat shock protein (HSP70) family, plays an important role in spermatogenesis and male fertility. Although HSPA2 is evolutionarily highly conserved across the metazoan lineages, the observation of striking differences in temperature-sensitive expressions, testicular physiology, spermatogenesis, as well as its role in male fertility indicates that avian and mammalian HSPA2 may exhibit distinct evolutionary trajectory. The present study reports that while mammalian HSPA2 is constrained by intense purifying selection, avian HSPA2 has been subjected to positive selection. The majority of the positively selected amino acid residues fall on the α-helix and β-sheets of the peptide-binding domain located at the carboxyl-terminal region of the avian HSPA2. The detection of positively selected sites at the helix and β-sheets, which are less tolerant to molecular adaptation, indicates an important functional consequence and contribution to the structural and functional diversification of the avian HSPA2. Collectively, avian HSPA2 may have an adaptive advantage over the mammals in response to heat stress, and therefore, mammals with testicular descent may be at a greater risk in the event of scrotal temperature rise.

  20. Shock Tubes and Shock Tunnels: Design and Experiments

    Science.gov (United States)

    2009-09-01

    another gas (driver gas). After the rupture of this diaphragm the driver gas, acting as a piston expands into the low pressure chamber and generates a...interface, acts like a well for the non-dissipative part of the test gas and a loss of this gas occurs through the interface in the boundary layer (Fig.2...photography or cinematography [(x, t) or (y, t) diagrams]. Examples of shock tube flows are thus represented in Figs.14 and 15 [30]. (a

  1. Shock desensitizing of solid explosive

    Energy Technology Data Exchange (ETDEWEB)

    Davis, William C [Los Alamos National Laboratory

    2010-01-01

    Solid explosive can be desensitized by a shock wave too weak to initiate it promptly, and desensitized explosive does not react although its chemical composition is almost unchanged. A strong second shock does not cause reaction until it overtakes the first shock. The first shock, if it is strong enough, accelerates very slowly at first, and then more rapidly as detonation approaches. These facts suggest that there are two competing reactions. One is the usual explosive goes to products with the release of energy, and the other is explosive goes to dead explosive with no chemical change and no energy release. The first reaction rate is very sensitive to the local state, and the second is only weakly so. At low pressure very little energy is released and the change to dead explosive dominates. At high pressure, quite the other way, most of the explosive goes to products. Numerous experiments in both the initiation and the full detonation regimes are discussed and compared in testing these ideas.

  2. Sound velocities in shocked liquid deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, N.C.; Nellis, W.J.; Ross, M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    1998-07-01

    Recent measurements of shock temperatures and laser-driven Hugoniot measurements of shocked liquid deuterium strongly indicate that molecular dissociation is important above 20 GPa. Since the effect of dissociation is small on the Hugoniot pressure up to the 30 GPa limit of conventional impact experiments, other methods must be used to test our understanding of the physics of highly compressed deuterium in this regime. We have recently performed experiments to measure the sound velocity of deuterium which test the isentropic compressibility, a derivative quantity. We used the shock overtake method to measure the shock velocity at 28 GPa. These preliminary data provide support for a recently developed molecular dissociation model. {copyright} {ital 1998 American Institute of Physics.}

  3. Toxic Shock Syndrome (For Parents)

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Toxic Shock Syndrome KidsHealth > For Parents > Toxic Shock Syndrome Print ... en español Síndrome de shock tóxico About Toxic Shock Syndrome Toxic shock syndrome (TSS) is a serious ...

  4. Shock equation of state properties of concrete

    Energy Technology Data Exchange (ETDEWEB)

    Grady, D.

    1996-03-01

    Unique shock compression experiments have been developed and pursued which provide material equation of state data for dynamic strength, pore crush, shock Hugoniot and adiabatic decompression. Experimental data have been obtained on an aggregate concrete to Hugoniot pressures of 25 GPa. New analytic methods were developed to extract equation-of-state properties from dynamic test data. Unexpected residual strain results are compared with expected thermal expansion and dilatancy properties of concrete.

  5. Streptococcal toxic shock syndrome

    Directory of Open Access Journals (Sweden)

    Gvozdenović Ljiljana

    2010-01-01

    Full Text Available Introduction. Streptococcal toxic shock syndrome is now recognized as a toxin-mediated, multisystem illness. It is characterized by an early onset of shock with multiorgan failure and continues to be associated with high morbidity and mortality, caused by group A Streptococcus pyogenes. The symptoms for staphylococcal and streptococcal toxic shock syndrome are similar. Streptococcal toxic shock syndrome was not well described until 1993, when children who had suffered from varicella presented roughly 2-4 weeks later with a clinical syndrome highly suggestive of toxic shock syndrome. Characteristics, complications and therapy. It is characterized by a sudden onset of fever, chills, vomiting, diarrhea, muscle aches and rash. It can rapidly progress to severe and intractable hypotension and multisystem dysfunction. Almost every organ system can be involved. Complications of streptococcal toxic shock syndrome may include kidney failure, liver failure and even death. Crystalloids and inotropic agents are used to treat the hypovolemic shock aggressively, with close monitoring of the patient’s mean arterial pressure and central venous pressure. An immediate and aggressive management of hypovolemic shock is essential in streptococcal toxic shock syndrome. Targeted antibiotics are indicated; penicillin or a betalactam antibiotic is used for treating group A streptococci, and clindamycin has emerged as a key portion of the standard treatment.

  6. Anti-Shock Garment

    Science.gov (United States)

    1996-01-01

    Ames Research Center developed a prototype pressure suit for hemophiliac children, based on research of astronauts' physiological responses in microgravity. Zoex Corporation picked up the design and patents and developed an anti-shock garment for paramedic use. Marketed by Dyna Med, the suit reverses the effect of shock on the body's blood distribution by applying counterpressure to the legs and abdomen, returning blood to vital organs and stabilizing body pressure until the patient reaches a hospital. The DMAST (Dyna Med Anti-Shock Trousers) employ lower pressure than other shock garments, and are non-inflatable.

  7. Chiral Shock Waves

    CERN Document Server

    Sen, Srimoyee

    2016-01-01

    We study shock waves in relativistic chiral matter. We argue that the conventional Rankine- Hugoinot relations are modified due to the presence of chiral transport phenomena. We show that the entropy discontinuity in a weak shock wave is linearly proportional to the pressure discontinuity when the effect of chiral transport becomes sufficiently large. We also show that rarefaction shock waves, which do not exist in usual nonchiral fluids, can appear in chiral matter. These features are exemplified by shock propagation in dense neutrino matter in the hydrodynamic regime.

  8. The neurobiology of repetitive behavior : of mice…

    NARCIS (Netherlands)

    Langen, Marieke; Kas, Martien J H; Staal, Wouter G; van Engeland, Herman; Durston, Sarah

    2011-01-01

    Repetitive and stereotyped behavior is a prominent element of both animal and human behavior. Similar behavior is seen across species, in diverse neuropsychiatric disorders and in key phases of typical development. This raises the question whether these similar classes of behavior are caused by simi

  9. Large-scale detection of repetitions.

    Science.gov (United States)

    Smyth, W F

    2014-05-28

    Combinatorics on words began more than a century ago with a demonstration that an infinitely long string with no repetitions could be constructed on an alphabet of only three letters. Computing all the repetitions (such as ∙∙∙TTT ∙∙∙ or ∙∙∙ CGACGA ∙∙∙ ) in a given string x of length n is one of the oldest and most important problems of computational stringology, requiring time in the worst case. About a dozen years ago, it was discovered that repetitions can be computed as a by-product of the Θ(n)-time computation of all the maximal periodicities or runs in x. However, even though the computation is linear, it is also brute force: global data structures, such as the suffix array, the longest common prefix array and the Lempel-Ziv factorization, need to be computed in a preprocessing phase. Furthermore, all of this effort is required despite the fact that the expected number of runs in a string is generally a small fraction of the string length. In this paper, I explore the possibility that repetitions (perhaps also other regularities in strings) can be computed in a manner commensurate with the size of the output.

  10. Verbal Repetitions and Echolalia in Alzheimer's Discourse

    Science.gov (United States)

    Da Cruz, Fernanda Miranda

    2010-01-01

    This article reports on an investigation of echolalic repetition in Alzheimer's disease (AD). A qualitative analysis of data from spontaneous conversations with MHI, a woman with AD, is presented. The data come from the DALI Corpus, a corpus of spontaneous conversations involving subjects with AD. This study argues that echolalic effects can be…

  11. Neurobehavioural Correlates of Abnormal Repetitive Behaviour

    Directory of Open Access Journals (Sweden)

    R. A. Ford

    1991-01-01

    Full Text Available Conditions in which echolalia and echopraxia occur are reviewed, followed by an attempt to elicit possible mechanisms of these phenomena. A brief description of stereotypical and perseverative behaviour and obsessional phenomena is given. It is suggested that abnormal repetitive behaviour may occur partly as a result of central dopaminergic dysfunction.

  12. Reducing Repetitive Speech: Effects of Strategy Instruction.

    Science.gov (United States)

    Dipipi, Caroline M.; Jitendra, Asha K.; Miller, Judith A.

    2001-01-01

    This article describes an intervention with an 18-year-old young woman with mild mental retardation and a seizure disorder, which focused on her repetitive echolalic verbalizations. The intervention included time delay, differential reinforcement of other behaviors, and self-monitoring. Overall, the intervention was successful in facilitating…

  13. Verbal Repetitions and Echolalia in Alzheimer's Discourse

    Science.gov (United States)

    Da Cruz, Fernanda Miranda

    2010-01-01

    This article reports on an investigation of echolalic repetition in Alzheimer's disease (AD). A qualitative analysis of data from spontaneous conversations with MHI, a woman with AD, is presented. The data come from the DALI Corpus, a corpus of spontaneous conversations involving subjects with AD. This study argues that echolalic effects can be…

  14. Background music for repetitive task performance of severely retarded individuals.

    Science.gov (United States)

    Richman, J S

    1976-11-01

    Environmental manipulation in the form of specific tempo background music was used to assist in the habilitation of severely retarded persons. Thirty institutionalized retarded males were tested on a repetitive manual performance task judged to be similar to the type of tasks found in sheltered workshops. Each subject received each of the background treatments noncontingently: no music, slow tempo music, regular tempo music, fast tempo music. The results indicated that the regular tempo of background music facilitated the greatest improvement in performance, suggesting that the effect of music on performance is more complex than the issue of contingent presentation.

  15. The HSP expression of passive repetitive plyometric trained skeletal muscle.

    Science.gov (United States)

    Hsu, Cheng-Chen; Hsu, Mei-Chich; Huang, Mao-Shung; Chen, Chuan-Show; Shiang, Tzyy-Yuang; Wang, Chiou-Huey; Chen, Tzuping; Su, Borcherng

    2005-01-01

    This study aims to understand the effect of ten-week passive repetitive plyometric (PRP) training on human skeletal muscle and the application of PRP training for performance. Vastus lateralis of nine candidates were aspirated before (pre) and after (post) PRP training. Histochemical approaches with regular hematoxylene-eosin (HE) and Mallory's phosphotungstic acid hematoxylin (PTAH) stains were used to demonstrate the changes of muscle fibers. Immunohistochemical studies with heat shock protein (anti-hsp72, Stressgen, Canada) were employed to display cellular activities. Each set of slides was quantitatively analyzed by using a modified morphometric method (Russ and Dehoff, 1999) on a Nikon ECLIPSE 80i microscope, equipped with an Evolution VF COOLED color video camera, and the Image-Pro Plus software (5.0 for Win; Media Cybernetics, USA). Finally, hsp72 mRNAs of both pre-PRP and post-PRP specimens were amplified through RT-PCR. Signal intensities were read by a densitometer and analyzed through the SPSS (11.0 for Win) statistically. Post-PRP muscle cells demonstrated hypertrophic change with increased cellular content and a narrowed inter-cellular space according to both HE and PTAH profiles. Post-PRP cellular hsp72 proteins were higher by up to five percent, as measured by a gray-scale reading. Further, after a training period of 10 weeks, hsp72 mRNA expression was several times higher.

  16. Shock Analysis on a Packaged Washing Machine from Damage Boundary: Shock Response Spectrum to Component Failure

    Directory of Open Access Journals (Sweden)

    Jing Qian

    2015-01-01

    Full Text Available Both analyses of the damage boundary and shock response spectrum (RSR are the basis for the development of the protective packaging system. The shock analysis through lab test and numerical simulation found that the root cause of packaging failure was due to the stress of the critical component beyond the yield limit of the material. Lab shock test data showed that the packaging design based on the damage boundary is conservative, and the RSR could be helpful and provide support to develop more effective packaging system. Furthermore, numerical simulation can accurately analyze the component and the entire product packaging system in great detail.

  17. A second-generation constrained reaction volume shock tube.

    Science.gov (United States)

    Campbell, M F; Tulgestke, A M; Davidson, D F; Hanson, R K

    2014-05-01

    We have developed a shock tube that features a sliding gate valve in order to mechanically constrain the reactive test gas mixture to an area close to the shock tube endwall, separating it from a specially formulated non-reactive buffer gas mixture. This second-generation Constrained Reaction Volume (CRV) strategy enables near-constant-pressure shock tube test conditions for reactive experiments behind reflected shocks, thereby enabling improved modeling of the reactive flow field. Here we provide details of the design and operation of the new shock tube. In addition, we detail special buffer gas tailoring procedures, analyze the buffer/test gas interactions that occur on gate valve opening, and outline the size range of fuels that can be studied using the CRV technique in this facility. Finally, we present example low-temperature ignition delay time data to illustrate the CRV shock tube's performance.

  18. A second-generation constrained reaction volume shock tube

    Science.gov (United States)

    Campbell, M. F.; Tulgestke, A. M.; Davidson, D. F.; Hanson, R. K.

    2014-05-01

    We have developed a shock tube that features a sliding gate valve in order to mechanically constrain the reactive test gas mixture to an area close to the shock tube endwall, separating it from a specially formulated non-reactive buffer gas mixture. This second-generation Constrained Reaction Volume (CRV) strategy enables near-constant-pressure shock tube test conditions for reactive experiments behind reflected shocks, thereby enabling improved modeling of the reactive flow field. Here we provide details of the design and operation of the new shock tube. In addition, we detail special buffer gas tailoring procedures, analyze the buffer/test gas interactions that occur on gate valve opening, and outline the size range of fuels that can be studied using the CRV technique in this facility. Finally, we present example low-temperature ignition delay time data to illustrate the CRV shock tube's performance.

  19. Diffusive Shock Acceleration at Cosmological Shock Waves

    CERN Document Server

    Kang, Hyesung

    2012-01-01

    We reexamine nonlinear diffusive shock acceleration (DSA) at cosmological shocks in the large scale structure of the Universe, incorporating wave-particle interactions that are expected to operate in collisionless shocks. Adopting simple phenomenological models for magnetic field amplification (MFA) by cosmic-ray (CR) streaming instabilities and Alfv'enic drift, we perform kinetic DSA simulations for a wide range of sonic and Alfv'enic Mach numbers and evaluate the CR injection fraction and acceleration efficiency. In our DSA model the CR acceleration efficiency is determined mainly by the sonic Mach number Ms, while the MFA factor depends on the Alfv'enic Mach number and the degree of shock modification by CRs. We show that at strong CR modified shocks, if scattering centers drift with an effective Alfv'en speed in the amplified magnetic field, the CR energy spectrum is steepened and the acceleration efficiency is reduced significantly, compared to the cases without such effects. As a result, the postshock C...

  20. Grain Destruction in a Supernova Remnant Shock Wave

    Science.gov (United States)

    Raymond, John C.; Ghavamian, Parviz; Williams, Brian J.; Blair, William P.; Borkowski, Kazimierz J.; Gaetz, Terrance J.; Sankrit, Ravi

    2014-01-01

    Dust grains are sputtered away in the hot gas behind shock fronts in supernova remnants, gradually enriching the gas phase with refractory elements. We have measured emission in C IV (lambda)1550 from C atoms sputtered from dust in the gas behind a non-radiative shock wave in the northern Cygnus Loop. Overall, the intensity observed behind the shock agrees approximately with predictions from model calculations that match the Spitzer 24 micron and the X-ray intensity profiles. Thus these observations confirm the overall picture of dust destruction in SNR shocks and the sputtering rates used in models. However, there is a discrepancy in that the CIV intensity 10'' behind the shock is too high compared to the intensities at the shock and 25'' behind it. Variations in the density, hydrogen neutral fraction and the dust properties over parsec scales in the pre- shock medium limit our ability to test dust destruction models in detail.

  1. Grain Destruction in a Supernova Remnant Shock Wave

    CERN Document Server

    Raymond, John C; Williams, Brian J; Blair, William P; Borkowski, Kazimierz J; Gaetz, Terrance J; Sankrit, Ravi

    2013-01-01

    Dust grains are sputtered away in the hot gas behind shock fronts in supernova remnants, gradually enriching the gas phase with refractory elements. We have measured emission in C IV $\\lambda$1550 from C atoms sputtered from dust in the gas behind a non-radiative shock wave in the northern Cygnus Loop. Overall, the intensity observed behind the shock agrees approximately with predictions from model calculations that match the Spitzer 24 micron and the X-ray intensity profiles. Thus these observations confirm the overall picture of dust destruction in SNR shocks and the sputtering rates used in models. However, there is a discrepancy in that the CIV intensity 10" behind the shock is too high compared to the intensities at the shock and 25" behind it. Variations in the density, hydrogen neutral fraction and the dust properties over parsec scales in the pre-shock medium limit our ability to test dust destruction models in detail.

  2. Heat Shock Proteins in Tendinopathy: Novel Molecular Regulators

    Science.gov (United States)

    Millar, Neal L.; Murrell, George A. C.

    2012-01-01

    Tendon disorders—tendinopathies—are the primary reason for musculoskeletal consultation in primary care and account for up to 30% of rheumatological consultations. Whilst the molecular pathophysiology of tendinopathy remains difficult to interpret the disease process involving repetitive stress, and cellular load provides important mechanistic insight into the area of heat shock proteins which spans many disease processes in the autoimmune community. Heat shock proteins, also called damage-associated molecular patterns (DAMPs), are rapidly released following nonprogrammed cell death, are key effectors of the innate immune system, and critically restore homeostasis by promoting the reconstruction of the effected tissue. Our investigations have highlighted a key role for HSPs in tendion disease which may ultimately affect tissue rescue mechanisms in tendon pathology. This paper aims to provide an overview of the biology of heat shock proteins in soft tissue and how these mediators may be important regulators of inflammatory mediators and matrix regulation in tendinopathy. PMID:23258952

  3. Heat Shock Proteins in Tendinopathy: Novel Molecular Regulators

    Directory of Open Access Journals (Sweden)

    Neal L. Millar

    2012-01-01

    Full Text Available Tendon disorders—tendinopathies—are the primary reason for musculoskeletal consultation in primary care and account for up to 30% of rheumatological consultations. Whilst the molecular pathophysiology of tendinopathy remains difficult to interpret the disease process involving repetitive stress, and cellular load provides important mechanistic insight into the area of heat shock proteins which spans many disease processes in the autoimmune community. Heat shock proteins, also called damage-associated molecular patterns (DAMPs, are rapidly released following nonprogrammed cell death, are key effectors of the innate immune system, and critically restore homeostasis by promoting the reconstruction of the effected tissue. Our investigations have highlighted a key role for HSPs in tendion disease which may ultimately affect tissue rescue mechanisms in tendon pathology. This paper aims to provide an overview of the biology of heat shock proteins in soft tissue and how these mediators may be important regulators of inflammatory mediators and matrix regulation in tendinopathy.

  4. A feasible repetitive transcranial magnetic stimulation clinical protocol in migraine prevention

    Directory of Open Access Journals (Sweden)

    Shawn Zardouz

    2016-10-01

    Full Text Available Objective: This case series was conducted to determine the clinical feasibility of a repetitive transcranial magnetic stimulation protocol for the prevention of migraine (with and without aura. Methods: Five patients with migraines underwent five repetitive transcranial magnetic stimulation sessions separated in 1- to 2-week intervals for a period of 2 months at a single tertiary medical center. Repetitive transcranial magnetic stimulation was applied to the left motor cortex with 2000 pulses (20 trains with 1s inter-train interval delivered per session, at a frequency of 10 Hz and 80% resting motor threshold. Pre- and post-treatment numerical rating pain scales were collected, and percent reductions in intensity, frequency, and duration were generated. Results: An average decrease in 37.8%, 32.1%, and 31.2% were noted in the intensity, frequency, and duration of migraines post-repetitive transcranial magnetic stimulation, respectively. A mean decrease in 1.9±1.0 (numerical rating pain scale ± standard deviation; range: 0.4–2.8 in headache intensity scores was noted after the repetitive transcranial magnetic stimulation sessions. Conclusion: The tested repetitive transcranial magnetic stimulation protocol is a well-tolerated, safe, and effective method for migraine prevention.

  5. Final Report, Photocathodes for High Repetition Rate Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi, Ilan [Stony Brook University

    2014-04-20

    This proposal brought together teams at Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL) and Stony Brook University (SBU) to study photocathodes for high repetition rate light sources such as Free Electron Lasers (FEL) and Energy Recovery Linacs (ERL). The work done under this grant comprises a comprehensive program on critical aspects of the production of the electron beams needed for future user facilities. Our program pioneered in situ and in operando diagnostics for alkali antimonide growth. The focus is on development of photocathodes for high repetition rate Free Electron Lasers (FELs) and Energy Recovery Linacs (ERLs), including testing SRF photoguns, both normal-conducting and superconducting. Teams from BNL, LBNL and Stony Brook University (SBU) led this research, and coordinated their work over a range of topics. The work leveraged a robust infrastructure of existing facilities and the support was used for carrying out the research at these facilities. The program concentrated in three areas: a) Physics and chemistry of alkali-antimonide cathodes b) Development and testing of a diamond amplifier for photocathodes c) Tests of both cathodes in superconducting RF photoguns and copper RF photoguns

  6. Toxic Shock Syndrome (For Teens)

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Toxic Shock Syndrome KidsHealth > For Teens > Toxic Shock Syndrome Print ... it, then take some precautions. What Is Toxic Shock Syndrome? If you're a girl who's had ...

  7. Facilitating memory for novel characters by reducing neural repetition suppression in the left fusiform cortex.

    Directory of Open Access Journals (Sweden)

    Gui Xue

    Full Text Available BACKGROUND: The left midfusiform and adjacent regions have been implicated in processing and memorizing familiar words, yet its role in memorizing novel characters has not been well understood. METHODOLOGY/PRINCIPAL FINDINGS: Using functional MRI, the present study examined the hypothesis that the left midfusiform is also involved in memorizing novel characters and spaced learning could enhance the memory by enhancing the left midfusiform activity during learning. Nineteen native Chinese readers were scanned while memorizing the visual form of 120 Korean characters that were novel to the subjects. Each character was repeated four times during learning. Repetition suppression was manipulated by using two different repetition schedules: massed learning and spaced learning, pseudo-randomly mixed within the same scanning session. Under the massed learning condition, the four repetitions were consecutive (with a jittered inter-repetition interval to improve the design efficiency. Under the spaced learning condition, the four repetitions were interleaved with a minimal inter-repetition lag of 6 stimuli. Spaced learning significantly improved participants' performance during the recognition memory test administered one hour after the scan. Stronger left midfusiform and inferior temporal gyrus activities during learning (summed across four repetitions were associated with better memory of the characters, based on both within- and cross-subjects analyses. Compared to massed learning, spaced learning significantly reduced neural repetition suppression and increased the overall activities in these regions, which were associated with better memory for novel characters. CONCLUSIONS/SIGNIFICANCE: These results demonstrated a strong link between cortical activity in the left midfusiform and memory for novel characters, and thus challenge the visual word form area (VWFA hypothesis. Our results also shed light on the neural mechanisms of the spacing effect in

  8. A non-diaphragm type small shock tube for application to a molecular beam source.

    Science.gov (United States)

    Yoshimoto, Yuta; Osuka, Kenichi; Miyoshi, Nobuya; Kinefuchi, Ikuya; Takagi, Shu; Matsumoto, Yoichiro

    2013-07-01

    A non-diaphragm type small shock tube was developed for application to a molecular beam source, which can generate beams in the energy range from 1 to several electron volts and beams containing dissociated species such as atomic oxygen. Since repetitive high-frequency operation is indispensable for rapid signal acquisition in beam scattering experiments, the dimensions of the shock tube were miniaturized to reduce the evacuation time between shots. The designed shock tube is 2-4 mm in diameter and can operate at 0.5 Hz. Moreover, a high shock Mach number at the tube end is required for high-energy molecular beam generation. To reduce the shock attenuation caused by the wall boundary layer, which becomes significant in small-diameter tubes, we developed a high-speed response valve employing the current-loop mechanism. The response time of this mechanism is about 100 μs, which is shorter than the rupture time of conventional diaphragms. We show that the current-loop valve generates shock waves with shorter formation distances (about 200-300 mm) than those of conventional shock tubes. In addition, the converging geometry efficiently accelerates shock wave in the small-diameter tubes. The optimal geometry of the shock tube yields shock Mach number around 7, which indicates that the translation energy of molecular beams can exceed 1 eV even in the presence of the real gas effect.

  9. Climate shocks and conflict

    NARCIS (Netherlands)

    Papaioannou, Kostadis J.

    2016-01-01

    This paper offers a historical micro-level analysis of the impact of climate shocks on the incidence of civil conflict in colonial Nigeria (1912-1945). Primary historical sources on court cases, prisoners and homicides are used to capture conflict. To measure climate shocks we use the deviation f

  10. [Historical vision of shock].

    Science.gov (United States)

    Dosne Pasqualini, C

    1998-01-01

    The concept of shock and its close relationship with that of stress dates back to the experiments of Hans Selye initiated in 1936 at McGill University in Montreal, with whom I collaborated between 1939 and 1942. It was demonstrated that the General Adaptation Syndrome begins with an Alarm Reaction, which consists of a Stage of Shock and one of Counter-Shock, followed by a Stage of Adaptation and finally a Stage of Exhaustion. My Ph.D. thesis concluded that shock was due to an adrenal insufficiency postulating that active metabolic processes drain the body of certain essential compounds the lack of which causes shock. My interest in the role of the glucose metabolism in shock led me to work with Bernardo Houssay in 1942 at the Institute of Physiology of the University of Buenos Aires and in 1944 with C.N.H. Long at Yale University. There I developed a method for the induction of hemorrhagic shock in the guinea pig with 94% lethality; curiously, the administration of 200 mg of ascorbic acid prevented death. Upon my return to Buenos Aires, these results were confirmed and moreover, it was demonstrated that the administration of cortisone led to 40% survival of the animals while desoxycorticosterone had no effect. At the time, no explanation was available but to-day, half a century later, this Symposium should be able to explain the mechanisms leading to death by hemorrhagic shock.

  11. [Shock waves in orthopedics].

    Science.gov (United States)

    Haupt, G

    1997-05-01

    Extracorporeal shock waves have revolutionized urological stone treatment. Nowadays shock waves are widely used in orthopedics, too. This article reviews the applications of extracorporeal shock waves on bone and adjacent soft tissue. The osteoneogenetic effect of extracorporeal shock waves has been proven and can be used to treat pseudarthrosis with a success rate of around 75%. Shock waves have a positive effect in tennis and golfer's elbow, calcaneal spur, and the complex called "periarthritis humero-scapularis." The mechanism for this is not yet known, and results from large prospective and randomized studies are still lacking. However, the treatment has been performed many thousands of times. In patients in whom conservative treatment has failed surgery used to be the only choice, but its success rate barely exceeds that of shock wave therapy and surgery can still be done if shock wave therapy fails. Extracorporeal shock waves will have an impact on orthopedics comparable to its effect in urology. Scientific evaluations, professional certifications, quality assurance and reimbursement issues present great challenges.

  12. The Shock Routine

    DEFF Research Database (Denmark)

    van Hooren, Franca; Kaasch, Alexandra; Starke, Peter

    2014-01-01

    in Australia, Belgium, the Netherlands and Sweden over the course of four global economic shocks, we ask whether the notion of critical junctures is useful in understanding the nature of change triggered by crisis. The main empirical finding is that fundamental change in the aftermath of an exogenous shock...

  13. Our Favorite Film Shocks

    DEFF Research Database (Denmark)

    Willerslev, Rane; Suhr, Christian

    2014-01-01

    shocks? In this text we exchange personal experiences of cinematic shocks and ponder over these questions as related to wider theories on human trauma, emancipation, and enlightenment. In conclusion we argue for a revision of anthropological notions of validity in terms of the efficacy of the cinematic...

  14. Shock Tube as an Impulsive Application Device

    Directory of Open Access Journals (Sweden)

    Soumya Ranjan Nanda

    2017-01-01

    Full Text Available Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

  15. Reflection of curved shock waves

    Science.gov (United States)

    Mölder, S.

    2017-03-01

    Shock curvatures are related to pressure gradients, streamline curvatures and vorticity in flows with planar and axial symmetry. Explicit expressions, in an influence coefficient format, are used to relate post-shock pressure gradient, streamline curvature and vorticity to pre-shock gradients and shock curvature in steady flow. Using higher order, von Neumann-type, compatibility conditions, curved shock theory is applied to calculate the flow near singly and doubly curved shocks on curved surfaces, in regular shock reflection and in Mach reflection. Theoretical curved shock shapes are in good agreement with computational fluid dynamics calculations and experiment.

  16. Reflection of curved shock waves

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Shock curvatures are related to pressure gradients, streamline curvatures and vorticity in flows with planar and axial symmetry. Explicit expressions, in an influence coefficient format, are used to relate post-shock pressure gradient, streamline curvature and vorticity to pre-shock gradients and shock curvature in steady flow. Using higher order, von Neumann-type, compatibility conditions, curved shock theory is applied to calculate the flow near singly and doubly curved shocks on curved surfaces, in regular shock reflection and in Mach reflection. Theoretical curved shock shapes are in good agreement with computational fluid dynamics calculations and experiment.

  17. Diffusive Shock Acceleration the Fermi Mechanism

    CERN Document Server

    Baring, M G

    1997-01-01

    The mechanism of diffusive Fermi acceleration at collisionless plasma shock waves is widely invoked in astrophysics to explain the appearance of non-thermal particle populations in a variety of environments, including sites of cosmic ray production, and is observed to operate at several sites in the heliosphere. This review outlines the principal results from the theory of diffusive shock acceleration, focusing first on how it produces power-law distributions in test-particle regimes, where the shock dynamics are dominated by the thermal populations that provide the seed particles for the acceleration process. Then the importance of non-linear modifications to the shock hydrodynamics by the accelerated particles is addressed, emphasizing how these subsequently influence non-thermal spectral formation.

  18. Experimental Investigation of Shock Wave Surfing

    CERN Document Server

    Parziale, N J; Hornung, H G; Shepherd, J E

    2010-01-01

    Shock wave surfing is investigated experimentally in GALCIT's Mach 4.0 Ludwieg Tube. Shock wave surfing occurs when a secondary free-body follows the bow shock formed by a primary free-body; an example of shock wave surfing occurs during meteorite breakup. The free-bodies in the current investigation are nylon spheres. During each run in the Ludwieg tube a high speed camera is used to capture a series of schlieren images; edge tracking software is used to measure the position of each sphere. Velocity and acceleration are had from processing the position data. The radius ratio and initial orientation of the two spheres are varied in the test matrix. The variation of sphere radius ratio and initial angle between the centers of gravity are shown to have a significant effect on the dynamics of the system.

  19. Shock acceleration in partially neutral plasmas

    CERN Document Server

    Morlino, G; Blasi, P; Caprioli, D

    2010-01-01

    We present the non-linear theory of shock acceleration applied to SNRs expanding into partially neutral plasma. Using this theory we show how the Balmer lines detected from young SNRs can be used to test the efficiency of shocks in the production of cosmic rays. In particular we investigate the effect of charge-exchange between protons and neutral hydrogen occurring in the precursor formed ahead of the shock. In this precursor the CR pressure accelerate the ionized component of the plasma and a relative velocity between protons and neutral hydrogen is established. On the other hand the charge-exchange process tends to equilibrate ions and neutrals resulting in the heating of both components. We show that even when the shock converts only a few per cent of the total bulk kinetic energy into CRs, the heating is efficient enough to produce a detectable broadening of the narrow Balmer lines emitted by the neutral hydrogen.

  20. Robust Repetitive Controller for Fast AFM Imaging

    CERN Document Server

    Necipoglu, Serkan; Has, Yunus; Guvenc, Levent; Basdogan, Cagatay

    2012-01-01

    Currently, Atomic Force Microscopy (AFM) is the most preferred Scanning Probe Microscopy (SPM) method due to its numerous advantages. However, increasing the scanning speed and reducing the interaction forces between the probe's tip and the sample surface are still the two main challenges in AFM. To meet these challenges, we take advantage of the fact that the lateral movements performed during an AFM scan is a repetitive motion and propose a Repetitive Controller (RC) for the z-axis movements of the piezo-scanner. The RC utilizes the profile of the previous scan line while scanning the current line to achieve a better scan performance. The results of the scanning experiments performed with our AFM set-up show that the proposed RC significantly outperforms a conventional PI controller that is typically used for the same task. The scan error and the average tapping forces are reduced by 66% and 58%, respectively when the scan speed is increased by 7-fold.

  1. Verbal behavior in Alzheimer disease patients: Analysis of phrase repetition

    Directory of Open Access Journals (Sweden)

    Juliana Francisca Cecato

    Full Text Available Abstract Language problems in the elderly with AD are due to the fact that deterioration occurs not only in semantic memory, but in a group of cognitive factors, evidenced by a deficiency in search strategies for linguistic information. Objectives: To evaluate phrase repetition in two cognitive tests, the MMSE and MoCA, in a group of Alzheimer disease patients (AD and normal controls. Methods: A Cross-sectional study was conducted involving 20 patients who sought medical assistance at a geriatric institute in Jundiaí, São Paulo. The subjects underwent a detailed clinical examination and neuropsychometric evaluation. All subjects with AD met DSM-IV and NINCDS-ADRDA criteria. Ten patients received a diagnosis of AD and 10 were healthy subjects, forming the control group (CG. Results: All participants correctly answered the phrase from the MMSE (phrase 1. The MoCA phrases (phrases 2 and 3 were correct in 80% and 90%, respectively in the CG and in 40% and 50%, respectively in the AD group. Conclusions: The MoCA test proved more effective in evaluating the echoic behavior in AD patients compared to the MMSE. The simpler phrase repetition task in the MMSE was found to be less sensitive in detecting mild language decline in AD patients.

  2. A repetitive elements perspective in Polycomb epigenetics.

    Directory of Open Access Journals (Sweden)

    Valentina eCasa

    2012-10-01

    Full Text Available Repetitive elements comprise over two-thirds of the human genome. For a long time, these elements have received little attention since they were considered non functional. On the contrary, recent evidence indicates that they play central roles in genome integrity, gene expression and disease. Indeed, repeats display meiotic instability associated with disease and are located within common fragile sites, which are hotspots of chromosome rearrangements in tumors. Moreover, a variety of diseases have been associated with aberrant transcription of repetitive elements. Overall this indicates that appropriate regulation of repetitive elements’ activity is fundamental.Polycomb group (PcG proteins are epigenetic regulators that are essential for the normal development of multicellular organisms. Mammalian PcG proteins are involved in fundamental processes, such as cellular memory, cell proliferation, genomic imprinting, X-inactivation, and cancer development. PcG proteins can convey their activity through long-distance interactions also on different chromosomes. This indicates that the 3D organization of PcG proteins contributes significantly to their function. However, it is still unclear how these complex mechanisms are orchestrated and which role PcG proteins play in the multi-level organization of gene regulation. Intriguingly, the greatest proportion of Polycomb-mediated chromatin modifications is located in genomic repeats and it has been suggested that they could provide a binding platform for Polycomb proteins.Here, these lines of evidence are woven together to discuss how repetitive elements could contribute to chromatin organization in the 3D nuclear space.

  3. The Rhythms of Echo. Variations on Repetition

    Directory of Open Access Journals (Sweden)

    Rosa María Aradra Sánchez

    2015-04-01

    Full Text Available This paper presents a study on the echo as metric and rhetorical procedure. It makes a brief tour through some of the poetic manifestations of echo in the Spanish literary tradition, and a brief tour through the attention that metric theory has paid to this phenomenon. Then it stops at the possibilities that rhetoric offers for its analysis from the generic approach of the discursive repetition phenomena.

  4. Repetitive behaviour in autism: Imaging pathways and trajectories

    NARCIS (Netherlands)

    Langen, M.J.G.

    2009-01-01

    Repetitive behaviour in autism: Imaging pathways and trajectories Repetitive and rigid behaviour is one of the core symptoms of autism, a severe and lifelong child psychiatric disorder. Although repetitive behaviour symptoms often form a significant impairment for affected individuals, systematic st

  5. Neural Correlates of Restricted, Repetitive Behaviors in Autism Spectrum Disorders

    Science.gov (United States)

    2014-12-01

    Restrictive Repetitive Behaviors in Autism Spectrum Disorder . Authors: T.Q.Nguyen, B...Manoach. Functional Connectivity of the Dorsal Anterior Cingulate Cortex Predicts Restrictive Repetitive Behaviors in Autism Spectrum Disorder We...Introduction: Although restricted , repetitive behaviors (RRBs) are a highly disabling core feature of Autism Spectrum Disorders (ASDs), they

  6. Lingual Kinematics during Rapid Syllable Repetition in Parkinson's Disease

    Science.gov (United States)

    Wong, Min Ney; Murdoch, Bruce E.; Whelan, Brooke-Mai

    2012-01-01

    Background: Rapid syllable repetition tasks are commonly used in the assessment of motor speech disorders. However, little is known about the articulatory kinematics during rapid syllable repetition in individuals with Parkinson's disease (PD). Aims: To investigate and compare lingual kinematics during rapid syllable repetition in dysarthric…

  7. Repetitive Elements in Mycoplasma hyopneumoniae Transcriptional Regulation

    Science.gov (United States)

    Cattani, Amanda Malvessi; Siqueira, Franciele Maboni; Guedes, Rafael Lucas Muniz; Schrank, Irene Silveira

    2016-01-01

    Transcriptional regulation, a multiple-step process, is still poorly understood in the important pig pathogen Mycoplasma hyopneumoniae. Basic motifs like promoters and terminators have already been described, but no other cis-regulatory elements have been found. DNA repeat sequences have been shown to be an interesting potential source of cis-regulatory elements. In this work, a genome-wide search for tandem and palindromic repetitive elements was performed in the intergenic regions of all coding sequences from M. hyopneumoniae strain 7448. Computational analysis demonstrated the presence of 144 tandem repeats and 1,171 palindromic elements. The DNA repeat sequences were distributed within the 5’ upstream regions of 86% of transcriptional units of M. hyopneumoniae strain 7448. Comparative analysis between distinct repetitive sequences found in related mycoplasma genomes demonstrated different percentages of conservation among pathogenic and nonpathogenic strains. qPCR assays revealed differential expression among genes showing variable numbers of repetitive elements. In addition, repeats found in 206 genes already described to be differentially regulated under different culture conditions of M. hyopneumoniae strain 232 showed almost 80% conservation in relation to M. hyopneumoniae strain 7448 repeats. Altogether, these findings suggest a potential regulatory role of tandem and palindromic DNA repeats in the M. hyopneumoniae transcriptional profile. PMID:28005945

  8. Modeling repetitive motions using structured light.

    Science.gov (United States)

    Xu, Yi; Aliaga, Daniel G

    2010-01-01

    Obtaining models of dynamic 3D objects is an important part of content generation for computer graphics. Numerous methods have been extended from static scenarios to model dynamic scenes. If the states or poses of the dynamic object repeat often during a sequence (but not necessarily periodically), we call such a repetitive motion. There are many objects, such as toys, machines, and humans, undergoing repetitive motions. Our key observation is that when a motion-state repeats, we can sample the scene under the same motion state again but using a different set of parameters; thus, providing more information of each motion state. This enables robustly acquiring dense 3D information difficult for objects with repetitive motions using only simple hardware. After the motion sequence, we group temporally disjoint observations of the same motion state together and produce a smooth space-time reconstruction of the scene. Effectively, the dynamic scene modeling problem is converted to a series of static scene reconstructions, which are easier to tackle. The varying sampling parameters can be, for example, structured-light patterns, illumination directions, and viewpoints resulting in different modeling techniques. Based on this observation, we present an image-based motion-state framework and demonstrate our paradigm using either a synchronized or an unsynchronized structured-light acquisition method.

  9. FRB repetition and non-Poissonian statistics

    CERN Document Server

    Connor, Liam; Oppermann, Niels

    2016-01-01

    We discuss some of the claims that have been made regarding the statistics of fast radio bursts (FRBs). In an earlier paper \\citep{2015arXiv150505535C} we conjectured that flicker noise associated with FRB repetition could show up in non-cataclysmic neutron star emission models, like supergiant pulses. We show how the current limits of repetition would be significantly weakened if their repeat rate really were non-Poissonian and had a pink or red spectrum. Repetition and its statistics have implications for observing strategy, generally favouring shallow wide-field surveys, since in the non-repeating scenario survey depth is unimportant. We also discuss the statistics of the apparent latitudinal dependence of FRBs, and offer a simple method for calculating the significance of this effect. We provide a generalized Bayesian framework for addressing this problem, which allows for direct model comparison. It is shown how the evidence for a steep latitudinal gradient of the FRB rate is less strong than initially s...

  10. INVESTIGATION ON NONEQULIBRIUM RADIATION AND RELAXATION PHENOMENA IN SHOCK TUBES

    Institute of Scientific and Technical Information of China (English)

    竺乃宜; 杨乾锁; 张恒利; 余西龙; 黄立舜

    2003-01-01

    The experimental results for the excited time of the nonequlibrium radiation andthe ionization behind strong shock waves are presented. Using an optical multichannel analyzer, InSb infrared detectors and near-free-molecular Langmuir probes, the infrared radiation, the electron density of air and the nonequlibrium radiation spectra at different moments of the relaxation process in nitrogen test gas behind normal shock waves were obtained, respectively, in hydrogen oxygen combustion driven shock tubes.

  11. Scaling for Shock Response of Equipment in Different Submarines

    OpenAIRE

    O’Hara, G.J.; Cunniff, P.F.

    1993-01-01

    This article presents scaling rules developed to predict the response of submarine equipment subjected to underwater chemical explosions. The computer was used as a surrogate for shock tests. A simplified model of a hull section was used to contain frame-mounted single degree of freedom equipment. A general scaling rule has been developed to handle the spread in the shock response attributable to the charge weight, equipment weight, and equipment frequency, where the shock response is the abs...

  12. Vasogenic shock physiology

    Directory of Open Access Journals (Sweden)

    Sotiria Gkisioti

    2011-01-01

    Full Text Available Sotiria Gkisioti, Spyros D MentzelopoulosDepartment of Intensive Care Medicine, University of Athens Medical School, Evaggelismos General Hospital, Athens, GreeceAbstract: Shock means inadequate tissue perfusion by oxygen-carrying blood. In vasogenic shock, this circulatory failure results from vasodilation and/or vasoplegia. There is vascular hyporeactivity with reduced vascular smooth muscle contraction in response to α1 adrenergic agonists. Considering vasogenic shock, one can understand its utmost importance, not only because of its association with sepsis but also because it can be the common final pathway for long-lasting, severe shock of any cause, even postresuscitation states. The effective management of any patient in shock requires the understanding of its underlying physiology and pathophysiology. Recent studies have provided new insights into vascular physiology by revealing the interaction of rather complicated and multifactorial mechanisms, which have not been fully elucidated yet. Some of these mechanisms, such as the induction of nitric oxide synthases, the activation of adenosine triphosphate-sensitive potassium channels, and vasopressin deficiency, have gained general acceptance and are considered to play an important role in the pathogenesis of vasodilatory shock. The purpose of this review is to provide an update on the pathogenesis of vasogenic shock.Keywords: nitric oxide synthases, KATP channels, vasopressin, H2S, vasoplegic syndrome

  13. Numerical Simulation of Shock and Vibration Tests for Converter Cabinet%变流器柜体冲击和随机振动试验的数值模拟

    Institute of Scientific and Technical Information of China (English)

    丁杰; 忻力; 荣智林; 陈燕平

    2012-01-01

    According to the standard GB/T 21563-2008 'Railway applications- Rolling stock equipment- Shock and vibration tests', the responses of the structure under random loading were computed by the finite-element analysis software ANSYS. From the results, the maximum of the 1σ 2σ and 3σ Von Mises stress was obtained. Utilizing the S-N curve of the materials, and according to Steinberg's Gaussian distribution of responses under random loading and Miner's linear fatigue accumulation rule, the life prediction of the structure under random loading was carried out. The transient dynamics analysis was also performed for shock tests.%根据标准GB/T 21563-2008《轨道交通机车车辆设备冲击和振动试验》,采用ANSYS有限元分析软件计算了随机振动环境下的响应,得到了结构的1σ、2σ、3σVonMises最大应力.利用材料的S-N曲线,并根据Steinberg提出结构在随机载荷作用下的响应是基于高斯分布和Miner提出的线性疲劳累计损伤理论,对设计的结构在给定随机振动环境下的疲劳寿命进行了预估.运用瞬态动力学分析方法模拟了冲击试验过程中的受力情况.

  14. Effects of inspiratory muscle training upon recovery time during high intensity, repetitive sprint activity.

    Science.gov (United States)

    Romer, L M; McConnell, A K; Jones, D A

    2002-07-01

    The present study examined the influence of specific inspiratory muscle training (IMT) upon recovery time during repetitive sprint activity, as well as the physiological and perceptual responses to fixed intensity shuttle running. Using a double-blind placebo-controlled design, 24 male repetitive sprint athletes were assigned randomly to either an IMT (n = 12) or placebo (n = 12) group. The self-selected recovery time during a repetitive sprint test and the physiological response to submaximal endurance exercise were determined. Following completion of baseline and pre-intervention measures, the IMT group performed 30 inspiratory efforts twice daily against a resistance equivalent to 50 % maximum inspiratory mouth pressure (MIP) for 6 wk. The placebo group performed 60 breaths once daily, for 6 wk, at a resistance equivalent to 15 % MIP, a load known to elicit negligible changes in respiratory muscle function. The IMT group improved total recovery time during the repetitive sprint test by 6.2 +/- 1.1 % (mean +/- SEM) above the changes noted for the placebo group (p = 0.006). Blood lactate and perceptual responses to submaximal exercise were also significantly attenuated following IMT (p attenuates the blood lactate and perceptual responses to submaximal endurance exercise. In addition, the present study provides new evidence that IMT improves recovery time during high intensity, intermittent exercise in repetitive sprint athletes.

  15. 多巴酚丁胺应激试验对感染性休克患者的预后评价%Prognostic value of dobutamine stress test in patients with septic shock

    Institute of Scientific and Technical Information of China (English)

    邱海波; 杨毅; 周韶霞; 刘少华; 郑瑞强

    2001-01-01

    目的:观察多巴酚丁胺应激试验对感染性休克患者的预后价值.方法:感染性休克患者静脉持续滴注多巴酚丁胺10μg·kg-1·min-1 h,观察患者全身血流动力学和氧代谢的改变,氧耗量(VO2)增加15%以上者为试验阳性.结果:47例感染性休克患者中,21例应激试验阳性,26例阴性.阳性组应用多巴酚丁胺后心指数(CI)增加18.1%,氧输送增加12.7%,VO2增加37.6%,氧摄取率增加18.0%,体血管阻力指数降低18.5%.阴性组CI增加11.5%,氧输送、VO2和氧摄取率均无明显改变.阴性组患者病死率76.9%,阳性组为33.3%(P<0.05).结论:多巴酚丁胺应激试验可作为感染性休克患者预后评估的动态指标.%AIM: To evaluate the prognostic effect of dobutamine stress test in patients with septic shock. METHODS: Patients with septic shock received intravenous infusion of dobutamine at 10 μg·kg-1·min-1 for 1 h. Hemodynamics and oxygen metabolism was observed. A patient who was able to increase oxygen consumption index (Vo2) by>15% was designated as a responder to the test. RESULTS: In 47 patients with septic shock, twenty one responders and twenty six nonresponders were identified, and mortality was 33.3% and 76.9% respectively. After the dobutamine infusion, the responders showed increases in cardiac index (18.1%), oxygen delivery index (12.7%), Vo2 (38.6%), and oxygen extraction ratio (18.0%), and reductions in systemic vascular resistance index (18.5%). The nonresponders demonstrated increases in cardiac index (11.5%), but no change in oxygen delivery, Vo2, and oxygen extraction ratio. CONCLUSION: Dobutamine stress test might be a good predictor of outcome in patients with septic shock.

  16. Proton Acceleration at Oblique Shocks

    Science.gov (United States)

    Galinsky, V. L.; Shevchenko, V. I.

    2011-06-01

    Acceleration at the shock waves propagating oblique to the magnetic field is studied using a recently developed theoretical/numerical model. The model assumes that resonant hydromagnetic wave-particle interaction is the most important physical mechanism relevant to motion and acceleration of particles as well as to excitation and damping of waves. The treatment of plasma and waves is self-consistent and time dependent. The model uses conservation laws and resonance conditions to find where waves will be generated or damped, and hence particles will be pitch-angle-scattered. The total distribution is included in the model and neither introduction of separate population of seed particles nor some ad hoc escape rate of accelerated particles is needed. Results of the study show agreement with diffusive shock acceleration models in the prediction of power spectra for accelerated particles in the upstream region. However, they also reveal the presence of spectral break in the high-energy part of the spectra. The role of the second-order Fermi-like acceleration at the initial stage of the acceleration is discussed. The test case used in the paper is based on ISEE-3 data collected for the shock of 1978 November 12.

  17. Non-haemorrhagic obstetric shock.

    Science.gov (United States)

    Thomson, A J; Greer, I A

    2000-02-01

    The causes of non-haemorrhagic obstetric shock (pulmonary thromboembolism, amniotic fluid embolism, acute uterine inversion and sepsis) are uncommon but responsible for the majority of maternal deaths in the developed world. Clinically suspected pulmonary thromboembolism should be treated initially with heparin and objective testing should be performed. If the diagnosis is confirmed, heparin is usually continued until delivery, following which anticoagulation in the puerperium is achieved with either warfarin or heparin. Amniotic fluid embolism is a rare complication of pregnancy, occurring most commonly during labour. The management of amniotic fluid embolism involves maternal oxygenation, the maintenance of cardiac output and blood pressure, and the management of any associated coagulopathy. Acute uterine inversion arises most commonly following mismanagement of the third stage of labour. The shock in uterine inversion is neurogenic in origin, although there may also be profound haemorrhage. The management of this condition includes maternal resuscitation and replacement of the uterus either manually, surgically or by hydrostatic pressure. Genital tract sepsis remains a significant cause of maternal death, the most common predisposing factor being prolonged rupture of the fetal membranes. The management of septic shock in pregnancy includes resuscitation, identification of the source of infection and alteration of the systemic inflammatory response.

  18. Diagnosis and management of shock in the emergency department.

    Science.gov (United States)

    Richards, Jeremy B; Wilcox, Susan R

    2014-03-01

    Shock is a state of acute circulatory failure leading to decreased organ perfusion, with inadequate delivery of oxygenated blood to tissues and resultant end-organ dysfunction. The mechanisms that can result in shock are divided into 4 categories: (1) hypovolemic, (2) distributive, (3) cardiogenic, and (4) obstructive. While much is known regarding treatment of patients in shock, several controversies continue in the literature. Assessment begins with identifying the need for critical interventions such as intubation, mechanical ventilation, or obtaining vascular access. Prompt workup should be initiated with laboratory testing (especially of serum lactate levels) and imaging, as indicated. Determining the intravascular volume status of patients in shock is critical and aids in categorizing and informing treatment decisions. This issue reviews the 4 primary categories of shock as well as special categories, including shock in pregnancy, traumatic shock, septic shock, and cardiogenic shock in myocardial infarction. Adherence to evidence-based care of the specific causes of shock can optimize a patient's chances of surviving this life-threatening condition.

  19. FEA for designing of floating raft shock-resistant system

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ying-long; HE Lin; HUANG Ying-yun; WANG Yu

    2003-01-01

    Choosing the equipment with good shock-resistant performance and taking shock protection measures while designing the onboard settings, the safety of onboard settings can be assured when warships, especially submarine subjected to non-contact underwater explosion, that is, these means can be used to limit the rattlespace (i.e., the maximum displacement of the equipment relative to the base) and the peak acceleration experienced by the equipment. Using shock-resistant equipments is one of shock protection means. The shock-resistant performance of the shock-resistant equipments should be verified in the design phase of the equipments. The FEA (finite element analysis) software, for example, MSC.NASTRAN(R), can be used to verify the shock-resistant performance. MSC.PATRAN(R) and MSC.NASTRAN are used for modeling and analyzing the floating raft vibration isolating equipment. The model of the floating raft and the floating raft vibration isolating system are theoretically analyzed and calculated, and the analysis results are in agreement with the test results. The transient response analysis of the system model follows the modal analysis of the floating raft vibration isolating system. And it is used to verify the shock-resistant performance. The analysis and calculation method used in this paper can be used to analyze the shock-resistant performance of onboard shock-resistant equipments.

  20. fMRI repetition suppression: neuronal adaptation or stimulus expectation?

    Science.gov (United States)

    Larsson, Jonas; Smith, Andrew T

    2012-03-01

    Measurements of repetition suppression with functional magnetic resonance imaging (fMRI adaptation) have been used widely to probe neuronal population response properties in human cerebral cortex. fMRI adaptation techniques assume that fMRI repetition suppression reflects neuronal adaptation, an assumption that has been challenged on the basis of evidence that repetition-related response changes may reflect unrelated factors, such as attention and stimulus expectation. Specifically, Summerfield et al. (Summerfield C, Trittschuh EH, Monti JM, Mesulam MM, Egner T. 2008. Neural repetition suppression reflects fulfilled perceptual expectations. Nat Neurosci. 11:1004-1006) reported that the relative frequency of stimulus repetitions and non-repetitions influenced the magnitude of repetition suppression in the fusiform face area, suggesting that stimulus expectation accounted for most of the effect of repetition. We confirm that stimulus expectation can significantly influence fMRI repetition suppression throughout visual cortex and show that it occurs with long as well as short adaptation durations. However, the effect was attention dependent: When attention was diverted away from the stimuli, the effects of stimulus expectation completely disappeared. Nonetheless, robust and significant repetition suppression was still evident. These results suggest that fMRI repetition suppression reflects a combination of neuronal adaptation and attention-dependent expectation effects that can be experimentally dissociated. This implies that with an appropriate experimental design, fMRI adaptation can provide valid measures of neuronal adaptation and hence response specificity.

  1. Collisionless parallel shocks

    Science.gov (United States)

    Khabibrakhmanov, I. KH.; Galeev, A. A.; Galinskii, V. L.

    1993-01-01

    Consideration is given to a collisionless parallel shock based on solitary-type solutions of the modified derivative nonlinear Schroedinger equation (MDNLS) for parallel Alfven waves. The standard derivative nonlinear Schroedinger equation is generalized in order to include the possible anisotropy of the plasma distribution and higher-order Korteweg-de Vies-type dispersion. Stationary solutions of MDNLS are discussed. The anisotropic nature of 'adiabatic' reflections leads to the asymmetric particle distribution in the upstream as well as in the downstream regions of the shock. As a result, nonzero heat flux appears near the front of the shock. It is shown that this causes the stochastic behavior of the nonlinear waves, which can significantly contribute to the shock thermalization.

  2. Shock structures of astrospheres

    CERN Document Server

    Scherer, Klaus; Kleimann, Jens; Wiengarten, Tobias; Bomans, Dominik J; Weis, Kerstin

    2015-01-01

    The interaction between a supersonic stellar wind and a (super-)sonic interstellar wind has recently been viewed with new interest. We here first give an overview of the modeling, which includes the heliosphere as an example of a special astrosphere. Then we concentrate on the shock structures of fluid models, especially of hydrodynamic (HD) models. More involved models taking into account radiation transfer and magnetic fields are briefly sketched. Even the relatively simple HD models show a rich shock structure, which might be observable in some objects. We employ a single fluid model to study these complex shock structures, and compare the results obtained including heating and cooling with results obtained without these effects. Furthermore, we show that in the hypersonic case valuable information of the shock structure can be obtained from the Rankine-Hugoniot equations. We solved the Euler equations for the single fluid case and also for a case including cooling and heating. We also discuss the analytic...

  3. Counseling For Future Shock

    Science.gov (United States)

    Morgan, Lewis B.

    1974-01-01

    In this article the author looks at some of the searing prophecies made by Alvin Toffler in his book Future Shock and relates them to the world of the professional counselor and the clientele the counselor attempts to serve. (Author)

  4. Index to the Shock and Vibration Bulletins

    Science.gov (United States)

    1968-02-01

    facilities Reynold’s number graph, 26-2-172 supercritical in study of flow of incompressi- ble fluids, 26-2-147 vortex discharge at, 26-2-147, 180...used in shipboard shock tests, 29-1-12 Velocity generators, waterjet actuators, for sled tests, 35-6-47 Vermiculite, shock mitigating character...towers and other struc- tures, 34-2-279 at supercritical Reynolds number, 26-2-147,180 Vulnerability of aircraft to blast, 28-1-56 to nuclear

  5. The development of a repetition-load scheme for the eccentric-only bench press exercise.

    Science.gov (United States)

    Moir, Gavin L; Erny, Kyle F; Davis, Shala E; Guers, John J; Witmer, Chad A

    2013-01-01

    The purpose of the present study was to develop a repetition-load scheme for the eccentric-only bench press exercise. Nine resistance trained men (age: 21.6 ± 1.0 years; 1-repetition maximum [RM] bench press: 137.7 ± 30.4 kg) attended four testing sessions during a four week period. During the first session each subject's 1-RM bench press load utilizing the stretch-shortening cycle was determined. During the remaining sessions they performed eccentric-only repetitions to failure using supra-maximal loads equivalent to 110%, 120% and 130% of their 1-RM value with a constant cadence (30 reps·min(-1)). Force plates and a three dimensional motion analysis system were used during these final three sessions in order to evaluate kinematic and kinetic variables. More repetitions were completed during the 110% 1-RM condition compared to the 130% 1-RM condition (p=0.01). Mean total work (p=0.046) as well as vertical force (p=0.049), vertical work (p=0.017), and vertical power output (p=0.05) were significantly greater during the 130% 1-RM condition compared to the 110% 1-RM condition. A linear function was fitted to the number of repetitions completed under each load condition that allowed the determination of the maximum number of repetitions that could be completed under other supra-maximal loads. This linear function predicted an eccentric-only 1-RM in the bench press with a load equivalent to 164.8% 1-RM, producing a load of 227.0 ± 50.0 kg. The repetition-load scheme presented here should provide a starting point for researchers to investigate the kinematic, kinetic and metabolic responses to eccentric-only bench press workouts.

  6. 100 kV/2A three-phase constant-current repetitive-rate charging equipment

    CERN Document Server

    Tan Yu Gang; Chen Li Dong; Guo Zhi Gang; Zou Xiao Bing; Luo Min; Cao Shao Yun; Chang An Bi

    2002-01-01

    A 100 kV/2A three-phase constant-current repetitive-rate charging equipment was designed and constructed. A three-phase L-C converter is adopted as constant-current power source. Six Insulated Gate Bipolar Transistors (IGBTs) are connected in parallel to control the stop of charge. A Programmable Logical Controller (PLC) is the central element of the control unit. The equipment is used in the repetitive-rate discharge features test of the switch. It works stably under the conditions of 2A charging current, 10 Hz operating voltage, 100 kV repetitive rate and 1 mu F capacitor

  7. The effects of high resistance-few repetitions and low resistance-high repetitions resistance training on climbing performance.

    Science.gov (United States)

    Hermans, Espen; Andersen, Vidar; Saeterbakken, Atle Hole

    2017-05-01

    The aim of the study was to compare the effects of different strength training intensities on climbing performance, climbing-specific tests and a general strength test. Thirty lower grade and intermediate-level climbers participated in a 10-week training programme. The participants were randomized into three groups: high resistance-few repetitions training groups (HR-FR), low resistance-high repetitions training groups (LR-HR) and a control group (CON) which continued climbing/training as usual. Post-testing results demonstrated statistical tendencies for climbing performance improvements in the HR-FR and LR-HR (p = 0.088-0.090, effect size = 0.55-0.73), but no differences were observed between the groups (p = 0.950). For the climbing-specific tests, no differences were observed between the groups (p = 0.507-1.000), but the HR-FR and LR-HR improved their time in both Dead-hang (p = 0.004-0.026) and Bent-arm hang (p training groups reduced their climbing sessions during the intervention compared to the CON group (p = 0.057-0.074). In conclusion, HR-FR and LR-HR training programmes demonstrated an 11% and 12% non-significant improvement in climbing performance despite a 50% reduction in climbing sessions, but improved the results in strength and climbing-specific tests. None of the training intensities was superior compared to the others.

  8. Measurement of Naval Ship Responses to Underwater Explosion Shock Loadings

    Directory of Open Access Journals (Sweden)

    Il-Kwon Park

    2003-01-01

    Full Text Available The shock-resistance capability of battle ships against a non-contact underwater explosion (UNDEX is a very critical factor of survivability. In July 1987 and April 2000, we successfully conducted UNDEX shock tests for a coastal mine hunter (MHC and a mine sweeper/hunter (MSH of Republic of Korea Navy (ROKN, at the Chinhae bay, Korea. Test planning for conducting these shock tests included responsibilities, methods, and procedures. Test instruments were developed and tested on a drop shock machine to confirm availability in the actual shock tests with emphasis on shock resistance, remote control and reliability. All vital systems of the ships were confirmed to be capable of normal operational condition without significant damages during the explosion shot. By analyzing the test results, the tactical operational safety zone of the ships in underwater explosion environments was estimated. In this paper, we described the results of measurement of naval ship responses to underwater explosion shock loadings including test planning, sensor locations, data reduction, explosive devices, instrumentation and damage assessments of MSH.

  9. [Pathophysiology of hemorragic shock].

    Science.gov (United States)

    Copotoiu, R; Cinca, E; Collange, O; Levy, F; Mertes, P-M

    2016-11-01

    This review addresses the pathophysiology of hemorrhagic shock, a condition produced by rapid and significant loss of intravascular volume, which may lead to hemodynamic instability, decreases in oxygen delivery, decreased tissue perfusion, cellular hypoxia, organ damage, and death. The initial neuroendocrine response is mainly a sympathetic activation. Haemorrhagic shock is associated altered microcirculatory permeability and visceral injury. It is also responsible for a complex inflammatory response associated with hemostasis alteration. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Note: A table-top blast driven shock tube.

    Science.gov (United States)

    Courtney, Michael W; Courtney, Amy C

    2010-12-01

    The prevalence of blast-induced traumatic brain injury in conflicts in Iraq and Afghanistan has motivated laboratory scale experiments on biomedical effects of blast waves and studies of blast wave transmission properties of various materials in hopes of improving armor design to mitigate these injuries. This paper describes the design and performance of a table-top shock tube that is more convenient and widely accessible than traditional compression driven and blast driven shock tubes. The design is simple: it is an explosive driven shock tube employing a rifle primer that explodes when impacted by the firing pin. The firearm barrel acts as the shock tube, and the shock wave emerges from the muzzle. The small size of this shock tube can facilitate localized application of a blast wave to a subject, tissue, or material under test.

  11. A Table-top Blast Driven Shock Tube

    CERN Document Server

    Courtney, Michael; 10.1063/1.3518970

    2011-01-01

    The prevalence of blast-induced traumatic brain injury in conflicts in Iraq and Afghanistan has motivated laboratory scale experiments on biomedical effects of blast waves and studies of blast wave transmission properties of various materials in hopes of improving armor design to mitigate these injuries. This paper describes the design and performance of a table-top shock tube that is more convenient and widely accessible than traditional compression driven and blast driven shock tubes. The design is simple: it is an explosive driven shock tube employing a rifle primer which explodes when impacted by the firing pin. The firearm barrel acts as the shock tube, and the shock wave emerges from the muzzle. The small size of this shock tube can facilitate localized application of a blast wave to a subject, tissue, or material under test.

  12. Experiments in hand-operated, hypersonic shock tunnel facility

    Science.gov (United States)

    Sudhiesh Kumar, Chintoo; Reddy, K. P. J.

    2016-11-01

    Experiments were conducted using the newly developed table-top, hand-operated hypersonic shock tunnel, otherwise known as the Reddy hypersonic shock tunnel. This novel instrument uses only manual force to generate the shock wave in the shock tube, and is designed to generate a freestream flow of Mach 6.5 in the test section. The flow was characterized using stagnation point pressure measurements made using fast-acting piezoelectric transducers. Schlieren visualization was also carried out to capture the bow shock in front of a hemispherical body placed in the flow. Freestream Mach numbers estimated at various points in the test section showed that for a minimum diameter of 46 mm within the test section, the value did not vary by more than 3 % along any cross-sectional plane. The results of the experiments presented here indicate that the device may be successfully employed for basic hypersonic research activities at the university level.

  13. Storytelling and Repetitive Narratives for Design Empathy

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Judice, Andrea; Soini, Katja

    2007-01-01

    Today it is widely established in design research that empathy is an important part of creating a true understanding of user experience as a resource for design. A typical challenge is how to transmit the feeling of empathy acquired by user studies to designers who have not participated in the user...... study. In this paper, we show how we attained an empathic understanding through storytelling and aroused empathy to others using repetitive narratives in an experimental presentation bringing forth factual, reflective and experiential aspects of the user information. Taking as a starting point our...... experiences with the design project Suomenlinna Seclusive, we conclude with the potential of using narratives for invoking design empathy....

  14. Storytelling and Repetitive Narratives for Design Empathy

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Judice, Andrea; Soini, Katja

    2007-01-01

    Today it is widely established in design research that empathy is an important part of creating a true understanding of user experience as a resource for design. A typical challenge is how to transmit the feeling of empathy acquired by user studies to designers who have not participated in the user...... study. In this paper, we show how we attained an empathic understanding through storytelling and aroused empathy to others using repetitive narratives in an experimental presentation bringing forth factual, reflective and experiential aspects of the user information. Taking as a starting point our...... experiences with the design project Suomenlinna Seclusive, we conclude with the potential of using narratives for invoking design empathy....

  15. The repetitive component of the sunflower genome

    Directory of Open Access Journals (Sweden)

    T. Giordani

    2014-08-01

    Full Text Available The sunflower (Helianthus annuus and species belonging to the genus Helianthus are emerging as a model species and genus for a number of studies on genome evolution. In this review, we report on the repetitive component of the H. annuus genome at the biochemical, molecular, cytological, and genomic levels. Recent work on sunflower genome composition is described, with emphasis on different types of repeat sequences, especially LTR-retrotransposons, of which we report on isolation, characterisation, cytological localisation, transcription, dynamics of proliferation, and comparative analyses within the genus Helianthus.

  16. Thermal Shock-resistant Cement

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Pyatina, T.; Gill, S.

    2012-02-01

    We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved

  17. Shock-Induced Borehole Waves and Fracture Effects

    NARCIS (Netherlands)

    Fan, H.; Smeulders, D.M.

    2011-01-01

    We perform wave experiments using a vertical shock tube setup. Shock waves are generated by the rupture of a thin membrane. In the test section, the incident pressure waves generate borehole-guided waves along water-saturated samples. The tube is equipped with side wall gages and a mobile pressure p

  18. Kinetic theory and turbulent discontinuities. [shock tube flow

    Science.gov (United States)

    Johnson, J. A., III; I, L.; Li, Y.; Ramaian, R.; Santigo, J. P.

    1981-01-01

    Shock tube discontinuities were used to test and extend a kinetic theory of turbulence. In shock wave and contact surface fluctuations, coherent phenomena were found which provide new support for the microscopic nonempirical approach to turbulent systems, especially those with boundary layer-like instabilities.

  19. Shock-Induced Borehole Waves and Fracture Effects

    NARCIS (Netherlands)

    Fan, H.; Smeulders, D.M.

    2011-01-01

    We perform wave experiments using a vertical shock tube setup. Shock waves are generated by the rupture of a thin membrane. In the test section, the incident pressure waves generate borehole-guided waves along water-saturated samples. The tube is equipped with side wall gages and a mobile pressure p

  20. Pyruvate-Enhanced Resuscitation for Hemorrhagic Shock and Hindlimb Ischemia

    Science.gov (United States)

    2015-06-06

    Pyruvate-Enhanced Resuscitation for Hemorrhagic Shock and Hindlimb Ischemia The overall goals of this investigation were to test the ability of...Final Report: Pyruvate-Enhanced Resuscitation for Hemorrhagic Shock and Hindlimb Ischemia Report Title The overall goals of this investigation were to...during ischemia -reperfusion injury and cause cellular damage which likely contributes to myocardial contractile dysfunction. ROS oxidize and

  1. Repetition priming of words and nonwords in Alzheimer's disease and normal aging

    Science.gov (United States)

    Ober, Beth A.; Shenaut, Gregory K.

    2014-01-01

    Objective This study examines the magnitude and direction of nonword and word lexical decision repetition priming effects in Alzheimer’s disease (AD) and normal aging, focusing specifically on the negative priming effect sometimes observed with repeated nonwords. Method Probable Alzheimer's disease (AD) patients (30), elderly normal controls (34), and young normal controls (49) participated in a repetition priming experiment using low-frequency words and word-like nonwords with a letter-level orthographic orienting task at study followed by a lexical decision test phase. Results Although participants' reaction times were longer in AD compared to elderly normal, and elderly normal compared to young normal, the repetition priming effect and the degree to which the repetition priming effect was reversed for nonwords compared to words was unaffected by AD or normal aging. Conclusion AD patients, like young and elderly normal participants, are able to modify (in the case of words) and create (in the case of nonwords) long-term memory traces for lexical stimuli, based on a single orthographic processing trial. The nonword repetition results are discussed from the perspective of new vocabulary learning commencing with a provisional lexical memory trace created after orthographic encoding of a novel word-like letter string. PMID:25000325

  2. Words translated in sentence contexts produce repetition priming in visual word comprehension and spoken word production.

    Science.gov (United States)

    Francis, Wendy S; Camacho, Alejandra; Lara, Carolina

    2014-10-01

    Previous research with words read in context at encoding showed little if any long-term repetition priming. In Experiment 1, 96 Spanish-English bilinguals translated words in isolation or in sentence contexts at encoding. At test, they translated words or named pictures corresponding to words produced at encoding and control words not previously presented. Repetition priming was reliable in all conditions, but priming effects were generally smaller for contextualized than for isolated words. Repetition priming in picture naming indicated priming from production in context. A componential analysis indicated priming from comprehension in context, but only in the less fluent language. Experiment 2 was a replication of Experiment 1 with auditory presentation of the words and sentences to be translated. Repetition priming was reliable in all conditions, but priming effects were again smaller for contextualized than for isolated words. Priming in picture naming indicated priming from production in context, but the componential analysis indicated no detectable priming for auditory comprehension. The results of the two experiments taken together suggest that repetition priming reflects the long-term learning that occurs with comprehension and production exposures to words in the context of natural language.

  3. Sentence Repetition Accuracy in Adults with Developmental Language Impairment: Interactions of Participant Capacities and Sentence Structures

    Science.gov (United States)

    Poll, Gerard H.; Miller, Carol A.; van Hell, Janet G.

    2016-01-01

    Purpose: We asked whether sentence repetition accuracy could be explained by interactions of participant processing limitations with the structures of the sentences. We also tested a prediction of the procedural deficit hypothesis (Ullman & Pierpont, 2005) that adjuncts are more difficult than arguments for individuals with developmental…

  4. Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with Motor Learning by Observing

    Science.gov (United States)

    Brown, Liana E.; Wilson, Elizabeth T.; Gribble, Paul L.

    2009-01-01

    Neural representations of novel motor skills can be acquired through visual observation. We used repetitive transcranial magnetic stimulation (rTMS) to test the idea that this "motor learning by observing" is based on engagement of neural processes for learning in the primary motor cortex (M1). Human subjects who observed another person learning…

  5. Tibialis anterior stretch reflex in early stance is suppressed by repetitive transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Zuur, Abraham T; Christensen, Mark Schram; Sinkjær, Thomas

    2009-01-01

    Abstract A rapid plantar flexion perturbation in the early stance phase of walking elicits a large stretch reflex in tibialis anterior (TA). In this study we use repetitive Transcranial Magnetic Stimulation (rTMS) to test if this response is mediated through a transcortical pathway. TA stretch...

  6. Excessive Response-Repetition Costs under Task Switching: How Response Inhibition Amplifies Response Conflict

    Science.gov (United States)

    Grzyb, Kai Robin; Hubner, Ronald

    2013-01-01

    The size of response-repetition (RR) costs, which are usually observed on task-switch trials, strongly varies between conditions with univalent and bivalent stimuli. To test whether top-down or bottom-up processes can account for this effect, we assessed in Experiment 1 baselines for univalent and bivalent stimulus conditions (i.e., for stimuli…

  7. Complexity and Shock Wave Geometries

    CERN Document Server

    Stanford, Douglas

    2014-01-01

    In this paper we refine a conjecture relating the time-dependent size of an Einstein-Rosen bridge to the computational complexity of the of the dual quantum state. Our refinement states that the complexity is proportional to the spatial volume of the ERB. More precisely, up to an ambiguous numerical coefficient, we propose that the complexity is the regularized volume of the largest codimension one surface crossing the bridge, divided by $G_N l_{AdS}$. We test this conjecture against a wide variety of spherically symmetric shock wave geometries in different dimensions. We find detailed agreement.

  8. Observations and simulations of specularly reflected He++ at Earth's quasiperpendicular bow shock

    Science.gov (United States)

    Broll, J. M.; Fuselier, S. A.; Trattner, K. J.; Anderson, B. J.; Burch, J. L.; Giles, B. L.

    2016-12-01

    Specular reflection of protons at Earth's quasiperpendicular bow shock is an important process for supercritical shock dissipation. Previous studies have found evidence of He++ specular reflection from reduced particle distributions downstream from the shock, but confirmation of the process for heavier ions in the shock foot was not possible due to time resolution constraints. We present He++ distributions, observed by MMS in a quasiperpendicular bow shock crossing, that are consistent with specularly reflected He++. We also investigate the He++ dynamics with test-particle simulations in a simulated shock based on this crossing and we conduct wave analysis to determine what processes lead to separate gyrotropization timescales for the transmitted and reflected populations.

  9. Basis Function Repetitive And Feedback Control With Application To A Particle Accelerator

    CERN Document Server

    Akogyeram, R A

    2002-01-01

    The thesis addresses three problem areas within repetitive control. Firstly, it addresses issues concerning the ability of repetitive control and feedback control systems to eliminate periodic disturbances occurring above the Nyquist frequency of the hardware. Methods are developed for decomposing and unfolding notch filter or comb filter feedback control so that disturbances above Nyquist frequency can be canceled. Phenomena affecting final error levels are discussed, including error in unfolding, coarseness of zero-order hold cancellation, and waterbed effects in the feedback control system frequency response for different sample rates. Secondly, matched basis function repetitive control laws are developed for batch mode and real time implementation to converge to zero tracking error in the presence of periodic disturbances. For both control methods, conditions are given that guarantee asymptotic and monotonic convergence. Stability tests are formulated to examine stability when the period of a disturbance ...

  10. Investigating the work-family conflict and health link: Repetitive thought as a mechanism.

    Science.gov (United States)

    Davis, Kelly D; Gere, Judith; Sliwinski, Martin J

    2016-10-06

    Research is needed to investigate mechanisms linking work-family conflict to poor health in working adults. We took a novel approach to build on extant studies by testing a potential mechanism in these associations - repetitive thought. Data came from a sample of 203 partnered working adults. There were significant direct effects of work-family conflict with lower life satisfaction, positive affect, and perceived health as well as greater fatigue. As for total effects, work-family conflict was significantly associated with all health outcomes - life satisfaction, positive affect, negative affect, fatigue, perceived health, and chronic health conditions - in the expected directions through repetitive thought. This study provides support that repetitive thought is one potential mechanism of how work-family conflict can take a toll on psychological and physical health. Findings are discussed in relation to improving workplace policies to improve the health of working adults managing work-family conflict.

  11. A vacuum-sealed, gigawatt-class, repetitively pulsed high-power microwave source

    Science.gov (United States)

    Xun, Tao; Fan, Yu-wei; Yang, Han-wu; Zhang, Zi-cheng; Chen, Dong-qun; Zhang, Jian-de

    2017-06-01

    A compact L-band sealed-tube magnetically insulated transmission line oscillator (MILO) has been developed that does not require bulky external vacuum pump for repetitive operations. This device with a ceramic insulated vacuum interface, a carbon fiber array cathode, and non-evaporable getters has a base vacuum pressure in the low 10-6 Pa range. A dynamic 3-D Monte-Carlo model for the molecular flow movement and collision was setup for the MILO chamber. The pulse desorption, gas evolution, and pressure distribution were exactly simulated. In the 5 Hz repetition rate experiments, using a 600 kV diode voltage and 48 kA beam current, the average radiated microwave power for 25 shots is about 3.4 GW in 45 ns pulse duration. The maximum equilibrium pressure is below 4.0 × 10-2 Pa, and no pulse shortening limitations are observed during the repetitive test in the sealed-tube condition.

  12. The accumulation of brain injury leads to severe neuropathological and neurobehavioral changes after repetitive mild traumatic brain injury.

    Science.gov (United States)

    Gao, Huabin; Han, Zhaoli; Bai, Ruojing; Huang, Shan; Ge, Xintong; Chen, Fanglian; Lei, Ping

    2017-02-15

    Traumatic brain injury (TBI) is a major public health problem with long-term neurobehavioral sequela. The evidences have revealed that TBI is a risk factor for later development of neurodegenerative disease and both the single and repetitive brain injury can lead to the neurodegeneration. But whether the effects of accumulation play an important role in the neurodegenerative disease is still unknown. We utilized the Sprague Dawley (SD) rats to develop the animal models of repetitive mild TBI and single mild TBI in order to detect the neurobehavioral changes. The results of neurobehavioral test revealed that the repetitive mild TBI led to more severe behavioral injuries than the single TBI. There were more activated microglia cells and astrocytes in the repetitive mild TBI group than the single TBI group. In consistent with this, the levels of TNF-α and IL-6 were higher and the expression of IL-10 was lower in the repetitive mild TBI group compared with the single TBI group. The expression of amyloid precursor protein (APP) increased in the repetitive TBI group detected by ELISA and western blot. But the levels of total tau (Tau-5) and P-tau (ser202) seem no different between the two groups in most time point. In conclusion, repetitive mild TBI could lead to more severe neurobehavioral impairments and the effects of accumulation may be associated with the increased inflammation in the brain. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Are shocks to commodity prices persistent?

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Paresh Kumar; Liu, Ruipeng [School of Accounting, Economics and Finance, Deakin University (Australia)

    2011-01-15

    This paper considers the issue of whether shocks to ten commodity prices (gold, silver, platinum, copper, aluminum, iron ore, lead, nickel, tin, and zinc) are persistent or transitory. We use two recently developed unit root tests, namely the Narayan and Popp (NP) test and the Liu and Narayan (LN) test. Both tests allow for two structural breaks in the data series. Using the NP test, we are able to reject the unit root null for iron ore and tin. Using the GARCH-based unit root test of LN, we are able to reject the unit root null for five commodity prices (iron ore, nickel, zinc, lead, and tin). Our findings, thus, suggest that only shocks to gold, silver, platinum, aluminum, and copper are persistent. (author)

  14. Trade-offs between predator avoidance and electric shock avoidance in hermit crabs demonstrate a non-reflexive response to noxious stimuli consistent with prediction of pain.

    Science.gov (United States)

    Magee, Barry; Elwood, Robert W

    2016-09-01

    Arthropods have long been thought to respond to noxious stimuli by reflex reaction. One way of testing if this is true is to provide the animal with a way to avoid the stimulus but to vary the potential cost of avoidance. If avoidance varies with potential cost then a decision making process is evident and the behaviour is not a mere reflex. Here we examine the responses of hermit crabs to electric shock within their shell when also exposed to predator or non-predator odours or to no odour. The electric shocks start with low voltage but increase in voltage with each repetition to determine how odour affects the voltage at which the shell is abandoned. There was no treatment effect on the voltage at which hermit crabs left their shells, however, those exposed to predator odours were less likely to evacuate their shells compared with no odour or low concentrations of non-predator odour. However, highly concentrated non-predator also inhibited evacuation. The data show that these crabs trade-off avoidance of electric shock with predator avoidance. They are thus not responding purely by reflex and the data are thus consistent with predictions of pain but do not prove pain.

  15. Oxotremorine treatment reduces repetitive behaviors in BTBR T+ tf/J mice

    Directory of Open Access Journals (Sweden)

    Dionisio A. Amodeo

    2014-08-01

    Full Text Available Repetitive behaviors with restricted interests is one of the core criteria for the diagnosis of autism spectrum disorder (ASD. Current pharmacotherapies that target the dopaminergic or serotonergic systems have limited effectiveness in treating repetitive behaviors. Previous research has demonstrated that administration of muscarinic cholinergic receptor (mAChR antagonists can exacerbate motor stereotypies while mAChR agonists reduce stereotypies. The present study determined whether the mAChR agonist, oxotremorine affected repetitive behaviors in the BTBR T+ tf/J (BTBR mouse model of autism. To test the effects of oxotremorine on repetitive behaviors, marble burying and grooming behavior were measured in BTBR mice and compared to that in C57BL/6J (B6 mice. The effects of oxotremorine on locomotor activity was also measured. Thirty minutes before each test, mice received an intraperitoneal injection of saline, 0.001 mg or 0.01 mg of oxotremorine methiodide. Saline- treated BTBR mice exhibited increased marble burying and self-grooming behavior compared to that of saline-treated B6 mice. Oxotremorine significantly reduced marble burying and self-grooming behavior in BTBR mice, but had no significant effect in B6 mice. In addition, oxotremorine did not affect locomotor activity in BTBR mice, but significantly reduced locomotor activity in B6 mice at the 0.01 mg dose. These findings demonstrate that activation of mAChRs reduces repetitive behavior in the BTBR mouse and suggest that treatment with a mAChR agonist may be effective in reducing repetitive behaviors in ASD.

  16. Is There a Need for Repetition of Skin Test in Childhood Allergic Diseases? Repetition of Skin Test and Allergic Diseases

    Directory of Open Access Journals (Sweden)

    Mahmut Dogru

    2014-01-01

    Conclusions: It is found that there was an alteration of sensitization in 4/10 children at the end of the average 4-year period. The presence of family atopy, the presence of allergic rhinitis and serum total IgE elevation were risk factors for the development of new sensitization. On the other hand sensitization to multiple allergens was risk factors for the loss of sensitization.

  17. Gram-positive toxic shock syndromes.

    Science.gov (United States)

    Lappin, Emma; Ferguson, Andrew J

    2009-05-01

    Toxic shock syndrome (TSS) is an acute, multi-system, toxin-mediated illness, often resulting in multi-organ failure. It represents the most fulminant expression of a spectrum of diseases caused by toxin-producing strains of Staphylococcus aureus and Streptococcus pyogenes (group A streptococcus). The importance of Gram-positive organisms as pathogens is increasing, and TSS is likely to be underdiagnosed in patients with staphylococcal or group A streptococcal infection who present with shock. TSS results from the ability of bacterial toxins to act as superantigens, stimulating immune-cell expansion and rampant cytokine expression in a manner that bypasses normal MHC-restricted antigen processing. A repetitive cycle of cell stimulation and cytokine release results in a cytokine avalanche that causes tissue damage, disseminated intravascular coagulation, and organ dysfunction. Specific therapy focuses on early identification of the illness, source control, and administration on antimicrobial agents including drugs capable of suppressing toxin production (eg, clindamycin, linezolid). Intravenous immunoglobulin has the potential to neutralise superantigen and to mitigate subsequent tissue damage.

  18. Measurement of impulse peak insertion loss from two acoustic test fixtures and four hearing protector conditions with an acoustic shock tube

    OpenAIRE

    Murphy, William J.; Cameron J Fackler; Berger, Elliott H.; Peter B Shaw; Mike Stergar

    2015-01-01

    Impulse peak insertion loss (IPIL) was studied with two acoustic test fixtures and four hearing protector conditions at the E-A-RCAL Laboratory. IPIL is the difference between the maximum estimated pressure for the open-ear condition and the maximum pressure measured when a hearing protector is placed on an acoustic test fixture (ATF). Two models of an ATF manufactured by the French-German Research Institute of Saint-Louis (ISL) were evaluated with high-level acoustic impulses created by an a...

  19. No discrimination shock avoidance with sequential presentation of stimuli but shore crabs still reduce shock exposure.

    Science.gov (United States)

    Magee, Barry; Elwood, Robert W

    2016-07-15

    Insights into the potential for pain may be obtained from examination of behavioural responses to noxious stimuli. In particular, prolonged responses coupled with long-term motivational change and avoidance learning cannot be explained by nociceptive reflex but are consistent with the idea of pain. Here, we placed shore crabs alternately in two halves of a test area divided by an opaque partition. Each area had a dark shelter and in one repeated small electric shocks were delivered in an experimental but not in a control group. Crabs showed no specific avoidance of the shock shelter either during these trials or in a subsequent test in which both were offered simultaneously; however they often emerged from the shock shelter during a trial and thus avoided further shock. More crabs emerged in later trials and took less time to emerge than in early trials. Thus, despite the lack of discrimination learning between the two shelters they used other tactics to markedly reduce the amount of shock received. We note that a previous experiment using simultaneous presentation of two shelters demonstrated rapid discrimination and avoidance learning but the paradigm of sequential presentation appears to prevent this. Nevertheless, the data show clearly that the shock is aversive and tactics, other than discrimination learning, are used to avoid it. Thus, the behaviour is only partially consistent with the idea of pain.

  20. Relativistic Radiation Mediated Shocks

    CERN Document Server

    Budnik, Ran; Sagiv, Amir; Waxman, Eli

    2010-01-01

    The structure of relativistic radiation mediated shocks (RRMS) propagating into a cold electron-proton plasma is calculated and analyzed. A qualitative discussion of the physics of relativistic and non relativistic shocks, including order of magnitude estimates for the relevant temperature and length scales, is presented. Detailed numerical solutions are derived for shock Lorentz factors $\\Gamma_u$ in the range $6\\le\\Gamma_u\\le30$, using a novel iteration technique solving the hydrodynamics and radiation transport equations (the protons, electrons and positrons are argued to be coupled by collective plasma processes and are treated as a fluid). The shock transition (deceleration) region, where the Lorentz factor $ \\Gamma $ drops from $ \\Gamma_u $ to $ \\sim 1 $, is characterized by high plasma temperatures $ T\\sim \\Gamma m_ec^2 $ and highly anisotropic radiation, with characteristic shock-frame energy of upstream and downstream going photons of a few~$\\times\\, m_ec^2$ and $\\sim \\Gamma^2 m_ec^2$, respectively.P...

  1. Repetitive Bunches from RF-Photo Gun Radiate Coherently

    CERN Document Server

    Van der Geer, C A J; Van der Geer, S B

    2004-01-01

    We consider to feed the laser wake field accelerator of the alpha-X project by a train of low charge pancake electron bunches to reduce undesired expansion due to space-charge forces. To this purpose the photo excitation laser of the rf-injector is split into a train of sub-pulses, such that each of the produced electron bunches falls into a successive ponderomotive well of the plasma accelerator. This way the total accelerated charge is not reduced. The repetitive photo gun can be tested, at low energy, by connecting it directly to the undulator and monitoring the radiation. The assertions are based on the results of new GPT simulations.

  2. Therapeutic benefit of repetitive transcranial magnetic stimulation for severe mirror movements A case report

    Institute of Scientific and Technical Information of China (English)

    Han Sun Kim; Sung Ho Jang; Zee-Ihn Lee; Mi Young Lee; Yun Woo Cho; Migyoung Kweon; Su Min Son

    2013-01-01

    Congenital mirror movements retard typical hand functions, but no definite therapeutic modality is available to treat such movements. We report an 8-year-old boy with severe mirror movements of both hands. His mirror movements were assessed using the Woods and Teuber grading scale and his fine motor skills were also evaluated by the Purdue Pegboard Test. A 2-week regimen of repetitive transcranial magnetic stimulation produced markedly diminished mirror movement symptoms and increased the fine motor skills of both hands. Two weeks after the completion of the regimen, mirror movement grades had improved from grade 4 to 1 in both hands and the Purdue Pegboard Test results of the right and left hands also improved from 12 to 14 or 13. These improvements were maintained for 1 month after the 2-week repetitive transcranial magnetic stimulation regimen. After 18 months, the mirror movement grade was maintained and the Purdue Pegboard test score had improved to 15 for the right hand while the left hand score was maintained at 13. This occurred without any additional repetitive transcranial magnetic stimulation or other treatment. These findings suggest that repetitive transcranial magnetic stimulation for this patient had a therapeutic and long-term effect on mirror movements.

  3. Sensory dysfunction associated with repetitive strain injuries of tendinitis and focal hand dystonia: a comparative study.

    Science.gov (United States)

    Byl, N; Wilson, F; Merzenich, M; Melnick, M; Scott, P; Oakes, A; McKenzie, A

    1996-04-01

    Repetitive strain injuries are reaching epidemic levels among workers who perform heavy schedules of rapid alternating movements (eg., computer programmers, data entry workers) or repetitive, sustained, coordinated movements (eg., editors, writers, salespeople). The purpose of this study was to determine if patients with repetitive strain injury demonstrated degraded sensory motor performance with their hands. Sixty age-matched adults were recruited, with 15 each assigned to a healthy adult control group, a healthy musician control group, a tendinitis group, or a focal dystonia group. Four sensory motor subtests from the Sensory Integration and Praxis Test were given to the subjects according to a standardized protocol. Using multiple one-factor analyses of variance in the parametric or nonparametric mode followed by post hoc pairwise testing, no significant differences were found between the healthy controls and the musician controls. On the test of kinesthesia, using the left hand, subjects with tendinitis performed significantly worse than controls and subjects with focal dystonia. Compared with controls, subjects with focal dystonia did significantly worse on graphesthesia and manual form perception (part 1 and part 2). Subjects with focal dystonia also did significantly worse than subjects with tendinitis when using the left hand on graphesthesia and manual form perception (part 2). When treating patients with repetitive strain injury, discriminative sensory motor skills must be carefully assessed and may need to be addressed as part of an effective treatment program.

  4. Shock Detector for SURF model

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-11

    SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

  5. Shock Detector for SURF model

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-11

    SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

  6. A phonetic approach to consonant repetition in early words.

    Science.gov (United States)

    Kim, Namhee; Davis, Barbara L

    2015-08-01

    The goal of this study was to evaluate movement-based principles for understanding early speech output patterns. Consonant repetition patterns within children's actual productions of word forms were analyzed using spontaneous speech data from 10 typically developing American-English learning children between 12 and 36 months of age. Place of articulation, word level patterns, and developmental trends in CVC and CVCV repeated word forms were evaluated. Labial and coronal place repetitions dominated. Regressive repetition (e.g., [gag] for "dog") occurred frequently in CVC but not in CVCV word forms. Consonant repetition decreased over time. However, the children produced sound types available reported as being within young children's production system capabilities in consonant repetitions in all time periods. Findings suggest that a movement-based approach can provide a framework for comprehensively characterizing consonant place repetition patterns in early speech development.

  7. Repetition and Reactance in Graham’s "Underneath" Poems

    Directory of Open Access Journals (Sweden)

    Roghayeh Farsi

    2017-09-01

    Full Text Available The present paper gives a detailed analysis and interpretation of 16 poems in Jorie Graham's collection, Swarm (2000, which bear "UNDERNEATH" as their main titles. The poems are marked with different types of repetition such as graphological repetition, word, phrase, and sentential repetition, semantic repetition, and syntactic repetition. The study draws on Lakoff and Johnson's theories on metaphor and Brehm and Brehm’s reactance theory. It is argued "underneath" is a conceptual (orientational metaphor which signifies a state of being limited, lack of control and freedom, and loss of power. The paper investigates the speaker's reactant behavior in "Underneath" poems, seeking a way to restore her lost freedom. Reactance behaviors can be skepticism, inertia, aggression, and resistance. It is concluded despite her thematic inertia, representing her submission to the oppressed state, her stylistic reactance reflected in repetitions, innovations, and disruptive diction stands for her attempts to regain her lost control.

  8. Shock wave fabricated ceramic-metal nozzles

    NARCIS (Netherlands)

    Carton, E.P.; Stuivinga, M.E.C.; Keizers, H.L.J.; Verbeek, H.J.; Put, P.J. van der

    1999-01-01

    Shock compaction was used in the fabrication of high temperature ceramic-based materials. The materials' development was geared towards the fabrication of nozzles for rocket engines using solid propellants, for which the following metal-ceramic (cermet) materials were fabricated and tested: B4C-Ti (

  9. Shock wave fabricated ceramic-metal nozzles

    NARCIS (Netherlands)

    Carton, E.P.; Stuivinga, M.E.C.; Keizers, H.L.J.; Verbeek, H.J.; Put, P.J. van der

    1999-01-01

    Shock compaction was used in the fabrication of high temperature ceramic-based materials. The materials' development was geared towards the fabrication of nozzles for rocket engines using solid propellants, for which the following metal-ceramic (cermet) materials were fabricated and tested: B4C-Ti

  10. [Anaphylactic shock caused by fibrin glue].

    Science.gov (United States)

    Orsel, I; Guillaume, A; Feiss, P

    1997-01-01

    We observed a case of anaphylactic shock in a 68-year-old woman after a nasal intramucosal injection of fibrin glue for telangiectasies therapy. The tests showed an allergy to aprotinin contained in the glue. In the previous years, glue and aprotinin had been administered to the patient several times for nasal bleeding.

  11. Physics of Collisionless Shocks Space Plasma Shock Waves

    CERN Document Server

    Balogh, André

    2013-01-01

    The present book provides a contemporary systematic treatment of shock waves in high-temperature collisionless plasmas as are encountered in near Earth space and in Astrophysics. It consists of two parts. Part I develops the complete theory of shocks in dilute hot plasmas under the assumption of absence of collisions among the charged particles when the interaction is mediated solely by the self-consistent electromagnetic fields. Such shocks are naturally magnetised implying that the magnetic field plays an important role in their evolution and dynamics. This part treats both subcritical shocks, which dissipate flow energy by generating anomalous resistance or viscosity, and supercritical shocks. The main emphasis is, however, on super-critical shocks where the anomalous dissipation is insufficient to retard the upstream flow. These shocks, depending on the direction of the upstream magnetic field, are distinguished as quasi-perpendicular and quasi-parallel shocks which exhibit different behaviours, reflecti...

  12. Shock wave reflection phenomena

    CERN Document Server

    Ben-dor, Gabi

    2007-01-01

    This book provides a comprehensive state-of-the-knowledge description of the shock wave reflection phenomena from a phenomenological point of view. The first part is a thorough introduction to oblique shock wave reflections, presenting the two major well-known reflection wave configurations, namely, regular (RR) and Mach (MR) reflections, the corresponding two- and three-shock theories, their analytical and graphical solution and the proposed transition boundaries between these two reflection-wave configurations. The second, third and fourth parts describe the reflection phenomena in steady, pseudo-steady and unsteady flows, respectively. Here, the possible specific types of reflection wave configurations are described, criteria for their formation and termination are presented and their governing equations are solved analytically and graphically and compared with experimental results. The resolution of the well-known von Neumann paradox and a detailed description of two new reflection-wave configurations - t...

  13. FEMA Hazard Mitigation Assistance Repetitive Flood Claims (RFC) Data

    Data.gov (United States)

    Department of Homeland Security — This dataset contains closed and obligated projects funded under the following Hazard Mitigation Assistance (HMA) grant programs: Repetitive Flood Claims (RFC). The...

  14. A review of neuroimaging findings in repetitive brain trauma.

    Science.gov (United States)

    Koerte, Inga K; Lin, Alexander P; Willems, Anna; Muehlmann, Marc; Hufschmidt, Jakob; Coleman, Michael J; Green, Isobel; Liao, Huijun; Tate, David F; Wilde, Elisabeth A; Pasternak, Ofer; Bouix, Sylvain; Rathi, Yogesh; Bigler, Erin D; Stern, Robert A; Shenton, Martha E

    2015-05-01

    Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease confirmed at postmortem. Those at highest risk are professional athletes who participate in contact sports and military personnel who are exposed to repetitive blast events. All neuropathologically confirmed CTE cases, to date, have had a history of repetitive head impacts. This suggests that repetitive head impacts may be necessary for the initiation of the pathogenetic cascade that, in some cases, leads to CTE. Importantly, while all CTE appears to result from repetitive brain trauma, not all repetitive brain trauma results in CTE. Magnetic resonance imaging has great potential for understanding better the underlying mechanisms of repetitive brain trauma. In this review, we provide an overview of advanced imaging techniques currently used to investigate brain anomalies. We also provide an overview of neuroimaging findings in those exposed to repetitive head impacts in the acute/subacute and chronic phase of injury and in more neurodegenerative phases of injury, as well as in military personnel exposed to repetitive head impacts. Finally, we discuss future directions for research that will likely lead to a better understanding of the underlying mechanisms separating those who recover from repetitive brain trauma vs. those who go on to develop CTE.

  15. FEMA Hazard Mitigation Assistance Severe Repetitive Loss (SRL) Data

    Data.gov (United States)

    Department of Homeland Security — This dataset contains closed and obligated projects funded under the following Hazard Mitigation Assistance (HMA) grant programs: Severe Repetitive Loss (SRL). The...

  16. [Traumatic neurogenic shock].

    Science.gov (United States)

    Maurin, O; de Régloix, S; Caballé, D; Arvis, A-M; Perrochon, J-C; Tourtier, J-P

    2013-05-01

    Traumatic neurogenic shock is a rare but serious complication of spinal cord injury. It associates bradycardia and hypotension caused by a medullary trauma. It is life-threatening for the patient and it aggravates the neurological deficit. Strict immobilization and a quick assessment of the gravity of cord injury are necessary as soon as prehospital care has begun. Initial treatment requires vasopressors associated with fluid resuscitation. Steroids are not recommended. Early decompression is recommended for incomplete deficit seen in the first 6 hours. We relate the case of secondary spinal shock to a luxation C6/C7 treated in prehospital care.

  17. [Corticosteroids and septic shock].

    Science.gov (United States)

    Bouletreau, P; Petit, P; Latarjet, J

    1976-01-01

    According to the data in the literature, the authors attempted to sum-up present attitudes on the value of corticoids in the treatment of septic shock. If their cardiovascular effects after a period of enthusiasm, are presently rather controversial, their cellular and sub-cellular actions, on the lysosomal membranes, capillary permeability and perhaps the intimate mechanisms of cellular oxygenation seem to be more real. However, the contra-indications which persist in the results of clinical works have resulted in the fact that the exact place of cortico-steroids in the therapeutic arsenal of septic shock still remains to be specified.

  18. Culture shock and travelers.

    Science.gov (United States)

    Stewart, L; Leggat, P A

    1998-06-01

    As travel has become easier and more affordable, the number of people traveling has risen sharply. People travel for many and varied reasons, from the business person on an overseas assignment to backpackers seeking new and exotic destinations. Others may take up residence in different regions, states or countries for family, business or political reasons. Other people are fleeing religious or political persecution. Wherever they go and for whatever reason they go, people take their culture with them. Culture, like language, is acquired innately in early childhood and is then reinforced through formal and complex informal social education into adulthood. Culture provides a framework for interpersonal and social interactions. Therefore, the contact with a new culture is often not the exciting or pleasurable experience anticipated. When immersed in a different culture, people no longer know how to act when faced with disparate value systems. Contact with the unfamiliar culture can lead to anxiety, stress, mental illness and, in extreme cases, physical illness and suicide. "Culture shock" is a term coined by the anthropologist Oberg. It is the shock of the new. It implies that the experience of the new culture is an unpleasant surprise or shock, partly because it is unexpected and partly because it can lead to a negative evaluation of one's own culture. It is also known as cross-cultural adjustment, being that period of anxiety and confusion experienced when entering a new culture. It affects people intellectually, emotionally, behaviorally and physically and is characterized by symptoms of psychological distress. Culture shock affects both adults and children. In travelers or workers who have prolonged sojourns in foreign countries, culture shock may occur not only as they enter the new culture, but also may occur on their return to their original culture. Children may also experience readjustment problems after returning from leading sheltered lives in expatriate

  19. Characteristics of Weak Interplanetary Shocks and Shock-like Events

    Science.gov (United States)

    Balogh, A.; Gloag, J. M.

    The variation of magnetic and plasma parameters across the discontinuity of a colli- sionless shock wave are clearly understood and presented in MHD theory. The anal- ysis of 116 shock waves appearing on the Ulysses shock list in the period mid 1996 to the end of 1999 show that in the cases of the stronger shock waves, measured by the ratio of downstream to upstream magnetic field magnitudes, this MHD descrip- tion is adequate. However in the case of many of the weaker shocks there are events which are not clearly characterised in MHD terms and in these cases plasma param- eters are particularly difficult to interpret. To explore the issues associated with these very weak shocks further, a set of shock-like events is considered which have shock characteristics in the high frequency wave data measured by the plasma wave inves- tigation(URAP) but are not considered to be clearly shock waves purely considering magnetic and plasma data. These shock-like events are thought to extend the spectrum of interplanetary shocks at the very weakest end and possibly beyond what should be considered a collisionless shock wave.

  20. Repetitive control of electrically driven robot manipulators

    Science.gov (United States)

    Fateh, Mohammad Mehdi; Ahsani Tehrani, Hojjat; Karbassi, Seyed Mehdi

    2013-04-01

    This article presents a novel robust discrete repetitive control of electrically driven robot manipulators for tracking of a periodic trajectory. We propose a novel model, which presents the highly non-linear dynamics of robot manipulator in the form of linear discrete-time time-varying system. Based on the proposed model, we develop a two-term control law. The first term is an ordinary time-optimal and minimum-norm (TOMN) control by employing parametric controllers to guarantee stability. The second term is a novel robust control to improve the control performance in the face of uncertainties. The robust control estimates and compensates uncertainties including the parametric uncertainty, unmodelled dynamics and external disturbances. Performance of the proposed method is compared with two discrete methods, namely the TOMN control and an adaptive iterative learning (AIL) control. Simulation results confirm superiority of the proposed method in terms of the convergence speed and precision.

  1. Results from Recent NIF Shock Timing Experiments

    Science.gov (United States)

    Robey, H. F.; Celliers, P. M.; Boehly, T. R.; Kline, J. L.; Bowers, M. W.; Le Pape, S.; Farley, D. R.; MacKinnon, A. J.; Moody, J. D.; Eggert, J. H.; Munro, D. H.; Jones, O. S.; Milovich, J. L.; Clark, D.; Nikroo, A.; Moreno, K. A.; Kroll, J. J.; Hamza, A. V.; Barker, D. A.; Landen, O. L.; Edwards, M. J.; Meyerhofer, D. D.

    2011-10-01

    Experiments are underway to tune the shock timing of capsule implosions on the National Ignition Facility (NIF). These experiments use a modified cryogenic hohlraum geometry designed to precisely match the performance of ignition hohlraums. The targets employ a re-entrant Au cone to provide optical access to multiple shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of all four shocks is diagnosed with VISAR (Velocity Interferometer System for Any Reflector). The tuned pulse shape resulting from these experiments has been tested in ignition capsule implosions and demonstrates a considerable improvement in fuel adiabat. Experimental results and comparisons with numerical simulation are presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

  2. Flow behind concave shock waves

    Science.gov (United States)

    Mölder, S.

    2017-03-01

    Curved shock theory is introduced and applied to calculate the flow behind concave shock waves. For sonic conditions, three characterizing types of flow are identified, based on the orientation of the sonic line, and it is shown that, depending on the ratio of shock curvatures, a continuously curving shock can exist with Type III flow, where the sonic line intercepts the reflected characteristics from the shock, thus preventing the formation of a reflected shock. The necessary shock curvature ratio for a Type III sonic point does not exist for a hyperbolic shock so that it will revert to Mach reflection for all Mach numbers. A demonstration is provided, by CFD calculations, at Mach 1.2 and 3.

  3. Flow behind concave shock waves

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Curved shock theory is introduced and applied to calculate the flow behind concave shock waves. For sonic conditions, three characterizing types of flow are identified, based on the orientation of the sonic line, and it is shown that, depending on the ratio of shock curvatures, a continuously curving shock can exist with Type III flow, where the sonic line intercepts the reflected characteristics from the shock, thus preventing the formation of a reflected shock. The necessary shock curvature ratio for a Type III sonic point does not exist for a hyperbolic shock so that it will revert to Mach reflection for all Mach numbers. A demonstration is provided, by CFD calculations, at Mach 1.2 and 3.

  4. Sands subjected to repetitive vertical loading under zero lateral strain: accumulation models, terminal densities, and settlement

    KAUST Repository

    Chong, Song Hun

    2016-08-09

    Geosystems often experience numerous loading cycles. Plastic strain accumulation during repetitive mechanical loads can lead to shear shakedown or continued shear ratcheting; in all cases, volumetric strains diminish as the specimen evolves towards terminal density. Previously suggested models and new functions are identified to fit plastic strain accumulation data. All accumulation models are formulated to capture terminal density (volumetric strain) and either shakedown or ratcheting (shear strain). Repetitive vertical loading tests under zero lateral strain conditions are conducted using three different sands packed at initially low and high densities. Test results show that plastic strain accumulation for all sands and density conditions can be captured in the same dimensionless plot defined in terms of the initial relative density, terminal density, and ratio between the amplitude of the repetitive load and the initial static load. This observation allows us to advance a simple but robust procedure to estimate the maximum one-dimensional settlement that a foundation could experience if subjected to repetitive loads. © 2016, Canadian Science Publishing. All rights reserved.

  5. Shock compression of polyvinyl chloride

    Science.gov (United States)

    Neogi, Anupam; Mitra, Nilanjan

    2016-04-01

    This study presents shock compression simulation of atactic polyvinyl chloride (PVC) using ab-initio and classical molecular dynamics. The manuscript also identifies the limits of applicability of classical molecular dynamics based shock compression simulation for PVC. The mechanism of bond dissociation under shock loading and its progression is demonstrated in this manuscript using the density functional theory based molecular dynamics simulations. The rate of dissociation of different bonds at different shock velocities is also presented in this manuscript.

  6. Shock conditions for hypoelastic materials

    Science.gov (United States)

    Renardy, Michael; Rogers, Robert C.

    1993-10-01

    The equations governing the motion of hypoelastic materials (and related models of non-Newtonian fluids) are not in conservation form. Hence there is no obvious formulation of Rankine-Hugoniot jump conditions across a shock. In this paper we demonstrate that a viscosity criterion can be used to obtain meaningful shock conditions. In particular, we discuss shocks of small amplitude. The shock conditions obtained will in general depend on the form of the viscosity term.

  7. Heat shock and heat shock protein 70i enhance the oncolytic effect of replicative adenovirus.

    Science.gov (United States)

    Haviv, Y S; Blackwell, J L; Li, H; Wang, M; Lei, X; Curiel, D T

    2001-12-01

    Replication-competent viruses are currently being evaluated for their cancer cell-killing properties. These vectors are designed to induce tumor regression after selective viral propagation within the tumor. However, replication-competent viruses have not resulted heretofore in complete tumor eradication in the clinical setting. Recently, heat shock has been reported to partially alleviate replication restriction on an avian adenovirus (Ad) in a human lung cancer cell line. Therefore, we hypothesized that heat shock and overexpression of heat shock protein (hsp) would support the oncolytic effect of a replication-competent human Ad. To this end, we tested the oncolytic and burst kinetics of a replication-competent Ad after exposure to heat shock or to inducible hsp 70 overexpression by a replication-deficient Ad (Adhsp 70i). Heat-shock resulted in augmentation of Ad burst and oncolysis while decreasing total intracellular Ad DNA. Overexpression of hsp 70i also enhanced Ad-mediated oncolysis but did not decrease intracellular Ad DNA levels. We conclude that heat shock and Adhsp 70i enhance the Ad cell-killing potential via distinct mechanisms. A potential therapeutic implication would be the use of local hyperthermia to augment oncolysis by increasing the burst of replication-competent Ad. The role of hsp in Ad-mediated oncolysis should be additionally explored.

  8. STEREO interplanetary shocks and foreshocks

    Energy Technology Data Exchange (ETDEWEB)

    Blanco-Cano, X. [Instituto de Geofisica, UNAM, CU, Coyoacan 04510 DF (Mexico); Kajdic, P. [IRAP-University of Toulouse, CNRS, Toulouse (France); Aguilar-Rodriguez, E. [Instituto de Geofisica, UNAM, Morelia (Mexico); Russell, C. T. [ESS and IGPP, University of California, Los Angeles, 603 Charles Young Drive, Los Angeles, CA 90095 (United States); Jian, L. K. [NASA Goddard Space Flight Center, Greenbelt, MD and University of Maryland, College Park, MD (United States); Luhmann, J. G. [SSL, University of California Berkeley (United States)

    2013-06-13

    We use STEREO data to study shocks driven by stream interactions and the waves associated with them. During the years of the extended solar minimum 2007-2010, stream interaction shocks have Mach numbers between 1.1-3.8 and {theta}{sub Bn}{approx}20-86 Degree-Sign . We find a variety of waves, including whistlers and low frequency fluctuations. Upstream whistler waves may be generated at the shock and upstream ultra low frequency (ULF) waves can be driven locally by ion instabilities. The downstream wave spectra can be formed by both, locally generated perturbations, and shock transmitted waves. We find that many quasiperpendicular shocks can be accompanied by ULF wave and ion foreshocks, which is in contrast to Earth's bow shock. Fluctuations downstream of quasi-parallel shocks tend to have larger amplitudes than waves downstream of quasi-perpendicular shocks. Proton foreshocks of shocks driven by stream interactions have extensions dr {<=}0.05 AU. This is smaller than foreshock extensions for ICME driven shocks. The difference in foreshock extensions is related to the fact that ICME driven shocks are formed closer to the Sun and therefore begin to accelerate particles very early in their existence, while stream interaction shocks form at {approx}1 AU and have been producing suprathermal particles for a shorter time.

  9. Teleconnected food supply shocks

    Science.gov (United States)

    Bren d'Amour, Christopher; Wenz, Leonie; Kalkuhl, Matthias; Steckel, Jan Christoph; Creutzig, Felix

    2016-03-01

    The 2008-2010 food crisis might have been a harbinger of fundamental climate-induced food crises with geopolitical implications. Heat-wave-induced yield losses in Russia and resulting export restrictions led to increases in market prices for wheat across the Middle East, likely contributing to the Arab Spring. With ongoing climate change, temperatures and temperature variability will rise, leading to higher uncertainty in yields for major nutritional crops. Here we investigate which countries are most vulnerable to teleconnected supply-shocks, i.e. where diets strongly rely on the import of wheat, maize, or rice, and where a large share of the population is living in poverty. We find that the Middle East is most sensitive to teleconnected supply shocks in wheat, Central America to supply shocks in maize, and Western Africa to supply shocks in rice. Weighing with poverty levels, Sub-Saharan Africa is most affected. Altogether, a simultaneous 10% reduction in exports of wheat, rice, and maize would reduce caloric intake of 55 million people living in poverty by about 5%. Export bans in major producing regions would put up to 200 million people below the poverty line at risk, 90% of which live in Sub-Saharan Africa. Our results suggest that a region-specific combination of national increases in agricultural productivity and diversification of trade partners and diets can effectively decrease future food security risks.

  10. Early Treatment in Shock

    Science.gov (United States)

    2011-06-01

    of L-arginine resuscitation in shock were carried out by An-1 gele , Chaudry, and co-workers. 6-10 They used the rat model, bleeding to 40 mm Hg in...17 14. Preissler G, Lothe F, Ebersberger U, Huff I, Bittmann I, Messmer K, Jauch KW, An-18 gele , MK. Recipient treatment with L-arginine

  11. A Shocking New Pump

    Science.gov (United States)

    2000-01-01

    Hydro Dynamics, Inc. received a technical helping hand from NASA that made their Hydrosonic Pump (HPump) a reality. Marshall engineers resolved a bearing problem in the rotor of the pump and recommended new bearings, housings and mounting hardware as a solution. The resulting HPump is able to heat liquids with greater energy efficiency using shock waves to generate heat.

  12. Planetary Bow Shocks

    CERN Document Server

    Treumann, R A

    2008-01-01

    Our present knowledge of the properties of the various planetary bow shocks is briefly reviewed. We do not follow the astronomical ordering of the planets. We rather distinguish between magnetised and unmagnetised planets which groups Mercury and Earth with the outer giant planets of the solar system, Mars and Moon in a separate group lacking magnetic fields and dense atmospheres, and Venus together with the comets as the atmospheric celestial objects exposed to the solar wind. Asteroids would, in this classification, fall into the group together with the Moon and should behave similarly though being much smaller. Extrasolar planets are not considered as we have only remote information about their behaviour. The presentation is brief in the sense that our in situ knowledge is rather sporadic yet, depending on just a countable number of bow shock crossings from which just some basic conclusions can be drawn about size, stationarity, shape and nature of the respective shock. The only bow shock of which we have ...

  13. Shock compression of nitrobenzene

    Science.gov (United States)

    Kozu, Naoshi; Arai, Mitsuru; Tamura, Masamitsu; Fujihisa, Hiroshi; Aoki, Katsutoshi; Yoshida, Masatake; Kondo, Ken-Ichi

    1999-06-01

    The Hugoniot (4 - 30 GPa) and the isotherm (1 - 7 GPa) of nitrobenzene have been investigated by shock and static compression experiments. Nitrobenzene has the most basic structure of nitro aromatic compounds, which are widely used as energetic materials, but nitrobenzene has been considered not to explode in spite of the fact its calculated heat of detonation is similar to TNT, about 1 kcal/g. Explosive plane-wave generators and diamond anvil cell were used for shock and static compression, respectively. The obtained Hugoniot consists of two linear lines, and the kink exists around 10 GPa. The upper line agrees well with the Hugoniot of detonation products calculated by KHT code, so it is expected that nitrobenzene detonates in that area. Nitrobenzene solidifies under 1 GPa of static compression, and the isotherm of solid nitrobenzene was obtained by X-ray diffraction technique. Comparing the Hugoniot and the isotherm, nitrobenzene is in liquid phase under experimented shock condition. From the expected phase diagram, shocked nitrobenzene seems to remain metastable liquid in solid phase region on that diagram.

  14. Toxic shock syndrome

    Science.gov (United States)

    ... chap 196. Read More Acute kidney failure Heart failure - overview Shock Review Date 4/12/2016 Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department ...

  15. Health Shocks and Retirement:

    DEFF Research Database (Denmark)

    Datta Gupta, Nabanita; Larsen, Mona

    benefits in Denmark nor by the promotion of corporate social responsibility initiatives since the mid-1990s. In the late 1990s, however, the retirement rate following a health shock is reduced to 3% with the introduction of the subsidized employment program (fleksjob) but this effect is not strongly...

  16. Repetition priming in selective attention: A TVA analysis.

    Science.gov (United States)

    Ásgeirsson, Árni Gunnar; Kristjánsson, Árni; Bundesen, Claus

    2015-09-01

    Current behavior is influenced by events in the recent past. In visual attention, this is expressed in many variations of priming effects. Here, we investigate color priming in a brief exposure digit-recognition task. Observers performed a masked odd-one-out singleton recognition task where the target-color either repeated or changed between subsequent trials. Performance was measured by recognition accuracy over exposure durations. The purpose of the study was to replicate earlier findings of perceptual priming in brief displays and to model those results based on a Theory of Visual Attention (TVA; Bundesen, 1990). We tested 4 different definitions of a generic TVA-model and assessed their explanatory power. Our hypothesis was that priming effects could be explained by selective mechanisms, and that target-color repetitions would only affect the selectivity parameter (α) of our models. Repeating target colors enhanced performance for all 12 observers. As predicted, this was only true under conditions that required selection of a target among distractors, but not when a target was presented alone. Model fits by TVA were obtained with a trial-by-trial maximum likelihood estimation procedure that estimated 4-15 free parameters, depending on the particular model. We draw two main conclusions. Color priming can be modeled simply as a change in selectivity between conditions of repetition or swap of target color. Depending on the desired resolution of analysis; priming can accurately be modeled by a simple four parameter model, where VSTM capacity and spatial biases of attention are ignored, or more fine-grained by a 10 parameter model that takes these aspects into account. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. In situ local shock speed and transit shock speed

    Directory of Open Access Journals (Sweden)

    S. Watari

    Full Text Available A useful index for estimating the transit speeds was derived by analyzing interplanetary shock observations. This index is the ratio of the in situ local shock speed and the transit speed; it is 0.6–0.9 for most observed shocks. The local shock speed and the transit speed calculated for the results of the magnetohydrodynamic simulation show good agreement with the observations. The relation expressed by the index is well explained by a simplified propagation model assuming a blast wave. For several shocks the ratio is approximately 1.2, implying that these shocks accelerated during propagation in slow-speed solar wind. This ratio is similar to that for the background solar wind acceleration.

    Keywords. Interplanetary physics (Flare and stream dynamics; Interplanetary shocks; Solar wind plasma

  18. Shock Dynamics in Stellar Outbursts. I. Shock Formation

    Science.gov (United States)

    Ro, Stephen; Matzner, Christopher D.

    2017-05-01

    Wave-driven outflows and non-disruptive explosions have been implicated in pre-supernova outbursts, supernova impostors, luminous blue variable eruptions, and some narrow-line and superluminous supernovae. To model these events, we investigate the dynamics of stars set in motion by strong acoustic pulses and wave trains, focusing on nonlinear wave propagation, shock formation, and an early phase of the development of a weak shock. We identify the shock formation radius, showing that a heuristic estimate based on crossing characteristics matches an exact expansion around the wave front and verifying both with numerical experiments. Our general analytical condition for shock formation applies to one-dimensional motions within any static environment, including both eruptions and implosions. We also consider the early phase of shock energy dissipation. We find that waves of super-Eddington acoustic luminosity always create shocks, rather than damping by radiative diffusion. Therefore, shock formation is integral to super-Eddington outbursts.

  19. Initial Validation of Ballistic Shock Transducers

    Science.gov (United States)

    2017-06-05

    to 100 mega samples per second with at least 12 bit resolution is required. (2) Must be able to provide usable data output for post-test...measurement of shock, and this TOP will focus only on accelerometers. Engineering judgement can be used to adapt portions of the TOP to various other...LDV. Each was sampled at 5 MHz and digitally filtered at 100 kHz. This process should be repeated until all test levels are met. Figure 18

  20. Iconicity in Discourse: The Case of Repetition in Japanese.

    Science.gov (United States)

    Ishikawa, Minako

    This analysis of repeated utterances in Japanese conversational discourse focuses on repetition as an expression of iconicity. In the analysis of a 30-minute conversation among 4 Japanese speakers, the iconic meanings expressed by both reduplication and conversational repetition are highlighted. The iconicity characteristic of conversational data…

  1. Evidence-Based Behavioral Interventions for Repetitive Behaviors in Autism

    Science.gov (United States)

    Boyd, Brian A.; McDonough, Stephen G.; Bodfish, James W.

    2012-01-01

    Restricted and repetitive behaviors (RRBs) are a core symptom of autism spectrum disorders (ASD). There has been an increased research emphasis on repetitive behaviors; however, this research primarily has focused on phenomenology and mechanisms. Thus, the knowledge base on interventions is lagging behind other areas of research. The literature…

  2. Visual attention to advertising : The impact of motivation and repetition

    NARCIS (Netherlands)

    Pieters, RGM; Rosbergen, E; Hartog, M; Corfman, KP; Lynch, JG

    1996-01-01

    Using eye-tracking data, we examine the impact of motivation and repetition on visual attention to advertisements differing in argument quality. Our analyses indicate that repetition leads to an overall decrease in the amount of attention. However, while at first high motivation subjects attend to t

  3. On the Functions of Lexical Repetition in English Texts

    Institute of Scientific and Technical Information of China (English)

    XIAO Fuliang

    2016-01-01

    Lexical repetition, as a cohesive device of an English text, can help make up a cohesive and coherent text. Therefore, in English textual learning, it is helpful for students to know about different patterns and functions of lexical repetition to improve their English level and ability.

  4. Electric foot shock stress: a useful tool in neuropsychiatric studies.

    Science.gov (United States)

    Bali, Anjana; Jaggi, Amteshwar Singh

    2015-01-01

    Electric foot shock is a complex stressor with both physical and emotional components. It has been employed as an important tool to develop diverse animal models in the field of psychopharmacology. The electric foot shock paradigm includes acute or chronic exposures of shocks of varying intensity and duration on an electrified grid floor in an electric foot shock apparatus. Research evidence reveals that foot shocks of varying intensity produce behavioral and neurochemical changes reflecting depression, anxiety, and post-traumatic stress disorder (PTSD) in humans. Animals generally do not habituate to foot shocks in comparison to other stressors, including loud noise, bright light, and hot and cold temperatures. Additionally, it offers an experimental advantage of control over intensity and duration; therefore, by varying its application parameters, different disorder models have been created. Electric foot shock fear conditioning-induced ultrasonic vocalization and fear-potentiated startle have been explored to develop models of anxiety and panic. Similarly, fear conditioning in the form of foot shock exposure followed by situational reminders has been used to develop a model of PTSD. Electric foot shock-induced conflict has been explored to develop operant conflict models (Geller-Seifter and Vogel tests), which in turn are pharmacologically validated to screen potential anti-anxiety agents. Inescapable electric shock-induced 'learned helplessness' mimics the symptomology of depression, and this phenomenon has been employed to develop the model of depression. The present review describes the pharmacologically validated models of anxiety, depression, and PTSD involving electric foot shock as an aversive stimulus.

  5. Shock induced porous barrier flows, with underlying wall pressure amplification

    Science.gov (United States)

    Skews, B. W.; Bugarin, S.

    The flow field resulting from the impact of a shock wave on a variety of sheets of permeable material is studied. Earlier studies examined the flow through stationary sheets. It has, however, been found that if the sheet is placed a short distance in front of a surface, and can move under the shock loading, the pressure on the surface is amplified following shock impact, compared to the pressures that would be experienced with no covering. An important application to consider is the effect that textile clothing may have on a persons body when exposed to a blast environment. Single and multiple layers of a range of textiles have been tested. It was established that the heavier, more impermeable textiles such as Kevlar can amplify the shock wave pressure by as much as 400%. Experiments were also done with the textiles placed at an angle to the incoming shock wave and the mechanism for the amplification established through schlieren photography and pressure measurements.

  6. Experimental investigation of damping force of twin tube shock absorber

    Directory of Open Access Journals (Sweden)

    Sandip K. Kadu

    2014-09-01

    Full Text Available A shock absorber is a mechanical device to damp shock impulse and convert kinetic energy into thermal energy. The damping effect of shock absorber depends on damping force and damping force is affected by various process parameters. In this analysis three process parameters damping diameter(A, number of holes(B and suspension velocity(C were considered and their effect on damping force of shock absorber was studied and accordingly suitable orthogonal array was selected by taguchi method. Experiment conducted on servo hydraulic testing machine and after conducting experiments damping force was measured and with the help of S/N ratio, ANOVA, Regression analysis optimum parameter values can be obtained and confirmation experiments was carried out. Twin tube shock absorber was used to carry out experimentation.

  7. Refractive index of K9 Glass under Shock Loading

    Science.gov (United States)

    Hu, Changming; Wang, Xiang; Cai, Lingcang; Liu, Cangli

    2013-06-01

    We study K9 glass refraction index under shock loading conducted on powder gun,all experimental tests are plate impact loading. The impact veceloty range from 300m/s to 1200m/s, and the measure method is laser interferometer Photon Doppler Velocimetry(PDV) to measure the particle velocity both at the impact interface and free surface, The shock pressure from 2 GPa to 8 GPa, values for refraction are found from velocity corrections that must be made to account for refraction-index changes in the K9 glass due to shock wave motion. Experiment results show that refraction-index of K9 glass changes with the shock pressure in line relations, it can be as measure window to study the interesting materials under 10 GPa during the shock loading.

  8. Shock detachment from curved wedges

    Science.gov (United States)

    Mölder, S.

    2017-03-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  9. Shock detachment from curved wedges

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  10. Repetitive DNA Sequences in Wheat and Its Relatives

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-yong; LI Da-yong

    2001-01-01

    Repetitive DNA sequences form a large portion of eukaryote genomes. Using wheat ( Triticum )as a model, the classification, features and functions of repetitive DNA sequences in the Tritieeae grass tribe is reviewed as well as the role of these sequences in genome differentiation, control and regulation of homologous chromosome synapsis and pairing. Transposable elements, as an important portion of dispersed repetitives,may play an essential role in gene mutation of the host. Dynamic models for change of copy number and sequences of the repetitive family are also presented after the models of Charlesworth et al. Application of repetitive DNA sequences in the study of evolution, chromosome fingerprinting and marker assisted gene transfer and breeding are described by taking wheat as an example.

  11. Nonword Repetition and Speech Motor Control in Children

    Directory of Open Access Journals (Sweden)

    Christina Reuterskiöld

    2015-01-01

    Full Text Available This study examined how familiarity of word structures influenced articulatory control in children and adolescents during repetition of real words (RWs and nonwords (NWs. A passive reflective marker system was used to track articulator movement. Measures of accuracy were obtained during repetition of RWs and NWs, and kinematic analysis of movement duration and variability was conducted. Participants showed greater consonant and vowel accuracy during RW than NW repetition. Jaw movement duration was longer in NWs compared to RWs across age groups, and younger children produced utterances with longer jaw movement duration compared to older children. Jaw movement variability was consistently greater during repetition of NWs than RWs in both groups of participants. The results indicate that increases in phonological short-term memory demands affect articulator movement. This effect is most pronounced in younger children. A range of skills may develop during childhood, which supports NW repetition skills.

  12. Transgenerational effects of environmental enrichment on repetitive motor behavior development.

    Science.gov (United States)

    Bechard, Allison R; Lewis, Mark H

    2016-07-01

    The favorable consequences of environmental enrichment (EE) on brain and behavior development are well documented. Much less is known, however, about transgenerational benefits of EE on non-enriched offspring. We explored whether transgenerational effects of EE might extend to the development of repetitive motor behaviors in deer mice. Repetitive motor behaviors are invariant patterns of movement that, across species, can be reduced by EE. We found that EE not only attenuated the development of repetitive behavior in dams, but also in their non-enriched offspring. Moreover, maternal behavior did not seem to mediate the transgenerational effect we found, although repetitive behavior was affected by reproductive experience. These data support a beneficial transgenerational effect of EE on repetitive behavior development and suggest a novel benefit of reproductive experience.

  13. Repetition and Emotive Communication in Music Versus Speech

    Directory of Open Access Journals (Sweden)

    Elizabeth Hellmuth eMargulis

    2013-04-01

    Full Text Available Music and speech are often placed alongside one another as comparative cases. Their relative overlaps and disassociations have been well explored (e.g. Patel, 2010. But one key attribute distinguishing these two domains has often been overlooked: the greater preponderance of repetition in music in comparison to speech. Recent fMRI studies have shown that familiarity – achieved through repetition – is a critical component of emotional engagement with music (Pereira et al., 2011. If repetition is fundamental to emotional responses to music, and repetition is a key distinguisher between the domains of music and speech, then close examination of the phenomenon of repetition might help clarify the ways that music elicits emotion differently than speech.

  14. Design, Simulation and Fabrication of Triaxial MEMS High Shock Accelerometer.

    Science.gov (United States)

    Zhang, Zhenhai; Shi, Zhiguo; Yang, Zhan; Xie, Zhihong; Zhang, Donghong; Cai, De; Li, Kejie; Shen, Yajing

    2015-04-01

    On the basis of analyzing the disadvantage of other structural accelerometer, three-axis high g MEMS piezoresistive accelerometer was put forward in order to apply to the high-shock test field. The accelerometer's structure and working principle were discussed in details. The simulation results show that three-axis high shock MEMS accelerometer can bear high shock. After bearing high shock impact in high-shock shooting test, three-axis high shock MEMS accelerometer can obtain the intact metrical information of the penetration process and still guarantee the accurate precision of measurement in high shock load range, so we can not only analyze the law of stress wave spreading and the penetration rule of the penetration process of the body of the missile, but also furnish the testing technology of the burst point controlling. The accelerometer has far-ranging application in recording the typical data that projectile penetrating hard target and furnish both technology guarantees for penetration rule and defend engineering.

  15. 五次坐立试验在慢性阻塞性肺疾病患者下肢功能评估中的初步应用%The preliminary application of five repetition sit-to-stand test for evaluating lower limb function in the patients with chronic obstructive pulmonary disease

    Institute of Scientific and Technical Information of China (English)

    陈奕; 钮美娥; 钱红英; 张秀琴

    2016-01-01

    Objective To determine the value of five repetition sit-to-stand test (FTSST) to evaluate lower limb function in the patients with chronic obstructive pulmonary disease (COPD).Methods Sixty-one patients with COPD were tested for FTSST,isokinetic testing muscle strength for lower limb,6-minute walking test.The relationship between FTSST time and muscle strength,6-minute walking test distance (6MWD) were analyzed.Results FTSST time was (7.86±2.21) s,extensor peak torque was (67.58± 24.83) Nm,extensor relative peak torque was 0.95(0.46) Nm/kg,6MWD was (444.05±112.53) m.FTSST time related to extensor peak torque,extensor relative peak torque,6MWD and types of complication,correlation coefficient values were-0.303,-0.393,-0.428,F =2.813,P < 0.05.Multivariate linear regression analysis showed that when the dependent variable was FTSST time,the variables of the equation were 6MWD and types of complication.Conclusions FTSST can be used for the rapid evaluation of lower extremity function in patients with COPD.The lower limb function gets worse,the FTSST time will be longer.Nursing staff should pay more attention to the lower limb function of patients with COPD,along with complications,using FTSST to evaluate lower extremity function.%目的 探讨5次坐立试验(FTSST)应用于慢性阻塞性肺疾病(COPD)患者下肢功能评估的有效性.方法 对61例COPD患者进行FTSST、下肢等速肌力测试、6 min步行试验的评价,分析FTSST时间与肌力、6min步行试验距离(6MWD)的相关性.结果 FTSST时间为(7.86±2.21)s,伸肌峰力矩为(67.58±24.83) Nm,伸肌相对峰力矩为0.95(0.46) Nm/kg,6MWD为(444.05±112.53) m;FTSST时间与伸肌峰力矩、伸肌相对峰力矩、6MWD、合并症种类相关(r=-0.303、-0.393、-0.428,F=2.813,P<0.05);以FTSST时间为因变量,进行多元线性回归分析,进入方程的变量是6MWD、合并症种类.结论 FTSST可用于COPD患者下肢功能的快速评估,且FTSST时间越长,下肢功能越差;

  16. Shock metamorphism of deformed quartz

    Science.gov (United States)

    Gratz, Andrew J.; Christie, John; Tyburczy, James; Ahrens, Thomas; Pongratz, Peter

    1988-01-01

    The effect produced by shock loading (to peak pressures of 12 and 24) on deformed synthetic quartz containing a dislocation and abundant bubbles and small inclusions was investigated, and the relationships between preexisting dislocation density shock lamellae in the target material were examined. The resultant material was found to be inhomogeneously deformed and extremely fractured. Results of TEM examinations indicate that no change in dislocation density was caused by shock loading except in regions containing shock lamellae, where the dislocation density was lowered. The shock-induced defects tend to nucleate on and be controlled by preexisting stress concentrators; shock lamellae, glassy veins, and most curviplanar defects form in tension, presumably during release. An extremely mobile silica fluid is formed and injected into fractures during release, which forcibly removes crystalline fragments from vein walls. It is concluded that shock deformation in quartz is dominated by fracture and melting.

  17. Bubble Dynamics and Shock Waves

    CERN Document Server

    2013-01-01

    This volume of the Shock Wave Science and Technology Reference Library is concerned with the interplay between bubble dynamics and shock waves. It is divided into four parts containing twelve chapters written by eminent scientists. Topics discussed include shock wave emission by laser generated bubbles (W Lauterborn, A Vogel), pulsating bubbles near boundaries (DM Leppinen, QX Wang, JR Blake), interaction of shock waves with bubble clouds (CD Ohl, SW Ohl), shock propagation in polydispersed bubbly liquids by model equations (K Ando, T Colonius, CE Brennen. T Yano, T Kanagawa,  M Watanabe, S Fujikawa) and by DNS (G Tryggvason, S Dabiri), shocks in cavitating flows (NA Adams, SJ Schmidt, CF Delale, GH Schnerr, S Pasinlioglu) together with applications involving encapsulated bubble dynamics in imaging (AA Doinikov, A Novell, JM Escoffre, A Bouakaz),  shock wave lithotripsy (P Zhong), sterilization of ships’ ballast water (A Abe, H Mimura) and bubbly flow model of volcano eruptions ((VK Kedrinskii, K Takayama...

  18. The Entamoeba histolytica methylated LINE-binding protein EhMLBP provides protection against heat shock.

    Science.gov (United States)

    Katz, Sophia; Kushnir, Oded; Tovy, Ayala; Siman Tov, Rama; Ankri, Serge

    2012-01-01

    Adaptation to environmental stress is a key process that allows the unicellular parasite Entamoeba histolytica to survive in its human host. We previously characterized EhMLBP as an essential protein for the growth and the virulence of the parasite. EhMLBP binds to methylated repetitive DNA, and is one of the core proteins of the parasite's epigenetic machinery. Here, we show that EhMLBP and heat shock proteins have common properties. EhMLBP is induced by heat shock and its expression is regulated by a heat shock element binding site that is located in its 5' non-coding region. Following heat shock, the perinuclear localization of EhMLBP in control trophozoites is replaced by an even distribution within the nucleus alongside with an enhanced recruitment of EhMLBP to the reverse transcriptase of a long interspersed nucleotide element (LINE) DNA. Constitutive overexpression of EhMLBP protects trophozoites against heat shock and reduces protein aggregation. This protective function is lost in trophozoites that overexpress a mutated form of EhMLBP which is devoid of its heat shock domain. To the best of our knowledge, this is the first report of a methyl DNA-binding protein that plays a protective role against heat shock.

  19. Probing combustion chemistry in a miniature shock tube with synchrotron VUV photo ionization mass spectrometry.

    Science.gov (United States)

    Lynch, Patrick T; Troy, Tyler P; Ahmed, Musahid; Tranter, Robert S

    2015-02-17

    Tunable synchrotron-sourced photoionization time-of-flight mass spectrometry (PI-TOF-MS) is an important technique in combustion chemistry, complementing lab-scale electron impact and laser photoionization studies for a wide variety of reactors, typically at low pressure. For high-temperature and high-pressure chemical kinetics studies, the shock tube is the reactor of choice. Extending the benefits of shock tube/TOF-MS research to include synchrotron sourced PI-TOF-MS required a radical reconception of the shock tube. An automated, miniature, high-repetition-rate shock tube was developed and can be used to study high-pressure reactive systems (T > 600 K, P shock waves. In this paper, we present results of a PI-TOF-MS study at the Advanced Light Source at Lawrence Berkeley National Laboratory. Dimethyl ether pyrolysis (2% CH3OCH3/Ar) was observed behind the reflected shock (1400 shock tube studies. The signal levels attained and data throughput rates with this technique are comparable to those with other synchrotron-based PI-TOF-MS reactors, and it is anticipated that this high pressure technique will greatly complement those lower pressure techniques.

  20. Development of a thermal fatigue test method for thermal barrier coatings by laser excitation using a laser thermal shock facility; Entwicklung eines Pruefverfahrens zur laserinduzierten thermischen Ermuedung thermischer Schutzschichten mittels einer Laser-Thermoschockpruefeinrichtung

    Energy Technology Data Exchange (ETDEWEB)

    Nies, Daniel

    2012-07-13

    The finite nature of fossil fuel supply and the growing environmental awareness become increasingly stronger motivations for the development of efficient gas turbines and jet engines for power generation or as engines for land-, sea- and water-based vehicles. One concept developed for this purpose are thermal barrier coatings, where the thermal load of components is reduced by applying a ceramic coating onto the components. In this work the possibility to use a laser thermal shock facility for thermo-cyclic testing of thermal barrier coatings is examined. A focused laser beam is used for heating the sample and a homogeneous temperature distribution on the sample surface is achieved by the used trajectory and radial adjusted laser power. The required improvements of the existing testing facility are explained, including the development of a new sample holder and of the testing and evaluation routines for the experiments. For the assessment of the initiation and evolution of damages, acoustic emission and thermographic methods are used. The possibilities and limits of these methods are assessed during the experiments. The work also includes an extensive temperature dependent characterisation of the ceramic material used for the thermal barrier coating. In this part, the measurement of the Young's modulus by a dynamic method is to be highlighted, as this is a rarely used technique. The characterisations show the expected values, except for a lower porosity as expected by the manufacturer and no significant phase changes during isothermal heat treatments. To reach sample surface temperatures above 1000 C, it is necessary to increase the absorption by an additional coating of magnetite. The temperature distribution on the surface is measured by an infrared camera, which is calibrated for this purpose. With the incorporated active air cooling of the sample backside, the temperature gradient can be controlled, but still leaves room for improvements. Already without

  1. Generation of low-timing-jitter femtosecond pulse trains with 2 GHz repetition rate via external repetition rate multiplication.

    Science.gov (United States)

    Chen, Jian; Sickler, Jason W; Fendel, Peter; Ippen, Erich P; Kärtner, Franz X; Wilken, Tobias; Holzwarth, Ronald; Hänsch, Theodor W

    2008-05-01

    Generation of low-timing-jitter 150 fs pulse trains at 1560 nm with 2 GHz repetition rate is demonstrated by locking a 200 MHz fundamental polarization additive-pulse mode-locked erbium fiber laser to high-finesse external Fabry-Perot cavities. The timing jitter and relative intensity noise of the repetition-rate multiplied pulse train are investigated.

  2. Temporal Dynamics of Repetitions during the Early Stage of Stuttering: An Acoustic Study

    Directory of Open Access Journals (Sweden)

    Tara. V.K

    2011-01-01

    Full Text Available The purpose of this study is to compare the duration characteristic of sound repetitions in the speech of adults who stutter (S=10 recorded near the onset of their stuttering to those of controlled nonstuttering adults (C=10. Dysfluent episodes are identified in digital recordings of the clients read speech. The digitized signals are analyzed by means of Cool Edit Pro software. Using visual displays of sound spectrograms, the durations of the spoken repetition units, the silent intervals between the units and the total dysfluency are measured. The stutterers exhibit shorter silent intervals between spoken repetitions units, which is used as one of the parameter for objective assessment of early stuttering. The total duration of the stutterer’s dysfluency is significantly shorter because of their shorter silent intervals when compared to dysfluency of equal repetition units produced by control subjects. Analysis reveal that silent interval duration is capable of differentiating stuttering from control client with 77.4 - 95 % accuracy. In this work 80% of data are used for training and remaining 20% for testing.

  3. [Rehabilitation Using Repetitive Transcranial Magnetic Stimulation].

    Science.gov (United States)

    Takeuchi, Naoyuki; Izumi, Shin-Ichi

    2017-03-01

    Various novel stroke rehabilitative methods have been developed based on findings in basic science and clinical research. Recently, many reports have shown that repetitive transcranial magnetic stimulation (rTMS) improves function in stroke patients by altering the excitability of the human cortex. The interhemispheric competition model proposes that deficits in stroke patients are due to reduced output from the affected hemisphere and excessive interhemispheric inhibition from the unaffected hemisphere to the affected hemisphere. The interhemispheric competition model indicates that improvement in deficits can be achieved either by increasing the excitability of the affected hemisphere using excitatory rTMS or by decreasing the excitability of the unaffected hemisphere using inhibitory rTMS. Recovery after stroke is related to neural plasticity, which involves developing new neural connections, acquiring new functions, and compensating for impairments. Artificially modulating the neural network by rTMS may induce a more suitable environment for use-dependent plasticity and also may interfere with maladaptive neural activation, which weakens function and limits recovery. There is potential, therefore, for rTMS to be used as an adjuvant therapy for developed neurorehabilitation techniques in stroke patients.

  4. Development of a repetitive compact torus injector

    Science.gov (United States)

    Onchi, Takumi; McColl, David; Dreval, Mykola; Rohollahi, Akbar; Xiao, Chijin; Hirose, Akira; Zushi, Hideki

    2013-10-01

    A system for Repetitive Compact Torus Injection (RCTI) has been developed at the University of Saskatchewan. CTI is a promising fuelling technology to directly fuel the core region of tokamak reactors. In addition to fuelling, CTI has also the potential for (a) optimization of density profile and thus bootstrap current and (b) momentum injection. For steady-state reactor operation, RCTI is necessary. The approach to RCTI is to charge a storage capacitor bank with a large capacitance and quickly charge the CT capacitor bank through a stack of integrated-gate bipolar transistors (IGBTs). When the CT bank is fully charged, the IGBT stack will be turned off to isolate banks, and CT formation/acceleration sequence will start. After formation of each CT, the fast bank will be replenished and a new CT will be formed and accelerated. Circuits for the formation and the acceleration in University of Saskatchewan CT Injector (USCTI) have been modified. Three CT shots at 10 Hz or eight shots at 1.7 Hz have been achieved. This work has been sponsored by the CRC and NSERC, Canada.

  5. REPETITION AS A SPECIAL TYPE OF SYNTACTIC RELATIONS IN REPRESENTED SPEECH: BASED ON THE PROSE BY MARINA TSVETAEVA

    Directory of Open Access Journals (Sweden)

    Olga Pavlovna Puchinina

    2017-03-01

    Full Text Available The author studies the peculiarities of repetition, being one of the ways to build syntactic relations in the represented speech structure, based on the prose by Marina Tsvetaeva. The article describes the different types of repetitions, their distinctive features and frequency of usage in the studied tests. The author describes different types of repetitions in the studied cases of represented speech from the point of view of their position. Repetition occurs at the beginning, end of sentences, beginning and end of a statement or paragraph, end of a statement and beginning of the next one; lexical items may be repeated in the middle of a statement. The morphology of repetitions, i.e., the way by what parts of speech the repeated words and structures are expressed, is of interest from the point of view of functional grammar. The author notes that Tsvetaeva repeats different parts of speech: conjunctions, prepositions, particles, nouns, pronouns, adverbs, numerals, verbs, modal words or a combination of two words. Moreover, due to her special intention, Tsvetaeva intensifies repetition through particular phonetic devices, such as alliteration, rhyme and rhythm, which make her prosaic works sound poetic. Purpose. The article is devoted to the topic of rendering another person’s speech, as it continues to be one of the most important issues of modern linguistics. The subject of analysis is repetition and its different types in the structure of represented speech on the material of prose texts by Marina Tsvetaeva. The author’s aims is to reveal the way these types of repetition (lexical, syntactic, semantic ones function in the structure of represented speech and what effect is achieved with their help. Methodology. The research has been conducted using the continuous sampling method and the quantitative estimation method, aimed to identify the frequency of using different types of repetition and repeated parts of speech and constructions in the

  6. Simulations of Relativistic Collisionless Shocks: Shock Structure and Particle Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Spitkovsky, Anatoly; /KIPAC, Menlo Park

    2006-04-10

    We discuss 3D simulations of relativistic collisionless shocks in electron-positron pair plasmas using the particle-in-cell (PIC) method. The shock structure is mainly controlled by the shock's magnetization (''sigma'' parameter). We demonstrate how the structure of the shock varies as a function of sigma for perpendicular shocks. At low magnetizations the shock is mediated mainly by the Weibel instability which generates transient magnetic fields that can exceed the initial field. At larger magnetizations the shock is dominated by magnetic reflections. We demonstrate where the transition occurs and argue that it is impossible to have very low magnetization collisionless shocks in nature (in more than one spatial dimension). We further discuss the acceleration properties of these shocks, and show that higher magnetization perpendicular shocks do not efficiently accelerate nonthermal particles in 3D. Among other astrophysical applications, this may pose a restriction on the structure and composition of gamma-ray bursts and pulsar wind outflows.

  7. A Simulation of the Effects of Varying Repetition Rate and Pulse Width of Nanosecond Discharges on Premixed Lean Methane-Air Combustion

    Directory of Open Access Journals (Sweden)

    Moon Soo Bak

    2012-01-01

    Full Text Available Two-dimensional kinetic simulation has been carried out to investigate the effects of repetition rate and pulse width of nanosecond repetitively pulsed discharges on stabilizing premixed lean methane-air combustion. The repetition rate and pulse width are varied from 10 kHz to 50 kHz and from 9 ns to 2 ns while the total power is kept constant. The lower repetition rates provide larger amounts of radicals such as O, H, and OH. However, the effect on stabilization is found to be the same for all of the tested repetition rates. The shorter pulse width is found to favor the production of species in higher electronic states, but the varying effects on stabilization are also found to be small. Our results indicate that the total deposited power is the critical element that determines the extent of stabilization over this range of discharge properties studied.

  8. Calidad de las espirometrías en un estudio epidemiológico de terreno: Factores determinantes de la necesidad de repetir el examen en el estudio Platino-Chile SPIROMETRIES IN A POPULATION BASED STUDY: FACTORS DETERMINING THE NEED OF TEST REPETITION, IN CHILE'S PLATINO STUDY

    Directory of Open Access Journals (Sweden)

    Marcela Araya B.

    2005-09-01

    study can be associated low quality spirometries in the first session: sex, age, socioeconomic level, educational level, body mass index, cold chill, smoking, operating technician, date and subject's previous spirometric experience. 1.168 individuals were evaluated with spirometry. Fifteen nurses and 1 midwife were trained according to NIOSCH standards. Easy One NDD spirometers were used. 1.037 subjects (88.8% performed a satisfactory spirometry in the first session, and 131 (11.2% failed to do so. Only two significant predictors of this failure were identified: age and educational level. Causes for test repetition were 1 Non satisfactory acceptability (77.1%; 2 lack of reproducibility (67.9%; 3 decline of post bronchodilator CVF without concomitant change in VEF1 (36.6%. Eighty nine of the 131 subjects accepted to repeat the test. A satisfactory spirometry was obtained in 79 subjects. Hence, at the end of the study 95.5 % of the subjects attained a satisfactory test. We conclude that personnel without experience, with appropriate training, can perform high quality field spirometries. Acceptability and repoducibility were the most sensitive factors associated with a bad performance of spirometry. Age and schooling were the main factors related with a low quality spirometry. No association was detected regarding technician as a predictor of low quality spirometries carried out in a population setting

  9. High Order Numerical Methods for LES of Turbulent Flows with Shocks

    Science.gov (United States)

    Kotov, D. V.; Yee, H. C.; Hadjadj, A.; Wray, A.; Sjögreen, B.

    2014-01-01

    Simulation of turbulent flows with shocks employing explicit subgrid-scale (SGS) filtering may encounter a loss of accuracy in the vicinity of a shock. In this work we perform a comparative study of different approaches to reduce this loss of accuracy within the framework of the dynamic Germano SGS model. One of the possible approaches is to apply Harten's subcell resolution procedure to locate and sharpen the shock, and to use a one-sided test filter at the grid points adjacent to the exact shock location. The other considered approach is local disabling of the SGS terms in the vicinity of the shock location. In this study we use a canonical shock-turbulence interaction problem for comparison of the considered modifications of the SGS filtering procedure. For the considered test case both approaches show a similar improvement in the accuracy near the shock.

  10. Desalination shocks in microstructures

    CERN Document Server

    Mani, Ali

    2011-01-01

    Salt transport in bulk electrolytes is limited by diffusion and convection, but in microstructures with charged surfaces (e.g. microfluidic devices, porous media, soils, or biological tissues) surface conduction and electro-osmotic flow also contribute to ionic fluxes. For small applied voltages, these effects lead to well known linear electrokinetic phenomena. In this paper, we predict some surprising nonlinear dynamics that can result from the competition between bulk and interfacial transport at higher voltages. When counter-ions are selectively removed by a membrane or electrode, a "desalination shock" can propagate through the microstructure, leaving in its wake an ultrapure solution, nearly devoid of co-ions and colloidal impurities. We elucidate the basic physics of desalination shocks and develop a mathematical theory of their existence, structure, and stability, allowing for slow variations in surface charge or channel geometry. Via asymptotic approximations and similarity solutions, we show that des...

  11. Bow shock data analysis

    Science.gov (United States)

    Zipf, Edward C.; Erdman, Peeter W.

    1994-08-01

    The University of Pittsburgh Space Physics Group in collaboration with the Army Research Office (ARO) modeling team has completed a systematic organization of the shock and plume spectral data and the electron temperature and density measurements obtained during the BowShock I and II rocket flights which have been submitted to the AEDC Data Center, has verified the presence of CO Cameron band emission during the Antares engine burn and for an extended period of time in the post-burn plume, and have adapted 3-D radiation entrapment codes developed by the University of Pittsburgh to study aurora and other atmospheric phenomena that involve significant spatial effects to investigate the vacuum ultraviolet (VUV) and extreme ultraviolet (EUV) envelope surrounding the re-entry that create an extensive plasma cloud by photoionization.

  12. SUPERDIFFUSIVE SHOCK ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    Perri, S.; Zimbardo, G. [Dipartimento di Fisica, Universita della Calabria, Ponte P. Bucci Cubo 31C, I-87036 Rende (Italy)

    2012-05-10

    The theory of diffusive shock acceleration is extended to the case of superdiffusive transport, i.e., when the mean square deviation grows proportionally to t{sup {alpha}}, with {alpha} > 1. Superdiffusion can be described by a statistical process called Levy random walk, in which the propagator is not a Gaussian but it exhibits power-law tails. By using the propagator appropriate for Levy random walk, it is found that the indices of energy spectra of particles are harder than those obtained where a normal diffusion is envisaged, with the spectral index decreasing with the increase of {alpha}. A new scaling for the acceleration time is also found, allowing substantially shorter times than in the case of normal diffusion. Within this framework we can explain a number of observations of flat spectra in various astrophysical and heliospheric contexts, for instance, for the Crab Nebula and the termination shock of the solar wind.

  13. Tailoring the Blast Exposure Conditions in the Shock Tube for Generating Pure, Primary Shock Waves: The End Plate Facilitates Elimination of Secondary Loading of the Specimen.

    Science.gov (United States)

    Kuriakose, Matthew; Skotak, Maciej; Misistia, Anthony; Kahali, Sudeepto; Sundaramurthy, Aravind; Chandra, Namas

    2016-01-01

    The end plate mounted at the mouth of the shock tube is a versatile and effective implement to control and mitigate the end effects. We have performed a series of measurements of incident shock wave velocities and overpressures followed by quantification of impulse values (integral of pressure in time domain) for four different end plate configurations (0.625, 2, 4 inches, and an open end). Shock wave characteristics were monitored by high response rate pressure sensors allocated in six positions along the length of 6 meters long 229 mm square cross section shock tube. Tests were performed at three shock wave intensities, which was controlled by varying the Mylar membrane thickness (0.02, 0.04 and 0.06 inch). The end reflector plate installed at the exit of the shock tube allows precise control over the intensity of reflected waves penetrating into the shock tube. At the optimized distance of the tube to end plate gap the secondary waves were entirely eliminated from the test section, which was confirmed by pressure sensor at T4 location. This is pronounced finding for implementation of pure primary blast wave animal model. These data also suggest only deep in the shock tube experimental conditions allow exposure to a single shock wave free of artifacts. Our results provide detailed insight into spatiotemporal dynamics of shock waves with Friedlander waveform generated using helium as a driver gas and propagating in the air inside medium sized tube. Diffusion of driver gas (helium) inside the shock tube was responsible for velocity increase of reflected shock waves. Numerical simulations combined with experimental data suggest the shock wave attenuation mechanism is simply the expansion of the internal pressure. In the absence of any other postulated shock wave decay mechanisms, which were not implemented in the model the agreement between theory and experimental data is excellent.

  14. Nonword repetition as a predictor of long-term speech and language skills in children with cochlear implants.

    Science.gov (United States)

    Casserly, Elizabeth D; Pisoni, David B

    2013-04-01

    The rapid phonological processing skills of children with cochlear implants early in life (ages 8-10), as measured by nonword repetition performance, will predict their language development 8 years later (ages 16-18). This core processing ability will also correlate with concurrent measures of language at both ages of testing. Understanding the causes of the wide range of performance in pediatric cochlear implant users currently constitutes a major barrier to clinical and research progress in the field. Research into children's neurocognitive abilities such as working memory capacity and verbal rehearsal speed, in addition to conventional demographic variables, has shown that these foundational skills play a key role in determining outcomes. Here, we investigate the impact of rapid phonological processing, an ability which is critical in spoken language use, for children with cochlear implants. Fifty-two deaf children with cochlear implants completed a battery of 14 clinical and research measures of language, neurocognitive, and nonword repetition skills in 2 testing sessions 8 years apart. Performance on the nonword repetition task at both testing sessions correlated significantly with concurrent language abilities. Importantly, nonword repetition accuracy at age 8 to 10 also significantly predicted performance on measures of language ability at age 16 to 18 in a wide range of domains, from speech intelligibility to sentence recognition in noise. These relations were significant even when other neurocognitive measures were controlled. Early nonword repetition performance in children with cochlear implants predicts later language development and, therefore, may identify those children at high risk for poor outcomes.

  15. Cutting edge: natural DNA repetitive extragenic sequences from gram-negative pathogens strongly stimulate TLR9.

    Science.gov (United States)

    Magnusson, Mattias; Tobes, Raquel; Sancho, Jaime; Pareja, Eduardo

    2007-07-01

    Bacterial DNA exerts immunostimulatory effects on mammalian cells via the intracellular TLR9. Although broad analysis of TLR9-mediated immunostimulatory potential of synthetic oligonucleotides has been developed, which kinds of natural bacterial DNA sequences are responsible for immunostimulation are not known. This work provides evidence that the natural DNA sequences named repetitive extragenic palindromic (REPs) sequences present in Gram-negative bacteria are able to produce innate immune system stimulation via TLR9. A strong induction of IFN-alpha production by REPs from Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, and Neisseria meningitidis was detected in splenocytes from 129 mice. In addition, the involvement of TLR9 in immune stimulation by REPs was confirmed using B6.129P2-Tlr9(tm1Aki) knockout mice. Considering the involvement of TLRs in Gram-negative septic shock, it is conceivable that REPs play a role in its pathogenesis. This study highlights REPs as a potential novel target in septic shock treatment.

  16. Shock breakout theory

    CERN Document Server

    Waxman, Eli

    2016-01-01

    The earliest supernova (SN) emission is produced when the optical depth of the plasma lying ahead of the shock, which ejects the envelope, drops below c/v, where v is the shock velocity. This "breakout" may occur when the shock reaches the edge of the star, producing a bright X-ray/UV flash on time scales of seconds to a fraction of an hour, followed by UV/optical "cooling" emission from the expanding cooling envelope on a day time-scale. If the optical depth of circumstellar material (CSM) ejected from the progenitor star prior to the explosion is larger than c/v, the breakout will take place at larger radii, within the CSM, extending its duration to days time scale. The properties of the early, breakout and cooling, emission carry unique signatures of the structure of the progenitor star (e.g. its radius and surface composition) and of its mass-loss history. The recent progress of wide-field transient surveys enable SN detections on a day time scale, and are being used to set unique constraints on the proge...

  17. The Stress Testing of Integrated Risk Based on Financial Asset Price Shocks%基于金融资产价格冲击的综合风险压力测试

    Institute of Scientific and Technical Information of China (English)

    袁芳英

    2014-01-01

    设计了一个整合流动性风险、信用风险和市场风险的宏观压力测试框架,分析金融资产价格冲击对银行体系的影响。应用蒙特卡罗方法模拟出各种金融资产价格冲击生成的市场风险路径,采用莫顿模型来分析银行的违约风险和市场风险的联系,同时也估计了违约风险和存款外流的关系,通过分析银行在银行间市场和资本市场的联系整合了传染性风险。在以上的理论分析框架下,用工行、建行、中国银行、农行和交行2008年的数据对我国银行体系进行了实证分析,其测试结果显示:银行体系的系统流动性风险很低,没有银行违约的概率是99.15%,说明整个银行体系是稳定的。实证分析的结果与2008年的实际情况相符,说明文章构建的压力测试理论框架是有效的。%In order to analyze the impact of financial asset price shocks on the banking system,this paper develops a macro stress-testing framework integrating liquidity risk, credit risk and market risk.Firstly,the Monte Carlo method is used to simulate market risk path generated by various types of financial asset price shocks.Secondly,the Morton model is used to analyze the relationship between market risks and default risks of banks, the relationship between default risks and deposit outflows is estimated as well, and contagion risk is also incorporated through analyzing banks' linkage in the interbank and capital markets.Finally,the above theoretical framework is applied to the Industrial and Commercial Bank of China,China Construction Bank,Bank of China,Agricultural Bank of China,and the Bank of Communications for empirical analysis on China's banking system,based on available data of 2008.The empirical result shows that the liquidity risk of the banking system is quite low,the probability of no bank defaulting is 99.15%,and the banking system is stable as a whole.The empirical finding is consistent with

  18. Repetitive energy transfer from an inductive energy store

    Energy Technology Data Exchange (ETDEWEB)

    Honig, E.M.

    1984-01-01

    The theoretical and experimental results of a research program aimed at finding practical ways to transfer energy repetitively from an inductive energy store to various loads are discussed. The objectives were to investigate and develop the high power opening switches and transfer circuits needed to enable high-repetition-rate operation of such systems, including a feasibility demonstration at a current level near 10 kA and a pulse repetition rate of 1-10 kpps with a 1-ohm load. The requirements of nonlinear, time-varying loads, such as the railgun electromagnetic launcher, were also addressed. Energy storage capability is needed for proper power conditioning in systems where the duty factor of the output pulse train is low. Inductive energy storage is attractive because it has both a high energy storage density and a fast discharge capability. By producing a pulse train with a peak power of 75 MW at a pulse repetition rate of 5 kpps in a one-ohm load system, this research program was the first to demonstrate fully-controlled, high-power, high-repetition-rate operation of an inductive energy storage and transfer system with survivable switches. Success was made possible by using triggered vacuum gap switches as repetitive, current-zero opening switches and developing several new repetitive transfer circuits using the counterpulse technique.

  19. Skill learning in mirror reading: how repetition determines acquisition.

    Science.gov (United States)

    Ofen-Noy, N; Dudai, Y; Karni, A

    2003-07-01

    Practice makes perfect, but the role of repetitions in skill learning is not yet fully understood. For example, given a similar number of trials on a given task, it is debated whether repeating and non-repeating items are learned by the same neural process. When one is given training with both types of items--does one learn two separate skills, or only one? Here we show, using a mirror reading task, that practice trials with trial-unique words, and practice trials with repeated words, count towards learning to a different degree. There was no interaction between the time-course of learning repeated and unique words even within the same individuals given mixed training. While repeated words were learned faster than unique words, the repetitions-dependent gains diminished with training beyond a small number of repetitions. Moreover, the gains in performance could not be accounted for solely by the number of repetitions, as assumed by power-law models of learning; rather, the passage of time was a critical factor. Finally, our results suggest that although both repeated and new words were learned by both declarative and procedural memory mechanisms, even a single repetition of specific words could lead to the establishment of a selective differential representation in memory. The results are compatible with the notion of a repetition-sensitive process, triggered by specific repeating events. This 'repetition counter' may be a critical trigger for the effective formation of procedural as well as some type of declarative memory.

  20. Radiative effects in radiative shocks in shock tubes

    Science.gov (United States)

    Drake, R. P.; Doss, F. W.; McClarren, R. G.; Adams, M. L.; Amato, N.; Bingham, D.; Chou, C. C.; DiStefano, C.; Fidkowski, K.; Fryxell, B.; Gombosi, T. I.; Grosskopf, M. J.; Holloway, J. P.; van der Holst, B.; Huntington, C. M.; Karni, S.; Krauland, C. M.; Kuranz, C. C.; Larsen, E.; van Leer, B.; Mallick, B.; Marion, D.; Martin, W.; Morel, J. E.; Myra, E. S.; Nair, V.; Powell, K. G.; Rauchwerger, L.; Roe, P.; Rutter, E.; Sokolov, I. V.; Stout, Q.; Torralva, B. R.; Toth, G.; Thornton, K.; Visco, A. J.

    2011-09-01

    Using modern high-energy-density facilities it is straightforward to produce radiative shock waves in which the transfer of energy by radiation controls the hydrodynamic structure of the system. Some of these experiments use shock tubes. This paper discusses such experiments, with an emphasis on the simple physical relations that determine the primary features of such shocks and on the details and impact of radiative energy transfer in such systems. Notable aspects include the creation of high-density shocked layers, the flow of radiative energy toward regions of higher energy density, and the creation of secondary shocks by ablation of the tube walls ahead of the primary shock front. Simulations of one such experimental system are also shown.

  1. Fundamentals of collisionless shocks for astrophysical application, 2. Relativistic shocks

    CERN Document Server

    Bykov, A M

    2011-01-01

    We review recent progress on collisionless relativistic shocks. Kinetic instability theory is briefed including its predictions and limitations. The main focus is on numerical experiments in (i) pair and (ii) electron-nucleon plasmas. The main results are: (i) confirmation of shock evolution in non-magnetised relativistic plasma in 3D due to either the lepton-Weibel instability or the ion-Weibel instability; (ii) sensitive dependence on upstream magnetisation ; (iii) the sensitive dependence of particle dynamics on the upstream magnetic inclination angle $\\thetabn$, where particles of $\\thetabn>34^\\circ$ cannot escape upstream, leading to the distinction between `sub-luminal' and `super-luminal' shocks; (iv) particles in ultra-relativistic shocks can hardly overturn the shock and escape to upstream; they may oscillate around the shock ramp for a long time, so to speak `surfing it' and thereby becoming accelerated by a kind of SDA; (v) these particles form a power law tail on the downstream distribution; their...

  2. Shock wave treatment in medicine

    Indian Academy of Sciences (India)

    S K Shrivastava; Kailash

    2005-03-01

    Extracorporeal shock wave therapy in orthopedics and traumatology is still a young therapy method. Since the last few years the development of shock wave therapy has progressed rapidly. Shock waves have changed the treatment of urolithiasis substantially. Today shock waves are the first choice to treat kidney and urethral stones. Urology has long been the only medical field for shock waves in medicine. Meanwhile shock waves have been used in orthopedics and traumatology to treat insertion tendinitis, avascular necrosis of the head of femur and other necrotic bone alterations. Another field of shock wave application is the treatment of tendons, ligaments and bones on horses in veterinary medicine. In the present paper we discuss the basic theory and application of shock waves and its history in medicine. The idea behind using shock wave therapy for orthopedic diseases is the stimulation of healing in tendons, surrounding tissue and bones. This is a completely different approach compared to urology where shock waves are used for disintegration.

  3. Explosively driven air blast in a conical shock tube

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Joel B., E-mail: joel.b.stewart2.civ@mail.mil; Pecora, Collin, E-mail: collin.r.pecora.civ@mail.mil [U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)

    2015-03-15

    Explosively driven shock tubes present challenges in terms of safety concerns and expensive upkeep of test facilities but provide more realistic approximations to the air blast resulting from free-field detonations than those provided by gas-driven shock tubes. Likewise, the geometry of conical shock tubes can naturally approximate a sector cut from a spherically symmetric blast, leading to a better agreement with the blast profiles of free-field detonations when compared to those provided by shock tubes employing constant cross sections. The work presented in this article documents the design, fabrication, and testing of an explosively driven conical shock tube whose goal was to closely replicate the blast profile seen from a larger, free-field detonation. By constraining the blast through a finite area, large blasts (which can add significant damage and safety constraints) can be simulated using smaller explosive charges. The experimental data presented herein show that a close approximation to the free-field air blast profile due to a 1.5 lb charge of C4 at 76 in. can be achieved by using a 0.032 lb charge in a 76-in.-long conical shock tube (which translates to an amplification factor of nearly 50). Modeling and simulation tools were used extensively in designing this shock tube to minimize expensive fabrication costs.

  4. Explosively driven air blast in a conical shock tube.

    Science.gov (United States)

    Stewart, Joel B; Pecora, Collin

    2015-03-01

    Explosively driven shock tubes present challenges in terms of safety concerns and expensive upkeep of test facilities but provide more realistic approximations to the air blast resulting from free-field detonations than those provided by gas-driven shock tubes. Likewise, the geometry of conical shock tubes can naturally approximate a sector cut from a spherically symmetric blast, leading to a better agreement with the blast profiles of free-field detonations when compared to those provided by shock tubes employing constant cross sections. The work presented in this article documents the design, fabrication, and testing of an explosively driven conical shock tube whose goal was to closely replicate the blast profile seen from a larger, free-field detonation. By constraining the blast through a finite area, large blasts (which can add significant damage and safety constraints) can be simulated using smaller explosive charges. The experimental data presented herein show that a close approximation to the free-field air blast profile due to a 1.5 lb charge of C4 at 76 in. can be achieved by using a 0.032 lb charge in a 76-in.-long conical shock tube (which translates to an amplification factor of nearly 50). Modeling and simulation tools were used extensively in designing this shock tube to minimize expensive fabrication costs.

  5. Heterogeneous nuclear ribonucleoprotein K inhibits heat shock-induced transcriptional activity of heat shock factor 1.

    Science.gov (United States)

    Kim, Hee-Jung; Lee, Jae-Jin; Cho, Jin-Hwan; Jeong, Jaeho; Park, A Young; Kang, Wonmo; Lee, Kong-Joo

    2017-08-04

    When cells are exposed to heat shock and various other stresses, heat shock factor 1 (HSF1) is activated, and the heat shock response (HSR) is elicited. To better understand the molecular regulation of the HSR, we used 2D-PAGE-based proteome analysis to screen for heat shock-induced post-translationally modified cellular proteins. Our analysis revealed that two protein spots typically present on 2D-PAGE gels and containing heterogeneous nuclear ribonucleoprotein K (hnRNP K) with trioxidized Cys(132) disappeared after the heat shock treatment and reappeared during recovery, but the total amount of hnRNP K protein remained unchanged. We next tested whether hnRNP K plays a role in HSR by regulating HSF1 and found that hnRNP K inhibits HSF1 activity, resulting in reduced expression of hsp70 and hsp27 mRNAs. hnRNP K also reduced binding affinity of HSF1 to the heat shock element by directly interacting with HSF1 but did not affect HSF1 phosphorylation-dependent activation or nuclear localization. hnRNP K lost its ability to induce these effects when its Cys(132) was substituted with Ser, Asp, or Glu. These findings suggest that hnRNP K inhibits transcriptional activity of HSF1 by inhibiting its binding to heat shock element and that the oxidation status of Cys(132) in hnRNP K is critical for this inhibition. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Directed PCR-free engineering of highly repetitive DNA sequences

    Directory of Open Access Journals (Sweden)

    Preissler Steffen

    2011-09-01

    Full Text Available Abstract Background Highly repetitive nucleotide sequences are commonly found in nature e.g. in telomeres, microsatellite DNA, polyadenine (poly(A tails of eukaryotic messenger RNA as well as in several inherited human disorders linked to trinucleotide repeat expansions in the genome. Therefore, studying repetitive sequences is of biological, biotechnological and medical relevance. However, cloning of such repetitive DNA sequences is challenging because specific PCR-based amplification is hampered by the lack of unique primer binding sites resulting in unspecific products. Results For the PCR-free generation of repetitive DNA sequences we used antiparallel oligonucleotides flanked by restriction sites of Type IIS endonucleases. The arrangement of recognition sites allowed for stepwise and seamless elongation of repetitive sequences. This facilitated the assembly of repetitive DNA segments and open reading frames encoding polypeptides with periodic amino acid sequences of any desired length. By this strategy we cloned a series of polyglutamine encoding sequences as well as highly repetitive polyadenine tracts. Such repetitive sequences can be used for diverse biotechnological applications. As an example, the polyglutamine sequences were expressed as His6-SUMO fusion proteins in Escherichia coli cells to study their aggregation behavior in vitro. The His6-SUMO moiety enabled affinity purification of the polyglutamine proteins, increased their solubility, and allowed controlled induction of the aggregation process. We successfully purified the fusions proteins and provide an example for their applicability in filter retardation assays. Conclusion Our seamless cloning strategy is PCR-free and allows the directed and efficient generation of highly repetitive DNA sequences of defined lengths by simple standard cloning procedures.

  7. Repetition-based Interactive Facade Modeling

    KAUST Repository

    AlHalawani, Sawsan

    2012-07-01

    Modeling and reconstruction of urban environments has gained researchers attention throughout the past few years. It spreads in a variety of directions across multiple disciplines such as image processing, computer graphics and computer vision as well as in architecture, geoscience and remote sensing. Having a virtual world of our real cities is very attractive in various directions such as entertainment, engineering, governments among many others. In this thesis, we address the problem of processing a single fa cade image to acquire useful information that can be utilized to manipulate the fa cade and generate variations of fa cade images which can be later used for buildings\\' texturing. Typical fa cade structures exhibit a rectilinear distribution where in windows and other elements are organized in a grid of horizontal and vertical repetitions of similar patterns. In the firt part of this thesis, we propose an efficient algorithm that exploits information obtained from a single image to identify the distribution grid of the dominant elements i.e. windows. This detection method is initially assisted with the user marking the dominant window followed by an automatic process for identifying its repeated instances which are used to define the structure grid. Given the distribution grid, we allow the user to interactively manipulate the fa cade by adding, deleting, resizing or repositioning the windows in order to generate new fa cade structures. Having the utility for the interactive fa cade is very valuable to create fa cade variations and generate new textures for building models. Ultimately, there is a wide range of interesting possibilities of interactions to be explored.

  8. Epithelial topography for repetitive tooth formation

    Directory of Open Access Journals (Sweden)

    Marcia Gaete

    2015-12-01

    Full Text Available During the formation of repetitive ectodermally derived organs such as mammary glands, lateral line and teeth, the tissue primordium iteratively initiates new structures. In the case of successional molar development, new teeth appear sequentially in the posterior region of the jaw from Sox2+ cells in association with the posterior aspect of a pre-existing tooth. The sequence of molar development is well known, however, the epithelial topography involved in the formation of a new tooth is unclear. Here, we have examined the morphology of the molar dental epithelium and its development at different stages in the mouse in vivo and in molar explants. Using regional lineage tracing we show that within the posterior tail of the first molar the primordium for the second and third molar are organized in a row, with the tail remaining in connection with the surface, where a furrow is observed. The morphology and Sox2 expression of the tail retains characteristics reminiscent of the earlier stages of tooth development, such that position along the A-P axes of the tail correlates with different temporal stages. Sox9, a stem/progenitor cell marker in other organs, is expressed mainly in the suprabasal epithelium complementary with Sox2 expression. This Sox2 and Sox9 expressing molar tail contains actively proliferating cells with mitosis following an apico-basal direction. Snail2, a transcription factor implicated in cell migration, is expressed at high levels in the tip of the molar tail while E-cadherin and laminin are decreased. In conclusion, our studies propose a model in which the epithelium of the molar tail can grow by posterior movement of epithelial cells followed by infolding and stratification involving a population of Sox2+/Sox9+ cells.

  9. Repetitive transcranial magnetic stimulation in psychiatry

    Directory of Open Access Journals (Sweden)

    Biswa Ranjan Mishra

    2011-01-01

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS is a non-invasive and relatively painless tool that has been used to study various cognitive functions as well as to understand the brain-behavior relationship in normal individuals as well as in those with various neuropsychiatric disorders. It has also been used as a therapeutic tool in various neuropsychiatric disorders because of its ability to specifically modulate distinct brain areas. Studies have shown that repeated stimulation at low frequency produces long-lasting inhibition, which is called as long-term depression, whereas repeated high-frequency stimulation can produce excitation through long-term potentiation. This paper reviews the current status of rTMS as an investigative and therapeutic modality in various neuropsychiatric disorders. It has been used to study the cortical and subcortical functions, neural plasticity and brain mapping in normal individuals and in various neuropsychiatric disorders. rTMS has been most promising in the treatment of depression, with an overall milder adverse effect profile compared with electroconvulsive therapy. In other neuropsychiatric disorders such as schizophrenia, mania, epilepsy and substance abuse, it has been found to be useful, although further studies are required to establish therapeutic efficacy. It appears to be ineffective in the treatment of obsessive compulsive disorder. There is a paucity of studies of efficacy and safety of rTMS in pediatric and geriatric population. Although it appears safe, further research is required to optimize its efficacy and reduce the side-effects. Magnetic seizure therapy, which involves producing seizures akin to electroconvulsive therapy, appears to be of comparable efficacy in the treatment of depression with less cognitive adverse effects.

  10. Clinical application of repetitive transcranial magnetic stimulation in stroke rehabilitation☆

    Science.gov (United States)

    Shin, Joonho; Yang, EunJoo; Cho, KyeHee; Barcenas, Carmelo L; Kim, Woo Jin; Min, Yusun; Paik, Nam-Jong

    2012-01-01

    Proper stimulation to affected cerebral hemisphere would promote the functional recovery of patients with stroke. Effects of repetitive transcranial magnetic stimulation on cortical excitability can be can be altered by the stimulation frequency, intensity and duration. There has been no consistent recognition regarding the best stimulation frequency and intensity. This study reviews the intervention effects of repetitive transcranial stimulation on motor impairment, dysphagia, visuospatial neglect and aphasia, and summarizes the stimulation frequency, intensity and area for repetitive transcranial magnetic stimulation to yield the best therapeutic effects. PMID:25745455

  11. Clinical application of repetitive transcranial magnetic stimulation in stroke rehabilitation

    Institute of Scientific and Technical Information of China (English)

    Joonho Shin; EunJoo Yang; KyeHee Cho; Carmelo L Barcenas; Woo Jin Kim; Yusun Min; Nam-Jong Paik

    2012-01-01

    Proper stimulation to affected cerebral hemisphere would promote the functional recovery of patients with stroke. Effects of repetitive transcranial magnetic stimulation on cortical excitability can be can be altered by the stimulation frequency, intensity and duration. There has been no consistent recognition regarding the best stimulation frequency and intensity. This study reviews the intervention effects of repetitive transcranial stimulation on motor impairment, dysphagia, visuospatial neglect and aphasia, and summarizes the stimulation frequency, intensity and area for repetitive transcranial magnetic stimulation to yield the best therapeutic effects.

  12. The Sandia MEMS passive shock sensor : FY07 maturation activities.

    Energy Technology Data Exchange (ETDEWEB)

    Houston, Jack E.; Blecke, Jill; Mitchell, John Anthony; Wittwer, Jonathan W.; Crowson, Douglas A.; Clemens, Rebecca C.; Walraven, Jeremy Allen; Epp, David S.; Baker, Michael Sean

    2008-08-01

    This report describes activities conducted in FY07 to mature the MEMS passive shock sensor. The first chapter of the report provides motivation and background on activities that are described in detail in later chapters. The second chapter discusses concepts that are important for integrating the MEMS passive shock sensor into a system. Following these two introductory chapters, the report details modeling and design efforts, packaging, failure analysis and testing and validation. At the end of FY07, the MEMS passive shock sensor was at TRL 4.

  13. Detonation Initiation by Annular Jets and Shock Waves

    Science.gov (United States)

    2007-11-02

    acquisition card and processed by a Labview program. 1. Diaphragm Selection for Shock Tube Several different diaphragms were used in the shock tube to vary...acquisition cards running in master-slave configuration and processed with a Labview program. Recording of the test section data acquisition system was...pa -1)E+ (-Y + 1) P5=1+ P2 I ½ -1+1 Pll + 2 - 1 + ( I + I)(M 2 (7) 1+7+1(2_ 1) Thus, the pressure ratio across the reflected shock wave can be found

  14. Comprehension priming as rational expectation for repetition: Evidence from syntactic processing.

    Science.gov (United States)

    Myslín, Mark; Levy, Roger

    2016-02-01

    Why do comprehenders process repeated stimuli more rapidly than novel stimuli? We consider an adaptive explanation for why such facilitation may be beneficial: priming is a consequence of expectation for repetition due to rational adaptation to the environment. If occurrences of a stimulus cluster in time, given one occurrence it is rational to expect a second occurrence closely following. Leveraging such knowledge may be particularly useful in online processing of language, where pervasive clustering may help comprehenders negotiate the considerable challenge of continual expectation update at multiple levels of linguistic structure and environmental variability. We test this account in the domain of structural priming in syntax, making use of the sentential complement-direct object (SC-DO) ambiguity. We first show that sentences containing SC continuations cluster in natural language, motivating an expectation for repetition of this structure. Second, we show that comprehenders are indeed sensitive to the syntactic clustering properties of their current environment. In a series of between-groups self-paced reading studies, we find that participants who are exposed to clusters of SC sentences subsequently process repetitions of SC structure more rapidly than participants who are exposed to the same number of SCs spaced in time, and attribute the difference to the learned degree of expectation for repetition. We model this behavior through Bayesian belief update, showing that (the optimal degree of) sensitivity to clustering properties of syntactic structures is indeed learnable through experience. Comprehension priming effects are thus consistent with rational expectation for repetition based on adaptation to the linguistic environment. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Effects of different rest intervals between antagonist paired sets on repetition performance and muscle activation.

    Science.gov (United States)

    Maia, Marianna F; Willardson, Jeffrey M; Paz, Gabriel A; Miranda, Humberto

    2014-09-01

    Recent evidence suggests that exercising the antagonist musculature acutely enhances subsequent performance for the agonist musculature. The purpose of this study was to examine the effects of different rest intervals between sets for exercises that involve antagonistic muscle groups, a technique referred to as antagonist paired sets (APS). Fifteen recreationally trained men were tested for knee extension (KE) exercise performance, with or without previous knee flexion (KF) exercise for the antagonist musculature. The following protocols were performed in random order with 10 repetition maximum loads for the KF and KE exercises: (a) traditional protocol (TP)-1 set of KE only to repetition failure; (b) paired sets with minimal allowable rest (PMR)-1 set of KF followed immediately by a set of KE; (c) P30-30-second rest between paired sets of KF and KE; (d) P1-1-minute rest between paired sets; (e) P3-3-minute rest between paired sets; and (f) P5-5-minute rest between paired sets. The number of repetitions performed and electromyographic (EMG) activity of vastus lateralis, vastus medialis (VM), and rectus femoris (RF) muscles were recorded during the KE set in each protocol. It was demonstrated that significantly greater KE repetitions were completed during the PMR, P30, and P1 protocols vs. the TP protocol. Significantly greater EMG activity was demonstrated for the RF muscle during the KE exercise in the PMR and P30 vs. the TP, P3, and P5, respectively. In addition, significantly greater EMG activity was demonstrated for the VM muscle during the PMR vs. all other protocols. The results of this study indicate that no rest or relatively shorter rest intervals (30 seconds and 1 minute) between APS might be more effective to elicit greater agonist repetition enhancement and muscle activation.

  16. MAXIMUM REPETITION PERFORMANCE AFTER DIFFERENT ANTAGONIST FOAM ROLLING VOLUMES IN THE INTER‐SET REST PERIOD

    Science.gov (United States)

    Škarabot, Jakob; Vigotsky, Andrew D.; Brown, Amanda Fernandes; Gomes, Thiago Matassoli; Novaes, Jefferson da Silva

    2017-01-01

    Background Foam rollers, or other similar devices, are a method for acutely increasing range of motion, but in contrast to static stretching, do not appear to have detrimental effects on neuromuscular performance. Purpose The purpose of this study was to investigate the effects of different volumes (60 and 120 seconds) of foam rolling of the hamstrings during the inter‐set rest period on repetition performance of the knee extension exercise. Methods Twenty‐five recreationally active females were recruited for the study (27.8 ± 3.6 years, 168.4 ± 7.2 cm, 69.1 ± 10.2 kg, 27.2 ± 2.1 m2/kg). Initially, subjects underwent a ten‐repetition maximum testing and retesting, respectively. Thereafter, the experiment involved three sets of knee extensions with a pre‐determined 10 RM load to concentric failure with the goal of completing the maximum number of repetitions. During the inter‐set rest period, either passive rest or foam rolling of different durations (60 and 120 seconds) in a randomized order was employed. Results Ninety‐five percent confidence intervals revealed dose‐dependent, detrimental effects, with more time spent foam rolling resulting in fewer repetitions (Cohen's d of 2.0 and 1.2 for 120 and 60 seconds, respectively, in comparison with passive rest). Conclusion The results of the present study suggest that more inter‐set foam rolling applied to the antagonist muscle group is detrimental to the ability to continually produce force. The finding that inter‐set foam rolling of the antagonist muscle group decreases maximum repetition performance has implications for foam rolling prescription and implementation, in both rehabilitation and athletic populations. Level of evidence 2b PMID:28217418

  17. MAXIMUM REPETITION PERFORMANCE AFTER DIFFERENT ANTAGONIST FOAM ROLLING VOLUMES IN THE INTER-SET REST PERIOD.

    Science.gov (United States)

    Monteiro, Estêvão Rios; Škarabot, Jakob; Vigotsky, Andrew D; Brown, Amanda Fernandes; Gomes, Thiago Matassoli; Novaes, Jefferson da Silva

    2017-02-01

    Foam rollers, or other similar devices, are a method for acutely increasing range of motion, but in contrast to static stretching, do not appear to have detrimental effects on neuromuscular performance. The purpose of this study was to investigate the effects of different volumes (60 and 120 seconds) of foam rolling of the hamstrings during the inter-set rest period on repetition performance of the knee extension exercise. Twenty-five recreationally active females were recruited for the study (27.8 ± 3.6 years, 168.4 ± 7.2 cm, 69.1 ± 10.2 kg, 27.2 ± 2.1 m(2)/kg). Initially, subjects underwent a ten-repetition maximum testing and retesting, respectively. Thereafter, the experiment involved three sets of knee extensions with a pre-determined 10 RM load to concentric failure with the goal of completing the maximum number of repetitions. During the inter-set rest period, either passive rest or foam rolling of different durations (60 and 120 seconds) in a randomized order was employed. Ninety-five percent confidence intervals revealed dose-dependent, detrimental effects, with more time spent foam rolling resulting in fewer repetitions (Cohen's d of 2.0 and 1.2 for 120 and 60 seconds, respectively, in comparison with passive rest). The results of the present study suggest that more inter-set foam rolling applied to the antagonist muscle group is detrimental to the ability to continually produce force. The finding that inter-set foam rolling of the antagonist muscle group decreases maximum repetition performance has implications for foam rolling prescription and implementation, in both rehabilitation and athletic populations. 2b.

  18. Electron Acceleration at Pulsar Wind Termination Shocks

    Science.gov (United States)

    Giacchè, S.; Kirk, John G.

    2017-02-01

    We study the acceleration of electrons and positrons at an electromagnetically modified, ultrarelativistic shock in the context of pulsar wind nebulae. We simulate the outflow produced by an obliquely rotating pulsar in proximity of its termination shock with a two-fluid code that uses a magnetic shear wave to mimic the properties of the wind. We integrate electron trajectories in the test-particle limit in the resulting background electromagnetic fields to analyze the injection mechanism. We find that the shock-precursor structure energizes and reflects a sizable fraction of particles, which becomes available for further acceleration. We investigate the subsequent first-order Fermi process sustained by small-scale magnetic fluctuations with a Monte Carlo code. We find that the acceleration proceeds in two distinct regimes: when the gyroradius {r}{{g}} exceeds the wavelength of the shear λ, the process is remarkably similar to first-order Fermi acceleration at relativistic, parallel shocks. This regime corresponds to a low-density wind that allows the propagation of superluminal waves. When {r}{{g}}< λ , which corresponds to the scenario of driven reconnection, the spectrum is softer.

  19. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  20. Non-word repetition in 2-year-olds: Replication of an adapted paradigm and a useful methodological extension.

    Science.gov (United States)

    Torrington Eaton, Catherine; Newman, Rochelle S; Ratner, Nan Bernstein; Rowe, Meredith L

    2015-07-01

    Accurate non-word repetition (NWR) has been largely attributed to phonological memory, although the task involves other processes including speech production, which may confound results in toddlers with developing speech production abilities. This study is based on Hoff, Core and Bridges' adapted NWR task, which includes a real-word repetition (RWR) condition. We tested 86 typically developing 2-year-olds and found relationships between NWR and both receptive and expressive vocabulary using a novel measure that controls for speech production by comparing contextually matched targets in RWR. Post hoc analyses demonstrated the influence of lexical and sublexical factors in repetition tasks. Overall, results illustrate the importance of controlling for speech production differences in young children and support a useful methodological approach for testing NWR.

  1. Shock Protection of Portable Electronic Products: Shock Response Spectrum, Damage Boundary Approach, and Beyond

    Directory of Open Access Journals (Sweden)

    Suresh Goyal

    1997-01-01

    Full Text Available The pervasive shock response spectrum (SRS and damage boundary methods for evaluating product fragility and designing external cushioning for shock protection are described in detail with references to the best available literature. Underlying assumptions are carefully reviewed and the central message of the SRS is highlighted, particularly as it relates to standardized drop testing. Shortcomings of these methods are discussed, and the results are extended to apply to more general systems. Finally some general packaging and shock-mounting strategies are discussed in the context of protecting a fragile disk drive in a notebook computer, although the conclusions apply to other products as well. For example, exterior only cushioning (with low restitution to reduce subsequent impacts will provide a slenderer form factor than the next best strategy: interior cushioning with a “dead” hard outer shell.

  2. TEMPERATURE MEASUREMENT OF REFLECTED SHOCK WAVE BY USING CHEMICAL INDICATOR

    Institute of Scientific and Technical Information of China (English)

    Cui Jiping; He Yuzhong; Wang Su; Wang Jing; Fan Bingcheng

    2000-01-01

    This report describes a new method for measuring the temperature of the gas behind the reflected shock wave in shock tube,corresponding to the reservoir temperature of a shock tunnel,based on the chemical reaction of small amount of CF4 premixed in the test gas.The final product C2F4 is used as the temperature indicator,which is sampled and detected by a gas chromatography in the experiment.The detected concentration of C2F4 is correlated to the temperature of the reflected shock wave with the initial pressure P1 and test time γas parameters in the temperature range 3300K<T<5600K,pressure range 5kPa<P1<12kPa andγ≈0.4ms.

  3. Quasiperpendicular high Mach number Shocks

    CERN Document Server

    Sulaiman, A H; Dougherty, M K; Burgess, D; Fujimoto, M; Hospodarsky, G B

    2015-01-01

    Shock waves exist throughout the universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasi-perpendicular shocks across two orders of magnitude in Alfven Mach number (MA) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted timescale of ~0.3 {\\tau}c, where {\\tau}c is the ion gyroperio...

  4. CMEs as a Shock Structure

    Science.gov (United States)

    Muñoz Martínez, Guadalupe; Becerril, Carlos; Lopez-Lopez, Jose Luis

    Interplanetary shocks are associated to approximately one third of the CMEs detected in the interplanetary medium. Even though they have been associated to fast CMEs (V>1000 km/s) it has been shown that some slow ones (V 300 km/s) presented shocks at 1 AU. The structure of the features observed in coronograph images can be hardly compared to the ones detected beyond the coronograph field of view, where the shock is clearly identify. For a few cases, the shock in front of the CME has been distinguish in white light images, but, is there a real visual difference between the CME itself and the considered shock? In this work we compare the optical characteristics of CMEs and some hydrodynamic parameters of ICMEs to show that the feature observed in white light images can be considered as a shock structure.

  5. Disclosure and the Cost of Capital: Evidence from Firms' Responses to the Enron Shock

    OpenAIRE

    Christian Leuz; Catherine Schrand

    2009-01-01

    This paper examines the link between disclosure and the cost of capital. We exploit an exogenous cost of capital shock created by the Enron scandal in Fall 2001 and analyze firms' disclosure responses to this shock. These tests are opposite to the typical research design that analyzes cost of capital responses to disclosure changes. In reversing the tests and using an exogenous shock, we mitigate concerns about omitted variables in traditional cross-sectional disclosure studies. We estimate s...

  6. Geometrical on-the-fly shock detection in smoothed particle hydrodynamics

    Science.gov (United States)

    Beck, A. M.; Dolag, K.; Donnert, J. M. F.

    2016-05-01

    We present an on-the-fly geometrical approach for shock detection and Mach number calculation in simulations employing smoothed particle hydrodynamics (SPH). We utilize pressure gradients to select shock candidates and define up- and downstream positions. We obtain hydrodynamical states in the up- and downstream regimes with a series of normal and inverted kernel weightings parallel and perpendicular to the shock normals. Our on-the-fly geometrical Mach detector incorporates well within the SPH formalism and has low computational cost. We implement our Mach detector into the simulation code GADGET and alongside many SPH improvements. We test our shock finder in a sequence of shock tube tests with successively increasing Mach numbers exceeding by far the typical values inside galaxy clusters. For all shocks, we resolve the shocks well and the correct Mach numbers are assigned. An application to a strong magnetized shock tube gives stable results in full magnetohydrodynamic setups. We simulate a merger of two idealized galaxy clusters and study the shock front. Shock structures within the merging clusters as well as the cluster shock are well captured by our algorithm and assigned correct Mach numbers.

  7. Physics of collisionless shocks - theory and simulation

    CERN Document Server

    Novo, A Stockem; Fonseca, R A; Silva, L O

    2015-01-01

    Collisionless shocks occur in various fields of physics. In the context of space and astrophysics they have been investigated for many decades. However, a thorough understanding of shock formation and particle acceleration is still missing. Collisionless shocks can be distinguished into electromagnetic and electrostatic shocks. Electromagnetic shocks are of importance mainly in astrophysical environments and they are mediated by the Weibel or filamentation instability. In such shocks, charged particles gain energy by diffusive shock acceleration. Electrostatic shocks are characterized by a strong electrostatic field, which leads to electron trapping. Ions are accelerated by reflection from the electrostatic potential. Shock formation and particle acceleration will be discussed in theory and simulations.

  8. Masked repetition priming hinders subsequent recollection but not familiarity: A behavioral and event-related potential study.

    Science.gov (United States)

    Li, Bingbing; Wang, Wei; Gao, Chuanji; Guo, Chunyan

    2016-10-01

    The present study used the masked repetition priming paradigm in the study phase and the R/K paradigm in the test phase to investigate whether repetition priming can hinder recognition memory and which recognition process (familiarity or recollection) is hindered. Event-related potentials (ERPs) in the study and test phase were recorded to explore the temporal course of how repetition priming hinders subsequent recognition memory and which old/new effect (FN400 or LPC) is affected. Converging behavioral and ERP results indicated that masked repetition priming hindered subsequent recollection but not familiarity. The analysis of ERP priming effects in the study phase indicated that primed words were associated with less negative N400 and less positive LPC compared to unprimed words. The analysis of the priming effect as a function of subsequent memory revealed that only the LPC priming effect was predictive of priming effect on subsequent memory, which suggested that the "prediction-error" account might be a possible explanation of how repetition priming affects subsequent recognition memory.

  9. Stability of oblique shock front

    Institute of Scientific and Technical Information of China (English)

    CHEN; Shuxing(陈恕行)

    2002-01-01

    The stability of the weak planar oblique shock front with respect to the perturbation of the wall is discussed. By the analysis of the formation and the global construction of shock and its asymptotic behaviour for stationary supersonic flow along a smooth rigid wall we obtain the stability of the solution containing a weak planar shock front. The stability can be used to single out a physically reasonable solution together with the entropy condition.

  10. Picosecond Laser Shock Peening of Nimonic 263 at 1064 nm and 532 nm Wavelength

    Directory of Open Access Journals (Sweden)

    Sanja Petronic

    2016-02-01

    Full Text Available The paper presents a study on the surface modifications of nickel based superalloy Nimonic 263 induced by laser shock peening (LSP process. The process was performed by Nd3+:Yttrium Aluminium Garnet (YAG picosecond laser using the following parameters: pulse duration 170 ps; repetition rate 10 Hz; pulse numbers of 50, 100 and 200; and wavelength of 1064 nm (with pulse energy of 2 mJ, 10 mJ and 15 mJ and 532 nm (with pulse energy of 25 mJ, 30 mJ and 35 mJ. The following response characteristics were analyzed: modified surface areas obtained by the laser/material interaction were observed by scanning electron microscopy; elemental composition of the modified surface was evaluated by energy-dispersive spectroscopy (EDS; and Vickers microhardness tests were performed. LSP processing at both 1064 nm and 532 nm wavelengths improved the surface structure and microhardness of a material. Surface morphology changes of the irradiated samples were determined and surface roughness was calculated. These investigations are intended to contribute to the study on the level of microstructure and mechanical properties improvements due to LSP process that operate in a picosecond regime. In particular, the effects of laser wavelength on the microstructural and mechanical changes of a material are studied in detail.

  11. Grain Destruction in Interstellar Shocks

    OpenAIRE

    1995-01-01

    Interstellar shock waves can erode and destroy grains present in the shocked gas, primarily as the result of sputtering and grain-grain collisions. Uncertainties in current estimates of sputtering yields are reviewed. Results are presented for the simple case of sputtering of fast grains being stopped in cold gas. An upper limit is derived for sputtering of refractory grains in C-type MHD shocks: shock speeds $v_s \\gtrsim 50 \\kms$ are required for return of more than 30\\% of the silicate to t...

  12. Quasiperpendicular High Mach Number Shocks

    Science.gov (United States)

    Sulaiman, A. H.; Masters, A.; Dougherty, M. K.; Burgess, D.; Fujimoto, M.; Hospodarsky, G. B.

    2015-09-01

    Shock waves exist throughout the Universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this Letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasiperpendicular shocks across 2 orders of magnitude in Alfvén Mach number (MA ) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted time scale of ˜0.3 τc , where τc is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and MA and focus on the magnetic structure of such shocks to further show that for the same MA , a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.

  13. Management of refractory cardiogenic shock.

    Science.gov (United States)

    Reyentovich, Alex; Barghash, Maya H; Hochman, Judith S

    2016-08-01

    Cardiogenic shock is a life-threatening condition that occurs in response to reduced cardiac output in the presence of adequate intravascular volume and results in tissue hypoxia. Cardiogenic shock has several underlying aetiologies, with the most common being acute myocardial infarction (AMI). Refractory cardiogenic shock presents as persistent tissue hypoperfusion despite administration of adequate doses of two vasoactive medications and treatment of the underlying aetiology. Investigators of the SHOCK trial reported a long-term mortality benefit of emergency revascularization for shock complicating AMI. Since the publication of the SHOCK trial and subsequent guideline recommendations, the increase in community-based use of percutaneous coronary intervention for this condition has resulted in a significant decline in mortality. Despite these successes in the past 15 years, mortality still remains exceptionally high, particularly in patients with refractory cardiogenic shock. In this Review, we discuss the aetiology and pathophysiology of cardiogenic shock and summarize the data on the available therapeutics and their limitations. Although new mechanical circulatory support devices have been shown to improve haemodynamic variables in patients with shock complicating AMI, they did not improve clinical outcomes and are associated with high costs and complications.

  14. Shortening of subjective visual intervals followed by repetitive stimulation.

    Directory of Open Access Journals (Sweden)

    Fuminori Ono

    Full Text Available Our previous research demonstrated that repetitive tone stimulation shortened the perceived duration of the preceding auditory time interval. In this study, we examined whether repetitive visual stimulation influences the perception of preceding visual time intervals. Results showed that a time interval followed by a high-frequency visual flicker was perceived as shorter than that followed by a low-frequency visual flicker. The perceived duration decreased as the frequency of the visual flicker increased. The visual flicker presented in one hemifield shortened the apparent time interval in the other hemifield. A final experiment showed that repetitive tone stimulation also shortened the perceived duration of preceding visual time intervals. We concluded that visual flicker shortened the perceived duration of preceding visual time intervals in the same way as repetitive auditory stimulation shortened the subjective duration of preceding tones.

  15. The relationship between task repetition and language proficiency

    Directory of Open Access Journals (Sweden)

    Ahmad Mojavezi

    2014-01-01

    Full Text Available Task repetition is now considered as an important task-based implementation variable which can affect complexity, accuracy, and fluency of L2 speech. However, in order to move towards theorizing the role of task repetition in second language acquisition, it is necessary that individual variables be taken into account. The present study aimed to investigate the way task repetition correlates with language proficiency and the differential effects that task repetition might have on the complexity, accuracy, and fluency of L2 learners with different levels of proficiency. Fifty language learners of different levels of proficiency, selected from two different language centers, participated in this study. They were asked to perform an oral narrative task twice with a one-week interval. Results revealed that, compared to the participants with lower L2 proficiency, participants with higher levels of L2 proficiency produced more complex, accurate, and fluent speech on the second encounter with the same task.

  16. The repetition effect in building and construction works

    DEFF Research Database (Denmark)

    Gottlieb, Stefan Christoffer; Haugbølle, Kim

    are then applied on the Public Transport Authorities' main account structure of units and costs, and a method for assessing the possibilities of achieving effects of repetition for each account is described. Finally, the report summarises the core conditions necessary to take into consideration in relation......This report summarises the results from the work undertaken for the Public Transport Authority on the effect of learning and repetition in building and construction works. The results are applied by the Public Transport Authority in a new budgeting model, while the agency investigates...... the establishment of a new railway between Copenhagen and Ringsted. Drawing on an extensive literature review, the effect of repetition is determined to be in the range of 6-12 %. Further, the report identifies a series of factors affecting the possibilities of achieving effects of repetition. These factors...

  17. Neural dynamics during repetitive visual stimulation

    Science.gov (United States)

    Tsoneva, Tsvetomira; Garcia-Molina, Gary; Desain, Peter

    2015-12-01

    Objective. Steady-state visual evoked potentials (SSVEPs), the brain responses to repetitive visual stimulation (RVS), are widely utilized in neuroscience. Their high signal-to-noise ratio and ability to entrain oscillatory brain activity are beneficial for their applications in brain-computer interfaces, investigation of neural processes underlying brain rhythmic activity (steady-state topography) and probing the causal role of brain rhythms in cognition and emotion. This paper aims at analyzing the space and time EEG dynamics in response to RVS at the frequency of stimulation and ongoing rhythms in the delta, theta, alpha, beta, and gamma bands. Approach.We used electroencephalography (EEG) to study the oscillatory brain dynamics during RVS at 10 frequencies in the gamma band (40-60 Hz). We collected an extensive EEG data set from 32 participants and analyzed the RVS evoked and induced responses in the time-frequency domain. Main results. Stable SSVEP over parieto-occipital sites was observed at each of the fundamental frequencies and their harmonics and sub-harmonics. Both the strength and the spatial propagation of the SSVEP response seem sensitive to stimulus frequency. The SSVEP was more localized around the parieto-occipital sites for higher frequencies (>54 Hz) and spread to fronto-central locations for lower frequencies. We observed a strong negative correlation between stimulation frequency and relative power change at that frequency, the first harmonic and the sub-harmonic components over occipital sites. Interestingly, over parietal sites for sub-harmonics a positive correlation of relative power change and stimulation frequency was found. A number of distinct patterns in delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz) and beta (15-30 Hz) bands were also observed. The transient response, from 0 to about 300 ms after stimulation onset, was accompanied by increase in delta and theta power over fronto-central and occipital sites, which returned to baseline

  18. Autism and exergaming: effects on repetitive behaviors and cognition

    OpenAIRE

    Anderson-Hanley C; Tureck K; Schneiderman RL

    2011-01-01

    Cay Anderson-Hanley, Kimberly Tureck, Robyn L Schneiderman Department of Psychology, Union College, Schenectady, NY, USA Abstract: Autism is a neurodevelopmental disorder that leads to impairment in social skills and delay in language development, and results in repetitive behaviors and restricted interests that impede academic and social involvement. Physical exercise has been shown to decrease repetitive behaviors in autistic children and improve cognitive function across the life-span. Ex...

  19. Breakdown behavior of electronics at variable pulse repetition rates

    OpenAIRE

    Korte, S.; H. Garbe

    2006-01-01

    The breakdown behavior of electronics exposed to single transient electromagnetic pulses is subject of investigations for several years. State-of-the-art pulse generators additionally provide the possibility to generate pulse sequences with variable pulse repetition rate. In this article the influence of this repetition rate variation on the breakdown behavior of electronic systems is described. For this purpose microcontroller systems are examined during line-led exposure to pulses with repe...

  20. Analysis of repetitive DNA in chromosomes by flow cytometry.

    Science.gov (United States)

    Brind'Amour, Julie; Lansdorp, Peter M

    2011-06-01

    We developed a flow cytometry method, chromosome flow fluorescence in situ hybridization (FISH), called CFF, to analyze repetitive DNA in chromosomes using FISH with directly labeled peptide nucleic acid (PNA) probes. We used CFF to measure the abundance of interstitial telomeric sequences in Chinese hamster chromosomes and major satellite sequences in mouse chromosomes. Using CFF we also identified parental homologs of human chromosome 18 with different amounts of repetitive DNA.